Dr. DoBB'S (OURNALof
COMPUTER
(Calisthenics Orthodontia
Running Light Without Overbyte
A Reference Journal for Users of Home Computers
Volu me Th ree
I’i The People’s Computer Company Series
4
\
j
Dr. Dobb’s Journal
of Computer Calisthenics 6 Orthodontia,
Volume Three
1
Dr. DoBB'S JOURNALof
COMPUTER
(Calisthenics ^5 Orthodontia
Running Light Without Overbyte
A Reference Journal for Users of Home Computers
Volume Th ree
K3 The People's Computer Company Series
[7TI HAYDEN BOOK COMPANY, INC.
1 H I Rochelle Park, New Jersey
Acknowledgments
Profuse thanks to all the authors and readers who contribute articles and share
ideas with Dr. Dobb’s. Dr. Dobb's Journal, distributed worldwide, owes its
existence to you. Thanks also to the employees and other supporters of People’s
Computer Company who have seen Dr. Dobb’s through its inception, growing
pains and success.
Full-page computer art by David Dameron.
Linocut of griffin by Wendy Palmer. The mythological griffin, half lion and half
eagle, has long stood as an enemy of ignorance.
ISBN 0-8104-54904
Copyright ©1980 by People’s Computer Company. All rights reserved. No
part of this book may be reprinted, or reproduced, or utilized in any form or
by any electronic, mechanical, or other means, now known or hereafter invented,
including photocopying and recording, or in any information storage and
retrieval system, without permission in writing from the Publisher.
Printed in the United States of America
3 4 5 6 7 8 9 PRINTING
81 82 83 84 85 86 87 88
YEAR
Editors Prefa ce
The third volume of Dr. Dobb's Journal represented a year of growth and maturity in the
field of small computers, a maturity evident among manufacturers and users. Although Dr.
Dobb’s has always been primarily a software journal, Volume III reflects this increased sophisti¬
cation with a substantial increase in the number of software articles. It branched out to include
more microprocessors, most notably the 6502, used in the Apple, PET, and KIM 1. Software
was somewhat different from that submitted in 1977; the earlier emphasis on systems yielded
to the exploration of programming languages and to theoretical articles on computing in
general. New implementations of languages for microcomputers SAM-76, UCSD PASCAL,
BASEX, and FORTH were given extensive treatment.
Yet, there were still specialized applications, utilities, and unique discoveries made by
readers eager to share their findings. Graphics programs for various systems, a Z-80 debugger, a
KIM-1 editor, a renumbering program for the Apple, several 6502 cassette interface routines,
and much, much more were published.
Many of the articles stressed technique rather than specific implementation, which speaks
for the sophistication of the readers. As the year progressed, readers were able to adapt tech¬
niques and examples to their particular hardware system requirements. Specific applications
articles stressed the algorithmic aspect more than in the past. (For example, see Richard
Emerson’s “Shorter Printer Driver for PolyMorphic BASIC.” The article gives a specific appli¬
cation, and gives the reader introduction to the concept of circular buffers. J.M. Terry offers
an equally informative discussion of the basics of list processing; Mike Gabrielson gives a clear
and entertaining look at “Binary Tree Manipulation.”)
Reader debates ranged from controversies over hex versus octal notation to the relative
merits of languages. Follow, for example, the lively exchanges between the proponents of
FORTH and STRUBAL to get the flavor of discussion.
By the end of 1978, it was apparent that small computers could have as great an effect on
human society as printing has had. A tremendous base of knowledge for computers had been
established. Industry gurus were losing sleep trying to predict where it was all going to lead.
And where will it lead?
Among the effects the microcomputer will have on our world will be a profound increase
in the volume and quantity of communication. When small computers are linked by means of
satellites to other computers as well as to large data bases, the world will see an information
revolution before which the invention of printing will pale. That day has been brought closer
by the readers and contributors of Dr Dobb’s.
Tom Williams
Editor, Volume III
Contents
VOLUME 3, NUMBER 1, 1978
13
14
15
16
18
20
28
48
The Heath H-8 “Evaluation”: I Think We Blew It!
Memory Test for 6502 Carl Moser
Consarn That H-8! Craig A. Pearce
Challenging Challenger’s ROMs Stephen P. Smith
Is Your Assembly Language Program Well Structured?
ISIS: Anatomy of a Real-World Operating System
The SAM76 Language Ancelme Roichel
An 8080 Disassembler & Support Software for SOL
Jim C. Warren, Jr., Editor
Webb Simmons
Perry C. Hutchison
Don Van Dyke
VOLUME 3, NUMBER 2, 1978
60 ET TU, KLATU? Stanford News Service
61 Decoding Efficiency & Speed: Pros & Cons of Table Look-up H.T. Gordon
64 MITS 4.0/4.1 BASIC Searcher/Patcher James Monagan
66 A Simple Technique for Static Relocation of Absolute Machine Code
Gary A. Kildall
70 Relocation is Not Just Moving Programs Richard L. Roth
78 Absolutely Dazzling Dazzleware Gordon French & Gregory Yob
86 Dazzler Driver Subroutine and a “Chase” Phillip Simpson
98 Z-80 RAM Tester John MacDougall
99 Mini Editor for 8080 PILOT Tim Scully
101 The Last Rehash of Beau Hex? letters in the unending(?) hex/octal debate
VOLUME 3, NUMBER 3, 1978
106 Renumbering and Appending BASIC Programs on the Apple-II Computer
Steve Wozniak
112 STRUBAL: A Structured BASIC Compiler Robert Grappel
113 A Z-80 Tracer Arthur W. Cline
115 A KIM Binary Calculator John Eaton
118 Status of the UCSD PASCAL Project Kenneth Bowles
122 ACT — An 8080 Macroprocessor — Part I Alex Cecil
148 SAM 76 — Additional Comments Ancelme Roichel
VOLUME 3, NUMBER 4, 1978
152 List Processing Unravelled: Pointers, Chains, Rings and Trees J.M. Terry
157 The Oznaki “Life” Harvey A. Cohen
159 AIK Debugger for the Z-80 Les Hancock
166 Exit This Reviewer Jef Raskin
169 A Line-Oriented PILOT Editor David J. Morgan
174 ACT—An 8080 Macroprocessor — Part II Alex Cecil
VOLUME 3, NUMBER 5, 1978
198 Programming Language Translation Techniques W. M. McKeeman
211 Yet Another Body Ken Anderson
215 FORTH for Microcomputers John James
222 Resident Memory Test Systems Terry Ritter
228 EDITH A: A Revision of the Fylstra KIM -1 Editor Program H.T. Gordon
234 Proposed Standard for the S-100 Bus George Morrow and Howard Fullmer
VOLUME 3, NUMBER 6, 1978
244 Intelligent Terminal Implementation on the S-100 Bus Tim Pugh
257 Autodump Richard Emerson
263 High-Speed Cassette I/O for the KIM-1 Theodore E. Bridge
267 The Zilog Z-8 U.R. Source
270 LAZARUS Andrew Hertzfeld
273 A Tiny BASIC Extensions Package Leor Zolman
VOLUME 3, NUMBER 7, 1978
290 A Compact 8080 Disassembler & Dumper Richard Greenlaw
305 The Intel 8086 Mike Gabrielson
308 A IK Utilities Package for the Z-80 Les Hancock
313 A Shorter Printer Driver for PolyMorphic’s BASIC Richard B. Emerson
317 Fast Cassette Interface for the 6502 Carl Moser
320 A BASIC Renumbering Program John B. Trenholme
328 Custom File Routines for ALS-8 Larry A. Marek
332 Common PILOT: Progress Report Larry Kheriaty and George Gerhold
VOLUME3, NUMBER 8, 1978
338
354
358
360
364
367
372
376
EM8080: An 8080 Emulator for 6800 Systems Gary Gaugler
The Last of the First Aubrey Dahl
Lisp for the 6800 Fritz van der Wateren
FORTH Dump Programs John James
Making a New Case for the H-9 Terminal Howard L. Nurse
A Programmable IC Tester for KIM Joel Swank
Dumping Northstar Disk Files Titus Purdin
Vocal Memory Dump Phil Mork
i
V0LUME3, NUMBER 9, 1978
386 LEDIP: A KIM/6502 Line Editor Kiumi Akingbehin
395 Quick and Dirty Routines for BASIC Dennis Allison
398 The Digicast™ Project Jim Warren
400 POW: An 8080‘Processor of Words’ Herman Watson
412 Data-Boy™ Speech Processor James Anderson
416 Whatis: An 8080 Expression Evaluator Mike Gabrielson
VOLUME3, NUMBER 10, 1978
429 A LISP interpreter for the 8080 Darrel Van Buer
437 Curve-Fitting Using a Focal Interpreter on the KIM-1 Theodore E. Bridge
440 Binary Tree Manipulation on the 8080 Mike Gabrielson
443 Programming Languages and Standards David Chapman
444 SAM-76 Language Update Ancelme Roichel
447 The Heath H-8 System Tom Williams
451 BASEX: A Fast, Compact Interactive Compiler Paul K. Warme
457 Tiny GRAFIX for Tiny BASIC Joel Swank
459 The STD Bus Keith Britton
465 Copying a Diskette on Intel Double Density DOS Paul M. Julich
474 Index to Volumes One, Two, and Three
About
People’s Computer Company
People’s Computer Company was founded in 1972 to demystify computers by teaching
people how to use them. It is still carrying on that crusade through magazines, books and
informal classes.
As one of PCC’s founders, Bob Albrecht explained in the first issue of the PCC newspaper,
“Computers are mostly used against people instead of for people, used to control people in¬
stead of to free them. It’s time to change all that. We need a People’s Computer Company.”
Since then, in its role as a non-profit, educational corporation, PCC has published a news¬
paper, three magazines, and several books on home/personal computing. The Personal Com¬
puter NETwork, (PCNET) joined People’s Computer Company in March, 1979. PCNET is a
Bay Area, California group dedicated since 1977 to the development of personal computer-
based telecommunications. Computertown, U.S.A.!, a computer literacy project joined People’s
Computer Company in August, 1979. In the past PCC also operated a neighborhood computer
center, and a mail-order bookstore.
Today, the PCC magazines — Recreational Computing, Dr. Dobb’s Journal, and Computer
Music Journal — have a combined circulation of about 28,000 (paid subscribers plus news¬
stand sales).
People’s Computer Company sprang from the same roots as the Whole Earth Catalog.
Both were offshoots of the Portola Institute of Menlo Park, an organization dedicated to invest¬
igating and promoting the idea of alternative technology. For the founders of PCC, that meant
learning to use computers as a liberating force in society.
In PCC’s view, familiarity with computers breeds confidence and personal power. “The com¬
puter-liberated kid grows up to be an adult unafraid to challenge his bills — or anything else
in the world’s great electronic system,” says Albrecht.
People’s Computer Company publishes three magazines for three distinct audiences. The
oldest, Recreational Computing, is for the computer novice to the intermediate hobbyist. It
started out as a newspaper called People’s Computer Company, evolved into People’s Com¬
puters magazine, and took its present name with the January-February 1979 issue. The maga¬
zine is published bimonthly.
“It’s in the home—in a relaxed, recreational environment—that the real computer revolution
is going to take place over the next few years,” said Albrecht.
As the first publication in the personal computing field, Recreational Computing has
spawned imitators. “But we feel we have a very special niche,” says publisher Willard Holden.
“Recreational Computing takes risks that other publications don’t. We are willing to publish
articles that may be off-beat and outrageous if we think they will get people excited about the
possibilities of computers.”
Dr. Dobb’s Journal, PCC’s second publication, had its beginning in January 1976 as a short¬
term mimeographed forum for the newly written Tiny Basic language. Reader response was so
strong that the Journal went into steady publication. Most DDJ readers describe themselves as
having from intermediate to extensive computer experience.
Dr. Dobb’s Journal is a reference journal read worldwide. Ten percent of the circulation is
outside the United States. The magazine contains sophisticated discussions of programming
techniques and hardware modifications. About half of each issue is devoted to free software.
DDJ appears ten times a year.
Computer Music Journal, the third PCC publication, is at the forefront of new developments
in the computer music world. During the past 20 years, there has been extensive research in
applying computers to music. The results of this research are becoming more visible as digital
techniques transform music production, music analysis, and music recording.
Computer Music Journal, published since 1977, is a respected source for information in this
field. The Journal is distributed quarterly to universities, research institutes, and individual
subscribers in 27 countries.
People’s Computer Company occupies the second floor of a small office building in down¬
town Menlo Park. The 30 staff members, more than half of whom are part-time, have pro¬
fessional interests in education, art, musical composition, computer science and journalism.
People’s Computer Company
Box E
Menlo Park, CA 94025
dr. dobbs journal of
COMPUTER
C
alisthenics
60
rthodontia
Running Light Without Overbyte
Number 21
Box E, Menlo Park, CA 94025
Volume 3, Issue 1
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
Heath's H-8
The Heath H-8 “Evaluation”: 1 Think We Blew It! — Jim C. Warren, Jr., Editor 3
Consam That H-8! — Craig A. Pearce 5
a tongue-in-cheek scolding of DDJ
6502 Stuff
Memory Test for 6502 - Carl Moser 4
Challenging Challenger’s ROMs - Stephen P. Smith 6
Software Design & Implementations
Is Your Assembly Language Program Well Structured? — Webb Simmons 8
ISIS: Anatomy of a Real-World Operating System — Perry C. Hutchison 10
an "internal logic manual” for Intel's ISIS
The SAM76 Language — Ancelme Roichel 18
complete documentation of a powerful string & macro processor
An 8080 Disassembler & Support Software for SOL — Don Van Dyke
38
© David Dameron 1979
•5
THE HEATH H-8 “EVALUATION”:
I THINK WE BLEW IT!
Jim C. Warren, Jr., Editor, DDJ
In issue 19 of Dr. Dobb’s, we published a rather negative
evaluation (?) of Heath’s H-8, along with a detailed
response from Heath. The evaluation was written by a
person we know personally whose technical judgment has
proven to be fair and accurate in the past. At his request,
we withheld his identity from publication—an editorial
policy that is quite common among periodicals ... at least,
regarding “Letters to the Editor.”
In retrospect, it is beginning to appear that we were
wrong on several counts.
(1) . If we were going to publish an article, giving it the
strength of being a DDJ “evaluation”, then we should
have identified the author. While it may be appropriate to
withhold a writer’s identity when publishing a letter to
the editor, we have concluded that authors of articles—
and certainly of product evaluations—should be identified,
and we will do so in the future.
(2) . We have been receiving additional feedback from
other H-8 consumers, and have found it to be explicitly
contradictory to a number of complaints in the original
article we published. We have been publishing and will
continue to publish such follow-up information.
(3) . We currently have, in-house, an H-8 kit shipped to
us by Heath for evaluation. Tom Williams, our Associate
Editor, is currently in the process of constructing it and
has already found a number of points of disagreement
with the original negative evaluation. As soon as he finishes
the construction and testing of the kit, we will be
publishing his evaluation of the kit, as an evaluation per¬
formed by a Dr. Dobb’s Editor, in-house.
We would like to apologize to Heath and to our readers
for having published what is beginning to appear to have
been an inaccurate and poorly researched “evaluation”
of the H-8. It is no more appropriate to publish an inaccu¬
rate negative article concerning a product, than it is to
publish an inaccurate article that praises a product. Articles
are written by individuals, and evaluations require judgment
on the part of the individual doing the writing. In this
case, it appears that the author of the article erred in
significant aspects of his judgment, and that we erred in
trusting his judgment. For this, we apologize.
RS-232 ADAPTER FOR KIM
News Release Received: 77 Dec 20
The ADApter converts KIM’s 20 ma. current loop port to
an RS-232 port. ADA does not affect the baud rate and uses
standard power supplies. The unit comes complete with
instructions, is assembled and tested, and measures 3” x 3 VJ’
x 1 ”. KIM is isolated from the RS-232 device by optoisolators.
ADA sells for $24.50 with drilled, plated through solder
pads for all connections, or for $29.50 with barrier strips and
screw terminals. Connecticut Microcomputer, 150 Pocono Rd,
Brookfield, CT 06804, (203) 775 -9659.
UNSUPPORTED OPCODE PITFALLS
Dear Jim, Received: 78 Jan 9
Pardon my tardiness, but when I got around to the article
on 650X Opcodes (August 1977) it set off a sensitive nerve.
In my opinion, there are no words strong enough to convey
an adequate warning against investing any significant time and
effort in hardware or software that is either irreplaceable or
not yours to use.
Before you use unsupported “instructions” in an MPU,
before you buy that music board with the secret, proprietary,
irreplaceable kludge chip, before you buy that proprietary
computer language, ask yourself what you will do if your
marbles get taken away. Suppose the chip blows? They do,
you know. Suppose your supplier goes out of business?
Suppose he merely multiplies the annual support/royalty
charges by ten?
My advice is to do what knowledgeable people in the
electronics industry have usually done: unless it’s in the
nature of a throwaway, don’t even think about buying it
or renting it or using it unless you have a clear alternative
if your supplier starts to behave unacceptably, or ceases to
exist. People who disobey that injunction have been badly
burned in the past, and will be badly burned in the future.
So have fun with the unsupported opcodes, marvel at
the secret kludge chips, and read about the latest super-gizmo
proprietary packages. But don’t tie yourself too heavily to
any of them.
Cordially yours, 730 Witte Hall
Paul Schick Madison, Wise. 53706
ERROR ON MOSTEK ERRATA
Dear Mr. Warren: Received: 78 Jan 10
I recently received the October 1977 issue of Dr. Dobb’s
and have found a letter entitled “MOSTEK/Zilog Flag Flap”
which is in error and could mislead your readers.
MOSTEK is a fully licensed second source of the Z80 chip
set (CPU, PIO, CTC, CMA and SIO) designed by Zilog. As
such, MOSTEK fabricates the Z80chip setfrom masks designed
by Zilog with no problems.
Reader Caldwell’s confusion stems from an error in our first
printing of the MOSTEK Z80 Programming Manual. An
ERRATA sheet has been added to successive printings of the
manual to correct the errors and available to anyone who
contacts us regarding this matter.
Both the MOSTEK and Zilog Z80-CPU devices set the
carry flag when subtraction generates a borrow. This is also
compatible with the operation of the 8080A as the 8080A
instruction set is a subset of the Z80 instruction set.
MOSTEK is concerned that Caldwell’s letter in your pub¬
lication will mislead your readers. Therefore, we encourage
you to print this letter and the enclosed ERRATA sheet in
your next issue. If any of your readers have questions regard¬
ing this matter, feel free to contact me or any of our Field
Applications Engineers.
Regards, MOSTEK Corporation
James F. Vittera P.O. Box 169
Applications Engineering Carrollton, TX 75006
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 3
13
MEMORY TEST FOR 6502
Dear Mr. Warren: Received: 78 Jan 3
Enclosed is a source listing of a program which tests RAM
memory in 6502 based systems. I wrote this test after using
other memory test programs which did not perform a
complete test. The problem areas were untested chip selects,
and address line inputs. This program written in my assembler’s
source syntax (advertised in Vol.2 No. 8 of DDJ), performs
an exhaustive test of a user specified range of memory. The
I/O is arranged for 6502 TIM based systems but can be easily
changed.
The program performs two tests:
Test 1: Tests all memory cells for storage retention, and
shorted data and address lines. This is done by writing:
00 11 ... FF 00 11 . .. FF continually throughout
the memory range for the first pass. When this has been
written it is checked to validate the data. On the next
pass 01 02 ... FF 00 01 ... FF is written and check¬
ed. This continues for 256 (hex FF) passes until all possible
combinations of bit patterns have been used.
Test 2: Tests the RAM chip select inputs. This is the same as
test 1 except data 00 01 ... F2 00 01 ... F2 is used.
Before execution, enter the address of the start of the
memory to be tested in 00C0 (lo) and 00C1 (hi), and the end
of memory +1 in 00C2 (lo) and 00C3 (hi).
Execution begins at 0000 with the first test.
If an error occurs, it will be outputted in the following
form:
Address Test Pattern Error
xxxx yy zz
When test 1 runs to completion, a break will occur and
register A will contain El (signifying end of test 1). To exe¬
cute test 2, simply continue execution (type G to TIM moni¬
tor).
If errors occur, they will be of the same form as described
above. When test 1 has mn to completion, a break will
occur and register A will contain E2 signifying the end. To
continue execution at test 1, simply type G to the TIM
monitor. The address range entered in 00C0—00C3 is not
altered by the memory test program.
If errors occurred in test 2 but not in test 1, you can safely
assume a chip select malfunction (defective or not connected).
Usually a number of errors will occur in test 1 when the fault
is a single defective address input, data input, or data output.
If a continuous sequence of addresses with errors occur, the
problem is likely to be an open data input, or stuck at ‘1’ or
‘0’ data output.
If every 2nd, 4th, 8th, 16th or some power of 2 address
sequence with errors occur, check for defective address inputs.
If you are checking say 2102’s (1 x IK) and are specifying
a range of, say 4K of memory, and an error common to the
whole range occurs, the problem is likely to be in the power
leads, defective data or address buffers, stuck at ‘0’ address
inputs, stuck at ‘0’ data inputs, or stuck at ‘0’ data outputs.
In all of the above, you may have to examine the various
memory error patterns for some similarity in order to isolate
the defective component. This is especially true of the 1 x IK
2102 memory chip where each chip is devoted to a particular
data lead (D 0 — D 7 ).
Finally, since this program has a copyright assigned, I
waive this right for publication in DDJ only..
Sincerely, 3239 Linda Dr.
Carl Moser Winston-Salem, NC 27106
0901
000?
300 4
0004
000 s
0006
•COPYRIGHT 1977 nr CARL Mf)SER»
• ALL RIGHTS RESERVED.
MCS 653? MEMORY TEST
0007
PROGRAM
0009
0000
:USER ENTERS MEMORY TO RE TESTED STARTING
0010
:ADDRESS IN START* AND END ADDRESS IN ENQ.
0011
001?
9013
;these storage variaries are external in zero page.
0014
START
•OE «C0 USER ENTERS START OF mem. TO HE If
0015
END
•DE SC2 USER ENTERS FNO OF mfm. TO RE TES
0015
AD0RS
•OE SCI
0017
TEST*TYPF
•DE SC6
0019
TESWATRN
•DE SC7
0010
0 0 ? 0
0 0 ? 1
: ROM I/O CALLS
09??
TRY!
• DE 17?R1 OUTPUT A PACKED RYTE (TWO DIGIT'
00?1
SPACE?
.DE S 7174 OUTPUT TWO SPACES
0 0 ?4
CRLF
.DE S7?RA OUTPUT A CARRIAGE RETURN* LINE f
0025
00?6
09?7
• RA S0
00?9
0000
4 ?04
0020
MFM.TFST
LDX *3 ffl
000?
9EC640
00.10
six tes r *type test i
000S
?0 1 900
0031
JSR TEST*PGM
000A
4RE1
303?
LOA *F 1
0001
00
0033
RRK
000R
E4
0 434
NOP
000C
F4
0935
NOP
0000
EEC690
0036
INC TEST*TYPE TEST 2
0010
201900
0937
ISR TEST*PGM
0013
ARE?
0039
LOA «E?
0015
99
0930
RRK
001R
E4
9940
NO J
0017
E4
004 1
NOP
001R
4C0403
0042
JMP MEM* TES T
034 3
0 419
?09 4 7 ?
0044
TEST*PGM
JSR CRLF
00 IE
4 4 49
0 44 5
LOY *93 PATTERN REGISTER
0 0 ? 0
4?09
9 44 f.
LDX *33
002?
9FC700
004 7
ST* TEST*PATRN
00?S
4C?E09
9049
IMP N<*PASS
0940
0029
EEC704
0059
NY*PATRN
INC TEST*PATRN
0 4 ?H
0991
0051
RNF NX*PASS
00?D
60
005?
RTS
04? E
ACC70P
0353
N < • P A S S
LOr TFST*PATRN
0031
?0450«
. 0354
ISR 1N1♦ADORS
00 34
09
0055
LOOP1
TY A
00 35
9 1C4
0056
STA (ADDRS.Y) STORE PATTERN
0037
C1C4
0957
CMP ( ADDRS*Y) CHECK
0039
F 30 3
0359
RED N0*ERR1
0939
?09513
0050
JSR ERROR ADDRS* R ( A)• (ADORS.X)
043E
20SE49
9063
N0*ERR1
JSR 1NC* A ODRSC
0411
F305
0061
RET CK*PA TRN
4 04 3
296190
9 06?
JSR INC*RY
3 04 6
4 C 34 0 9
0063
JMP LOOP 1
0061
0049
4CC700
0065
CK*PATRN
LOY TEST**MTRN
994 C
?04509
0966
ISR 1Nl♦ADDRS INITIALIZE ADDRS
034E
09
0367
LOOP?
TYA
0959
C1C4
00F9
CMP (ADDRS.X)
90S?
F 9 4 3
0060
RED ND*ERR3
0054
?.MS30
39 70
JSR ERROR ADDRS* R(A)* (49DRS*X)
0957
?06 1(49
00 7 1
no* err ?
JSR INC*RY
0054
? 0 6 F 0 '4
917?
JSR 1 NC* ADDRSC
0050
D0F0
037.3
RNF LOOP?
005F
F0C7
0371
RED NX*PATRN
30 75
3076
9051
C9
0077
1NC*RY
1 NY
405?
4OC500
9379
LOA TF$T*TYPF
4055
F036
0070
RED E< 1 T1
0057
C0F 3
9090
CP Y *F1 RESET R(y ) TO CHECK CHIP SELECTS
0051
000?
039 1
RCC E<lTl
4059
4?i40
009?
LOY *00
4060
69
0093
E* i r i
RTS
0094
0395
04RE
EFC490
0096
1NC* 40DHSC
INC ADDRS
09 7 1
0 001
0397
HNE SKI«*m|
49 7 1
EEC509
0991
INC ADDRS**31
03 75
ADC ?09
0390
SK1P♦HI
LOA ENO
90 79
CDC440
3000
CMP ADORS
047C
0006
9901
RN 6 EXIT?
407E
ADC 109
000?
LOA FND.S31
399 1
CDC590
3001
CMP 4D0RS*«91
0394
60
0004
E* 1 T?
P T 5
3006
0006
9007
•OUTPUT ThF ERROR: ADDRESS* PATTERN* ERROR
00RC
49
00OO
ERROR
PMA
4095
4OC500
0000
LDA A0DRS*«91
3090
?0917?
0100
JSR TR»T OUTPUT ADDRS h|
0 99 C
4 DC 4 3 4
0101
LOA ADDRS
309E
?3R17?
0 10?
ISR T B Y T OUTPUT ADDRS LO
000?
?0 7 4 7
0133
ISR SPACE?
4915
69
0104
PI A
9005
? 71=41 7?
3195
JSR TRYT OUTPUT PATTERN
?0RR
237471
3106
ISR SPACE?
00OC
A1C4
3107
L D A (ADDRS.X)
P99E
?09 1 7 ?
9109
JSR TRYT OUTPUT ERROR IN MPMORY
0001
?40A 7?
31.10
JSR CRLF
(1414
69
0113
RTS
3111
311?
3111
INITlALIZE
ADDRS WITH START
0045
AOC400
0114
INI* 40DRS
LPA START
0049
9OC400
3115
STA ADORS
0049
AQC100
0116
LOA START.H31
40 4 E
9 D C 5 0 9
3117
STA ADDRS**'* 1
0091
50
0119
RTS
0119
0 1 ?0
Page 4
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
CONSARN THAT H-8!
Dear Sirs: Received: 78 Jan 12
I truly enjoyed the article by . . . hmmm . . . let’s see . . .
no name given, eh? Well, anyway, the article by (must be)
Dr. Dobbs (or maybe Dr. Duds) himself on the great review of
the Heath H8 microcomputer. Fantastic! What a swell job
of reviewing. The author really got to the point. You tell ’em
Doc.
The H8 HAS to be the worst 8080A microcomputer out.
Mine, running with 24K at the moment, actually runs correct¬
ly when switched on! No self respecting home computer
should do that. It even had the audacity to come up running
immediately after I completed building it! What will all the
tinkerers do with a system that actually runs ?
Unlike the original S-100 bus system I first built, the
H8 can’t destroy memory contents when a reset is performed.
The damn thing keeps preserving what is in RAM. Further¬
more, if you can believe it, this poor machine doesn’t even
let the novice write his own bootstrap program to use the
cassette interface .. . one is already in ROM ready to use for
loading or dumping. Some spoil sports these Heath people
are, aren’t they?
That angle rack mounting is really bad. Here, the boards
are rigidly secured on top, bottom and side, making this
excuse for a computer simple to transport, rather than having
the fun of stuffing newspaper or packing ‘pop-corn’ in so the
boards don’t snap off like some S-100 Systems. Since the
mounting bracket on each board also acts as a heat sink, the
fact that they are attached to the computer main frame can
dissipate the heat even better, and thus, you don’t have the
fun of leaving the top off the computer like on other
systems, nor the sheer pleasure of the fan constantly running
in your ears, since none is needed.
I was able to fix the problem of not enough stuff on the
boards that Doc brings up too. (After all, what fun is having
a circuit board made simple, with fewer parts to go wrong,
when a jumbled up board, taking three times as long to build is
much more impressive looking ... even if it doesn’t work.)
I just glued extra ICs on the board indiscriminately to make
things more complex!
At least ol’ Doc, the author of this H8 review, had enough
sense to leave off the metal clip supplied with the H8 (to be
placed by the keys mounted on the circuit board) so that his
board bends as the keys are hit. I, like a fool, followed the
Heath directions and put the clip on, which totally avoided the
problem of the bending board Doc points out in his article.
As soon as I finish this letter, I intend to immediately run up
and pull the clip off my machine so I can bend my front panel
board too!
Oh yes, and then there is that God awful OCTAL! My
Lord, what a sin! It takes someone almost 10 minutes to get
used to a new numbering system. I wish I were as lucky as
Doc, and have 8 thumbs on each hand so I could use Hexadeci¬
mal too.
The fact that you can monitor, both dynamically, as well
as statically any register, memory location or I/O port via
the front panel too is also a hardship. I’d much rather have
a string of LED lights to view and interpret. Or better yet,
no front panel at all, like the SOL or APPLE II. Where’s the
challenge in seeing what you’re doing?
I guess what’s really horrible, as Doc points out, is the fact
that there is no compatibility with existing S-100 cards.
No one is going to make H8 compatible cards (excusing the
already announced Godbout 12K RAM card, or some other
manufacturers who have also requested to manufacture H8
compatible cards). I mean, outside of them, there’s only
Heath.
By all means, Heath has really gone too far with the H8.
Swelled heads and too big for their britches, as Doc says.
They actually had the nerve to offer the typical hobbyist and
home user a microcomputer that actually works, has a
functional and useful front panel, compatible software,
memory boards that hold their contents rather than dropping
bits, I/O boards that operate correctly the first time they are
built, solid construction and a design that isn’t a rehash of all
the other hardware on the market today. Damn innovaters...
next thing you know, someone may offer documentation that
isn’t 10 mimeographed sheets (like a lot of other systems) and
give full support like the H8 documentation.
Do your readers know that the Heath people are actually
giving you software in the form of Basic, console debug,
text editor and assembler with the computer to get the user
going faster? Where’s that good old “We’ll get ’em on the
accessories!” rule that has become a standard in the industry?
The people at Heath even returned my phone calls on some
questions I had about the system; with right answers even!
Now what kind of computer manufacturer is that, that
actually RETURNS the users’ calls, with correct answers to
boot? No one else that I can think of.
And, I can see Doc’s dislike of the fact that only the Heath
part numbers are given on the schematics. Why make it easy
for the non-technician to order parts through Heath when
needed? Besides, I guess Doc has the same problem I have of
not knowing how to use the cross reference table in the
manual (each has one), which gives the user the standard,
industrial part number. Hell, you have to know how to match
up numbers to use a table like that!
Finally, I have personally gained some special knowledge
in writing styles. I am the author of the Microscene column in
65-Notes, a newsletter put out by the HP-65 Users Club (not
affiliated with Hewlett-Packard), which is read by some 1900
members. When I ran a poor review of a micro, I was actually
dumb enough to sign my name. I’ve learned now. This may
well be my last time I’ll sign any of my work that might bring
me criticism.
Let’s hope that Heath can do better next time, in producing
a piece of hardware that constantly requires revisions like the
other micro manufacturers, (with their various patches and
fixes). And, by all means, Mr. Warren, Jr., keep a high regard
for the author of this fine review, ol Doc Duds. He’s really
the best.
Oh, one more thing, Mr. Warren ... if you should find this
little note of some interest, please print it in the letters
column, rather than give it to “Doc Duds”. At least those
who subscribe to your magazine can read.
Sincerely, 2529 S. Home Avenue
Mr. Craig A. Pearce Berwyn, Illinois 60402
Conclusion of "Memory Test for the 6502"
14REI FILE: [ / = E*TFRN4l 3
/ST4»T = (1«CH
/TFSTMYPE = <*flC«
/SP4CE?=7374
TEST*PGM=a«nR
L OOP 1 = f*P 34
LOOP? = *)04F
FX I T 1=20FD
EX I 12 = 0084
END*PG* = 0»R2
/FND=0PC?
/TFST*P4TR N=fl0C7
/CPLF=7?8A
NX*P4TRN = i*fl?R
NO*F8R1=003F
NO*FR9?=0057
I *JC*4DDRSC = (?08E
ERROP=0*85
/4008S = f»«C4
/rnrT=7?Rl
VF M * TEST = 008 A
NX»P4SS=002E
CK*P4TRN=flfl49
INORY=0Pfi1
SKIP*HI=G37fi
IM*400RS=85I4S
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
15
CHALLENGING CHALLENGER’S ROMS
Dear Friends, Received: 77 Dec 28
I have just become the proud owner of an Ohio Scientific
Challenger with Basic in 8K of ROM and a monitor in V£K of
PROM. While I am delighted with its performance, I’m not
happy about the lack of documentation provided for the read
only memory. I’d like to use the utility routines which must
be buried there.
I tried hand decoding memory dumps, but that’s a labor¬
ious task. Then it occured to me to let Basic do the work for
me. Using the PEEK function, I wrote a disassembler to
convert the stored bytes into MOS Technology cross assembler
mnemonics and decimal operands. The monitor decoded
easily, revealing a basket of I/O goodies. The Basic ROMs
are yielding more slowly. They apparently contain a number
of tables which must be picked around carefully.
I’ve enclosed a copy of my program so that other 6502
users can reap the same benefits. It’s written, of course, in
OSI’s Microsoft Basic, but should be adaptable for PET
and Apple. I haven’t time to pursue refinements such as hex
conversion for addresses, recognition' of ASCII characters,
or automatic skips around tables. If another reader makes
these or other additions, I’d appreciate them sending me
a copy of the program.
Sincerely yours, P.O. Box 841
Stephen P. Smith Parksley, VA 23421
GOODIES FROM THE GOVERNMENT??
Dear Dr. Dobbs, Received: 77 Dec 29
Your readers might be interested in a government sponsored
software library. The National Aeronautics and Space Admin¬
istration (NASA) puts out a quarterly journal “Computer
Program Abstracts” which can be ordered from the Superin¬
tendent of Documents, U.S. Government Printing Office,
Washington DC, 20402 for $3.30/yr.
Be aware that most of the programs are of little use to the
average home computer freak. Not too many need a 4,062
line FORTRAN IV program for $480 to “calculate flow fields
in supersonic inlets”. But useful items do surface; like a 79
line BASIC program for “organizing and managing a collection
of articles dealing with a specific keyword or subject”;
program and documentation for $25. The programs are writ¬
ten for everything from IBM 370’s to HP-25’s. Costs range
from $15 to $2,500 with separate documentation running at
5 to 10 percent of the program price. If the documentation
meets the usual government specifications, it will be very
complete.
To sum up, the prices for this software are such that if you
find what you need here and you have a market for its services,
the government software would be a bargain.
Ronald N. Orr
1114 Harper Ave
Redondo Beach, CA 90278
LIST
ID PRINT "DISASSEMBLER FOR MOS TECHNOLOGY 650X"
20 PRINT "BY STEPHEN P. SMITH, PARKSLEY, VA
21 PRINT "VERSION 1.0, DECEMBER 13,1977
22 PRINT
30 DIM Nl(56),A(296),LS(3),T$(5)
40 DATA ADC,AND,ASL,BCC,BCS,8EQ,B1T,BM1,8NE,BPL,BKK,BVC,BVS,CLC,CLD
50 DATA CLI,CLV,CMP,CPX,CPY,DEC,DEX,DEY,E0R,INC,INX,I NY,JMP,JSR,LDA
60 DATA LDX,LDY,LSR,NOP,0RA,PHA,PHP,PLA,PLP,R0L,RTI,RTS,SBC,SEC ,SED
70 0ATA SEI,STA,STX,STY,TAX,TAY,TSX,TXA,TXS,TYA,ILLEGAL
80 FOR 1=1 TO 56
90 READ NS(1)
100 NEXT I
110 LS(0)=" "
120 LS(1)="#"
130 LS(2)="<"
140 L$<3)=" A"
150 TS(0)=" "
160 T$(I)=",X)"
170 TS(2)="),Y"
180 TSC3)=",X"
190 T$(4)=",Y"
200 TS(5)=")"
201 REM
202 REM EACH POSSIBLE V0RD IS ASSIGNED A FIVE DIGIT CODE
203 REM THE FIRST TWO DIGITS GIVE THE APPLICABLE MNEMONIC
204 REM THE THIRD GIVES THE TOTAL NUMBER OF BYTES IN THE INSTRUCTION
205 REM THE FORTH INDICATES WHICH OF 4 LEADING FIGURES IS TO BE PRINTED
207 REM THE FIFTH INDICATES WHICH OF 6 TRAILING FIGURES IS USED
208 REM
210 DATA 11100,35221,56100,56130,56100,35200, 3200,56100
220 DATA 37100,35210, 3130,56130,56100,35300, 3300,96100
230 DATA 13200,35222,56130,56100,56100,35203,56100,56100
240 DATA 14100,35304, 3203,56100,56100,35303, 3303,56130
250 DATA 29300, 2221,56100,56100, 7200, 2200,56100,56100
260 DATA 39100, 2210,56100,56100, 7300, 2300,56100,56100
270 DATA 8200, 2222,56130,56100,56100, 2203,56100,56100
280 DATA 44100, 2304,56100,56100,56100, 2303,56100,56100
290 DATA 41100,24221,56100,56100,56100,24200,33200,56100
300 DATA 36100,24210,33130,56130,28300,24300,56100,56100
310 DATA 12200,24222,56100,56100,56100,24203,33300,56100
320 DATA 16100,24304,33203,56100,56100,24303,33300,56100
330 DATA 42100, 1221,56100,56100,56100, 1200,56100,56100
340 DATA 38100, 1210,56100,56100,28325, 1300,56100,56100
350 DATA 13200, 1222,56100,56100,56100, 1203,56100,56100
360 DATA 46100, 1304,56100,56100,56100, 1303,56100,56100
370 DATA 56100,47221,56100,56100,49200,47200,48200,56100
380
DATA
23100,47210,53100,56100,49303,47300,48300,56100
7 65024,
65047
390
DATA
4200,47222,56100,56100,49200,47203,48204,56100
65024
LDA
64512
400
DATA
55100,47304,54100,56100,56100,47303,56100,56100
65027
LSR
A
410
DATA
32210,30221,31210,56100,32200,30200,31200,56100
65028
BCC
-4
420
DATA
51100,30210,50100,56100,32300,30300,31300,56100
65030
LDA
64513
430
DATA
5200,30222,56100,56100,32203,30203,31204,56100
65033
AND
# 127
440
DATA
17130,30304,52100,56100,32303,30303,31304,56100
6503 5
PHA
4 50
DATA
20210,18221,56100,56100,20200,18200,21200,56100
65036
LDA
64512
460
DATA
27100,18210,22100,56100,20300,18300.21300,56100
65039
LSR
A
470
DATA
9200,18222,56100,56100,56100,13203,21203,56100
65040
LSR
A
480
DATA
15100,18304,56100,56100,56100,18303,21303,56100
65041
BCC
-5
490
DATA
19213,43221,56100,56100,19200,43200,25200,56100
65043
PLA
500
DATA
26100,43210,34100,56100,19300,43300,25300,56100
65044
STA
64513
510
DATA
06200,43222,56100,56100,56100,43203,25203,56100
520
DATA
45100,43304,56100,56100,56100,43302,25303,56100
530
FOR
1=1 TO 256
BREAK IN
940
540
READ
A (I)
OK
550 NEXT I
560 PRINT "ENTER STARTING AND ENDING ADDRESSES"
570 INPUT S,E
580 REM BEGIN DISASSEMBLY
600 I=PEEK(S)
605 REM LOCATE AND DISMEMBER THE 5 DIGIT CODE
610 C = A(1+1)
620 M=INT(C/1000)
630 IF M=56 THEN 1000
631 IF M«1 THEN 1000
640 8 = 1NT(C/100)-M*10
650 P=1NT(C/10)-M*I00-8*10
660 Q=C-M*I000-D*100-P*ID
670 IF 8=1 THEN 800
675 REM SECOND BYTE OF INSTRUCTION
680 01=PEEK(S+1)
690 IF B=2 THEN 800
695 REM THIRD BYTE OF INSTRUCTION
700 D2=PEEK (S+2)
710 DI=D1+D2*256
720 REM SPECIAL TREATMENT IF BRANCH
800 IF M*4 THEN 900
810 IF M*13 THEN 900
820 IF DI«127 THEN 900
830 D1=-<254-D1)
900 PRINT S|TAB(10)|NS(M)|TAB(16)jLS(P);
902 IF D1=-123456 THEN 908
904 PRINT D1;T$(Q)|
908 D1=-123456
909 PRINT
910 S=S+B
911 REM NEXT INSTRUCTION
920 IF S«E THEN 600
930 PRINT TAB(30),"**♦*♦*****"
940 STOP
1000 PRINT "AT"|Sj" ";Ij" IS NOT A VALID OPCODE"
1010 PRINT "TERMINATING DISASSEMBLY"
1020 END
OK
RUN
DISASSEMBLER FOR MOS TECHNOLOGY 650X
BY STEPHEN P. SMITH, PARKSLEY, VA
VERSION 1.0, DECEMBER 13,1977
ENTER STARTING AND ENDING ADDRESSES
**********
Page 6
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
16
CONSUMER DO’s AND DON’T’s FROM A DEALER
Dear Dr. Dobb’s, Received: 78 Jan 9
I read with interest the article, “A Detailed Report on
Product Delivery ”in the last issue (Volume 2 Issue 9) of DDJ.
I thought that a few comments and suggestions from a com¬
puter dealer (we operate a retail computer outlet as part of
our business in Northern Florida) may be of interest to you
and your readers.
1) If at all possible, purchase products directly from a
local computer store in your area. Not only does this
permit you to see the merchandise working before you
buy it, but many times you can get it the very same
day you decide you want it. Additionally, if you have
problems, you will have somewhere to go. Unfortu¬
nately, many manufacturers give you the instant “well,
you’d better send it back” routine (ie, 2—8 weeks
delay) when you phone them.
2) If at all possible, DO NOT send the full amount in
advance for an item (ESPECIALLY for a new item)!
In my opinion, the MOST that a firm should ask in
advance is 25%. COD can be somewhat of a fail-safe
device, but unfortunately, not all firms will ship on
a COD basis. When a firm refuses to ship COD, it
makes me wonder... however, a non-COD policy
does not mean that a firm is not honest. CCD seems
to be the best way to go when purchasing a newly
introduced item from a new company.
3) If it sounds too good to be true in the ad, it probably
is (too good to be true). BEWARE!! Just becaase there
is a photo of an item in an advertisement, that in no
way means that that item is being produced or has
ever even existed! The big ad does not make a firm
reputable.
4) When ordering by mail, request that the finn imme¬
diately confirm receipt of your order by mail (you
might even include a postage-paid postcard for the
company to return to you) and also request an expect¬
ed shipping date. This eliminates the “we never re¬
ceived your order routine” that could crop up on
a long overdue shipment. You might also want to
invest in a long distance phone call and inquire as to
delivery times BEFORE you place an order and send
money.
5) If a firm is promising and not delivering (especially
if they have your money) do not hesitate to bug
and bother them with letters and phone calls. Many
times it is the person who yells the longest and loudest
that gets what he’s after. Do not hesitate to tell the
overdue or non-producing firm that you ar; writing
to several computer-related publications (ie, Dr.
Dobb’s , Byte, Kilobaud, Interface Age, etc.) and
advising them of your plight. It won’t make you a
friend of the company you are dealing with, but then
do you really want friends who take your money,
promise, and not deliver?
One final comment: I find unacceptable the statements in
the above mentioned article concerning the supposition that
it takes too much paperwork to notify customers of order
confirmations and delays. As far as I am concerned, it is an
OBLIGATION of a firm to notify customers of sny delay
beyond a stated delivery date. That’s not a public relations
add-on, it is just good business.
Sincerely, 2062 Liberty Street
Bobby Williams Jacksonville, FL 32206
S-100 PRO & CON CENSUS
Dr. Dobb’s, Received: 78 Jan 4
Read with interest ‘The Heath H-8: Pro & Con’. The Con
author’s first evaluation (?) point was that the H-8 is not S-100
compatible. My first negative point would be that it is not
Z-80 based. As far as the bus structure not being S-100, well
that is still an open question.
The Pro author’s comments about the S-100 are just as
emotional as the Con author’s criticism of the H-8. And all
along I thought this hobby was basically logical (l’s and 0’s
and that sort of thing). Someone even told me that program¬
ming forces one to disciplined thinking.
My main rebuttal to the Pro author is that “you will find
that over 95% of them (S-100 boards) are memory cards of
some configuration.” My count was in decimal—not octal or
hex, so the following could be inaccurate.
From R.E. Purser’s list of S-100 Bus Compatible Boards/
Systems, which has been reprinted in Interface Age and
Creative Computing :
Being late in the ‘eve, my count is:
RAM memory boards
56
PROM memory boards
33
Total
89
Serial & Parallel I/O
Boards
32
Total of both
121
95% of 200 (a rounded figure) is 190 memory boards. Now
my count is not a “critical look”—just a midnight counting.
Regarding compatibility of the S-100, the Pro author is
right, there isn’t much beyond the basically defined pins.
Since no one knows how much incompatibility exists, I
decided to find out.
The results of my labor should appear in a future issue of
Kilobaud. I would have given it to y’all, but I had to recover
my postage costs.
Open question: If the majority of magazine issues are sold
to subscribers, why are we the last to receive them (i.e. after
the newstands)? Mailing in bulk by UPS to stores is no excuse.
Give them to UPS a couple weeks after the subscription copies
have been mailed.
Pa y
Bill Fuller
1018F SE 8th St
Grand Prairie, TX 75051
Bill, your complaint is just, but we simply don’t have space
to store the bulk issues. They do go out somewhat after the
subscriptions are mailed but even at that we have no way of
knowing how long the subscriber copies will spend in the Post
Office’s aging bins before they ’re finally delivered. -TRW
SOUTHERN CALIFORNIA DEALERS
ASSOCIATION
News Release Received: 78 Jan 3
The Southern California Computer Dealers Association has
been formed, as a non-profit corporation, covering the Santa
Barbara to San Diego area. Membership is limited to bona-
fide stores which sell microcomputers for personal, business,
industrial, or educational use.
Meetings will offer a forum for the exchange of views and
information about the industry. The association is setting up
committees to investigate further activities and objectives such
as publicity for microcomputers, professional standards, and
dealer-vendor relationships.
For further information, contact Carl Burlin at (714)956-
7968, or Glenn Dollar at (213) 360-2171.
Page 7
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
17
Is your assembly language program
well structured?
by Webb Simmons
1559 Alcala Place
San Diego, CA 92111
Reprinted with permission from:
COMPUTE Newsletter, Vol 3,#10, pp 18-19
National Semiconductor Corp.
There are a few simple rules that can be applied to your
assembly language program which will show whether your
program satisfies the more important criteria to qualify it
as well structured in the sense of the modem buzz words on
the matter. This presentation is intended to be practical,
whatever that means, rather than theoretical ; therefore, I
can make, and get away with, all sorts of idiotic statements.
The tools you will need are an extra program listing you
can mark up and two colored pens or pencils, say red and
green. These pens will be used to connect program branches,
jumps, skips, and other transfers from the transfer instructions
themselves to the points of reference, the destinations of the
transfers. Here we must make a nice distinction between the
direction of the transfers so thus the two colors, red and green.
A forward reference is defined as a transfer from a lower
counter location to a higher numbered location. And, of
course, a backward reference is just the opposite, a jump or
branch from a high program counter location to a lower
numbered location. But before we start marking, a word must
be said about subroutine jumps. Any subroutine call or sub¬
routine jump that always returns to the point at which called
(to the next executable instruction after the call) need not
be considered to be a branch or transfer for the purposes of
our colored markings. Fundamentally speaking,- a normal
subroutine call is merely a glorified, super macro instruction
more so than a formal transfer of control in the sense that is
important from a well structured standpoint. A subroutine
with an abnormal return upon detected error conditions, etc.,
is not a normal subroutine so the jumps to it and its returns
must be considered as transfers to be marked.
The first step is to use the red pen to mark all backward
references along the side of the program listing from the
jump instruction itself to the place jumped to. It does not
matter but I prefer to make all of my markings on the left
side of the listing. You should be able to draw red connecting
lines from each backward jump to its destination with no need
for one red line to cross another. Regardless of which side of
the listing you choose to draw on, you must consistently use
but one side only, left side or right side but not both sides.
If you cannot draw the red connecting lines for backwards
references without crossing one red line with another, you
are already down the tubes, your program is not well
structured.
After passing the first test of no crossed red lines we are
ready to mark the forward references with green connecting
lines. A green line may cross a red line only if it is outward
bound. If your lines are on the left, a green line can cross a
red line when going to the left but a green line cannot cross
a red line when going to the right. Green lines can cross
other green lines freely, there are no restrictions on green
versus green. Under these conditions you must connect all
forward transfer instructions with green lines to their desti¬
nations. If a green line must cross a red line while inbound,
your program is not well structured.
What do you do if your program fails these tests? Does
your program produce the correct results? Is it efficient in
memory space utilization? Does it execute rapidly? These
factors are interesting, but no matter; you must shoot
yourself!
Since we don’t have multi-colored printing, we are using a
solid line in place of a red line and a broken line in place of
a green line.
PAGE
48
0000
MS=
0
49
0001
LS=
1
50
0000
00
SORT :
HALT
51
0001
02
CCL
52
0002
C400
LDI
0
53
0004
FA01
CAD
LSI2I
54
0006
CA01
ST
LS(2I
55
0008
C400
LDI
0
56
000A
FAOO
CAD
MS(2)
57
OOOC
CAOO
ST
MS(2)
58
. BOTH PARTS NOW TWO’S COMPLEMENTED
59
000E
C400
LDI
0
60
0010
01
XAE
61
0011
03
LOOP :
SCL 4
62
0012
40
LDE
63
0013
F 201
ADD
LS(2)
64
0015
CA01
ST
LSI2)
65
0017
06
CSA
66
0018
940B
JP
NOCRY1
67
001A
C200
LD
MSI2I
68
001C
F400
ADI
0
69
001E
CAOO
ST
MSI2)
70
0020
06
CSA
1
71
0021
D480
ANI
080
72
0023
9C11
JNZ
EXIT- t-i
73
0025
40
NOCRY1:
LDE 4- 1 •
74
0026
F201
ADD
LS (2) i
75
0028
CA01
ST
LSI2)
76
002A
06
CSA
1
77
002B
9410
JP
NOCR Y2-1-1
78
002D
C200
LD
MS(2)
79
002F
F400
ADI
0
80
0031
CAOO
ST
MS(2) 1
81
0033
06
CSA
!
82
0034
9407
JP
NOCRY2 — t -i 1
83
0036
C601
EXIT :
LD
@1(2)4-1 • J
84
0038
40
LDE
85
0039
CAOO
ST
MS(2)
86
003B
9006
JMP
CONT-!--r -
87
003D
40
NOCRY2
LDE -4-i-4-l
i
88
003E
F401
ADI
1
i
89
0040
01
XAE
i
90
0041
90CE
IMP
LOOP
91
0043
00
CONT:
HALT
◄-
J
92
0000
. END
Conclusion: This program is well structured. The only
crossing of the single red (solid) line by a green (broken) line
is outbound, thus O.K.
Note: Lines placed on the right rather than my preferred
left because of more space.
Page 8
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Number 21
18
1
2
3
0001
4
0000
5
0001
6
0002
7
0003
6
0004
9
0005
10
0006
11
0007
12
0008
13
0009
14
0080
15
0010
16
17
18
19
0001
C470
20
0003
35
21
0004
C477
22
0006
36
23
0007
C47A
24
0009
37
25
000A
C46E
26
OOOC
33
27
000D
C400
28
000F
CA02
29
0011
CA03
30
0013
CA08
31
0015
CA09
32
0017
C420
33
34
35
36
0019
01
37
001A
C410
38
001C
CA01
39
40
41
42
001E
C480
43
0020
CAOO
44
0022
C440
45
0024
C980
46
47
48
49
0026
C11E
50
0028
D40F
51
002A
9C5D
52
002C
BAOO
53
002E
9CF6
54
0030
BA01
55
0032
9CE A
56
0034
01
57
0035
1C
58
0036
9CE1
59
0038
C900
60
61
62
63
003A
03
64
003B
C4AA
65
003D
8FOO
66
003F
C202
67
0041
ECOO
68
0043
CA02
69
0045
C203
70
0047
ECOO
71
0049
CA03
72
004 B
cue
73
004 D
D40F
74
004 F
98E9
Number 21
. TITLE'CDB, REFLEX TEST -
. -1
CNTR1-00
CNTR2-01
CNTR3=02
CNTR4=03
DIG4=04
DIG3=05
DIG2=06
DIG1=07
DIG0=08
DIG A=09
COUNT1 -080
COUNT2=010
;START
START: LDI 070 .SET PI
XPAH 1
LDI 077 ; SET P2
XPAH 2
LDI 07A ;SET P3
XPAH 3
LDI 06E
XPAL 3
LDI 0
ST CNTR3I2)
ST CNTR412)
ST DIGOI2)
ST DIGA12)
LDI 020 ; SET FIRST DASH
. DASH
DASH: XAE < -
LDI COUNT2 .SET CNTR 2
ST CNTR2I2)
; LOOP2
LOOP2 LDI COUNT1 : SET CNTR 1
ST CNTR 1(2)
LDI 040 ; FIRST DASH
ST -128(1)
; LOOP
LOOP: LD 01E(1) . GET KYBD <—
ANI OF
JNZ ERROR--
DLDCNTR112) . DEC CNTR 1
JNZ LOOP -
OLD CNTR212) : DEC CNTR 2
JNZ LOOP2 -
XAE ; NEXT DASH
SR
JNZ DASH -
ST (1) ; BLANK DISPLY
75
76
77
CONVERT
78
0051
C203
CONVERT: LD
79
0053
1C
SR
80
0054
1C
SR
81
0055
1C
SR
82
0056
1C
SR
83
0057
01
XAE
84
0058
C380
LD -128(3)
85
005A
CA04
ST DIG4I2)
86
005C
C203
LD CNTR4I2)
87
005E
D40F
ANI OF
88
0060
01
XAE
89
0061
C380
LD -128(3)
90
0063
CA05
ST DIG3I2)
91
0065
C202
LD CNTR3I2)
92
0067
1C
SR
93
0068
1C
SR
94
0069
1C
SR
95
006A
1C
SR
96
006B
01
XAE
97
006C
C380
LD -128(3)
98
006E
CA06
ST DIG2I2)
99
0070
C202
LD CNTR3I2)
100
0072
D40F
ANI OF
101
0074
01
XAE
102
0075
C380
LD -128(3)
103
0077
CA07
ST DIG1I2)
104
105
; DISPLY
106
107
0079
C404
DISPLY: LDI
108
007B
32
XPAL 2
109
007C
C420
LDI 020 ;SET
110
111
; LOOP1
112
113
007 E
01
LOOP1 : XAE
114
007F
C601
LD @1(2)
115
0081
C980
ST -128(1)
116
0083
01
XAE
117
0084
1C
SR
118
0085
9CF7
JNZ LOOP1
119
0087
90F0
JMP DISPLY -
120
121
; ERROR
122
123
0089
C479
ERROR: LDI
124
008 B
CA04
ST DIG412)
125
008D
C450
LDI 050
126
008F
CA05
ST DIG3I2)
127
0091
CA06
ST DIG2I2)
128
0093
CA08
ST DIG0I2)
129
0095
C45C
LDI 05C
130
0097
CA07
ST DIG1(2)
131
0099
C400
LDI 0
132
009B
CA09
ST DIG A (2)
133
009D
90DA
JMP DISPLY -
134
0000
. END
GET MSD -1
GET LSD +1
GET LSD
: SET P2 TO DIG 4
SET TO LEFT DIGIT
; SET ERROR MSG ■<—
OOPS!
; COUNT
COUNT: SCL ; DEC INC CNTR 3 •*
LDI 170 ; DELAY
DLY 0
LD CNTR3I2)
DAI 0
ST CNTR3I2)
LD CNTR4I2)
DAI p
ST CNTR4I2)
LD 01E(1) ;GET KTBD
ANI OF ; MASK 4 MSB
JZ COUNT -
Conclusions: This program is not well structured because
the green (broken) line from line 51 to line 123 must cross
one red (solid) line while inbound (near line 123).
The program would be well structured if the block from
line 107 to line 119 were to be placed after line 133; however
one would have to add the instruction “JMP DISPLY” after
line 103 to replace the normal “FALL THROUGH” from line
103 to line 107. After moving the block the instruction at line
133 will not be needed because it will become a “fall through”
and the red line will go away.
Honesty compels the observation that the program will
work the same after moving the block of code as discussed—
but—it will look better from a “well structured” standpoint.
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 9
19
ISIS: Anatomy of a Real-World
Operating System
by Perry C. Hutchison
Computer Science Department
Iowa State University
Ames, IA 50010
Dear Jim: Received: 77 Dec 23
I am enclosing a sort of “internal logic manual” for Intel’s
ISIS system. This all started some months ago when I became
the victim of a persistent “data CRC” error on the MDS which
could not be reproduced on anything else. Several phone calls
to Intel produced only the claim that, by the time the error
message came out, the information as to what track and sector
were involved was no longer available anywhere in the
machine. This sounded rather preposterous, so I went
a-hunting. About 2 weeks’ work, spread over a considerably
longer period, yielded the discoveries contained in this write¬
up. Since I don’t suppose I am all that unique in needing to
debug things in the context of ISIS, I decided to write it up
for publication. It will probably be fairly interesting to 8080
(and Z-80) hackers, even if they don’t have access to an MDS.
The ISIS disk allocation and directory policies would make
an excellent standard for floppy disk file systems.
This article may also be useful as context for Max
Agoston’s RIMOS (DDJ 9/77).
Very truly yours,
Perry C. Hutchison
ISIS (Intel Systems Implementation Supervisor) is the
floppy disk operating system developed by Intel Corporation
for the Intellec MDS microcomputer system. ISIS was written
entirely in PL/M, a dialect of PL/1 oriented to the 8080 micro¬
processor. The ISIS system is exceptionally well designed; it
bears significant resemblance to Bell Labs’ UNIX operating
system for the PDP-11.
Intel has released neither the source code nor any internal
documentation concerning ISIS. Since a knowledge of the
internal workings of such systems is occasionally needed if
they are to be utilized to the full extent of their capabilities,
a study of the object code was undertaken. This document
contains the principal findings of that study. It should be
useful both as a reference for use by persons having occasion
to deal with the internals of the ISIS system and as an educa¬
tional example of what really goes on in a small single-user
operating system. Names used are taken from the published
ISIS documentation where appropriate.
The information contained herein has been derived from an
examination of the object code of Version 1.2 of 32K ISIS,
received in August, 1976. (The same disk also contains Version
1.1 of ASM80, 1.3 of EDIT, 1.1 of UPM, and 2.0 ofICE80.)
Except where a more general applicability is specifically
stated, this information should not be expected to apply to
any other version of ISIS.
It is probable that, despite thorough checking, some errors
will be found in this presentation. The author would
appreciate being informed of them.
Page 10
Environment
ISIS operates in the Intellec MDS microcomputer system,
and uses the facilities of the MDS Monitor ROM (which
occupies addresses F800H - FFFFH) to communicate with
character-oriented peripheral devices (i.e. everything but the
disk). Table I lists the entry points and functions of the
principal Monitor routines. Parameters and returned values are
handled as in PL/M — see the discussion below. (There are,
of course, additional subroutines in the ROM, but an assembly
listing of the ROM is included with the MDS and anyone
interested in its internal workings can look it up. ISIS uses
no Monitor entry points other than those listed in Table I.)
A detailed description of the MDS disk controller is
contained in the Intel MDS-DOS Hardware Reference Manual
and will be only briefly summarized here. The controller
occupies I/O ports 78H - 7FH, and is controlled principally
by a program-generated “I/O Parameter Block” (IOPB) in
memory. The address of the IOPB is supplied to the controller
by outputting its low and high bytes to output ports 79H and
7AH. The IOPB identifies the drive, the operation to be
performed, the sector count, the track address, the starting
sector address, and the starting memory address for reading
or writing. The disk controller contains a DMA controller
which is used for reading the IOPB as well as for transferring
data.
Organization
ISIS consists of some 57 PL/M procedures, including 8
which merely provide access to the Monitor ROM. The
remaining 49, plus two compiler-generated subroutines, are
listed in Table II; Figures 1 and 2 depict the caller-called
relationships. (Many of the routines of Fig. 1 call one or
more routines of Fig. 2, but the spaghetti effect would render
a combined drawing incomprehensible.) The heavy lines in
Fig. 1 lead to routines which directly correspond to and
implement the various ISIS system calls. (The procedures
ERROR and XEQIOPB are actually Fig. 2 routines, but the
direct calls to them from ISIS are shown in Fig. 1 for com¬
pleteness.)
Table II should be largely self-explanatory, with the
exception of a few abbreviations and notational conventions.
The second column contains the Entry Point address of the
procedure. The columns labeled “T” signify the Type of the
associated quantity: A (Address) denotes a 16-bit value, B
(Byte) an 8-bit value, and L (Logical) a Byte value used in
a True-False sense. (An odd value is taken as True, an even
value as False.) The column labeled “ADDR” is used for
two related purposes: in the case of procedures which have
parameters, it gives the memory address at which each
parameter is stored; in the case of non-parametric procedures
it gives the address at which the first of that procedure’s
local variables is stored. (Local variables of parametric pro¬
cedures are stored immediately following the last parameter.)
A dash in this column signifies that the procedure has no local
variables and, except in the case of the compiler-generated
subroutines, no parameters.
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
20
The combining of ATTRIB and RENAME is a clutter-reducing notational convenience having no special
significance. Both call the same three subroutines.
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
When one procedure is entirely contained within another,
the table entry for the inner procedure immediately follows
that for the outer one and the inner name is indented two
spaces.
Data Structures
One of the principal motivations for this study has been the
desire to obtain information of diagnostic usefulness. To that
end. Table III presents a list of memory addresses whose con¬
tents may assist in diagnosing troubles. In addition, parameter
values in active procedures may be useful. A traceback of
procedure calls is fairly easily obtained from the stack, since
entries other than return addresses are rare. The locations of
the parameters may then be found from Table II.
The central in-memory data structure of ISIS is the File
Structure, located in memory addresses 29E5 through 2B1B
inclusive and summarized in Table IV. The File Structure
consists of 18 tables, each containing 10 entries; each table
has associated with it a “current pointer” which contains the
address of the entry in that table which pertains to the current
file (whose table index may, in turn, be found in 29E5). The
first two entries (numbered 0 and 1) in each table always refer
to the directories of disks 0 and 1; in a sense the directories are
always open, although they do not always have buffers allo¬
cated. Entries 2 and 3 are the console files :CO: and :CI:. This
leaves entries 4 through 9 for the six files which a user
program may have open at any one time. Each open file
corresponds to one entry in each table, but most of these
entries are unused if the file is not on a disk.
The parameter AFT which many of the ISIS procedures
require is simply a number in the range of 0 to 9 identifying
a set of entries in the tables of the File Structure. This differs
from the AFTN supplied by the user (and returned by OPEN)
in that AFT = AFTN + 2.
The I.V. (Initial Value) shown in Table IV is the value
which appears in the particular File Structure member for a
disk file which has just been opened.
Disk Layout
known. Thus the first Linkage block of the directory itself is
always assumed to be Track 1 Block 1, and the Data blocks of
the Allocation Bit Map are assumed to be Track 2 Blocks 2
and 3. The boot ROM expects to find the System Initialization
Program starting at Track 0 Block 1 and occupying as much of
Track 0 as may be needed; the System Initialization Program
then assumes that the first Linkage block of the file ISIS.BIN
(which contains the system proper) will be found at Track 2
Block 4.
Secret “XEQIOPB” System Call
The XEQIOPB system call is not described in the published
ISIS documentation. Its “command” value is 68 decimal
(44 hex); the “parameter block” must contain the following
3 words: 534BH, drive, .iopb (where drive is 0 or 1 and .iopb
is the memory address of the IOPB to be executed). This is
presumably intended to be used by programs like FORMAT
which need to perform disk operations not needed by
“normal” programs. The IOPB is to be set up as if it were to
run on drive 0, regardless of which drive is specified; XEQIOPB
takes care of inserting the drive identification in the proper
places. Normal system handling of disk errors is provided.
Note that this call bypasses all directory accessing, file map¬
ping, and protection flags, and must therefore be used only
with extreme caution. One possible use would be in a program
which does a sector-for-sector copy of a disk. This would be
much faster than FORMAT $A since the normal disk alloca¬
tion mechanism involves considerable overhead. Such a
program could even copy a non-ISIS disk, e.g., DEC RT11,
CP/M, etc., if needed.
Similar calls exist in Version 1.6 of 16K ISIS (the 534BH
entry in the parameter block is not examined, but the drive
and the IOPB address are still taken from the second and third
words) and in Version 2.2 of ISIS-II (the parameter block
contains only the drive and the IOPB adress — the 534BH is
omitted); however since this is an unpublished feature, any
program using it must be considered system-dependent. The
possibility exists that such programs will not work with some
future version of ISIS.
The principles of the ISIS disk organization were rather
well described by David Yulke in the December 1977 issue
of Kilobaud (although he didn’t mention ISIS by name),
but will be included here for completeness and to provide
additional details.
In ISIS, every disk sector falls into one of three groups:
Data blocks, Linkage blocks, and Free blocks; this statement
applies to system data as well as to user files. An ISIS file
sonsists of Linkage blocks and Data blocks. Data blocks
contain the bytes which compose the file, while Linkage
blocks (Yulke calls them Map blocks) tell how the Data
blocks are to be linked together. The first two bytes of a
Linkage block contain the disk address of this file’s preceding
Linkage block (zero if this is the first). All disk addresses
in ISIS are stored as a Block Number and a Track Number.
Tracks are numbered from 0 to 76 and the blocks of each
track are numbered from 1 to 26. The next two bytes contain
the disk address of the following Linkage block. The remaining
124 bytes contain the disk addresses of up to 62 data blocks.
Every ISIS-format disk contains four system files,
collectively referred to as the Format files. These may be
opened for input and read just like any other file, but may
never be written into (except by special system routines).
Tables VI and VII list the Format files and describe their
contents.
The system does not always bother to look the Format
files up in the directory; it assumes that their locations are
Page 12
User-Program Use of ISIS Procedures
A user program may occasionally need to perform a proces¬
sing task similar or identical to that performed by one of the
ISIS procedures. In such a case, it may be desirable to call the
system routine rather than having to write and debug code to
perform the same function. In order to do this, a few details of
the implementation of PL/M must be understood.
Up to two parameters of a procedure are passed in via
registers. (The first thing a parametric procedure does is to
store the appropriate registers into the memory locations
reserved for those parameters.) A procedure having one para¬
meter will expect the parameter to be in the C register (if a
Byte) or in the BC register pair (if an Address). If there are
two or more parameters, the last will be in the E (or DE) and
the next-to-last will be in the C (or BC). The CALLER must
store all other parameters into the proper memory locations
before the procedure is entered. (This sounds messy, and it is.
Newer PL/M compilers pass extra parameters on the stack,
which is much nicer.)
A procedure which returns a Byte value will return it in the
A register; one which returns an Address will return the more-
significant byte in the B register and the less-significant byte
in the A. (Note: this does not apply to the compiler-generated
MPY and DIVIDE routines — see Table II.) Except for such
returned values, the contents of the registers upon return from
a procedure cannot in general be depended upon.
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
22
The benefits of using a system routine must of course be
weighed against the extreme system dependency which results:
the routines will almost certainly be in different places in
different versions of the system and there is no guarantee
that, even after they have been found in a new version, their
results will be the same as before.
Conclusion
Users of the ISIS operating system have heretofore been
hampered by the lack of documentation on its internal opera¬
tion. While such documentation is not necessary most of the
time, the need for it occasionally becomes critical. This presen¬
tation should partially fill that need for Intel customers while
also assisting hobbyists in understanding how a first-rate
operating system and file handler is organized.
CP/M USERS’ GROUP
Dear Jim: Received: 77 Dec 16
Just a note to inform you that there exists a CP/M Users’
Group which is active both in user software exchange and also
in group purchasing of proprietary software. Although desig¬
nated CP/M Users’ Group, we also naturally welcome users of
IMSAI DOS-A and M-DOS and of the Cromemco CDOS, and
soon expect to see a TDL FDOS which is similarly compatible
with CP/M in terms of program load point, DOS call conven¬
tion and diskette allocation and directory format.
Kindest regards, 345 E 86 Street
Anthony R. Gold New York, Ny 10028
NORTH STAR EXECUTIVE SOFTWARE
News Release Received: 77 Sept 13
XEK, a complete system executive package for North Star
users, is now available from the Byte Shop of Westminster.
The XEK package contains a disassembler capable of
creating files that may be left in memory when changing from
the disassembler to the executive package for re-assembly.
The monitor software has the ability to accept input from
cassette tapes and paper tape as either source or object files,
as well as from the North Star diskette system. In addition,
the assembler features a new auto-line editor for the creation
of source files. This editor also extends to the modification of
existing object files.
Another feature is the XEK’s ability to handle up to six
named files at once that may be consecutively assembled to
form one object file. The assembler, monitor, and disassembler
come with complete documentation, both on disk and as a
manual. Total price, including first class postage, insurance
and California resident’s sales tax, is $48.00. For further
information and ordering, contact: The Byte Shop of West¬
minster, 14300 Beach Boulevard, Westminster, CA 92683,
(714) 894-9131.
rt <->
M 3
«5 a
x g
t/i Q>
C -h
^ O
3 52
♦J G
Q> O
co. u
V)
*-> +J
3 3
CX CX
*-> *-»
3 3
2 u
8- *-»
O
«/>
G ^
cl
3 X
*-> o
a>
CC nJ
f-i o
U 4-»
3 X
U X
Vi -h
G O
u u
3 ♦-»
*-* G
a> o
a; u
w to
g a
o s
oort
a d,s:
17) •
4-* O
3 O
CX-H
«-» >
g .s
tc M
•H T3
X T3
rt
«/>
£ f?
3 O
>
17) O
c T3
a"
> 4J nJ
to
H
<
H
tO
UJ
H
>-
H
3
O
Q >-
t—t CC
§£
O. UJ
UJ
p
H
3
O
H
CO
U
a
i
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
23
future
Table II. Internal ISIS Procedures name- e.p. parameter t addr returns t purpose. calls
C O O H
= O' < f.
uc wa
w uj c: >
h
< u. ^ u
u d u t- u u
OCQQ W< UW
JCUh Nh
j j w q > m a:
<uu kq: w 2
U 3 CX CX rt
O O O CJ O O
3 U 3 E 5 E
OS -J
UJ <
it fee
HDDU
U. CQ O <
< • U •
tu O r« -t o
o a a q a
u u u u u
<N (N rvi rvi rj
UJ <3
£££§
HD D U<
U. ffl o <U
< • u • 2
3 Q CO UJ U
co ^ c. < u u u
uj o*~<<u:Hu:l; 1 -co
Ul>-<2^UHN2Hh
c£Ouu:uj^uiuj>-<>-cs;ci
u c: z
CO O U. 2 ;
O KH w
-J es u; a.
U UJ u o
< o u.
X 2 OS H
a. 2 cs uj
5 : cs uj o
= CO
U D cc
aiiHu<
ou.
c: H c<H
u u u uj u
UJ o to to to
—• O
C C 3 O
O 3 *J O
•h to a
U* 3 3 to
3 U to
U *“ H O
U E a> H
X O *J ~3
a> 4-» c -o
to -H «
to X
o <o td u
UD P u
o v c a
H ^ a> >
2 c uj uj
fl> to cx
& to < UJ
n h 2r
C cx -3
•H O O 4-»
D U U rl
to
to -h a> qc
H 3 C
^ U 0* H
O to o *->
> < u u
c» cr* di
or 31 or
fN CM (M CM
31 < UJ
U) UJ 31
u u a
cm cm cm
OS H
UJ uj »-•
CQ UJ OS O
A to UJ H
3 < = a
2 cas Z
CQ
CO
J
O'
2
<
J
o
UJ
u
u
Q
Page 14
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
24
NAME- E.P. PARAMETER T ADDR RETURNS T PURPOSE. CALLS— NAME- E.P. PARAMETER T ADDR RETURNS T PURPOSE.. CALLS—
> ea
cc: uj <
C Q H
cc o H H
h c: h huj uj
cj uj u. cc co c/)
— CQ
e:zu< uj
O U. cC H U H
cc H < H g ^
CC UJ UJ UJ >- CC
W U W w w 2
u CO CQ
O CQ O.
-3 C. < UJ O
J < u: t- H *-•
<2. lu E— h o'
uj 3c UJ UJ CC UJ
o CC w W > X
CQ O 2 <
uj cc c wu: u
UJHX<ZUJH
cj uj a. uj uj uj uj
u. (dt. cc c:w w
CJ
H *H
a u.
(/) u. «.
o =) c
£ta o
5 -H
C +-» •
Sh -H .H ft)
f O 1/1 t-H
Jut VI o JQ
^■h am
J3 W U-H
v> a) rt
V» O s >
0) U O eft
H
w ,* ft) •
■o u au
rt O O —i
ft) H M -r4
cc x> a 4-.
e -h ^ <d
o 4-* o x:
u c o
4J 3 T3 rt
0) ft)
Ifl C -H ^
U UJ 4-.
ft) U. tf) V)
*-> U_ -H -H
U D
Cl CQ eft 0 )
f>l t/l f-H
CJ O -H
x: u) v) 4 -t
O C -H I
•H 4 -t
V) Ho
U D 2 I
« -< 2 T3
ft) o C
esc 4 h cj a>
-a c
ft) -H
o i e
u* ft) C •
X C -H ft)
X) -H w c
I H ft) -H
C 4t£ C
O *■» ft)
ft) U
JZ u o u
J ft) J 3
V) u» o
O CTJ U>
U) o O •
ft) O 1) <
•-* —< f-< -S’
ft) »-h -H Q
O eft -3 <N
Q UJ O CM
Q Q UJ UJ
cj u u u
CM CM CM fN
UJ <
u- H ^
. U- Z H
h3 D U
U. CQ O <
< • u •
CQ
Z CL
O UJ O Z
h UJO f- , K, <2 OUJOZ UJ CJ X CC
CnnWWhOHQSJQ<U^UhHUJ COOUZUJQ
uczjHCH<uj<z^ujOHcya. ocj*uju<
(-JOWQCxOauJUJujujrciujo j c: w cl < u
CUUOujuJujJoaJaJo'inSSxc^ uwz o o-e:
<u- Hu. a u = ca cj
UD CiHtOU.D22CLhU< ui UJ
O CC O UJ UJ <CQlLM<<c:UUh w
J CJ cJ uj uj HhH3:^c:<hi: Hh
—J j DC CC CC UJ UJ UJ UJ 2: CJ UJ U)>- cc cc
<CJ UU.U. UOU cCcCW W WW X *2
■o 3 /-N C ‘
ft) O UJ ft) T3
u* U C. > C
rt w -h eft •
u C be
ft) O « V)
C -H ft) C
ft) u» *-h be ’
be Cft CJ -H *H
i u cq U-t in ■
U *H N-' V)
ft) eft eft
-« H N
•H -H V) ••
CLu» ^ C ft)
E UJ ft) E
0 3 0 a, eft
V B (DC
H l/l UJ
f-i w
V) ft) rH
ft) 4 h UJ
ft) 4 -t UJ
U 3 CC
U. 3 U.
00 < CJ UJ
Ul UJ UJ UJ
Q Q Q Q
CM CM fN tN
Z H
UJ 2 CC
U. Uj UJ
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
25
name- e.p. parameter t addr returns t purpose. calls— Table III. ISIS Variables of Diagnostic Significance
"2 i e
rt rt
o g
$ 8.
E
3 4)
O *-»
UJ
3 G
G O
a a
to
to
£
a
a
a
rsi
i
U
s
5 '3
H
G.2
rt
r-H 4)
rt *-*
u uj
•H C
tC. -H
u c
♦-* o
•H 5!
X) 4>
4) X
Q 4-»
Cl *H iH
x n
ec H 4-»
G UJ
0 0—4
-« X O
3 O a
h h y
rt O O
> M
*J E 4> rt
>9 9
u ifl Ifl
X 4>
= UJ uj
UJ 3
Jui rt
a o
o
— to *j
u oi
= U 5
x ^
T3 'o' • O
O H H W
*-» .Q rt rt
rt rt 3 uj
G G G UJ
O Cl i« (I
c > s: e
O o
oc u o r
41 k t
r g rt cm
4) I 2
GC 3 G
X O G O
H C rt o£
’ — cc
♦J UJ
h: w:
3-3 0
UJ G Q 4)
u eg i x
cc x to *j
r : a
Z 4h
”3 rt ' O
G O
3 X X *-»
4-» G G
cc o rt
•H •
4-» G U) 3
—• O 4>
3 4) -H *j
w C il C
41 C U -H
— O 4) G
- 0 3 3*
G X
o o
4* rt
3 O 4-<
4) 3 .
*-• G X
a* g
e 2 «
4) C.
G. C
! 4> E
> rt c
« G. O G
. tO O h
G G O »-t
4> 4)
4-t tM
4-4 IM
55
4> 00 —<
£2
g o,
X X
CO H
o 3
CO CQ
CO CS|
“ o
y s
< rt
G U
X-h
X u.
X 0 O
G O a
X 3 CM
M C I
3 h a
I 4)
X
s. a - *
X) G O
• O X
CM Cm G
uj
u o
H l/| !0 w
<4 C S3 X
G -H (N 4)
G rt l
fl> U N 4>
*J G o° E
coon
•-t t» cm G
O
S
H
G 5
5 £
* c.
zr uj
O 4)
CG G
<
UJ X
to G
(?3
cb'
3 & 3
CX5 G
o uj
X nJ
&,a
rt o
UDK7. UZt<UUJ
OCQOUlUH<UUJy)
jkc:u.w JZhNH
88
as
CG
1
C£
UJ
0 0 4)
G. G —-«
OX;-*
CC X *G
3 W h
a: -h
H 3 4-1
4)
UJ G 4>
C to oc
G O G
3 3 rt
CC X
C r-.
t-4 G
z o
g.
in o
- G
UJ
a g •
3 4> uj
G 4)
UJ C H
4-» -h a
o o «
to G. G
rt h
5.5
•H .*
^ o
5 O
«j O
4-»
CC UJ
UJ 4>
ZD o
a u
O 4) r
•h 4i m
G.E C
o rt o
U G U
4)
4J •
u e:
rt uj
G U.
rt u.
x a
U CO
H E
2 O
a g
o 4-1
O
G.
O 4-.
*-* E >
-H o *H
G G G
> O. UJ 3
•H O 4) c
G 3 rt
G. 3 O
G- h G,<
3 O rt O'
m G > c
I 4-J c <
GN h o rt 1
X G UJ 4-»
o o m
4) 4-* O 3 •-4
3 G 3 C -4
•—« -h o rt
rt uj G. o
> C -H UJ
se
o *
G O
G -H
O
u 44
a uj o cm
CM <N to PO
a a a a
CM CM CM CM
rf o oo a
3 3 3 3
a a a a
CM CM fN CM
UJUJ
aa
CM CM
CM CM
CQ CQ
CM CM
3 tO vO 00
tO tO to tO
CQ CO CQ CQ
CM CM cm (NJ
UJ O h
H a a x
U* Q CQ CQ
<5 • •
Si
D^ZZ
a a x x
a a cq a
Ha
Uj a
H a
u. a
< •
UJ CQ
CC
a u uj
Q a uj uu
o > lo a
■jn x a
d. c: ^ a
o a {— .
a
H
a
a
<
H
s
cy
a
x
o
t-4
X
Page 16
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
26
addresses contents.-.-.—.-. Table V. ISIS Device Identification Codes
hmqhohh q:q: hm a a. .
CQ OHNNl-tlOvOMOOlOHOJ (O Tt 1/1 <5 N
UJ
b *-*
Z tO
C/5
UJ
C/5 I
C/5 •
UJ I
ci <
a H
9<
O
I H f-l
X5
S;
z
g 3
C/5 C/5
s §
a
w
b
o
Q
00
00
U. _ M HH
-O
CC3
H
o
to
3 U
U« *J
o a>
> ~t
a> a>
c "3
C X ^
*-• V5 X I
E
3
2
efl
K
H
8 8
to oc
to ca
a> jc
m c
x,
UJ
w O
la
be to
o c
r-t U*
3
b
o
E
O
s
£
2
x
o
3
u»
■*—>
C/3
cz
2
H
X
cu
o
UJ
^ o>
(J M
O
—t *-»
J3 rt
I
.* ♦-»
to C
o o
U U
D 10
3 H
E— *-»
rt
4->
c3
•3
O -H
2 o
H E
O
•
0) o
J3 —<
sa
C/5
t •
J«C Jrf
o o
c3 O
u ^
t— J3
2 5
*-»*-» O
*3 Q 9
2g3
c
o
CJ
O)
33
U-
C /3
eccc
8fc
s a s
«
a
a a a a a
3
a
<
o
a
8
a
X5
cd
H
3 2
CJ
a
i
Q£
E
UJ
I
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 17
27
The SAM 76
by Ancelme Roichel
copyright 1977
Pennington New Jersey, U.S.A.
All Rights Reserved
Language
(T
U
U
U
U
U
{}
1)
U
0
U
n
n
This text was formatted from a raw text file {}
employing procedures which make use of the {)
U
<ncra> 21 {)
0
SAM76 language processor {}
{)
{}
_II
Typographical and code assignment table
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0
0
0
0
1
1
1
1
2
2
2
2
3
3
3
3
0
2
4
6
0
2
4
6
0
2
4
6
0
2
4
6
0
00
0
@
P
•
P
0
@
P
'
P
1
01
i
1
A
Q
a
q
;
1
A
0
a
a
2
02
11
2
B
R
b
r
"
2
B
R
b
r
3
03
It
3
C
S
c
s
It
3
C
S
c
s
4
04
$
4
D
T
d
t
$
4
D
T
d
t
5
05
%
5
E
U
e
u
%
5
E
U
e
u
6
06
&
6
F
V
f
v
&
6
F
V
f
V
7
07
1
7
G
w
g
w
1
7
G
w
g
w
8
10
(
8
H
X
h
X
(
8
H
X
h
X
9
11
)
9
I
Y
i
y
)
9
I
Y
i
y
A
12
*
:
J
Z
j
z
*
:
J
Z
j
z
B
13
+
t
K
(
k
{
+
f
K
[
k
{
C
14
t
<
L
\
1
1
f
<
L
\
1
1
D
15
-
=
M
}
m
}
-
=
M
]
m
}
E
16
.
>
N
“
n
~
.
>
N
“
n
~
F
17
/
7>
0
o
/
?
0
o
The SAM 76 Language
The SAM76 language combines into a single interpretive
processor characteristics of two different string and
general purpose macro generators and one (or more) infix
operator mathematical systems.
SAM76 was primarily inspired by the "M6 MACRO PROCESSOR"
designed by M. D. Me Ilroy and R. Morris of the Bell
Telephone Laboratories. A description authored by Andrew D.
Hall is given in the Bell Lab. Computing Science Technical
Report #2, and other places.
The second source of inspiration came from the syntax of
"GPM - a GENERAL PURPOSE MACRO GENERATOR" described by its
author - C. Strachey.
GPM syntax very significantly improves the interface
between the user and the language by eliminating an
awkwardness inherent in the design of M6. This awkwardness
arises out of the fact that in the M6 language the
specification for the action to be performed on the result
of an expression evaluation is at the right hand end of the
expression to be evaluated; this requirement causes the
need for a unique pair of characters to be designated for
the purposes of "quotation"; consequently when the writer
of procedures in M6 is terminating the writing of an
expression he must mentally reconstruct the sequence of
alternations of "quoted", "active" and "neutral"
expressions which may be nested one within the other.
In GPM, where the nature of the expression is specified at
the left end, only one character need be identified to
serve to provide the right hand boundary for all three
types.
Ibis means that the user, when closing out his writings,
need only supply enough such identical characters (plus a
few for good measure) to enable correct action to
subsequently take place.
An universal lament of users of both M6 and GPM relates to
the extremely unnatural method in which arithmetic
expressions must be organized. The simplest arithmetic
expression in normal "infix" notation becomes a tortuous
involved nest of strange symbols when expressed in either
M6 or GPM. A simple solution exists, is incorporated in
SAM76 and forms the third element of the language.
In addition inspiration for the selection and design of a
number of the resident functions came from a variety of
sources (see reference list).
Acknowledgement is made of the contribution made by L.
Peter Deutsch [U.C. Berkeley] who conceived of nesting an
expression calling for input inside an expression which
causes output [Ref. 3] thus:
{OUTPUT,{INPUT}}
Finally acknowlegement and great appreciation is expressed
for:
The help received from Neil Colvin [M.I.T.] who provided me
with an 8080 simulator for the PDP-10 and who coded a
preliminary version of the language to run in an 8080 based
microprocessor system contributed also materially to the
development of this language.
Page 18
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Number 21
28
Barry Lubowsky [Rider College] who allowed me to make use
of a PDP-10 and who was most helpful with some system
software problems.
Roger Amidon [Delta Data Systems], whose actual 8080 based
"ALTAIR" and "IMSAI" microcomputers were used to test and
debug the software, was also most helpful in developing a
family of "people" oriented mnemonics and functions
particularly well suited for the "amateur" user.
Other people who contributed to various details and who
"people" tested the language are Carl Galletti [T.D.L.],
Marty Nichols [Newsweek], and Tom Kirk [N.J. Bell].
References
1. Strachey, C. - "A general purpose macrogenerator".
Computer Journal, Vol.
1196510001.
8, No.
3, Oct. 1965 p.
225;
2. Hall, Andrew D.
- "The
M6 macroprocessor",
Bell
Telephone Labs; Computer Science Report No. 2; 1971;
3. Kagan, Claude A. R. - "A string language Processor for
small machines", Proceedings of the ACM SIGPLAN Symposium
on the Pedagogical Applications of small Computers,
University of Kansas, Lawrence, Kansas 1197111181.
II II This description of the SAM76 language
I I Notice 11 is substantially the same that is
IJ_JJ available from the IEEE Computer Society
Repository, R 76-301 - August 1976.
The three elements of SAM76
The first element is designed around the 11
characteristics described by STRACHEY in 11 GPM - S76 11
his GPM (General Purpose Macro Generator) IJ_[I
language.
Strachey defined its general forms as follows:
Active %function,arguments, . :
Neutral %VAL,function,arguments, . . . :
In order to avoid ambiguity and to provide consistency the
above is changed for the purposes of SAM76 as follows:
Active %function,arguments, . /
Neutral ^function,arguments, . /
Protected ! . . . protected string . . . /
In addition changes and extensions are made to the language
originally described by Strachey. The modified form
incorporated in SAM76 is to be known as S76; this is a
fully operational proper subset of SAM76.
The syntax used in connection with the S76 system is to be
referred to as the "S" syntax of SAM 76.
The second element is substantially as 11
described by Andy HALL for the M6 II M6 - M76 I I
language attributed to Me ILRDY and IJ_[I
MORRIS:
Active ((function, arguments,.:
Neutral #function,arguments, . ;
Except for different function mnemonics no change was made
in the syntax and notation of M6 for the purposes of SAM76.
Number 21 Dr. Dobb's Journal of Computer Calisthenics
In consequence routines and texts written for M6 processors
distributed by the Bell Labs outside the Bell System should
be compatible with SAM76.
Compatibility with M6 is insured by enabling user to
stipulate whether "resident" or "user defined" functions
are to be first searched whenever an expression is to be
evaluated.
Expressions written using the M76 syntax will first cause a
search of the user defined functions; if no user defined
function of that name exists then a search is made of the
resident functions. Expressions written using the S76
syntax will first search the resident functions.
Although there is syntactic compatibility with M6, the
implementation in SAM76 is designated M76 because of the
generally different complement of resident functions, and
the significant enhancement of the scan algorithm.
Hie syntactic form of expressions based on the M76 system
is to be referred to as the "M" syntax.
An infix operator system characterized in I I II
general by the following example for a 11 A76 11
simple arithmetic expression: IJ_j|
Example [ 5 + 5 * (144/12) ]
Hie syntax of the foregoing system is to be referred to as
the "A" syntax. Hie evaluation rules and internal syntax
may vary between systems for this sub system; a method of
identification is provided within the framework of SAM76.
Input - Activating - Scanning and Output
I I The flow of characters, be they
I I Input and 11 procedures (programs) or just plain text
I I Output 11 between the SAM76 processor and either
IJ_[I the user or other sources or destinations
is under the control of two resident
SAM76 functions:
Input from user (or source) to SAM76 is under control of
the "input string" function whose mnemonics are "IS"; this
may be used in either the "S" or "M" syntax either as an
active or neutral function thus:
type
active
neutral
S76
%IS/ or
&IS/
M76
#IS: or
IIS;
Output from the SAM76 processor to the user (or other
destination) is controlled by the resident "output string"
function, mnemonic of which is "OS"; active or neutral use
in both the "S"
1 and "M"
syntax
is:
type
active
neutral
S76
%OS/
or
SOS/
M76
#05:
or
IOS;
Initially and
whenever
its task has been
II
completed,
the
5AM76
processor
1 1
Hie
automatically
loads
a
"restart"
II
"restart"
expression which is scanned and
provides
II
expression
the means for accepting input and
delivering output; this expression is
initially defined as the S76 expression:
&os,%is//=
Orthodontia, Box E, Menlo Park, CA 94025 Page 19
29
The initial or standardized condition
makes use of the equal sign "=" to
ACTIVATE the processor; this "activating"
character may be changed by the user
through execution of the appropriate
SAM76 resident function.
I Activating
I the
I processor
I_
II II When expressions are nested one within
II Scanning II the other, the SAM76 processor first
IJ_[I executes the innermost, proceeding from
left to right.
Hie innermost in the "restart" expression is:
%is/
and therefore input is sought; the user input is terminated
with an activating character, the (=) will be shown to
remind the user how to terminate his input.
Once the input is terminated, it is in turn examined by the
scanner for possible further execution until finally the
outermost expression of the "restart" expression is
encountered:
&os, ... /
where the series of periods represents the result of
processing the user input and in fact will be the output
that is to be given the user.
i| Quoting or Protection
Frequently the user may wish to incorporate in his text
certain characters which have special meaning to the
scanning system of SAM76. Typical of these are the
characters used to indicate the start and end of
expressions. These are known as "warning characters".
For standardization purposes a processor for the SAM76
language is initialized with the following assignment of
"warning characters":
Abbv.
Char.
Octal
Purpose
SA
%
45
Begin S76 active expression
SN
&
43
Begin S76 neutral expression
SP
1
41
Begin S76 protected string
SE
/
52
End S76 expr. or protected string
MB
#
43
Begin M76 expression
MA
:
72
End M76 active expression
MN
1
73
End M76 neutral expression
AS
r
77
Argument separator
QC
@
100
Quote single character
BQ
<
74
Begin quoted string - Pair 1
EQ
>
76
End quoted string - Pair 1
BP
(
50
Begin protected string - Pair 2
EP
)
51
End protected string - Pair 2
BA
[
133
Begin "A - syntax" expression
EA
1
135
End "A - syntax" expression
Strings of symbols found between the above illustrated
enclosures are said to be "quoted" or “protected" and are
completely ignored during the scanning process.
The two rules that follow are applied to the scanning
process with respect to the use of "quoting characters".
I I When an unprotected character designated as a
II 2 II "quoting character" is encountered in the left
IJ_[I to right scan of an expression, the other
character of the pair is then defined as the
character which will end the quoted string; this means that
for the two initially designated pairs shown above, quoting
or protection may also be achieved as follows:
>....< or ) .... (
ll Tl In the process of finding the character which
II 1 II is to terminate a particular quoted string any
IJ_[I occurrence of the same character as that which
identified the beginning of that quoted string
must be balanced by a corresponding "end of quoted string"
character.
This is to be differentiated from the action which takes
place in connection with the "protected string" of the "S"
syntactic form:
! . . . protected string . . . /
In the foregoing a tally is made of "unquoted" warning
characters in order to find the slant sign "/■ which
matches the exclamation mark:
The tally count is increased by a count of one - % & ! #
The tally count is decreased by a count of one - / : ;
It should, however, be noted that the "warning characters"
(symbols used to delineate bounds of expressions) shown in
the foregoing illustrations and examples are changeable by
the user and are only representative of initial or
standardized conditions.
Any of the foregoing "warning characters" may be changed
using the appropriate SAM76 resident function; the
abbreviations listed earlier are used to identify the
particular warning character it is desired to change.
When an unprotected "character quoting
symbol" is encountered, then the
immediately following character is
considered to be quoted. This is
particularly useful when the user wishes
to quote single characters, such a
warning character, without having to
maintain a balance of quoting character pairs.
Initially the "character quoting symbol" is set to be the
"coninercial at" ( @ ).
I Quoting or |I
I protecting 11
I a single I|
I character I I
Using the SAM76 syntax, functions, and trace ii
In both the "S" and "M" forms of SAM76,
the equivalent of string quotes may be
provided by any pair of characters
designated for that purpose. Initially
two such pairs are defined and consist of
the following balanced pairs of
enclosures:
In the examples that follow the I ... I arrangement is used
only to delineate output at the user terminal; if for
instance the user wished to add two numbers making use of
the "A" syntactic form, the following might be observed:
[5+5 ]=|10|
I
I Quoting or
I protecting
I a string
<....> or ( .... )
Page 20 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 21
30
Define Text with id number
IT T| In the following example the M76 syntax
I|M76 example I I is used to create a "macro" which when
|J_|| invoked will square any desired number:
♦DT,SQ,<#MU,ql,ql;>i- DT means Define Text
MU means Multiply
SQ is name given to text
#PT,SQ,ql:= PT means Partition Text
There are four possible actions which may ensue when the
macro, or user defined function named SQ is to be invoked:
|DT,t,s,dl|
This function places in the "text area" the string denoted
by "s" in the expression shown above; this text is given
the name denoted by "t". An arbitrary identification
decimal number denoted by "dl" may also be included as part
of the "text" record. Previously defined text with same
name is erased and replaced with this definition.
Examples:
1. #SQ,5:=|25|
2. #FT,SQ,5:=1251
value returned is 25
M76 #DT,NAME,THE SKY IS BLUE:
FT - Fetch Text, value 25
S76 %DT,NAME,THE SKY IS BLUE/
3. #SQ,5;=1251 value returned is 25
4. #FT,SQ,5;I#MU,5,5:I value is Text of SQ
In the foregoing examples no id. number was desired, and
consequently the default value of zero is stored as part of
the record created by this function.
IT TI The foregoing example is repeated below
I IS76 example |I making use of the S76 syntax; however to
|J_[I illustrate its use, the infix system is
used for the actual multiply function:
%DT,SQ,![ql * ql]//= ql is dummy variable
%PT,SQ,ql/= ql becomes partition valu
e
1
The four invocations of SQ are shown below:
1.
%SQ,5/=|251
value
is
25
2.
%FT,SQ,5/=1251
value
is
again 25
3.
&SQ,5/=1251
value
is
still 25
4.
&FT,SQ,5/=I( 5*5]l
value
is
now "text" of SQ
I I In general the mnemonics used in SAM76 to
I I Resident I I identify the resident functions are
I I Functions I I composed of two alphabetic characters.
IJ_[I This is not a restriction imposed on the
language, and three or more alphabetic
characters may be used to identify resident functions. In
fact the user may wish to employ the "@F" ("wh@" (what)
Functions) mnemonic to ascertain the mnemonics in actual
being in his system.
It should be remembered that when the sign serves the
purpose of "quoting single character" then the expression
to list the resident functions would be:
M76 l@@F, ... :
S76 %@@F, ... /
where " ... " is the string of characters which will
precede each resident function name in the result of
executing this expression.
Descriptions of the functions and examples in which either
S76 or M76 syntax is applicable employ the I (Long Vertical
Mark) character to bound the expression. In actual use the
I is replaced by the appropriate pair of warning
characters.
In the case of "null" valued functions where the neutral
form of the expression is to be illustrated, the \
"reverse slash" is used in lieu of the I.
Texts in the "text area" may be examined
without evaluation using the "vt"
function. This examination will display
location and value of any "partitions",
"multi-partitions", and the text
divider(s) when at a location other than
the head (or extreme left) end of the text
II
1 1
The "VT"
II
II
1 1
View Text
II
II
1 1
function
II
II
Initial conventions for the display within a "text" of
partitions, multi-partitions and text divider(s) are:
[1], [2], ... (d)
Partitions
[#1], (#2), ... [#d]
Multi-partitions
n
Text Divider
When in the "Trace" condition, active II Tl
expression about to be evaluated will be I I Trace 11
shown bounded by the I, neutral IJ_[I
expression by \, regardless of the syntax
(M or S) of the expression.
IT-
I I "id"
I I numbers
II
Tl
11
11
II
The M6 language provides a unique
identification number for each of the
resident functions of the language, and
means for the user to assign a similar
type of number to defined functions. This
numbering concept is preserved in SAM76; numbers between 1
and 99 inclusive are not assigned to any resident SAM76
function unless its name and operation is absolutely
identical to its M6 counterpart. This permits user defined
functions to be written to mimic M6 functions if desired. A
list of M6 functions and their assigned "id" numbers is
given in an appendix.
To illustrate, the M6 function "DEF"
might be mimicked in the SAM76 system as
II
1 1
User
1 1
II
follows:
II
defined
II
la. %DT,DEF, !%NI,<&>,<%>/DTtnpl</>//
II
1 1
function
II
II
2. %MP,DEF,mpl/
examination of the defined text (or function) DEF can be
made using the SAM76 "VT - View Text" resident function
thus:
3. %VT,DEF/= | %NI ,<&> ,<%>/DT(#l] </> I
The formal description of the "DT" - "Define Text" function
is given below to illustrate the manner of presenting SAM76
resident functions.
in the foregoing ”mpl" is a dummy for a "multi-partition"
which will be created by the second expression and
visualized by the VT function as [#1].
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 21
31
The function "NI - Neutral Implied" is used to provide the
expression using DT with either the active or neutral
warning character as used with an expression containing
"DEF" as its operative argument.
Alternatively expression (la) could have been written in
one of the following ways,with exactly the same end effect:
lb. %DT,DEF,<%NI,@&,@%/DTtnpV>/
lc. #DT,DEF,<#NI,@%:OTnpl/>:
l d. #DT,DEF,<#DTtnpl%NI,@:,@:/>:
le. #DT,DEF,<#DTmpl#NI,<;>,<:>:>:
Algorithms in the SAM 76 Language
Tl
II
II
ll TI In the algorithms described and
I I introduction II illustrated in this section, use is made
|J_U of the procedure named "print" to
display the script of the functions,
expressions, and other text strings.
The "print" function is useful in that it augments the
capability of the "vt - view text" function by prefixing
each individual "text" displayed with its name bounded by
angle brackets; assuming that texts have been created as
shown:
tr.—-.
{} %dt,a,apple/=
0 %dt,b,bottle/=
{} %pt,b,t/=
{}
The use of "print" would cause the following display:
< a >
apple
< b >
bo[l][1]le
The need and use of the "print" ll Tl
expression was described earlier; the 11 print jI
expression to accomplish this task uses |J_[I
a multi partition value #2.
Typical use to print out name and contents of the text area
which in this example only contains the "print" expression
would be:
Tl.-.
{} *print%lt,(,)//=
{) < print >
{} %ii,[1],,,!os,
{} « [1] »/%vt,[l]/*os,
{} /Iprint[#2]///
{)
A simple way of doing some procedure 11 Tl
"proc" some desired "n" number of times 11 do "n" Times I I
is exemplified by the use of "ds - IJ_[I
duplicate string" in the expression
named "dnt":
< dnt >
%ds,[1],!%proc///
The simple recursive function named ll Tl
"fac" generates the factorial of any 11 factorial 11
number which replaces partition value 1 1 1 _[I
in its use.
< fac >
%ig,l,[1],1,!%mu,[1],%fac,%su,[1],1/////
TT..
{) %fac,5/=120
U
This recursive function named "exp" is 11
used to generate the exponential of "m" 11 exponential 11
to the "n"th. power; in use "m" replaces IJ_[I
partition value 1, and "n" partition
value 2.
< exp >
%ig,[2],,!%mu,[1],%exp,[1],%su,(2),1////,1/
n.
{} %exp,3,7/=2187
U
The recursive expression named "mrn"
extracts the "m"th. root of any number
“n"; it should be noted that this
function makes use of the expression
named "exp", which generates an
exponential.
II II
I I "m"th. I I
I | root of "n" I I
< mrn >
%ig,%exp,[3],[2]/,[1],
!%su,[3],l//,
!%mrn,(1],[2],%ad,[3],1////
TT.
0 %mrn,2187,7/=3
{}
Expression named "tensor" is used to ll Tl
generate a list of successive numbers 11 tensor 11
separated by the size of the list IJ_H
is specified by the integer number which
replaces partition value 1 in the expression.
< tensor >
%ig,[1],l,!%tensor,%su,[1],1//.[1]/,1/
A frequently needed capability is that
of generating "roman" numbers, as for
text section and chapter headings; when
function "dtr" is invoked with a decimal
number as its argument, the value
returned is the same in roman notation.
Thanks are extended to Jim Gimpel, of the Bell Telephone
Laboratories for suggesting this as a most useful adjunct
to the SAM76 language, as it is to the SNOBOL language.
1
1
Decimal
"Tl
II
1
to
II
1
1
Roman
II
II
Page 22 Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia. Box E, Menlo Park, CA 94025
Number 21
32
<; atr >
%dt,x, [l]/%roml/%y/%et,x,y,z/
< roml >
%ig,%crd,x/,,!%rom2,*fc,x//%roml///
< rom2 >
%dt,z,[l]/%pt,z%d//*dt,z,%z% r///%pt,y*u//*dt,y,%y% t//% z//
< d >
,0,1,2,3,4,5,6,7,8,9
< r >
,,I,II,III,IV,V,VI,VII,VIII,IX
< u >
,I,V,X,L,C,D,M
< t >
,X,L,C,D,M,*,§
< hanoi >
%ii,[1),0,,!%hanoi,%su,[1],1/,[2],[4],[3]/!
Move Ring [1] from [2] to [3]/
%hanoi,%su,[l],l/,[4],[3],[2]///
Given the need to move four rings from "hither" 4^®-yon",
using "thither" as a way station, the monks needed only to
follow the following sequence to do the task in a minimum
length of time:
tr.
{} %hanoi,4,hither,thither,yon/=
(}
Move
Ring
1
from
hither
to yon
{}
Move
Ring
2
from
hither
to thither
u
Move
Ring
1
from
yon to
thither
{}
Move
Ring
3
from
hither
to yon
{}
Move
Ring
1
from
thither
■ to hither
{}
Move
Ring
2
from
thither
to yon
{}
Move
Ring
1
from
hither
to yon
{}
Move
Ring
4
from
hither
to thither
{}
Move
Ring
1
from
yon to
thither
{}
Move
Ring
2
from
yon to hither
{)
Move
Ring
1
from
thither
■ to hither
{}
Move
Ring
3
from
yon to
thither
(}
Move
Ring
1
from
hither
to yon
(}
Move
Ring
2
from
hither
to thither
{}
Move
Ring
1
from
yon to
thither
{}
The “hex" freak can fulfill his desires
by defining the "htr" expression to
achieve "hex to roman" conversion:
II II
I I hex to roman I I
II II
< htr >
%dtr,%xd,[1]//
The user often finds it necessary to I I
derive a series of answers resulting 11 loop
from the execution of some script for a IJ_[I
range of numbers "nl" to "n2"; the
script loop provides this capability by enabling the user
to specify for partition 1 the name of the function, the
lower of the two numbers "nl" as partition 2 and the higher
number "n2" as partition 3.
< loop >
%zs,6,[2]/%zs,7,%su,[3],[2]//%zi,7/%lpl,[1]/
< lpl >
%lp2,[1],%zq,6//%zi,6/%zd,7,,,l%lpl,[1]///
< lp2 >
i
/%ps,-4, ,[2]/ %[1],[2]/
For example the user wishes to ascertain the "roman" number
equivalent of the decimal numbers from 105 to 116:
TT.-.
{} %loop,dtr,105,116/=
n
105
CV
u
106
CVI
u
107
CVII
u
108
CVIII
u
109
CIX
u
110
CX
n
111
CXI
u
112
CXI I
u
113
CXI II
o
114
CXIV
(j
115
cxv
0
116
CXVI
U
The expression named "hanoi" is a
classical example of recursive
capability; although the original is
said to be based on monks moving rings
between the three towers of Bhrama, the
to be better known for this puzzle.
The expression shown below was conceived by Dick Stone; it
solves the problem, with a minimum number of moves:
Often times it is desired to execute all II
procedure on each and every one of some 11 repeat 11
arbitrary number of "texts" in the IJ_[I
storage area; as an example a script
designed to provide a list of text names and the count of
characters in each text will be illustrated; the key to
this script was the use of "mt - multi part text"; it was
used to create the multi partition value "#2" seen in the
expression named "repeat".
< repeat >
%ii,[1],,,!%procl,[l]/%repeat[|2]///
< procl >
%os,
%ps,10, ,[l]/%ps,-5, ,%crd,[1]///
If, for instance, the only texts in the text area were
"repeat" and "procl", then the use of repeat with an "It -
list text function" would appear as follows:
TT.
{} %repeat%lt,(,)//=
{} repeat 26
{} procl 32
{}
The "skim" expression "skims off" the |1 Tl
first appearance of each different 11 skim 11
character of the string which is placed |J_[I
as an argument to the expression; the
result is returned as the value.
< skim >
%dt,,![l]//*rs,%i//%et,/
< i >
%ig,%crd,/,,!%k,&fc,////
< k >
% P t, ,[l]/%i,[l]/![l]/
A simple example of the use of "skim" follows;
TT'...
{} %skim,MISSISSIPPI/=MISP
U
ii-Tl
11 hanoi 11
name "hanoi" seems
Number 21
Dr. Dobb's Journal of Computer Calisthenics 8t Orthodontia, Box E, Menlo Park, CA 94025
Page 23
Increments in X and Y
In his book "Algorithms in SNOGOL4" Jim Gimpel, the author,
offers SKIM as an example of string manipulation; it is
interesting to note the typing effort required for the same
function in each language; it is assumed that a speed of
ten words per minute (or one character per second) is
reasonable for intellectual typing. At that rate the SAM76
script would take approximately 100 seconds, while the
SN0B0L4 example would require approximately 143 seconds to
typo up*
SAM 76 Language Functions 11
The SAM76 language functions described in the following
pages represent a first draft for test and evaluation
purposes, and include all of the functions available in a
processor for that language initially coded for the INTEL
8080 and Zilog Z-80 microprocessors.
In particular these functions properly represent the action
expected for processors which have the <ncra>
identification; see function [@n).
Ttie references listed below should be used to provide
information as to language syntax, method of use, and
applications:
1. "SAM76 - A language based on I I II
"Strachey's GPM and Me Ilroy's M6", II References II
by Claude A. R. Kagan, dated august |J_[I
1976, and available as report R
76-301 from the IEEE Computer Society, 5555 Naples Plaza,
Long Beach, CA, 90803.
2. "SAM76 Language Primer" to be published.
3. Notes on loading and using SAM76, from the Amateur
Computer Group of New Jersey.
The author would greatly appreciate feedback, particularly
if errors are found in this document, or if the definitions
do not seem to correspond to the action encountered in a
given processor.
xnl,ynl, ... xn,yn
con Condition
EQ Equal
GT Greater Than
LT Less Than
ZE Zero
GE Greater than or Equal
LE Less than or Equal
UC Upper Case
LC Lower Case
When a radix greater than 10 is used upper case alphabetic
symbols represent the ensuing integers starting with "A"
being equivalent to 10 in base 10, "B" to 11, and so on.
Lower case characters are used when the radix exceeds 36.
II--
I I Function Definitions
II _
238 - |@f,s0| wh@ are Functions
The value of this function is a list of built-in functions
available within the system. Each function mnemonic is
preceded by the string of characters symbolized by "sO". It
is advisable to use the "neutral" form of expression as
shown below:
&@@f, /={value will be list of functions)
Note use of two since that symbol is a warning
character it must be protected, and in the above example it
is . used as the single character protector to protect
itself.
239 - I@nI wh@ is processor ser. Number
The value returned through execution of this function is
the version number of the processor being used. This number
is tested by some of the functions - and may also be so
tested by the user - to ascertain c xnpatibility between
scripts and run time load modules that may be moved between
systems and users.
Ancelme Roichel
Box 257 - RR1
Pennington - N. J., 08534
Notation used in list of functions
# Preliminary definition - no ID number assigned
I function,argl,arg2,...,argn| Active form of execution
\function,argl,arg2,—,argn\ Neutral form of execution
@ "at" (wh@ means "what")
c2,cl, ..
,. ,c
Single characters
s2,sl, ..
.. ,s
Character strings
sO
Prefixing character string
t2,tl, ..
.. ,t
Names of Texts
f2,fl, ..
.. ,f
Names of Files
d2,dl, ..
.. ,d
Decimal Numbers
n2,nl, .,
.. ,n
Numbers in current radix
x2,xl, .
.. ,X
Binary numbers (octal/hex)
vz
Value if function fails
vt
Value if function True
vf
Value if function False
vO
Value if function zero
v+
Value if function positive
V-
Value if function negative
dev
Device
a2,al, .
.. ,a
Abbreviations
237 - |@t| wh@ is processor Title
The value of this function provides information as to the
authorship of the processor being used; a typical example
is:
&@@t/=<ncra> indicating that the authors are:
"Neil Colvin Claude Roichel Roger Amidon.
159 - Iab,sl,s2,vt,vfI Alphabetic Branch
This function compares the character strings denoted by
"si" and "s2" in terms of their "ASCII" binary value; if
the string "si" has a lesser value than the string "s2"
then the value of the expression is the string denoted by
"vt", else the value is the string denoted by "vf"; if the
value strings are expected to contain executable or
syntactically meaningful symbols they should be protected
within the expression.
128 - Iad,nl,n2,n3,...,n| Add
The value of this expression is the arithmetic sum of the
integer numbers denoted by "nl", "n2", ... "n". Each of the
arguments is examined from right to left until a symbol not
representing a valid number in the current number base is
encountered; non numeric symbols prefixing the arguments
are ignored with the exception of those in argument "nl"
which is carried into the value string of the expression.
Page 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
34
For example:
148 - |cld,t|
Characters Left of Divider
%ad,dog5,cat6/={dogll)
Negative numbers are indicated in the usual manner with a
sign which must immediately precede the string of
integers it applies to thus:
%ad,dog-5,cat6/={dogl)
Omitted arguments (such as adjacent commas) have the value
of the "null string" and a numeric value of zero (0) as
illustrated in the following example:
%ad,dog,/={dog0}
160 - Iai,s0,sl,s2,_,s| Alphabetic Insertion
Hie value of this function is a character string in which
the string denoted by "si" has been inserted ahead of the
first of the subsequent argument string which has a greater
alphabetic value; each of the strings which form the
arguments of the expression are returned with a copy of the
string symbolized by "sO" preceding it.
187 - |and,xl,x2| And the bits
The value of this function is the result of performing an
anding of the two binary numbers represented in the current
"X" base by "xl" and "x2".
161 - |as,s0,sl,s2,...,s| Alphabetic Sort
The value of this function is a character string in which
the sequence of the strings denoted by "si", "s2", ... "s"
is rearranged to be in proper alphabetic sequence; each of
these strings is preceded by the string denoted by "sO” in
the result:
%as,(,),horse,cat,dog/=(,dog,cat,horse}
Note the use of "(,)" for "sO"; this is typical of lists
that the user may wish to use in a variety of functions
which have arbitrary number of arguments.
220 - |bf,f,vz| Bring File
Execution of this function serves to bring from auxiliary
storage the file whose name is denoted by "f"; if this file
does not exist, then the value of the function becomes the
string symbolized by "vz".
113 - lca,s| Change Activator (current)
\ca,s\ Change Activator (initial)
The purpose of this function is to change the symbol which
terminates input from its current value to that denoted by
the first character of the string denoted by "s"; active
form is used to change the operational activating character
whereas the neutral form is used to change the initial
table.
195 - |cfc,dl,s| Change Fill Character schema
\cfc,dl,s\ Change Fill Char, (initial)
The purpose of this function is to enable the user to
specify the number of that character which is the first one
of the string denoted by "s" that will be automatically
output at the beginning of each "new line"; usually these
will be "nulls" but they may be any other character the
user wishes to use. Active form of the expression changes
the table in active use, while the neutral form changes the
initial table; see [cnb].
193 - lcin,tl,dl,...,t,d| Change Id Number
To be defined and coded.
Number 21
The value of this function is the (decimal base) number of
characters located between the beginning of the "text"
whose name is denoted by "t" and the current location of
the internal "text divider" of said text.
191 - |cll,d| Change Line Length (active)
\cll,d\ Change Line Length (initial)
The purpose of this function is to change the number of
characters that the processor will output before
automatically inserting a "new line" code; the desired
value is the decimal number denoted by "d" in the
expression; the active form changes the actively used
constant, while the neutral form changes the initial
condition table; see [cnb].
133 - |cnb,d| Change Number Base (active)
\cnb,d\ Change Number Base (initial)
The purpose of this function is to change the radix of the
processor's arithmetic functions; this is always expressed
as the decimal number symbolized by "d" in the expression;
see [qnb]; active form of the expression changes the value
of the radix used during the actual operations while the
neutral form changes the initial table. Note that the
neutral change can only be effective while the processor is
in unprotected memory, and will have no effect if the
processor is executed from read only or protected memory.
266 - |cpc,tl,dl,...,t,dI Change Protection Class
To be defined and coded.
147 - |crd,tl Characters Right of Divider
Hie value of this function is the (decimal base) number of
characters located between the beginning of the "text"
whose name is denoted by "t" and the current location of
the internal "text divider" of said text.
203 - |cro,sl| Change Rub Out char, schema
\cro,sl\ Change Rub Out (initial)
The purpose of this function is to permit the user to
specify as the first character of the string denoted by
"si" that symbol desired to serve the character delete
function; in addition the user may specify the next two
characters of that string to be output before and after,
respectively, the deleted string of characters. The active
form changes the user table, while the neutral form of this
function changes the initial table; see [cnb).
132- |ct,tl,t2,t3,...,t| Combine Texts (superseding)
\ct,tl,t2,t3,...,t\ Combine Texts (save current)
The purpose of this function is to create a text, whose
name is denoted by "tl” which will contain the
"concatenation" of the texts whose names are denoted by
"t2", "t3", ... "t".
The active form of the expression will also delete the
current text named "tl" if any; the neutral form of the
expression will not cause deletion of any pre-existing
texts.
250 - |cwc,sl| Change Warning Character
\cwc, ... \ Change Warn. Char, (initial)
The purpose of this function is to allow the user to select
other symbols for syntactic purposes than those initially
defined in the language; see [gwc]. The active form of this
function changes the current user tables while the neutral
form changes the initial table; see [cnb].
Page 25
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
35
261 - |cws,d|
\cws,x\
Define Text (superseding)
Define Text (save current)
Change work Space
This function allows a respecification of the upper limit
of space required for function execution and text storage;
the neutral form is used to allow a binary (hex, octal ...
) number denoted by "x" to be entered; the active form uses
the decimal nunber system instead; see [qws].
171 - |cx,sO,s| Character to "X"
This function returns as a value a sequence of binary
numbers, each preceded by the string denoted by "sO" which
result from converting the character string denoted by "s";
the conversion is in the current specification for the "X"
base; see [cxb, qxb, xc].
200 - |cxb,d| Change "X" Base (active)
\cxb,d\ Change "X" Base (initial)
Through use of this function, the user may change the
specification of the radix (or base) for those functions
which operate in the "X" base; "d" symbolizes the decimal
value of the desired new radix, and this should normally be
either "2" or "4" or "8" or "16"; active and neutral forms
operate with respect to the "X" base in the same manner as
described for the "cnb - change number base" function.
103 - Idt,t,s,dl,d2|
\dt,t,s,dl,d2\
This function is used to create a "text" whose name is
denoted by "t", containing the string of characters
symbolized by ”s"; arguments denoted by "dl”, "d2" are for
undefined purposes.
The active form of the expression serves also to erase the
text whose name is "t" if currently in the text area; the
neutral form will not cause any text deletion.
173 - |dx,d,x| Decimal to "X"
The value of this function is that number which results
from converting the decimal number denoted by "d" to its
equivalent in the current "X" base; the argument symbolized
by "x" is undefined; see [xd, cxb, qxb].
206 - |ea,tl,t2,_,t| Erase All excepting
This function is used to erase from the text area all
defined texts; excepted from this erasure are the texts
whose names are denoted by "tl", "t2", ... "t"; full
erasure is accomplished as shown below:
%ea/=
259 - |da,s0| Date
The value of this function is the current calendar date in
the sequence of "day, month, and year"; each of these
elements is preceded by the string of characters denoted by
"sO”.
The date may be either user entered (using the "sda"
function) or may be automatically generated by a system
clock or calendar; see [sda].
131 - |di,nl,n2,vz| Divide
The value of this function is the integer result of
dividing the number denoted by "nl", by the second number
denoted by "n2"; if the result of the division would be
indeterminate - "n2" = zero - then the value of the
expression is that string denoted by "vz".
Treatment of non numeric, signs, and null strings is
identical to that described in the "ad" function.
208 - |dq,s| Define Quote
The purpose of this function is to enable the user to
specify the character that is to be recognized by the scan
algorithm as an unconditional protecting character. To be
further defined.
- ldr,t,a,o,v| Define Relationship
To be defined and coded.
164 - |ds,d,s| Duplicate String
The value of this expression is a concatenation of that
number of copies of the string "s" which is denoted by the
decimal number "d".
This function may be quite properly used to "DO" something
a desired number of times as illustrated below:
%ds,5,!%dt,x,%ad,3,%x/////=
This example shows a most awkward way of creating a text
named "x" which contains the product of 5 and 3.
207 - |ed,t,dl,d2,vz| Extract "D" characters
The value of this function is a string of characters
extracted from the text whose name is denoted by "t"; the
first character returned is that which is found distant to
the right of the text divider by the number denoted by
"dl”, and the number of characters returned is denoted by
the number "d2".
If there are absolutely no such characters available then
the value of the expression is that string denoted by "vz"
which is always treated actively; this is regardless of
whether the original expression was used actively or
neutrally.
224 - |ef,fl,f2,...,f| Erase Files
This null valued function is used to erase from auxiliary
storage the files whose names are denoted by "fl", "f2",
... ”f".
151 - |ep,t,pl,p2,...,p| Erase Partitions
This function serves to delete from the text named "t" any
partitions that may be found in it to the right of the
internal text divider.
If arguments "pi", "p2", and so on are specified, then only
those partitions with values denoted by these arguments are
deleted.
- ler, ... I
To be defined and coded.
Express Relationship
104 - |et,tl,t2,...,t| Erase Text
\et,tl,t2,...,t\ Erase all occurences of Text
This function is used to erase from the text area texts
whose names are denoted by the arguments of the expression;
the active form of the expression erases only the latest
version of the named texts, should more than one version
exists in the text area.
Page 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
249 - |etb,s|
Fetch "D" Matches
Erase Trailing Blanks
This function, which Neil Colvin insisted be made
available, serves to delete from the character string
symbolized by ”s" all blanks which immediately precede the
occurence of "new line' 1 codes; particularly useful when
reading punched cards with many trailing blank columns.
112 - lex,f| Exit
This function is used to exit from the processor back to a
system monitor; if the expression contains any arguments,
such as "f” then a file is created in auxiliary storage
which contains all of the user work space including
variables, working area and text area.
This file is given the name denoted by "f", and may be
reloaded on any other system and the action interrupted by
the execution of this function is then resumed at the same
point.
Successful resumption of action is subject to compatibility
as determined by verification of the system authorship and
version number.
226 - |fb,f,vt,vf| File Branch
The value of this function is the string symbolized by "vt"
if the file whose name is denoted by "f" is to be found in
external storage; if not the value of this function is that
string symbolized by ”vf".
137 - lfc,t,vz| Fetch Character
The value of this function is the character to be found
immediately to the right of the internal text divider of
the text whose name is denoted by "t"; if such a character
exists then the text divider is advanced to point to the
next available character - or alternatively to the end of
the "text".
If no character is available then the value of the
expression is that string denoted by "vz" which is always
treated actively.
138 - |fdc,t,d,vz| Fetch "D" Characters
The value of this function is that decimal number of
characters denoted by "d" which is to be found to the right
or left of the internal divider of the text whose name is
denoted by "t"; a positive number specifies to the right,
and a negative number to the left; the text divider is then
relocated to point to the next character available if to
the right, or to the first character returned in the value
string if to the left.
Should there be absolutely no characters (not even one)
available for the value, then ”vz" represents the string
which will be returned as the value of the expression, and
this value is always treated actively.
139 - |fde,t,d,vz| Fetch "D" Elements
The value of this function is that string of characters to
the right or left of the text divider of the text whose
name is denoted by "t" which comprises the number of
elements specified by the decimal number "d"; an element is
that which is found between partitions.
The divider is then moved either to the right or left to
point either to the next character to be read (if to the
right) or that character which corresponds to the first
character of the value string (if to the left).
If absolutely no characters are returned, then the divider
is not moved and the value of the expression is that string
symbolized by "vz" which is always treated actively.
140 - |fdm,t,d,s,vz|
The value of this function is a character string taken to
the right of the text divider of the text whose name is
denoted by "t"; the contents of the text "t" is scanned
searching for occurences of the string denoted by "s"; when
that number of occurences equal to the number ”d" is found
then the divider is relocated to point to the next
immediately following character, and the value string is
that which lies between the old and the new divider
locations.
If the required number of matches is not found, then the
divider is not moved, and the value of the expression is
that string denoted by "vz", which is always treated
actively.
If the desired number is negative, then the action takes
place to the left of the divider instead of to the right.
141 - |fe,t,vz| Fetch Element
The value of this function is that string of characters
which is to be found immediately to the right of the
current location of the divider in the text named "t" up to
the next encountered partition - or end of text.
The text divider is moved to point to the immediately
available next character.
If absolutely no characters are to be found, then the value
is the string denoted by "vz", which is always treated
actively.
142 - |ff,t,d,vz| Fetch Field
The value of this expression is that string of characters
to be found to the right of the first occurence of a
partition of value symbolized by "d" until the next
partition is encountered, or to the end of the text named
"t"; the divider is then moved to point to the next
available character.
If absolutely no characters are returned, then the divider
is not moved, and the value of the expression is the string
symbolized by "vz" which is always treated actively.
143 - |fl,t,s,vz| Fetch Left match
The text named "t" is searched to the left of its internal
divider for a string identical to that denoted by "s"; if
such a string is found then the divider is moved to point
to the first character of that string and the value of the
expression is that group of characters to be found between
the new location of the divider and its old location.
If no such matching string is found, then the divider is
not moved, and the value of the expression is the string
"vz" which is always treated actively.
145 - |fp,t,xl,...,x| Fetch Partition
The value of this function is the next partition to be
found in the text whose name is denoted by "t"; the text
divider is moved to point to the next ensuing character.
144 - |fr,t,s,vz| Fetch Right match
The text named "t" is examined starting at the current
location of the text divider for a string identical to that
denoted by "s"; if such a string is found, then the divider
is moved to the next character which follows this string
(or the end of the text) and the value returned is that
string of characters which lies between the old and the new
locations of the text divider.
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 27
If no such match is found, then the value of the expression
is the string denoted by "vz", always treated actively, and
the divider is not moved.
106 - Ift,t,sl,s2,...,sI Fetch Text
Hie value of this function is the contents to be found in
the text named "t" to the right of its internal text
divider.
Any partitions found in that portion of the text are
replaced with the strings denoted "si", "s2", ... "s", in
such a manner that partitions with value "1" are replaced
by "si", value 2 with "s2" and so forth.
115 - IicI Input Character
Hie value of this function is one character the source of
which is the currently selected input device; this may be
absolutely any one single character in the system character
set.
116 - |id,d| Input "D" characters
Hie value of this function is a stream of characters from
the current selected input device; the action is terminated
when that number symbolized by "d" has been received; in
the case of certain sources, an End of File will also
terminate.
210 - |ftb,t,s,vz| Fetch To Break character
Hie value of this function is a string of characters taken
from the current location of the internal text divider of
the text whose name is denoted by "t" to the first ensuing
character in text "t" which is found in the string
symbolized by "s"; the text divider is moved to the first
character which follows that which terminated the scanning
action.
If no character is returned, then the divider is not moved
and the value of the expression is that string symbolized
by "vz" which is always treated actively.
211 - |fts,t,s,vz| Fetch To Span character
Hie value of this function is a string of characters taken
from the current location of the internal text divider of
the text whose name is denoted by "t" to the first ensuing
character in text "t" which is not found in the string
symbolized by "s"; the text divider is moved to point to
the first character which follows that which terminated the
scanning action.
If no character is returned, then the divider is not moved
and the value of the expression is that string symbolized
by "vz" which is always treated actively.
212 - |hc,s| How many Characters
Hie value of this function is the actual number of
characters comprising the string symbolized by "s".
150 - |hm,t,s| How many Matches
Hie value of this function is that number of occurences of
the string of characters symbolized by "s" in the text
whose name is denoted by "t".
149 - |hp,t,d| How many Partitions
The value of this function is the number of partitions to
be found to the right of the text divider in the text whose
name is "t"; if there is no explicit third argument, then
the value represents the total number of partitions; if
argument three is specified, then the value is that number
of partitions whose value is eoual to the number symbolized
by "d".
114 - |ht,t| Hide Text
\ht\ Hide all Texts
Hie purpose of this function is to put a screen or fence in
the text area such that only those texts created after that
whose name is denoted by "t" are available.
This fence is removed by execution of this function with no
arguments; if it is desired to conceal all of the text
area, the the neutral form is to be executed.
153 - |idt,d| Input "D" Texts
Hiis function serves to place into the text area "texts"
which are loaded from various types of auxiliary storage
media and created through use of the "output text"
functions.
136 - Iig,dl,d2,vt,vf| If Greater
Hiis expression compares in an arithmetic sense the two
strings denoted by "dl" and "d2"; if the value of "dl" is
greater than that of "d2", then the value of the expression
is that string symbolized by "vt", else the value is that
string symbolized by "vf".
135 - Iii,sl,s2,vt,vf| If Identical
Strings symbolized by "si", and "s2" are compared, if found
to be absolutely identical, then the value of the
expression is that string symbolized by "vt"; if not
identical the value is the string symbolized by "vf".
117 - Iim,sl,s2,...,s| Input to Match
Hie value of this expression is a stream of characters
coming from the currently selected input device;
termination of this stream occurs as soon as one of the
strings symbolized by "si", "s2", ... "s" has been
encountered; the value includes the string that caused
termination.
102 - |is,dev| Input String
Hie value of this function is a stream of characters coming
from the currently selected input device; termination
occurs as soon as the currently specified "activating
character" is encountered; this activating character does
not become part of the value string of the function.
152 - |it| Input Text
Hie purpose of this function is to place in the text area
one text loaded from some auxiliary storage media, which is
in the format generated through use of tne "output text”
functions.
213 - |iw,nl Input Wait
Hiis function sets up an internal timer which becomes
effective for the next ensuing input function, such as
"is", "ic", "idc", "im"; automatic termination of the input
process takes place at the end of the specified time
interval even though normal terminating conditions
specified for these functions may not have been met.
Hie duration of the time interval is specified by "n" which
is in seconds.
Page 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
38
- |lef,dev|
Load External Function
To be defined and coded.
If that last previously executed implied "fetch" was
active, then the value of this function is that string
symbolized by "vf".
216 - IIf,sO,dl.dl List Files
The value of this function is a list of the names of the
files in auxiliary storage; each file name is preceded by
the string symbolized by ”s0”.
Additional arguments are to be defined.
- Hr, ... | List Relationship
To be defined and coded.
188 - |not,x| Not (complement) the bits
The value of this function is the complement of the binary
number (in the current "X" base) symbolized by "x".
209 - |nu,sl,s2,...,sl Null
The purpose of this function is to cause execution of the
function whose name is denoted by "si", with appropriate
arguments n s2", ... "s"; that function is executed but any
resulting value string is suppressed.
105 - IIt,s0,dl,d2,...,d| List Texts
The value of this function is a list of the names of the
texts to be found in the text area; each name is preceded
by the string symbolized by "sO".
Arguments symbolized by "dl", "d2", ... have not been
defined.
110 - lmc,d| Multi-partition Character
The value of this function is the "multi-partition
character" whose value is denoted by the decimal number
"d".
146 - |md,t,d| Move Divider to pos. "d"
\md,t,d\ Move Divider "d" increments
This function is used to move the text divider in the text
whose name is denoted by "t". Active form serves to move
the divider the number of positions from the left end of
the text if "d" is positive, or from the right end if
negative; the neutral form is used to advance or retreat
the divider from its current location that number of
positions specified by the number "d".
It should be noted that these moves are positional and do
not distinguish any difference between partitions and
characters; this is the only function available to position
the text divider other than immediately preceding a
character.
109 - |mt,t,sl,s2,...,s| Multi-part Text all matches
\mt,t,sl,s2,...,s\ Multi-part Text next match
This function serves to replace in the text whose name is
denoted by "t" the strings symbolized by "si", "s2", "s"
with multi-partitions of values respectively "1", "2", ...;
the neutral form of this function only replaces the first
occurence of these strings found in the text.
130 - |mu,nl,n2,vz| Multiply
246 - loj,s,sl,d,s2l Output Justified lines
To be defined and coded.
248 - |op,s,sl,d,s2| Output Paddded lines
To be defined and coded.
186 - |or,xl,x2| Or the bits
The value of this function is the logical or of the two
binary number strings "xl" and "x2" expressed in the
current "X" base.
101 - |os,s| Output String
This function causes the selected output device to output
the string of characters symbolized by "s".
154 - |ot,tl,t2,...,tI Output Texts
This function outputs to the selected channel, the texts
whose names are denoted by "tl", "t2", _ "t", in a format
which preserves all of the internal conditions of the text;
this includes location of the internal text divider, and
text partitions if any.
108 - lpc,d| Partition Character
The value of this function is a "partition character" of
value symbolized by the decimal number "d".
174 - Ipl,sl,s2,...,s| Plot
This is a general purpose plotter or display control
function; details may vary in its use as a function of the
system in which it is used. Certain subfunctions as
described below have been standardized:
The value of this function is the arithmetic product of the
numbers symbolized by "nl", and "n2". The same rules as to
sign and non numeric matter apply for this function as they
do for the "ad" function.
Should there be an overflow condition arise as a result of
the execution of this function, then the value of the
expression is that string symbolized by "vz".
Ill - |ni,vt,vf| Neutral Implied
This function returns the string symbolized by "vt" if the
last previously executed implied "fetch text" was neutral.
Ipl,lf,s0l
I pi,as,port,time I
I pi,nm|
|pl,vm|
lpl,cal|
|pl,tek|
lpl,mq,x|
List of Plotter subfunctions
Assign output port and time delay
Output plotter control information
Return as value control information
Set up for "Calcomp" plotter
Set up for "Tektronix" display
Rotate to quadrant "x"
162 - Ips,d,sl,s2| Pad String
The value of this function is the string "s2" to which is
added either to its right or to its left enough
duplications of string "si" so that the total size of the
value string becomes equal to the number symbolized by "d";
positive values of "d" pad to its right, and negative
values to its left.
Number 21
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Page 29
39
107 - Ipt,t,sl,s2,...,sl Partition Text all matches
\pt,t,sl,s2,...,s\ Partition Text next match
The purpose of this function is to replace in the text
whose name is denoted by "t" the strings symbolized by
"si", "s2", ... "s” with partitions identified by numbers
which correspond to the position of the strings in the
expression; that is to say "si" is replaced by a partition
value "1", "s2" by partition value "2" &c.
In its active form, this function serves to replace all
occurences of the desired strings; in its neutral form only
the first occurence found is so replaced for each of the
specified strings.
Action takes place starting at the current location of the
internal text divider which is not moved by this function.
A particular example of interest might be:
&pt,animal,dog,dog,dog,dog/=
This example would in the text whose name was animal,
replace the first match with "dog" with partition value
"1", the second, "2", the third with ”3" and the fourth
with "4".
196 - Iqfc,s0| Query Fill Character schema
The value of this function is the current specification for
the optional fill character output immediately after each
"new line"; the parameters are each preceded by the string
symbolized by "sO"; see [cfc].
194 - Iqin,s0,tl,t2,...,t| Query Id Number
To be defined and coded.
197 - |qld,t| Query Left of Divider
The value of this function is the (decimal base) number of
positions - characters and partitions - located between the
beginning of the "text” whose name is denoted by "t" and
the current location of the internal "text divider" of said
text.
192 - Iqlll Query Line Length
The value of this function is the current specification for
the line length; this specification is changed through use
of the "ell" function.
134 - |qnb| Query Number Base
The value of this function is the current value of the
radix for arithmetic operations and functions.
198 - Iqrd.tl Query Right of Divider
The value of this function is the (decimal base) nun her of
positions - characters and partitions - located between the
beginning of the "text" whose name is denoted by "t" and
the current location of the internal "text divider" of said
text.
204 - lqro| Query Rub Out char, schema
The value of this function describes the current
specification for the use of the "rub out"; see [cro].
205 - Iqtal Ouery Text Area used
The value of this function is representative of the amount
of space consumed in the text area by user defined texts.
251 - Iqwc,a2,al,...,a| Query Warning Characters
The value of this function is a list of the currently
specified and functional warning characters of the
language.
262 - Iqwsl Query Work Space
\qws\
The value of this function is the upper limit of the user
work space; active form of this expression yields the value
as a decimal number; neutral form yields the value in the
current "X" base.
201 - Iqxbl Query "X" Base
The value of this function is the currently set radix for
the functions which operate in a "binary" or "X" base.
215 - Ira,d,sl,s2,s3,...,s| Return Argument
The value of this function is that string symbolized by one
of "si", "s2", "s3", ... "s" whose position corresponds to
the value of the decimal number symbolized by "d".
263 - |rcp,dl,d2,s| Return Character Picture
To be coded.
166 - |ri| Restart Initialized
Execution of this function causes immediate termination of
any unexecuted scripts, and causes return to the idling
condition, reinitializing all normally changed user
specifications.
202 - Iqofl Query Over Flow conditions
The value of this function are characters which may be used
to identify the cause of an interrupt or overflow
condition.
167 - |qp,t| Query Partition
The value of this function is the decimal identification of
the next partition to be found in the text whose name is
denoted by "t"; the text divider is not moved by this
function.
245 - Irj,s,sl,d,s2| Return Justified lines
To be defined and coded.
252 - |rn,n| Random Number
The value of this function is a number ranging between 0
and "n", randomly selected through a computational
algorithm; see [srn].
189 - |rot,d,x| Rotate the bits
267 - Igpc,s0,tl,t2,...,tl Query Protection Class
To be defined and coded.
me value of this function is that binary number which
results from a rotation of the binary number "x" expressed
ln current "X" base; the number of bits rotated is
specified by the decimal number "d"; the direction is
Page 30
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Number 21
40
Set Time
clockwise if the number is positive, and counterclockwise
if negative.
247 - |rp,s,sl,d,s2| Return Padded lines
To be defined and coded and coded.
165 - |rr,sl| Return to Restart
This function causes immediate cessation of execution of,
any unexecuted script, forces a return to the idling level
of the processor and then returns the value of the string
symbolized by "si"; if that string is an executable
expression, then said expression is executed.
163 - |rs,s| Reverse String
The value of this function is the string of characters
symbolized by "s” reversed, end for end.
228 - |saf,dev| Select All File function dev.
To be defined.
158 - |sari "Auto Return" on line feed
\sar\ no Auto Return on line feed
Execution of this function serves to enable (if active) or
disable (if neutral) the automatic generation of a
"carriager return" code when a "new line" code is output.
260 - Isda,da,mo,yrI Set Date
This function enables the user to set into the system the
current ( r any other) desired date.
258 - Isti,tl,t2,t3l
Through use of this function the correct current (or
incorrect if desired) time of day is established in the
system.
129 - Isu,nl,n2,...,n| Subtract
The value of this function is the result of subtracting the
number symbolized by "n2" from that symbolized by "nl"; all
rules indicated for sign and non numeric matter in the "ad”
function apply.
231 - Isw,sl,s2,s3,...,s| Switches
Special system dependent function for user definition.
232 - |sy,sl,s2,...,sl System functions
Special system dependent function for user definition.
127 - |tb,t,vt,vf| Text Branch
If the text whose name is denoted by "t" is to be found in
the text area, then the value of the function is that
string symbolized by "vt", else the value is string
symbolized by "vf".
257 - |ti,sl,s2| Time
The value of this function is the current time of day
derived from a system clock, in the format HH MM SS, where
HH represent Hours, MM represent Minutes and SS seconds;
these elements are separated in the value string by the
string symbolized by "si".
199 - |sem,dev| Set "Echoplex" Mode active
\sem,dev\ "Echoplex" Mode inactive
This function enables character echo from the system if
executed actively; if neutrally, then echo generation is
suppressed.
222 - |sf,f,tl,t2,...,tl Store File
This function is used to place into auxiliary storage under
the file name denoted "f", those texts whose names are
denoted by "tl", "t2", ... "t"; on completion of this
action, the named texts are erased from the text area.
If no texts are named, then the assumption is made that the
entire text area is to be placed into auxiliary storage.
157 - |sfd,fun,dev| Specify Function Device
To be defined and coded.
190 - |sh,d,x| Shift the bits
The value of this function is that binary number string
which results from a logical shift to the right or left of
the string whose binary value, expressed in the current "X"
base is symbolized by "x"; the number of shifts is
specified by the decimal number "d" and the direction by
its sign, positive to the right and negative to the left.
125 - |tm,d| Trace Mode activated
\tm\ Trace Mode deactivated
This function is used to enable step by step execution of
the scripts and functions of the language; once activated
each step is initiated by depression of the "new line" key
("line feed") or a specified number of steps may be
specified by the number symbolized by "d".
124 - Itmal
\tma\
Trace Mode All activated
Trace Mode All deactivated
Active execution enables full trace action; neutral
execution allows display only of expressions about to be
executed.
168 - |tr,t,s|
Trim
This function is used to replace multiple adjacent
occurences of the character symbolized by "s" with a single
such occurence in the text named "t".
218 - |uf,f,tl,t2,...,tl Update File
This function combines the action of "erase file" and
"store file" by first storing a file successfully before
erasing the old file version.
253 - |srn,n| Seed Random Number
Through use of this function the attomatic generation of
random numbers is initiated; the user seed number is
symbolized by "n" in the above expression.
169 - |ut,ccl User Trap active
\ut\ User Trap inactive
Activating of this trap through use of this function will
cause an automatic execution of a text (or function) whose
name is denoted by "cc"; this automatic execution takes
Number 21
Dr. Dobb's Journal of Computer Calisthenics 8t Orthodontia, Box E, Menlo Park, CA 94025
Page 31
41
place whenever the user attempts to make use of system
interrupt capabilities to escape out of executing "scripts"
when it is desired that such escape be inhibited.
118 - Ivt,tl,t2,...,tI View Texts
This function enables examination of defined texts,
indicating visually the location of internal text divider,
partitions and their values, as well as multipartitions.
181 - |wc,sl,s| Write Characters
Ibis plotter or display function generates a graphic
display from a font of vectors named "si"; the string
symbolized by "s" is the text string to be plotted or
displayed.
175 - lwi,xnl,ynl| Write Initialize
This null valued function serves to create a reference
value for the current position of the display pointer; the
"x" and "y" coordinates of this position are set equal to
the decimal integer strings found in the second and third
arguments respectively.
179 - |wl| Width Left
The value of this function is the incremental value of the
width of a character being plotted to the left of its
center of gravity.
178 - |wrl Width Right
The value of this function is the incremental value of the
width of a character being plotted to the right of its
center of gravity.
180 - |ws,xnl,ynl,_,xn,ynl Write Straight Lines
This function causes the generation of the appropriate
control information to cause the display of one or more
line segments starting at the current position of the
display pointer. Successive points are referenced by
consecutive incremental x and y argument pairs. The x and y
components are expressed as decimal integer strings. The
sign of the number indicates direction.
Non numeric matter preceding the "x" value causes certain
auxiliary functions to take place as follows:
U "pen up" or invisible vector
S Scale change for "x" and "y"
A Absolute position vector pair
I Incremental vector pair
0 Ouadrant rotation
0-3 clockwise, 4-7 counter clockwise
W Character width information
"x" left and "y" right of center
tr.-.-.—-----
{) %dt,rect,(,8,0,0,5,-8,0,0,-5)/=
{) %ws%rect//=
U
176 - |wx| Write "X" displacement
The value of this function is equal to the alqebraic
difference between the initial value "X" of the display
pointer position and the sum of any subsequent incremental
displacement values.
177 - |wy| Write "Y" displacement
The value of this function is equal to the algebraic
difference between the initial value "Y" of the display
pointer position and the sum of any subsequent incremental
displacement values.
An effective way to return the display pointer to its
original location is illustrated as follows:
TT..
{} %ws,U%wx/,%wy//
{)
Assuming it is desired to draw a rectangle,8 units wide,
and 5 units high:
170 - Ixc,xl,x2,...,x| "X" to Character
The value of this function is a string of characters whose
value is represented by the numbers in "X" base symbolized
by "xl", "x2", ... "x".
271 - |xcf,s,x| experimental Change Function
This function is used to assign a user defined machine
adress symbolized by the "X" base number "x" for the built
in function whose mnemonic is denoted by "s".
172 - |xd,x| "X" to Decimal
The value of this function is the decimal equivalent of the
number in the current value of the "X" base symbolized by
"x".
255 - Ixi,port I experimental Input
The value of this function is that number in the current
"X" base which results from an attempted input from the
port whose designation in the "X" base is symbolized by
"port".
123 - |xj,x| experimental Jump
Execution of this function cause a jump to the memory
location symbolized in the "X" base by "x"; a return from
programs encountered at that location will cause normal
reentry into the system scanner.
256 - |xo,x,port I experimental Output
Execution of this function enable output of the "X" base
value of "x" to the port whose "X" base id is symbolized by
"port".
270 - |xqf,s| experimental Query Function
The value of this function is the machine adress in "X"
base radix of the entry point for the function whose
mnemonic is denoted by the string "s".
119 - |xr,x| examine Register
The value of this function is the contents of the memory
location symbolized in the current "X" base by "x".
121 - |xrp,x| examine Register Pair
The value of this function is the combined contents of the
two memory locations, whose first location is symbolized in
the current "X" base by "x".
120 - |xw,xl,x2| experimental Write in reg.
Use of this function causes writing the value "xl" into the
memory location "x2"; both of these are in the current "X"
base.
Page 32 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
42
122 - |xwp,xl,x2|
experimental Write reg. Pair
Use of this function causes writing of the double word data
symbolized in the "X" base by "xl" in the memory location
whose first word is identified by "x2".
126 - lyt,t,s,vt,vfI Ys There
Ibis function searches the text whose name is denoted by
"t" for an exact match with the string symbolized by "s“;
if such a match is found, then the value of the expression
is that string symbolized by "vt”, else it is that string
symbolized by "vf".
182 - |zd,r,v-,vO,v+| "Z" reg. Decrement and branch
Execution of this function causes the contents of a special
register identified by "r" to be decreased by a count of
one.; if the resulting contents of that register are
greater than zero, then the expression value is that string
symbolized by "v+"; if egual to zero, then the value is
symbolized by "vO", and if less than zero the value becomes
the string symbolized by "v-".
183 - Izi,r,v-,v0,v+| "Z" reg. Increment and branch
The action of this function is identical to that described
for "zd", except that the designated register "r" is
increased by a count of one prior to testing.
184 - |zq,r| "Z" reg. Query
The value of this function is the current contents of the
special register designated by "r"; execution of this
function does not cause any change in said register.
185 - lzs,r,n| "Z" reg. Set
Ibis function is used to preset designated special register
"r" to the number symbolized by "n".
SAM 76 - Setting up the System
Tl
II
11
There are two versions available: II II
11 Availability 11
a. Z80 - little less than 8K
Uses RSTO thru RST6
b. 8080 - about 9 K
Does not use any RST locations
In addition the source code is available from a number of
ACNJ members if special adressing reauirements are
encountered or if it is desired to configurate a system
with fewer functions, or different use of the PST
locations.
Except as indicated above both versions are virtually
identical, and the information that follows applies to both
of these versions; in consequence user defined texts and
procedures may be successfully moved between systems using
either of these two versions.
Possible incompatibility may be ascertained through use of
the SAM76 function which reveals the version number thus:
tr.-.
(} %P@n/=21
{>
reveals the version number of the "romable object code".
a. Romable program loads at - 'h8000.
b. "Once Only" start at “h8000
initializes variables.
c. Restarts may be made at 8003 or 0.
2
Memory
utilization
d. System and user variables start at ~h400
e. Workspace is above ~h600.
I/O specifications, and user options: II II
11 System 11
a. APPLE/ZAPPLE I/O Conventions apply. 11 Differences 11
IJ_Li
b. Normally initialized to seek and take
available RAM.
c. Special use of control codes is as follows:
~C Return to Monitor
*X Cancel current material typed in
DEL Rubout (changeable by user)
~N Shift Out to alternate character set
“O Shift In back to regular character set.
The Line Feed key is viewed by SAM76 as being equivalent to
the "NULIN" code, as specified by ASCII; use of this key
serves to go to the beginning of the next line - combining
the functions of "Carriage Return and Line Feed". The
Carriage Return serves only to return to the beginning of
the same line; this permits underlining &c.
Modifying SAM76 tables and options:
There are two levels of modifications
which the user may apply in the process
of tailoring the SAM76 code to suit his
system and needs:
a. Permanent.
b. Local or temporary.
Ttie type of changes are identical but the location of the
table to be changed and the time at which the table is to
be changed are different.
Effectively there is a main table of variables and options
located in the "romable" or protected section of code;
after having executed a "GO" to “h8000 this table is copied
into the user work space starting at location "h40C.
After this initial entry at "h8000 entry should be made
only at "h8003 or at location 0 if the user wishes to
preserve any changes made in the duplicate table at ~h40C
either with monitor facilities or through the execution of
SAM76 functions which are available to establish a variety
of user options.
4
Fiddler's
Guide
Typical Permanent Changes:
Normally changes in the table at “h800C
should be limited to necessary
respecification of I/O adresses, and in
some special cases to the location of
the beginning and or end of the user work
5
Useful
Fiddles
space.
In addition the user may make permanent changes to such
parameters as the maximum length of line, and the
specification of the number of fill characters after each
"carriage return/line feed". (Note Line Feed is the proper
character used for this combined function).
Number 21
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Page 33
43
Table 1 lists the primary portion of the table at "h800C
with corresponding adresses of its duplicate at ”h40C.
Table 2 lists locations that may be of interest to the user
as candidates for permanent changes; since these locations
may all be changed within the framework of the SAM76
language, it is suggested that changes be made first in
that manner, and that the modified duplicate table at "h40C
be examined before making the desired changes in the
permanent table.
Caution should be exercised in changing 0P2 and TOPMAX so
that TOPMAX be greater than 0R2 by at least “h400 bytes.
I I
TABLE 2
(is continuation of TABLE 1)
TABLE 1
.SBTTL /Variables & once only code/
• PAGE
;[VAR1]
VAR1:
• BLKB
1
[80/4-0C]
JMP
BOOT:
. BLKW
1
[80/4-0D]
Monitor Exit
MSCI:
.BLKB
3
[80/4-10]
Console Input
MSRI:
.BLKB
3
[80/4-13]
Channel 2 Input
MSCO:
■ BLKB
3
[80/4-16]
Console Output
MSPO:
.BLKB
3
[80/4-19]
Channel 2 Output
MSLO:
.BLKB
3
[80/4—1C]
Channel 3 Output
MSCSTS:
• BLKB
3
[80/4—IF]
Console Status
MSCHK:
.BLKB
3
[80/4-22]
10 Check
MSSET:
.BLKB
3
[80/4-25]
IO Set
MSMCK:
• BLKB
3
[80/4-28]
Memory Check
$232:
• BLKB
3
[80/4-2B]
%sy,xl,x2,.../
$231:
• BLKB
3
[80/4-2E]
%sw,x0,.../
.
• BLKB
3
[80/4-31]
spare
OR2:
.BLKW
1
[80/4-33]
start active zone
TOPMAX:
.BLKW
1
[80/4-35]
text area limit
TOPLOC:
• BLKW
1
[80/4-37]
future3
SPARE4:
■ BLKW
1
[80/4-39]
future4
I
Notes with reference to Table 1:
a. The adresses indicated are those of the actual locations
which would be changed as required to suit individual
operating system requirements.
b. If it is desired to disable any of the monitor functions
which would be adressed via the vectors of Table 1, replace
the JMP with a RET - (for instance one might wish to
disable the automatic RAM grabber by putting a "RET" at
"h8027" - If this is done it becomes necessary to actually
stipulate the adress of the end of user workspace by
entering said adress at ~h8037).
c. $232, and $231 are locations of jump vectors for the
SAM76 functions "sy" and "sw" respectively. These are
intended for user applications; if not required it is wise
to change the adresses for these functions at “h802B and
*h802E respectively to the adress found at "h8031 - this
causes the message <nav-xxx> to be returned should these
two functions be tested.
d. Location labelled "TOPMAX" is usually shown as 00-00;
this in combination with the availability of the MEMCHECK
function of the ZAPPLE monitor triggers the automatic
determination of the upper limit of user work space. A non
zero value at that location takes precedence and serves to
restrict the user work space to that specified.
e. Location labelled "OP2" defines the beginning of the
user work space; this may be changed if the user wishes to
have clear space for his own purposes at it's normally
initialized value of 05FE.
TIR:
.BLKW
1
; 0
TO:
• BLKW
1
; TCO
TI:
• BLKW
1
; TCI
TT:
• BLKW
1
; TCT
TR:
■ BLKW
1
; TCR
TE:
.BLKW
1
; Till
RIX:
• BLKB
1
; N12
BIX:
.BLKB
1
; N10
MCH:
.BLKB
1
; "=" EQUAL
TCE:
• BLKW
1
; FNP1
CE:
.BLKW
1
; SCE
TO2:
• BLKW
1
; o
TC3:
• BLKW
1
; o
TCECT:
.BLKW
1
; 0
TCEAN:
■ BLKB
1
; 0
ROBOT:
.BLKB
1
; N177
RUBOl:
.BLKB
1
; N74
RUB02:
• BLKB
1
; N76
NULCH:
• BLKB
1;
null charact
NULCT:
.BLKB
1;
filler count
PLIN:
.BLKB
1;
line length
Notes regarding changes in Table 2:
a. PLIN contains the number of characters on a ling at
which SAM76 is required to automatically generate a
"NULINE" on the console device. This is usually initialized
in the permanent table at 72 decimal (“h48), and is changed
in the duplicate table by using the "ell - Change Line
Length" function thus:
TT.
(} %cll,64/=
U
would set line length at decimal 64; the permanent table
may be changed prior to being placed into protected memory
using the neutral form of this function.
b. NULCT, and NULCH locations are used to specify the
number and the type of "null" character the user wishes to
have automatically generated on the console device when a
"NULIN" is output to it. This is usually initialized at
zero count, and ASCII-0 for the character; to change this
requires the use of the "cfc - Change Fill Character"
function thus:
TT..
{} %cfc,*,4/=
U
puts 4 asterisks at beginning of each new line; the neutral
form of the function is used to change the permanent table.
c. ROBOT, RUBOl, and RUB02 are used to specify the
character to be used for character deletion purposes, and
the symbols that are desired to surround the string of
consecutively deleted characters; initially this is set to
be the ASCII - DEL code and the surrounding symbols are the
< and > brackets. Changing this makes use of the "cro -
Change Rub Out" function thus:
TT .
{} %cro,$AB/=
{}
Page 34
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Number 21
44
sets $ to be the deleting character and the deleted string
is bracketed by A and B; the neutral form of this function
may be used to change the permanent table.
d. MCH is the location of the character used to terminate
entry; this character is known as the "Activator".
Initially this is set to be the = sign, and is changed via
use of the "ca - Change Activator" function thus:
e. Three types of anomalies are flagged by output to the
console:
T Time out no tape or jammed tape
M Memory error
P Parity error in block
TT..
ft ica,Z/=
U
changes activator to be "Z"; use the neutral form to change
the permanent table.
e. RIX and BIX are the current specifications for the
arithmetic and logical or binary bases respectively. These
locations are initialized to provide base 10 for arithmetic
and base 16 or hex for logical functions. Within the
framework of SAM76 they are changed using the "cnb - Change
Number Base" and "cxb - Change X Base" functions; for
example:
f. For the afficionado format is described below:
16 Bytes “h80 or "o200
SOH "hi
DEL “hFF or “o377
1 byte Number of data bytes (0 means 256)
2 bytes Load adress (Low then High)
variable data bytes
2 bytes Check Sum
ii-ri
I I LOADIT - loader 11
TT..
{} %cnb,7/=
U
sets arithmetic base to be 7.
tr.—.
{} %cxb,8/=
{}
sets logical or binary base to octal.
The neutral form of these functions may be used to change
the permanent initialization table.
SAM76 - Loading the object code tape
The two versions are available in compressed binary form
for which a special loader is required; this loader is
usually to be found in normal hex loader format ahead of
the binary.
The normal procedure to load is as follows:
a. Load the hex formatted loader;
b. Ttie loader should be at “hlOOO to “h475; simply go to
“hlOOO if using APPLE/ZAPPLE monitors, otherwise change the
calls to F006 to reflect your own reader input routine
before running.
c. If using APPLE/ZAPPLE just do a G8000 to start SAM76,
otherwise make the appropriate changes as required with
reference to Table 1 first.
If you are using a machine with output lights at port FF,
then the progress of loading will be displayed. As each
block is successfully loaded a check sum will appear for a
few seconds then the adress of the new block being loaded
will be displayed. If the check sum remains, an error is
indicated and then it is necessary to stop the reader, back
up the tape to the beginning of the previous block, start
the reader and G400 again.
d. Test SAM76 by getting a list of available built in
functions by typing in the following:
&@@f, /=
-RADIX 8 ; added by editor
.TITLE /loadit/
.IOC 002000 ; “hl000
ZAPMON= 1
ZAPPLE= 170000 ; *hF000
SENSE= 377 ; “hFF
;Control Codes
OCDLE=
20
Data Link Escape
CCENQ=
5
Enquiry
CCEM=
31
End Message
CCSOH=
1
Start of Header
CCETB=
27
End of Tx Block
CCACK=
6
Acknowledge
CCNAK=
25
Neg. Acknowledge
CCSTX=
2
Start Text
•DEFINE SKIP2[R] =
(.BYTE
001I[[[R]&6]<31
GETLDR: CALL
GETBY
CPI
CCSOH
JZ
SOHFND
GETLDX: CPI
CCETB
JZ
RSEXIT
CPI
170
JNZ
GETLDR
CALL
GETAD
PCHL
;all done
SOHFND: CALL
GETBY
CPI
377
JNZ
GETLDX
LDR377: CALL
GETBY
MOV
C,A
MVI
E,0
MOV
D,E
CALL
GETAD
LOAD: CALL
GETBY
RCVOK: MOV
M,A
MOV
B,M
CMP
B
JNZ
MEMERP
I NX
H
DCR
C
JNZ
LOAD
Number 21
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Page 35
45
CALL
PARTST
JMP CETLDR
NIXNIX: MVI
C,"?"
SKIP2
D
MEMERR: MVI
C,"M"
SKIP2
D
PARERR: MVI
C,"P"
SKIP2
D
TIMERR: MVI
C,"T"
EREXIT: CALL
CO
RSEXIT: JMP
RESTART
GETAD: CALL
GETBY
MOV
L,A
CALL
GETBY
MOV
CMA
H,A
OUT
RET
SENSE
GETBY: CALL
RI
JC
TIMERR
PUSH
PSW
ADD
E
MOV
E,A
JNC
GETBYR
INR
D
GETBYR: POP
RET
PSW
PARTST; POSH
D
CALL
GETAD
POP
D
MOV
A,H
CMP
RNZ
D
MOV
A,L
CMP
RET
'E
•END ;Pseudo op added by editor
Quick Reference Information for the [j
SAM 76 Language_ jj
II I I An attempt was made, in the selection of
I| Mnemonics I I the mnemonics of the resident functions,
|J_[| to be consistent in the use and meaning
of words or terms represented by the
function names; generally, whenever reasonable, letters
used in the function names may be expanded as follows:
letter
position 1
positions
2 and/or 3
a
alphabetic
all
activator
b
bring
branch
base
c
change
character
c3
d
define
decimal
divider
e
erase
element
e3
f
fetch
file
field, function
g
gi
greater
g3
h
how many
h2
h3
i
input, if
identical
initialize
j
jl
jump
j3
k
kl
k2
k3
1
list
left
length
m
ml
match
mode
n
neutral
number
n3
0
output
o2
o3
P
partition
P2
P3
q
query
g2
q3
r
return
right
register
s
set, select
string
space
t
trace
text
t3
u
update, user
u2
u3
V
view
v2
v3
w
write
warning
work
X
experimental
"X" number
base x3
y
yi
y2
y3
z
Zpecial
z2
z3
In the above table only the more frequently or major terms
are indicated; positions marked with a letter number pair
are for possible reference.
It should be noted that the meaning of the words used in
the above table are consistent; that is to say that the
same connotation may be applied - for instance "text"
always means; "a named string of symbols to be found in the
text area".
11 Quick reference
1 1
resident function list 11
II
238 - I@f,sO1
wh@ are Functions
239 - l@n|
wh@ is processor ser. Number
237 - |@t|
wh@ is processor Title
159 - Iab,sl,s2,vt,vf1
Alphabetic Branch
128 - Iad,nl,n2,n3,...,n|
Add
160 - Iai,s0,sl,s2,...,s|
Alphabetic Insertion
187 - |and,xl,x2|
And the bits
161 - Ias,s0,sl,s2,...,s|
Alphabetic Sort
220 - |bf,f,vz|
Bring File
113 - |ca,s|
Change Activator (current)
\ca,s\
Change Activator (initial)
195 - |cfc,dl,sl
Change Fill Character schema
\cfc,dl,s\
Change Fill Char, (initial)
193 - lcin,tl,dl,...,t,d|
Change Id Number
148 - |cld,tl
Characters Left of Divider
191 - |ell,d|
Change Line Length (active)
\cll,d\
Change Line Length (initial)
133 - |cnb,d|
Change Number Base (active)
\cnb,d\
Change Number Base (initial)
Page 36 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
46
266 - lcpc,tl,dl,...,t,d|
Change Protection Class
147 - |crd,tI
Characters Right of Divider
203 - |cro,sll
Change Rub Out char, schema
\cro,sl\
Change Rub Out (initial)
132 - Ict,tl,t2,t3,...,t|
Combine Texts (superseding)
\ct,tl,t2,t3,...,t\
Combine Texts (save current)
250 - lcwc,sl|
Change Warning Character
\cwc, ... \
Change Warn. Char, (initial)
261 - |cws,d|
Change Work Space
\cws,x\
171 - |cx,sO,s|
Character to "X"
200 - |cxb,d|
Change "X" Base (active)
\cxb,d\
Change "X" Base (initial)
259 - Ida,s0|
Date
131 - |di ( nl,n2,vz|
Divide
208 - ldq,sl
Define Quote
- |dr,t,a,o,vl
Define Relationship
164 - |ds,d,s|
Duplicate String
103 - |dt,t,s,dl,d2|
Define Text (superseding)
\dt,t,s,dl,d2\
Define Text (save current)
173 - |dx,d,x|
Decimal to "X"
206 - Iea,tl,t2,...,tl
Erase fill excepting
207 - |ed,t,dl,d2,vz|
Extract "D" characters
224 - |ef,fl,f2,...,f1
Erase Files
151 - |ep,t,pl,p2,...,p|
Erase Partitions
- ler, ... I
Express Relationship
104 - Iet,tl,t2,...,t|
Erase Text
\et,tl,t2.t\
Erase all occurences of Text
249 - letb.sl
Erase Trailing Blanks
112 - |ex,f|
Exit
226 - |fb,f,vt,vfl
File Branch
137 - |fc,t,vz|
Fetch Character
138 - |fdc,t,d,vz|
Fetch "D" Characters
139 - |fde,t,d,vz|
Fetch "D" Elements
140 - |fdm,t,d,s,vz|
Fetch "D" Matches
141 - |fe,t,vz|
Fetch Element
142 - jff,t,d,vz|
Fetch Field
143 - |fl,t,s,vz|
Fetch Left match
145 - |fp,t,xl,...,x|
Fetch Partition
144 - |fr,t,s,vz|
Fetch Right match
106 - |ft,t,sl,s2,...,s|
Fetch Text
210 - |ftb,t,s,vzl
Fetch To Break character
211 - |fts,t,s,vz|
Fetch To Span character
212 - |hc,s|
How many Characters
150 - |hm,t,s|
How many Matches
149 - |hp,t,d|
How many Partitions
114 - |ht,t|
Hide Text
\ht\
Hide all Texts
115 - licl
Input Character
116 - lid.dl
Input "D" characters
153 - lidt.dl
Input "D” Texts
136 - 1 ig,dl,d2,vt,vfI
If Greater
135 - 1ii,sl,s2,vt,vfI
If Identical
117 - Iim,sl,s2,...,s|
Input to Match
102 - I is,dev I
Input String
152 - |itl
Input Text
213 - |iw,n|
Input Wait
- lief,devI
Load External Function
216 - |If,s0,dl.d|
List Files
- Ur, ... I
List Relationship
105 - |lt,s0,dl,d2,...,d|
List Texts
110 - jmc,d|
Multi-partition Character
146 - |md,t,d|
Move Divider to pos. "d"
\md,t,d\
Move Divider "d" increments
109 - |mt,t,sl,s2,...,s|
Multi-part Text all matches
\mt,t,sl,s2,...,s\
Multi-part Text next match
130 - |mu,nl,n2,vz|
Multiply
111 - |ni,vt,vf|
Neutral Implied
188 - |not,xl
Not (complement) the bits
209 - |nu,sl,s2,...,s|
Null
246 - |oj,s,sl,d,s2|
Output Justified lines
248 - |op,s,sl,d,s2|
Output Paddded lines
186 - |or,xl,x2|
Or the bits
101 - |os,s|
Output String
154 - |ot,tl,t2,—,t|
Output Texts
108 - lpc,d|
Partition Character
174 - Ipl,sl,s2,...,s|
Plot
162 - |ps,d,sl,s2|
Pad String
107 - Ipt,t,sl,s2,...,sl
Partition Text all matches
\pt,t,sl,s2,...,s\
Partition Text next match
196 - Iqfc.sOI
Query Fill Character schema
194 - Iain,s0,tl,t2,...,tl
Query Id Number
197 - Iqld.tl
Query Left of Divider
192 - Iqlll
Query Line Length
134 - jqnb|
Query Number Base
202 - laofl
Query Over Flow conditions
167 - |ap,t1
Query Partition
267 - Iapc,s0,tl,t2,...,t|
Query Protection Class
198 - |qrd,t|
Query Right of Divider
204 - Igroj
Query Rub Out char, schema
205 - Iqtal
Query Text Area used
251 - |qwc,a2,al,...,al
Query Warning Characters
262 - Iqwsl
Query Work Space
\aws\
201 - Iqxbl
Ouery "X" Base
215- Ira,d,sl,s2,s3,...,s|
Return Argument
263 - Ircp,dl,d2,s|
Return Character Picture
166 - | r i |
Restart Initialized
245 - |rj,s,sl,d,s2|
Return Justified lines
252 - |rn,n|
Random Number
189 - |rot,d,x|
Rotate the bits
247 - Irp,s,sl,d,s2|
Return Padded lines
165 - |rr,sl|
Return to Restart
163 - |rs,s|
Reverse String
228 - |saf,dev|
Select All File function dev.
158 - Isarl
"Auto Return" on line feed
\sar\
no Auto Return on line feed
260 - lsda,da,mo,yrl
Set Date
199 - |sem,dev|
Set "Echoplex" Mode active
\sem,dev\
"Echoplex" Mode inactive
222 - Isf,f,tl,t2,...,tl
Store File
157 - |sfd,fun,devl
Specify Function Device
190 - |sh,d,x|
Shift the bits
253 - |srn,n|
Seed Random Number
258 - |sti,tl,t2,t3|
Set Time
129 - |su,nl,n2,...,n|
Subtract
231 - Isw,sl,s2,s3,...,s|
Switches
232 - |sy,sl,s2,...,s|
System functions
127 - |tb,t,vt,vf|
Text Branch
257 - |ti,sl,s2l
Time
125 - Itm.dl
Trace Mode activated
\tm\
Trace Mode deactivated
124 - Itmal
Trace Mode All activated
\tma\
Trace Mode All deactivated
168 - |tr,t,s|
Trim
218 - |uf,f,tl,t2,...,tl
Update File
169 - |ut,cc|
User Trap active
\ut\
User Trap inactive
118 - Ivt,tl,t2,...,tl
View Texts
181 - |wc,sl,s|
Write Characters
175 - |wi,xnl,ynl|
Write Initialize
179 - |wl|
Width Left
178 - Iwr|
Width Right
180 - |ws,xnl,ynl,...,xn,yn|
Write Straight Lines
176 - |wx|
Write "X" displacement
177 - |wy|
write "Y" displacement
170 - 1xc,xl,x2,...,x|
"X" to Character
271 - |xcf,s,x|
experimental Change Function
172 - |xd,x|
"X" to Decimal
255 - 1xi,port I
experimental Input
123 - 1xj,xI
experimental Jump
256 - |xo,x,port|
experimental Output
270 - |xqf,s|
experimental Query Function
119 - |xr,x|
examine Register
121 - |xrp,x|
examine Register Pair
120 - |xw,xl,x2|
experimental Write in reg.
122 - |xwp,xl,x2|
experimental write reg. Pair
126 - |yt,t,s,vt,vf|
Ys There
182 - |zd,r,v-,v0,v+|
"Z" reg. Decrement and branch
183 - |zi,r,v-,v0,v+|
"Z" reg. Increment and branch
184 - lzq,r|
"Z" reg. Query
185 - |zs,r,n|
"Z" reg. Set
Editorial Note: Object tapes for the 8080 and Z-80 versions of
SAM 76 are available from Computer Mart of New Jersey,
501 Rt. 27, Iselin, NJ 08830. Telephone: (201) 283-0600.
Tentative price will be $6.00. Computer Mart of New Jersey
will also be publishing a book containing all available docu¬
mentation on SAM 76. Available in early Spring, it will sell
for $9.95. -TRW
Number 21 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 37
47
An 8080 Disassembler and
Support Software for SOL
by Don Van Dyke
1125 Lakehurst Rd.
Livermore, CA 94550
This is a guide for the use of the following disassembler.
This disassembler performs most of the work of creating a file,
but may require human help in the case of lookup tables.
Requirements
1. 4k of ram in the area from D000 to E000 (hex in the same
area of ALS8 requires its scratchpad.
2. ALS8 assembler with TXT-2 addition. The user must there¬
fore also have a VDM-1 or SOL video display.
3. Enough ram to contain the disassembler, (2k) the created
file, the object code and the ALS8 assembler, though oper¬
ation of this program does not require that ALS8 be in
memory at the same time if the return point is modified.
4. SOLOS or CUTER. This program calls the standard input
routine and inputs from the current pseudo port.
Instructions
1. Load the object code to be disassembled into the portion of
memory where it normally resides.
2. Choose the correct version of the disassembler. Pick one
that is located out of the way of the object code, and leave
enough room for the ALS8 file. Remember that lk of
object will usually create about Ilk of source. Load the
program into memory.
3. Execute the program at the proper location, depending on
the version selected from the tape. Instructions will be dis¬
played on the screen.
4. After a few seconds the disassembly will be completed, at
which time it will jump to E060 (the standard ALS8 return
point), and will display the message “READY”.
5. Create a new file with the command:
FILE /name/ location
and perform an FCHK on it. You should then be able to
list, edit, or assemble the file at any location by using the
proper ALS8 commands.
Helpful Hints
1. In some cases, it may be necessary for the user to decide
where data tables are located in the object program. Meth¬
ods for determining where these tables are located are
provided in the program:
a. The ASCII equivalent for each operation is provided in
the comment field, if it is a letter, number, or punctua¬
tion symbol. This provides easy location of key words
in tables, and the user should exercise caution when
changing these areas.
b. Whenever the file contains a line such as:
0025 LC03BH DB OCBH
this means the op found at that location contained an
unused 8080 instruction, and is therefore part of a table
of some kind.
2. If the file contains any undefined symbol errors during
assembly, this means a label is required in a table, where a
two or three byte operation overlapped the op where the
label was to be placed. This situation must be resolved by
the user by the following method:
a. Assemble the file, noting any undefined labels and write
the labels down on paper.
b. Use the TXT-2 video editor to add an ‘EQU’ pseudo
statement immediately preceding the statement that
required the label. An example is shown below.
Suppose the disassembler creates a file as follows:
0001 L0104FH
LXI
H, L029FH
0002
MOV
A, M
0003
INX
H
- (etc.)
0455
LXI
B, 04567H
.... (etc.)
Then during assembly, this is generated:
017F21 00 00 U 0455 L0104FH LXI H, L029FH
(the ‘U’ denotes and undefined symbol)
Where L029FH should be on the SECOND BYTE of the
statement:
0455 LXI B, 04567H
The user should add the following line to the file:
»> 0000 L029FH EQU $ + 1 «<
0455 LXI B, 04567H
Note that this will assemble into the same thing, but will
allow the use of the label.
3. Notice that the line numbers generated are all 0000. This is
not a problem since the RNUM function may be used to
renumber the lines. Be sure to do this before using the line
editor, but it is not required for the video editor.
4. To insure compatability with assemblers, this program
generates a ‘6’, instead of SP, PSW, or M. Also, three byte
instructions contain the address in normal order, rather
than the reverse INTOL standard.
5. Since PCHL instructions can be hazardous in the case of
modifying H&L, this program generates a warning when it
encounters a PCHL op. The following message will appear in
the comment field:
******* <<<; WA rn IN G »>*♦*****
Support Software
This is a guide for the use of the support software for the
accompanying disassembler.
Requirements
1. ALS8 assembler with TXT-2 addition. The user must
therefore also have a VDM-1 or SOL video display.
Page 38
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Number 21
2. 12k of ram from D000 to FFFF (hex) (the standard ALS8
configuration).
3. SOLOS or CUTER. This program calls the standard input
routine and inputs from the current pseudo port.
Debug
1. This program uses the current file pointers from ALS8
and will help to restore crashed files. Although it cannot
work miracles, in most instances it will restore the file
to a point where the video editor can finish the job if
necessary.
2. It is recommended that DEBUG be loaded into memory
and be made an ALS8 custom command - i.e.:
CUSTE / DBUG /CBOO then when the file needs to be
fixed, make it the current file using: FILE /name/ <cr>.
Then type ‘DBUG’. After a few moments, ALS8 should
respond with an FCHK and a ‘READY’.
Adump
1. This program works in conjunction with SOLOS or CUTER
and will display the contents of memory in its ASCII
equivalent.
2. To use the program, load it into memory from the tape,
then make it a custom command by typing:
>CUST AD CBOO
The program will now operate like a standard dump by
typing this command:
>AD (beginning address) (end address)
Note that only characters inside the range from 10 to 7E
(hex) will appear on the screen, and anything outside that
range shows up as a
Exam
1. This program allows the user to examine the contents of
memory, and is very useful in locating tables and text in
memory when used in conjunction with ADUMP.
2. To use this program, load it into memory and execute it at
the beginning. What you will see is the first lk of memory.
To advance to the next lk segment, press the up arrow
(or ctrl-W), to back up to the previous lk segment, press
the down arrow (or ctrl-Z). To advance 8k at once, press
tab (or Ctrl-I). To exit to SOLOS or CUTER, press escape.
ALS8, TXT-2, VDM-1, CUTS, SOL, SOLOS and CUTER are
copyright by Processor Technology Corporation.
"O a in in in o o w in o if) 10 o©inin©ooinio© in in . © © in o
auooo o o o o © © © ©o © o© © ©o c© © o |© © © o
ii.o<r<rn uj o) <r o <i « n <t ilun « thoaotc <tu n <i . m m m
u.onnio ituco^trnisrt m o a a m m o* o m r i in m m n mm |rs rv m co
t-. rj ^ n u. m m a -- th <r a <x > cs r< m u lu <t a m < ck ci a uj n 'Oa •> c-j m in m <£ a <i m ml a n m a a a a ri m a r i O' a rv rv rv rv is
m n n ri ck a a u o h n u n c o w u u h n o n u l u n u n o ri u a u m uj m m rr cj ^ ci c-i rj u h h w n u o u u o © o o t
ooooooooooooooooooon'Oi>'UiiOMTN<tQOi , i'(iMiiaiuau.f'in'0!Miijora)N«Hiijrt<r<r<r?tfoi)'4-ij|ii.i'in^ii)'CN«itiuaortNnM'OMii)'«
o o o o o o © o o o © o o o o o o o © © © o o o ^ ^ ^ ^ c-i c-i n ri c-i ri n ri ci m m m m m m >r *t si - ) tiT li - ) m n n u " iit li - ) l"! u") >o c >o >c >c -c >c -o -o -c rv rs ps iv rs ?s n rs
0000 ©© 0000000 © 00000 © 000000 © 0 © 0000 ©© 000 © 0 © 0 © 00 ©© 00 ©© 00©©©0000 0 0 000 ©© 000 © 00000000 © 0©00
©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©ooooooo©©©©©©©©©©©©©©©©©©©©©©©©© 1 ©©©©©©©©©©©©©©©©©©©©©
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 39
49
ut
wCi
<r
<r <r -
* t- c
*x
u. a i
in <r
UJ
_i in
a, X
r u
m 2
in 3
<r 2
u u o
c c o
3 _l _l _l
: c z in in
: JOOQ
£ 2EU
cuujrori
2 u I 2 .
J <X t- <C u. 2 X £ L
<1 12 3 UJ ~ h- UJ
ct: o in
3 3 (- O ~ ►— UJ
C 2 in _l 13 u
in O U Cl
UJ -J 0 3
_i m 2 _j 2
- fc LL O
. <r o _j 3 co th
3 Cl U 3 C
3 2 M 2 3 1
2 IJ 3 CC 2 l
-J_]-J_J_IX_l_i UJHXHU. J3<r i<lH L-( LH l-H
IX3XI3 2<r^i2I3232T3i-2i=iCLNLLMu.NCLNCLN
Jtn_injXJUT!-2HE-!j£0T)JU£C(J£CUfl'U£CUfll
■ ***** i
o —
rx 'v
CM
rx
rn
rx
•o md o- o -• n « <r p < md &• c h n n ? n ; -o n
rsrvrv'^cccooococDCOooDoocoo-CN^n-Ch omO* o-
o c o c
oooooooooo
ccooocooooocc
cocso-*r4'r«rijT'OrscoO'C*^rjfn«?ii-5'C'vcoc>-o — C4fn«riiT'Crso3CKO-*rjm^-i,T'Orvooi>*o^cim«rm'Orvooi>o^rgM<-
o-occocccocoo — -'- 1 '— •—. h « n n n r< n n n r-j ri fi w n n n w m m n to to v ^ <r «r <r v c t <r ’nn in in in n
^ h n f; r; rj cm cm cm ri cm cm c. cm c« cm r; -< cm r. m cm cj cm cj (\ a c; ci cm r-j *. cm n cm ci cm cm cm cm m cm cm cm cm cm cm cm cm cm cm cm cm cm
ooocooooooooooccccoococoooooooccoocooocoooooooocoocoooooo
UJ -- UI fx CM UC’UJmUJ'CO* •0 0'
CM O Cl U U CJ U CM U r. o cm IJ CM
<ruj<i'0uj<EUj<iuj*3:Lj<ruj«ic
Uli.UlHLUa.UL.UL
CM If) fx C(JUJ-Mf*3'03i£
O O O O O O -H •
*n <x|ci n n <t ci n k, c n n ci <i «
-h'O O -H C — O CM CM CM CJ CM U
ufl<ICU<II>
N a U C N 4 u
ooooc ocooo
ON’TOO
m «r m *r <r
'OliKIflN-
m >c rs «t o
o o
o o o
o c
«T O
ULUHU — -HU -H->'0-H0-H0 — 0 CM rM CM CJ CM U NaUuNSU CM CM CM CM Cl UJ CJ U U Q Cl M Cl M U CM NO U H
u c cm mj o- cx <i cc ui iij uj ui Lj ulc -h r< m«r m •c'xciiiuu ciin in in in *crNC*cjQuujujujLJUj w ■— Mrrx<rciLj»-MMrfxc3uo cm in oc^uu
-* cm cm cm cm cm cm cm cm Cm cj cm cm cm CM.m momm .'■:mfnnm'nfo«r'<r*rHr«rc-*r«r'rT«T'<rHr<r«r«T*T<ri,TLTiiTL‘!u~i")'<5'C'0'0'C'orvfN.rvrvrsrsrv
ooooooeooocooooooooooooooo'o oooocoocoooooocooocoococoooooooooooooooococoooco
’H —H CM
<rcj<rcM<r*«ii=i<rcj<:*on'<im<rujCMm<rujcoujauicouooujcD
CM CJ CJ Cl CM UJ CJ U U Q CJ n n M U Cl Ml U rt u. U II U 1 l U It u u. u
■cuiHTNcou.o cm b) m > u u. o cm win'COO'Oiuui
i.i i^ .n i-. rv tv tv fvfvfvCDCcjDcaoOCDfflCDCOQO
ooooooooooo
Cl 2
2 UJ
O CC
U uC
12 3
in >
CC <E
<r in
X Wi
u u
O Cm
iXi O
2 2 3
O >-
•-mu
- cc 3
J U 3
3 in c
U 2 H LO »■
UI UJ h- UJ 3
12 CC in >- 2
2 I X
► c <r
« M O
X _| 3 •- 3 •- »-« H|-
2<IuUJQ3iU3LJ
•-ucccxmoccincc
x o 2 in
• * M J U
: x <r o a. >-
->X3»-*N‘-
> 2 3 U 2 UJ
>2UTCC
in u
) UJ MX
: >- cc
> o i cn i o '
• U2 Q LL i2
: O •- O >- fx <X 3
CC Ml
3 -
: u 2 :
C u. 3 )
J 2 O 3
) “) 2 *■
2 0 XU
in uj
> J-
<1 2
‘XXC
3 Ui UJ 3
2 2 2 <X
3 0>-23X2mT
lh O
U MX
3 in
o cn
CC UJ
2
in
Cl CD
2 in
3 _!
in in
in uj
< r cc
M UI 3
i 2 2
- O •— Cl Ui ll
i _! 222 X X IXXX 3 fi
> 2 •- 3 0 c c m cm a ci a i ro i x z x z :
■ o l z a o c at-ahu.ZLZ'jHrjH.
iaoLcauSoaoaoHONriucMLr
a x x
: 2 u o
M "H 3 U
) u c c
H JH JIJ J <
XXXXUIMTNUC
jkjjxjuti.
<x * * * a c
unsjrscoo'O-* cm mMTui^rv
to O IS CO CO O- CJ> O' »■ CK tMJ- >
ooooooooooooo
ooooooooooooo
* * * * 2
2*»****u
ooooooooooooo
- CM N <f n M3
o o o o o o
O' o
-H CM
o o
oooooooooiooooooocoooooooooooooooooooocooooocooooo
a u. c a u
nSOS>USjUiCD'Oi>
n cj co cj r — • — -
co CJ u. o -
rv tv ix m
o o o o
o o o o
3 3 0 3 3
o o o o o
ocooo
a- <i <i i <1 a u.
3 3 3 3 3 3 3
c o o o o o o
o o o c o o o
n iv x x r. 0 u l -m rj ^ m> c m ui it h n ri n ri ri M 1 n <0 ms > u u u u u u u u L ri t* x 0- u k n ii) co a w o f i \ c u l. -i •? mi &• a . : d
i^irt«iiii?!^i^SJSJ <:<I,I<I *' SfifiiIlSi ®l JS * i '' IiIi ** ilii:il5ifiiSiS * u uuuuuaaaaDaLLLLiJLLLUULLuo
ooooooooovjtoooooov^ooooooooooooloooooooooooooooocoooooooooooooooooooooo-*
^mxoOvmOO^OCOOOOOOCOOOOOOOOO. oooooooooooooooooooooooooooocooooooooooo
ooooooooooocoo
Page 40
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
50
I
£ 03 L- 3
5 z a e cr
t it cj *- c cj
cn z x o c ujc _i o
UIGSOIiC _J If! y_I GuJl
2 C Q • U O it 2 * V li. 03 ac U. ®
i ifl rj j « o *r uj cct-oN'ixa^
JO t-i _i i- O UJO
- _l UJt-Ul_ifVil_iI
- u. uiixouz ► >- x co
•ONcxiiar ct-GM
H- O 03 CJ i X
*-* _/ 1-* O UJi O
ut-»-c3_j<rx i _ix
03 03 3 Ld Z * >- X O
Cuiiii:r<n-on
r -i q t a co-5 O'O lu ox o
«r z cm <r z n «r z ct • t-^u. _j z — _i
X - 2 X - it X — lit £t - Z) - >- Z -< 3 Z
0_JXi<r^_liXi<Xr-J_JiZi<XMuJCCiCLCt- X _i X CC
(3 Ci _J
■4fsiXx*-4«X<E— _;<i<x
. z . i5-czc^a
_i Ou
22QzoiirNizozl2-iG^czc^azc3<iChruiGhazc-rjiG^a2««««Hiu
■5wj«j:wUTjii:«u~x!,*i:u3J<icu3_!<rcccciruo3"iXir!£03j«ju)")xu5r(flj<icc£i:ij'uonx
LLX_i*-<<r«rM 1 i:ci:ii:_i < iu.x_jt-icl<i*-»Ci:Li:ccct:t-<rsi^a.^^LHu. f -.fsiL-.
XCJX©--i= l Z<X<I<I<XL-£CJX©i-|i=.Z<I<X<X<X2Z:>rXZ:>:exZ©
•Gxinitflj^ccccii'utmxinrwJCiciiLCu-iETUTtTUTc
o a _i c.
Z©CE2Z©:E©t-CJI<IOZ
■’riu'tiEtnxtnuuJj
i>o- r in<rtis3Mj3
~3<r<T«-<r»rM*r<r«r
oooccococ©
O' © — r-4 M V 111 -0
<r in in it in in in
oocooooo
N X O O -1 CM r*3
Ifl in 3 -O C >0 <1
© © © © © © ©
<riiT'Orscooo»Hr-4ro^-in'OPscoi>>o»Hr-4M<T5T'orsooO'0’-tr-jr»3 l ^iiT'0( s 'CDO'
■O'O'O'O-c-crvr'-r^h.rsr^rvrvNrNmaocDCOomcDcocoooO'O'O'ChO'O'O-O'O'O-
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOjOOOOOO
o r i m <r
o o o c o
*r <r t <r <r
o o o o o
lil'ONCDO'O-
O O O O O ^ '
<r *r <r <r -r <r <
o o © © o o <
HI MI O h «
, H h h h rj fj rj
• m <r «r m <r *r <r
> © © o o o © ©
:'C3-«iL'.^li3N‘
'•'’^"ITn-TTTT -
i c* ci ri ci r, r, ci ci r-i :
5©oo©o©o©o<
i ui m i3 i*3 n » n r-i m n in r-i m *t ao r-i u m in <r ro 1 *?• © o<jCMn^-o<rr3n
) i *3 uj <ro«r<r©'C* , Lj <r o c m orouj <r o <r ro ©*<ruoo^-uj©
i r-i ro CD n uj r-J « o o n n is rj uj rj <r >o u. u. u. q cvi w * n uj rj| <r *o u. u. ti. u. uj rj -o ro uj n «o ro uj
jnuurmni , 3uonuiijrif3M' , )iijHHHur3uiijnMri"iu)HHri-Mtuouu.uouii.
3ChuiL©MUTCDiii©on'ON<uu.r-i<ri;‘)'ors«Qo*-i*T'olo‘UUJiLO*-«r4^-NO'UUJ»Hfn'0
3-o<3'Orsf^!\rsrvrxQococoa3a:cDOOO->i>o-i>chO<t«i<i<t|©©©©iXiJCia5iiiiiiiiiaiaiuuu
i cm n ci ci cm cm r i r-i r-i r-4 cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm r-i n| ri r-i r-i rj cm r-i r-i cm r-i cm r-4 r-i r-. r-4 r-i
>0©00©000©00©000©0000000©00 0©0©000©000©©0©0
CO 05 1=1 © r-4
CJ U CJ © Zi
r-4 r-4 r-4 r-4 r-4
o © o © ©
IfiNIUu-OC
mmSCuLII
cm r-i r-i ri r-i r-i c
© © o © o o <
oficz <r iJ <r Ci
r -4 x
r-i cj
: <c u h-
- - i=l <L
i 1 X 1 ill © <i r ;
X X iS | 2 X © h
: o © x <x x I w x o -xfM<rx c
I o - U •• L. | X © O - X » Ld
>x.=.coaizxx-ixi=i<r©*zxc
hX4N'-G£lNGGI
iZuZILOtZGt.
UHjimtMitrGij
J4CHU1 JOG Jii C © X <X © _i XX — €^«©«X-< XX_i-iX~iX>-i-X<E2<I-<NI©.-*2©-4_lX -NXOHOJii.1 -«NX©~.©_iX —
ix‘-xoioo<iONii=iOzc5o<t'Mzr©'-xQocizxN£z<c©z©z©f-L-cx4Xzox£ox©i:'Nxzzazc-a:z , NixzzozccxNix
jx(fljiJ££unj£Hj£unrt-)rcn_ij£j-«uTCJ*3UE^£ME03a3'3jj''Sj"5i:j-juTUTHtC£uunu'’~c<rrcuTU
.1 J£ - JEUT-
I|3 -O N CD O- O H, ri T L3 -0 N 03 O O H r-4 f3 «r ll3 -0 MD > O -* r-i M IT L3 -0 MU O- O w C-i « «C ||3 -O N CD 0- O H r-4 f*5 <r u3 -C N CD > O H fi M ^ L3 -O N 33 > O H n n -C i,' -o n'cO 0- O H ri n «T L3 -0 MO
^^!P^!0^^^^^^' c ' c ' 0 ' crxrsr ' rsrs,s - fvrs ' rs ' ,v ® c:0aDC0CC,CD::i:>CCC0a:,>!:> ' 0 ' Ch0 ' i> ' i>0,i:> ' >!::>::>ooo o©o©o-'^-’-i-''-i^--«-H-iririr4ririrjri ni ri .Mf^mrimmrom^M
n r-4 r-j r-4 r-4 r-i cm a r-4 r-i r-i r-i ri r-i ri ri ri rj r-i r-i r-i r-i r-i r-i r-i ri r-i cm r-4 r-i r-i r-4 r-i r-i r-4 m r-i r-i n m n n n rj n r,« m co n tro n w n m m « ro « «3 n ^ ro -i n « ^ w « r, m n m ro n
0©©000^©0000000©0000©©©©0©©0©©0©0©000©0©©0©©©0©00©0©©00©©0©0©©0©©0©0©0©0 0©©©0 0 0000©©
i ui ii. O H « fl N c a L. O ri "1 u3 I * J h « -c N C u Li H ^ 1,1 CD <1 a y L H f-i nj-0 >
)uuaacii5aac;05jiiJui5i'LUaii,iiLiLiLii.ii.iLOOooooooHHH l H-.
| H H H H H H H rt rl W r. H « W H H H rt rt H rt rl C4 r-J ri n r-1 M M T-i C'l Ci f'i C-J r-|
>00©0©©00©000000000000000 0 000©0©©00 0'00
flQ^n J .©rirn>OiM <x
h h ri :< r-i ci r -4 r -4
r-i r- ( r -4 cm cm r i ri r-i r-i
©o©©©©©©©
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
51
u
Ui !
© cj z x cj
u ' o U '
Z CJ £L Cl Cl
> ' ' O ' ' ' <
' u <r
*- g ►
o z x cn z x
Cl CJ » C X
JO' JL.
► -I <1 _J CJ 3
Z X z
Z N Z
c u a
cj o o cj a
05 CJ M
CO >-
: x a. j i a
Z 05 a cj
•> CD - *
x <x <r g Ly
x<ecx.j*iggcjqxxxxxxxxxxxxxx a.
*-* x «x o x
: <i ►-
J N k- 3
5 -! 05 Z
«*-•*-*
uZif
_ <X CJ -
x r> 3 :> x
< z o *i o a z
; *-* z u z z ^
^ -i x - coo
3 _i u_ <X X il)Ju.5X5X5X5XMXHXHXXJX«5
0<rCGCJN>3<I00ZC5Z0Z0Z3Z3Z3Z(JX;jG0
ruu.-u^CL-ja.t-.z-SMZ-iHZ-Z'-x^yjzi
© 0 - <
o o *
in in u
o o <
• in «0 fv 05 O' o
, H H H W H n
) in in in in in in
>000000
— n m <r in,
CM CM CM CM CM|
in in in m 1
• 0 r'*© 0 ' 0 -* Tim*? in - 0 r'-© 0 'O-< CM fO*- m ' 0 f^© 0 'O-H CM f* 5 *rtj‘ 5 'OfN© 0 '©-t nm
n n n n m w ^ m « n n m « « <r wt <r <r <r *r ^ <r ii 5 mi ijt ii 5 u 5 n in n iti -c < -c
in in in ii -5 iii in li "5 iii in in in in m in in in in in in in in in in in in in in in in in in in in in in in in in
00000000000000000000000000000000000000
V n MD O- O - n « «r „5 -o N CC O' O H r -i M ^ 111 -0 N 05 O' O rt 1
'O'C'C'O'O'CrvrNrNfs.r^isrvrNr^rvcccrcccxcDcccocDttcso'i
in m ii; in in in in in in in in in in in in in in in in in in in in in in in in ml
OOOOOOOOOOOOOOOOOOOOOOOOOOO Oi
Ul«OUIMOOOOolaO'OI‘)<tM 1
*? in o *? *r o in in in o t *r o m ci m r-j
<Iw<Cri' 0 C'CliJ €-0
nnunnmuiiU"
CO<IDliJli.CUKICI^li5-OlDI>CUllJlL^OHfJ<ni5(D&'<I<I<I<I€QlijH<r-00,iSQOn^M>«UuljHVnOJ5'
NNNNNQ)0DC0CDCDC0a3C0C0CD(Dt0a)|CM>CM>-a'0>lM5'0'(MMM>>!)'«<r<I«X<I<IlCiaOi£ianIiiCiiIifflUUUUU
mmmmmmmmmmmmmmmmmmimmmmmmmmmmmmmmmmmmmmmmmmmnmmmmmmmm
0000000000000000000000000000000000000000000000000000
u-c-OM-OMij5<i<iQ<rnujQoo'MiijQHca«inQrsofOHnriMM"’'Cn>oi
u. cj m rj m r -4 uj n m m cj m rx cj m m rj ix u uj m m u g cj g n r i rs r-j rs r-j h. cm m rj m i
rjn , rm < or^© 0 'au
.' UJ UJ UJ UJ
m m m m
<r-oo-iiiGoC'i«rr''.(>'<icjGu*-««rinco0'<xGuju.c*-><TincDO'UQO»H > ,,, , u , v ,. wv .
CCCCCOnliffiilifliaiitiiSaiUUunnuUUUCiaCuCluwCiUl'aJliJIiJUluuluJUUIUJlil
000000000 000000000000000
ui u. *-• r-j m *o rx <r|
luLuU.LU.u.u.ti .1
mmmmmmmm
ooooocoo*
Lu Uj
G 3
z <1
c cn
►h as
CD LLi<I
O X _i
Cl. H- _
*- >- aJ C
0022 )
J
a
U O it
3 <1 X
-J _l CJ
Sl. u. o z c
jXGGGOUJZGZZ>
_oic:
r - - CXXXX _i <
: ' cj x * g j n pi c ^ 3 o a - h- <z t-
' * _ cc - - cccuusuou: • cd ► x
.ZXXCDXXCJXZXXCJOOCGOGCGXXGXZCJC
; _j g z 1 a g
x 3 <r x
Z O h- z
- Z CD —
X <X -< t
CJ X G u. N :
x _i _j u “5 £
TT n -O p ' X J- O - r
ri CM rj .-.4 (M r-i r. m m r
*r*T<r«r*r*T*r*r*r*
oooooooooc
r i /5 >o n m > o - r,
; 15 15 M l', « <T <T «T
r*r*r*r»r*r*r*T«r
500000 0 00
r *5 ^ in -c
*T <r T *T
*? *r «r «r
OOOO
laZulZOlT, UNUNONUN
CD G
Cl II II
O
G - M
z
u * #
(S 05
'X<rz>xv--x<ioxu.
r 3 X u. <X ti
x <r o x u. ►
w'NCJNJ_;Z3ZGOZ3ZGOZX3ZOZXGZllN,XNJu_ k '3ZG!32Z
fi-)0-5fl-ZHJZHZHJZHTrHtHTj«u-;0TUntHjZHD
^ w iC^iC££iCXXN^JXXC
G2<I«X<E2CJ2ZZi=i02Z»=i
J-IirCCiCHQHW-JJtHHJ
O' O "
<r m ii
*r *r *
O O <
m w <r in o
1 in m m in
r *r *r *r *r
5 0 0 0 0
- x cJo
m mi >c
r < 3 - *r|«r
>o 6|0
>*■ *-> CJ
cc Ct a
"1 r i ^ ^ l *' ) *0 ^ 23 *>• ° ^ r J m m *o rx co O' o 1+ nm <r m -c n ® o» o ** c-i m in •« rs ©
O-C-C^'O'O'C'C-OrvixrN-'.rvrvrs.NNNcOcCCDCCCCCOCCCOCOCO'O'O'O'O-O'O-O'O'
ooooooooocoooooooooooooooooooooooooooo
0- O H M n T !/5 -O N
o>oooooooo
in in in in in m in in
000000000
in in in m
o 000
ro "5 in
o 00
■**5 n) m. o
o o o] UJ
m
o
in
o
o
nil ro rn n
00 00c
in m m in
o 000
U. N *4 O M- O' O
"5 5 1500 © O
■5 U r-j r*) X C C UJ <1 1/5 ii' iC fi 15 h h <! uj
ci N r-J uj r-i k) a. cj u a n u m g cj - u.
9-«au/ii.on<i(oiauaui«Nnvy5
^iUjLijuijjU.U.U.U.^.LLU.U.00000
r-j n r j n n n, r-j r j rj n rj n *i n 15 m 15
000000000000000000
o <r x) <r cj r j
*- O *r O' «r o-
■IN^ I5M c G <T G <1 G <1 G
U N h fl U 15 >5UI5U«UI5
NdBuwonn^m^ffNxacJu
OOCOOr-^^-i-H--.^,-,-,-/-,^
OOOOOOOOOCOOOOOOOO
<ri 00
-o rj
U CJ <X O « T N M H ^
CM <T O' Ci O'C’CJU'CCJ
oI
2 l
15 5 M>> CG
r j r j a c-t a a
151515 15 15 15
OOOOOO
f*5 O >*5
r-j m -■i
Uj Ll —<
rj rj m
D 15 15
OOO
<E
r-j
m
o
Nf5 15 -C >5 O »5 15 <1 •O ib C ill
n r-j cj w r-j n r-j u m ui 'i u u.
m -o r' « cj g m u. ri ud ix O' cj
M 5 Dnrofor* 5 f < 5 *n«r T<r*r«r
>5l5'5f5l5t5l5 , 5r5'5f5'5«
OOOOOOOOOOOOO
— 1 o o uj <ro<r
'CU'Or-j w O'©*?
<iui<r'C?n<rN!om-^<x
U u. U »1 fl “1 N M U -■ t*>
UI--M'0©O'CJQUJ*-i^-
*r m m in in in in in in c 'O
' 5 t 5 f 5 5 l 5 ' 5 r 5 r 5 f 5 r 5'5
ccoocoooooo
m
o
© G
fD -C
^U.LU.Uai5l5ri4M5l5«
N!><r«UGUJU.Or55li5'ON
'C'O'C-O'O'C'C'Oixrxfxfxrsrx
>5 5i5!5,5 p 5MI5l5l5f5l5'5l5
COOOOOOOOOOCOO
Page 42
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
52
I «
) * u ui in
5 - - - X
: z x z <r <x x
CQ u
z i z x z :
< X I _J X Z> _i
• X !_• I'JC <1
: x _i x r cj
x :> o _j x :
o x x o <r 2 c
r »-• x r cj m ;
ia.XLUXau<EC(L
ja<xuooasct;
< X t-H i-
> 2 O LlJ
: t-t z cc
i Z> Li- U U. > U. _i Z> Li
IQINZCCEN-ICIN 1
jiun'tu-njr.: —
n cd D- c w r-j m <: ii - ) <o n co o- o h (".j [<: -r iii >c n ® > o h r; ^ 'C n w i> o w ri n *r n >c >. co ^ o h r-j m 1
fXIXfXCOXXXXXXXXXCXCxO'CxOCXCXCXCXi>OCCO©OOOCO~^—C-i “iri r-il
••C'O'O'O'C'O'C'C'C'C'O'C'O'OJi'C'G'O'C-C'C'vorxrxrxrxrxfxrvrxixrvfxtxtxrxrxfxrxfxrxrxfs.fxfxrxl
00000000000000000000000000000000 ©0000000000000o.
- X X X X X
CJ J> U U I- U X ^ X -
ZGJTN'JSliJCU^ZU;
Tr UTiiOCxOrHCc
UaXAUL
i U A X I
■ X X _l
s <x o u :
J X I
• ► c
. X <X r-i
M_iXG>Ou.OOXX:
ox'j 00x0022:
XJOXX-xxr-tMs
<r ii* -o mb o o h rj fo t iii >o n co o> o r. : f n >c ■ ■ co i> o h to » n >c n cd O' 0
rj r. a c-i a ci
rx rs. ^ x. ix ix rx *x tx rv rx rs. x.. fv rx rx tx •, rx x. ix rs. <x rx r-> nnxxnnnnnnnn
OOCOOOOOOOOOOOOOOO OOOOO OO OOOOOOO OOOOO
in <r <r
00 0
in
o
LG *T
o o
in
o
LI
O
u © m to
<3- *T <3 f
X O
<3- r-i
c
o Ci o ci
ox o
cm u_
-1 m
o ^
o
r-i
-0W»-Iffl<IOO«’-ii£iw«O!CiHM5-C'0'C0>
M r-4 LU r-i Ui rx r_j |X r -4 fx fx CJ r-4 N C-i !X a n r-i m 0
uj ci ci in r-4 n r j n s u a u n a u o c: x
<r •■. w5<IC-J.-A'0tM).
Cj'iZi !X (Si CJ O UI CJ UJ Ci n Cl CJ
<r Si <r =i m
r-i a <r <r rj
amt*)M'Oujuc»iiJUJXfnujiij
<r o ci c-i - rx u. u ^ Xu. u rj r-.. u
tM> o- »■ 1 u a o h f J ti -c n a
rp 111 cf i pi m rn rfi 3 s ^ 3 * O' ^ O' O'
<T<T'T'?'?<T<?<? r T<T*t<TT'r
OOOOOOOOOOOOOO
O' CJ a Ui LL
Os O O' O O’
•3- <t <r <r -?
OOOOO
o 1 n t '•
<XC<E<X<T<I
<T<r*?<T<r<r
000000
rx ?v rx cc a, cj a;
<X<I<E<I<X<X<X
<r <r <r «r <r <? <r
OOOOOOO
ui u r -i to
X C A A
T <f <r <T
0000
<r \ a ui u. r-; cn x o-
A A A A A A U U J U
<T*T<TT<T<T<r^- r TT
OOOOOO OOOO
o
<r
o
-< r-i in x o- <x a cj u
a amAuaaaa
*t <r<T<r<r<T*T<T<r
OOOOOOOOO
U O O
a uj ui
«r «r <r
000
o o r-4 in <o
Ui Ui UJ LU Ui
<r <r <r «r <r
OOOOO
rx x uj cj a ui
Ui UJ lu Ui UJ UJ
t *? <f <r <r *r
OOOOOO
UO X O'- <x
U U u. u
<T <r T <3
OOOO
U U C <H
uuoo
<3 *r ui in
OOOO
XM<EXMX^<Xhh;
uzacjzugzg;
wlJOTuEHXt
• E> X X 1 -t _J u. I-. 5
. UOXOXCC©:
)~XTu.JCJ£lX‘ i
: tx h x _i i _i x c
: z x> 2 x cj x cj :
i IE H 0 X 01 X '
>GHi£CC UliHH H > I- li H CC X U- <1 H-
] 0 ZAA-I<IullUQ 01 iJZXUNZE |0 1 iJ
[ECitltAiE^Ln^EAHjQlwIJA
j HH x •-< *-<
: o 2 o o
j x >-< r x
AXNH)
UZZGi
O *-« ~5 X ►
r-j ?<i <r lp fx a? O' c <h rj rn <r ut -c rx x cs o cj ro <r ut -o rs x o- o •" ri r<i <r lt <c !x x 0- c r-4 ro <r ii"5 >o rx 00 os o <-< r-i tn <r ut >o fx 00 cx o <h rj n <r ut <o rx, x ex o -m r-4 tn <r LG <0 rx x cx o th ri tn <r ij - ) >o
o. £»• a- O' o- o »■ o- o o o o o c o o o o h w h w h h 1 - h ts r-i m r-j ri ri r-i r-i r-j r-i r-i n tn m n pi n m « « « <r <r <r <r <r <r <r c <r <ni mi lii lii lii lii n n i3 >o <1 -o <1 -o >o >o >o -o <0 n n n n x x n
illu'L'li*li3LTIill''C'0'<3'0'0'0'0'C'0'0'C'0'C'0-0'0'0'C-'0'-C'0'C!'C'C'0'Os3'0'0'C'0'0'0'0'0'0'0'0'0 - C'i3'0'0'0'0'0'0'0'0'0'0'<J'0'<J'0'0'0'0'0'0'0'<l'0'0'0'0'0’C'0'0'0'0'0'0'0’0'0
000000000000000000000000000000 00000000000000000000000000000000000 o| 0000000000000000000
«T lii
o o
<r <3 <3 <3- ui ©
O OOOOO
in
o
in
o
in
o
sQ M >0 UJ O O
-* *r r-i c-i r-i r-i
O' iil U COQ
Ui r-i rx r J r-i r-i
•o a fx 0 <x
-< o n- «r w
u. o <1 u. rx o
o m m <r o u.
o <1 o rx
nn-oo
O UJ >o|
y-t SO *0
rx o <r o
r-i o m
x o o rx
rx r-i r-i -<r
a r-i <i q r-i is >o m sc m sd m c uj
m o to m cj r-i tn r -4 w a to r-i —* u
c <r uj r-i uj <1 n « ui
UwU AUQNUA
-c « « IT r-i -o n r i su r-i a tn
^ r-i r< o u n r-i Ci uj r-i u cj
rx'O'OUi-C'OuX'O
3UiUUAU<rMii
U' 0 UJC' 0 rx 0 'Cj-<<Q<ifntn'<r 0 '
HuuauvuMrtnuHUHU
<I'C!<1Ui'0QMr-i'0M'0!<5('J0'
N M N N !1 !<! W U M C i m r-i r-i u
U CJ
n m
o o
Ur-4M'CM><XuAUOr<K)'ONO'Ulii-irii1'C»'UAUO
l o o o o o o o o o « h h w h h rt rt r-i r-i r-i r-i r-i r-i r-i r-i tn
tn<T<r<r<r<r<T<T*3-<T<T«T<r*3-*3-*T<T<T*T*T<T<T<r<T<TX-<T
000000000000000000000000000
^ r-i iil N A A U U
mfofnmrommm
*TT*r<3-<r«r<T*T
OOOOOOOC
OWflMM-r-OACA
<T-<r<r<T<f<T'<r<r<T<T
'T'T<r<T<r»?-<r<r<r<j-
0000000000
u o »-<
«t ut in
<t <r <r
OOO
m «r iii so rx
\n ui m ui in
<r <r <r <r <r
OOOOO
CX 1 X 1
lil UI
«r <r
o o
uj o rt r-i
Ul sO so so
OOOO
tn rx
OOO
<x cq'u
<o <OI<C
<r <r|<r
o 00
u o o o o
>o rx rx rx tx
<r <r <r <r <r
OOOOO
m ui -c x <e ixt cj u ^ rj <r
txrxfxrxrxrxixrxcoxx
<r<T<T<r<r<r<r<r<r3<r
00000000000
n x
x x
< 3 - < 3 -
O O
Number 21
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 43
53
i X >— X X
. 'I 05 <t 3
o r*5 w • o n ro ' '
o o r-j • oopi'
wuuuuuuuuuauuuu
o; xaa;o5»iasc^a4ii.ac.o5sajio‘*ia^aai»oTi2i 1 5i5xai*ii 1 c^iXi*f/)ii l aia4y5iaJ5ai05iii 1 iiiXi05iaiiiiii05iricaiiio:fliiBi3icni3iCQ
*-• CwC<ruuw«uuC<iflwu<iHuw<iciaw<:aau'iflaM«Mua<rflflQCQuu<:i3Cia«aaa<iQOfi<iaafl«pM
01
iMIIiDXXl
u<rQ3u<Iuu
o T-t r-i ro u" < ‘v cc cp o — rj pn t n >c P' a: s> o -- rj n <r ut >o n cd 0 * o «h rj n *r iii >o rv oo i> o ^ rj r*i *r ut -o rs 03 a- o -h r-j r*i «r ut >o rx a) i> o ^ r-j to ^ bo, >o n 03 £► o rj m
Pi PJ P< PJ Pi j Ti rj Ti Pi f*l « M M M ro rj « fO -T ? <r C T C C «T <T ill ul lil tl lil tl ill 1,1 111 L5 -0 -0 -O <1 -0 >0 -O -0 -0 <1 N N N N N N N N N MB CO CD CD CO col CO CD C0 CD 5- 0> O O
CCCOCDCDCDCDCOCCCGCDCCCDCCCCCOCSCOCDCCiCDCDCDCOCOCOCOCCCOCOCOCDCDCCCOCDCOCOCOCOCOCOCDCOCOCOCOCOCOCDCDGDCDCOCDCOCOCOCOCOCDCOCOCDCDOOCOCOCOCOCOCOCCCDCC
ooooooooooooooooooooooooooooooooocooooooooooooooooooooooooooooooooioooooooo
I
i - o uj fj h o -o n n o uj Pi o n h <r o -o h o uj Pi oo o -o ^ u. o Ijj pj n o n h n o il 1 -* pj o n h pi o i
i®uc<rouo<rcaouiOi=iOuiocio«TOujc<rououi030*-030<ro©ouiooouio-<©Lio«
oh.*, rO'0f''C00-uciLju.cNn<rL')C00'<i.xiujL.o^^in'0N«aiijCiO^rjn-or^cD0'Cj!:
"jCMJ-aO'Ciuii.CHfn'i'flMcuuUu.'O'rbi'O'iaui: _ _ _ _ _ ___
,.u,UiiiUUiiiiiiJ^LiLii.LtHtLu.itiLiiOoooooooHHWH h - h w ^ h « pj n rli pkj r-i n rj cm pj w n n fi w h n w n m v ^ <t v Vi «r ^ t «r <t in' Li
.1 Ul Ll Ul ul U* Ul i.! Ul Ul Ul Ul Ul l! Ul Ul Ll U1 HI Ul -<3 >C 'O 'O S3 O O ~0 -0 -O O -O C 'C ~C 'O S3 S3 S3 S3 -O S3 S3 S3 >0 O -O S3 S3 S) S) S3 -O 'O >0 *0 S) S3 S3 S) <3 -<3 >0 >0 S3 'O' S3 *0 S3 -<3 ss s> -o sj
gooooooooooooooooooocooooooooooocooooocooooooocooooooooooooocooooooococooo
3 U. UJ <
« u. ic c
<ICuC
J * i .
uj <r u_
C O “3
CO (J 01 c
Z O Ui
H JO-
- iZ 3
3 3 a. UJ 05 01
3 O >- I O O
. 03 I— LL U_
i 3 01 III 01
cl cc a h-
C ll CJ
2 CCilCuJ
it lC G “1
3 LU 3 a
p- 3 2 0
UJ CC 2 »-<
liO" 2 U.
3 2 2 O
CD 2 M
touHisa
_ X CD 3 2
ICuiSU
05 iXi
X X I, I X
iXXXXXwl'OOO
JCDOmOCDUCiQIUJU.
• h n PI M M o o o' c o
-CQ3U.U.U. ►
© 03 3 3 3 5
_ - UJ _J 3 3 3 l
o o o' o o o o pi -i r; Pi o o o o o c o n o c cc a a c ■
U-iL£XiLiCG«u.<IilNa:u.
2322X2CKrxr22X
itHHiHtinixLnHT
-h c-i m -r u3 -o p. co O' o cj ro <r ui -c rs. co
'O-O'O'C'O'O'C'O'Orsrvr'rsrprvrsixrp
i\rprNrsrvrprprvr^r^Psrprvrsiv»Nrprp
oooooooooooooooooo
3 3 3 3 3 « U
lMfiS3CCaiiS3u;GaG32uC5
luuwuuCLJUjuiUjJ
G JIl J
cu-u.cn
3 3 3 2
Ll_ iXi CQ •_
o u c
3 O C
* 3 .
<1 K C
a
u
. 05 I-
i a: o _j
5 U 3 O 3 U *-
J003X20C.C01
:33iC3 - Z32
i Cl <1 UJ * Cl Ui G h
0-OrtPJM<TlilX3NCD|0-0'-iriMVIil'OPGI)>OHriNl«yl'ON(I!!>0-
NCDCDCDCDCDCDCDCDCDlCOCPCPCPCPCPO'O'O'CPO-OOOOOOOOOO'^-'
!^^!^ rsrv|vrs - rs,SNrvr ' r ^ rvrNr ^ ,s ' N, ^ , ^ r ' sCDCOC3COC 3® | 23®rocDCDx
000000000 0|00000©0000©0©0000000000
«r -r *r *r •? -r in <r
• til r-i <r «r r-i
rO S3 CO CP <1 Ci 3
o o o o o o o
ui ui li ui ui m in
© o o o o o o
U.On<rii 5 ffi(PUUt
in Hi n ui ui ui in ui ui u
OOGOOOOOOC
*?■ ui -0 rs
cm cj cj cm
iii iii ui in
o o o o
cd o co a cp ai 3
pj m n cj a a u
CD CP <1 l& CJ m 3
r-j r-i r-j cj cj c-ji cj
L l Ul Ul 111 111 111! LI
0 0 0 0 0 0,0
' Ul IN
Ll %
30—iCJ«r-XU33OCJr0«TUlfSCP0-0'0'0'D'<I
cil*linni*)i-iin! , lin^<r-rT<T<rt'r<fT'rT<r
in ui in ui ui ui ui ui ui ui ui ui ui ui in ui in ui ui in ui ui
OOOOOOOOOOOOOOOOOOOOOO
O > Ul L
*3 I* 1 . T <
O S3 D PI L
rs rv
Ul Ul
o o
Page 44
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
54
oxcni'i- x x x x m- it it i ^ ci u oa cx<rx<ri<xiCL o
<r in x -• o i <r ci o - rx cn u z :> x x a x a x x x a o z a a: o z co z x c x
XCiOi.UCLOCJOOItJCtUCC Ci »-i ZCOC<tCO«OCna)CO'C<I«XiIiO «CJOXCO
O- r-i • OO-H O © ->-< ■ OHOOfl' COW' O O ' OOT-t' OfiHx O «T *-« ' O -O' CM ' O W c GD rt O O " ' OCS-^' C O- H • C © ' O O ' © © ^ o O — © CM -< • © “i
CJ Li U O U O O O O I U L> CJ CJ CJ CJ U U U U
Xfiiri£CCCnSAfi01CfiCC£^CSAlOCASU)fiiSAO^AASCf>CACCOCA|CUjA£CiSC^i3A>>iUiiiCiiXii£U)i9AiIi(niSAXO'!iXiAi£'RCiZiACOfii4i!£En3ACu;CaCi)
Qu<raco<iciMM<iuCiuQui<iwaM<iuuo<:wwu<ioau<iiaQM<iua|w<iaciaaa<iuQCi<rui3u<iQuw<iQca<iawM<iQCiw<rjOuCQCQ<TaQ
o- c h rj n c n -o ms >
NCOCOCCCOCOCOCCCCCDCO
D > ^ Q* O' O' O' O' ^ O'
OCOOCOOOCCO
o cm w ^ ld -c rx co o- o »-* ci w v in -o ix cd o- o cm w in -o rx. as o- o *-< r-i w *r in -c rx co o- o «-i r-i w <r in -o rx co o- o th c-i w «r in -o rx co o- © --i ci w -r in -o rx co o-
o,j. O' o- O' o o i> o- o> o o o o o o o o o o h w h h h - h hIh h n m m ci n n r-i r-i m r-i « « m m "I n w k ■o m <r <r <r <r <r <r <r t <r t n iii fi n n n fi n nn
O-O'O'O'O'O'O'O'O'O'OOOOCOOOOOOOOOCOOOOOCCOOOOOOCOCCCCOCCCOOCOOOOOCCOOOOOOOOOOOO
iucujriW’ri 1 'icDi><riiiuciUJij.o^riw<ruT'OfxcoO'UCiUjij.r-iw«ruTCDO' , <:aiUjLi.CT-iriro'CixcDO'UCiLiJU.rjW'«»-iiDXO'*xiiiLiJLLO'-i«riiD'0'x<x*ucio--'
iCCQUJUiUJuJUjUjUJuJUJUJUuu.u.L.u.Li.L.u.Li.u.u.u.L.u.u.oooooo|OCOO-4rH-t T H-4r-i.^TH^^^-Hr'irjc-4ricir'iriC'iciC'iwwwwwwwww,'nT'r
)'0'0'0'C'0'0'0'0'0'0'0'0'G'0'0'0'0'0'e'C'0'0'0'0'0'0'0'0'OrxNNNXNlXNNNNrxi'''r'.rxKXIxr'.!'', rxNNlNf'f'. r''Nrxr''NXN|XN N!''.!''.f''Nr'.r'N f'.
^OCOOOCOOOCOCOCOOOOOOOOOOOCOOOOOOOOOOOCOOOOOOOOOOOOOOOOOCOOOOOOOOOOOOOOOOO
Ci W -OfXCi
«r <y *r <r
NN x fX LLl
O O O O it
5 Ci ^ - C W »
COW' o c -
O O CM ' C O CM '
i a a ci a c a x c a C ji i
CJ Cjj
01 fi is fi L0 C
I
T ID 'C N CO O' C h Ci 1*1 C III <1 N CO 0 C h C-i M ^ liT -C X CC O' C h C-i K ^ 11 -0 N CO O' O h M !<; ? tl "O N Cu O' O -4 Ci I*) V t' -C N CO O' C J f-j ^ ^ lil ‘ij [\ 0! O' O f i W *T LI •C N 03 O' C Ci
»• 0 0 - 0 0 - O' c c o o c o o o c c h rt h rt H rt h h ri n m r-i N n n m r-i r-i w n n k n « w n w w ^ «r <r 7 ■? -r t « t -r lii mini in in m in li in in -o -o -g -o -g -<3 so g -c -o r-~ ?x r-.
COCOCOOOCOCDO'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'OO'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O-O'O'O'O'O'O'O'O'O' 0-1 O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O-O'O'O'
00000000000000000000000c.000000000000000000000000000000000 0|000 0 00000000000000000
L) CJ U CJ i CD CD
*T Ifi CO O' <
in in if) in i;
G G 'O -0 '
o o o o <
i U U. O -rt T m
: in li g g g g
j g g g g -c g
>000000
g rx <c iii u
G G <3 C G
G G G G G
o o o o o
■CNN
-o-o-o
o o o
cm w rx co O' <i
X N N N f> N
-0-0-0 G -0 o
o o o o o o
C, Li u. O
rx rx rv CO
•o -o -o -o
coco
t in -c
CC CO CE
© c ©
rx a; c
CD CD C
G -c -■
y
> G -t col
> fx O 'T
o O' <r|
4WW-WW'U'U-WU'U'U'V>U'U'iU>iM^'£^ <C|'*
2GGGGGGGGGGGGGG CGGGGGGHG
>00000000000000000 00 0 0*0
I
i
LiLl.OW'TLD'CrxCO
Cissccaaia
GGGGOGGGG
oooooooooo
a c a. Ci
-c -C -o -o
o o o o
W <? If) -0 O' C Ci
'J U U U U J u
g g g g g g -o
o o o o o o o
UL - cm m
CJ O c Ci Cl Ci
-0 -O -O -0 -o -o
o o o o o o
Number 21
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
55
* i—< x <r
J o c
x 2 l.
<t c/3 :
2 X .
< IX . ' — * £
■ <x x g co £6 cn
j x x cn x <r x c
; x cn x >- f— >- :
. o o w — r: «r ?
J J J (J U C.' U I
i X © O O TOC
<x 2 c
-J Q !
X X 2 2 2
75 X X O C
X X X £- H-
x cj <r <r <
x £- co cj u
o u g c i
<r uj
G ££ I
2 <r *- >- 2
*-* X X LU
2 U 2 O UJ
2 0 2 0:
w X UJ CJ
CD I H- 2 7)
UJ f- f*
_j _j uj 2 <r u
X I X X
2 u. o <r o
X t-H w o O O
: o <i ouoco
' X CD 2 G G G X
C O <1 tw o o o o
-J -J
HDjHJ5iS:<auiXj:Nu.GGG3GGG
U50€5«0 3GaZQ2J22000 OOOO
1 2 2 'J 2 G 2 CD 2 75 O X w X ~3 ~5 UJ LU U X UJ X X
_J _J
<r >— i— ’—> *—< —i —j w w
X G 3 X X <X 1 Ni 2 Cl ‘
XCC2J_IUCJ-<tCJ-
Xr-^QXu.
U X <E U 2
X _! |=| X ~1
HOOXXO>-tNu.333X
(C0220u.220C3a
JJ2hh2UGGUJUJuJIiI
-0NG0'O-'rj^<fl/)'CNCD0'O'Hf'iM<Tli5
ri n rujio ro n m « n m m n w ^ «r <f t -r
oooooooooooooooooooo
oooooooooooooooooooo
O CJ _
o cn x
DC CL CJ
-ON®
«r <r <r
o o o
o o o
****** 2 t-i * * * - * * * Cl <r ooito
-h c j f*5 in >o n a/ > o ^ r j n <r liD *c co O' o r j r*5 «r JG >o ix 03 o ^ r-J ro ^ tin -o rs cn ch o t-i n ro <r n >o ^ co o* o
o o o o o o o o o - - h - d h n w - - m m fKi tr; m di m m m m n tin n m n ^ t f <r t <r -t t </
OOOOOOOOO© DOODOCOO ©OOOOOOCCOOOOOOOOCOOOOOOOOOOOOCO
©oocoooooooooooooooooooooooooooooooooooooooooooooo
o
o
o o
g g
CO o o o c
u. o o u o
o o o o
o c o o
o o
r-j o
u
CJ
o
o
o
o
<t X O' O O' O' <TCN
Ci CM h M -i CJ wo
UJCDOOO'U.UJl_Ci*TO'CjNiZi<X'OjJ
U-cjoo'o — or'woorjwowfxo
o
©
O'
r*3
o
o
o a uj
x ro o
■cujr''Q'0iwCi*5cj<xr-;~i
ci^^roocjrso-rNO'Ciu
x r-4 «r g co <r x x x © w <r
W 04 04 04 04 04 04 0-4 04 03 fO 03
oooooooooooo
©o©©oooooooo
MflNM
04 O CJ U
>-
ii3-oo<ioaaacii3Qq
mromrxm^3fxr*3fDf*3^c
OOOOOOOOOOOX
©oooooooooox
xmr<3w,-ixx«'0X<rx<EX<rx<r
Cu-iOrtUUUwLUkUdowU
£0
UJ
O'iX'n £D o* £Ci w<rrso3rouujo4r*3
w UJ CJ UJ O UJ 04 h N ri M Ml (J U
OOOOOOOW
oooooooo
o o o o o o o o
oooooooo
M 111 CC C6 J rt T
C O O C O — —I
O O o o o o o
o o o o o o o
"0 CO CD Ci O 04 if)
W w w w O. 04 04
o c o o o o o
o o o o o o o
n cc a a c uj
04 04 04 04 04 04 04
o o o o o o o
o o o o o o o
w 04 03 -c 'O O. CD
03 Xi !^3 CO 03 rO f*3
o o o o o o o
o o o o o o o
O'O'UXXXOw
rofororofoco'ro-
oooooooo
oooooooo
ro 'O a- O' O' 0 - ci
<T *T T <? *T <T <X
O O O O O O UJ
O O O O O O X
cn cd
CO X
<X X
2 C 2 2
u cd :
<r '
j x cn
: o u
- x <r
— x
- 2 <Z
4 O X
X 2 O O 2
< X _i w I _1
3 ► ► 2 * »
. I S Jh ft u £
w _j x z> r>u o o x x xw r» w xr>-
OXCJ0 0 2G3022200XNJCC
2_iQ22-?22w-ii-irrcj-;Q2C
J U LL H 1 i
<ulXCOQ2DX.
li 03 O
cn c/3 cj
CD CD <X UJ
(-OXOO CD
UJ H- UJ ii O <1 O
cD052<r#ou.a
XD>wCJwiXXXXO<rx<E
Ni2CX2D»22 2 2G l -2X
-)HtuniKH-!-£inx
X X
C l m W
X X Ci o
X O >0 o
u o uj a
I ItU JO o
X N4 X X 3 a
2 2 2 2 3 X
UTHG UJ
CD <T
> O X
X _4 O
O O X
2 CD X
X O
2 2 CJ
2 2 G X
X w 2 u:
_l •- X X
<iDca
©ox
X 2 X
x cn 2
h O C/3 O
U X CJ
CD O O V
<r xx
2 W ,x UJ
DCONH
x x O' x
£5X2
X X CD
2 m w
w X X
f- w >
XXX
o o c
X 2 CJ
X C/3 X CD
»- X 2
CD 2 X
CD X h O
XXX CJ
x <r x
x x x x x
X 03 X CJ X
■C X X
X x<li>
H X CD X D>
X X X t— X
X £- X X O
*- O X I- D> Cl
X 2 C X O
G C O CD cn
X CD X W 2 X 3 '
X X O ► ► 0 3
♦ G<xa,G<r£Dr«x<
x >■
<t
2 X
XXX GXXX X
xcnxxxxxxwocnwcjwt-i
<X3<I0GC<I<X0G3X20X
GXGXXUOU22XG-32G
00
H "i 1<) <r 111 ■fl N a 3 O rt r-i M ^ 1(3 \ 3 I), o -> r-1 13 <r a3 <! N (E o. o rt n v J M33 o. o
OOOOOOOOCww —i w —< i —i —. —; w ' 4 ■'•■4 IN C-4 r-4 r-J ,'•< '•< Ci 04 M I3 !3 43 (3 f) !3 N M ^
OOOOOOOOOOOOOOOOOOOOOOOCOOOO OOOOOOOOOOOO
oooooooooooooooooooooooooooooooooooooooo
w r-4 m t m >c
<r <r <r «r <r <r
o o o o o o
o o o o o o
« 13 ? ii3 M3 MS l> O H ri f3 ^ Ii3 -O MS 0- O rt N 13 ^ Ii3
O O O O O O O O O W w w w w w w w w w r-4 C4 r-4 r-4 r 4 r-4
OOOOOOOOOOOOOOOOOOOO OOOOO
ooooooooooooooooooooooooo
o o
X o
O UX O
O O W
o
o
o
o
o
CD
r -4
o
o
r-4
O '0 o
o x o
X ID X
O Q O
r-4 ro <r
U CJ CJ
O' CO M3 O
X X O w
O O O O O O O O O r-4 ii3
ooooooooooo
© o o o o o o o o o o
oo©oooooooo
«rXK3*TX**3^-'D'DXX<XXXX<X
f <r (J <r ? o r-4 w rv x cj r-4 n x cj
m! Nffl 3 U a UJ u. O r-j <0 i'. 3 O- •! U
OOOOOOOOwww—i—<ww—i
OOOOOOOOOOOO OO 0-0
ooooooooooooooo o
Wliiuif-iM3f3f3<f «MI3U.a r-4 CJ f<3
r 4 m x x m w r m x w rv o g <r * g w a
>-
liOHN3 -O G O' <r X X X O :'3 <T fcD CD O' G G X
— r 'i r-j r -4 r -4 "i m r -4 r -4 r-j MWrtiDMttnwnc
oooocoooooooooooooox
oooooooooooo©OOOOOox
a ill x w a x x x x x un x r -4 x x
GXGXXGGGOr'GXXfDX
OOOOOOOOOOON<TN!3Mlk.3;^t* i C“Oiu
OOOOOOOOOOOOOOOOOOwwww-1 — w
OOOOOOOOOOOOOOOOOOOOOOOOO
OOOOOOOOOOOOOOOOOOOOOOOOO
Page 46
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 21
56
dr dobbs journal of
COMPUTER
(Calisthenics Orthodontia
Running Light Without Overbyte
Number 22 February 1978 Volume 3, Issue 2
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
ET TU, KLATU?, Stanford News Service 4
Quasar Industries’robot called “a fraud” by John McCarthy
The Last Rehash of Beau Hex? letters in the unending/?) hex/octal debate 45
6502 SOFTWARE
Decoding Efficiency & Speed: Pros & Cons of Table Look-up, H.T. Gordon 5
8080 & Z-80 SOFTWARE
MITS 4.0/4.1 BASIC Searcher/Patcher, James Monagan 8
Z-80 RAM Tester, John MacDougall 42
Mini Editor for 8080 PILOT, Tim Scully 43
CODE RELOCATION
A Simple Technique for Static Relocation of Absolute Machine Code, Gary A. Kildall 10
the creator of PL/M and CP/M tells how
Relocation is Not Just Moving Programs, Richard L. Roth 14
TV DAZZLER SOFTWARE
PCC’s Dazzler Contest Winners (at long, long last), Robert B. Jacobsen, Exec. Dir., PCC 21
Absolutely Dazzling Dazzleware, Gordon French & Gregory Yob 22
Dazzler Driver Subroutine and a “Chase”, Phillip Simpson 30
MORE GOOD ADVICE ON MAIL ORDERING
Gentlemen: Received: 78 Jan 24
In regard to your recent article on slow or non-existent
delivery on the part of some merchandisers in the home com¬
puter field, I’ve devised some defensive techniques that work
well.
Always write a letter in advance asking if the product is
available for immediate delivery provided that a certified
check or money order is sent.
If you receive no reply, don’t send in an order. If you are
really anxious to purchase the product, you might try a
follow-up letter just in case the first one got lost somewhere
along the way. If you still hear nothing, forget it.
Once you have received a letter indicating that the product
is available, send in your order with certified check or money
order. Keep a copy of the dated letter and also photocopy the
check. In your cover letter clearly state that you wish ship¬
ment within 2 weeks (or whatever time you feel is reasonable).
Otherwise you want your money refunded.
If you do not receive the product on time, send a follow¬
up letter. Courteously remind the merchandiser that shipment
by a certain date had been promised, and refer to your
previous correspondence by date. Keep a copy of this letter
also.
If you do not receive a reply within two, weeks, send a not-
so-courteous letter by certified mail, return receipt requested
(costs about a dollar). Tell the supplier that you want an
immediate refund or you will report the matter to the U.S.
Postal Service, the Attorney General of your state, and to the
magazine in which the advertisement appeared. Keep a number
of copies of this letter, along with the signed delivery receipt.
Wait another two weeks, and, if you still have not received
the product or a refund, proceed to report the matter to the
U.S. Postal Service, Attorney General, etc. Send copies of
correspondence with the merchandiser. Send the merchandiser
copies of your complaint letters. You might also send copies
to the Better Business Bureau in the merchandiser’s home
town.
If the above sounds like it was written by a paranoid, I can
only claim long and bitter experience. My method works so
long as the supplier is not an out and out fraud. Before sending
a really substantial check, I would ask the supplier for credit
references, if I was at all dubious.
It is also extremely effective to send complaints to the
supplier’s bank (appears on the back of the cancelled check
if deposited) and to credit rating bureaus, as well as the whole¬
salers he deals with, if known. These are effective measures in
drastic cases.
Sincerely, Berme Rd
John D. Hirsch Kerhonkson, NY 12446
RASKIN JOINS APPLE: LEAVES DR. DOBB'S
Announcement Dated: 78 Jan 18
Jef Raskin has been our itenerant product evaluator for
some time. Part of the reason he could do that is that he was
an independent (very) computer consultant. He has recently
taken a position as Director of Publications with Apple Com¬
puters of Cupertino, California. As such, he can no longer be
considered to be “independent.” Therefore, he will no longer
be submitting “product evaluations” to DDJ. It is likely,
however, that we will—from time to time—publish “product
opinions” authored by Jef.
O TEMPORA, O MORES!
Vector Graphic Inc.
790 Hampshire Road, A-B
Westlake Village, CA 91361
Dear Vector Received: 78 Jan 30
You are without a doubt the most sneaky, conniving com¬
pany I have had to deal with in the microprocessor field. It is
disgusting.
My letter to you, written (and clearly dated!) 22 January,
1978 (a Sunday) was not mailed until 23 January 1978. Yet
you managed to somehow get ahold of it on the 24th and get
your reply into my hands by 2 PM on the 25th, a gap of al¬
most 4 whole days! What’s more, the material promised by
you did not arrive until the 26th, 2 whole days later, which
was exactly as promised!
Now my request was fairly reasonable and should have been
simple to answer. But oh no! you have to set someone down
who completely understood my request, have them answer my
letter specifically point by point and then cause them to mail
the answer without cramming the envelope with useless and
unrequested literature.
Well let me tell you people up there at Vector that while I
may have appeared to be a mild mannered computer hobbyist
working for a Great Metropolitan Newspaper, I am in fact, a
systems analyst with more than 20 years experience in all as¬
pects of data processing... And I’m not going to stand still for
conduct like yours!
If I can write to MITS, Micropolis, Digital Group and Dyna-
Byte and never receive any reply at all, and if IMSAI and Poly
Morphic and Space Byte need from thirty to ninety days to
get a bale of unwanted literature to me instead of an answer to
a specific question, then the obvious question to me is
WHAT’S WRONG WITH YOU PEOPLE UP THERE?
Don’t you people realize that a response like I received is
like waving a yellow flag in front of a gorilla? You may think
you have the world by the toe-nails and can afford to trifle
with guys like me but you’ve made a serious mistake this time.
I’m really going to give you the business!
A copy of this letter is going directly to Tom Williams at
Dr. Dobb’s Journal. There is no doubt in my mind that Tom
will publish the letter and let everyone know just what kind of
shenanigans you guys are up to!
Acryptically yours
Robert S. Hoover
First Heath returns phone calls, now Vector Graphic answers
letters. What is this world coming to? -TRW
SOLUS PREPARES SOFTWARE DIRECTORY
News Release 78: Jan 29
The SOL Users’ Society (SOLUS) is preparing a directory
of programs that are tailored to run under the SOLOS and
CUTER operating systems. The list will be published in the
SOLUS Newsletter (at no charge to the software vendors).
To qualify for listing in the directory, a program must be
compatible with both SOLOS and CUTER and be available on
CUTS format or Kansas City standard cassettes. It must be
well-documented for the user, extensively tested and
debugged, and supported by a warranty to repair or replace for
at least 3 months. Programs written in higher-level languages
will be accepted if the interpreter meets these specifications.
Software vendors should send a brief description and order¬
ing information to SOLUS NEWS, Box 23471, San Jose, CA
95153.
Number 22 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 3
59
ET TU, KLATU?
Stanford University News Release Received: 77 Nov 14
A company which claims it is ready to manufacture and sell
truly intelligent household androids, or robots, within the next
two years—to the tune of $4,000 apiece—has the nation’s
artificial intelligence experts up in arms. The experts
unanimously state that the claims are fraudulent. The com¬
pany, Quasar Industries located in Rutherford, NJ, is currently
touring shopping centers around the country with a model of
an android which they claim comprehends 4,000 words of
vocabulary and can vacuum, wash dishes, and teach the kids
French. Crowds in the sundry department stores are dazzled,
according to numerous press reports. This robot is a fake,
according to scientists from Carnegie-Mellon University in
Pittsburgh, PA. The scientists recently undetook a first-hand
investigation of the matter and found the robot to be a
“radio-controlled puppet.”
Quasar Industries sees it differently. “We programmed the
robot to approximate human behavior,” said Anthony
Reichelt, president of the company. “The only limitations to
what it can do is the boundary of imigination and the cost
factor.” Quasar Industries has no relationship with a brand of
television set formerly manufactured by Motorola and now
made by a Japanese company.
Numerous publications, including Newsweek, Parade, and
Newsday, have in recent months printed articles about the
robot—called Sam Strugglegear—in which the claims made by
Quasar Industries are reported as fact. “It is a fraud that has
gone on far too long,” says John McCarthy, director of
Stanford University’s Artificial Intelligence Laboratory.
McCarthy is one of the earliest pioneers in the field. The
technology is nowhere near being able to manufacture a
robot which can do all, let alone safely, what Strugglegear’s
owners say it can do, McCarthy said in an interview. The
company has some sort of expensive, remote-controlled
gimmick, he said, which in no way possesses the sort of
intelligence claimed for it. “The press has been extra¬
ordinarily irresponsible in not bothering to ask the opinion
of artificial intelligence experts on the matter. They don’t
have to believe us, but they should at least ask.” On Oct. 24,
according to Carnegie-Mellon graduate students Brian Reid
and Mark Gos, a well-known department store in the heart
of Pittsburgh advertised the appearance of a “domestic
robot.” “Knowing of CMU’s pioneering work, particularly
in the field of speech recognition, various friends called
CMU to ask how this robot might be so much better at
speech recognition than our talented and dedicated research
teams,” they wrote in a memorandum sent to colleagues at
Stanford, MIT, and elsewhere. “Rising to the challenge, four
courageous members of our department went downtown to
investigate. They found a frightening sight: in the men’s
department, among the three-piece suits, was a 5’ 2” image
of an aerosol can on wheels, talking animatedly to the
crowd.”
Upon closer investigation, the CMU experts saw that the
robot was surprisingly crude. “It didn’t seem able to tell that
an object was blocking its path. Covering the faceplate did not
change its behavior at all. Since the robot seemed able to
navigate around the room without hitting anything, we found
it quite curious that it had no detectable sensory reactions.
Feeling more dubious, we began to look around the room for
evidence of remote control. Lo and behold, about 10 feet
from the robot, standing in the crowd, we found a man in a
blue suit with his hand held contemplatively to his mouth.
After watching for a while we noticed that whenever the robot
was talking, the man in the blue suit could be seen muttering
into his hand.”
At a second store, “they found a furtive-looking and rather
disagreeable person loitering in the back of the room. He was
Page 4
carrying an airline flight bag with his hand stuck down in the
bag.” The investigators challenged the man, suspecting that he
was controlling the movements of Sam Strugglegear. The man
became “very excited and called for store officials to come get
us away from him,” the CMU scientists said. Quasar Industries
still maintains they will be ready to market a domestic robot
within 18 to 22 months. It will, they said, be able to perform
12 household tasks such as “serve your dinner, vacuum your
rugs, babysit for your kids, and insult your enemies.” Such
claims amuse, annoy, and sometimes downright anger artificial
intelligence experts.
Stanford graduate student Paul Martin, who is writing a
thesis on the problems of machines understanding natural
dialogue, believes much of the gullibility on behalf of the
public, the press, and department store managers stems from
recent technological innovations, such as hand-held calculators
and space missions. But there is a huge difference, Martin said,
between having a machine which can recognize separate,
simple words (this is possible now) and one that can under¬
stand the flow of language as spoken naturally. “Everyone in
the field would agree there are important scientific problems
waiting to be solved before we can get to the real thing. On
how long these problems will take to solve, you find a diver¬
sity of opinion. I tend to hedge by saying it will take between
five and 500 years. If you ask me to center it, I would say 40
years. The basic problems are how to make computers
recognize patterns in a noisy environment and how to go
about representing common sense knowledge about the world,
how to put that in a computer. In fact, what common sense
knowledge about the world is there? How can a machine be
taught to solve problems?
“One way these problems express themselves is in safety
issues. A household robot has to be very reliable, mechanically
and intellectually. It must distinguish between children and
animals as objects. It cannot think the baby is part of a stack
of pillows. It has to have a wide knowledge of different kinds
of objects to be intelligent.” In response to a reporter’s ques¬
tion whether the robot could tell a cup from a saucer, Reichelt
responded that it didn’t have to because it didn’t take them
off the tray. McCarthy then argued that, in that case, the
Quasar robot is too limited to be really useful. “Say it could
carry a dinner tray from the kitchen to the dining room,”
McCarthy said. “Someone in the kitchen would have to pre¬
pare the tray. The robot would be on a tread, according to the
company. But it still couldn’t be done safely. It could trip
on a rug. It could run over something. It could fall down the
stairs.”
Sam Strugglegear, also called KLATU in some news reports,
is not yet out of the news. A few weeks ago, while performing
at a shopping center in Philadelphia, the imitation robot
reportedly frightened a 10-month-old child. The child’s «
mother has filed suit for $100,000 in damages, saying that the
robot “accosted, touched, assaulted, and terrorized” her child.
The CMU scientists were reminded by these recent events
of another famous “intelligent” robot build by Baron
Wolfgang van Kempeler in 1769. This robot, known as “the
Turk,” would trounce people at chess, all while rolling its eyes
and nodding its head. Thousands of people, including Edgar
Allen Poe and Napoleon, examined it thoroughly and could
not figure out how it worked. It wasn’t until more than 70
years later that the truth was discovered. The robot cleverly
concealed a dwarf who was a talented chess player. Kempeler’s
description of his own robot, circa 1771, the CMU investigat¬
ors said, is probably the best summary of Sam Strugglegear:
“A mere bagatelle, not without merit in point of mechanism,
but whose effects appear marvelous only from the boldness
of conception and the clever choice of methods adopted for
promoting the illusion.”
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
60
Decoding Efficiency & Speed;
Pros & Cons of Table Look-Up
BYH.T. GORDON
College of Agricultural Sciences
University of California
Berkeley, CA 94720
Dear Jim, Received: 78 Jan 15
While some of your readers may have become as weary as
lam with my repeated attacks on the 650X legality-bytecount
problem, this is in a way a programming guinea-pig for
working-out optimization principles, relevant to all problems.
Even your non-650X readers may find something of value in
the enclosed MS, as it touches on some universal problems: the
chioce between decoding-logic or table-look-up programs, the
extent to which subroutines should be designed to be non¬
destructive and purely-informative, and the uses of antibug¬
ging code. My ultimate goal is to develop scanning-debugging
to a higher level. For this, the basic components of the
debugger must be fast, efficient, and above al bug- free.
Sincerely,
H. T. Gordon
The question of how to optimize a decoding subroutine,
previously touched on in my notes in issues #17 and #19
of DDJ (1977) using decoding of the number of bytes
required by 650X opcodes as an example, is re-opened by 2
new solutions: CNTBYT (written by Jim Butterfield and
reproduced here with his permission) and BYTCNT (my
own response to his challenge). Both optimize coding
efficiency, and it is unlikely that a solution in fewer than
28 bytes exists. Both sort the 151 legal opcodes into the
same 6 groups as my earlier subroutine BYTNUM. However,
CNTBYT classes illegals of type X 0 B as 3 byte codes while
the others class them as 2 byte codes (which is how the
650X control unit executes them, but this is immaterial
since all routines class illegals of type X2 as 2 byte codes
although most of them are not executable).
The important differences are in structure and timing.
CNTBYT uses an elegant and highly instructive linear sequence
of bit-manipluations that cause each of 5 classes of opcodes
in turn to become zero and exit, while the 6th class exits as
non-zero. BYTCNT emulates BYTNUM by first sorting into
subclasses X(0-7) and X(8-F) by a BIT test of bit 3, then
shifts to destructive logic in each branch to attain higher
code efficiency. Unlike BYTNUM, both new routines destroy
the accumulator.
All routines have different path lengths (measured in
clock cycles from entry to exit, including the 6 cycles for the
main program JSR and 6 cycles for the RTS) for each of the
6 opcode classes. An index of relative speed (not weighted
for difference in opcode usage frequency) is easily calculated
by dividing 2 (N X T) by £ N, where N is the number of
legal opcodes in a class and T the path length in cycles for
that class. BYTNUM has the fastest index, 30.6 cycles (range
28 to 37). BYTCNT is slower, 32.5 cycles (range 29 to 39).
CNTBYT is slower still, 39.3 cycles (range 23 to 42). The
delay is caused by its having to sort out 3 small classes (con¬
taining only 11 of the 151 opcodes) before it can work on the
3 large ones. The lesson to be drawn from this is that linear-
sequence logic is not inherently slower (as I implied in my
previous DDJ notes) and might even be faster if its first
stages could sift out the majority of the items being sorted.
However, the range of sorting times is necessarily wider.
One additional point: to make the 2 new routines fully equiva¬
lent to BYTNUM, one would have' to add a PHA to store and
a PLA to restore the accumulator, at the cost of 2 more bytes
and 7 more cycles. However, the main program might be
able to restore the accumulator more efficiently.
One interesting point about all these “decoding” routines
is that, although their branch instructions subdivide opcodes
into 6 classes, they return with 3 byte-count classes
re-encoded (as 01, 02, and 03) in the X register, so that a
little more decoding logic is required to use this information.
A second point, that 1 have emphasized before but that
deserves reiteration, is that they all produce additional
information as an incidental effect. E.g., CNTBYT and
BYTCNT cause only 1 byte opcodes to set the Z flag, i.e.,
this type is truly decoded. It would be easy to recode
BYTNUM to have the same effect, by omitting its inner RTS
and relocating its TRICK sequence outside the subroutine.
This would save 1 byte and very slightly reduce its speed.
CNTBYT returns with the carry flag always equal to bit 7
of the opcode, and the sign flag always cleared. BYTCNT
sets the carry flag equal to bit 4 for all 1 byte opcodes; it
clears the carry for opcodes of type (0,1) (0,7) and sets it
for all others. The BIT instruction in BYTCNT and BYTNUM
sets the V flag equal to bit 6 for all opcodes; in BYTNUM it
also causes all 1 -byte opcodes to return with the N flag equal
to bit 7.
I still prefer and recommend BYTNUM, although in my
KIM system it takes 32 bytes (that would be 31 in the minor
revision suggested above). In a well designed system, every
one of the 256 possible bit patterns would be present in
ROM (for use as numerical constants, BIT masks, etc.) and
BYTNUM could be coded in 30 (or 29) bytes, a small price
to pay for non-destructive logic and higher speed.
Unfortunately (as I showed in a recent note in Kim User Notes)
the KIM-ROM omits 81 of the possible patterns, including
39 of the 151 legal opcodes.
In the letter in which Jim Butterfield sent me his CNTBYT
program, he also pointed out that a table-look-up operation
would optimize timing. One way to do this is to move the
opcode into an index register to get the content of a unique
location in a 256 byte table. A content of 00 would identify
an illegal (setting the Z flag), while contents of 01, 02, or 03
would give the byte-count of a legal. A 7 byte program insert
(XINFOA, cf. listing) would do the work of both BYTNUM
and OPLEGL at a cost of (7+M) main program bytes and
(10+N) cycles. The values of M and N depend on whether the
opcode needs to be restored in the accumulator (if not, both
are zero) and on the kind of coding the main program is using
to pick up a sequence of opcode bytes (most likely the LDA
(INDIRECT), Y instruction with M = 2 and N = 5). Since
the existing (not optimized) decoding logic version of
OPLEGL needs 66 subroutine bytes and has a speed index of
37 cycles (range 24 to 63), the XINFOA insert would run
more than 4 times faster than the OPLEGL + BYTNUM
combination. To anyone enamored of speed (as I am) this
is very attractive. An added superiority is that the main
program can decide what to do with an illegal. If a program
BREAK is desired, the branch offset ILLEG can be directed
to the nearest 00 operand, otherwise to an illegality handling
routine. One of several flaws in OPLEGL is that it forces a
Number 22
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
61
BREAK for illegals. A well designed subroutine should return
information and not make decisions.
Nothing comes free, and the price of the XINFOA speed
is a very long table, with every opcode a unique class,
vulnerable to bugs if located in RAM. Ideally an info table
like TAB256 should be in ROM, but it uses only the 2 low-
order bits and one hesitates to waste 75% of the bits in an
expensive ROM. The solution would be to encode other
information in the high-order bits, and AND them out to
retrieve the legality/bytecount data. The dilemma is: what
other information?
I briefly explored another approach, fully packing the
infobit pairs of TAB256 into a 64 byte table. Retrieval needs
a 36 byte program, too long for a main progarm insert, and
with a speed index of 63 cycles when made into a subroutine.
This is not good enough to be worth presenting here.
A more promising use of info tabling is my new legality-
testing subroutine, HYLEGL, that has many advantages
when compared with OPLEGL. It needs only 64 bytes, saves
and restores the accumulator, and returns with the carry
flag set by illegals and cleared by legals. Its speed index is
44 cycles (range 36 to 71). A revision of OPLEGL to make
it fully equal to HYLEGL would be about 10 bytes longer
and 2 cycles slower.
HYLEGL is a “hybrid” operation that retains the decoding
logic of OPLEGL for the 128 “odd-number” opcodes because
this is both fast and efficient. For the 128 “evens” it encodes
legality as single infobits packed in a 16 byte table, INFTAB, a
1 bit meaning illegal and a 0 bit legal. A table-addressing index
from 0 to F is generated by ANDing bits 4321 of the opcode,
bit 0 (always 0 for evens) having been right-shifted out. The
16 infobytes correspond to the original opcode sequence:
X 0 0, X 0 2,. .. .X 0 E, X,0. .. .X,E. Since 7 of the infobytes
contain no 1 bits, legality is proved by the setting of the Z
flag at the load into the accumulator, so no retrieval is needed.
For the remaining 9, the correct infobit is moved into the
carry flag by a sequence of from 1 to 8 ASLs, controlled by
analyzing the status of bits 765 of the original opcode (stored
in the temporary zero-page location COPY).
Since INFTAB contains 128 unique classes, it is as
vulnerable to bugs as any other table in RAM. Since it is short,
it is much easier to,check and also more likely to get itself
fitted into a ROM. Decoding logic in RAM is of course not
immune to bugs, but when a large class is involved the bug
will show up very quickly. In a unique class, rarely use-tested
(such as the illegals individually weeded out by OPLEGL)
a bit-error bug may lurk for a long time before inflicting
damage. Worse, the damage may be neither suspected nor
detected; the output will look right but be wrong, and may
even create a new hidden bug in other programs.
HYLEGL highlights some “gray areas” of subroutine
design, where programming philosophies differ. The X
register is used in its table look-up segment, but the pre-call
X content is saved and restored at a cost of 4 bytes and 6
cycles. Its operations destroy the pre-call content of the
accumulator, but this is saved and restored at a cost of 3 bytes
and 7 cycles. It can be argued that only the main program
really knows what needs to be saved and how and where to
save it and when to restore it. By omitting the saves, HYLEGL
would need only 57 bytes and 34 cycles, but greater pre¬
caution would be needed in the writing of the main program
(perhaps not an evil). Should subroutines try to leave no
traces of their work, other than the intended ones? Despite
its saves, HYLEGL does leave traces, in the zero-page
locations STORX and COPY and as incidental effects on the
N, Z, and V flags. However, the PLP and PHP instructions
of the 650X make status saving especially easy for the main
program, and low zero-page locations are commonly viewed
as temporary scratchpad area. My current view is that sub¬
routines should be written to save on-chip registers, since it
is easy for a user to remove any save instructions he does
not want.
In order to make the high speed of the XINFOA/TAB256
approach immediately available, I am adding to the package
subroutine MKTABL, that uses HYLEGL and BYTNUM to
construct a temporary TAB256 in a RAM page. MKTABL
is long (52 bytes) because it has an unusually high content of
antibugging code and also serves as a testing/debugging
program for the legality/bytecount subroutines. A large table
in RAM is not only insecure but hazardous to generate. The
data generating routines may be yielding some incorrect
values. The write operation may be overwriting a RAM page
other than the intended one, or trying to write in nonexistent
RAM (that in systems not fully address-decoded may prove
to be existent RAM with valuable stuff in it) or in write-
protected RAM or in ROM.
Before calling MKTABL, a main program is expected to
write into location BASEHI the number of the RAM page into
which the table will be written. MKTABL compares this to
the unique page number in its own coding; only if they are the
same will table writing be permitted. It also sets the low base
address for the table to 00, to ensure that the table will lie
within the bounds of the one RAM page. This is part of the
initial zeroing of 5 adjacent zero-page locations, that will
contain useful information when MKTABL exits. The lowest
one, COPY, is used by HYLEGL and will contain $FF at a
correct exit; each run of HYLEGL stores the opcode it has
worked on, unaltered except for the 72 “evens” that require
infobit retrieval (that causes one ASL of COPY).
The next higher location (LEGCNT) contains $97 at a
correct exit, since this counter is incremented before each
call to BYTNUM, of which there will be 151 if HYLEGL is
working properly. The next location (CHKLO) is a 1 byte
checksum that contains $41 at a correct exit. The next
location (TABGEN) indirectly counts the number of table-
writes, containing either 00 (if no table was written) or $FF.
This is a bit trickier than a simple count. After each write,
the current value of the opcode is moved from the Y index
into the accumulator, destroying the infobyte content so that
the subsequent reloading of the infobyte from the table
location is a test that the correct value was indeed stored
there. The actual content of TABGEN is the current opcode
value, from Y, that if all is well is also the count of writes.
Finally, the content of BASELO should always be 00,
and BASEHI should contain the number of the unique permis¬
sible RAM page if the main program commanded a table-
write, and some other number if not. A simple way to imple¬
ment a no-table command would be an LDY #$06 followed
by a JSR SETEX to bypass the first MKTABL instruction,
since SETEX would zero BASEHI.
The terminal instructions of MKTABL control the 2 flags
that will tell the main program what has happened. The BIT
sets the V flag if a table has been written (TABGEN = $FF),
and clears it if not. The crucial instructions compare the
checksum in CHKLO with the correct value $41, setting the
Z flag if all is well, clearing it if not. A great variety of errors,
either in MKTABL itself or in the subroutines it calls, can
cause a wrong checksum. Much information on the kind of
error can be derived from the content of the 6 zero-page
locations, of the accumulator (should be $41) and of the
X and Y registers (both should be 00). If a table was written,
very detailed information on operation will be found in the
infobyte sequence.
The antibugging logic in MKTABL, although far from a
total bugproofing, is clearly costly in memory and time.
Programs that aim to optimize timing, such as the XINFOA/
Page 6 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 22
62
TAB256 combination, can tolerate little or none. (An example
of very light antibugging would be addition of an AND #$03,
at a cost of 2 bytes and 2 cycles, to erase the 6 high-order
bits of the infobyte.) The major insurace against error for
such programs is a thorough testing by an antibug test
program, both before and after each use. In service programs
resident in RAM, like MKTABL, error-proofing can be given
priority. It may be desirable to trade off more memory to
attain higher speed, but one should never trade off reliability!
On this subject, the chapters on antibugging, testing, and
debugging in E. Yourdon’s Techniques of Program Structure
and Design (Prentice-Hall, 1975) make interesting reading.
To sum up, tables can indeed play useful roles beyond
their classic one of defining arbitrary relations and rules
(such as the metalogical ASCII decision that $41 represents
the letter A). These other roles have been obscured by the fact
that it is simpler to implement a de novo calculation of a math
function than a look-up in a gigantic table. With tables of
more modest size, table look-up can (as Jim Butterfield
suggested) maximize speed, at an acceptable (though relatively
high) memory cost. When decoding logic proves to be very
intricate (many small or unique classes) the use of tables may
also be more code-efficient. Furthermore, programs may be
easier to write because similar retrieval logic may be applicable
to a variety of tables. There is probably some trade-off point
(more that 35 bytes of decoding logic, more than 10 classes
decoded?) where the entabling of pre-decoded information
becomes an optimal solution of the dimensions of the table
can be kept within reasonable bounds (no more than 32
bytes?).
0230
2
i
8
A
B
D
F
021+1
3
5
7
9
A
024B
(coding Tor CNTBYT and BYTCNT)
A2 01
49 20
F0 13
29 9F
F0 11
0A
49 12
F0 0B
CNTBYT
29 1A
49 02
F0 06
29 10
D0 01
E8
THREE
E8
TWO
60
ONE
LDX #$01 (initialize X)
EOR #$20 (flip bit 5)
BEQ THREE (only $20)
AND #$9F (bits 5,6 out)
BEQ ONE (only (0,4,6)0)
ASL A (shift bit 7 out)
EOR #$12 (flip bits 3,0)*
BEQ TWO (only X Q 9)
AND #$1A (bits 4,1 out)*
EOR #$02 (flip bit 0)*
BEQ ONE (X(8,A)>
AND #$10 (all but flipped
bit 3 out)*
BNE TWO (resid. X(0-7))
INX (resid, X(9-F))
INX
RTS
* comment refers to original opcode bits
before left-shift at 023A
0230
A2
01
BYTCNT
LDX #$01
2
2C
36 02
BIT BYTCNT+6 (test bit
5
D0
08
BNE HALFOP (all X(8-F)!
7
C9
20
CMP #$20
9
F0
0E
BEQ THREE (only $20)
B
29
9F
AND #$9F (bits 5,6 oul
D
D0
0B
BNE TWO (all except
(0,4,6)0)
F
29
15
HALFOP
AND #$15 (retains only
bits 0,2,4)
0241
C9
01
CMP #$01
3
F0
05
BEQ TWO (X (9,B))
AND #$05 (bit 4 out)
5
29
05
7
F0
02
BEQ ONE (X(8,A) and
(0,4,6)0)
9
E8
THREE
INX (resid. X(9-F))
A
E8
TWO
INX
024B
60
ONE
RTS
X1NF0A TAX
LDA TAB256, X
BEQ ILLEG
TAX
026E
48
HYLEGL PHA
(save opcode in stack)
F
%
10
STA
COPY (store work-copy)
0271
4a
LSR
A (bit 0 to carry)
2
90
0A
BCC
TABLOP (do evens/table)
k
4A
LSR
A (bit 1 to carry)
5
B0
05
BCS
ILLEX (all X(3,7,B,F))
7
C9
22
CMP #$22 (LSRed $89)
9
F0
01
BEQ
ILLEX ($89 illegal)
B
18
CLC
(legals clear carry)
C
68
ILLEX PLA
(restore opcode in A)
D
60
RTS
E
86
0F TABLOP STX
STORX (save X register)
0280
29
0F
AND #$0F (bits 7,6,5 out)
2
AA
TAX
(4321 to X index)
3
BD
9E 02
LDA
INFTAB,X (load infobyte)
6
F0
12
BEQ
EXIT (all 0 bits, legal)
8
06
10
ASL
COPY (bit 7 to carry)
A
B0
04
BCS
STEPA (bit 7=1)
C
0A
ASL
A (leftshift infobyte)
D
0A
ASL
A
E
0A
ASL
A
F
0A
ASL
A
0290
24
10 STEPA BIT
COPY (bits 6,5 to N,V)
2
30
02
BMI
STEPB (bit 6=1)
4
0A
ASL
A
5
0A
ASL
A
6
70
01 STEPB BVS
STEPC (bit 5=1)
8
0A
ASL
A
9
0A
STEPC ASL
A (infobit to carry)
A
A6
0F
EXIT LDX
STORX (restore X)
C
68
PLA
(restore opcode)
029D
60
RTS
INFTAB table for even opcodes
029E 10 DF 0D 00 00 00 01 00
02A6 00 FF CF 00 00 OF DF 10
(coding for MKTABL)
02AF
02B1
3
8
9
A
D
F
02C1
3
6
7
9
B
D
F
02D0
2
k
5
7
9
A
C
E
02E0
02E2
A0 05
A2 00
96 0F
88
D0 FB
D8
98
20 6E 02
A2 00
B0 05
E6 11
20 10 02
8a
A2 XX
e4 15
D0 07
91 14
98
ii
65
B1
18
65 12
85 12
c8
D0 DD
24 13
A9 41
c5 12
60
MKTABL LDY #$05 (zero 5 loci)
SETEX LDX #$00 (notable entry)
ZEROIT STX COPY-1, Y
DEY
BNE ZEROIT
CLD (clear decimal mode)
OPBYTE TYA (opcode from Y to A)
JSR HYLEGL (test legality)
LDX #$00 (rezeroes X)
BCS MOVXA (illegal bypass)
INC LEGCNT (count legals)
JSR BYTNUM (bytecount to X)
MOVXA TXA (bytecount from X to A)
LDX #$XX (RAM table page #)
CPX BASEHI (compare page #
set by program)
BNE NOTABL (nowrite if #)
STA (BASELO),Y (write)
TYA (opcode from Y to A)
STA TABGEN (count writes)
LDA (BASELO),Y (read table)
NOTABL CLC (clear carry for add)
ADC CHKLO (bytecount sum)
STA CHKLO (store checksum)
INY (next opcode )
BNE OPBYTE
EXIT BIT TABGEN (sets V if table)
LDA #$41 (valid checksum)
CMP CHKLO (compare actual)
RTS
I
Number 22
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 7
63
BASIC SEARCHER/PATCHER
Dear Dr. Dobb’s: Received: 77 Dec 9
The enclosed program should be of use to anyone seeking
to modify MITS 4.0 or 4.1 BASIC. It should be used with
an 8080 disassembler such as the one published in the March
1977 issue of Dr. Dobb’s Journal.
The program has two functions; viz., searching and
patching. The code to be searched or patched may reside
anywhere in memory or on the reserved areas of the disk.
These areas comprise the first five tracks and are occupied
by the bootstrap/loader (sectors # 0,2,4,6) and by BASIC
itself (remaining 156 sectors).
The search function accepts any non-empty string of
characters or hexadecimal digits. A search is then performed
over the specified address range. Wherever a matching string
is found, the hex address is displayed or printed and the
search continued.
Two searching examples are given. In the first, the memory
resident BASIC code is searched for all occurrences of the
hex string ‘DB08’ (read disk status command). These indicate
where the disk I/O routines are located. In the second
example, a search is made through part of the BASIC code
on the disk for the string “RANDOM”. This was found only
once in the specified address range.
The patch function accepts a starting address, which is then
displayed together with the hexadecimal, decimal, and ASCII
equivalents of its contents. If the byte is to be changed then
a single character or two hex digits are entered. Otherwise
only a carriage return is entered. The patching address is
then incremented, decremented, or left unchanged, as selected.
Two patching examples are shown. In the first, the string
“RANDOM” beginning at address ‘069D’ is changed to
“RANCID”. In the second, the command ‘DB08’ (IN 08)
at ‘2E86’ is changed to D309’ (OUT 09). Since these changes
were made only to memory, they are not permanent.
James Monagan 806 Clark St.
Iowa City, IA 52440
10 PRINT"'PATCHER" 12/05/77
20 PRINT"PATCHES ANV BYTE IN MEMORY OR ON THE DISK COPIES OF MITS 4 0 B
ASIC AND BASIC BOOTSTRAP/LOADER "
20 PRINT"ALSO SEARCHES THROUGH ANY OF THE ABOVE TO LOCATE A GIVEN ASCII
OR BINARY STRING "
40 CLEAR500
50 TRK=-1
60 '
70 PRINT . INPUT"1> SEARCH 2> PATCH"; FC: IFFCC1ORFO2THEN70
80 PRINT:MEM=1 INPUT"1> MEMORY 2) BOOTSTRAP 3> BASIC"•MEM IFMEMCIORM
EM>3THEN80
90 IFFC=2THEN 980
100
110 SEARCH ROUTINES
120 PRINT:INPUT"DO YOU WANT HARD COPV";ZZ* PRINT
130 IF LEFT*<ZZ*. 1>-"V" THEN HDCPY=1ELSEHDCPV=0
140
150 GOSUB400 ' GET START ADDRESS
160 PC=X
170 PROMT*-"END"GOSUB420 GET END ADDRESS
180 HLTADR-X
190 GOSUB490 CHECK IT
200
210 PRINT 1-3:INPUT"±> CHARACTER- 2> HEX-STRING SEARCH 3> EXIT"; I IFI
=3THEN70
220 LINE INPUT"SEARCH STRING * "; SRCH* IFHDCPYTHENGOSUB65520
230 PRINT PRINT"SEARCH STRING = ", IFI—2THENPRINT"HEX ";
240 PRINT" •'"SRCH*" "
250 PRINT"ADDRESS"
260 IFI-2THENGOSUB870 CONVERT STRING IF HEX
270 SLG»LEN<SRCH*>:IFSLG-0THEN G0SUB65525 GOTO210 INVALID STRING' 1
280 BCX-1:SS-ASC <SRCH* > ' 1ST BYTE 1ST
290
300 SEARCH FOR STRING
310 IFMEM=1THENX-PEEK(PC)ELSEGOSUB690 ' FETCH NEXT BYTE
320 PC-PC+1 IFXOSSTHEN350 MATCH ?
330 IFBCXCSLGTHEN BCX-BCX+1:SS»ASC<MID*<SRCH*>BCJO > GOTO360 C OMPARE F
OLLOWING BYTE- IF ANV
240 X=PC-SLG.GOSUB610:PRINT ' FOUND, PRINT ADDRESS
350 IFBCX>1THENPC«PC-BCX+1 BCX-1 SS=ASC<SRCH*>
360 IFPCCHLTADRTHEN310
370 G0SUB65525
380 PRINT"HALT ADDRESS REACHED’" GOTO70
390
400 GET HEX ADDRESS
410 PROMT*-"START"
420 SRCH*="" PPINTPROMPT*• INPUT" ADDRESS <HEX> = ",SRCH*
430 IFLEN< SRCH* )O4THEN420
440 GOSUB870 CONVERT TO BINARY
450 I FLEN <. SRCH* > O2THEN420
460 X=256*ASC<SRCH*>+ASC<MID*-!SRCH*, 2>>
470 RETURN
480
490 CHECK HALT ADDRESS
500 IF MEM-iAND HLTADR/65526• THEN HLTADR=65526’
510 IF MEM-2 AND HLTADR>512 THEN HLTADR-512
520 IF MEM-2 AND HLTADR>22552 THEN HLTADR-22552
530 RETURN
540
550 FETCH THE NEXT BYTE
560 IFMEM-1THENX-PEEK v PC .* ELSEG0SUB690
570 RETURN
580
590 PRINT X AS A 2-DIGIT HEX NUMBER
600 PRINT RIGHT*'"00"+HE/» 2>; RETURN
610 PRINT X AS A 4-DIGIT HEX NUMBER
620 PRINTRIGHT*<"0000"+HEX*<X>, 4>> RETURN
620 '
640 PRINT HEX, DECIMAL, & ASCII STRINGS
650 PRINTTAB* 10 > GOSUB590 PRINT" " ; RI GHT * < " 0O0 "♦•MI D* ■' STP* < X >, 2 >, 3>> "
660 IFX>32ANDXC91THENPRINTCHR*<X>;
670 RETURN
680
690 FETCH BYTE FROM DISK BUFFER
700 IFMEM-2THEN XPC-PCELSE XPC-PC+512 BOOTSTRAP S ON 1ST 4 SECTORS
71G ADR-4+ <XPCAND127> TK*INT<XPC/4096> SC=2*< <XPC/128>AND31> IFSO30THEN
SC-SC-31
720
730 GET TRACI IF NECESSARY
740 IFTRK: -0THEN770
750 TRK-0 SEC .*.'= 1
760 IF'INP<8>AND64> :: 0THENWAIT8, 2, 2 0UT9-2 GOTO760 GET TRACK #0
770 IFTRK-TKTHEN810
780 WAITS, 2, 2 IFTRK: TKTHEN0UT9, 2 TRK-TRK 1ELSE0UT9,1 TR1=TRK+1 MOVE H
EAD TOWARDS DESIRED TRACK
790 SECZ—1 GOT0770
800 GET SECTOR IF NECESSARY
810 IFSECX-SCTHEN840ELSESEC ;.-SC ECNT-ld
820 SEC'*-DSK I * • SECX ' TST*=DSK I » • SEC*; • READ SECTOR
820 IFTST* :>SEC*THENECNT-ECNT 1 IFECNT: OTHENSSO ELSE G0SUB65525 PRINT"DI
SK RE AC- ERROR" STOP
840 X-ASC■MID*<SEC *.ADR > ;
850 RETURN
860
870 CONVERT HEX STRING TO BINARY STRING
880 J—1 S*-"" L-LEN<SRCH*>
890 FORI-ITOL
900 C*=MID*-SRCH*,I,1> IFC*«" "THEN950
910 IFC*>-"0"ANDC*<*“9"THEND-ASC<C*>-ASC<"0" .• G0T0940
920 IFC*>="A"ANDC*<="F"THEND—10+ASC<C* ASC - "A"> GOTO940
920 S*="" 1=1. GOTO950
94O J-CJ+1TAND1 IFJ=0THENT=DELSET-D+16*T S*=S*+CHR*-T>
950 NEXT
960 SRCH*—S* RETl IRN
970 •
988 PATCH ROUTINES
990 GOSUB400 PC-X GET ADDRESS
1000 PRINT PRINT"': OR X - ASCII XX = HE::. XXX = DECIMAL. RETURN = NO
CHANGE" PRINT
J010 IFMEM=2ANDPC>511 -OR - MEM-3ANDP023551 -THEN 380
1020 CHNG-0 ADR-0 G0SUB560 SX-X ' FETCH BYTE
1030 :=PC GOSUB610 PRINT" ", PRINT AC-DRESS
1040 X—SX G0SUB650 PRINT TAB925 ' PRINT OLC- VALUE
105O SRCH*-"" INPUTSRCH* L-LEN<SRCHi> PRINT NEW VALUE
1060 IFL-0THEN 1140 JUMP IF NO CHANGE
1O70 IFL-3ANDASC- SRCH*>=39THENSRCH*=MID*<SRCH*, 2, 1.- STRIP OFF QUOTES
108O IFL-3THENIFSRC H*>="000"ANDSRCH*<="255"THENSRCH*=CHR*(VAL<SRCH* > ■
CONVERT DECIMAL
109O IFL-2THENGOSUB870 CONVERT HEX
11O0 I FLEN-. SRCH* ^ OITHENFR1 NT CHR*-7-"l BYTE AT A TIME" GOTO1O30
1110 '
1120 MAKE PATCH
1130 SX=ASCvSRCH*> IFMEM-1THENPOKEPC. SXELSEMID*<SEC*, ADR, l.'=SPCH* CHNG-1
1140 FA=1 INPUT"PATCH 1> NEXT 2> THIS PREVIOUS BYTE 4> EXIT";FA
IFFA :iORFA>4THEN1140
1158 IFFA—2THEN1030
1160 IFFA-4THENGOSUB1220:GOTO70
1170 IFFA-1THENPC-PC+1.ADR-ADR+1ELSEPC-PC-1 ADR=ADR-1
1180 IFMEM=1THEN1010
1190 IFADR>—4ANDADR<—121THENGOSLIB840 SX=X GOTO103O
1200 GOSUB1220 GOT01010
1210
1220 OUTPUT SECTOR IF CHANGES MADE
1220 IFMEM-1ORCHNG-0THENRETURN
1240 CS=0 FORADR-4T0131 CS=<CS+ASC:<MID*<SEC*, ADR> > >AND255 NEXT
1250 MID*<SEC*, 133, 1>-CHR*'.'CS> UPDATE CHECKSUM
1260 ECNT-10
1270 DSKO* SEC*, SEC/i TST*=DSH*(SECX) WRITE SECTOR
1280 IFTST*<>SEC*THEf4ECNT=ECNT-l:IFECNT>0THEN1270 ELSE G0SUB6552S PRINT-
DISK WRITE ERROR" STOP
1290 RETURN
65509
65510 SUBSTITUTE CENTRONIC PRINTER'S PORT * FOR CRT'S
65520 IFTRMX-OANDINP< 33>-0THENTRMX-PEEK <4561> 0UT32,0.0UT34, 0 0UT33, 0 OU
T35,255 OUT32.44 OUTS4,44 P0KE4561, 32:P0KE4562, 246 P0KE4563,0 P0KE4564 1
94 P0KE4569, 35
65521 RETURN
65522
65523 RESTORE THE CRT AS OUTPUT PORT
65525 IFTRMX>0THENPOKE4561. TRMM P0KE4562, 230 P0KE4563, 2 P0KF4S64, 2©2 POK
E4569, TRMX+1 OUTTRMX.3 OUTTRMX,17:OUTTRMX, 1
65526 TRMX-0 RETURN
OK
Page 8 Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 22
64
FEBRUARY SHOW IN PHILLY
News Release Received:77 Dec 28
1978 Business and Personal Computer Sale & Exposition
Location: City Line Holiday Inn, Philadelphia, Pa.
Date: February 27th to March 1st, 1978
Hours: 10:00 A.M. to 8:00 P.M.
For further information contact: Produx 2000, Roosevelt
Blvd and Mascher St, Philadelphia, PA 19120 (215) 722-4837
GERMAN COMPUTER CLUB HOPES
Received: 77 Oct 10
“Call for interested individuals in (northern) Germany to
form a Hobbyist Computer Club. Please contact Ilja Burkoff,
Parkallee 105, D-28 Bremen. Tel: (0421) 34 71 79.”
I
V
PAD HEP
•hTCHES ANY BYTE IN MEMORY HR ON THE OISL COPIES OF HITS' 4 O BASIC AND
BAS l f BOOTSTRAP. ’LOADEF
AL 1 EARCHES THROUGH ANV OF THE ABOVE TO t.OCATE A GIVEN ASCII OR BINARY
STRING
1> SEARCH 2 • PATCH? 1
l; MEMORY • BOOTSTRAP 3> BASIC? 1
DO YOU WANT HARD COPY? N
START ADDRESS (HEX') * ° 0000
END Ml 'DRESS (HEX) = ? 5C00
L fHARAC TER- 2> HEX-STRING SEARCH 3) EXIT? 2
SEARCH STRING = DBAS
SEARCH STRING = HEX DB0S
ADDRESS
2E86
2E96
2EFD
2F08
3030
305?
3652
IB69
3B8F
"BC?
HALT ADDRESS REACHED'
I- SEARCH 2■ PATCH? 1
1 ■ MEMORY 2^ BOOTSTRAP 3 ■ BASIC? 3
DO YOU WANT HARD COPY' 1 N
START ADDRESS (HEX- = n OOOO
END ADDRESS (HEX> = ° 1O0O
1 • CHARACTER- 2) HEX-STRING SEARCH 3> EXIT? 1
SEARCH STRING = RANDOM
SEARCH STRING = RANDOM'
ADDRESS
069D
HALT ADDRESS REACHED'
If SEARCH 2> PATCH? 2
1) MEMORY 2> BOOTSTRAP 3) BASIC? 1
START ADDRESS (HEX) = ? 069D
X OR 'X' = ASCII, XX = HEX, XXX = DECIMAL, RETURN = NO CHANGE
069 D
52
082
R
?
PATCH
1>
NEXT
2>
THIS
3)
PREVIOUS
BYTE
4)
EXIT 0
069E
41
©65
A
?
PATCH
1 •
NEXT
2)
THIS
3)
PREVIOUS
BYTE
4)
EXIT?
*J69F
4E
078
N
?
PATCH
1)
NEXT
2)
THIS
3>
PREVIOUS
BYTE
4)
EXIT?
O6A0
44
068
D
? C
PATCH
1>
NEXT
2)
THIS
3)
PREVIOUS
BYTE
4)
EXIT?
06A1
4F
079
O
? I
PATCH
1)
NEXT
2>
THIS
3)
PREVIOUS
BYTE
4)
EXIT?
06A2
4D
077
M
? D
PATCH
1>
NEXT
2>
THIS
3)
PREVIOUS
BYTE
4>
EXIT?
1> SEARCH 2)
PATCH 0 2
1) MEMORY 2)
BOOTSTRAP
3)
BASIC? 1
START
ADDRESS
(HEX >
■ ?
2E86
X OR
X'
= ASCII,
XX =
HEX.
XXX = DECIMAL-
RETURN = N
2E86
DB
219
? D3
PATCH
1>
NEXT
2)
THIS
3)
PREVIOUS
BYTE
4>
EXIT?
2ES7
08
008
? 09
PATCH
1)
NEXT
2)
THIS
3)
PREVIOUS
BYTE
4)
EXIT?
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 9
65
A Simple Technique for Static Relocation of
Absolute Machine Code
BY GARY AKILDALL
Digital Research
Pacific Grove, CA 93950
One principal difficulty with newly evolving computer
technology is that software generation tools generally lag
corresponding hardware facilities, thus forcing the software
engineer to resort to outmoded techniques to produce soft¬
ware systems.
The purpose here is to present one area of difficulty—that
of a static program relocation—and to offer a simple solution
which can be applied to nearly any microcomputer software
environment where relocation is not supported by the manu¬
facturer.
The need for static relocation arises most often in a situa¬
tion where the software systems must be reconfigured in the
field. For example, data entry equipment manufacturers often
provide a range of optional peripherals which can be attached
to user’s equipment as processing requirements change. Each
peripheral usually requires a software “driver” which is device¬
specific, and interfaces the device to the operation environ¬
ment.
A common approach to software reconfiguration is to
arrange the individual translated peripheral drivers into distinct
machine code modules which can be selectively brought
together to form an integral system at the customer site.
In order to perform the field reconfiguration, each module is
translated so that it originates at location 0 in memory and,
when it is brought together with other modules, it is placed
at the next available memory location as the system is being
constructed. All machine code elements which are location
dependent must, of course, be altered to reflect the actual
locations that the driver occupies. Generally, the elements
which are affected are the addresses of branch destinations
and data addresses. If the locations of the affected addresses
in each module are known ahead of the system reconfigura¬
tion, the module can be placed anywhere in the final memory
image.
Simple Static Relocation
The process of constructing an executable memory image
from a set of relocatable modules, as described above, is
called static relocation. Unfortunately, very few microcom¬
puter manufacturers produce the address information with
their translator output which is required for the relocation
process. The method described below, however, can be applied
to the output of most manufacturers’ absolute translators to
derive the necessary relocation information. In order to be
specific, the Intel 8080 microcomputer is used in the
discussion with the understanding that the concepts can be
easily extended to differing architectures.
The Intel 8080 microcomputer has a 64K (65536 bytes)
memory space which can be thought of as 256 “pages” of 256
Page 10
66
bytes per page. Data and instructions are intermixed in this
memory space, and are addressed with a 16-bit address
operand which can be divided into an 8-bit (high-order) page
address (0-255), and an 8-bit (low-order) address within a
page. Typical 8080 instructions which can use these address
operands are shown in Figure 1, where PA denotes the page
address, and AWP denotes the address within a page. In
general, a machine code memory image consists of instruc¬
tions, instruction addresses, and data items. The instructions
and data items are independent of the actual location at
which the module finally resides. Further, only a subset of the
instruction addresses are dependent upon the module location.
That is, a load instruction may reference a buffer address
which is fixed outside the relocatable module, in which case it
does not change when the module is moved into position. If
the address references a branch location or data item within
the module, then the value of PA, AWP, or both, must be
biased by fixed values, dependent upon the final position of
the module in the resulting configuration.
MVI A,
PA
Move immediate to A
MVI C,
AWP
Move immediate to C
LXI D,
AWP
PA
Load DE with address
Jump to address
JMP
AWP
PA
Figure 1. Typical 8080 Instructions
A simpler form of relocation, called “page boundary
relocation,” is usually sufficient for field reconfiguration.
In this case, the module is relocated to a page boundary
so that only the page address (PA) need be changed to perform
the relocation, since the address within a page (AWP) remains
constant.
Page Boundary Relocation
In its simplest form, page boundary relocation can be
accomplished by constructing two parallel memory images
for each module. The first, called the “relative-0” image is
created by translating the module for execution at location 0.
The second, called the “relative-1” image is produced by
translating the module for execution at page 1 (address 256).
The relative-0 and relative-1 memory images can then be
compared to determine the high-order address elements which
must change when the module is moved to its final page
boundary location. Figures 2a and 2b show a simple program
segment assembled as relative-0 and relative-1 images. The
differences in the machine code images are circled, and are
thus the high-order addresses which must be biased when the
module is moved. Figure 2c shows the same program segment
assembled at page 5. Note that if the circled address fields in
the ralative-0 image are biased by an amount 5 (corresponding
to page boundary 5), they result in the proper values for the
relocated program.
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
0000
org
OOOh
.'relative 0 assembly;
| jnn|aaaa
|tt|dld2. . .dn|cc |
OOOO
3E00
start : mvi
a,d1
shr8 page address to a
0002
OEOA
mvi
c.dl and Offh .address in page
nn
— record length 01 - FF
0004
110A00
lx i
d,d1
;full address to d, e
aaaa
load address 0000-FFFF
0007
C30000
jmp
start
tt
— record type = 00
; data area
dl
— data byte 1
000A
dl: ds
2
;two unfilled
d2
— data byte 2
OOOC
00
db
0
;one filled element
000D
end
dn
— data byte nn
Relative-0
cc
— checksum byte
Hex
File:
JOA|OO0qoq3EOOOEOAllOAOOC3OOO0tC2
Figure 3. Hex File Format
dOlJOOOQ
PQOOF3
odooododoo
Figure 2a. Relative-0 Assembly
0100
org
100h
.•relative 1 assembly
0100
3E01
start:
mvi
a,d1 shr 8 page address to a
0102
OEOA
mvi
c,d1 and Offh;address in page
0104
110A01
ixi
d,d1
;full address to d,e
0107
C30001
jmp
start
data area
01OA
dl:
ds
2
;two unfilled
01OC
00
db
0
;one filled element
010D
end
Relative-1
Hex
File:
0A1010O00I3E010E0A110A01C30001JBE
ON
oiod
00I00F2
odooododoo
Figure 2b. Relative-1 Assembly
0500
org
500h
;assembly at page 5
0500
3E05
start:
mvi
a,d1 shr 8 page address t
0502
OEOA
mvi
c,d1 and Offh;address in p;
0504
110A05
Ixi
d.dl
;full address to d,e
0507
C30005
jmp
start
’
data area
dl:
ds
2
;two unfilled
050C
00
db
0
;one filled element
050D
end
An absolute loader reads each record of the hex file, and
loads the byte values at the load address specified by LA for
the next RL bytes, as shown in the algorithm of Figure 4. The
notation used in this algorithm is that of Knuth [Kn.], where
each step is labeled with a step name (Al. . . A16), followed
by a comment describing the action of the step. The action
itself is a series of assignments of expressions to variables, and
conditional control transfers. The algorithm begins at step Al,
and scans for the beginning colon for each record. When
found, the algorithm reads the record length and, if zero,
terminates the load operation. If the recrod length is not zero,
the load address is read followed by the record type (which
should be zero). The algorithm then loops between steps A6
and A12, reading successive bytes to memory while computing
the checksum. When the entire record has been loaded, the
final checksum byte is added, which should result in a zero
value. Upon completion of the algorithm of Figure 4, the
entire hex file has been read and loaded to an absolute loca¬
tion in memory.
The algorithm of Figure 5 is a simple extension of the pre¬
vious absolute loader, which reads two successive hex files.
The first hex file is the relative-0 machine code, produced by
translating the module for execution at location 0. The second
hex file is the relative-1 machine code, resulting from the
module translation when originated at location 256 (100 in
hexadecimal). The first part of the algorithm, given by steps
Al through A16 is similar to that of Figure 4, except that the
data is loaded to address LA+PG*256 which effectively
moves the module to the page boundary given by PG rather
than absolute address LA.
0A)0500)00I3E050E0A110A05C30005|AE
OTO5OCO0OOEE
dooloooobaoo
Figure 2c. Assembly at Page 5
The program which actually performs the relocation
process is a simple modification of an absolute loader. The
translator output for an 8080 microcomputer is a “hex
format” file, containing a sequence of absolute records which
give a load address and byte values to be stored starting at
the load address. The exact format of each record, shown in
Figure 3, begins with a colon (:) followed immediately by
a two digit record length (RL) and 4-digit load address (LA).
The 2-digit record type (RT) is always zero for absolute
records, and is followed by RL pairs of hexadecimal digits to
be placed at LA through LA+RL—1 in memory. The record
terminates with a pair of checksum digits: if the byte values
(hexadecimal digit pairs) are summed, starting immediately
after the colon, and, continuing through the end of the record,
including the checksum byte, then the sum should be zero
when computed with an 8-bit counter. The checksum byte
is included as an error detection mechanism. The last record
of a hex file is denoted by a record length of 00.
Note: nextchar reads the next ASCII character
nextbyte reads the next pair of digits
nextaddr reads the next pair of bytes
CS is the checksum accumulator (8-bits)
R L is the record length (8-bits)
LA is the load address (16-bits)
M[x] is memory location x (8-bits)
Al
[scan for :]
if nextchar 4 go to Al
A2
[set checksum]
CS : = 0
A3
[get length]
R L : = nextbyte
A4
[last record?]
if RL = 0 go to A16
A5
[set address]
LA : = nextaddr
A6
[set type]
RT : = nextbyte
A7
[load bytes]
if RL = 0 go to Al3
A8
[get byte]
b : = nextbyte
A9
[store byte]
M [LA] : = b
Al 0
[checksum]
CS : = CS + b
All
[next addr]
LA : = LA + 1
Al 2 [count length]
RL : = RL - 1,go to A7
A13 [checksum]
CS : = CS + nextbyte
A14 [total ok? ]
if CS = 0 go to Al
A15 [check error]
halt, "checksum error"
A16 [normal end]
halt, "tape read ok"
Figure 4. Absolute Loader Algorithm
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
67
Upon reaching step A16, the module has been loaded into
memory at page PG but is translated for execution at loca¬
tion 0 and thus would (most likely) execute improperly, since
the high order branch and data addresses must be biased by an
amount PG. Thus, steps R1 through R19 read the relative-1
hex file to determine the addresses which must change. These
steps are similar to A1 through A16, except the input data is
compared with memory for differences, rather than actually
placed in memory. In step R5, the load address is read as
before but, since the relative -1 machine code is biased by one
page, the effective address must be reduced by 256 bytes.
Step R9 compared the data loaded in the first phase with the
data read in the second phase: if the data is the same, then the
element is invariant in the relocation process. If the data dif¬
fers, then it must have been due to the difference in the
relative-0 and the relative-1 memory images. Further, this
difference must be exactly 1 since differences occur only in
the high-order address fields; otherwise an error occurs, and
the module cannot be relocated. When a relocatable element
is found, the original value loaded and relocated in phase 1
must be biased by an amount PG in step R11. Upon comple¬
tion of the second phase, the algorithm halts at step R19 with
the high order addresses altered by the proper amount in the
relocated module. Note that the algorithm given in Figure 5,
when applied to the relative-0 file of Figure 2a, followed by
the relative-1 file of Figure 2b, produces the relocated
machine code of Figure 2c, when page boundaiy PG=5 is
used.
Note: nextchar, nextbyte, nextaddr,
CS, RL, LA, and M are identical to
Figure 4. PG is the page number
where the relocated module will reside.
A1 [scan for:] if nextchar+ go to A1
A2 [set checksum]
CS
- 0
A3 [get length]
RL
= nextbyte
A4 [last record?]
if RL
= 0 go to A16
A5 [set address]
LA
= nextaddr
A6 [set type]
RT
= nextbyte
A7 [load bytes]
if RL
= 0 go to A13
A8 [get byte]
b
= nextbyte
A9 [store byte]
M [LA + PG * 256] :=b
A10 [checksum]
CS
= CS + b
All [nextaddr]
LA
= LA + 1
A12 [count length]
RL
= R L — 1, go to A7
A13 [checksum]
CS
= CS + nextbyte
A14 [total ok? ]
if CS
= 0 go to A1
A15 [check error]
halt,
'checksum error"
A16 [end rel -0]
go to Rl
Rl [scan for :]
if nextchar + ":" go to R1
R2 [set checksum]
CS
= 0
R3 [get length]
RL
= nextbyte
R4 [last record?]
if RL
= 0 go to R19
R5 [set address]
LA
= nextaddr + 256 x (PG
R6 [set type]
RT
= nextbyte
R7 [record done?]
if RL
= 0 go to R15
R8 [compare data]
b
= nextbyte
R9 [data same?]
if b =
M [LA] goto R12
RIO [page diff 1?]
if b + M [LA] + 1 go to R18
R11 [relocate]
M [LA] : = M [LA] + PG
R12 [checksum]
CS
= CS + b
R13 [next address]
LA
= LA + 1
R14 [count length]
RL
= RL — 1, go to R7
R15 [checksum]
CS
= CS + nextbyte
R16 [total ok?]
if CS
= 0 go to Rl
R17 [check error]
halt,
'checksum error"
R18 [reloc error]
halt.
'relocation error"
R19 [end rel -1 ]
halt.
'relocation done"
Figure 5. Relocating Loader Algorithm
The algorithm of Figure 5 can be easily translated to an
appropriate assembly or high-level language program to
perform this relocation process.
The processing of Figure 5 can be used to produce a more
compact form of the relocatable module by building a “bit
vector” which tabulates the addresses which require relocation,
rather than actually performing the relocation process. That is,
in step R11 the address LA must be biased by an amount PG
for proper execution when the module originates at address
PG*256. Thus, on the first pass, the data can be read to
memory and, upon completion of the pass, a bit vector is
constructed which has one bit position for each address within
the module. Before starting step Rl, the entire bit vector is
zeroed to indicate that no addresses require relocation. As the
second phase processing proceeds, each relocation address
determined in step Rl 1 can be “marked” by setting the cor¬
responding position of the bit vector. Upon completion of the
algorithm, the bit vector contains zeroes in the positions cor¬
responding to addresses which are invariant over the relocation,
and ones in the positions which require biasing by an amount
PG. The entire relocatable module can then be saved for later
static relocation.
Given that the relative-0 memory image has been saved
along with the relocation bit vector, the page boundary
relocation can be simply accomplished by reading the memory
image to its relocated page address PG. The bit vector is then
read and processed: for each bit position which is set, the
value PG must be added to the corresponding element which
was previously loaded. Note that this extension to the basic
algorithm of Figure 5 is included only for compact represen¬
tation, and produces exactly the same memory image as the
original algorithm.
A Case In Point
The following situation shows a case where page boundary
relocation is useful. The CP/M operating system [Ki] is a
simple small computer diskette based software system, which
implements a file management and program loading facility for
microcomputer development. The operating system is arranged
as a set of modules which are loaded into memory when the
computer system is started. User programs are then loaded
into memory from the diskette and, because of memory con¬
straints, must overlay non-essential portions of the CP/M sys¬
tem to reclaim storage for program and data areas. In order to
allow these areas of memory to be reclaimed, the CP/M system
is loaded into the high addresses of the memory space, and the
user programs are loaded into the low addresses. Thus, the user
programs can overlay the high addresses of memory when
necessary and, upon completion, cause the CP/M system to
be brought back from the diskette for the next operation.
Given that relocation is not supported by the manufacturer,
this memory organization presents a fundamental difficulty:
each CP/M operating system must be tied directly to the
memory size. If the user of CP/M owns a computer system
with 16K bytes of memory then a 16K version of CP/M must
be supplied. If the user adds memory to enhance system
capabilities, a different version of CP/M must be supplied to
support the larger memory space.
In order to overcome this difficulty, the CP/M system can
be reconfigured in the field to accomodate the increased mem¬
ory using the page boundary relocation technique described
above. In particular, each user receives a 16K version of CP/M
(the smallest amount of memory which is useful for CP/M
operation), along with a program which implements the recon¬
figuration. The user may optionally execute the program
which rebuilds the CP/M system, according to the existing
memory size, and places the relocated memory image back on
the diskette, ready for subsequent loading.
Page 12
68
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
FASTER DATA ENTRY FOR SC/MP
The CP/M debugger program, called the Dynamic
Debugging Tool (DDT), also resides in the upper portions of
memory so that it can co-exist with the programs under test.
Again, the area in which DDT is loaded depends upon the
current memory configuration, and thus page boundary
relocation is performed each time the DDT program is brought
into memory. The increased elapsed time for relocation of
DDT is negligible when compared to an absolute load, as long
as the bit vector technique of the previous section is used.
Restrictions
It should be noted that the technique described here is
by no means a complete linking loader: no address resolution
is provided between modules, and no load-time address
arithmetic is allowed. Sets of modules which co-exist in
an integral system must communicate through instruction
and data addresses. Using the technique presented here, the
communication must be performed through dedicated
absolute addresses for data items. Further, instruction addresses
must be established through a “root module” which contains
a jump vector with vector elements for each possible module
which could be configured in a final system.
Address arithmetic is often useful when combining modules.
In the simple page boundary relocation described above,
all address arithmetic must be performed at assembly or
compile time, and must consist only of simple operations
which involve a fixed positive or negative offset from a base
address, or a shift or logical and operation which extracts the
8-bit page address of a full 16-bit address. A relocation
error will occur, for example, if an 8-bit immediate operand
instruction is obtained from a 7-bit right shift rather than an
8-bit right shift of an address quantity.
In spite of these shortcomings, the technique has particular
advantages in being independent of a manufacturer’s capa¬
bilities, whims, and fancies. All language processors must
eventually produce an absolute memory image for execution
on the target machine, and thus the relocation process
presented here will continue to operate when new software
tools are introduced.
Acknowledgements
The author would like to point out that the techniques
presented here, although useful, are most likely not original
or particularly inventive. In fact, at least one individual,
Bruce VanNatta of IMS Associates, San Leandro, California,
has independently applied the methods to produce relocatable
PL/M programs. There are most certainly many other software
designers who have approached the relocation problem in a
similar fashion.
References
Kildall, G., Microcomputer Software Design: A Checkpoint.
Proceedings of the Fall Joint Computer Conference, 1975.
Knuth, D., The Art of Computer Programming. Volume I: Funda¬
mental Algorithms. Addison-Wesley, Reading, MA, 1975.
Dear Dr. Dobbs, Received: 78 Jan IB
Using the SC/MP kit (actually it is called Introkit this side
of the Big Lake) with the keyboard addition I often cursed the
program entry method as being somewhat slow. You have to
press MEM, TERM, then enter your data, and finally press
TERM again. That makes 5 keystrokes per byte where most
systems only use 3, i.e. two for the hex digits and one carriage
return. The enclosed program should solve this problem. All
should be self-explanatory except for a few details:
1. The initial data display is always 00, the following (after
first TERM) shows true data read from memory.
2. Assembler syntax is not standard but from a home¬
brewed ‘cross’ on an HP 9825A. The main difference is in
hex notation — I use xxH where National uses X’ or leading
zero.
3. The program is relocatable as only PC-relative jumps are
used (besides using SCMPKB which is assumed to start in
0000 ).
Best of all,
Erik Skovgaard
Nordlundsvej 10
DK-2650 Hvidovre
DENMARK
***** FSTKEY SCMPKB FAST DATA ENTRY ROUTINE *****
$$$$ Track 1 File # 6
1
2
3
4
5
e
7
8
ROUTINE FOP FAST ENTRY OF
PROGRAMS USING SCMPKB SYSTEM
JUST KEY IN BYTE AND PRESS TERM
ADDRESS IS THEN AUTO INCREMENTED
AFTER STOPINC THE BYTE.
ABOFT KEY RETURNS CONTROL TO SCMPKB
PROCRAM ENTRY ADDR IS CIVEN IN LOC
CF15 (UPPER) AND 0F16 (LOWER)
9
10
0F30
C4 OF
LDI 0FH
;P2=0F00
11
OF 32
36
XPAH P2
12
OF 33
C400
LDI 0
13
OF 35
32
XPAL P2
14
OF 36
C21 5
LD 15H (2)
;GET ADDRESS
15
OF 38
CA0E
ST 0EH (2)
16
OF 3A
C216
LD 16H(2)
17
0F3C
CA0C
ST 0CH(2)
IP
OF 3E
C400
LDI 0
;CLEAR DATA
19
0F4 0
CA0D
SI CDH(2)
20
0F42
900B
JMP "GODIS"
21
OF 44
C20D
NUM:
LD 0DH(2)
22
0F4 6
IE
RR
;SHIFT DIGIT
23
0F47
IE
RR
24
OF 48
IE
RR
25
0F4 9
IE
RR
26
0F4A
D4F0
AN I F OH
;AND APPEND
27
OF 4C
58
ORE
;NEW DIGIT
28
0F4D
CA0D
ST 0DH (2)
;SAVE RESULT
29
0F4F
C401
GODIS:
LDI 1
30
OF 51
37
XPAH P3
;P3*D1SP ROUTINE
31
OF 52
C43F
LDI 3FH
32
0F54
33
XPAL P3
33
0F55
3F
XPPC P 3
;DISPLAY
34
0F56
9 00 2
JMP "CMD"
;COMMAND RETURN
35
0F58
9 0EA
JMP "NUM"
; NUMBER RETURN
36
37
;COMMAND
PROCESSING
38
;ANY CMD
EXCEPT ABT IS OK.
39
40
OF 5A
C20E
CMD:
LD 0EH(2)
;P3«NEW ADDR
41
0F5C
37
XPAH P3
42
OF 5D
C20C
LD 0CH(2)
43
0F5F
33
XPAL P3
44
0F60
C2CD
LD 0DH(2)
45
0F62
CF01
ST @1(3)
;STORE BYTE, INCR
46
0F6 4
C30 0
LD 0(3)
;READ NEXT BYTE
47
0F66
CA0D
ST 0DH (2)
48
0F68
37
XPAH P 3
;STORE NEW ADDR
49
0F69
CA0E
ST 0EH(2)
50
0 F6B
33
XPAL P3
51
0F6C
CA0C
ST 0CH(2)
52
0F6E
90DF
JMP "GODIS"
;DISP NEW VALUES
NUM - 0F44
GODIS = 0F4F
CMD = 0F5A
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
69
Relocation Is Not Just Moving Programs
BY RICHARD L. ROTH
5 North Salem Rd.
Ridgefield, CA 06877
(203)438-3954
© RLR 1977
Once you start writing assembly language programs you will
find every program requires certain functions. Some functions
are so common, such as getting a character from the console
terminal, that you can build them into a system monitor. This
monitor can be put in PROM or loaded when you turn your
machine on. But the large majority of common functions are
only used for a class of programs. It’s wasteful to always have
them around so you only have them in memory when you
need them. During the stage of small programs and hand
assembling, each time you want any of the common functions
you must move it to the appropriate place and you must
‘relocate’ all absolute addresses, usually jumps and data. But
as programs get bigger and as the number and kind of common
modules grow, it behooves one to let the'computer do the busy
work of moving those modules. At the low level, if you separ¬
ate your code from data, you might find a relocator that can
move absolute code-fine for a 10 or 256 byte program. Not
so fine for 4000 bytes, esp., since you must watch carefully to
see if all the constants that look like addresses are not
changed. The next step up is to have an assembler do the dirty
work and start each program with a common set of routines,
in source. At around 6-8K of program code, even this becomes
unmanageable since just handling a source file that is 60K or
1000K can take 15 minutes just to read it off a floppy disk.
Keeping track of a program becomes harder and harder as it
gets bigger, a 2K program can have a 30 page listing if it’s
well commented. The final answer is to produce an intermed¬
iate phase where the computer has converted all the code to
internal form, i.e., the machine instructions are directly in hex
or octal, but is still keeping track of jumps and other location
dependent information.
Relocation Schemes
There are two general categories of relocation information:
dynamic and static. Dynamic relocation refers to information
still present at run-time which allows code to be moved. The
relative jump that the Z-80, 6800 and 6502, as well as most
large computers have is a good example. It runs the same no
matter where it is in memory. Minicomputers like the PDP-11
and NOVA have enough relative-type instructions that proper¬
ly written code can almost be moved between instructions and
still run properly. Large computers use a base register which
points to the start of the program and do all addressing relative
to that. Unfortunately, most micro’s either are not this flexible
or require very careful, expensive coding to do so.
to keep the relocation information around until all the
modules can be put together to form a final program. But in
forming the final program, all addresses are resolved into ab¬
solute addresses.
A Little Linking With Your Loader?
The two things an advanced assembler/linker scheme must
do are: move the code to the proper memory position, (reloca¬
tion) and allow modules to call each other by name, (linking).
A primitive form of linking is done in most large absolute
Page 14
programs by providing branch vectors. By previous agreement,
a set of jumps are set-up directly after each other, each jump
going to some internal module start. So if a program knows
where the jump vector is, it can get to any specific routine. A
full linking loader actually keeps the symbolic name assigned
to the routine or data location, and matches it with the
module that references the name as an externally defined
symbol. Some machines (such as 6502 and 6800) have a
special section of memory treated differently, called page
zero or base page. A good linker should help the programmer
manage page zero, as usually it’s limited to 256 bytes or so,
but is very important.
The Process
The final process consists of two or three steps. Each
module is assembled into a ‘relocatable object’ module. Then
all the object modules are combined by the linker into a single
object module, which is still relocatable. Finally the loader
converts the relocatable module into an executable load
module. Very often the process is simplified by combining the
linking and loading, so one program takes all the separate relo¬
catable object modules and produces an executable load
module.
In addition to the general simplification in managing smal¬
ler modules and the ability to just keep object modules for
common functions, a whole new capability enters the picture.
Any program which generates a similar object module can be
accepted by the linker/loader. This means FORTRAN,
Assembler, even BASIC modules can be combined into one
program, providing the object form is correct. (NOTE-most
BASIC’s in use today do not fit this scheme because they do
not actually generate machine code. But if the BASIC inter¬
preter has a simplified loader built-in, it can use those other
modules.)
With Reference to a Relocatable Object Format
I have now reviewed a dozen or so relocatable formats, in
addition to implementing my own for a number of machines.
Of those specifically for microcomputers, there are two roads
of thought: binary and ASCII. The binary direction tends to
be one of storage optimization, to the extreme of a pure bit
stream. The ASCII direction relates to interchangeability and
manageability, as ASCII is generally easier to move and
manage than binary. This is partially due to the human read¬
ability. For 8080/Z-80 processors, the INTEL absolute hex
format is often the starting point for building a full format.
When I started writing my relocatable, linking assembler
in early 1977, I reviewed all the available formats and decided
on the ASCII direction because of manageability. As 1 devel¬
oped the scheme, I kept building with a key goal being human
interaction. My format can be directly read, once the basic
rules are learned.
My orientation is 8080 byte machines with disk level cap¬
ability. Common address is a 16-bit value. 8-bit values gener¬
ally occur as parameters that may be handled on the source
level by ‘Including’ a parameter file at assembly time. Module
linkage is handled by allowing externals between modules.
Again, 16-bit values are sufficient. It is occasionally desirable
to add or subtract an offset from an external or do arithmetic
with externals. However, most often these practices lead to
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
70
bad programs so 1 decided not to allow other than simple
references.
As I developed my capabilities, simple relocation was not
enough. I needed the capability to separate code and data
into separate segments, to ease writing PROM-able software.
Hence to the normal relocatable segment (ROG), I added a
RAM segment. At the same time, I added further capability
to handle FORTRAN-like common blocks.
With the assembler and linker as usable tools, I built up a
library of often used functions. The most useful is a module
that allows character I/O to be done with disk, console, print¬
er, reader, or punch. My selection of an ASCII format greatly
simplified this library development. As to building a library,
all that has to be done is to concatenate the appropriate
individual modules into one file.
RLR Relocatable Object Format Specification
Rev 1.0
Version 1.1 12/1/77
This is the specification of a relocatable object format for
micro-processors. It is copyright (RLR 1977), but released for
general use providing that acknowledgement is made to the
source and any modifications are specified and returned to the
source for comment.
RLR Standard Relocatable ASCII Format
a) The ‘Assembler’ or ‘Compiler’ produces an ‘Object’ module
of ASCII records.
b) If the module contains relocating and/or linking informa¬
tion, it is a ‘Relocatable object’ module.
c) The ‘Linking Loader’ produces an ASCII ‘Object’ module
or a binary ‘Load’ module.
d) An ‘Entry’ symbol is a symbol defined locally and known
to other programs (alias public or internal symbol).
e) An ‘External’ symbol is a symbol used locally, but defined
in another program.
0 A ‘Local’ symbol is only known within a program.
g) An ‘Object’ module consists strictly of ASCII characters;
parity may be supplied. Each record begins with a delimiter
and ends with a return and line feed. The delimiter is
*=’ (3DH), although data records of absolute data may
begin with the Intel delimiter ‘: ’ (3AH). Numeric informa¬
tion is presented as hexidecimal ASCII with optional encod¬
ing. Once the encoding is removed, hex digits (0.. 9, A.. F)
will remain. The encoding is used to specify relocatability
or externality.
h) A ‘Symbol’ is up to 6 printable characters, excluding ‘ * ’.
Symbols with a length of less than 6 are right filled with
‘ * ’. The system may recognize certain special symbols:
‘STACK’ — top of program stack
‘MEMORY’ — first location of free memory.
‘ ? ’ — Blank common (for FORTRAN)
i) All relocation is of 16-bit values, although optional formats
provide use of high or low byte only. Relocation is handled
by declaring program or data ‘Segments.’ A segment is an
independently locatable section of data or code. Three
standard segments are provided: ROG (for normal use or
code), RAM (for data) or COM (for common data blocks,
per FORTRAN). ROG and RAM segments are handled
similarly as independent sections. COM is mapped so that
all COM symbols in different modules refer to the same
block of memory. Each segment allows for 64K addressabil¬
ity, unless an optional format is specified.
j) ‘Mode encoded ASCII’ is used to indicate relocatability or
externality of data. All encoded data are 16-bit values,
most significant byte first. The first character is encoded
based on the meaning of the data, the remaining 3 charac¬
ters are hex ASCII. All encoded data is converted into
16-bit data by resolving the relocation or other meaning
and then output as 2 absolute data bytes. If appropriate
(i.e., 8080/Z-80 type processors) then data is output least
significant byte first. If an optional format is specified,
encoding may indicate only the high or low byte is to be
output. Normally, a direct mapping may be made from
2 bytes of input data, to 2 bytes of output data,
k) An ‘Object file’ is a file consisting of one or more object
modules.
Record Formats
character
0
1 . .2
3. .6
7. .8
9.. N — 2
N-1..N
Record length:
Normally contains number of data bytes in record. This
implies length*2 characters of data. Symbols records specify
length as number of symbols. Any record with length of zero
is recognized as end of module record, regardless of record
type.
Record type:
0 data record
1 symbol record or end of file record
2 name record
3 library mark
4 option record
5 data count record
6 fix-up record
Checksum:
The checksum is a total of all numeric data bytes in the
record. Symbols are not added nor is the encoding informa¬
tion. The checksum number is the negative of the 8-bit total
of all data bytes, discarding any carry. So that if all data
including the checksum are added, the overall total should be
zero. This is the standard Intel checksum.
meaning
record mark (‘: ’ or ‘ = ’)
record length (0 if eof record)
load address (may be mode encoded)
record type
data
checksum
Specific Record Types
Data Record (type 0)
0 ‘: * or ‘ = ’
1. . 2 record length (data bytes) if 0, eof record with
load address meaning starting adr.
3.. 6 load address, (MSBy first) can be mode encoded,
relocatable
7. . 8 ‘00’ (record type)
9. . (8+len*2) data, can be mode encoded. Mode encoded
data never folds over record boundary
(9+2*len).. (10+2*len) checksum
Symbol record (type 1)
0
1. . 2 number of symbols
3. . 8 ‘000001’load adr & record type
9. . (8+12*len) symbol entries (number specified)
(9+12*len).. (10+12*len) checksum
Each symbol entry is 12 characters:
0. . 5 name (6 characters, right filled with ‘ * ’)
6. . 9 value (LSBy first, absolute hex)
10. . 11 type (absolute hex)
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
71
Symbol type bit assignment:
(lsb)
0
mode (0-absolute, 1-relocatable)
1
defined (1—true)
2. . 3
scope (00B—local, IB—entry,
10B—external, 1 IB—common)
4
equivalance (defined via EQU in asm
program)
5.. 6
segment (00B—ROG, 0IB—COM,
1 IB, system)
7
(msb)
undefined
Value’s meaning depends on symbol scope. If external, then
the value is a serial number of the external. Serial numbers
start at zero (0). This will be referenced when a data item is
encloded as external. If common, then the value is the length
of the common block which the symbol defines. Otherwise,
local or entry, the value is the relative address of the symbol
within the appropriate segment.
Standard type bit settings: ([ ] indicates optional values)
absolute symbol: [entry scope] + [equate] + [defined]
relocatable symbol: [entry scope] + segment + relocatable
+ [equate] +defined
external symbol: external scope
common symbol: common scope + defined
Name Record (type 2)
0. .2 ‘=04’
3. . 6 size of ROG segment (MSBy first, absolute hex)
7.. 8 ‘02’ (record type)
9. . 14 module name (right filled with ‘ * ’)
15. .18 size of RAM segment
19. .22 size of COM segment
23. .24 checksum
Module name is used for identification and selective load
processing. If an unnamed module is selectively loaded or dup¬
licate names exist, the loader should indicate a state of
confusion.
Library Mark (type 3)
0 . .2 ‘= 01 ’
3.. 6 function
7.. 8 ‘03’ (record type)
9. . 10 checksum
The function indicates that all modules to follow in the
current file are either to be forced loaded or selectively loaded.
The loader starts loading a file in forced load mode. If
switched to selective load mode, only modules that fill
unresolved externals will be loaded. However, as the module
name is used to catalog modules to be loaded, no duplicate
module name must exist for any module that is considered
for selective loading. The same file can switch between forced
and selective load.
Image Record Examples
data:
=NNAA AA00 < DD* > CK < CR/LF >
N—number of data bytes
A—load address
D—data
symbol:
=NN000001 < SSSSSSWWTT*N > CK < CR/LF >
N-number of symbols
S-symbol name
V—symbol value
T-symbol type
name:
=04RRRR02NNNNNNSSSSCCCCCK
R—ROG size
N—name
S—RAM size
C—COM size
library mark:
=01000L03CK
L—1 = selective load on
0 = selective load off
there are only 2 possibilities:
=01000003FC -off
=01000103FB -on
Mode Encoded ASCII
Mode encoded ASCII is a schema for using the rest of the
information storage capacity of an ASCII character while stor¬
ing hexidecimal information. Normal hex coding uses ‘O’.. ‘9’,
‘A’. . ‘F’ to represent the 16 hex digits. By selecting other
character ranges of 16 characters, each range can be defined to
have a specific meaning. The underlying character, after the
encoding is removed, is the first digit of the value correspond¬
ing to the catagory the encoding specifics. The remaining char¬
acters of the value use the normal representation of hex data.
For simplicity and human readability, all mode encoded val¬
ues are 16-bit (2 bytes, 4 characters) with most significant
byte first. Also, no mode encoded data is to fold between two
data records. To get a full range of relocation counters the full
ASCII character set must be used. If only upper case charac¬
ters are used then ROG allows 64K and RAM allows 36K, but
no COM is allowed.
Encodings
Externals:
First character is next 3 characters are hex numbers
from 000H.. FFFH. This allows a meximum of 4096 externals
in any one module, but does not allow for arithmetic with
externals.
Relocatable values:
First character is encoding value plus most significant digit
of data value. Next 3 characters are low 3 hex digits of data
value.
relocation encoding value
ROG ‘G’ (47H)
RAM ‘W’ (57H)
COM ‘g’ (67H)
This table shows the first hex digit as encoded as each
relocation type:
Data
Abs. Hex
ROG
RAM
COM
0
'0' (30H)
'G' (47H)
•W' (57H)
'g' (67H)
1
•V (31H)
'H' (48HI
'X' (58H)
V (68H)
2
•2' (32H)
T (49H)
'Y' (59H)
V (69H)
3
'3' (33H)
•J’ (4AH)
'Z' (5AH)
'j' (6AH)
4
'4' (34H)
'K' (4BH)
' (' (5BH)
'k' (6BH)
5
'5' (35H)
'L' (4CH)
'V (5CH)
'1' (6CH)
6
•6' (36H)
'M' (4DH)
'] ' (5DH)
•m' (6UH)
7
'7' (37H)
'N' (4EH)
(5EH)
'n' (6EH)
8
'8' (38H)
'O' 4F H)
'-' (5FH)
'o' (6FH)
9
'9' (39H)
'P' (50H)
A '(60H)
'p'(70H)
A
'A' (41H)
'Q' (51 H)
'a' (61H)
'q' (71 H)
B
'B' (42H)
'RM52H)
'b' (62H)
V (72H)
C
•C' (43H)
'S' (53H)
'c' (63H)
's' (73H)
D
■D' (44H)
T’ (54H)
'd' (64H)
't* (74H)
E
'E' (45H)
'U' (55H)
'e' (65H)
V (75H)
F
'F' (46H)
'V' (56H)
T (66H)
V (76H)
Page 16
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
72
Common Relocation Resolution
ca) COM relocation is handled by a mapping process, where
each module’s COM segment is distributed over the actual
COM blocks for the whole program. This is distinctly dif¬
ferent from ROG or RAM segments where each byte
allocated gets a different memory location. In common
blocks, all block/segments with the same name get placed
in the same memory location.
cb) The only entry symbol related to a COM block, is the
COM symbol. Its value is the length of the COM block.
No other entry may exist for any COM block.
cc) Since COM is a relocation type, program references may
specify offsets into COM. Any symbols within COM are
local symbols and are mapped at load time, as is any
COM data.
cd) Blank common, if it exists, must be the last common
label in the symbol table. The predefined name ‘?*****’
is generated for blank common.
ce) The COM size specified in the name record is the highest
COM relocation value used in a program (including space
reservation by DS). The size of blank common, if any,
is determined by subtracting the cumulative size of all
labeled common from the size in the name record. In
other words, the size in the name record ‘hangs’ over the
end of labeled common by the length of blank common.
The actual value of the bcom symbol (*?*****’) is
ignored.
cf) Labeled common blocks must all be defined lengths and
must be the same size in all modules.
eg) Blank common may vary in size. The loader will allocate a
block corresponding to the largest blank common block
specified.
ch) Common module relative is mapped from one relative seg¬
ment, in a module, to appropriate memory addresses
based on order and size of common blocks. Each common
relative reference is given a COM value based on the offset
from the beginning of its common block and the total size
of all preceding common blocks. At load time the process
is reversed to yield an offset relative to the start of its
common block. This offset is then added to the actual
start of the block in memory. This way all references to
any common block, even in different modules, get mapped
into the same absolute memory address.
ci) To resolve a common reference: first determine which
common block it refers to then resolved value: = common
block absolute start + (reference-reloc. com blk start)
Example of COM mapping
module
symbol
length
COM rel absolute address
module 1:
COM1
10H
0
1000H. .100FH
COM2
20H
10H
1010H. .102FH
COM3
15H
30H
1030H. .1044H
(bcom)
20H
45H
105CH. .107BH
nsize
65H
(size
in name record)
module 2:
COM2
20H
0
1010H. .102FH
COM4
18H
20H
1045H. .105CH
bcom
12H
38H
105CH. . 106DH
nsize
4AH
MEMORY —» 107CH (next available location)
Notice both modules’ blank common are different sized.
After all modules are loaded the largest blank common size
is used. The next available byte is defined as ‘MEMORY’.
Note the way COM2 has different common relative addresses
in each module, yet both are mapped into the same absolute
address. Also note the gap between COM3 and blank common
where the loader allocated COM4.
Optional Formats
There are a number of features that might be nice in a
relocatable format but are not included here. Some are
necessary for machines other than the 8080 line, for which
this format was designed Others are a convenience to
programmers that lead toward bad programming practice
(specifically externals plus offsets). To allow for future
flexibility, it was decided to specify how such additions
would be added to this format and a way of telling the loader
to expect same, or screan foul. The ‘option select’ record is
used to indicate target machine and active options. For one
pass compilers and others, a general fix-up record is specified.
These are suggested options and are not final, please contact
the author with suggestions!
The major deficiency of this format is that all relocatable
and external data are assumed to be 16-bit values. The Z-80
has an indexed mode which can benefit from 8-bit externals
and machines like 6800 & 6502 require 8-bit values for
indexing and page zero addressing. As such, three schemes are
provided to handle these: using the fix-up record, using the
high 32K of each relocation range encoding and adding an
extra byte on 8-bit references. The most desirable is using
the high 32K because the consistency of the format is
maintained—each input byte translates to one output byte.
However only 128 8-bit externals and a split page zero relative
encoding result if more than 128 bytes relative are required.
If a flag character is used (such as the on a 16-bit external)
then no such problems occur, but the format becomes less
humanly readable because the flag byte gets totally thrown
away and not passed to the output. The fix-up scheme used
on large computers totally destroys the primary goal that the
relocatable format will be directly humanly readable, and one
might as well use binary.
Option select (type 4)
0 . .2 ‘= 01 ’
3. .6 bits specification of options selected
(lsb) 0—non 8080 machine (default is Z80
and 8080)
1— use of high encoding for 8-bit data
(max 128 byte page zero relative)
2— full high encoding (256 byte PO
relative)
3— fix-up record allowed
4— record count record allowed
5— flag scheme for 8-bit data allowed
7. .8 ‘04’ (record type)
9. .14 machine type (ASCII name, right filled with **’)
8080, Z80,6800,6502, 8085
if other use, standard name of machine
15. .16 checksum
Record count record (type 5)
0
1. .2
number of counters
3. .6
overall checksum of all record checksums
7. .8
‘05’ (record type)
9. .10
number of type 0 records (data)
11. .12
>5 >» j >1
(symbols+eof)
13. .14
2
(name)
15. .16
3
(library mark)
17. .18
4
(option select)
19. .20
5
(record count)
21. .22
6
(fix-up)
23. .24
checksum
Number 22 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 17
73
The record count record is allowed to add to the security of
the system. It allows checking that no previous record has
been lost because of errors. Each count is an 8-bit, carry
ignored checksum of all previous record checksums. No
attempt has been made at error recovery, just error detection.
One implicit feature of this format is that intuitive error cor¬
rect can be made, if necessary, by the human operator.
Fixup Records (type 6)
0
1. . 2 number of fixup items
3.. 8 ‘000006’ (address and record type)
(9+len*5). . (10+len*5) fixup items:
< A AA A > < DDDD > < TT >
where: A—fixup address
D—data value
T—fixup type: 0= 16-bit value
1 = chain resolution
2=8-bit (hi byte)
3 = 8-bit (lo byte)
Both address (A) and data (D) are encoded ASCII (MSBy
first). The type indicates fixup required. A chain indicates the
target address is to be filled in with the data vluae, but first the
contents of that address are to be kept to point to the next
address in the chain. A value of zero indicates the end of the
chain. Otherwise, the data value is added to the current con¬
tents of the target location. This also allows arithmetic with
externals, as the data value may be an external. On 8-bit data,
the arithmetic is done with the 8-bit contents of the location
and the requested byte is substituted in.
Optional Encodings
The high 32K of encoding is reassigned to 8-bit values, on
the assumption that no modules that big will be generated.
This is largely valid, however, it is conceivable that a relocatable
object module produced by combining other smaller modules
could get that big.
Reassignments:
O (4FH). . V (56H) - page Zero relocatable (00H. . 7FH)
W (57H).. (5FH) - 1 byte externals (must be first in
serial sequence too)
o (6FH). . v(76H) - page Zero relocatable (80H. . 0FFH)
If 2 byte values describing 8-bit data items are to be
allowed, then the first character of the 4 character item is a
flag. The remaining 3 then contain the hex value desired.
Flags:
‘! ’ (21H) — page Zero relocatable
(22H) — 1 byte external (lo byte)
‘ # ’ (23H) — 1 byte external (hi byte)
‘$’ (24H) — 1 byte common segment reference
F- F-
*-«
> X
r x
J
C X
2- CL
X _J X
J O u
a 0* c
•- X O
x CL _J
0) > C UJ
z x cl 35
x x f- z>
■r- > (/•
x Z C
X X O
actii
o -• ui —«
a > a
ill O CO *-•
1 Z ill u
O - J)
-• O F- C
i.O Z -<
x - _j a
a x *-* uj
u a a
h ill C O
o x cl o
z o c z
O aJ
07 X
■ Q a aJ
x c a
F- X O G
~ X _J E
UJ uJ
E E
O O
O E
O c
X X
X X
o o
lL X
07 07
07 07
UJ UJ 07
X X J 07
a a c _j
a a z c
C C X z
UI X
a a - uj
c c X r-
OOaJx
_! _J UJ
O O O X
z z o
~ - X
r- r- UJ UJ
x x a j
< r c e a
i- »- 5 <r
01 0 ) Z h
x a
O X
o o
UI u
X UJ
X
X _J
UJ _j C '
x o x
UJ UJ UJ (
UJ UJ UJ C
-I
-I z
z o
07 O *->
z
x a c
UJ t
h- c c
X E O
o c <r
O X UJ
uJ CD
X O X
X o
C X X
G Z X .
_l uJ UJ «
uj i f- :
X H x
a
X z
O X
U D
X « - O
uj a a
H- - 07
x a: x 07
uj o o uJ
. o e a
x o <i a
c x x c
E II II li
II o UJ _J
c ui a i
<r o
e <r ►
X UJ >
O L
J > O O H (S
a a x
C Jhhh
H Cl J x X x
~ H ul UI UJ
UJ 0)
7 r- —
: O O
i <r x
. X X
: c
: i _i
j >
:• 07 o
j z x
x i-
E Z> 07
j x a
J X
: >
X <x
j Z E
F* F-
a a
c c
O O
r- X Eh
x £ c;
X “7 Z l
-I
C
OX
i <J J x
. - X c
: jo:r
a o
X X _J I
Z Z I O
a
_j >
I o
0 7 T.
> J c
O I F-
£ O) 07
ooo
o o o
o o o o
o o o o
O O D O
o o o o
bbboooooooooooboooabboooobooo
^ -v ^ o r. /-j r , n rt r\ n n
OOOoOOOOOOOO
o O O o o ooo O O OOGOOOOOC
OOOoOOOOOOOOOOOOOOO
O OOO OOOOOOOOOOOO
D o :> O O O O G O o o o o o o o
OOOOOOOOOoOOOOOOODOOw^vtwuuuuvi
.-7 o.-7 -in.^oooo OOOOOOOOOOOOOOOOOOO
Page 18
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
74
0014' i IGNORES ALL ERRORS UNLESS USER
z .
_i o o
I ~
> H
C Jj ii.
W0«
uj £
I >
rh
c c
z
• J Lit
1ZU
•- Cl
a o
0; r- o
Ul H
2 o
— X
o »-•
Ul
a
a
Z o.
a r
x 5
_i _j
a c
<r >-
h x
> X
Cu LU I
ui h-
CJ 2 ~
* «3
<r
' x
O 01
N
II o
A O
x »-
<i
i >
O X
o x
_j o
LU
X H
O D
a: z
v C
LU X
> O
c a
01
x x x
I lU LU
U I I
DlOhO
X x Ul
I UJ X
(J X C
i a a o i a <x i q
'>#
«■ cs $
O x _J + x «m
' a a a ' a x ' _j
OLUXCU.IOZ2CUJ
n x o x x o x v x
oi a:
x i _i _i
W o) _J _J
j 3 C C (J
x x o o i
-i
_J <T Cl
c x o
<SJ
a
a
a
a
(J
o
a
3
>
X Q
UJ
X
x a x a
O LU
— M
X z
-j
c
_j <r x o
c a x z x
5
a a q 3» x >
I «I c o z o
X X »-
> o O UJ
a
UJ
X u
- (J
X z
D IX
X (J O D X
a
oiao)ax>xa>>
D<rocooo<roo
X X
Ll
O 1
o
O _J (J “1 _J
o
u
a a a x *-4 x
r x x x
X
O 1
O 1
oi a o
£
o “i a oi a
i—
a
XOXOXXXDXX
X X X X
cc c
UJ -<
01 x
D UJ
X
•. a
~ M CO *0 O'
*0 >0 *0 *1 *0
o o o o o
o o o o o
8 s;
\ \ \ >
o a ll <
"*) »o r
o o o •:
o o o <
i o o o o in oo
. N f-» N N
>000000
>000000
oo a a *■* cj in
N N 00 00 CO
o o o o o o
o o o o o o
__ _ - - h 0> » Q U -« -« O'
iilUOUQ«UJOv<r CluJQU
\\\\\\\\\\ \\\\\\\\\\\\\\>
Nr^0'OOaJ«^^^C4in<0 0'<ra>OQUJULiL^C<01'
ccccccaiJJcaujjffljjuaaajaiaMajjcjL
OOO000000000000000000000C
OOOOOOOOOOOOOOOOOOOOOC
c V -O N
CJ O • J J o
o o o o o
o o o o o
Z UJ -
Ul > X
x _| _J X t- X
uJOL-Oul x Ul UJ
X - Ul 01 X a I
ociujocziaoacQ
-J 01 -J X _J
J>CUJJCNU)JO.>
COh-XCXZDCOO
OXOIQOO’jClUCLX
U 00
J X
§3
X X
(J
LU
E
x <X
O H
as
. *«
UJ 01
UJ CC UJ
38
5d
<r c
a X N
-J o cc
UJ O x
I - uJ
o c c z
J3CN
C O X Z
0X00
UJ 5
x 5
3> x
o z
X >-
X M
o z
a o
A X
V o
-J cc
C X
H UJ
o
r- Z
UJ
CJ
X _ .
x D K- O
uJ 01 x UJ
X iU UJ CC
O O <1 Z •-
a
i
J C C N h
c a x z ui
O _J O O D
X
- o
a ii ii
uj
a c c
o
O •* UJ
Z UJ D
UJ O _J
_i <r
JC>
C 3* ll
z
X Q O
x _| LU
U O »-
01 D
X UJ -J
OXO
UJ II 01
D O 01
JOUC
cjw-
3* UJ
X Z UJ
x UJ 01
uJ U X _J
X - K UJ
- ~ O ~
o
o
C ^ 00 x
ci a o in
U C* 01 o
C- Cl
sco oa
ciusn"
acsci
o oi a o
• o o a o
« - - - CJ
< o o o o
I o o o o
OOlc
CJ CJ CJ
o o o
o o o
sscaui
rj CJ CJ CJ CJ
O O O O O
o o o o o
CJ Cl
o o
o o
C) «r c- tf) -0
Cl Cl Cl Cl Cl
^^0;CfflaUuuy'JiO-r<r<r r ccNM) 1 )- 1 )CJJiOOOHrc<r<rNCa)aJiJjJ-
C1 Cl Cl Cl ^1 CO ?) M fo d M |V ' 0) «r «r t r c v v «r c r «r r «r r <r r r m D j3 l/l iO Jl if) if) u) u3 f) f> jl j3 >0
OOOOOOOOoOOOOOOOOOoOOOOOOOOOOOOOOOOOOOOOOOOOO
OOOOOOOOoOOOOOOOOOoOOOOOOOOOOOOOOOOOOOOOA^'-''-'^'
^ ' <0 <0 <0 -O <0 <0 *0
O O O O o o o
o o o o o o o
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 19
75
AD INFINITUM IN THE GREAT SOFTWARE
PIRACY DEBATE
D Q CJ
o ci a
a o u
•i U. cj
a go
J 01 o
i q o
I C Q
a co o
■- UJ 10
0 u. u.
U 05 O Oi
L Q li- O
I o o o
a co u o
- UNO
a u. o o
0 O' N O
a cj o o
0 -.NO
a q o o
a - n o
l uj o o
: — ci o
I o o o
S UJ w O
r MOO
0 Q Q O
a r- U O
I r M O
a «r o O
' O' O O'
: oou
I « Q N
a won
0 O O' "0
0 <r (J 05
J —• N CO
l a co o
I 01 -5 -
a o a o
E O' 05 -
i' aan
i n q u. o
a «■ o co o
« Cl !D N 'O U.
r O CJ O U.
a o o o o -<
a o o o o o
i) I/O <0 «-* o
n a co q u. o
I Cl Cl Cl Cl o
a o o o o o
j — Ul Ul — O
- O O
incooac
I Ll — ID UJ O L
i iO O O' Ll CD L
.05-0 O' Q C
: o o cd o o c
- N C Cl — iD •
' WMUQUJ'
> o —* o —< a l
) O -O V UJ iL L
IhOW-OC
) CD O U. O o c
1 <E Q O' UJ C <
) M O a M Cl c
J O «r — «0 N -
. C D r ill £
> O' O —• O *0 L
> O CD UJ Cl Q C
> d Cl U. UJ CJ c
5 v O C C C
j -< Cl O O' o c
) Q a O CD c
. — a o O' <z <
. >i)h(DOQC
> O Cl a O' N L
) CD CJ CJ Ll -0 L
i a o co o uj c
)ONM5U.f
li/lOOC'.C
. o in cd ci a ?
> + o c u. o i
) M o a U. O L
I O C c LlM C
J CD CJ CJ U. (J C
' Cl N O H M .
) cj a cd o u .:
> n co aoio*
) a ci o oi o l
i - - o o c *
. -4) N O CD Cl <
)OhOCINL
lO-OOQrf
i a o a 0"0 c
i cj cd cj a a <
1 O a iO Ll N ’
J O CJ UJ Ll C *
■ nrinooc
. CD —< a CD CD <
) Cl O <T C Cl *
) CO CD - CO a L
I O' Cl O O' •*> c
J N CJ CD Q ID «
) —* N CO O UJ »
I <0 a CJ CD Ll C
) o O' uj a c c
I CD N ID CJ O' U
> a - o o o c
> CJ -0 CD O CD C
)-OflOC£
J O CD (J CD a c
) a n a n u
) CD O ffl CJ v C
* o o o o o <
> o o o o o c
> a o c a >o u
> — 05 ID N O' 0
> o o o o o c
i o cd a o cd c
I UJ UJ UJ UJ U. J
V o o
O' O O'
O CD O
- a n
WON
co O' 'O
«■ CJ 00
— N —
a n o
0 . O -
aan
o OS -
O Q CJ
a Ll O
o n o
ITfS'JL
UJ-OiL
O O O -
o o o o
id m - o
a q u. o
o o o o
anno
M J - O
-I - - o
ll tl I II
Received: 77 Nov 25
Here’s my contribution to the Great Software Piracy
Debate. The main facts are clear: software is very expensive to
write, moderately expensive to market, but reasonably cheap
to pirate. Good software is therefore rare and piracy common.
Can this be corrected? I think so, by making piracy—or, more
precisely, copying programs from a friend—profitable to the
author of the program. Here’s how it might work. . . When
you copy a program from a friend you send a small royalty
($ 2 . 00 , say) to the program’s author, who included his name
and address in the program itself. This royalty buys three
things: ( 1 ) the right to use the program, ( 2 ) a complete set of
documentation by return mail and updates later, and (3)
the right to claim certain rewards from the author.
The right to use a program would be valuable for a lot of
us who want an alternative less expensive than the local
computer store but less underhanded than piracy.
The documentation would provide an extra incentive.
Remember that printing is still much cheaper when you’re
making a lot of copies. Of course, this would also be an
incentive for good documentation, since the other kind
wouldn’t sell.
One reward which should be available is one for demon¬
strating and correcting a program bug (defined narrowly as
a failure to meet the published specifications). Of course, only
the first corrector (as determined by postmark) would win
the reward. Other rewards might be for adapting the program
to a new operating system or hardware configuration.
I’m tired of reading complaints about software pirates
and have tried to find a practical cure. Does anyone have
a better idea?
James R. Van Zandt
— O -« H
Cl O i E (J D oJ
OlEOUI 05 X
X
U U U U H 0)
—I —I —1 -J Z D
X X X Cl' <L a.
Z X
a: uj <r
3: aJ H UJ
O > > _J
JO 05 0
II (J ll II
E
D E
05 !D
X Or
X x O ^
i uj <r o w o <x
U X ID . - X .
Oh«aUQ(JiSuIEE
_i _J —
j ~ a > h-
CCZOaOMUXQOUJ
OOClCEEi-JCEJC
CD
£5
_l CO
<0 x
J Q u
C X UJ
: z z o i
« - X u o
) CD UJ Ul
« — H X CD
: x x z
) O UJ LLl
X z
) z x o z
iCChD
: X E 05 X
UJ ID — <=' H
- ID O' CO ^ £
o o o o £ 9,
O O O O O
CJ Cl * * * *
X W Cl «■ * *
r- 1- X x x —
XXuJiU ^
UJuJXX
Z Z CD CD a
> 00 CJ O' £
) Oj C 5 Or O
IOOOO H
> o O O o o
AS' 1 - ' Y
* <r ui * * *
j _ (V) X * r
. X X x O D
c uJ UJ uJ _J 0)
ill iiiu:
l CD O Q <J
j 0 -. D M H M
) o m o uj o
I if) <0 W O' 0- £
IDDDaiDui
> 000000 -'
> 0000 - 00 -:
fli HZ.
<r .. x uj z
t- O -• Ul _J D
h J J x OW
x UJ UJ C Ul X
. UJ X X Z X CJ
O » M N It O' O
O «r N C O X v-<
o o o o o o -«
o o o o o o o
V N N N s ' 1 -
* > * * * ^ z
* til —< CJ —• C uJ
X H X X X r— _J
I x uJ UJ UJ t~ O
U Ul I I 1 X aJ
CD Z CD CD r- UJ X
> ^ O') O') *0 N 05 O' D' O' O' OJ Q Ll O « Cl
. Ll ll : x Ll -_l X a. X X U. X a. a. O O O
> 0000000000000 --'-
>0000 00-0 000000000
» o o o o
1 c iD *<) N
I Cl Cl Cl Cl
. o o o o
o o o o o
05 o
Cl Cl Cl Cl Cl
o o o o o
Page 20
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
BITS ON BOOKS AND A NIP AT NIBL
Dr. Dobb’s Journal of Toothsome Topicalities and Unscrewed
Inscrutabilities
Dear Mr. Warren: Received: 78 Jan 30
About a year ago John Craig mentioned in Kilobaud that
he had lost his favorite reference book, which turned out to be
a manual for the CDP (professional Certificate in Data Proces¬
sing). I found out from my favorite computer bookstore that
there are three such books, and some students buy all three for
fear of missing out on something; apparently they don’t under¬
stand the difference between representative questions and
actual questions. If you have someone up there who has done
the CDP recently you should have him review them. There are
manuals from Anaheim Publishing, Arco, and Petrocelli-
Charter. (The Petrocelli-Charter 2nd edition comes in two
volumes, one for Petrocelli and one for Charter.)
The bookstore, incidentally, is worth a mention. It is brand
new (started last summer) and is an offshoot of a local
computer store and electronics manufacturer, OpAmp Com¬
puters, in Hollywood. It’s called OpAmp-Technical,
1033 N. Sycamore, Hollywood 90028. She has more computer
books than Cal Tech, UCLA, USC, or Technical books in
Westwood. ( She being Mrs. Lyn Karch, the daughter of the
computer store owner; it’s her business, not his.) She also
has books on engineering, math, general electronics, film
making and such. 12 noon to 5:30, Mon. thru Sat.
One book you should check out personally is: Micro¬
processor Programming for Computer Hobbyists, by Neill
Graham, Tab book no. 952, paperback, $8.95. I almost fell
for it. It purports to be a book about a high-level language
that can be used as a substitute for machine language. The
chapter organization follows the outline of a typical college
text on programming, such as Ward Maurer’s or Donald
Knuth’s. But there is no bridge between the “high-level
language” and the machine language; at least, I couldn’t find
one. And the “high-level language” is PL-I.
You owe your readers an explanation and apology, even at
this late date, for some of the obscurities in the source listing
of NIBL. Particulary if the version in the collected Vol 1 is
unchanged from that in the Nov/Dec 1976 issue of DDJ.
Neither Mark Alexander (corrections in April) nor Jef Raskin
(review in May) picked them up. At addresses 015E, 0303,
04E2, 05D0, 05E7, 064D, 0772, and 0909 there are instruc¬
tions with the mnemonic JS and the hex code C4.1 have two
SC/MP manuals (Technical Description, Sept. 1976; Micro¬
processor Applications, Oct. 1976). Neither one mentions a
JS instruction. C4 is the hex code for Load Immediate.
Further, there seems to be missing code, or kludges, or both,
at each of the above addresses: four bytes at 015E, four bytes
at 0303, five bytes at 04E2, five bytes at 05D0, four bytes at
05E7, five bytes at 064D, five bytes at 0772, and minus one
byte at 0909. Most of these are jumps at the ends of sub¬
routines. I strongly suspect that the program as published
won’t run.
I happen to be a Dijkstra freak. If NIBL is typical of
commercial software, I have another excellent reason to
remain one.
If Mark Alexander is still in Silicon Gulch, and if he let the
printout get away without checking it, you should have him
make amends. In Principles of Compiler Design by Alfred V.
Aho and Jeffrey D. Ullmann, there is a subset of PASCAL
defined in modified BNF.# It’s Aho & Uhlmman’s idea of
a term project for a college junior majoring in CompSci.
An 8080 Tiny PASCAL interpreter done on National Semi¬
conductor’s in-house hardware should take somewhat less
time than a term project. #in LALR grammar form, to boot.
Has it occurred to you that “Dope Vector” would be an
P.C.C.’s DAZZLER CONTEST WINNERS
Far back in the misty past (1976) People’s Computer
Company sponsored a software contest for a program resulting
in a new and interesting display using the Cromemco TV
Dazzler. Qosing date for entries was September 30, 1976. For
reasons no one here seems to remember, the contest was a
long time a-judging. All seven (yes, seven) entries eventually
ran and it was decided to award a prize to each entry.
Cromemco agreed to issue three additional $100 gift certificates
and People’s Computer Company will be awarding two $50
certificates. We will publish some of the programs in Dr.
Dobb’s-m this issue we are presenting the first-prize line
drawing software by Gordon French and Greg Yob. —TRW
Cromemco
2432 Charleston Road
Mountain View, CA 94043
Gentlemen: January 18, 1978
I am pleased to inform you of the results of the PCC/Cromemco
Dazzler contest, at long last.
First prize of the $500 Cromemco certificate was won by
Gordon French and Greg Yob (Box 354, Palo Alto, CA 94301)
for their line drawing software.
Second prize of the $250 Cromemco certificate was won by
Barry Seip (Electrical Engineering Department, Stanford
University) for his color-dot-bar generator.
The three third prize winners of $100 Cromemco certificates
were won by R. J. Gragg (250 Polaris Ave., Mountain View,
CA 94043) for his memory tester; Dr. Kenneth B. Welles
(Nela Park Bldg. 336, Cleveland, OH 44112) for his ASCII-
3x5 & 5x7; and D. Kleinman and S. Grumette (921 North
La Jolla Ave., Los Angeles, CA 90046) for their mandala
program.
People’s Computer Company will be giving fourth prizes
to Robert Korody (3131 Homestead Rd. #18E, Santa Clara,
CA 95050) and David Dameron (402 E. O’Keefe St., East
Palo Alto, CA 94303) consisting of $50 in books and publica¬
tions.
These prize winners will be listed in the next issue of our
Dr. Dobb’s Journal.
Thank you once again for your sponsorship of this contest.
Best wishes for continued success at Cromemco.
Sincerely yours,
Robert B. Jacobsen
Executive Director
People’s Computer Co.
ideal title for that service to physicians?
And did The Dragon decide to become The Dragon
Emeritus after Don Quixote Aho and Sancho Panza-Uhlmman
did him in on the cover of Principles of Compiler Designl
(No, because Addison-Wesley published it late last year; mine
is apparently a review copy.)
Watch those bits, 1046 S. Westlake, #1
Mike Fern Los Angeles, CA 90006
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 21
77
ABSOLUTE!^
BY GORDON FRENCH AND GREGORY YOB
Box 354
Palo Alto, CA 94301
326-4039, 325-4209
A PHILOSOPHICAL RAMBLE
Our software is a tool for others to use. Rather than make
a program capable of some special effects and little else, we
provide two essential tools which make the TV Dazzler a
genuine graphics display rather than a somewhat quirky toy.
Once having the tools, no dyed-in-the-wool hacker can
resist using them. In that spirit we offer some demonstrations
and hacks which evolved while we were making the programs.
Bear in mind that our entry consists of the tools, and not the
rather crude examples of how to use the tools.
WHAT IS IT?
The accompanying assembler source listing and assembled
code in hex is our entry. It includes:
1) Two routines which plot points:
DAZL for 128 X 128 BW mode
CAZL for 64 X 64 color mode
2) A linedrawer which calls one of the above routines
3) Miscellaneous routines:
CLEAR initialize Dazzler and clear display
DIAG diagonal line diagnostic test
DRAW initialize line drawer
Look at the code for the remarks which act as a guide to
the operations performed. The dot drawers locate the
quadrant, compute the displacement, locate the byte involved
and mask to find the bits or nybble to plqt. The linedrawer
recursively divides the line in halves until dot-level, then
plots the line as points.
THE GORY DETAILS
A) Prerequisites
The following material assumes that you know a few things:
1) The TV Dazzler documentation
2) 8080 Assembler
3) BASIC
4) How to load, map and access Processor Technology
5K BASIC (software #2) available from PTC for $15.00
B) Drawing dots
1) Use of DAZL for 128 X 128 BW mode
DAZL takes as input the cells:
XVAL = X— co ordinate
YVAL = Y—co ordinate
ZVAL = color (0 is black, 1 is white)
DAZL plots the dot of ‘color’ ZVAL at the location XVAL,
YVAL on the display. 0, 0 is the lower left corner, and
127, 127 the upper right comer.
Warning: If XVAL or YVAL exceed 127, odd things can
happen. This is usually wraparound, and occasionally things
blow up!!! It is the driving program’s responsibility to
check the values.
Page 22 Dr. Dobb's Journal of Computer Calisthenics &
2) Use of CAZL 64 X 64 BW or color mode
This is very similar to DAZL:
XVAL, YVAL = co -ordinates (0 to 63)
ZVAL = color (low 4 bits 0 to 15)
(grey or color depending on mode)
To the user DAZL and CAZL are very similar. Internally
they differ because different Dazzler modes change the
addressing involved. Both routines execute in less than 110
cycles which provides a maximum plotting rate of about
4000 dots per second. If you use BASIC, the rates will be
very much slower due to the BASIC overhead. Typical
of these programs is 3-5 points per second. If the code is
entered at ‘START’, a diagonal line will be drawn. This is
a nice test that all is OK with the load.
C) Drawing lines
The linedrawer starts at ‘DINIT’. It draws a line starting
at the coordinates in cells XZERO, YZERO to those of
XONE, YONE. The linedrawer calls either CAZL or DAZL,
so XVAL, etc. are also used.
At present, the linedrawer calls DAZL. To call CAZL
instead, change line #1480 to:
Call CAZL
(This is at ‘PLOT’ +2)
These routines let you handle any dot or line graphics. The
awkward co-ordinates of the raw Dazzler are tamed to a form
you can use easily.
D) Point plotting with BASIC
Now the fun begins. The demo programs are set up for
128 X 128 BW mode. By appropriate address changes,
the other modes may be used. Be sure to change the scaling
factors. If you do not have PTC 5K BASIC, use the facili¬
ties of your BASIC to set the values of the cells and call
the routines. As PTC BASIC is available for a small charge,
get a copy if you prefer.
Program 1
This draws a spiral with a sinewave superposed on it. This
can make ‘doilies’ and crochet-like patterns. The assignment
statements of the form:
X = ARG (Y)
Pass the 16 bit values of Y to the H and L registers prior
to an assembler call. The program must then save these
values in the appropriate cells. This is a little more
indirect than Poke, etc. in MITS BASIC.
C = CALL (Decimal address)
Transfers control to the specified address which must
be represented in decimal.
Looking at Program 1, Line 20 clears H and L, and Line
25 calls the initialization routine which turns the Dazzler
on and clears the screen. This is called ‘to clear’. The space
between 5K and about 16K is free for your use in BASIC.
The loop in line 4000 moves the angle pointer ‘T’ from 0 to
100 radians. Subroutine 9000 returns a radius ‘R’ with which
the polar co-ordinate R, T is located. Subroutine 8000 trans¬
forms the R, T values to the X, Y co-ordinates used by the
Orthodontia, Box E, Menlo Park, CA 94025 Number 22
78
dot plotting routines. Lines 4030-4040 create the 16 bit
value, P, which holds the co-ordinates in the form
XZERO, YZERO. 4050-4060 pass the value and call DAZL.
To play with this program, see line 9030 for a nice set of
values. N1 and N2 should be small, around .1 to .01. N3
should be more than 3. If N2 is zero, you get a simple spiral.
If N1 is zero, a rosette-pattern is made.
Program 2
This makes circles on circles on circles. Lines 100, 110
turn on Dazzler and clear screen. Subroutine 7000 passes
the co-ordinates and draws the dot. 2040-2070 convert
from -1 <X<1 to 0 < X< 127 co-ordinates. You may
make a circle with the inputs:
1 , 0,0
1 ,0, 0 to the input requests.
Imagine a wheel. On its rim, attach another wheel. On that
wheel’s rim, attach yet another wheel. Now a bug lands on
the third wheel. The path of that bug for a given combination
of wheel sizes and spin rates is what this program draws. We
call it the loop-the-loop program. This is fun to fiddle with.
We suggest small numbers for starters. Note that this program
will ‘fix’ the values so the picture does not run off screen and
possibly crash.
See line 1130. Changing ‘G’ will vary the density of the
plot. High densities are usually less attractive to look at. We
hope these rather esoteric hacks will give you some graphical
joys.
dots/second. This works out to around 20 lines/second.
BASIC will make this slower.
Subroutine 1000 starts things up.
Subroutine 5000 sets up the endpoints and calls the line-
drawer.
Subroutine 6000 draws a frame. A simple modification
changes these to make X and Y axes.
Subroutine 7000 draws a square spiral starting from the
center.
Subroutine 9000 twiddles the endpoints.
100-200 will draw lines from your input co-ordinates.
To get here you must start the program from line 50,
a modification will let you draw a line starting from the
end of the preceding line:
185 X0 = XI; Y0 = Y1
190 GOTO 130
If you run from line 10, the screen is cleared, the frame
drawn, and the spiral made. This is repeated. (And may be
hypnotizing.)
CONCLUSION
Here are some tools. Use them freely. If you study the line-
drawer, you will note the use of recursion and stacks. This
could be done in other possibly better ways, but the idea was
a fine bit of fun!! As for the dot plotters, they are nearly
optimal and stand as a challenge to the dedicated super-hacker.
We mortals will potter about in BASIC....
E) Drawing lines with BASIC
Program 3
You may either see a repeating spiral or draw your own
lines with this demonstration. The linedrawer is under 200
cycles per dot, so the maximum rate comes to around 2000
P.S. 1) Do an inchworm or a turtle. Have the BASIC program
get the commands for up, down, right, left, etc... .
2) We did not have a color monitor, so no color-oriented
things here. Take a program like Mr. Yob’s Mandala (see
PCC’s first games book) and have it output colors to
the Dazzler instead of splats to the TTY.
r' <r
J <r <c.
•< a: j o
O i-. «S
<r .rt (/: <x
t- i — --
i/ .-i n
Q_
I- r> ir u:
•o 4h
t r, t— v —
• >• j. <t
n n, _j —
•c. t/i o - j
. Cw U‘ C. tf TT
*octo ft- u •
. O ‘b. ft- G* c-f
*• <*. 5 •* 1 e
« — «t —
>- - or o
'.•“if* r.
’ -> i *.> «:
•x x < z r: n. a: a.
v- u. — -> o > o
C I J J fj ti) O CJ o
1C U (U) fl.fi 40 J
Ji <?
C'. c: -i
x n -x 'j
' o / it: t» rv fv f -
,r. O Z O 1 -> Z *J
i > r o n -) t
.j
—■ «c
f- o
r: u
• ts
• <r
• M
- J !•
X jJ
_J -o v
• t-
• r'
• o
h- (5 rr
>- o u
O h- -)4?.
Z. *-• >- UJ
<r a o ui ui
I Q O h Z it
a x — u
<£ <X. >- CO _J 01
tr <t
a. a ui uj -j
=> 2 > O X X
•i d
j j _i _J j j
— « «r « < < i*j
• =» • > > > r> <r
«T Nj OJ K .□•<>- E >- Q
w <r n x <x n <r j
!> E- O Q O Q H <1
*•(/)*. j < n J < n u
cs u c- tn r.t a o. ir t. um* u ft. tr «; tr "
t£ tf r- h a .x cr o is. is, — — c tv ft. tr *3 u
--- —• Oj CV 1- C O tv' O' tV O CVj c.
r r r. fj c e % Cs. r. r - t_ <• * * c» s a. t ->
IT 4 . X< e. IP G IT 6 IP F Ifi Ck ir t. M ft ir e» itt t
e r- ir o) o w r. r —- o wtoKccu'tf'tf’
O’ Z. CV CM CV CO CV ft) ¥> ft) ftl ft) ft) ft, ft) ft) ft> ft) ft'. ft)
ft. r • r . ft. a; e. ft* e; c" ts. tv to ft <s» e. <s ft c. ft ft
»r u n ft- ft fti ft'
'T N S’ >| <T T -c
<r <r it
< X <T <3 <r <T
C V Cv v.. O O ' ►
ft c. u. r. pi cv. <j
•< (i -3 U Oft —
« ft. ft P. ft. ft- P>
— UJ O O C. Cl K)
ft U U u. u. U. ft'
t c o rr c f -pcco
t-’ C C_ Ij. CV c ft. c c U C’
uj ft' :»• k — — u r- •one « i. r
► n ir c-1.. — ft o — o — '' t.'
- c ut c*> ft <x s c <t tr cv c
c. c _ c' mo ft ft O) ft « a n o
C. C G R t f- IT t ft ft ft ft ft <T' <r <r c> U* U. 0 If V rr 3 . U' — 0 O t. C C. CV C V v v a f * C" ft >T ft -X n 'J u ft'- i.v t. ft C.. t« CV ft ft; ft; ft ft. ft. lf> CL O' O C * IO <1 ft- <X <
r ft tr p p ft r, e-ft'pcftftft«ce'» i ft f is — — — — — — or : c i> t’c r. Oj cv e c e o ft ft k. r r i*. ft k; ft k k ft ft p- »-ft <r v<7-<j-<7<7<T«r<r‘7<r'<Jirirtrtr'irL r
O t «. tt. ^ f tv- ft ft • ft ft ft) ft) ft ft. ft ft- ft ft, ft. ft. ft. ft. ft ft ft ft ft. ft ft. ft. ft' ft ft ft- ft. ft, ft ft' ft ft. ft, ft. ft ft ft ft' ft ft ft ft. ft - , ft- ftl K ftl ftl ft) K. K, r. KV fti K. ftl ft - , ft
ft? ft f. t f s t. c. t; f. c v^<rc<i<T<r<rc v <r <j si csr<r<rc<rc<T<rc«Jc <7 c<- c s s <t <r<j<7<7<r<r<j-sr<rsr«i«j s
Page 23
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
79
<T
CO
— __ O
c. ot-
«j rr cr
C» U. c£
O x
I- cr
i«i «t
u. X UI
:r « k»
U. « (i.
lO L3 «v (U q
—< r- <r •—
Z O Q Z
<i x -a <c
C. If O
K' K -1 <? <T
r~ r-
IS>
o - 1H
ft. ►- UI
O t'J C'
ui Cj .s no
<r*-»'jouor>
07 J JJ JOO^frhl
J « l !». cr. i r _J <x o to '
tn fr
••! rc n
n ■"> <r
•o x
(— — u
r- io rr
O <t 1«J
W RJT
O ■7' -3
3 —« -J
*— «T —•
JCJliJ
_J cr
o o <t
u. ui
uj •-• :j
r _= x
» •■*! f-
•- z »■•
cr “» vj
n o :j
u: c <
«. UJu
> > >
ooo
S’ •«: x
<c f— i—
U. => UJ
X O ft
• n
o (V x
»- o ♦ O rr k f-
" o. (r ii >/i < ir w O —*
• (iJ ■=> Z >- HI <U rp 7r Z
n. (Eh aoo J • r~ —
u. u x cn x >/) u — o. rj
a 3 C Cl J J _J_I
— _J -1 ~l JJJ'-'HJJf-Q
x t. xirx<x<tr>m«-c<i.t,o
_j_jrn_jtncjov'>oi3cr"-
t. u cs u< t< u u ir <s if <5 tn c. u u c if^ d t. k>c u a u ^ c Cs- ‘X* <s u< * if< r u. C. U «* tn t. in ir
if u cr r- t- cc n <r a\ rs i<- — — cu o if k> «r tr io cr- u. an or ft <r p r-cv cm if k <t <t tr it cr
fv (». f. f- ^ f. f. f- r' a x ;f< x j o i> o » to a. x / x i ff o x> o c’» <r< <"*> ^ o. cr> a t*. n c cu tfc
f r. h m ic ? *. i c r- *v- t ? r r r ts f i*’ Tj r- rv f ^ r- i f. i -s «?. is. •* e- *■ is- t*: «?>
U't. IT h U,Mf G IT 5> tf' e, U C. IT f b C- U f
ir mt aw; <* e is — — cv o
- * fl\ ^ ff> j, ff I- IS f y, ft, r 4 t
s * »v d r s —
u/ cr r- r o
cr rr {j o
<r <r <r <t
k . r nio
<r r <r <r
f* * f» K i» ►. r>> * k k r* K K r> K) r
OK, Uj r u. S. « MJ R- IC b. f; C 1
u. k e e. u c. h. *4 k: oj ?:• o u,
ff' <rr a cv k u f: cr -*<rc> «t wocuiior.ra f ^
b • li • f»- O C' < C O K; CC W (« lc O y io c O G C f- *5f
» Cl C* C Co C O l\. (V (• !»’. <3 U' U If- If vr (K O O O U O U* «T. C K If 1C M, a o U. C If MT M b t. — C. C C • 4\ c • t c
r t.> r.» lhjuu c.' o o cw> o t* o o ir o u o o o c o r. ci o (f o o r n n u* g- g; hi u: hi u h h. h. h f- u h t
D K. K: »•, K IO K • K, ro K . ► . K K h K) K Kl l> K IO K1 r, K) IT r f, m IO T « h. K' K 1 C K- d h K- fi r l» »• pjt
cr <i<r'C<r<r<r<r<r<j<r<i<T-cr<r<<r<rs , <'^c<T<r<r<:<r«r<r<:<r<r<rvcr<ir<i<MT«r <: c <r <: <r <i c
rr
w H >-
-I O <T
M 3 ^ _J
M l/> If'J Ol
<r u. ~ < co
o o >• > -.
^ • .X) IV) 33
O O (S Ili.>.
7D ■=}
2 O
•-< 2
M
Z f—
o <
U Ui
<t O to
fS. 'C —. cx <t
S- CC Cj <t — -t)
— <X H Q.
z zm:i/ r
~ <X -3 X O ~i
Z -J
o <r
—• >
to X
• a: c.’ cr '3
I O M O
i -I <r J x
. a a o o
WHO
— O -I
i a o
I- CM
»- <
cr r -c-
' J cX
cr> •-«
to x
ui
a <r
_> >-
nhX2
! (I «X
'-O z ^
j|li hX
rr u. m
I- O UI HI
[<J U! < O
u I t/1
<T I- 1 -
O
O '-J • »-
JHHO
n? 7
• a. «t
s: i-
co o to
rr o z
— o
U. X o
> t-
>- to
• I ul
<X I—
— rc. CM is.
aJXhWCltviCV
• cj<r • *.?S)<r»
<C C l Q t <t CVi a (E .D
XXX o
J J J X
>- \ -■ G Q J)
ozzxoz.vx «*.
• 31 :c o tfi
I I - -
— -J-i-J-iO'r «>o
- xozirooszc<t<i;<i.zz(xo<i
ui js<Krsuciircrirx"5«orc
<t —* O Q
> ►- - C XM
O Z X Vi o z
> <r _j q x -j
^^cS)l^e fc ^^Glr. 8iouinsifiMi.s«,Gine. if\ g- m <s> in & ir i, m t m c ire is it. c ire s» ui ^ u'<h.u. v-u ^ u
cot^r-trtticr^sc^—— cMCMfOK)^ , 5rircif'W’crr-t^crcof7‘^ir , cc;—^-(\)cv)K)K><T5rir'ifu> u? h h o tr (r> cr. c^ ts. — — p; w r- r> v ^ u' r ^ «?r r
i')icK'K'K)K)io<T<f<T<j'JT<T<r'f<7<3 , <j ,< g < T<r<T < T<r‘3 - <T<7 , uir<if>if'uciruijXir'ir\b'i/ir ir\ u - ir\ u l. u - m? o cr u c w 'r ^ 'f 1 1 >c cfv^xi u. >
n ??• « is r k> ts k; !■; es is is n «s «s. e c. k, ts i^. e? csi »s.' «s> Ci e to cs ® <s e? <s. ft. ^ e F f <v«> t f. r *S' ci f e r- it « si i" s e •
C If Hlf‘ C U H lf‘ G ll ■S lf» fS If- <5 IT I*.. ITi G L G 111 G If IS tf’> C U ■
“ *-— CM CM K* K3 <T <T I/C IT \l> \C r- ME ai C (MS C5 P CJ
rs k is r r i Mt « v j,
K> K.
-9- UI
iS' is ir cr r cv
<r mv <r &
x u <■
s ^ -r
Pv (T K Uj (S
CS <T 5T «/ \C
U G G IT- U? C- S k S
k K S C\J <• (S) CM V IS'
— IS l_l Li,
Ci. c. r- (».
cr tr <r t*. k »o
o b i o <r q o
<r — — er cifP. *-<no<r-ff'
M K - k H 'J U CJ H fa - O IS» C-
-* «r cp u. ii. a u ^ — u. /»•
n p b' c:.- vi r- .v l* 1 — — — r. ts cr xr t»
<r cc - <MT r
r- t-i c.-
<i<ioii;-*CM'fl'r'r't^t't^r-r'r^r-r-r~r^r~r't^r^f , ^r'p'<io'Sj — c <r p < o d vi r < <r s <r s s p n: <r if o c ui r, - (,»■ ■«?
iriioif>irii^i^vtotou,u3U3c^ccv:uj»2)«^\^)cf>bCtr^wPc^«^u>t^r^i^^t-r^-r^r-f'CC'or'8cr cr c ir c tr. (?■ n. k or it & c c (T oc
io K, r. n k. r Ki o rr ki r- io ir, k) io K) io G o io k ki r. K) n>) to k- i-, ci k k) r. r. o r, k> k: k; tn r) r, o k, o r r ro f. k i* r, k r, k-
^r«iir^^^c^cr<Mr<crv^cr <r <r ^ sr <r <■ <r <r <r <i c' ^ -Cf
t- a- ff> <t o cn ir m o !«• - o r, ir u u »z:
<r o- rf o (Too' r*\ cr <r <r <r <I <r <r <r
X- K K h'-K l*J l»J K’, K h IT 1^- K f- K 1 K !•',
->r<r«7'crf'ff<T't’-<r<r'<r'cr-«r'C5rf
Page 24
80
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
n. a.
D <X
<r _J J
U4 <t
> <c
*. :< a
o .a _i
j jj
r x <t
_i c/i rj
xr — k; x
— — k; p}
■ft! • —
cv y
' — V
J O <£
' CL >7
■ :*j —
^ i- rn f- <r
I —• < '7 ^
r
»-• «r o c* o -*
f; i a a a. a.
^ y *i S' in <t
- Cl <r »Qj3X<t •OX* XT
*-*-:> -J '£.->x M) -i y r> xr >
X. > O OC Z O Z O X Z. z o *. o
-J S' V O' <f ^ ~ s: *r <1 — c; — v
_i
>•
■ U. A
i*
*” <£
SO <r,
O <r
o o
a:
o </> «
v e »Vi t
V V A — I
— — — JO'
>•>->- 1/1
<t
«* <* v o n «
z ■
cu» c. c* u <
y y y. >-
v a v o
- Ul 2
>• v V. f_) — <
a. ■
o.- k< <r r* o
•o '»J 1*1 O' _1
wi t/> v> u.
<r <x n
o o o z >-
<1 ai
Vl <T til O
0 '/) -J
t C jJ
JO Z t/>
^ W O <t
_J <* A. O i.
p'- — c - n
:-j a e> 0 ui
</> to —• < qvi
< -T -J _l < <t
OIOOli. U. & I) o
— <r «i x < «c r _i <r ►. a
? u. a; r ?. r ar >. j < oati
5 XO-J — V. C7->“30 _| O *> *"3
■n f-
<£ uu
X il
J cc
t- o
J
— o
*
uJ <t
o r
x o >-
I- H
Z 7 Z
Q, h« H
=» O =5
a. cl a.
cc : j iv
* uj z k .-q o
• 10 o • • •
xo x.x/xs:xs:
o «- <*i
71 CC V:
« UJ <
X > CJ
Ci a
x :> _i _i — t>x>»-
t>OZOXXXOZOt*J
f j-mv jw jfHror
T
Ul X
a.
o cr
_i —
cn <
cn a.
o n
a —
If. if- A. If* 6 * Ifi <V
•Q-irinififf-r-tr
ui ^ y . t if c» if* c. u' r u c. ui s it s u \ p. if^ m e: in t u■ it o it Ci tr* a. tr- u. ui m «. H , v» «. >» w ■ — - — -•
® ^* «* «r. a. — — cv - — oc y kj <f v u'* if n> u> r- a: coff*pw 6 i-*—c , c^»OK)<r^»'
<r <3 if if. ir if ir in it ir* if* ir in in to w. if if • in in u u* ^ «3 w v w ^ f f ^ if c *f *i> ififur-f*-r-t*-r'-r-r~r*--r'-t'-t^-
C if <Vi If. C lf\ <9 IT O If. ©« If* C- U ■ ©» U'l «S U Ci. If > 6.‘ If* M
A. —. —.*.«wiin«T<ru-*if\u?irJC*-r*'OCOl. £T. <t r
- r-r-r-r-®
if' -e ir* c if
•q «r <3 <3
*c *s < «r if' «r <r
<r <r <r *j <r <7 <r
IT IT IT
<7 </ <t
6 . o »o U. <f u
e» u. 10 e e. r-
u.
r~
rr u. <z cc. r. u/ in
o <r a k &. <7* o
CV ISC' t.
?v e- s b>'
— if fit u p> x u 1 u. cv ci 1 10 p
c- — p- <y «<tl mi <r u r- cv r-
ui t«. w; <r K u w <r k c r </? <r ic
cv < jr u. il <1 J' x o i' y u. u. o
tx. If K) !»’ <1 01 — C K' — J
<v <r cv ■q - cm cv cv r- C' r*- o
a. a: J or OC 00 JT t*
<r<rv<T«r<r<7<^
v<T<r<r<rc<?<r
— c ir if if* u n «
IT IT IT If U' If ir If
<tsi
w^«i<r^<rv
ironu-u. is-cv
if io«rif ir if if if
qcq<r<rqq<r
p. ^ iO if if if if if
ifififififififif
<j<rv<r<rq<T'i
<7<TC<7<r<j<r5r
if v" «f «r **■ if if <r
if If if If If flf lf
<Tcc<7«r<rcc
tr « n ui u c. ► it
If If If V Itfhhf
^c<r<r«r<iX'3
qqqirctMrc
(J* c U! - <1 v 11
r- r- oc cr R> x
<7 <j <r «r <7 <7 <3
c <r <7 <r <7 <r <j
<7 *7 *7 itP X f*OU
or cr ir or oc ro cr 00 a
<T<7<7<7C<7<7<7<7
c r, q if « if i£ if
<r <r & <r <r <a tr <r
V <7 <7 <7 <7 <J *3 <7
q q q q q q q q
«VG
; f . ^
I «J. *X <3.
•OJK <t >- ^
; »- *X
: «o ^ a 00 o
- r- .-3 r- 7 »-■
/. Z Y > i. >
• c — o a o a
j • —0 — 0
J • o otl o
V D C C
'J <r <r ?'
<r X tr <t
• I— 1*1 •— fx’ ►-. I-
; 1/1 7) q 10 <t w
<r a. <t o.
Z ^ uu z
' o o 00
j •' x rr>r -
f>- Y>
i—■ ■} n 00 . 1 -
7 - O - n L3
o n c> q o a
ilf-O .i
tc t a-
C *•.%!« «j <r
1 - 1 '* » M •
)»/»*/}<■&>- «J
-^«rz<r
O • O »
Ci yc ^1 >- o ai
. c _j — c <x (j~i c t> n ■
: T xxdOClOOw-iOC.i
I O w J J <■ J VO _J X _1 :
*t j. .Li
*> o o
U X .c
—• r.‘ a x n ii
•t H O U. <t “v.
a. CL t— C., h*
It X Sj) tc.
J n
\ O — H-
t <t 3 -u O ?
l- a. O -XX
r- c/ <r _j a t'
<c m o I— H-
' . _i v v* r 1.1
- J \ 'll «j •=> X
-OX o tf
00 O 0
■ 0 • • Q M
. * 7 i u x _i n j)
— j
■ a — 7» T. h _l T .
av or-z.xn._xic
IQ J * V. 7 Jf/li
u v >-
on n
<. <x
i - Z
1 o —• '
r t> i
'•J «i J •-
tc Z c.» c
ft z »-•
« /i M
U‘ C 3 Vi _l
• • JO
c > >t r u. j
p — — 0 r
a c u‘ •. t
rqq iol' if ifht a
1 Cv 0 cv c - c\ c. o a <\ ;v cv c- 0 o’ ui. cv cv c«
a o ■— -> x 7 - y- r> > r»r>.r
O O z C ? S> O O O -
ft O. _J I —• f
t- U‘ »S If *\ L* •* U *> U. C
r< i*. - - ci cv r k q q «'
x: H K; Kx M fO K| Kx K. P f*
uJ Q >
Ul 'sJ
< Q J-
z n
UQuJZ
o * <r
H C W X
O *-
«t • X •
< -J C x r a.
o <s cr •-* > x n tn
z vz> OU.TD
-a 0 •-< v v c <c a
lf> Ml! & Ifi If* P"
« — — <\ cv o k) q
qqqqqqqq
•r
■q
A
t.
IV u
<7 PV
- rt r — <t r <u. u <rr cl ui
L\ *} C . *• «•- -4 I*. U i^U. q k. q u
— C“ — 7T " U C r (T ?*
c y i< <»* o c u o
r- c
► • c K f, c
c f- c t r- sT
1*. u. c 1' -
r u p • r
— cv cv* u. o ui cr ic m
<r •* c i« r cv r o & a
Cv c c c* c. C*l r. cf IT ' L
UUL Ublcbtx Ii (1 U li
KU, K C P K~P.K K"P P ►.
qqqqqqqqqqqq
u. L" p ^ u a c t_- c 1. c*. u
UPAtqprpt. atp
r q q q q q q s < q q q
qqrqqqqqqqqq
— c. tr v r* <r n u u u 1, u
q qqqqqqqq q s q
qqqqqqqqqqqq-
«. u (• u- L b. 1* 1. u r — <3
— — — — — — — — —c cc
q < q q q q q c q q q q
qqqqqqqqqqqq
u v r 0 c <i a c, C - p -3 u‘
CfCOCOCCOPP P P
qqqqqqqqqqqqq
qqqqqqqqqqqqq
j f <7 o Cv — cv q if- if r-
p- pp P''<r^< 7 ^ , «r« , qr
q qq qqqqqqqq
q q q qqqqqqqq
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 25
81
COl'i&INED 7 ALU
'JQ «J
- <r x
1 f- <t
j 4 xjj jr
T> O O d
O O O D
I— I- I-
«r ^ a. — —
x u- o x >-
<t it) Q < X >
ai< e nu j.
—• r- x. r» —• t) r> v r» o :> r> *-• :> x > a
>CZ0=»^>0I'0Q00=>0^10?
t ?: m r »■ w f < *• r r >: *- r -a
6-uMf M-F. U'SU l*. IT P b P. IP ft. •» ^
P P on cr cr CT P r —• ~ CY C\x x <7 <7 ir lf> vf
— ~ —-tv <x* tv. CV. IV P C'J C 0. CV Cl IV CV.
cv cv tv c cvi o o: o cm c\ o cv* c a cv a c o c
•
•
_
•
•
o
o
c
•
or.
X
X
•
o
o
o
•
Id
3 UI
o
o
•
u
»-
u
o
•
<
l—
UJ <
a.
M
or.
tn T
•
cr
<r
<t —
X
3
•
>-
a o
o
\
•
o
>-
O tr.
_»
x;
•
-J
<
z
O
o
_J
•
CL
J
.J
t/i o
CJ
X
— CM
•
(/)
u_
•
c «
• *
•
t
*/)
X
•
Q
J
z
-J
o x
>- M
N
a: rr
•
o
o o
•
u_
«x
>:
1- f-
x»-
•
o
r>
r
_J
cr
o
<t
V) «
<r <t
•
**
o
<t
fd
u
t ti
LxJ
o o
•
Q*
o
O’
_J
cr
cc
a x
U<
'-xl
•
Q
<c
t
X
•X
E rr
1-
1-
o n «
•
O
p;
UJ 3
<t
<X IV
■s
—■
— £\l to P
p}
<T
<1
«: z a.
•
*t
<c
to
k-
<
l«l
P* O
1 t
T t
z
X
>■
X
>- x V- X
>-
>
y
—• ■— i-
•
o
_l X
o
cr
o
•
1-
X
SI
<r
•
fT
n
b)
cr
X
•
cr
o
a g.
X
3
(?:
•
<s
T
_J L-
.1 J J H J
<• X
X.
rr Ci
<
<*
IP
<t
<r
«rri'
lUf- r>
<r p-j
or
t r
cs.
•
ir
:*J
—J
4T
CC
U i
>
“> f- cr _J Uj
d ir co
CO
p. cv
«
«s
c*.
IV pv p. c.
ts
C4
t
l at;
•
<T
O'
*t
VC
z
_l
X
>-
o. WO
u to
p n «r
•J}
•
—•
■r
ul
Z.
•
J
A
z
•
c
-J
•
_J
J—
<x
•
<x
=J
—>
rr>
rr
-J
cr
r/>
y
s~
J E J
* r
y
V. -'
m
rr
3 O)
.Tl X
X
X
u‘
m
til oi a a
ro
tC
.o
x a, u
•
tl
»
rv O’
o
r>
i
o
O
o o o o o
o r> n
o
o
o o
o a
a
Q
c
o o n o n
n
o
Cl
n p a
•
tr
Q
f.' »d
UJ
UJ
u
<r
<t
o
u o u o
y o
u u ui
cr
or
uJ
0.
Id
«
tr
n
tr
T.
X
o
o
hJ CxJ
o
U-
— o
<x
O
Y
UJ o
i.0
►-«
p- _J
-J -J
o
cr
rr
t*j
Ui O O P
rr
*
«•> C" >-
*■
L.
'i
<t
•
cr
<r
y
_J
O «t
<t <r
o
UJ z
T l* 3 T
T
c?
o
<r <r x
•
<t
rv
Oj tP
IP >
0.
b")
f-
I— *>
r> ?
-j
X
X
o o f- >»- K -
H
H
?.
1 JO
•
r.
f-
<r
-J
<t
•T
—
•
•
•
•
ip x
>- tv;
p.)
X >■
X
>- x >- y
>-
X
>
tx. fx. ix.
• •
•
•
u;
H
<L
tU
ui
•
•
•
•
•
a
•
*
•
IT
Cv
u
c.
u <
c:.
ir &.
U) M
U'v
s;
»P r.
u « b.
U>
Ci
IP
O. b S.
U\ u
b
c.
IP fS
IP
S
If
CS
tr
C
u
•j,
U’
C-
If
e. tP <s
IP c-
IT
u. U
c>
at
t.
iO P
p-
on
rr
O'
«r. o:
\ —
cv o.
X K *r <r ip.
tr
VC
u? p r x
o c
O
o
0
X
X
V
u
u
VP
VP P r n
o o
C7-
o
o.
cv
CV CV) cv.
U r>
K p,
IT
•D
X
r.
P) X p' X
X
p
»■
K; P, X
r, x>
X
<1
<r
V
<r
<2
<i
V
<3
*3
<T
V V V
1 *T
V If L"
L-'' IP
ip
o
01
o*
o
tv
cv
cv o.
0 O
O:
O
cv
tv
o’ tv- r. r
c
t'
c
r o fi
0 o
0
cv
c.
c
O’
pi
o
cv
O
O'.
o
o :
o
CV
O'
OOP
0. CM C
rj c
O
o
. W [,' tf P P ' Q IP O' (x «J*
<T «. ij IT U r- u -3 <T c
0- c. T. — —
— tv -e li vr p <i'r<r <r<r<T<r*t«oC'i»'
U' L' (»' U* UJ l’ - U tx'Cx (.1* U. U. 1/ U It. h U It t«. U. U U U- U. U U U U.
c<jv<r4<rc4<r<;'sc<ic<r<fl
!S — C . »■. <T If • V, P- 0- O
i> r •- r f. r m, t f to wo r k * ■*. sy if
U ' b ' u u it ip 4i b ir ip tr u' u u if b u tr a
1/ If U' 'I u b
lx. lx U. U- U U- tx U U. It
x r r p r “ • e " <s r
if u b u if. if
If b b If li
v<rr'<rccr<!<T<T^«T<<:<<!C<rcc4r<rc^<JCCcc<j<rP<r^cr^<r^*i'
*■3 o »o
>- »-* ve¬
er f- <r *- I- **:
•«j» _
o ■ o
f- x v vr
'll o
^ f- f- a
hxJ uJh
4 4 0.- —
t- «f-
Hi L
C9 • f
—• it
■V <T
»xj x
to <t
3C r
r
o UJ
i— t
E X n E o Mm
► • • #• » • < •
i x ■ j _j ci x u f <* ui x •* o
m r h o a.
<t u < x e *. i- rx <r a o<xe ro
• • • » • * ■? • • » •> * • • » • » • o.
«<t jj .i j^tu aa *-• _i«xxc_)EQ x<r<.xo_JQxuio
JHZUJQZU<j|Q.<UQ<:iJ!ilJirtUlIlQ *-
X X
*>x>—=»x>>n >rj>>o>«>y>wrn
• O Z O :> O Z OOC)0-OOOOQO'>OZO.3r*
:»y:EfHi;j:*nr <t f r <t s: r. r •- s o. o
J> O Z O > li O
*■ r « r e w >'
X >
z o
— v
t. r> :
rs o <
to f ^
« > x > a
• o ^ o jL
: > - ~ r *>
— r'X>«r>x>>o r'D>>.'nr>-.r.>«
^>0^.0>0^.00t_)P. OCjOOOO oz
^ 5 — > * s nvcrrwn i «
x x
to
o o x
> x a
U • • • li. **«*o • • •
u' *» tc c. b"- r ir «u »p *: ui co u< p- u- (si u p it- r. m u> e. it. Pv ip p u. * u mi. e> tMi c- u 5. it mt s tf 1 ' c. it t. ii- f it p umt t bi u if t k Qm 5 if> ^ it mt t> o u.
p —c\ r it i <r ctPir v m-p ir r t ff f. pt — — O' o or v <r it ir- w. u) r- f tr tr> <r <r P- p.. — — o ci k r <r c in i/ vc vc r- r~ x w o* o p -« wcr o <r<r ii'ir «ni>
x x tr x x a? x oo to o, to je -x o’ to ou cr i « o c C' c C' J> J p <r crji c. tr j- o, iMMft c> 4 n u \ u &.• r. i: ^ -----
- - - - - - - - --— ---- - — — — — pic o- O 0 O CVO O O! O' O' O' O’ C 00 tV'C tv O Ol CM OCV CV O' O CVJO.CVO'C cv
<T
c
P- V 0-
Pi c X
Cj
e.
•S3
IS
to —
IS O’
<x
ui u: ir f»i u.’ ic K: if «t r < t p 1 p 91 k t* i*j v *«"' u.’ ip tr
f H' <r w ir. (v ir mt t mi itr~a it o s o «i t ft
r*.’ >xi p vr l-j if r~
CO- 0‘ <4 Cv O' u
5' If-’ O' U ll' If K, |.' K
P i/ O L ■ 0. L o
r» vr p ui u, \c p' uj <r ► <t •»■ o p c r t tj if k *-» »f ir
0 «r r <r cu. c u r x u p v ir p c u cv c st ^ c:
tr a a <r cr o u - u. p. — o.
O' O' O (7 O' O' O' C «T <T <X
vvv<)'Tv<rc<jt<r
<r<r<-5r^<i<T<Tctr«
u «pu. o <t cr p ui i>
<r<r«<<r<t<X<i<r<i
<i c <r <r <r ^ <t <r *r <t
p.- — o c. o Cv * IT vf p
cn o. cr it a or o.- n a c
CC^C'JCCC^C
» < r 0 C'.xiU t ok
a, x cr a: ci <r ir c O C
<3 c c c <: c < c t
■c c <rc <tppp<?p
^ u a nr I) ^ cr «. Q: O
o c* c V’t; t f o o o
^ c c c c c <r ^ c
oi» c — t. ►. >r p o O' <t cj
f.rjnrrnc'C'rnnr
«r < c
r.) Cj U. p —< K -q c <r
r r c. u* ix i- u u* ir u:
•x<^rc<r>j< r c-y<c
<r <r c < <r «• <r <r <* <?
Page 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
82
o
<
<t : d X
'£. X N
f— <t rv.
•. * «T
O o O Q :
M n
-T
Q -*J
<t rv .o'
rxxxxxxxJSvo vo
-T — COCVS(S«J®VOin to
<. ® ® ® *■ — ao cv ^ tv * cv *
> u •- o => o
• s_ X Cj O 7
I U J <t f -j
. 1 : x.in
.7 o x <i
mx jn
<r o o *-
u 'p <7
J a- t .r
•X C '
. y a v.
JO>
«] <1 <t
itror
<£JO
<r t <r
7 cj .
<r x ir
f- -«J .0 h di'
l— t-; _u •:? x co co ui a co co cd cc tn 3 to r»
"lltown QOnOOQQO Q wow
<r q. <r a.
1- o »-* o
t u> f. t' c. it ^ it* e. tr f u. P- u - <■> u r> u *■" m a c. if- c_ u' <u u u.
/*. O' C f, c K) KP tr f l£ »i/ h h O’ O O'- C I* • •* ' —• — OI 0; F.
r c cr- o j. cr o\ o o'* 0 * <r> c cr> <r\ o- rr c* (r & o &. •* | *. cv- * v %
S', o o: c\’ c o o: o 1 o o cv o< cv (v c c\ oj cv c-.t c o' cv »•) f> f. to f 10 f.
. c. u. a. 0 5- u' ; •/■■e. u. c: m ® m ® tn &. in <& m e tn c* in ®
> <r c m u' u) u. 1 h p » rr tr /+• ®6i——•cvcv* toio <r «r m in vo
' c f e 1, ^ ^ r c r t t — — — — — — — — ——— — — —
, c/ o h r r r.' r. r. r. ► f *. nion tnnioior tn tow 10 to
in in c*
R (M?
VO VO P
o>— —
m tn ®
ff.p p
to VO VO
Cl. — —
Pi Cm S. in S.
— to in <T «T
IS P P CD(^
— C\| CU (M (\l
f . 6 in R R. C. IT IT
incuot.cv^f-*T®P
vo— in in m vo p <r
— ® cc 5. «r e. *s cl
r. e.voco<tiocccvptocx,«.vou.inocj
vo vo cr o p cr cncrvopo.^w^copco
c> is- ■>* <r to to to to to <r to cw m m if. Mv m
ui fc;-«T<r<i , <T<T5p<T<r^-is«T^r«T<r'*T
c.' c< r»i ' — — k. vi- p cr u> o c " ■
u. vo vo p PP PP P P p r p pni
o', in u u > u. u iT> u' if mu u u u u »
<rc<r<T<ic<j«rc<r<T<j<ic<j-
3: y i) cr a ft
l u in u if u
<r <: <r vr <? c
T 0 rr a. o o
If ir u< in u 1 /. u L
C'- ?, <i<rvr>r<iv: *r <1 -
a 3^ O' 01 tC’b U. U. ■ — cv to <r If• VO P e~ P5 K - P' IS
a a o' <rr\ O' O' 00 <<r<r<r<r<r<r<ie
11' u if. u' it it it u u inininmminir. invoppcoa.
<r^c<r<T<rc<rv <r<T < 7<r<T<r < T<r c <r <r <r <r
O — to cr
00 — l») W — <V K- 5f _J <X — CV to <T to
CO K (/) W P’ P' P (»• tv> X u: > P P’ P P' K :
J<<r<«<r<r«<tar;j<ic<c«r«r<t
«r cc o o o o c o o 0 u on o o c o
X >-
>- >- _J
« O O -I
•-« r o <
•x o *< crj ^
~ n x >- <?
x u
P ZOld
lij alQ> •
f/> a. <t pj •
O _J -J.J
o ■«* <r <t <1
• r> r>
o
P- .X
l«i X
f- X
— o
=J w-J
<3 X
O
O X
U UI
_J J ^ Ul
<t VI o > 7
-x v 'ax tx.>- a.>- n a. C. 0 _i <t — o
— <r><ro<r<ro<r_j—. —. <r p- 1
r> hocapnciH a _j 2 m u _j:
5^ cn c j <1 w j < if. tj — <r -> x o ■
o ^
7
73 «
O O O
: — a =>
U> P-
-1 — X i
V V) iJ • u
•v! O CL a.
< a. ~ —
uJ •
11 • U.
«J Z. U.
X J o o
P- <t
r> H ••
7 >-
a — '■v
p j j j
■ o < <r <t
>
X P-. NJ
J* -J
*X 3
• fi: —
O CD
fv ta
( *IU.*H
p- o o
>• t
_i r n;
PJ <4.
woe
<t t
O X
P- tv
P o
1/1 Q3
a. •— x
H tn
'y> jj oc
o cv
n _j >-
<x \ •
3 P T J
o» ui <r
S) 7 7>
alU«X
XU. II
POUIU
3 V
fo ui *« n
P X w
< p ••
t.'* h:
Cm • H
JPPO
3 Z 7
• a. -r
I- >7 t-
(OOW
X o z
— o
U. t u
c
.•> p-
>- cr
II UI
«r P-
- JP
<T —
II > 3
o: Vi 7;
— u. —
lf» u.
O Pm
x _j «r
J1SU
X o
r.)
«t(T« C
' X> •
X X c
— is. cv ca v- o o
UIW <T O TW CM V \ M. S i 3 i
• p. «i • •. p <x •• cr it a* • • o
p.a <1 r
o 7
^ — UI
1 XOO 'J Ci < 1
< m r > *- r. m > m — n
■x f joxzr.<O^N-x«x
UK i-«t J r <tn jno k
w. .— — u o 3> x >
• o— K-Czacar. OZO'.
ii' j r -t r x s <r >• o *r x a* o* *3 — c
U C. Z
i ft! 7
Q • •
r» « ^ii-.tii' f .u c. if. <s. u r. uv c. I', r- u> & u' e» if\ c» if ^ 10 51 in & in u ir c» if. 6 . in c. uve in is me u> e. u
to to ^ «r tiv m vo vo p p ir t n in e» cj —— c c-. r o *r <r u iovcmcpp axtMTiNN--cvciir, tn^«rinif vovoppornr
»fv in m it it inif in if mifinm. irvovo'ovovovovovovovovow'Ovovo'0'ovovovoppppppp'P'e'PPPPPP f ^'P r "
cv, c\' cv n p' cv o* c • tv c. o cv cv cv cv cv 01 cv 01 cv a: cv o 01 cv 01 cv cv cv cv cv o o> ci c o. o: v o 0 o- cv 0 c> c»- o cv oj cv o: cv o
_ m e. in u. m ex m e* m c. if
vo vo p p- - --
(k If. Cv If. t. IT & If L If c . II - u CU U U V- a C-. U
orrr’O'O'^ea — — cm cv to to <r ^ ir tr *0 vo r- p cr c
p p p p 0.' tr xi x j.‘ a- u, vo a no a o', a w*' "• x m i
CV O Oi O’ O' CV O’ O. O' CV O' C o* CV Oj CV O' o. c O. O' c
<r v <r «y in
■q <r q q q
IT ?,•
Ui
<T C C' IT <T If CV IS
<r f, <r f q e f
ir
<r
— u. o c; c. o to
f' U U U U u. t>.
1 • o p <t rr c\ <r * o o
e t> 9 t, itit 10 y r, u
ere? <r u to f
c. bJixciO
<r — — t rr vo cv — <rvo<r — cr
c: e — ui p -jJ o tv p uiu r l
— <T VO U. U. t*. e CP U VO P P P CV'T — u o ^VC-P
f p uj e. e <r < p u: — — — n e- f o q- !■ p '--J *s.
u — «r m cc c> o u. ti w » if 0 <x c.
CV O. Cl O Oi
u ir tn if u i»‘ u u v . if ■ u • u ■ if' u
<r <r<T<Tqvr<r<T<jq < rirc^c
u’ e to f- K’ tj f o k. r to m n k
O to to K- to to to to K.' F. F F< *r> F'
if m u u u in *n u x» u in in if. in
kj f n t; Ki r F/ vo o uQuif f vo
to to F F F. F. F) F F F F. F «T «T
if uv if• u. in in ir< if' in ir if> if> u u~ in
<r<rc<r<rqq<r<r^<r'Cqq<r
p t o u s e e. 5 r. s v f i>- o
q <ut <mr ifinvnirininirin
U li lf U t u.ll If ll'lf li’ll H U
« n o i«i u. & - <pr> v p x a 6^ a
u if m m m vo u ? u vote v- vo vj 10 v
ir, u if u. u> m in u tn iT'm in u mu
c q <r <r ^ ^
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 27
83
U. <T trl UJ 9 sp U1 tv V£? —
<sT«7srr^^CMPCsTCV
B00CMB.inCM«Tf~CMO
UJ O VD '.•! £M vf •— <7 UJ II
cv,o<rcjoo<Tcv<rr~ tr»
p- sr co cr> cd to to ^ cv
f- <r b u f- cm o U' <sj c\j
to so uj — <r cj u <r ui «'
c\jOs(Mr-<Tc^ir.ucvu'
B IO IO O CM IQ IO in CM
o sj cv -t b o <r n ^
CMMC 5. < UJ U? «t W -*3
PI <3 U M' IT MJ w
c\i on to in to u oi io u. u.
<tuu«rcnrif ip«i <r
u <t <r b <i ir ui to to Cm
tvusrt.r~oCMO!CM <r
M vc vr — uj U) u. vc vc
r-cD^(Vtr<r«-ir<T a
k> u. <r m to to cm so bj **.
CV<TU.sTCVOjs 7BB t-
r- to b a - so so so w c«i ¥ -
sr e; bj b in ^ tr> o- cv O'
cm <r so cj so c on ui u. »"
<r «r u o b B r- < tn m
U vC tf it u> U) ¥ r ►-> U,
ts h«r<rp P 1 c P ' i7> o
tv r u; ■%» t> u «* O' <c cr
tr n ij r j <r r- o B c*
p. srev'Vwou.J'U.insj -i
<S <i t> tuj & \ <r >r <? cm
f; o r" — «r u. u. — a u . t*
.?• X' a' u. v«
b «t it*. <r <r o — w> flv cm rj
•? to <z <r c . to m -r r. to oc
\ M< 'j t ^ <r u. k - \
f ^Q«r-«u -><fuvji
tv <T O n CT- <T 5 <T *0 <T
r k <r t. if c>. in u. u p,
B U -7 ^J<7C If) U. U t.
(V cv C. R CD S CM t^ <t CM X,
r. r tv
ts — O »<r -P B CT. (TJ —
r. b r> o cv — fjj — uj B
— '*• b u» tv o~ t- — in u, <7
1 ^ |f> t f <r tv — to «r <x B
— t? -r nif o p ^ n k t.
*S- -3 ♦QWr-lil'SC’X
b o u c» e u> -ij < <t a
<v e u<rPi k ppr u
r. r «■ ir 'T- «-p a' <r V
T B K* 5? *r! C U’ ^ f»J y V
&9Vb Sli^kP “T CV. U
B R- sr * e. sr o C'K-I,
B
> — Q
l» <A ui
/ — Q
&>
t— D-
ui h e>
o
T
CC ID O
E
UI
— <0C
a.
rr
b-JQ.
M, •
^ CD C\i
in — ^ b.
— p • <s
■v ~ - -ts
— ~ Z ^
• ^ _J
O u j H ffl
is e-
e» c. cw
ts (V
it cr cl> <£
in
h a cl Oo u;
=J ZD • ♦
tt. W 1/1 Cl D
DC<IOr D OOO"
w <U O COOU-OUQO.
ti II it 2 C H
hOXO^(3MS5.ce,S
CD « — CVJ K. <T
*->m CvLTCV(VtSOtSCS.CVtS
OJ CM <T in VC <T <r <7 <7 <T
tr <r
<r u
II II
X o
in vd
B B
*T <T
t- a. t-
X o II
UJ f— —*
Z W p
Pi IS IS
MT R
BBS,
«r <r cp
If, ? -7
o —« vn
U W w
• • l-
(t O' z
II II •—
•V tv II
X >- o
c B tr.
— cv to
IS c. tv
CC CD OJ
~ z t~
t- a. •
z = —
*-• z
II UJ li
W or. cr
fs C 6 -
<r m c
B B B
on 00 £71
H O X.
UJ 2 UJ
DC UJ 0-
BBC
— CV to
B B B
U’ <r cr t u u n- <r>
MiPGviPin^p
B c u <r o u c K m rr.c
B c: U C.' n. <7 r~ B <T U. t*J
U U7
x cr
<r Kj D If) Hi P P c B
PiP'cetreDPKP to <r
<X S U) U u.
u <r UP- cr <r
<rc'&-<r\<7'C'O.0'(r ? c <r> cr C7< c* cr>c o- a tr
iriohtt^<rciU'Ci'U.P - p k <7 in w p n cr
<7 v <mi <r <r «r c <r <i <r u ir d u u> ii' ru u it
s>
w
ts>
CVJ
B
<r
B
CV
in
cr>
cn
m
CVJ
CVJ
B
<T
Cm
CVJ
B B
to cn
CVJ cc
tU —
m ts b in
in t*- b b
<71 — OC
— CVJ CVJ —
IT in B B
to £7) in UJ
£7* C7N m D-
— — CJ —
B m B B
9 . to <r m
co £7i in r-
— — CVJ —<
Q io cjp- lOoBm — <rp <7Du.«7P'U.wrr<ir
OQU7«kPiWIMrs 77P7 ^ — P-t-CM —
PVD<7Q<I'-<I’IUJP'UStO<IDW»ODlfUn
^P-irUPiP’PKkKkSOk^UP 1 7k7
BUIiO(U«TR>ITBin -T U CM C\, io CVJ O’ IT — <TI0«T
KD<7k<f UI <7 S <r O e CVJCMlkJCMB£rir> BXB
--u-wQtiioMninicMnuuJcr. <tnowai-
(CStOKlli.kMTS'fi-JWUlDlOOlOf'P tOCMCM
B
in
CVi I
B B
CD £7.
*7 so
— B
in 6*.
r~ r-
<7 ST
U\ B
B r>
O '- CM
— CVI
B B
kj er.
r~ —
— cv
B t-»
to £71
f- —
— cv
in cr
so W
— B
— CM
u in
CM —
^ to
B ~-
B B
O' <7
<7 —
lOIOCM*- CMtOCM — WOtJP k C 5 IP 'O r„ umt
7001.0 00^0^1104)7 0, 0<TPKiP7
ir. ir
vc r
in b
OJ to
m in b
in. in a
in P. r-
C „ r ‘ e.
CMSTQUJB UJ C. £7 P- CM UJ «t < CM B U. U UMl k‘< 4 J
u. <t — to no B OJ B — O U. m CM CM B li^ B CV B B
K) UJ 7 ; <r S 7 IOi£)Ms(E<CEP-Q-U’-G<Jli J C
ui-j w u sr o id n — uj 10 r- v o Cw <r " b cm o
IP a\ P-IP Q U. ifl 10 P OS Os <T\ BIOS—- £7\-«ino —
VUP <7 U<rt-B-oop'ippr. ojkjiou
o tou.o<tx£c — p-ctcmo — oBcr — cvu m
ts. <7 < B to ST UJ B — <7 -- — Kj r & r O o Q (v, <r
B P SIP
to or to uj
Os IO B CM
ts> ;B —• ts:
b b m in m b
m — to or, 01 00
CM CM VC VO CV £»>
CV-— B B
B
in
to
B
r m b if
O'. CM B CD
— e. e. t
I 1 •
5) ip in ir
t- B CM —
to <7 p 1 r.
— — — CM
I ! • l
m ir> b tv
to sc B oc
— to <7 VC
if b e ir x m
— £7- — if £D CM
cm m —• on b pc
B C. B -- <v. —
in
tr.
B IT, in B
|o If • to r-
CM O' VC —
— Oi — o.
B B in B If
r, D- CM CM CM
— CV£7v< , ~
— tr cv — cv
I'll
B m B B B
r in —to os
B £7V m to «7I
— — — B B
If' u 1/
«r so C.
to cr p
B 1 CM B
m in m b m ir p . in e b b
<7 OjODP P P~ CM f; in K —
B or to to B — or to — inio
B — — BB — — B — OB
oj kj cr cm sTF.tsinu.BB oirno^s-in<7K,
CV V B C’ <7 ^ C ST - K IE « O o U If F. D «7 <7 1C
OD Q B CD O <tBU. UJ— BU-UimiOlf' — £7\<TCMO
UlU? ST U OB «TUJ — t«-B IS. <7-7 <1 C. OB^TO
c;. to — bcmb — <ru. — vrujiocvcMBin. «v o* o <7
U ST — B to ST — o CM B Uj fxJ C B U P' C> U Of ST
rcMOc — Bu>BBrou><r<ru-Cvn<rusT«.ifO
«ro ^ cvi cc. id c f. Mu - - < pj to <r src^^ u.
Vj o UI 10 O' d f ip OJ
to o C sr U B O' to <7
intO<T»OK. K sr «7 <7
<r <r <r <r sr <r <7 <7 <7
U—BtSB<a.sj-
— oj Q B b b b rr
sr * to ou m u> sj
srsr S7<7 ST VI ST <7
O — U. C C . <7 10 £M
tSP BBCT, UiO-crsr
in to iiipv si if m sr
S7S7<TS7<7S7<TS7S7
0<TUJBir «r CUB
tO Cs BB — U-BO«B
to k) to uj k, sr in if u'
<7 S7 ST ST <T *T <7 *T *T
If'CUCC
O O B B
to ro u u
S7 S7 ST S7
uj sr t^ ts
e B U B
U' if sr ir\
<T ST ST SJ-
cr to u
B B B B
u. in if in
<7 <7 s; s-
e — u. u*
U R U U
sr if si
ST ST ST ST
(V D B. 9 ST B Cw vf. U. <T D- lf\ B If CD U . <X <T a’ Pi
IS U F (J 7 FF UI 7 P <7 7 <7 n <7 <T <f k P fi P’
cm to — r ocr—truer, unto — toBK-sTKom
P 7P,7tCI5,PMS.'E6K klfFt. C». PK <7
Hi Uk - 7 IT7 7 ui U. If P t) 7 c - 7 7 r - u
UJ to B tO K" 77F-7UIISOPIUK IO 7 P’ O B
u. f- n — N K — V V> — O — <VI CL O B. — O f— UJ O
j ch r •-> < 0 13 . a. a. a. ? < o. cs c a >- uinnporih 7 x x < cr tt t-_jf-
R'U 7 -< 2 lD 000 CCCt- 0 <r<r-X Z f M If' Z Z O >- H h h « O ffH E
CflU. 1 -HMO.a. C.C-£Laif)hJJJO^«l-77l' il -slJnU)UJUit-p-h7<
oddc nncococ c c. o u u U u j jraanao. cr. tncntnu.
U' O tr U O n UJ C — — — ..—.. ” ” ....
C. WDUiO'OJirSUiDrOJtt'O-1 O' O' O' O O' O 9 O O' 9> 9 9 9 0. O' O' O O 990
C.0.02X3<rU'02I3«rUJC <L R - P. r 7 If VC P B.' f 7 III U f U’ I., K - P f, 7
/ 7 U- O I— I— J> P k Oh I* J 5> I io D t- io f' k. t> r t, io to n io r. io r; <i ^ ^ ^ ^
SSVVXVVfV^i-V-R V-VX-K
Page 28
84
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
U!
2
<T
©ft
DC
o
o
to
cr
u.
>-
s r-
Q
— UJ
ft- o
<r
o
CC _J
Q
o ac
<r <t
CC
H*U
CO O
<x cc
_JCX
. — — w
c *
D. CC
UHH I
>- war :
U! O, O- C
G Z 2 2 2
cr
S S (
is S I
V£ s t
2 • *
— C t I
J » 1
h K K •
=5 K >- >
• a. r t i
o x
• IS UJ
■ O z
lft t ■
ft -J — — i
>■ roc
C h- UJ O (
<i to cr
UJ — (St
cr j in — -
2 Z 2 z :
7~ I
u i k cc a a; i
a. a. a a a. i
s s K k k i
j «r ir in —-— •
=3 C
. in h
j o o
: ID id
• u
* UJ —
; cr. — to
u s u>
tO >- Pi
j ♦ t-
: cr is —
■ s <r X
s uj ^ _i
— j o _J
o cr <r
: o <i o
her n H
. o 2 UJ Cl O
'Ofcicr
IS. IS
S K a -is• —
- o «si cr. s is'
■ — cv cr — —
uj 4 ~
7 UJ-
— lft VC?
-J cv —
• r-~
Dt S —
<t X w
2 O' ~ -J
O' Q ID J
zd cr <r
H V <1 O
U1 U’ il ii
cr cr c© o
g 5i s
c cr IT. —
is cr is
— <7 IT lft
w
2
Q ft-
2 CV
CD —
O II
cr —
cc >-
=j —
to is
~ <r is in ir>
J 2 cr v ft ft- f~
| _j cr g — CCl C\i Cv, co cv
*T=> SO - — =J — IS
. o h r ii w ii n to ii ••
II Ii! W S O 5 *-0 5 ft-
c* it ir x c >c. >c ir >• x
a.
to <r <r
re <r
c if <r
II c\j
G-
2 X
<T - O
•V I—
a. ui <r g
r> n s - g s
«S l IS IS
f— >- ii Ki ui cr
2 U! •• I
— trio-stv'scacn
: — s :=> — vc? x ro r?
) " "" to h- V II ex Ii to to
. — — r o K UJ 5 o r, o o
' X >- X to IV i X U. X o o
«S is.
is ir-
>
S S
CV IS s
l is IS
m in cr.
i
<s ao cr.
>-=>=)
ii to to
<s o o
>- ID ID
IS IS
K IS IS '
4 is IS
MT. CM
II lO to
KOO
X ID o
Cm CXI
>- m
n to
•s o
>- ID
to X ex X
CWOU'
U 2 U 2
cr «
h- >-
to II
fr- —
IS o X
— 0—2
cu ts, rr
o x ZD
f— T H V-
O UJ — UJ
id cr x cr
& ts cr- ts cr s in s <r. u> r» r. ^ s <* c o
cj K' <r c rs — n cv k- <r <r in vr r o r* o
SSSCTSSSSSC SSSC CvG—c;.
tr in L'' in vC' vfi. vr vo vn vc* vc? vn vn vc: vn vc.
s s s s s s s r, e; ® g s e r. t s g k is e>
r — p ^ s ir io h cr <r rs — o r<rmv^r-<rs —
>. S s S S S S S S S S is S S s S S S CT| s s
r'-r'~r-r-r~r—f'-f'-r'-r-cc'cococx.O'.DjiX'Ocx.cTicri
OSj
O
o —
Cv,
l- »-*
fN
5-
Qu
r-
u — Ci
V (T X
CP" J
G Q
<7 0 7
< C
h- Cr
>-
G
<r
W
ft
UJ C
a. g — —
CD ZD • Z'
oh a c
-J — r- • T r
^ U t" * r C < -
w x <r c <r ir x f .
ft. h- > <7 4 — CT'
— • C\ *7 !• * —
r'G^ — c s <r s - — — — c
— — C x < 1 ' 4 «IC< • t C.CUJ. o •—
S'-o —"svvio • • • c. 'j n
^ J J I- H- <T *— CV f • h h - C t/ f \ c
O-J ; 3^ ? OR'tt 7 1''"
ft. <r >: •- a ii n •• h h a n « •• <r a r
<r o uj cr z <7 — c\ ► — cr z< — co f »• ii u 1
ii ii o t h « < < <i o. a h t x r " C5 ct
X
h S p S Cv s 15 s c. s s s s s s s t
itpgc -prsif'njhcr^K-KK-cG
»-. s; — 6. s s s tv p ssse — — —— s
i*’ t ; ~
o *-*
r«- o i r
U’ • *
f- !»',
to <r <r
o g 'r
h- • • ^ —
f- »- «7 U
t W W VC V»' c
to 2 • • S
CT
S
K
ii o m x >- p vr> O'-'
U t** IT b- ^ ^ *- L f ^ _J 2
h- • • • • t— H eti (V U J J ^
— — 4 4 z 2 r* l- ft • 4 e. < r>
u <x <. x x •— •— tv x o ci o <i o h •
c ii ii •• •• ii ii o u* i— ii ii ii ii tu
U >- > x >• g u cr 2 to g g x 2 ) a.
s r. s s s c e s r r ts s s s s
^ c x<7ir vnr-crrrs—c\K<r
SC- SSP. SPSS — sssss
r ft ft’ ft cv ft ftj ft. cv ft ft ft- r- ft- r-
co
U’
to
<r
7.
K)
to
o
2
o
s cc s
4 . <r *
s x e.
— k> —
ft- ft-:
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
) •
J
85
DAZZLER DRIVER
Subroutines and a'Chase'
BY PHILLIP SIMPSON
1043 Shandwick Ct.
San Jose, CA 95136
Dear Jim and Tom: Received: 78 Jan 6
After reading Joe Sanger’s article Video Chase for the
8080/VDM (DDJ, May 1977), I began to wonder why all the
software for video display devices is being written for VDM’s
while I sit with my $200+ DAZZLER watching random color
patterns. What happened to all those people who bought
DAZZLER’s? Why aren’t they writing software for the rest
of us?
The solution was, of course, obvious... the reason I spent
all that money on this funny looking box with the blinking
lights was for the fun!? of programming. So I undertook to
convert CHASE for the DAZZLER. This accomplished, I
broke out the subroutines used to drive the DAZZLER, added
a few more bells and whistles and created a DAZZLER
DRIVER. What follows is a description of the driver and my
adaptation of CHASE! I’ve also included some examples to
show how it can be used for display of moving objects and
alphanumerics. It can even be used by a BASIC program.
One other note for those people who, like me, have a com¬
puter without a front panel. If your DAZZLER mysteriously
turns off from time to time, check to see if you have imple¬
mented the power on clear line. In my case, the line was
floating and random noise would turn off my display about
every ten seconds. This can be fixed by putting a pullup
resistor on pin 13 if IC 58. A simple solution but it took me
almost twenty hours of trouble shooting to figure it out!
Keep up the good work!
Phillip Simpson 1043 Shandwick Ct.
San Jose, CA 95136
DAZZLER DRIVER
The DAZZLER DRIVER subroutines form the basis for
a comprehensive display driver for the DAZZLER video
boards. The DAZZLER itself has been described in other pub¬
lications {Byte, June ’76, Popular Electronics, Feb. ’76)
so I won’t go into any detail here. Below is a description of
each subroutine, not necessarily in order:
TRANS-Urn 1200
This is the core of the driver package. It translates the X
and Y coordinates into a memory address. It assumes the
picture is in the 64 by 64 resolution mode. If the X and Y
location is in the left half of the byte, the carry bit is set.
This is a modification of a program that originally appeared
in the December 1976 issue of Byte. In my version, X=0,
Y=0 is in the lower left corner of the screen.
ERASE’—Line 7620
This routine will erase 256 bytes times the number in
the A register starting at the memory location in H and L.
CLEAR- Line 7700
This clears 2K of memory starting at the location contained
at ‘MEM’ (line 0222). All routines make reference to ‘MEM’
for the starting location of the picture. To move the picture
to a different area of memory, just change the value stored
at ‘MEM’. Remember, it’s least significant byte first then
most significant byte.
PLOTB-Une 8040
This routine will plot one element on a 128 by 128 grid.
X and Y are in B and C respectively. If the carry bit is set,
a white element is plotted. If the carry is reset, a black element
is plotted. My original version of this used bit rotation to get
to the right bit within the eight bit byte. However, after seeing
Lichen Wang’s solution to this problem ( DDJ , Vol. 2, No. 8),
I adopted his method.
PLOTG- Line 8300
This is used in the 128 by 128 mode. It will plot a figure of
size D by E on the screen with the lower left corner at the X
and Y location in B and C respectively. The location of the
figure to be plotted must be in H and L. The following
example plots a flying saucer on the screen, then moves it
from left to right. When it disappears off the right side it
reappears on the left. Note that the figure of the flying saucer
has black elements on the left edge (The routine plots X, Y; X,
Y+l; X, Y+2. ...X, Y+n; X+l, Y; X+l, Y+l.... X+l, Y+n;
etc.). This way it erases itself as it moves across the screen to
the right.
7039
9618
* FLYING SAUCER
7030
8815
*
7038
C01978
0100
CALL CLEAR
7033
->E7F
0105
HVI a7FK
7035
B38F
0110
OUT 6FH
7037
816060
1080
LXI B/ 6868H
703A
11088E
1685
LX I Dr 6EG8H
7C8D
211D7C-
1010
LXI Hr LQC
7C18
E5
1011
LOUP PUSH H
TCii
05
1012
PUSH D
7C12
C5
1013
PUSH B
7C13
CD1F78
1015
CALL PLOTG
7C16
Cl
1616
POP B
7C17
Oi
1617
POP B
7C1S
El
1818
POP H
7C19
64
1626
I HR B
TClfi
C3187C
1621
JMP LOOP
7C1D
86
1823
LGC DB 83H
7C1E
0008
1824
DU 6836H
7C20
fffiin
1825
DU 1C88H
7C22
I43C
1026
DU 3C14H
7C24
3WC
1827
DU 3C36H
7C26
141C
1028
DU !Ci4H
7028
6808
1629
DU 0S08H
TCZfl
0600
1030
DU 8000H
7819
9808
CLEAR EQU 7819H
731F
9810 PLOTG EQU 781FH
Page 30 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 22
86
Figure 1 shows how the individual bits are plotted.
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
EIT 5
BIT 6
BIT 7
00 00 06 08 1C 14 3C 36 3C 14 IC 06 08 00 00
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
the game ‘board’ is 32 by 32. Each square is made up of four
nybbles. For example, to put an ‘X’ at location 5, 5 load 5
into both the B and C registers, 96 hex into D, 69 hex into E,
then call PLOT.
GET—Line 7210
Get returns the value of the two bytes at the ‘board’
location in B and C. It is used by the COMP routine to see if
the location contains a man, robot, or fence.
COMP-Line 7505
This tests for the presence of a figure at the X and Y ‘board’
location in B and C. The zero is set if the figure in D and E
matches that at location B and C.
Access From A BASIC Program
HEX DATA
Data is plotted most significant bit first. Grid can be any X and Y
dimension but 8 bits high makes it easy.
FIGURE 1
PLTBY—lAne 8835
This plots the nybble in register D (the four least significant
bits) and the X and Y location in B and C. X and Y should be
between 0 and 63. As with all of the routines, if the values
exceed the limits the more significant bits are discarded. For
example, 96 would be truncated to 32.
PLOTW—Line 8545
This is similar to PLOTG except that it plots one nybble at
a time. Although it was designed to be used in the 64 by 64
mode, it can be used in the 128 by 128 resolution mode. X
and Y must still be less than 64 but the display will be a series
of dots depending upon whether or not a bit is set. The
following example plots the letter ‘A’ on the screen using
PLOTW and the 128 by 128 mode.
7C00
0018
+ PRINT AN "A"
7C00
8815
*
7C88
CD1978
8100
CALL CLEAR
7033
-3E7F
8105
MV I A/7FH
7035
D38F
0110
OUT 0FH
7037
011D1D
1800
LX I B/1D1DH
703A
118403
1885
LXI D/0364H
703D
21167C
1810
LX I H/LOC
7C10
CD2578
1815
CALL PLOTW
7C13
C38966
1821
JMP 8
7C16
1758
1824
LOC DU 5317H
7C18
0389
1025
DU 0903H
7C1A
1558
1826
DU 5015H
7819
9880
CLEAR EQU 7819H
7o25
9818
PLOTW EQU 7325H
Gf 77V—Line 6035
In many games, it is necessary to see what is in a location
on the board to see what action to take next. GETN returns
the value of the nybble at location X and Y specified by B and
C. The value is returned in the four least significant bits of the
A register.
PLOT -Line 7003
This is the first of three routines devised for the game of
CHASE! Although the DAZZLER is in the 128 by 128 mode,
In order to access the routines from a BASIC program, first
POKE the values needed for the various registers in the
locations provided (lines 0200 to 0215). Then CALL the
appropriate routine.
BGETN -Line 2125
This will get the nybble addressed by the X and Y bytes
POKED into location BC and put it in location ACM.
BPLTN-U ne 2310
The nybbles stored in the least significant bits at DE are
plotted at the X and Y location stored at BC.
BPLTB—Line 2310
The low order bit of the byte stored at ACM is plotted
onto the screen at the X and Y location stored at BC. This is
intended for use in the 128 by 128 mode.
Here is an example of a program that takes the X and Y
values and the color (Z) and plots it using the DAZZLER.
LIST
19 REM BfiSIC PROGRAM TO PLOT COLORS
20 REM IN 64 BY 64 MODE. Z IS COLOR.
30 REM Z IS IN THE RANGE 8 TO 15.
46 REN
108 COLL 38745
105 OUT 15, 48
288 INPUT "X=";X
205 INPUT "V=";Y
218 INPUT "Z= H ; Z
309 POKE 38721/ X
305 POKE 38728/V
318 POKE 38722/ Z
315 CALL 38766
400 GOTO 288
READY
CHASE!
The rules are the same as in Sanger’s version. However,
scoring and comments are output to a teletype or TV Type¬
writer rather than displayed on the screen. Also, there is no
compass rose displayed so you must remember the moves:
T YU
GH J
BNM
where H means no move.
User supplied routines are:
MONITOR
Puts the address of your monitor at 7CCEH. This is where it
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 31
87
iXIO
> ^ *» "l
! '3D OD 03
• O O O -J *
’dd a! 2d
i «3D IT> CO
> UD MD r-
»r -.i i-.'i fs->
LO 'oD .3? LO •
r- r- rx> co *
r -> ixi r<i rx* i
i5co_j:
: C£o>:
: uj co cd ,
• 32 ccsr :
o
» CO LOCO I
i CSC* CO xH ■
i
ggg
I- 1.0 C3i l
XUJLOi
[y zs. Co
21—«UV
t— UJ *
UJ 2D O «,
IDO'
i— c*c cc i
• *S> CO lO
I CM CO ‘3D
■ '** '3D co
• xH CM ifvj
CO LO 'S* ______ _ ______ r ___
•h ■h c\i c>j iX« fa fa fa ud '-jd r- c5 co co xH t-h cm cm r<i fa ^ fa fa gd
CO £D CO CD CO CD CD '31' CD 'S' S' CO CO CD CD xH xH xH xH xH x-| -xH xH < x-l xH xH xH CM
c\j <Sj <Sj >:\i c\i c>j cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm cm
SI is *
h— O ill I— h-
j CftfiM \j\
li£!£R32 j£l
< UJ UJ
IUJGQ, >0 23
JZUJEUJ^
) x ^ X X ZSL
>— UJ !— H- f—
J 33u— UJ UJ
ZOZIhLL CD
- Ce.‘ UJ K— CC CD ClD
*■ *• fr # •* ■* *•
i IO CO LO CO LO CO ‘3D
) IO UD UD r - r- ClD ‘3D
_ co o it
X O Q d UJ
_i££owE
•3> ID '3 LO X LO X IT) X' 'S' l
•r\j od r- 'i r -i *#■ u*i id '.£' CC' <
co
r-
. <f X'
j r-- cti r- r-- r-. r-- d r_i hb
IrTNQS'QHQ-HUJ
8$teC3i£3
'3 ij,. 'O
. UI
! I U_ UJ
• o Ct
c3,jcc:
•-0 x o *:
' 'X x o£
1 1 — _ 1 x
CCiXtiJ 2 - XXCCXCj COXCC^-XcXil
1 £ 2? ~i £ Fb p 'i ^ S uj uj c£ co § i*\j 5'
! >"• H~ * C2! 3
uj u_ o co or *—• >- :> *—1 ct: cti z^- *—* z>- 11—1 :
33 —* »~h z e: 2 o q -c n a: z q co Ci sr n <
11 — 23 o_ <:c u a: s: 23 rc ^ ^ e i.n k: .x: *x •->:
Cxi ,cr i
J»L J|i. f Q.;
‘3>3>*~»Z>
) O O CO o
: a: ■&. ui b:
1 £ CO
• COO ^•
l OCl£ O
: tea x
LO CO S'
'Ti • Ti ‘3D
cr» a-. C2*
CO CO xH
U .»'S* U"!* «Si -3D U"i r>- 'S' IO 'S' b~ .S' U“> 'S> U" 'S' IO »3D U“« (
c\t 1 X 1 ix* rf .S' -3D co th r<* ^ cf to u*> 'ai* ••i!' r«- r- co od •:
•-uj 'S' 'S' S' CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM <
x-l xH x-l -cH «H rH xH xH tH xH xH xH
• CO LO CO LO
» CO CO x—I xH
1 fa (■<1 r-*> ro
•S' ‘S' 10
cm ro r-D
rv> 1 x 1
xHx-l H
gj-o X
03 CU
•C w ON
1-. rn
CT3 - X
OX ^
ui- U 'ji.' :^i 1 \l IJ*I
5 ™
D-INpH
, S r
» hk
) u
V N _
m o
C/3
5^13
fad's
oa w
r~-
'§0
uj r-~
| §
# * * -v #
*
I * X
CO * UJ
x i.n * ce; o
a= * r- ce; 1 j]
arr i t: ass
_ 13 ^ xlD
NO * C.J CO X
r-j ce. *■ 's. o oc o
X * CM I— OQL
id * -rH UT U. U_
*
X
§
OOQQ ©
2233 Z
Ci UJ ft ujO> 3 : ZZijj
X I— Cl. Cl XI— I— XI— X 1— 1— h-
§ t-£uS§Sdo!§a!£yS^&
o
r-- CLa.LL.LLiiixci.CLa.ij.Q,Q.a.LL
eesessseeeSees
"~vr o O O O O O ►*) *"^1 o
S3 S3
ouju uj
iSoiif* S3 *
CO CO CO 'Xj 'X' CO 'J’i Ci X Cl CO CO CO X
r- r- r-r- r- r- r- r- r- r- r- r- r- r-_
O '3 S' X' X> rt r-H !'•■) tH CSS UJ UJ IN. CO T-- U. X T -- C
llll I 3 §nS&§ 8 §S§ 8 B 8
X* X 1 X> X> dx> X x
Page 32
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
88
LTl
O'l
X X o
az<£ coc£
xx: as: x _ cS e
.. *. oo i” *1 co r~ ^
O UJ Q30UXUJ x X CO
_ x x x x
X_>X-J>-Di-x:>I»-C0XCL.>-Q£:0-:> CO X X Is- Cl. t—
-~-■—■ ~d x o o :z o o x> x o cd o x
— — * cx e: o. o i5L e ci- c«c
Q£ O X O CD X O CD X CL. c_> r_j .
KJCttEECtEECcOlXE'
vll
x + h-
cri i— ;i- >~i
UJ2WZ ,2h-
X >—I 13 H x >-1 7r-
'X Lfl CO LjJ
a. co uj co :c x
SuJ uj x o t— x
oi i— i— >- io etc cd
CD Z- Ci- !— X X X
X X X X X r-j ►-< X
X X
EC X C3 X O X I— X
oiujiot-ixti;
Oh-Cth J«H 1.0 x
X rH X
h* Cl.
X l-U X X CD X
iflOO % CD o
p aatfooi x cl.
CO.
is- x ru is- x. -H i—
-* i —i L4--*■ uu. i -j i_u. c-i r—
CL. C? r X O Q j; :■£ o S-= Cl. uJ
1 C Cl o ll £ O sc OIC cc:
o
CD
I—I
CC h-
O 4;- r~
I— Cb te .
LD h- .J
LU CM U !
y
»—<> LU U*l
i— to lu :c
id *x t—
o cc: !—
cc: lu cu x
*• ■*■
U") CD LD CD ID ‘xl 1 ID CD li .* X* LD CD LD X* (\> LD CD LD '3D LD CD *3? tH Tt* LD CD LTt* *3? uD 'Cx* LD X* LD LD 'ID* uD X' LD CD LD CD UD T *- X tH l-d *. u T -— i'j"i 0 'i
CM 1*0 M rt in LD L0 LD r- CO CO ON ers OS CD CD* t-) -kH CM CD CD CD CD r-1 x-l CM CM IV* CD ^ *!D T-i r-J CM CM I -*;. r<* vf- Tf v*- u -, ,x» d* .'d
CM £M CM CM CM CM CM CM CM CM CM CM CM CM CM CM T O CO CD O') I*'-') <*• *** •'*' Tt* ^ ^ uD UD IT!' l*D L“i LD LD LO LO L"!' L"!* LO '-O* ' 0* lD '-Oi >. 4:1
r- r- r- r- r- r— r- r-~ r- r- r- r- r^. r- r - r ^ r— r*- r- r*~ r- r- r- r-- r- r- r>- r— r— r— r - r- r- r- r - r- r- r- r- r- r - r- r- r- rt. rt. rt. rD. r^L rZ rtl
co
r-
rt
CO
r-
CO
r-
co
: ■UJ
UD u? X r-H JO X ^ ?'< X X CT-I
O Ci CD r _i X lO CD rL Cli O r_i
X
CD
1.0
U1 X
x-i X
ro .j
x
o Ck: lu
z lu
XXX
d* o
X* —I C J
uD CD' LD r- x
IT.' LD LD tO
O? CO CO
Cli Co 'jT' 'jZi 'j5
feu
t.l'l
S O x
= fel/l3
1=1 X !.J*I H-
uariuo
21 1— x •—•
uo
X CD XX f
-. X ’
co
X
x x
ElOIO % . .... X F- .. X i~
XX XX XX X X X X X LlI X X X X
— XX
Slxxxx -—. — —
x u'i co co x>x»x>>iiixa.ii>ci£iiw>Xii>CLCu—
t— XXXXCtiOXCDCDXCDOXXCDOO-:OXXXOXOX>X
OXXXX>CXXXXXXXXXXXXi-‘XCl.XXXKXXX
I
y
21 CD
_ m
SXc0rHLLii=
1 LU -kT fe l* 4 * 1
l— |— O If- L2 *— 4
LU I*“ •—* %
x x i— x x x x
X X
F- LLl UOOK=(««
X X O X X X
CD I— —IX X X DC X
XXX
^ XX
_I U 1 U’I
ID ID
Cl. Cl.
, CC» CO Oh
'si.1 'sO to to
>x*
r-
co
K3sOlS2a:P2Li^K:!>!*«!i3SagR!SEl2K8SKc3aa
X
r-
88
rlUrlrl'HrlrlUrl'H f.J UD X C- uj CTi X X 'X X X X O xH 'X UD LO r - CO X. X X X X X -H C\l I'D i'O r-'i lO f 0 TO fO M TO M CO CO X t-.
gglggglggggggggggggggggggggggggBSgggggggggggggggggN
X
XXX X H-
X ^ -X -X
MOOOiL
X
_I :>■ Z> X L> CL,
X £? X X O X
X X X X X ■->
I— I— I— X
i—* X
Xl X O o CO
H- t— •—i CiJ
QtCZt-rl
XX >~ I X *
a.r -
x
!5
£
a = -iL
X Xii£
X
X>>IXCL
U*l
H-
&xSe5
S
X
I
—. -- _J > X X X X X> |~« I—
x&xoxxxxxxx
_i M 3, t > »—■ rr- tk rv\ ck~ q «v
UJ X
uvZ2
UlO^” X .
X ** 2T fe X f-
* ‘ ►-* O c<i LU
_ CJ h~ CD
5 2 : fe fe «? e~ " ^ w
Cl. hh L— wm __h* C li
I— CO CO UJ x-l
HlUQir tl~
O i— *— CO CD LU CD D- U*i
_I > Z O LU X Ul -.ID
Ci. CO *-• -J CxL »— C*L' >C HI
CC*
r w
CO X
x r-
•ru to
X Oi
r- r-
ril Q iXl
ci CD CO
^ ^ ^ Xi fe L 1 *
a* co co
r- r- r-
C0 Ll) ll.
CD r*0 Cn CD
ftgoLuNr-N r-- r-
^inOr-C^iCDCDCDCDUJLJ
r-r- (ccoulcd re*ro roro r-oooror-o^o r-co rod*u.u_' ul. u. u_ ll. u.Lo cm cd : j^ r - d io cjcj lucd tHxH x-i ^ tHxH ,h h
^&5&se5E5E5gSSS^SSSS88SSSSSS88S88SS8e8p3$SSSS8SSS8388pS8SPS85pS9SSSS8SS
r~ r-- fv- r- n r- r- r- r- r~ r- r- r- nnN-P- r- r- r- r~ r-r~ r- r- r- r- r- r- r- r- r- r- r-- r-- r~ r- r~ r- jc_ r- p- N- r- r-- r-- r-- r-- r-- r-- r~
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 33
89
—* uJ CtL CE O rH
cci —* o ►— o ►-* hr k — Or
3 Si 8 coco Sob 8 s! 8 8
Ci CO _J Q U-IODII
aociuixju Ci
JxjuiJ^|,nj^j ! xa, ; jac..gce;ci,La.Q;
Cl. i-i CeC
QO CO CC CCE CO ©OS
CCiqm i-h p to *. 1 —i _I
ci __hl u-ujci -jaru-x ui
Ci l.il
iii cq >-1 iccc
:c -i: o a; P- iu
| — 1 -l 1—4 ?JJ ' >'
UUJ —MX —IUIJ.X >11 —I IL XUliJ —IXXi UJ '_'
Cl CO Cl X _l X X _l X —I Ci'XCi XOX X Cl CM C'iJ X _J
cijuiJWliiJWJiQ.Jft: Jcco.a.a.^ in c>x crixxo xac i— c>xr-c_i — 1 ~ cl
xo iDipbEoSooxoNXzEoooNXIrzDxSji-o r-j ujjohxi uj u'i © us
US DC I.i'l X c_i X X O CL r_i X Cl_1 Ci *“> US *—* X X O Cxi X U'I •—' Cl ■“> IX CO Ci O CfiXX U'I >—■ Cn XCCOOQ X
_l I-
© X I— Ci O
Ci i—i
► —I i*y i *H
CmC CD »—«
X _l X *
c i— .
hi >—* x x x P>
I— co p <*; C.i
o i1 j £s x c
CD J« V-
Cl uj X
uj i u x r-j x
x cic x <<■ •—i _j
i— :o i- x ui
O CO XI
JWI- 2 U.O
CL X X •—1 CO X
s> S' in © uo S' uo S' in s> uo © dd © u-s © dd s> in © in © m © uo x s* in © uo s> in s> in s* in © uo s> in © in us r — © un © iio s> do s«
o:> sis> x x c\j cm r^i f <i ititiraouwx x co co j> as © siriHri cm cm r-sos rt- t do uo ms us r- x co co as as asas co © x x c-j cuos
Cxi I'OCO I'll CO CO CO CO CO CO CO Co CO CO CO C-J CO CO CO CJ c? 't'lt '»• If t)- «J- vf Tt ij- 4l- <1- <J- Tj- 'C If «t 'C O- -X -J- O- *f«t DO DO DO DO DO DO DO
u.iCOlOCOCuCOCl'lDlCOiiOOic6COOCiiuCliOjCuCOOJtOCOCCiCOOjCDCl1 CO COUCOCOCOii CO CO S' CO CO CO CO COCO CO CO X Si CO CO 'CO
OS CO
X X
CTi CTi CTi
r- x x
CTi CTi CTi CTi CTi
x x x r- x
§ £31B 8 8 8 § 2 § £ 3 ^ 118 § pi zd ft 8 2I $ 8 81 & 13 8 7J j§ £ 8 ft1 § 8
■ itmq n >:
«£= _j _ j Q'
: cj «x en cn sz:
> or* oj re ■«*- u“ r
i xH tH tH xH rH 1
I x-i xH xH xH »H ’
' 0C» CO CO CO CO <
narix
■ >—* I> Is- l—l ?
IZOOZi
: x S x x'
' 'ii* IT!' CSi U“ •:
i r <» i s -o xf xf i
• <X» CO CC« CO CO
b'efxpec =u3 e a
«.« X :> > x 8 X X > X X ® «’ H C " J 8
!§££S2&&ggg££3ggg88S8g
I lU 1,1 I
88 ,^o
x O uj ui x
X. X X
jS t G 5 3*: X .8
--- uj m xxx
XX . P X
U'I U'I Ci Cl CO
-J CD S *
O Ci^ LU O CO
■^LuLU-^U. O UJC'iJ
1X1OZC1O JCOtH
#*■«•■«■*****
:T. Cl,
r- r-
:X« *JD U.
LL. U-. iJO T : Jjkt J II.
r- 't <S' cd 'S* u.
EJK:^£3&S!n§S^£aeaiiFea!2Syj®u!s^eJWS^KHiEaieSfcS8S8}3?938?S
! Xl' -■■■-
X uli X S X rx s£ ^
>—H
UJ > *-h :••<: cl. ' Cl.
u'i o >*}— sr :*c r-j :> 3 c
.X sr si :< •— o cc: si *">
Cic: uj
lli ic: -
■:*. ^ cc
cc o
UJ 21 CD CU* U'I —I Q_ I> CJ Ct: V- 1—
—I :.Ll 21 lC J > CC Q CD I— X “> I O
CJ 2: *—• UJ CL S= CJ Q. 2£ U'I 0£0«
-J
# * # * * CJ ■■
a X
UI
O r_c
dx"tS
O X :>C O Zr-
>— 1 '-.. cc;
1 — cc. x co cc;
1 —• rn 1 - c5 rp
co 1 -. c i
CO 3 .
X C'J O 12
•H UC i<i i-i
X * !X CO
O CO !— i—
x C'j s; 2: i—
x x x ►—1 Oi
i3 x
X CiClCD C'J -.
x
o xx x;>-
XXXi X XXCTlfiZjig
Cl ^ i tL C'J -. -. '-Cl X .<
co X r-'i pi x lu
> Cc; x x
x X' x X o x s o S' ci: x goal x
xclu-O-Xecciee u; x > i£ x x O *-•
O'
co :=- >• x x
X >—I l-H UJ 1|J
o c .1 o o ce:
S' D*| S' DC' D“i S U-) CO D“.' S' X C'J C O 'J- DC' S' U'i *3D DC' © DO © D“' © in © IT' CC' DC' © ID © uC> CD DD P- © C'J ui © u"> CD D i © li i r- CD U jN- © C'J
CM C'J C-J 10 r t uD uD ' O \0 cri CTi CTi 'Ji CTi CTi © © X X CM CM C O C-0 Tp ij- © © X X CD CD X f -0 X- CT rf in ID DC' ■ l' ' O r - f - CO CO CO CTi CTi® © ©
us 'x P lo 'X lo ui us x x x x x x x r - r ~ r~ r-- r- r- r- r- r ~ r ~ cr-i os ct-i CTi •:» © © © © © © © © CD CD cd cd © © © © © © © x x
r-~ r~ x r- x x r~ x r- x x x x x x x x x x x x x x x x x x x co co co co © co co co co co os co co co os os os co os co co os
co
j\,
CD CD -Jj b“
CSl Cu! S' Ll.
'll* cc uli r-:» re gc «:g «2i ? e
x in co cm x p p i'-o O
vy L4- Uk.. ^
12!£G 6
Page 34
90
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
csi co x> re Oi r- x o ® <ti co r- x c. rr r-- cj x co x in <o re bo o h tH co on x co -h co x ce. r--- c* «-h s> ijj h co cj u _ .< cr-i o m a-.
'S> r- u_ o r-~ r- co th c o is r-- tM co n- co in **• c o o 'S' X Lft 'S> r - uj in uj s> r- 0 co s uj s> ro o ® r- co c r- cs? co o o r- ® uj r-
s> xh re an r- ro no co 'x> u. in r- co t a-, co ■*- an uj co le x c-o c-o be u. u uj h h re cc co cc co co x co be uj x op, -S' be rr, co an co re
s> cc o is rr uuir--ujinu.o co -e- o r- *r r- r- uj uj -a- r- cj o -*t gd ioooh co r- co uj in r- uj co re *r o co uj r-- cc r- o co
'S> re co uj re oo x in as rr r- r- s> 05 co co co uj co r- be is *h co or r-- co -h co co re co s> cr-i u_ x ',0 an rr an co co s> an or cc co 10 re
co o r»- 'S> o is C O -e- r-- dr rr co u_ r-- r-- 'S> r •- co r- 'S> o Cj is is -h or Ci p- co co r-- u. o -h -a uj is © r- ixoo- is co co cc co o
co co x-t re cc mmr- '-o u. r-- co co co cc re -r r- o> an rH o- cj cm h co m cm co 10 * uj co u. u. u. co re u_ r- co co es -<H co -«h ue
>S' r— uj o r- co r- 0 *r o siqujiciq re s o fo sj rs r- o re s> r- o r- o rs <s> u. o o r- re co rr uj -e- u. r» co cc cj o co uj o
si rr re 00 co re co cd co co co <nn cj *x co o a: u. *o p- 05 n. co o <c n. o- o 00 co re co re i/e co an -h o ac uj -*h 0- co be *-i ai «-* •**
S' re o ft ,35 o rs 'Sj co r-t ft rC co re -4 co s> & s> »r r- ucoo-r- re o r- re uqo o uj r- s> r- s, re co s> co <j cu r- o co
co re co uj re co re co co co u_ r— co an co x r :c co S* r— cc r — o- o Jn n o- o o uj cc «i w u. ui u. <h co u. i-j ern *0 co co ue an co an an
Q on ilcJ rt.vF o- fZ o r- rr ft r- C ‘ s> co -h re ino re o ci 101;-' c re -h u- v-i c? n to u. r- cc co lu o r- r- r- r-
si S' re re an u. re co co r e o 1 i_ «r u. co co u* co cci be co o in r co cu in m co s> co u"' r-- be an co r-- re s> ir> co s> an an uj cc re co
0 r- o o r-.c 3 oN.rn- in co s co u. co r -d 0 r- r- uj r - tS cb. uj r- o c. o o S re uj re cj r- r- in s> -e- Qj rH r- r - co o W cc
S'
S'
CO
8S£3KD?J3l5^ygatS2!(a88e3?SSWQifclQa£Jifcl3«SffiSS8eSR
r- xr r-- *jd
r o cd uj
&£3Kiaia3;3a£38i
co S' &:> S' co S' o? co
CO
Cl.
f “1
ro Sj
:c‘ co,
01 Cl
'SZ i.i'i Ui U'l
cl 'e o n Cj
0
co <
co Ctcl l i_
cc; cd >-
'bD -J co ^
UJ
-JUJ
iO
u!i >—
~ r > ;— o
r-. -X *—
I— UJ r-
u: o or
c!« h- ;.j
O i .r> C-' •;
uj ~J -•>;
•. 1 * 11 — cc: Ci!»
»•—4 C3
:n _j -z -■<' IE
Cl. < D*C *—'
yxui'i cjs
cc :£ .. . ij_ .. co o i—
uj cc o3 Sj
x Ca X X _i
o d 2 : f
> >—1 !> '-'"I U*l. J Cl
X X'
^ S' 1 £|£ r'i
i»4*w *s • i— . L %
j -.a CC S' r- cc
-J
>x x :c '
IL.
cu crl CD cd ;
: cc:
. U» I L.
I - J Cl. * u_ O r — 1 CD -> " ■ H '-C > i l. Cl. I—
ci' <x o o o x fc* ^1 .^1 .j ~j cp: o o i.u
cl. o x *-> x x SE; cn lc; cc: S ii cc c 5 x cu c 2
.j
Cl.
Ll.
UJ
..J
C»C
:c
I—
x :c
UJ LU
CJ
r-j r-j
xx
* * CawE 1
•3D b"' *2D l/"' X' CD 0"' X* lO O LO 0 |j"i X* u“* r ~ CO CD , .’ -J lO X* bD X* UD CD b“.‘ X* u“* X' lO X' uD *2D C‘*J ( •'.* OD X' OD Ll“
[■— ['■- CO Oj X X' CD rH tH •' •] C>j O') , i r>/- xf ■’•J 1 u“» u“« 10 L“» •! O ‘.O T C-- X* X* H C -J C - *J C-O ' D r J~ 'J' T T lO OS iji X X
Ct r .T Ct ‘--r Ct co co co co v'J CC' o? co co co co co co co •:«:» co co co co co co cr*. rri cr* cr . cr* cr* >y* cr* cr* cr , cr-. a-, or-, or*, cr-. x x
'-O '-O sO uO Cl* Cw COCO u? X* CO CO Oj CO CC* CC* CO CC* CO CC* CC* OD <X> CO CO CO CO CO CO CO OD CO CO CO CO CO CO CO CO CTt CT»
cr-.
'.L 1
r-
•f
•;c
r-
X
■•H
:c
r-
CD f •'*
w.
•~J '^u.' J-.H LL. '.-'J
l:~i x x ‘-l' r - l • U~» lE. >-H x bu o. o X. r- r-- r - r-- r-~ l^j •.»:» rxi r- r-H tH a-.
:.U J i •- LlJ u“i O lIj L' CEi L-i : - :lI O N- X X« X X ID r-- LlI X T-- O UJ O
r -cg
0*1 ^
k—< *.£»
CD rr
LU rr
CO LO
*r -*r -*r Ct_
S
_j
> si Cu
I'Ll i—• b-
Cr: S' U. -J
ca ^rccaujcsniCL
:c :c :c x „i
X CO
L‘l
2 UJ
'X
u. x S'
CO- -
cr
ca:
U j i i' b ’ui o uj
,^i
:oiy.o
1 d cc d So ■£
XX
cbcSx
:i- x
CO LL.
lX Ll.
ao
ll) x x :c
, J X . J ►-' I.I'I I.I'I I.I'I ..j I.I'I . j n. Ci-IX 7 j X Cl C> >— 1 X O '''—_I -i- C> , X ;> ,-_n r_n rj O —' C=- K - J — 1 1 — Cl Cl X
X ox c=- X' x x x x xC' o x or-j S 2 Soo.NCip>uixoo 2 w&b;a 2 $zQSi>[ijC' 0 o ro
i.i'i x cTi x x x x S' x S' ll ci—iS | ->i?i>-"e£uS_U lEtx-jilJlcx '.n 2 x x x x x j£ i—".n x x x x £■ x
CCJ
X^i .
X
XiCJ
X '.n —
Z 3 .
V-
r-j
cu
.0
CO
.0
•X
U“ LO 'j!' LO X* lO -D C**J U“* *D u“* CD u“ OD L .* '7x' u"« vx* UD u“> X* C>J lO *D uD *D L~* CD u .* -3D cO CD U“» CD U“* '^D uD CD UD -HD u*.» 02* C\l U" *3D lO <:£*
r o r f lo to * 0 *.o • l!' r- r - co co cri cr*» *;d x* hhoj c -j ro ro ro -rr 10 lo • £• ll* r- r^. co co cr-. cr* 00 h-h c-»j c- j ro co Fo rf ij“»
L.D b“j U~J UD LO UD lO IT) U“.» U“» UD L.D LO u“. lO ' O '-O •.£. lO ' O '-il* *-0 ‘U' lO '-O -aD '-U LO ’ O *-D lO ' O '^l* 'aD v»D ‘-O T— i s — f — l N — T— i's_ r-— r— P— T — P-~ r—
•X» CO CO *rO 'X* OD CO 'X* CO *X* 'X' CO CC* CO CO CO 'X* Oj CO Oj CO Cu CO CO CO CO CO CO CC* Cl* CO CC* CC* CO CO *X» CO CO CO ‘X* 'X* CO CC* OD CC* 'X* CO CO
L0 CD LO
to u:* 'L*
r- r - r -
OD 'X* *X«
cr-»
IL
CTl
CU ©
cri
a:
cr , a-,
r%. r-
ii_ tDi 0 CC C>J O : sZ* u C jl 0 N- <H 0 -i_ Ll. tH ll,. Ll. Li_ cu
^ i3 S3Q8 s §2 u & 8 S a 0 re S § I Ce § S 8 »FE Si I rE fe fe bb bb S Ce £ 3 S ^ S Sdb<38 a ^ S
cr.
3
cr-, cc
C 5 * ‘d ^
*•! cu CD _ O
CTl
X
rs-
Ll. t— i
*;r*
r-
Ll. Li_
•X-.
r-
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 35
91
x
£9
UJ
X
a:
s
>—« Ci_ X.
z> ^
e: x o
i.n
UJ ID *—4
Cl. D*C
►-« —J
>.n th
tiii^
x lo r-
( jD cr. <Ti
GD CD CD
'.‘•0 CM CM
h-CC
3 s !
Gi
_J
—1.
5-
o
8?,
U Q. CJ X
_J
• ac _j a. eg o'
xzarpzy
x
H—
Cl
22
c££
||
X
5 tH '
* i—co
fe
tH h~*
LlC _
eg x
SB S
*“> ©
UJ
Q
X h-
O ST O
: 12 \! 8 ?
o ©co 1ms
►-*_I >~4 Cxi. _| £
ssssss
-OCl
!8!
X UJ
UJ CC 3 I- ,x I—
© y > oct o
. rs t-> a- >c x Ln _j
yH'-ci >; .v a. ^ 5.
to^sio CIU
3 CO _J _)
•J X UJ CD •—«_| •—■« CtC_I
' c> u_ >c or ?< o ac
*—• JrjJ 5 O
U*! tH
X LO XLO CD
■«H rH CM CM l'0
, , . . ■wH rH ’rH •*■*< . .
CM CM CM CM CM CM CM CM CM CM CM
CSS IQ
© CO
i in CO
i ro m-
in co
n- in
to
cnii.
l— C-J
to
■HOCC
-Jo. ©
ce; u; r-j “
3
oJcjcc
5
ac x
ts.
EC X
^-fe©
o o
JJX
UL Cl£ r-J J- O > ’-* CO > -H •-< >_I >—i Is-_I LO
852?5S8§S3g5£g5g§53£
X
cocccoq
•-« CO Z> X >—*
3 o x co x <
tO
©in©in©in©in©in©ino-
tH x cm cm f -7 r -> Tt- rf LO lo to no to
r<i r*o i'-o r<i co co ro co ro co co co co
CM CM CM CM CM CM CM CM CM CM CM CM CM
LO CO CM
co r- x
X CO ©CO
CO liCpvt
88888
CO CO LO CO CM 00 CO LO CO CM CO
r- r- co r- x r- r- co r- x r~-
© © X CTj © CO © to x cr> © co ©
88888$ 888§8!S§u!ie8§ 88888g§
r-
CD
r-
■*H Q cli ou
Ll. GD ro o
r-
CM
0*1 C-N-
r '.i © M"
o o ox
r~ r- r- r%.
uj o u_ ox to ai
x ro O ro -.M CTj
x ® r— i* co x £i lo x Ci x in
8 OS u-j O x ■* C ' ^ M - -
ix^cs:
iisssicsfcSJEjeis®^"^®®#
opppxxx^o^xirj.-?^pxco^.pxxp^
#*#***
o
U'l
X
o
X
cl
*:••»****
O lOOI/TNCO
CM CM CM CM
Sggg:
o 5
o ”
Cn^x
_xx
X o
| L-ll-l
cdo'Ti
x>
X
xxcn
O *H h—
(— O '-O
Lo X
**■*■* X
X
Q
X
r-
r-
9
CM
CM
XX
X ui
R_
'7i x
XX
XX
I— X
Lo
o
U1 X
X
X
X X
CD
, UJ
—J I—
-J»—«
X
xoxx
_ O X
SgjrfS
^xo x —• i£r *—• e;i
U3 _
X_lx
>— X XX
3552
co a?
CO cv
in xi lo in g iQ
CO n- M- CO G3 X
i*Ti i^Ci »S) Cp -w—< -wH
'S' So®® '35
xuo
88
CC* C2'
u"« r-
CM CM
q LO (S- G'
r-? ro r<« T J"
”*H *rH tH ’•■■U
CS> 'ii CEi Cfci
x!
y—
o
XX
u.
I—«
•!»• O
tH to
tcm-
XIjI
X X
555i
' X
. h*
: ui
UJ
LU
cZ
‘5
X
X
XX
xD
OX
)—■
J!/I
^x
CD 1.0
12
O
CD CC -J
K-
* »-n
_j r>j
Cj
-J
_11—
S x
'O
'33 in ‘-O
in in m>
■»tH tH *>h
CD C5t' C3D
CDUD
CD
<:d -:d
CM CM
GD -H
•* H ■'H
a:- ce*
CM CM
CM^
*—I IJJ
O 3 r_i
I— -. 3 1— X
■<-i x cm i— x y i o x
* O rM X'Q X X _J L/i
CO X ^ ^
CM X C
o
8
Ln
XXXI
xXX
o 3 ; o
x •—i O
;=- x cti Ci x
T-l 3 X 1.0 x X
i_l |_ y-, IX X ►-< _J L-l X' X
2^835p^353S5
* *• S
ro U“* '3D U*D GD lT» C3> CM LO GD LO 'S» U“J GD LO
. * - ■ - • -- --‘ ^*i N N
•S' <ZD <3D
CM O'J CM
g
IX
rsi oc
*
oin
CO CO
CD '33
CM CM
X X X Ki
r. r- co x
' M- CO X CO
JSSS8
X X LSI
r- r - co
X X X O;
r- r- r- co
xr- C£i
r- x x
X X X CM X X
© xxx r- r--
XX© X tTipCCi Cl cc
NOO X X Cp M- X CO
XOCIX WifMSujSrlMOW
~ - -I © C^I x X G X © O X CO CO o
© © © © © © © © © © © © cm in co coxwH'tr^ r - r- ac ci © ro ini co co co x x x x x co in co x i x x x ^ in x x x m x
gggggggggggggSfsgggggsgggggggggggggggggiggggftiggliii
c~-,
UJ
uj
CM
«3D
Ci
o
ro
•Ti
X
tH
X
CTi
cr.
GD
i
CO
ro
N.
cr.
vH
r*-
H
CM
•3D
CD
CM
CD
r-
CM
GD
CD
<D
r-
GD
r-
r-
O
in
CD
cr-i
cr,
a-i
CM
LU
lO
«T»
CD
r-
Oh
CM
•jD
U_
Xi
GD
o
rf
CD
r-
H
r-
r-
r-
CM
•H
O
r-
GD
C^l
O
ro
UJ
u.
U-
GD
uo
ro
U.
GD
UJ
•D
•vf
't*
Cxi
'Ti
ori
o
CTi
«x
GD
X
X
UJ
CM
GD
CO
Ci
•uD
r-
•X
•r
ir
GD
r^.
r-
U-
p %
CD
•3D
GD
tH
CM
X*
r-
CD
UJ
•3D
CD
CM
•:c
CM
•3D
cc
•X
•3D
ID
•siD
X
CTi
LO
cr.
©
UO
UJ
r-
ro
CM
CM
GD
U_
•ID
CM
L L.
•3D
tH
UJ
•S»
r-
UJ
r-
©
Cl
r-
GD
r-
r-
cr>
rr i
•:s«
CM
eZi
-•H
CM
LjJ
I s —
X
L*>
X
CO
CM
or
CO
ac
r^-
CM
•3D
O
CM
‘3D
CM
o
CD
CM
Ld
U“.i
r-
X*
u_
CD
CO
CM
o
r-
X
ClD
cr-,
r-
X
•J-.
r--
Uj
UJ
8
C.
a-.
r-
X
r-
•X
r-
i 6 :
X
X*
81
CM
ro
o
8
r-
lO
X
tH
X
r-
ci
c£c?i
eg
cr*.
O
8
S3
'X
r*-
x<
X
R
•cH
'3D
FC
X
r-
ro
CM
88
m
X
555
‘4D
UJ
it
8
S5ai5fe5
r-
uo
tH
o
ss
X
X
8
ro
CM
5
'DD
GD
CO
©
CO
GD
0?
©
CO
©
CO
©
X'
©
CO
©
o-,
©
co
©
CO
Cft
Ch
x
az
CO
m
s
Q
o
Q
UJ
X
X©
tH
tH
CM
5S
r-
S
S
CTi
r--
15
gS
r-
15
Cl
r-
F5
Ci
r-
Ch
r-
15
ChS
r-x
r—
5
55
Page 36
92
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
UJ
c£
cc si
■ —J Z> Cfc! I>_I
< 0 : 02 : 00 :
•x a;
^ _ic£
cc o
si CO £ X C5 03
o
V-
ty
&
* ^
10
<T.
ON
•:m
O IT* IS* 10 ©
CD CD rH tH •.'•'J
CD CD «3D '3D CE*
n iX» ro ro r>o
OZQ
je*- e
to co in
cm rere
to cci ©
re re P)
_i>cc:r j
« o O as
oc £ 0 ►-.•
©in ©in
*t «*• in in
CO CO CD CO
I --0 (■'’> re re
© Cl. Cl. 1—
£££&
OO
Cd >■
* *
3 d O
mud a. -'' oc ■■
X © _J ©
©I uS —I Is-1> •— 1 _ICL M •-«
-iooxxoclncl
_i£e: JCo.u(jcj(j
o
' §5' d'
O CO
x a: o-a
r g' 3" g
>piooxa:oiiNCLNiipsjcLNa.NiirgCLNa r NCLN
o£ JECJuCLOCJCJCJOQOU CD CD CD CD CD CD O CD CD CD
3^
■s in © in co T-t in © in © in © in © in ■© in © m © m coin 3 in © in © in © in ©
co '.ONNQaicst-iTH cm cm re re ■+ -m- m inso co r- r- co co as as © © th *-4 cm cm re
3 CO 3 Cp .-4 .-4 .-4 ^■^▼4*4'H .-4 .-4 -H .^-4 tH »4 «-4 t-4 »4 --H .-4 -*-4 -«-4 CM CM CM CM CM CM CM
re iv5 re re re re [vj re re re re re re re re re re re re re re re re re re re re re re re re re
tn©
re '+■
CM CM
re re
CC
££
85
© o c5
US _J
_J rj
ui >c © as
>—i_lO")
■*
cm in © in
e- ^ in in
l4J
fv
CD
r-
in
vt-
5fcWK!SfcWK!Sifc8asslsa8
© CC' Cl
© r- r -
388
r- r- r- r- r- r- r- r - r>- r- r- r- r- r- r- r - r- r- r- is- r- r- r - r-rs. r- r- r- r- r-- r- r- r- r- r- n. r- r- r- r- r - r - rs. r- r- r- r- r- r- r-
o
s
a-6
X UN CD
ui^tDcc
0 *i Q to C5
i— Cn £ _!
_J_J O UJ©
_j is- > _n~ is c_i uj i— >—i cu i> i—i o
OtCOOIUllOlMClll-EOClll-CL
- u = £ui 2 e J'
Cl °~~l— Cl.
_© Q i
m. .J
UJ
“3
cn
r> ♦ cd
■—■ ww r— «_i uui i— l*_ O CD *—
fi= «.n ‘XI CtC JC UN UN QC SC «7i UN c*i
CD O
ct X
CD UJ
a? x
> 1-4 CD CD»
nrocDH-a-ja
cn 2 c UN UN CD CD c
c^:
5 CD
?• r~i on
ro
4 -
e: © © © © -jo
occyi :£ © © _j
i uj © x © JE
•• ”?»• I'l I i*» i ,
_l_i_i ai;
©
n © in © in © in © in ©
’■-j- to in •.£> id r~ r**- co co cr,
e-, ai as a-, ai'T, gs aS as as
CM CM CM CM CM CM CM CM CM CM
lOCO
■rf r-
r-
* © S
»-4 © © as cm as
iHOum C'j o
gj O -gj O tH ^o
co 51 is- co co ul r- © cr, lu r- co as uj r- © u. a-, in in in Si ‘ii uj r- r- r- uj r- r-
Komu. f -15 re © © re u. r- © re © re o cj © uj cm © P-ossirir
uS _J
I— UJ
Dal
tH CkJ tH
tH lU CnI ro ^ L~.l LLi Ur
_©©©UJO_ ._ __ . _ > o
© 5?
1 1 'ID'
© ¥ . .
^ i-* a, 1 —■
uc © © iz 1
>Sl © © -. uc u. -. © _ j o o © 0
_ © r-4 CCi xH >© '© © '-L UT lc
© © © © © ui '-n © i •
•-< © r-J hr Q
o
r -l CD ©
©
© ©
© ©1 I-. I> © »-H
©
c .1
©
© © I—I 1— ©
^©-‘se©
- us
1 ] S a. S n cl ai ii o us u S u iri u in Q n ‘ji ct © ffi e; u 'i Ji o r© u r a. 'j"i o u £ £ u. o 1 j- 0 c. £ u cn s: u n >-
♦ K- * ii! *■»•»■© * * 0 - *
in © m © tin © in n- ©
© © th cm cm re re ri rf
r^ is- iv- r - (v- r~ K n- rv-
CM CM CM CM CM CM CM CM CM
CO co
asN.
a,©
L 0 ©
co
J
CO © © U_ © © CCj la_ CO Ll © O
r~ is- r- r- r^- r- r- r- r- r- r-
© r- co as co co © © © il © in
I r. I r s r. 1 c s 1 r s .• *.
© cm © cm © cm © re
O CM O CM O CM O C'M O CM r© C<
r© 1 © CO © ©
r- r- r- r- ©
f© © CO © © CO ©
r-s © re © .. m © ©
4 I 1 'L' © © hi: © ©
•© © sj- 1 © © ■+ 1 © © ©
a 8 s-o
CO ©
r-r-
re ©
©^
G CD
r- co
lo r-
CD Q
dlsavj,
■H 1 © © '© O
O O CJ CO ©
r- r- r- r- ©
co © cj © © © ©
m i-1 re © cm © co
©©r-©©©©© ^
0 ©’* 0 ©U-'©£i v-l
© © © © r e '© © © a, © © uj © © ll cm ■
© ’cf o ©
Io CQ X ® yj 'H Tj
CD
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 37
93
-U
•:c
o
as
oidcnlco
iLl _J
ct; r> qd
►hXO^ 1
^ co 1 C ‘-n
UJ
H-
H-* CD ID
Cr‘ Cc.
oji-S
r-j ci. uj o
cc: ►-> cD Cc: o
3cn
UJ
pt!
:c
s
585
to Z3L
o8 w
Q CD O. CD
V 5, *^1
■CD
uj ;
O
cc
CD
oc
lO
CD
CD
CD
CD
co
CO
CO
CO
Ck.
CtC.
Lt
CXL
c*:
Ju.
li Z
ns f—
~ir
OC h~ CD
act— cd
pc!
►—<
UJ •—i
3L*U!
,—,
CD UJ Uj CD 1_iJ O
Cli
—4 Cr:
O CxL
O Lr.
►~t
H—
—l
—1
Cii
Ci^
r~>
5
_1
UJ
cii _
. _. -Da
X . J _l o C xi O UI o
M? -j u. _j id UJ ;■ I
o cc -. fie .. £r i— i/i
uioa w “i dt!
CC O _ _l _J Cl.
O Ll_l Q Cl,
ttSSS
cccc
_i_i_i
: cic 'X —j —i_i
1 2 t— x x x
i ►—< lo o o
ij_
i's-
i.~»
CJ W Ml IQ ax
Cxi N. CrJ CJ| IL. &> o
o
,1
Cl X CO U- UJ
r- o r- r- r-
r-
—. UJ UJ o
r- r- FZ r-
£S8£88 as888838888888888838
) rf r- X
jg&ag
r- r- r- r- r-
8ft 8
C5> CO Cl Cl 'Cl CO
■j? r- r- r- ■& r_
■S' O r- Ml llI iXi
'2. <§'Cy ft' ■£
? 1 sda?ld
•o co o r- *x» cis cm co c> co
th r- r- uii r s- r - r- r - r-
r- cc*
lO
CD
r-
Ch
vO
oi co co ro co co r o co co cc* co ^ u. co ii- •• o ^
'*LJ ^ if.» •H tH y“i rlLjLij. , CC x-J Cp u_ C3 Li_ Cn <f*
HiJ' r £'HuU'd^iilR lO '•J.* x-j L .• 4-j *H 111 Uj *.*'J LU T-i LI .1 Dj
HUGH o O nH O O cji CjJ CM tH UJ O UJ CM <dJ CD CM -H UJ O
£D U* 'A*
r-.: t-, r-
}-i J P> £>
LJ .» U» 'Si
vH Uj cm ul» CM tH cli lu x-J i^Ti
LlI '7m O CM ‘CD tH CD Co Lot -U'
tH
-
CM
CO
ro
lO
CO
in
Ul p
K— CtC dl
o
. Cel O
o
Oi CD
o
cc: cd
p
cc:
Page 38
Dr. Dobb’s Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, CA 94025
Number 22
94
•M
Uj
-il 'uJ
i '.n o cv:
i (J O
; “ a ;-1
I y*l U*l
•( cl-
_J
: oc x _j
■ isi—x
i —. i.n (j
oi ;j cj
J x
cd &!
_J
5ii^e5oSE“£L
V V \ \ 's ■*. \ v
-1 —J W4~ -• I _I -1 _| _J | I _I S \ -. S •. S S •
__J —I Cl_ I— UJ —I_11—•_|_I •—«_| I _J X I it—I II— UJ
■X' cc ar _j X' x x r-c x x x x x >' cc o cc a: x x cc uj El ns dk dk 3e ;e ue 3; 313 3t ■
c-i•-> o cri 'j joo J u j o j o iuuu_iuKixoooaaoaaooi
•' •> X '•
U.2 Ul
r|i- y. | ^
**• ••• *!D ■*•
: Z2 r£ CO Ll 3
iOOCji-u d
j£ sQ «! •- T » CJ U. T .J LO CO CT-. CJ Li. CM ID LO CO CO UJ xH rt f-__.. _ .__ ... . __ _ ____ _ w ____
CD UD CTi O U. C-J u7 CO CO O UJ ® f\l rf 1.0 OD X CJ UJ © C’J <t CO CO X £0 .
Irll
CD O 2i
(■:< 2
UJ
Q-r-JCC
CJ “> UJ
•—1 r-j c-j '
XXX'
UCtUJ,
I LU&
I O UC "*
; x ci ,
1 01 cj _J
: cc rr to
r cd c-? d
-e
UJ
-£Cc:uj
rHoct::
cz 1 ll. 'X
o i.n t
x uj
ET X X i
O «—• I
J vH uj CO Cp
.' CO
: o 0£ cm tie. to ct
oc 1 — ai!— xi— •;
1 Ul O UJ © LLl <
j cj o os c ac c £
Ci X . J Ci —I i —1 —I £
J X —I I -J..J —I ..J
£ UJ (CNXCNIIt-i:
: -2 j . ji CJ X' _J CJ Cl£ -_l '£_' IX .
CM iX
to it.
lt.i cE:
CD!—
CD 1—
CO 1—
CD r—
O UJ
O LU
sa
O ID
CD d»
Ct CD
CD CJ
d —1
d —1
CU_1
d d
—1 - J
d —1
—I _J
d -.1
1.0
cc:
LU
...1
iij
cE
xx
X
: 1 u :-c u_
' CD IX U-
: 'X cc o
i.n ~j
. Ij“l
: tLi o c»~
• nr. cd r —■'
«,*i
Cr. CD
O — I
—1 :<
r-j cc nr
•—;« CJ
O Z£ X
CO X II.
Cl. 1.H K-4
in o cu
1^1 cj
U“i i/*.i GD lO CC' CS* lO CS> C5D Li“ U" 'JD U“' CC* LT.« d' xH iO CI* LT* d' !j~< '.il» f - .;ri u“‘ •!£• U“!» d* lO d‘ L" O U“» CC* H '.'\i u“ d' u"> L»“' O IO LO d U~» d» LO
d» rH .h Cvj c j c-j r<i -^r -j- to co »:o cri -:d cd to ir« r%* r- r- cc* o:* or-. cr*» o-i cr-, d» d* tH th .;->j c j r-t> rc* -*■ u“* u** u“» vc» vo cr> <s» c-j »x» ro ■»jr uo U“»
c j c j <-j c j c-j c-j c-j c-j c-j CM oj cm cm i'-'j r *> r<i i-<» r-<i r-'« c-*'» c-o r<* .x» r-'i xr - r t- -c t- ‘t- rr vc to uo J •* t».»to or* u“«
Tt ^x*- T*- x* 1 .* xf •«*- -.f r-j- Tf x*- ^ X-J- -vf '«*- x.r x-^- Tf xi- -«f -T* v xf xj- -rr ^ ^ '*■ vf x*J* xf ■*** xf rh •«*- xr
uJ wL O II. uJ LiJ ID O u. ID lD CJ CD
S: £: ^ ^ :5 vj yj ^ S ^ ^ :|i
X X aulO cS TH ij 1^ f-^i 2S th Cj cil O 1 • '
u_ cj r-'.i x o o x x i_icj ® cj cj o x•
r- co
u*i r-
a i r-D
XI -v-l
Cj -n-l ... OT'i
X tH O X'
I.J. LU Ll- IU
r- r- r- r-
Li_lU IX £U
(■- ■ - r- i"--
r ■- Ijo cfj in x uo cj v~> u. 117 o u X; CO \t Li.
£ s x Se s x a x a ys» a a «>1 .x a a x c; . ^ ^ tb
C J O d' 1 CM O O CM O O CM O O CM d> O C- 1 d* U. CJ 1 • d* d' Ll.
k ,J ^ d'
*> n: k— r o <
^'SxfSlx * r ;i
}— J‘l O Cl. Ci ij‘i Cl. LU
CD -Cj
•X Cl. O X *-* Tsj .
H-ET^DCLZrX
IJV^CLZDOOHK
•X
* ->r Cl.
CM LO * D d» iT» 'x:» U") d* l
x^- x^f -rf- L" 'X' '•D r — t
CT7 CT-, CT-. 'Ti CT-. »7i Cf-. CTi (
r-o r- o M r o r<* «* *:• r *? js*> r
CD rH CD 1
xj* cd {— DZi tr t
2 $^S 2 siS£«
l. Cl. di_Id —I»
. *--* Cl.
: cl. r-j sr
: <_i —d —.
> to d< LO
• CD CTi • Ji
i CT-* 'P^i cr-.
• t o Fo r <>
LO X «x :
nr -Jo -
•:c
cl.
d io<£» i
O OH ’
CD CD CD *
Tt xf -wf '
IU-.IL, *—•
: o sr i --.' cd c
• CL. O 7* */l *■
•X
Cl
' (jO'T x ? iO» L
i CD CD d* d •:
X*- Tf 'C^ Tf ,
@
. r- & x
ouix ii.
!s!hi sx
I X X »• X X .H X o
x a: xx
I X Uicc I-I I
■O.E'MOZQ-N'tl
: —> —> 2 2 x U —> 2 1
XX X
Cl Ci_ Cl
i lO d* u~j d* tT* O L“> CD l
• di *7S CTS d* d* xH tH CM •!
i CD CD d* x—I xH vH x~l x—^ i
•xfxfxfxf-M--^f-x*-xf'
LD d
5 ^ 5 ==-;
. :•- Jl 3 x co
,a-ffl>>
iscto Xi
. i— e: a:
I— LUi
i—* X
._l O i
CL. CJ £
oi:
_i <
_11— oi <
xxxi
uceii
> Lil Xi Ul'
- r- co X''
I .H -H —I ■
- •*■ *r ■
CO lO £
(JI CTi (Jl >
Ll_ £j O
r- r- r-
£JLU Lj_XxXXX
r- r- r— r- r- 1- r- u-
Number 22
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 39
95
.“I tH
:c
X tJ i
re ssj
>3'__
X I x sc
.Vi yt* CO
r o r- -h U"i U*i CM CM CM CM CM CM
—, .~-s r-ij vd ^
;'3 CD r-t in '.o ^'i? 'i 1 S o
'*] iS l ” J in d d x> ixi in co cci cii
i>; .J 7C U. US '-‘1 o x> ra o *H o
.;_. i_i in us Ci£ D- ct cu CU cu cu
ij-i © o id x< id r- x> u~« id x> us.
«s! in in iis> m id in iiD on in u~< in id
cri as as iTi as or-i 5s os a. 5-. a. Os as
r:> r-
x
Q X ?0
X'Lu x -r
•A' 'S'li ' •!
iuX
'- ■•• n *c CO ® S' ~i X ifi vo ID '3
CO I— • • U. 10 LU IU (21 (21 •■£
X X
XXlL'aJ lu CC X
y? to ‘-I- 7t X, X t X r r fvj X
— gi rH I. L_ ‘MJ > 4 lJ •i Li~ •-*-» Ch O _
(Ti os r— t-i _ i t o c-3 r ■- *+■ co t co 6s o
© is?
vH l
X
’i x x
•± Q X id
X ”• i—l CO
Cur? ‘ J ' ‘
c- j ' c\i;d " -i co r- cJ ; f.;
_ -- ,___. :::• as :d .21 sd rs> 10 sd
UJ IU OS —I —I —1 C 2 > cjl 13 (21 Cxf ”i o X' I U CJ UJ '2b X' (2* 20 CJ 20 (5 1
X '. 2 ‘ '—I I— (5 1 d> © IU UJ UJ UJ llJ CJ LU (21 IU UJ CJ UJ CJ CU UJ (5f IU
•xi uj i— x xiu xiUJ iu iu i.u 'uj;u a u* lulu iu
LU m( 3(-(JQI U'nHOJLi.CJ U.I (.KC li_ X 2H Cl..
:z is or iu us co co oh r-j sr :n us cs uj iti-zccci-ooou xi:
Cl. US O U.I 1-1 Ci_ .-.O’— X> CC >X © O I—I O —■ I— X* ■—i I— US CC US 1 . J UJ CO
us ci_ ju ;c x us :■< ru cu ct :>- x. i-.u o _i x „.i x us o .u us cu us uj u_ cj_ o o
ID CO ID CD in X* iD 'S'»li"» 'SI 1 U“* '72' L~' iXi US' US' -X'
C'J C •■> CO ^ <#• ID u5 X> CC' —I .—I ( J' (' US' in (Li 0S5
ID ID D Ip US' US' uS' lO '.o 1 0 u'l 'X' '•£'' O ' £> '-O r-
CO CO CO vO 'X' Cu 'X' CC' 'X' CO OS CO CO 0.1 Cu CO CO
'••J US' CS» US' uS' X' tH X' u~' X* US' X' C-.J i'O US X' US' X' US' X' US' X' US' X' *X> US X* US X' US' X' US' X'
SO-IH C-.J X' CD tH i—I C-.J c-.j CO CO CO CS' CO 't- -<J- UD IjS '.o (O r- I 4 -- CO (Cl 'Ji CD CD -rH CU '(C Tj- UD
- r •- r-*- r — r — x* x< x* x> x> x* x> x> x« x* cd cd x* cd x< cd co cd x* x* xi C7i .A --i >-i —H .H --I .,-i
:o c.o Xi co co os cr. cr-. as as as a-, a. as as as cr. cr. as cr. as cr. os cr-. S-. .rr-. os a. ci. as a. a. cr. cr.
I— r-0 1.-0 lu Xi LU X 1 lC I.U X' Ll. X' i 0 XI
CM US' CM (M lu- 0 !u. CM -'f ro ID CM
X' 1-0 u_ X' US Si cr. ID. X' X' CM CM sj- CC 1 ll.
M US' sj- ?M X' to U ' CM CM US' S> US' f0 lu
UJ Lu US U- X* X'
JO MluOJ
:c _
5?
&
•?»c->■ o^rcvijpq uj ^ujt~ptti-' it.^:uj«coh-_ccuj2i2ru-2:3x:»- q-*Il3uj‘- nac
I ^ I M-V pi> Sz O I?i a: > O Lu O o O 1/1 X > O - Lu cS 2 lU22 Lu 3 tn X
o
r.xxrxaDo:
) a cj u o
CM
CD
tH
joScjOCioSciS
a:
UJ
Q
CO
:zkzk:
LU
cd ir> «d m cd to «x« in <s» ur« cr* cd u~i »d in -d in *.d to cd in «x* ud o in o ud cd in cd in cd in cd in cs> in cd cd in cd in rr, m cd cd cd in cd in cd
th cm cm ccj re* ^ lt« ur* r- r- o cd cm cm r o re* rt- •»** i/* 1 in \o r- cd g:« cm cm r-o ^ <x> cd tH t-i cm cm r <« in *X' ohh cm
5 J ^ yH r~l rH tH CM CM CM CM Cm CM CM CM CM CM CM CM CM CM r-0 (■'* M r - <i i'<i M i N *C* O I s ? C O vf-
'.U «.JJ U' *-u Cu Cu 'J,‘ I.JJ Cu UL' CO *X' CO 05 u-i CO CO CO CO 00 CC* CO CQ CO OCi CO COCOCOCOCOCOCOCuCO*X»CuCO
C\J fv Ci* 1-1 CM
,i -- rr lO L»D UD iT' U?
Gj Cu CO CO CO CO CO CC* CO 00 Cu oi
Ll H IX; to r-'X| CDcTj Ll. -H iX» LO r- CO X O llJ «X« CM Tt L£| o;i IX CJ tu O CM «f '-J CO X CJ UJ S' CM *X' CO X CJ UJ CD CM Vf ‘X* CO Ch COOlLrl
Page 40
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
96
CC l
r-
ro
Tp
xH
X
't-
lLLi
tH
r-
X
d.
in
UJ
•X
•7-i
do
'T
o
CE'
'H
xH
r*.
CD
©
r-
10
rj
H
cu
r-
CJ
'•D
r-
CJ
dS
CO
CJ
CD
O
a*»
CTl
rri
x
CD
•X
cc
CJ
in
rH
X
%Zj
•X
ch
X
da
m
X
re»
•X
Ll.
c-»j
ID
re»
rH
CD
X
rH
ro
rc«
ix
CJ
©
x
rt
cm
CD
r-
O
X
Ll.
CJ
CJ
r-
re>
r-
O
o:»
d:t
T - 1
os
LU
.• *•
C_a
u->
-r
Ch
•:c
CD
U-
c.
UJ
r->
o
cc
•D
*■'^4
nz*
re»
O
T—1
•X*
r —
CO
u
r—
CJ
Tp
CJ
Cxi
CO
r-
CJ
u_
•2D
r__i
•d
ret
re>
r J
CO
CD
CT.
CJ1
CO
ro
d
UJ
. j
Oj
CO
X*
X
C J
Li..
X
cr-.
•X*
tH
it_
cCj
CD
re*
O
rx
ix
un
l' *1
x
CD
»*,-*!
r-
r-
•M
CD
r-
o
.j
CJ
X'
r-
rji
r-
1^1
r *»
rH
in
’•n*
©
CJ
UJ
•»S%*
re*
ID
05
cc
l L
cD
cc
U.
UJ
'j-
Id
CD
iD
X
X
©
C
O
•j.
■' 1
cm*
rH
r-
•!ji
CJ
CD
r-
Cxi
U.
r-
CD
r-
CJ
CJt
r-~
UJ
rx
r-'»
o
8
cr-.
ro
•X,
ro
u
CJ
UJ
rx
&
ro
Li
8
in
X
ID
8
S8
8
UJ
Li-
8
ij
s
.x!
yn
iH
d2
UJ
UJ
X
Ll.
Q
cj
czj
•n
UJ
CO
ro
•rS‘
•X
re>
Ul
do
o
ret
.dt
cm
X
'*
X
LL.
fx
LO
o
rx
in
CJ
X
ix
o
O
co
CJ
o
■CJi
•d 1
ft
vH
T
X
X
X
P0
ll.
i- i
CD
x
da
in
UJ
cc«
re«
UJ
r
^r
u_
.• •»
dj
id
cj
X
Tp
r-
x
CJ
rx
cZi
tH
r-
o
X
px
Q
•s*
'X 1
CT|
r.__
CD
CJ
r-
•2D
co
•2?
co
co
•2D
co
05
©
co
•3?
co
CS»
«*i*i
'2!
CO
rt'i
....
C«D
•s*
CM
CM
lO
re*
Tp
in
m
X
X
rx
ix
CO
CO
ai
•T'i
•±
X
CD
cc!
•iji
f •»
d>
UJ
UJ
UJ
UJ
UJ
UJ
LiJ
UJ
UJ
UJ
UJ
UJ
UJ
UJ
UJ
UJ
LD
UJ
LU
LU
LD
LD
UJ
rx
rx
rx
r-
r\»
rx
rx
r-
rx
r-._
p--
r •-
px
pX
P--
P-
r--
r-
r-
r-
P-
P-
r-
U-
•H
di
ll.
■X
r%-
r-i
X
LT.»
•X'
u
X'
'X*
•:o
tH
xH
x>
-H
•X'
UPt
IT*
CM
CM
r»
a.
?j
r-
'••■J
t
•: • j
•.-•j
Ll.
in
rP
•:-J
-p
C'J
rP
*fxl
*P
in
*5*
TP
UP*
■*p
■H
vdl
•X.
•Xi
•d'
■x*
Ci‘
•-X*
•Xi
•T.
CD
tH
r:-i
up»
■J-l
•X'
LU
CO
xH
rji
«i
ISI
CM
•X'
X
•*P
UJ
Xi
CO
r-
•:-j
C'J
C-J
•>J
in
in
•:-.j
•: • j
TT
CM
pP
■^P
CM
CM
CM
CJ
UP*
ret
PP
ret
X
li.
X
xH
X
U“.t
X'
X
ue«
'r
X
X'
XI
CTi
ret
LL.
•X»
X
re»
cr.
CT.
X
cr.
CJ
X
r-'.'
r-
'.-.J
O
CJ
c-*j
T T
ue>
re«
rP
in
pp
LO
CM
■•P
IO
to
IO
•p-
IO
to
Ll.
LD
ret
cTj
X'
o
CO
•2?
•X*
•d*
•X»
CJ
CTi
•X'
Up*
U.
rP
r-
in
Ll
n
UP*
xH
re*
X
•x>
CO
1 *-
•j:
f__i
CO
Cxi
yr
ret
•:m
•;-j
-+
C-J
U*i
b"i
U“>
UP*
^P
U-)
tp
n-
u_
CM
CJ
H
Ll—
»et
X.
-■i-
X'
iC»
X*
in
uP*
u"
cv
U-
CD
•X 1
•X*
r-
UP*
CD
CJ
re*
«x*
•X*
X
•.IT
f-
•,e>
UJ
•. 'J
•.•■j
T-
to
r-c*
L) .•
•'t-
u
LL
l v J
*.-*J
re*
u.'
pp
M-
ul*
X'
CJ
re*
dj
•X.
1' • '
dj
LD
m
ret
u_
X
ret
d»
Li-
C*»J
'■p
•X*
UP*
■T.
CM
CD
X
ret
•d>
•_U
id
o
•.■•j
-j-
Li ^
Li—
r T
11
CD
PP
UP«
•a)
uP*
•f j
IO
Jm
Pi
u.
lO
X
•:r
•X
•"Et
•X
dj
i H
•X
•X»
•Ti
•Ji
r-7
CIi
Li
X
X
io
CD
|T,
•p
■X'
TP'
XI
r-
'.-.j
•Ji
CO
'T
’X
T
i •.«
U1
'.■•j
irli
•:-.j
•r
U '
X
T
i]*i
to
i’-.j
CM CM
•Pi
in
lT.i
ro
CD
iH
o:>
•X 1
CJ
LD
CO
•X'
in
H
C\J
tH
©
'•D
X
X
X
dj
•X
•x>
CO
•ji
o
1-
Cu'
Q
•,\1
'j-
C'J
TT
TP
(M
l>J
pp
If?
PP
©
to
u.
rf
^P
Ll.
CM
n
re>
r-
CO
X'
CO
CE'
CO
•3T>
CO
CD
CO
dk'
CO
•!D
CO
cz*
CO
•ZD
■:o
<5
05
CD
CO
CE*
CD
CO
•7S*
ro
o
LD
ID
X
X
CD
CD
rH
tH
C'-J
r-.i
r?
ret
’T
m
O' 8 '
X«
X
r-
r-
CO
to
■T,
CT.
•X
X
a
UJ
IU
LU
UJ
UJ
X
Ll.
U-
X
X
Lu
X
X
X
Lu
ul
Ll
Lu
'X
u.
Ll.
u.
u.
U-
u.
Ll.
X
X
P*»
f'X.
P‘-
P--
r*-
r-
r--
r-'-
r-
;
p--
p*-
r--
r-
r-
X
P*-
r-
r-
r-
r-
r--
r-
r-
r.
r-
r-
t
C>!
O
CJ
tH
ID
CS'
UJ
m
p
r-
X
lx
X
Xi
r-
Ci
'•D
X
xH
dj
X
X
'X'
CM
CTi
X
di
p
n--,
CTi
X
xH
X
dj
X
X
IO
•T.
c-i
rH
ID
X
r-|
'T
r-s-
iU*
T—1
r-
X*
0.1
X
r-
X
dj
IX
X
c j rd 55 fx -h
CJ
05
x»
«7»
tH
rH
r-
tH
Ll.
•Ti
CJ*
•4.1
CM
r-
F-
CJ
CJ
LO
Q
p-
CJ
r-
X
a:
rj
cu
CJ
CD
CS 1
•X 1
p-
C3P
UJ
CJ
•X*
Q
XI
d5
X*
X
X
o
•r-*j
dj
CTj
X
Lx X
X
CO
rH
X
dj
'•D
•P.
xH
dj
X
xH
iu
xH
d.
*Jj
•s*
X
m
lO
Xi
CO
ro
X
X*
•'•■J
r-"»
Ul
X
X
X
X
X
X
X
X
CTj
L.t
r-
CC
O
X
r-
CJ
* — 1
OJ
r-
X
dj
r-- *25
CM
CM
tH
re*
Cj
TT
'sO
rH
rx
UP'
xH
CM
tH
CM
xH
i'j
X
•T-,
•s*
CD
CJ
r-
CO
r-
CM
CJ
X
r-
CU
r--
ro
rH
Ci
rH
X
dj
rd»
X
*25
CM
X
CD
•D
Ul
dj
CJ
CM
da
CD X
X
di
dj
cr*
CO
X
rH
da
X
X
CD
xH
X
d5
xH
CM
CM
05
CJ
aa
o
X
•d*
ro
•T.
CJ
ro
X
CD
X
X
X
r•**
r-'*
r-
o
X
X
•dt
r-
CE*
X
r-
rdt
r-
tH
*:m
r-
cofi
rx
CJ
tP
o
r-
Tp
xH
r--
U*j
r_J
az
XI
ll
X
r--
X
X
X
CJ
X*
X*
CD
ro
ro
CJ
«!D
IX
CM
r-
X
r-
IX
X
CJ
X
ID
ID
dj
*X
CO
CM
X
X
Ll.
X
da
da
•d-t
CM da
da
CO
Tt*
r-
da
xH
da
X
X
X
•55
ID
X*
Li 1
Li..
X
dj
•55
^p
da
X
•dj
ID
X
in
Cli
CM
Ul
CJ
cr -1
-P
P*-
O
r-
wJl
cD
•d 1
Ll.
r-
•:-j
rj
r*-
xH
cm r -
X
dj
PP
re.
■d'
xH
r-
LO
1 ^1
r-
•:*j
r--
CM
l*x
up*
•X
i'- i
X'*
O
•!D
O
IX
X’ 1
r-
Ll
ro
CJ
CM
CM
CM
CD
X
r-
r-
.*, j
LD
l'M
CO
.-•5
dj
X
Cli
r-
X
•ro
*d*
x. CJ
da
?••
X
da
‘P*
• M
X
X
LT*
da
C^j
cc*
Cit*
x-J
cr.
■p
-p
X
X
da
X
<o
CM
X
OC*
,• •,
•dt
It-
c£
pp
vj
CJ
rd
wJ
1 -
iu
d>
r-
*.M
o
r- x
< J
IX
«d»
r-
X*
rd
X
*-J
IX
xH
X
•d*
P-
X*
X*
X
•:u
o-.
o
x«
s*
.v*
a>
r-
Cli
r-
r ‘i
|X
o
fx
X*
X
ro
tH
fO
Tv-
't
cZj
i •—
8
X
X
Q
o
r-
IS
fc'
8
X
*:j
8
cr.
XI
da
O
X
fx
88
da
rx
CJ
Ll
IX
ret
tH
•5‘
8
X
CJ
8
re*
tH
8
X
da
o
c«i»
Co
da
r_i
uP*
CM
8
CJ
fx
8
8
8
ID
'P
CJ
ro
X
8
8
|X
•ID
r^.
LU
8
8
xU
CJ
ro
CD
X
r-
CM
X
8
X
X
8
dj
■’P
dj
r*-
8
X
tH
ro
CJ
X
•X
CJ
cr,
rd'
t-*!
LU
8
rd‘
r-~
888
88
X
X
8
8
8
CO
r--
ro
tH
dj
CJ
CM
T-i
X'
X
in
Cu
CM
o
in
X
8
da
>'-J
X
rx
O'.
'U
CT,
CJ
Ch
CJ
in
CD
xH
x-l
X
r--
ft
LU
X
ro
X
-cH
•X
CJ
CD
8
X
rx
UJ
■ — 1
cr
ro
X'
IX
CD
o
8
X
X
«x«
dj
CD
ip^i
CJ
LU
8
8
8
i — i
X
|
CE«
X
X
CM
888
X
r-
8ft
tH
T
dj
T' - -
re«
rH
8
r ■—
»n
CO
pp
ro
rj
ft
o
CM
CTi
ID
•vD
N
eft
8
8
8
3
8
d>
r-
*D0
ro
ft
8
E
dj
xH
CD
8
X
rx
o
CM
X
r--
ro
o
X
tH
X
tH
CO
rs»
CO
CD
05
l*\»
C»5
CD
or*
•25
CO
•?»'
CO
CD
CO 3*
«s»
X
•3»
CO
CD
CO
CD
•:o
^7*
•:o
•s*
05
•35
•X
CD
05
•35
05
aw
‘rt 1
05
X*
w
r«5
CO
r»5
CO
•25
05
•25
CO
*25
05
ro
(Tl
Ch
X
az
I'Ll
lJ
r j
r,
a,
p
UJ
U.I
X
u_ CD
a
vi
rH
'■M
CM
r--»
ro
PP
X-
U~*
to
' L*
*sD
!'*-
05
CO
Ch
•Ti
X X
OJ
CO
|- ‘i
i J
dj
CJ
UJ
LU
LL
X
X*
•S
tH
rH
r, t
j
r
CJ
CJ
O
r i
CJ
CJ
r .j
r j
l_J
CJ
uo
o
o
dj
dj
dj
Cl
Ch
dj
dj
dj
•~J
X
di
X
dj
X
o
Ci
c
CJ
dj
X
dj
id.
•dj
LJ
dj
dj
dj
id
CD
UJ
UJ
UJ
UJ
r._
P--
r-
r-
r*-
r*-
f's-
r-
r*-
r--
r<-
r-
r--
r-
r- r--
r--
r.
r-
r-
r-
r-
r--
r-
r-
p-
p-
Ps_
rx
fv.
p-
fx
r*—
r*-
r--
r--
r-
r-
p-
p--
P--
r-~
r-
r-
p-
P-.
P-
p-
r-
r-
r--
X
r-
CJ
X
rH
CD
ft
ft
S
X*
rri
di
X
X
r-
X
X
rH
tH
8
8^
CM
CJ
ro
rH
CD
CJ
CM
Cl
X*
Cpj
X
CO
rH
in
X
DJ
CD
OJ
X
CD
CJ
•25
X*
X«
ro
rx
u.
u.
TP
ro
C-.J
•35
ro
o
CM
r-
rH
•45
CE.
<Xi
o
CO
II,
rH
in
ro
05
CD
CJ
ro
CO
•2D
ai
i j
r-
X
r-
X
rH
X
X
r-'t
da
X
X
X
X
•Pa
Tt'
•;r:
da
da
X
05
rx
•S*
rj
rx
•!D
X
•2D
‘vO
•2j
re*
o
X
ro
r-
lL
da
X
CD
rH
ro
rH
CM
CM
LO
da
ft5
da
CC*
X
o
r-
X
X
ro
X
rH
rH
CJ
Cli
X'
r-
X
1
CM
r-
da
Ch
X*
k*-
UPt
CO
da
Ch
CJ
nr.
ro
LU
O'.
o
CO
rx
X
pp
CO
•S*
on
•dt
X
rH
X
CD
u.
X
X
a-.
X
•dr
rH
Tp
rH
CM
CM
'sO
dj
X
p<i
u.
CJ
p-
CM
tH
r.i
tH
X*
rH
H
CJ
CP.
CJ
‘S'
•S'
X
ro
rH
ro
X
r-
^888^18
LU
C
X
TP
8
cr.
X
■"D
05
CD
05
CD
CO
<25
■--•j
CD
05
X*
05
X
00
X
X
CD
rH
rH
r'-j
CM
ro
ro
rP
Tp
•jpt
in
'•iD
'45
r-~
CD
CD
CD
CD
CD
CD
CD
CD
X
CD
CD
X
X
05
CD
A
p-
rx
r-
P--
P--
r-
P-
rx
P--
P-
r-
! -
IX
1^-
$88
X
05
8
8
CJ
CJ
dj
CJ
X
IX
8
dj
CJ
7B
X
rH
8
<o
CD
X
tH
8
CTi
DO
LD
r-
'45
'45
X
CD
CM
X
X
•o
X
CD
rH
rji
CO
XIX
tH
TP
CM
Ch
IX
dj
CM
P--
X
LU
Tp
CD
rH
rj
rH
CM CM
X
X
da
O'.
•01
di
X
dj
dj
CJ
U.
rH
X
Ch
rH
HO
ro
tH
o
•D
Oi
CJ
p-
X
o
I s -
rH
tH
IX
X
in
COda
r-
•45
X
rH
CM
Ll
X
CM
X
X*
*45
X
X
CD
X
"■r ro
TP
X
TP
tH
o
r-
dj
CM
r-
ro
X
r-
da
LO
Ur
r-
o
X
m
UP*
r—
•^
X
.* •
CM
•x>
X'
rH X
X
r-
rH
Ci
rH
X
o
t-
X
X*
r-
DJ
CJ
r-
X
CD^I
lL
CJ
X
X
-H
CM
u-
X
CM
CJ
X*
C£
X
."•'.I
P-U.
IX
1-0
X
rd
dj
fM
rx
X
CM
IX
ro
Ct
p-
x«
X
rx
dt CO
xrx
to 8
o
r-
cr.
0-1
CO
rx
X
rx
a,
CD
8
8
s
8
CJ
r--
re*
rH
da
CJ
X'
88
8ft
CJ
re«
2
82ft
X
r--
LJ
8
IX
TP
X
CM
8ft
05
•S' O?
CD
05
X
•55
X
CO
5 s
X
X
05
CD
CO
CD
X
rx
CO CO
ch
Ch
X
X
CO
CO
o
CJ
X
dj
X
X
X
X
Cli
UJOJ
UJ
CD
CD
CD
CC .i
CD
X
CD
X
X
CD
CD
CD
CD
p-
r-r-
r-
P--
r--
r-
r--
r-
pv.
N
p-
!X
rx
P--
p-
fj
X CM
CO
X
X
CJ
r-
r-
r-
in
CJ
S'
CJt
X
!t2
r-
Ll CJ
r-
O
X
rH
CM
<25
rH
rH
TP
fx
©
CJ
X
CC
rj
azco
da
CO
IX
X
in
r-
X
X
CM
CJ
tH
-x
c2a
CJ
ro
da r-
X
IX
ro
da
X
■25
r-
r-
CJ
X
r-j
r-
CJ
o
coco
CJ
0 s .
o
0*1
in
r-
dj
CJ
un
dj
d.
LU
•r-j
Tp
CJ
IX rH
CJ
CJ
rH
fX
da
•25
CM
OJ
©
CJ
TP
X
X
un
r-
X da
X
X
Ul
05
in
X
da
r-
r-
Oi
TP
rH
o
X
Tp
CM CJ
Tp
rx
CO
X
CJ
rx
CM
r-
r-
CJ
Tp
X
CJ
Li¬
X
da ‘35
X
*n
CO
ch
05 da
IX
IX
rH
X
•:o
UP*
da
rH
o*S
Tp
X
r-
ro
CJ
CD CM
rH
rH
i* *i
r-
rx
un
iX
X'
X X
rH
CM
cc»
TP
IL
X
iX
X
X
xH
U - '
-j
X
OP
X
Tp©
rH
CM
X
S'
ro
o
rH
r-
r-
dj
X
©
Li¬
Lh
£J
X rH
X
CT.
r--
X
•25
Ll
IX
CJ
•d'
r-j
az
da
da
CJ
«.
• •-
tH -*h
r -~
X
PO
dj
X
r-
rH
nj
<fM
X
c-o
CJ
r-^
ij
X*
XX
X
CD
TP
CTi
IX
H
X
r-
r-
•'—!•
UP'
©
©
•5*1
ro
UJN
X
X
s>
r--
I'O
X
•r
p'-
K.
r-
X
i-*Pi
a:
Lpt
8
CO CD
QrH
CO
rH
X
CM
8
X
ro
CO
ro
?
X
Tp
ft
CO
UP'
•25
X
CO
X
•25
r
CO
rx
©
co
CJ
O CJ
r i
i* j
o
CJ
CJ
(j
CJ
CJ
CJ
CJ
C j
CJ
tj
o
r-
r-r-
Id
IX
r-
IX
r--
r-«
IX
rx
rx
Px
r-
rx
r--
r-.
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
97
Z-80 RAM TESTER
Dear Dr. Dobb’s: Received: 77 Dec 7
In the August issue of DDJ you carried an article by Jim
Butterfield which listed a RAM test program for the 6502.
This article in turn referenced an algorithm described by
Knaizuk and Hartmann in the IEEE Transactions on Compu¬
ters (April 1977). Enclosed for your perusal is an assembly list¬
ing for the Z-80 version of this program. Some frills have been
added for those lucky people who have the TDL “ZAPPLE”
Monitor. These allow the user to specify the start and stop
addresses and print out the location of the error byte.
I have found this test program to be exceptionally good as
well as fast. It even found a pattern sensitive 2102 that I had
saved for the occasion from a previous hair tearing session.
Keep up the good work!
John MacDougall
110 North Gordon Way
Los Altos CA 94022
o
+
a
X
Q
z
•H
tq
c
X
a
H
>4
H
i j
>4
a
u
o
X
o
a
tH
z:
X
X
a
X
t—*
<
£
o
C
X
a
a
c?
>4
a
O
a
z
o
c/J
o
a
CO
o
a
a
H
43
<c
z
a
?:
j:
z
£
1—1
H
z
<c
tH
C)
z
o
(H
>4
ttl
H
a
a
a
r-5
Z
H
£
>4
X
1—1
a
>4
a
X
H
X
a
£
rH
a
£
a
H
a
£
X
a
a
to
o
CO
o
X
X
tH
X
X
z
z
H)
o
o
X
c
M
a
-3
£
X
o
X
>4
X
X
CJ
O
X
X
a
X
a
X
o
o
c/J
C—<
o
tH
X
X
a
IH
C3
a
o
tH
o
a
z
o
•«H
V
£
o
rH
a
rH
a
o
a
o
z
X
o
a
O
rH
43
H
X
<
F—4
X
-£
tH
a
L3
z
IH
*=c
z
<=c
<c
£
m
X
CJ
a
a
z
H
o
a
a
rH
£
H
c/>
r
X
£
o
X
o
o
r d
a
z
d
a
X
X
z
O
c/J
o
Q
a
a
o
H
a
a
<C
X
O
rH
<c
X
IH
o
a
a
O
o
\
X
t—<
Z
z
t—•
a
rH
C/J
H
a
a
a
o
X
£
tH
H
X
c/J
a
X
rH
X
H
a
o
o
X
X
X
X
a
rH
c)
a
X
C )
Q
z:
a
(D
tH
<£
c-
£
£
tH
X
£
>
z
o
a
d
.s
H
<
IH
H
H
o
a
o
a
a
a
O
o
o
C3
O
a
o
o
o
=c
(J
a
<
•a
O
C/J
o
a
a
a
£
a
o
a
o
X
II
H
H
u
o
•VJ
tH
X
o
a
£
X
o
Z
a
a
o
o
X
'O OBJ) O
in a z: =c < z. o
X H H O H - O tH -
o a £ (D C/J a O £ <
: c a
. -H J S> i
: -*-> <c o
> 3 o s
o
g
T3
O *“ Q o m H
on c* vOOOOQre
O O =T lA Z z H Q < J
~ x - x x h h <d o ih z
2 ifljj<i;aojQos 2 : l a, to d
x x J ni a: o Q
a) < a j h
£:>£0 £ozo< , -3 £ c o a a a
0£T£01 l Ua < 'jQ h J'HJJJ Z
43
3 ••
•• O O
Q G H
O -O OQ Q
Z 3 < Z
»-« X •/) H d
£ a • - co
O O t- m C\l X X q
O O O O X a
3 C- d O CT> X d vO O out] ? <- o o o
J 4 in (\1 b CM lQ o «- C- q O O 0 CJ
- -
Q J O
CM (M O
O O
O O q
lO
=t, C 3 ON
on c\j -d CJ
•o 'fl q x cm in >n c- o <x o a x o «— in o < o x cm .o
in in in in in in in in n n -o o ~o o 0.0 o h e b
ooo oooooo ooooooooooo oooo
ooo ooooooooooooooooo oooo
C *H b0
0) L C
-*-> 3 -H
< 4-3 0)
: w c to
> tD o c -
4-3 (DO)
■» "O CD C
. (D (D £2 o
) G a
• H Cm (D Ci_i
> -H > O
-C C0
. * CO £ to
I 4-3 (D
^ c to H
I 3 - CO
W to O S-
> a> o -h
1 G Ou 4-3 <D
. „ cd -C
0 Cl) to o 4-3
-G » O
4-3 O rH
O <D
bO rH E
G <D rH -H
£ n) *3
4-3
o rH to
CD -G -H *H
■C D D £
O -H C ^
5 3
TO 4J
C t) jj <a!
fti CD
43 (U
c (fl .
O CD t3
•H Q. (D CD
" c t,
B k D II)
O >
O CO o o
I -H 4_3 o
: x a o
o o h *
1 OJ B M
> b0 *
, L 3cc
> o O o
> o
to (0 H
it) £ td
c c 00
. o c .«
i o c
J CD O
< to 3
> O I CM
I CM I O
OH a
H X Q
<C O
O H Z ZJ
O '/> M -
X r x-
x a a x
x x
-2000
O H t-* 5 i
2 to to H
o ^ o x
Muza-
X O H C*»
J 2 Q
O 33 z i
x q =c
h 2 H a
x! d H H I
X S ^ i—4 *3) «aj
O
2 r i< (b Z a] J
i- Ct, o x a.
H D Jd d 2
a H H t I O
CO !0 9) O Z O
H Q O M
h d d 2 ;*
X (H E 2
>4 CO O ^ CO
O CD H H O CO
a z a
z h ^ x
^ - Cx, U 'd C
O CO <C z H O
Z O d S O X 'H
O- X .£ x3 4-3
O - • Cd Z (0
X CO H xj CO > O
d d d X d O O O
N>hO<^2HH
G X X d
O =Z O 3
ClHZ Z '
•H CO M c- a ■
E £ a H <
X H x
xx cm a x
x- <£ a o a o
X H Z * O -
O CO -d C X <£
a a a
a a X I—I =£ ,_!
-t: c a h
-> co CO £ CO £
XXX
X X o
< a a a o
o co co o
a a a
=» a a a >
o =c < o
s o o o s .
a o h x
a o x
o o o x a to
< o x o o <* z
x c
<Z OJ < rH X X CD
x x a x a o £ a
Oaaooaaa
Cm o Cm o
X H «“ Q_ JH
3 co a H 3 cO
4JctoifiH iJcj;< ao
w ^ ^ i 2 n ^ «oa -
co £ o a to u o z <
CD (D
5 C
•H .H
43 43
2-3 -3 2 s 3 a a
P oa>a.z>.
G<£0<££ o X X o
ao£oa 0 o£oa£i
3 3
I H CD lQ CO X ••
: X X .. x *H X H
i <c a a a c a a
I H q 5 iO E-« H O
■ co • a • • - a a
o
- m . - *
^ ^ 2 ° cm a x ao
X CM O CM mm 4- (MO
a-o o ooo oo
(MXOi^nCMOX ooo •— o O X *-
o in o x x o a
a a cm a d cm a x 3'3aoixt^ o cd <c a x)
o a cm dmmm.=j-c_>ooc'tMcQCMonxocn«—
22^22- d ’“° ri ^‘ c ' <c 3 d X O CM 111 E <C a
x2222 0r_,— ,-r " r-r-r ' r_( A J CMCM<MC\JCM
22222°°°oooooooooooo
OOOOOOOOOOOOOOOOOOOO
O X
X
a «- a o
o ^ o •-
O O ifl OO
o o o
Q t*- -a o 3> x H o
O 4- X CM b CM b O
a a a a o o
CM CM CM CM m m
oooooo
oooooo
cm in so
mmmm
oooo
oooo
a a x «- m =t in o
mmmd-^ d- a a
oooooooo
oooooooo
Page 42
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
98
MINI-EDITOR FOR 8080 PILOT
O
-O
O
O
Cx3 D
m C\J
O O
O O
<X
•il
Q
o
Z
r-i
s
E-*
cc
<c
H
CO
O t*
cn LH
g O
O o
o o
o o
o
*2 r-t
H
IO X) J (\|
f'o o m
o o o o
o o o o
f H Cl.
^ -J O
OH dh
Q C -s co
o
J3
£
O O o o
o o o o
o
QC H
O CO
_ -z <
O M fcH
S (O
il, Cl, a.
I
b0
C
X
<D
Q C- Ci, i] a Cd C
(\J CQ Cl, Cl, O CQ CM
C\l Cl, Cl, C *-of Ox O
m (\J Cl 4- Cl, E O
c\j o' ci, o co cu a
O t- Cl. O r- O CM
a o *- u cq jo <c
on o a vO i. *- m
O Cl. jo ca o m a
o «- o «- o a
O Q Q < in vO oo
mumcL.CL.O'-
onoox>*-a^r
in O Cl. «- vO CX 3 Cl,
Q a O in Q Cl, o
amoaocM*-
o q < »- m oun
O O O VO O ^ r x.
a o o .a so c- *- o>
(MOODOO-OO
CMCMa«-C^OQO
iM m i, ^ C- CM O O
^■Qooao«—o
(aooocMOOon
r i, C*. Q u O' a ^ CQ
a a- cm n c- ci. Cl, in
Q Cl, < Q in C' OQ
c_> cl, on o o a- t- a
CM a •- Cl, O O a- O
O on Cl, x. rvj o o o
aojoaooma
OOCMiOOUCM
o
o
o
o
o
o
o
o o o o o
cm on =r m o
o o o o o
o o o o o
Tim Scully is a friend and business associate who is an
inmate at a Federal penitentiary. Despite that, he’s busier and
more productive than most prople I know. Tim has been
designing biofeedback equipment and doing biofeedback
research for many years. He is now working on a doctorate in
psychology; his dissertation project involves researching and
developing bio feedback systems and techniques for use in drug
rehabilitation. He is also publishing articles on biofeedback
and microcomputers in People’s Computers and, as you see
here, writing articles in other areas as well.
With permission from prison officials, Tim has begun devel¬
oping a microcomputer-based system which will allow a
cerebral palsy patient to communicate. A knee switch on the
wheel-chair system will enable the patient to construct
messages which will be displayed on a CR T. He plans to make
his work available to the public.
In addition, Tim is teaching a computer class to fellow
inmates, using the computer system belonging to the cerebral
palsy patient. Tim is hopeful of eventually obtaining a
computer system for the prison, despite the fact that prison
resources are scarce and he cannot solicit donations. But
while donations can’t be solicited they can be accepted so long
as no strings are attached. Contact me for more information
if you have equipment to donate to Tim.
Phyllis Cole
Editor, People’s Computers
Box E
Menlo Park, CA 94025
Tim Scully Received: 77 Oct 23
I have a Poly System 4 with 8K of RAM (from 2000H—
3FFFH). A few weeks ago I decided to get PILOT running
on this system, and translated Dr. John A. Starkweather’s
8080 PILOT 1.1 (from May 1977 Dr. Dobb’s) so that it would
live comfortably in Poly’s memory, starting at 2000H. After
writing a few simple PILOT programs, the need for an editor
was clear. Being short on memory, I didn’t have room for an
elaborate editor program, I wanted to squeeze a mini-editor
into the space between a jump to the start of PILOT at 2000H
and the actual start of PILOT at 2100H.
The program listed below was hand assembled because Poly
has neither an assembler nor a printer. The program uses
several subroutines from the Polymorphics 4.0 monitor ROM,
and these are the only labeled calls in the program listing. If
you have another hardware configuration, you will want to
replace these calls with some of your own. Here’s a brief
description of what each one does, in case you don’t have the
Poly monitor.
WHO — fetches a character from the keyboard and returns
it in A.
WH1 — prints the character in A on the TV screen, recog¬
nizes a carriage return as carriage retum/line feed, recognizes
CTL Z as a jump to monitor command (so I modified PILOT
to use CTL B where Dr. Starkweather used CTL Z), and recog¬
nize CTL L as a command to erase a line (so I modified PILOT
to use CTL L where Dr. Starkweather used CTL U).
DEOUT — prints the contents of DE as a four digit hex
number.
MOVE — moves — BC bytes from an area starting at (HL)
to the area starting at (DE) . . . only useful for moving from
higher addresses to lower addresses.
The mini-editor displays one line of your PILOT program at
a time, beginning with the first line. At the beginning of each
line it displays the memory address (in hex) of the first char¬
acter in the line (you can easily delete this feature if you don’t
need it). The mini-editor is designed to drive a video display,
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 43
99
3-WAY BASIC MARRIAGE
Received: 77 Nov 18
I have been most pleasantly surprised by DDJCC&O after
many rip offs and disappointments (i.e. Logic Press). I would
gladly pay twice your subscription rates. You are truly doing
an outstanding job of providing a needed service for the
private computer user.
I have adapted the LLL BASIC which was printed in
DDJCC&O for my home made 8080 system and of course
the first thing off I want more goodies. It seems to me that
the Extended Accuracy Arithmetic package by Dinely in
Vol. 2 No. 3 of DDJCC&O would be a useful addition to
the BASIC interpreter. If there is any one else of like mind,
I’d appreciate the chance to correspond with them. Another
major feature which I am now adapting for my system is
Dr. Starkweather’s 8080 PILOT. I plan to combine the LLL
BASIC with PILOT using the source line editor in LLL BASIC
to edit PILOT statements. Dr. Starkweather’s 8080 code
for PILOT is beautifullly organized and commented and his
“Guide to Pilot 8080” is also an exemplary job.
If you are interested, I can send a souce listing of my
results of the marriage of those 3 contributions from
DDJCC&O.
Yours Truly,
B. Reeves 2-18 Patpong Road
Bangkok 5
Thailand
Many thanks for the compliments! And yes indeed to that
offer. We’d be most pleased... sounds like a “marriage made
in Heaven ”-TR W
but could easily work with a printer if you don’t mind using
up some paper.
Because of the small memory space available in my system
for this editor, it does not use a cursor to indicate where
insertions or deletions are to be made. Instead, if insertion is
requested, a character will be inserted just before the first
character presently being displayed. If deletion (rubout) is
requested, the first character on the display will be deleted.
The spacing feature of the program allows part of a line to be
displayed so that insertions and deletions can be made in the
middle of a line. When first called, the editor will display the
first line of your program. The editor commands are listed
below.
Carriage return — displays the next line
Line feed — backs up the display the previous line if you
are looking at a complete line. If you are looking at part of
a line, it backs you up to the beginning and shows you all of
it (useful for seeing the results of insertions/deletions).
Space — skips the first character of the previously displayed
line and displays the remainder of the line, useful for editing
in the middle of a line.
CTL B — returns to PILOT if you called the mini-editor
from PILOT.
CTL D — inserts a space just in front of the first character
on the display.
CTL E — inserts a carriage return just in front of the first
character presently on display.
Any other control code - will be ignored (except CTL Z
if you are using the Poly monitor ROM).
Any other non-control character — will be inserted just in
front of the first character presently on display.
RUBOUT — deletes the first character on display.
203E
23
I NX H
move ahead one character
203F
C31820
JMP 2018H
display the remaining line
20b 2
FE7F
CPI 7FH
check for 'rubout'
20bb
C26220
JNZ 2062H
if not rubout, keep looking
20h7
2ao:-:20
LHLD 200EH
fetch starting address
20b A
E5
PUSH H
copy HL
20b B
D1
POP D
into DE
20b C
010000
LXI B,0
initialize PC for use as counter
20b?
3501
KVI A,1
set up to check for end-of-program flag
2051
2B
BCX H
2052
23
I NX H
2053
OB
DCX B
count one character
205b
BE
CMP M
check for end flag
2055
C25220
JNZ 2052H
if not end, keep counting
2056
2A0E20
LHLD 200EH
fetch starting address
205B
23
I NX H
skip the character to be rubbed out
205c
CD0001
CALL MOVE
move the rest of the program dov.n one byte
205F
031*20
JKP 201BH
display remainder of line (after rubout)
2062
FEOD
CPI ODH
check for carriage return
206b
CA1620
JZ 2018H
carriage return displays next line
2067
FEOA
CPI OAH
check for line feed
2069
C27*20
JNZ 207BH
if not, keep looking
206C
2AOE20
LHLD 200EH
fetch start of line
206F
2B
DCX H
line feed '-acks up a line
2070
2B
DCX H
back up
2071
7E
MOV A,M
fetch character
2072
FEOD
CPI ODH
look for carriage return
207b
C27020
JNZ 2070H
and keep hacking up until you find one
2077
23
I NX H
move ahead to start of line
2078
C31820
JKP 2018H
and display it
207P
FE02
CPI 2
look for (TIL B
207D
C8
RZ
CTL B returns us to PILOT
2075
FEOb
CPI u
check for CTL D
2060
CAB320
JZ 20B3H
CTL D inserts a space
2083
FE05
CPI 5
check for CTL E
2085
CAP620
JZ 20E&H
CTL E inserts a carriage return
2086
FE1F
CPI 1FH
skip any other control codes
208 A
DA 33 20
JC 2033H
bv fetching another keypress
208D
2A0E20
IH ID 200EH
fetch starting address
2090
F5
PUSH PSW
otherwise, save character so we can insert
2091
3501
KVI A,1
set up to look for end-of-program flag
2093
010000
LXI B,0
initialize 3C for use as counter
2096
2B
DCX H
2097
23
I NX H
2096
OB
DCX B
count one character
2099
PE
CMP K
check for end flag
209A
C29720
JNZ 2097H
if not end, keep counting
209D
5b
MOV D,H
209E
5D
MOV E,L
copy HL into LE
209F
13
I NX D
move program
20A0
7E
MOV A,M
up one character
20A1
12
STAX D
; to make room for
20A2
IB
DCX D
; insertion
20A3
2P
DCX H
;
20Ab
OC
TNR C
; count one character
20 A 5
C29D20
JNZ 209DH
;keep on if not last character
20A8
ob
I'JR B
20A9
C29D20
JNZ 209DH
20AC
FI
POP PSV
;fetch back the character
20AD
12
STAX D
;and insert it
20AS
23
I NX H
2 OAF
23
I NX H
space ahead
20B0
C31&20
JKP 2016H
;and display the remaining line
20B3
3520
MVI A,' '
;insert space
20B5
C36D20
JMP 208DH
20R8
3E0D
MVI A,ODH
;insert carriage return
20HA
C3&D20
JMP 206DH
listing for
mini-editor
2010
210030
LXI H,3000H
start of program storage
2013
3'EOC
MVT A,0CH
2015
CD2bOC
CALL VJH1
clear TV screen
2016
220E20
SHLD 200EH
store starting address
201P
2 tr )E20
LHLD 200EH
fetch starting address
201E
E?
XCHG
move address to DE
201F
CDD103
CALL DEO’JT
print DE as b hex digits
2022
E?
XCHG
restore address to HL
2023
3520
MVI A,' •
2025
CD2b0C
CALL Vfril
print a space
2028
7E
MOV A ,M
fetch character from memory
2029
CD2b0r
CALL VJH1
print it
202C
72
MOV A,M
fetch it again
202D
23
I NX H
set up for next character
202E
FEOD
CPI ODH
check for carriage return = end of line
2030
C22820
JNZ 2026H
if not end of line, print more
2033
CD?' V )C
CALL WHO
fetch keyboard input
2036
} 520
CPI ' '
check for space
2036
02b220
JNZ 20b2H
if not, keep looking
203P
2■0S20
IP!LL 200EH
fetch starting address
Page 44
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
100
THE LAST REHASH OF BEAU HEX?
Some letters on the subject
Dear Dr. Dobb: Received: 78 Jan 24
I have been noticing for some time, a gradual trend toward
pseudo-religious fanaticism in many phases of computer
related activity. We are condemned to everlasting failure if we
don’t organize our programs like bands of angels. Some other
fate awaits if we don’t throw away our flowchart templates
and take up weiner diagrams, whatever they are.
Those of us who know from long experience, that older and
other methods work well when employed by competent
people, have tended to dismiss these cults as the products of
people who sought to cure their basic inability to organize
their work logically as they went along, and then found that
they could make (lots of) money by selling their ideas to the
ignorant. We recognized them as rather childish simplifica¬
tions of the situation, shrugged our shoulders and went on
about our business.
The letter from Mark J. Nitzberg, in issue 2/9, reveals that
this may have been a mistake. We have a young person of
unknown experience level, who raves over the virtues of
hexidecimal notation, and condemns octal, both with religious
fervor, and with arguments which have nothing to do with the
problem at hand.
I think his letter has gotten me in a violent enough mood to
respond in kind, and I have prepared a counter argument in
the form of an open letter to Mark:
James C. Matthews
Dear Mark,
I read your letter endorsing the use of hex. It seems that
you are quite comfortable with this notation. Probably you
can even do hex arithmetic in your head. However, there are
two errors in your assumption that we must all abandon octal
or suffer some everlasting (but undefined) torment: 1. The
fact that you find hex easy to work with does not mean that
all of us are equally able to manipulate large-base numbers,
and; 2. You don’t understand the purpose behind the intro¬
duction of either the octal or hex formats. I shall try to
explain these points, along with some other areas about which
you seem a little fuzzy.
First off, storage space, and the waste or conservation
thereof, has nothing to do with either form of notation. Very
little, if any, data is ever stored in either. The beast can count
neither to 8 nor to 16, but only to 2. Everything is stored and
acted upon in binary. If we really wanted to save paper and
keystrokes, the thing to do is develop a printable set of 256
distinct characters. Then a simple 8-key pad would suffice
for data entry. (Don’t laugh-many users of ARPANET’S
DNLS have become surprisingly proficient at entering ASCII
data with the mouse buttons and fingerboard. They use the
normal keyboard for initial entry, but only for very long
changes while editing.) Of course, we would need to memorize
the entire set of 256 characters, and do the binary-to-
octabinary (seems like a good name for our new notation, we
can say OB for short) in our heads, but then that’s a small
price to pay for all the paper we would save.
Octal appeared very early on the computer scene. The
human brain seems to have something against long strings of
repetitive characters. Binary, having only 2 character variations,
reaches the rejection point very quickly. The limit seems to
be about 6 bits, because most people who work with Baudot
teletype soon learn to read the 5-unit code from punched
tape, but very few ever learn more than a few characters of
7-unit ASCII. (I do know this may seem to go against what I
said about the DNLS users, but in that case it is broken into
a 4-unit string for the left hand and a 3-unit for the right.)
In any event, when memories were slow, and word lengths
were growing by leaps and bounds to minimize the number of
required accesses, people soon found that they could not deal
effectively in the language the Machine was compelled to
speak. People were used to dealing in decimal representation
of numbers, and octal was the nearest subset of decimal that
used an even binary set. Octal, therefore is purely a matter of
convenience for the human in dealing with the blinkey beast.
The development of hex is a compromise. Since most
applications of computers require some nibbling at, if not
actual crunching of decimal numbers, most machines become
proficient, via hardware instructions, at either XS3 or BCD
arithmetic. (You mention the 8080’s DAA as though it had
something to do with hex. It doesn’t, it’s for BCD.) The
great sages in their ivory towers, who spew forth nionitors and
operating systems, discovered that ASCII is effectively a super¬
set of BCD, and they could save a few bytes of code in their
creations by dragging the humans across the boundary of
decimal to something easier to do on latter-day machines.
And what it was, was hexidecimal. Hex was rather well
accepted for several reasons: a. It came with the machine. If
you wanted to talk to it, you learned hex. b. Doing arithmetic
with alpha characters mixed freely with numbers enhances the
mystique of the profession. While most octal users, in my
experience, do simple arithmetic in their heads, most hex
users seem to do their’s on paper. This is almost certain to
awe the onlookers.
You are totally wrong about any advantage of hex in mem¬
orizing the 8080 instruction set. In hex, there is no visible
relationship of families of instructions, and you must
memorize the entire set of over 200 instructions separately. In
octal, the relationships are easily seen, and there are only
about 20 basic instructions and variant rules to memorize. This
is a clear 10-to-l advantage for octal in that most precious of
all storage units, your one and only brain.
You also seem to fail to understand the logic behind the
“amazingly unorthodox” split octal representation used when
8-bit machines have 16-bit addressing capability. This again is
simply a concession to the human, allowing him to see the
contents of each of the registers holding the 16-bit number,
separately, as they really exist internally, and as they must be
acted upon, in most cases.
And finally, some philosophy. You did not have to compile
that letter. Most people who become addicted to bit-flipping
will be exposed to all manner of number representations, and
hopefully, will be able to choose one that is right for them. I
don’t have to write this, but I am a technical atheist, and take
pleasure in espousing things looked down upon by those who
allow some religious fervor to override their logic and
condemn things without good reason. I don’t believe that any
Supreme Being gives a hang how we structure our programs,
draw our flowcharts, or represent our numbers. God, and the
religious orders which help to channel some of our energies in
search of truth and goodness, have far greater concerns in
getting us to live with one and another, and with and upon this
poor old Earth. You are wasting the energy and enthusiasm of
your youth in pursuit of some rather nebulous dragons. Please
try to find a channel that will have more lasting and meaning¬
ful results than trying to teach people to count on all 16
fingers when they have only ten.
Very sincerely, 2028 Merrily Dr.
James C. Matthews Montgomery, AL 36111
Dear Sir, Received: 78 Jan 16
I am new to computing, so was unaware of the octal/hex
controversy. Needless to say, I prefer octal, since there is less
to leam. What hex proponent can state that hex never led him
into error? (more)
Number 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
101
SWTPC CT-1024 AUTOMATIC SCROLL
Dear Mr. Warren, Received 77 Dec 12
Having implemented the modifications suggested by Mr. R.
Lynn Smith in the February 77 issue (pp. 25-27), I found it
desirable to keep full control over the cursor (using the
SWTPC Cursor Control board and Screen Read board) rather
than have a cursor stuck at the last line of the screen.
This can be achieved in a very simple fashion, as described
next. The purpose is keeping all standard behaviour and all op¬
tions normally functioning, except when a line feed is issued
with the cursor in the last line. In this case the text must be
scrolled up, and the new line “cleared”. The solution given can
be used independently of whether or not the 64 char/line
option of Mr. Smith is implemented. It requires only 2 more
IC’s: a 7420 quad NAND and a 74193 counter.
The present situation (with or without 64 char/line) is
shown in Fig. la, and the required modification in Fig. lb.
When the cursor line counter (1C34) decimal value is 0-14, the
behaviour is as if nothing had changed. When count 15 is
reached, further “up” counting is inhibited. Instead, the next
“count up” pulses increment the 74193 counter whose con¬
tents are added to the address portion A5-A8 (addressing the
memory), thus causing scroll-up. This counter/adder configu¬
ration (74193 and 74283) can be built on a 1” by 2” PC card
attached to the memory board, thus requiring only one “ex¬
ternal” connection.
Software aspects. In order to maintain modularity and flex¬
ibility, a difference is made between “line feed” and “cursor
down” when the cursor is in the last line. The first causes
scroll-up, the second causes cursor wrap-around to the first
line. Thus, programs that consider the CT-1024 as teletype re¬
placement always use “line feed”. Programs considering the
complete screen field as basic output record format use all nor¬
mal cursor positioning commands (up, down, left, right) etc..
Note also that IC34 has still its preset capabilities available for
those wishing to use direct cursor positioning.
I hope that these suggestions will be helpful to some
readers.
Sincerely yours,
R.T. Boute Francis Wellesplein 1
Bell Telephone juClub B-2000 Anterwerpen (Belgium)
4 MHZ Z-80 A BOARD BY NORTH STAR
News Release Received: 77 Dec 20
North Star Computers, Inc, announces a 4MHZ Z-80A
processor board (ZPB) for use in S-100 bus computers. The
Zilog Z-80 A executes compatible software more than twice as
fast as the 8080. The North Star ZPB will operate in systems
with or without front panels. It includes space for IK of 2708
EPROM.
Other features include auto-jump startup and vectored
interrupts. Available as a kit for just $199 or $259 fully assem¬
bled. EPROM option costs are $49 for kit and $69 assembled.
For additional information write: North Star Computers, Inc,
2547 Ninth St, Berkeley, CA 94710, (415) 548-0858.
Machines know nothing of the controversy; they work in
binary. Octal and hex are merely convenient ways of restating
binary for the sake of humans. A manufacturer wishing to
please everyone, could issue two sets of manuals, one set in
octal, and the other in hex. (Or could they?)
The new fact seems important to me, that innovative manu¬
facturers aiming at mass markets (“home computing”) have
stayed with octal. I mean Heath and Radio Shack.
Yours &c;. &c., P.O. Box 1818
Joe Schram Washington, DC 20013
COMMUNICATIONS APPLICATION
FOR THE HANDICAPPED
Tim Scully, who has been designing biofeedback equipment
and doing biofeedback research for years, is currently an inmate
at a Federal penitentiary where he is working on his doctorate
in psychology; his dissertation project involves researching
and developing biofeedback systems and techniques for use
in drug rehabilitation.
With permission from prison officials, Tim has developed
a Poly-88 based system which allows a cerebral palsy patient
to communicate. A knee switch on the wheelchair enables the
patient to construct messages which are displayed on a CRT.
A complete description of the system including the assembly
code listing has been published in Volme 6, No. 5 of People’s
Computers (March/April issue).
Tim is hopeful of eventually obtaining a computer system,
despite the fact that prison resources are scarce and he cannot
solicit donations. But while donations can’t be solicited , they
can be accepted so long as no strings are attached.
For further information contact:
Phyllis Cole
Editor, People’s Computers
Box E
Menlo Park, CA 94025
Fin- 1»
Present situation
r
1 cursor up *
IC34 3
4 2
5 6
7
|(J3 pin 5)
|count down
| count up
! line feed
1 (IC30 pin 6)
1 cursor down
^ 1
74193
| (J3 pin 3)
1 MAIN BOARD
1
J
Page 46
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 22
102
dr. dobbs journal of
COMPUTER
C
Running Light Without Overbyte
Number 23 _ March 1978 Volume 3, Issue 3
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
Status of the USCD PASCAL Project — Kenneth Bowles
Report on efforts to implement PASCAL on various processors
SAM 76 — Additional Comments — Ancelme Roichel
Addenda to the documentation published by Dr. Dobb’s
SOFTWARE
For 6502’s
Renumbering and Appending BASIC Programs on the Apple-II Computer — Steve Wozniak
Apple’s R & D Head tells how
A KIM Binary Calculator — John Eaton
How to solve those problems you never had until you had a computer
For 6800’s
STRUBAL: A Structured BASIC Compiler — Robert Grappel
For Z-80’s
A Z-80 Tracer — Arthur W. Cline
For 8080’s
ACT — An 8080 Macroprocessor — Alex Cecil
PL/M Listing with documentation
alisthenics
60
rthodontia
16
46
4
13
10
11
20
© David Dameron 1979
LEST WE FORGET.. .
Technology often has a way of absorbing us in its intricacies
to the extent that we can lose sight of the implications of what
we are doing. It is for this reason that we have decided to
interrupt our “bit fiddling" for a brief moment and refer to
the ad which appears on the inside back cover of this issue.
It is certainly not the policy of Dr. Dobb’s to preach on
controversial issues. But we who are interested in reason and
“artificial intelligence”-still an extension of human intelli¬
gence-should stop to consider that there exists on this planet
another race of intelligent beings which is being systematically
hunted to extinction.
There are, of course, innumerable other causes we could
choose to comment on, but the slaughter of whales has
symbolic value. It asks a question of technological society
that strikes at the relationship of technology and industry
to intelligent life. We at People’s Computer Company wish to
express the hope that the machines we play with be used to
aid and increase living intellect and not to destroy it.
Tom Williams
KAPIAR ERRATA
Dear Tom, Received: 78 Jan 23
Here is an errata sheet for some of the goofs in my docu¬
mentation. (Sorry ’bout that...)
p. 31, column 1, line 8 from bottom: insert ‘macro’ before the
right paren;
p. 32, column 2, line 9: ‘a@b@DEBLANK(b)’ should have
been ‘a@DEBLANK(b)’;
p. 32, column 2, line 12: ‘in’ should be ‘is’;
p. 32, column 2, middle: ‘b@@a’ should be ‘b@ @a’;
p. 33, column 2, line 26: ‘<parm 1>, . . .’ should have been
‘<parm 1>",. ..’;
p. 34, column 1, line 22 from bottom: ‘pairs of a’ should have
been ‘pairs or a’;
Finally, all the examples of ‘&’ as a continuation character
were too long to fit the DDJ 2 column/page format, so the
lines (as printed) are broken without continuation character,
and continuation character ‘&’ is not followed by a new line as
intended in the example.
Cordially, 24225 Summerhill Ave.
Steve Newberry Los Altos, CA 94022
OTTAWA MICROCOMPUTING
Dear Dr. Dobbs, Received: 78 Feb 6
There is a club called “The Ottawa Computing Group”
which is very active locally. Although electronic components
are more expensive here (import duty, etc.), I would estimate
there to be well in excess of 250 microcomputers operational.
Interest is very high. Being the personal owner of an
RCA COSMAC, I am disappointed that the use of this process¬
or is so low. There has been very little mention of this
processor in Dr. Dobb’s which I hope will be rectified in the
future. Perhaps an article by yourselves discussing a few of the
nice features of the CDO1802 over other available processors
might help stimulate more interest. In my estimation, the
1802 is a superior MPU but few people realize that fact.
Keep up the good work and keep those issues coming.
Yours truly,
D. C. Underwood
Thanks for the encouragement and yes, we’d love to
publish items of interest on the CDP1802 if folks out there
would care to send us something. -TRW
6502 DISASSEMBLER FIX
Dear Dr. Dobb, Received: 78 Feb 22
Since my Basic language disassembler for 6502 appeared in
your Volume 3, Issue 1 as “Challenging Challenger ROMs”,
I have discovered an omission. I somehow left out the ROR
and ROL instructions. Apparently they don’t occur in the
ROM areas I was examining at the time. The ROL mnemonic
was in my data list although the decoding scheme I used would
flag it as an illegal opcode. ROR is missing entirely. A proper
fix would insert ROR after ROL in line 60 and completely
rearrange the table in lines 210 to 520. This simpler fix also
works. Just change the following lines.
70 DATA SEI,STA,STX,STY,TAX,TAY,TSX,TXA,TXS,TYA,ROR
230 DATA 10200,35222,56100,56100,56100,35203,3203,56100
250 DATA 29300,2221,56100,56100,7200,2200,40200,56100
260 DATA 39100,2210,40130,56100,7300,2300,40300,56100
270 DATA 8200,2222,56100,56100,56100,2203,40203,56100
280 DATA 44100,2304,56100,56100,56100,2303,40303,56100
340 DATA 38100,1210,56130,56100,28325,1300,56300,56100
350 DATA 13200,1222,56100,56100,56100,1203,56203,56100
360 DATA 46100,1304,56100,56100.56100,1303,56303,56100
Add
611 IF C=56100 OR C 1100 THEN 1000
Delete 630 and 631
I’m enjoying the controversy you have generated over the
Heathkit systems. Although I don’t use their computers, I
did order some cassettes from the, believing that I could be
certain of getting quality suitable for saving programs. The
result has been disappointing. Although my Challenger uses
the Kansas City format for recording (like Heath), all the
Heath tapes consistently aquire a few errors in recording,
and one is totally unusable. I don’t have these problems with
other cassettes, and my recorder is the identical GE model
sold by Heath. Buyer beware.
Sincerely yours, P.O. Box 831
Stephen P. Smith Parksley, VA 23421
BEYOND THE 8080
Received: 78 Feb 10
Certainly. Am glad to tell you why I do not wish to
resubscribe to your Journal. After two years of subscription,
I find that the same people who started the Journal and
writing for it still are doing so, still talking about 8080 mater¬
ials, little being written or published about 6502 or others. To
check this imbalance, just take any five issues, as example,
inventory those issues for content — by microprocessor type —
and see for yourself. In other words, it appears to me that the
“world” has passed you by. You are “out of step”. True, you
have a market, but you are missing the far bigger and more
diversified market that is there and needing your kind of help.
If you change, I change. Until then, good luck. You had a
a good idea!
C. E. Brown
Rt. 1 Box 159 B1
White Stone, VA 22578
Fact is, we probably are behind the times out here in 8080
Land. But we’d be more than happy to publish stuff on
6502’s and others if folks would write it up and send it to us.
Dr. Dobb’s exists to help pass software around to the eager
hands of users. _ jp \y
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 3
105
RENUMBERING &/\PPENDING gASIC PROGRAMS ON
THE APPLE-II (COMPUTER
BY STEVE WOZNIAK
Apple Computer
20863 Stevens Creek Blvd, B32
Cupertino, CA 95014
The laws of entropy insure that the line numbers of a de¬
bugged and operational BASIC program give the appearance
of having been selected by a KENO machine. In fact, while
several texts detail how the boundary conditions of a KENO
game lead to predictable outcomes, finished programs seldom
exhibit this property. Many a time I have spent an extra hour
retyping a finished program while spacing the line numbers
evenly just to make it “look good”.
Another difficulty which I have experienced is joining
two BASIC programs into a single, lafger one. This ‘append’
operation is easier to accomplish by hand than renumbering.
The sophistocated user can examine the BASIC memory map
and perform some manual manipulations to join the programs
providing that the line numbers do not overlap. Still, the
manual append operation is highly prone to error.
The APPLE-II BASIC user now has a solution to these
needs in the form of a hand- or tape-loadable program
RENUM/APPEND, described herein. The CALL command
is used to activate one of three machine level programs. The
renumber operation (RENUM) requires user specification of
the origiinal line number range over which renumbering is to
occur, the new initial line number to be applied to the range,
and the new line number increment to use. The example below
specifies that lines 200 to 340 be renumbered starting with
100 and spaced by 10’s.
RANGE BEGIN 200
RANGE END 340
NEW BEGIN 100
NEW INCREMENT 10
A second RENUM entry renumbers the entire program,
relieving the user of the need to specify the range begin and
end parameters. The append operation (APPEND) reads the
second user (BASIC) program off tape with the first in mem¬
ory.
Renumber and append error conditions (memory full and
line number overlap) are detected just as in BASIC. In case of
error the user is notified and no program alteration occurs.
Using RENUM/APPEND
1. Load RENUM/APPEND (* 300.3D4 R)
Note that the high-order bytes of page 3 are not loaded,
preventing inadvertant alteration of the interrupt and user
function (Y c ) vectors. The ‘ ’ is generated by the
MONITOR, not the user.
2. Load a BASIC program.
3. To renumber entire program:
POKE 2, START L User must supply low and high
POKE 3, START H bytes of new STARTing line
POKE 4, INCRL
POKE 5, INCRH
CALL 768
number.
User must supply low and high
bytes of new line number
INCRement.
(does not alter locations 2-5)
Note: START L is equivalent to START MOD 256
START H is equivalent to START / 256
4. To renumber a range of the program
POKE 2, START L
POKE 3, START H
POKE4, INCRL
POKE 5, INCRH
User must supply low
and high bytes of re¬
number range start¬
ing line number.
User must supply low
and high bytes of
renumber range ending
line number.
(does not alter loca¬
tions 2-9)
5. To append program #2 (larger line numbers) to program
# 1 (smaller line numbers):
(a) Load program # 2
(b) CALL 956
Be sure you are running the tape of program # 1 as this
command will load it.
(c) If you get a memory full error then use the command
CALL 973 to recover the original program.
POKE 6, RANGE START L
POKE 7, RANGE START H
POKE 8, RANGE END L
POKE 9, RANGE END H
CALL 776
Errors
1. If not enough free memory exists to contain the line num¬
ber table during pass 1 or RENUM then the message
‘(beep) *** MEM FULL ERR’ is displayed and no renum¬
bering occurs. The same message is displayed if not enough
free memory exists to hold the product of an APPEND. In
the case of APPEND, the user will have to type the BASIC
command CALL 973 to recover his original program. The
user can free additional memory by eliminating all active
BASIC variables with the CLR command.
2. If renumbering results in a line number overlap (detected
during pass 1 of RENUM) then the message ‘(beep) ***
RANGE ERR’ is displayed and no renumbering occurs.
This error may mean that one or more parameters were not
specified or were incorrectly specified.
Cautions
1. When appending a program, always load the one with
greater line numbers first.
2. The user must be aware that branch target expressions may
not be renumbered. For example, the statement GOTO
ALPHA will not be modified by RENUM. The statement
GOTO 100 + ALPHA will be modified only to reflect the
new line number assigned to the old line 100.
APPLE-II BASIC STRUCTURE
An understanding of the internal representation of a
BASIC program is necessary in order to develop RENUMBER
and APPEND algorithms. Figure 1 illustrates the significant
pointers for a program in memory. Variable and symbol table
assignment begins at the location whose address is contained in
Page 4
106
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
ihe pointer LOMEM ($4A and S4B where ‘S’ stands for hex).
This is $800 (2048) on the APPLE-II unless changed by the
user with the LOMEM: command. A second pointer, PV
(Variable Pointer, at $CC and SCD) contains the address of the
location immediately following the last location allocated to
variables. PV is equal to LOMEM if no variables are actively
assigned as is the case after a NEW, CLR, or LOMEM: com¬
mand. As variables are assigned, PV increases.
Figure 1 - MEMORY MAP
LOMEM (start of variables)
($4A,4B)
BASIC
VARIABLES
PV (Variable Pointer, end of variables)
($CC,CD)
constants are in this form including line number references
such as 500 in the statement GOTO 500. Constants are always
followed by a token. Although one or both bytes of a constant
may be positive (less than $80) they are not tokens.
Variable names are stored as consecutive ASCII characters
with the high order bit set. The first character is between $C1
and $DA (ASCII ‘A’ — ‘Z’), distinguishing names from
constants. All names are terminated by a token which is recog¬
nizable by a clear high-order bit. The ‘S’ in string names
such as A$ is treated as a token.
String constants are stored as a token of value $28 followed
by ASCII text (with high-order bits set) followed by a token
of value $29. REM statements begin with the REM token
($5D) followed by ASCII text (with high-order bits set)
followed by the ‘end-of-line’ token.
Figure 3 - ITEMS
BASIC
PROGRAM
V -*-PP (Program Pointer, start of program)
($CA,CB)
first line
HIMEM (end of program)
($4C,4D)
The BASIC program is stored beginning with the lowest
numbered line at the location whose address is contained in
the pointer PP (Program Pointer, at $CA and $CB). The
pointer HIMEM ($4C and $4D) contains the address of the
location immediately following the last byte of the last line of
the program. This is normally the top of memory unless
changed by the user with the HIMEM: command. As the pro¬
gram grows, PP decreases. PP is equal to HIMEM if there is no
program in memory. Adequate checks in the BASIC insure
that PV never exceeds PP. This is essence says that variables
and program are not permitted to overlap.
Lines of a BASIC program are not stored as they were ori¬
ginally entered (in ASCII) on the APPLE-II due to a pre-
translation stage. Internally each line begins with a length
byte which may serve as a link to the next line. The length
byte is immediately followed by a two-byte line number
stored in binary, low-order byte first. Line numbers range
from 0 to 32767. The line number is followed by ‘items’ of
various types, the final of which is an ‘end-of-line’ token
($01). Refer to Figure 2.
Figure 2 - LINE REPRESENTATION
high
f $01 I
length line number items
byte
'end-of-line'
token
Single bytes of value less than $80 (128) are ‘tokens’ gen¬
erated by the translator. Each token stands for a fixed unit of
text as required by the syntax of the language BASIC. Some
stand for keywords such as PRINT or THEN while others
stand for punctuation or operators such as *,’ or *+’.
Integer constants are stored as three consecutive bytes. The
first contains $B0-$B9 (ASCII ‘0’-‘9’) signifying that the
next two contain a binary constant stored low-order byte
first. The line number itself is not preceeded by $B0-$B9. All
Constant:
low
high
$B0-$B9 value
positive
token
Name
(ABC) :
$C1
$C2 | | $C3 |
negative
ASCII
positive
token
String
Constant
("123"): | $28 |[
$B1 1 | $B2 | | $B3 |
| $29
quote
token
negative
ASCII
quote
token
REM:
I $5D |
i 1 1 i r
1 | $01 1
REM
negative
’end-of-1ine'
token
ASCII
token
Tokens: $00-$7F
GO TO - $5F
GOSUB - $5C
THEN In - $24
LIST - $74
LIST , - $75
STR CON - $28
REM - $5D
EOL - $01
(tokens used by RENUMBER)
Renumber — Theory of Operation
Because of the rigid internal representation of APPLE-II
BASIC programs (insured by the translator syntax check),
writing a renumber program was a somewhat easier task than
it would have been on many smaller BASIC’s. Fortunately
all constants in APPLE-II BASIC (including line number
references) are preconverted to binary.
The normal renumber subroutine entry point is RENUM
($308). The RENX entry ($300) conveniently sets the
renumber range for the user such that the entire program will
be renumbered. RENUM extensively uses SWEET16, the
code-saving 16-bit interpretive machine built into the
APPLE-II (Byte Magazine, Nov. 1977). Occasional 6502 code
is interspersed throughout RENUM for even greater code
efficiency.
RENUM scans the entire program from beginning to end
twice. During pass 1 a line number table is built containing
all line numbers of the program found to be within the re¬
number range. This table begins at the address specified
Number 23
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
107
by the BASIC variable pointer, PV, and is limited in length
by the program pointer, PP. Each entry is two bytes long.
A memory full error occurs if not enough free memory is
available for the table.
As line numbers are entered in the table corresponding
new line numbers are generated and both new and old are
displayed. Should the new line numbers result in an ‘out of
ascending sequence’ condition, then a range error occurs
and renumbering is terminated. It is assumed that the line
numbers of the original program are in ascending sequence.
The purpose of pass 2 is to scan the entire BASIC program
while updating all references of line numbers found in the
table to new assignments. Aside from the line numbers them¬
selves, the line number references sought are identified as
constants immediately preceded by one of the following
tokens:
GOTO
GOSUB
THEN lno
LIST
LIST ,
No other statement normally permitted within an APPLE-II
BASIC program may contain a line number reference. No
errors will occur during pass 2. Exceptions such as empty line
number table and null program are properly considered by
both passes of RENUM.
Append — Theory of Operation
When APPEND is called, the user program with larger line
numbers will be in memory and the one with smaller line
numbers will be read off tape. The current program resides
between two pointers, PP and HIMEM. HIMEM is preserved
and set to the value contained in PP. This ‘hides’ the original
program and prepares to load a new one immediately above
it in memory.
The BASIC load subroutine is called and a normal memory
full error condition will result if not enough free memory is
available to contain both programs. If this error occurs then
the original program will still be hidden. Fortunately, it can
be recovered by calling the tail end of APPEND at $3CD
which simply restores HIMEM. If the load is successful then
HIMEM is restored to its original value and both programs
will be joined. No line number overlap check is performed.
Original Program After Load HIMEM Restored
PP-—
PP-#-
Prog ft 1
Prog ft
PP——
HIMEM-#-
Prog ft 2
Prog ft2
Prog ft:
(hidden)
HIMEM—►
HIMEM-
P
W
•J
a
s
<
X
w
os
w
CQ
2
W
os
o
P
r-
C/3
O
>0
HD
O
iH
in
vO
in
in
o
O
O
r-H
CM
nO
in
CM
yO
CM
lO
2
o
P
in
'O
1
in
CM
vO
in
in
to
O'
in
CM
y£)
in
o o
Q
CM
in
Q
CM
Q
CM
X
o
in
CM
rO
o m
O
Q
CM
o
o
o
*
rH >,
Q
CM
in
r—1 H O
2
X
o
2
X
2
X
o
vO
o
rH ,Q
o
Q
CM
r-H
2
s
mm
to
CO
*-»
1
2
X
o
If) P
O
o
o
o
O
o
r>
mm
II
—A
_
O T3
2
X
CD cd >»
m
in
o
o
o
o
—
—
CQ
a
f—
O CD
o
o
c .Q
—
—
—
—
—
—
—
o
D
H
p
2
o
rH O
—
—
in
in
•H +J
'O
H
in
in 2
2
2
2
2 or.
X
H
cd
h k T3
*
*
*
*
*
r- O
O
o
o
o
o
o
a
*-• to
(0
to
(0
to o
OS
(0
O
w a
*
*
*
*
ctf CD
OJ
n
in
v£>
CO
O'
in
yO
CO
O'
CD
CD
j s
as
or.
or
a? u.
a
2
CD
CD C/3
CM
CD
<T
in
^ P O
mm
mm
mm
mm
—.
C
<d w a
& a
to
X
a
to
X
to
X
to
X
to
X
to
X
a
J A
J 1
A
1
A
1
A
1
A
1
H —
in
CM
CD
4
50
09
70
80
00
06
o
o
CM
O
CD
•H O
r-H rH
a
to
X
to
X
a
E O C/3
o
o
o
o
O
o
o
o
< o n
r^-
O'
o
M
mm
mm
— CM
CM
CM
CM
o
o
o
o
P P
a
CL
a
a
a
a
0.
a
o o
o
o
o
mm
J
U
a
a
a
a
c
A
A
A
A
A
A
A
A —
mm
mm
mm
A
CD
A
A
A
A
CD
OS
e
p
C
CD
PS
u
o
2 O
10 -
X -
n h '
O O O'
o — to o
II —
m tc »-• h
O n H H 2 H O
pm inX2222X-fXH
oot*. — fototouitooxtoo
oidh joiSficJgu.a.zcj
I— — (\]ro<ronr'-oooooo
to o o o o — o — w m
— — — — — — CMCMCMCM
J
A
Page 6
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
108
>CALL 76B APPLE-1 I SASIC RENUMBER/APPEND SUBROUTINES
CO
l«J
2
f-
p
o
x
CD
p
CO
Q
2
x
0.
0.
<t
V
x
W
00
S
p
2
s
»-
y
•
CO
CD
uj
•
o
•
y
m
•
X
•
2
©
y
•
n
CD
X
•
o
y
X
<T
2
Id
/-V
to
2
»»
U)
X
•
X
2
•
o
X
a
r
•
•
to
Id
•
O
—
H
UJ
X
X
X
H
X
2
©
X
X
<t
X
X
X
2
H
us
Id
X
o
•
<t
•
£
•
•
X
Id
id
X
X
*■*
2
y
X
X
X
J
©
p
£
H
y
a
a
D
• •
J
a
•
yC
<o
o
2
J
X
tn
•
•
p
2
2
D
X
J
-4
2
2
• o
CD
2
UJ
—
—•
a
o
*-«
J
J
Id
p
y
•
X
£
-J
•
UJ
2
CD
X
X
M
*—i
O 2
<E
a
>
0.
O
p
<t
CO
X
X
CQ
p
X
X
UJ
y
H
•
o
•
2 J
H
o
10
•
CO
•
X
X
u.
Id
H
X
D
u
J
L>
X
10
J
CD
©
o
ID
J
o
£
X
X
id
o
*-•
O
a
2
D
to
u
<
2
X
O
X
o
U)
o
O
>
O
o
•
•
X
x
X
UJ
X
o
X
£
u
2
<
UJ
to
<*
H
o
X
Id
2
X
X
2
X
X
X
> Id
2
X
•
•
O
X
Q
UJ
Q
*■«
X
<
Id
Id
<c
o
y
y
o
-J
J
J
X
a.
X
UJ 2
J
X
o
<t
2
Q
X
a
X
X
CL
>
£
Q
X
-J
y
D
*>
•-»
o
o
ro
m
X
X
2 •
•
0
~J
r
o
or
o
—*
UJ
O
2
2
*>
o
«
•—
<t
o
o
•-
o
CVJ
cvj
o
1
o
1
o
o
o
L>
O
o
o
H
X
y
•-<
J
J
2
y
y
H
£
H
to
X
*-«
M
H
i
M
i
»-•
*-•
M
*■*
fd
X
Cd
J
CO
<t
Id
<
to
•J
f- o
CO
to
M
H
CO
>
X
>
X
to
CO
CO
CO
CO
CO
CO
UJ
X
<c
UJ
>
5 »
>
o
to
o
X
£
X
CO
<c
X —
CO
to
o
o
2
o
o
<t
«
<t
<C
<t
>
<t
X
Sc
Id
UJ
o
M
2
<r
2
o
L>
<
X X
<r
<t
to
CO
O
J
-J
m
ra
rn
aj
(TJ
©
CO
CO
u
o
CO
2
2
j
X
-J
0 .
J
CO
X
CO
X
2 X
X
X
<
<r
o
o
*
* * *
*
*
to
a
•
*
CD
aj
CD
X
O Id Q
1-
o
*
to
tO
00
O
Q
co cr uj
<t
<t
UJ
ro
_)
^ 2
«
UJ
<0
o
< O n
CO
td
O
oda
*
0.
CO
*
CVJ
o
y j
K <
♦
«
h
<r
o —
<T
O O UJ
UJ
td
X
XXX
a
o —
tO w
CVJ
ro
to o
K-
CD
to O
CK
<x
co o
o
o
—t
♦
CO <
UJ
w
to
f-
VO X
*
*
<t
2
X
%
yC
z o;
- td
*
o
•
*
nj q
*-«
UJ
J
c
UJ UJ
\ t~
*
UJ
K) Is)
N)
KJ
KJ
KJ KJ p
r>
D
r>
p p p
KJ KJ
KJ
KJ
KJ
KJ KJ
KJ
KJ
KJ KJ
KJ
KJ
KJ KJ
K)
KJ
KJ
KJ
KJ
♦
CQ
- D
*
X X
X
X
X
x x a
a
Cf
c?
a cn a
H
X X
X
X
X
X X
X
X
X X
X
X
x a
0.
X
X
X
X
•J
X
*
D
O
p
X
C3
id
2
X £
2 D
— X
£
*
*
CVJ
Id UJ UJ
Id
UJ
UJ Id Id
UJ
UJ
id
Id Id tu
Id
Id X
X
X
X
X X
X
X
X X
X
X
X X
X
X
X
X
X
X
*
» X
X
M
o
m
UJ
UJ 2
o
*
<
*
UJ'UJ
CD
Id 2
2
X UJ
o
*
•
*
J <D
r»
X
M
UJ
UJ
X
♦
*
'X 2
to
o
©
Id
KJ UJ
*
~J
.J
X
J
X
H —
CVJ
w
*
X D
>
2
2
CO X
o 3
*
H
•J
X
H
> o
X x
X
X
00
X
J
<* 2
UJ
UJ
<
<C
D O
> x
*
H
£
D
o
Id
i-
H
02^
H Q
£
Q
Q
2 2
a
a
f-
id
2
2
X
X
X
X
*
m
-J
X
UJ
X
Id
©
Q
«Oph
m
J
_4
o
*-4
CO 2
CO £ O
2
2
-J J
2
2
o
4
X
00
X
<t
*
n
J X
—
£dJ£
a
7
— OP
p o >
>
J
X
J J J X
Id X
to
o > >
©
X
X
a
H
*
CO
o o
-•
—
00
X > UJ
X
<
o
r» or o
CO
UlilUZ
2
flO IQ
CD
O
£ (_> X
X
X X
co
X x
X
o
*
*
«
# *
* # <
#
X X
X
X
X
X X £
X
X
J 1/1 U L)
<t 2
2
-J
J
f- H
1-
to
X CO
X
X
2 2
H
x u
o
£
o-cjn^m^Kcooo
— CO ©
<T
to
CD
<>
O
— CM
©
tn »o mo
o
o
— CM
CD
<y
to
'O
CO
CK O
— CM
©
«T
in
tO
r-
CD
CVJ CVJ CM
CM
CM
CM
CM
CM
CM
©
© ©
©
©
© © © ©
©
*
<r
<*
<y
cr
<7
<T lO
co in
m
in
in
in
m
in
2
b)
X o
H in
O
h
O
©
X
in
00
o
<r
©
p
II
00
M
o:
ra
X
f“*
©
O
D
h-
h
2
H
o
o
H
CO
CO
£
£ £
£
£ X
X
f-
w
X
O
O
X
M
X
X
X o
X
X
o
J
X
O
in
o
in
o
m
O
in
O
O
©
»— •
_J
or.
X
X X
X
2
©
a
©
©
<T
m
in
O
nD
X
o
m
O
in
A
A
A
A
A
A
A
A
A
h
o
in
o
in
o
in o
in
o
in
o
<
<r
—
—
CM
CM
1
i
1
1
1
1
1
1
1
CO
00
CM
CM
©
© c
<T
in in
o
o
X
2
A
A
A
A
o
o
O
O
o
o
O
o
o
M
w
M
1
1
1
1
m
vO
r»
00
o
o
00
CM
©
J
©
—
CM
©
<T
—
—
—
—
—
CM
CM
CM
CM
A
Q
W
a
a
<
x
o
x
X
f—
X
X
<t
H
£
o
X
£
X
<t
X
X
©
£
o
<c
X
o
X
£
J
<t
<
X
2
©
o
©
X
»—<
X
X
o
©
*-«
Id
X
X
f—
H
£ s E 'O ££££££
X ro X in U1 X X X X Id
XXX o x x x x x x
f- O O O J
CO O O O J
— — c\» © <t
J o
A A
h- o o o o o o
CO — CVJ CD O O O
*-* — CVJ rD
J
A
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 7
109
2
«
ft)
•
•«
O
Ul B
o
l)
10
X
in
r
• ft
to
2
m 3
to
10
U
to
X o
2
J to
< 10
X
® >
X
in
X
in
2 •
Ul J
•
CO 2
H
H
2 O
X
CJ
<
— ft)
o y
—
H —
H
— J
•
•
H
to
X
X
2 IJ
ft)
2
2
O O
>
O'
X
to
to
— 2
J
N 2
2 2
H Ul
O'
X
J
o
<r
•
r in
H
>
<*
J
o
X 2
fj
Ul
J
2
i?
Ul
«
UJ o
X
U
X O
X
2
Ul
D •
X o.
CJ
•
J H
U)
2
Q in
2 —
J
2 v
(J
Ul
2
X 2
R
2
2
(J
H •
o
X
2
M
• o
to
o
X
X
V
Ul
Q U)
H X
2
<r —
O
Ul
CJ X ft)
• Q
X O
2
p
X D
X
H
2 2
cn uj
J
H 2
X
H
J 2 J X Q
2 J
2 U J (T o: w I U 2
- 2 t n • X • X ..J2
-52 J
araJOuiHOHO-:*
2 (.) J J X 2 2 2 2 X Id
<2— — <f 2
» 5- x ft; x x
I ~ _ 0. X —
3 « O 2 £ O
• O LI D J
O 2 J 2 O
« — or u
« — 0. X 0. u u
) O I- — 2 >
n>o CD s Jod
H Q < O Q to
h 2 O J U CO
0 2 JhOOX
2 u) o C x
jxr.HXwjo
h J X o <t d u
u. iu o y
- 2 j x
— h h x <f
CJ <X 0 2
CJ * Q
d <d io or
CO - D f J O
• 2 < co Ul
•2 CJ 2 2 %
' (J X * O 2
It- o o o Jo
— I- - JO
a. «
> o * ■ — or
' — o a * a h
) to CJ to — to
<c X x x
ca o — to
- o 5
2 2 2 O —
J — J J to
^ > > in
IJ IJ IJ U) <t
2 2 2 2 0-
J — —
D 2 2
L. J J K
x :» ?• x
(J (J U) Ul
2 2 2 0:
Q JXo2X2XXtro
HQHr'X2HZHZ2X2
w<tw 2 uaiXTC*)M ocn
5 0 ftl W X H ftl % «
' «* x x a x x :» — — o —
s%Q Q 2 2 H Q O 2 222
3<2IM2C5JW2 J J J — 2
'ruui2(3i>:Q
:xxioxdjffliDioid tijuiui
30XXQX»0HHZ2#2Z2
ft) N M
X X a
Q — Q 2 O
ftl X Ql X O
2XQOXQ20IO Uh
OQ 2 WQ 2 OW 0 to to
•— Q
h ^ ? K 9 HO Q 0) Q CO K) 0. QhhUQX- KUKUKQ K ft! Hft!
!jioto C ^?\m :2C ^Jrt C t , ^^ t ^ a ' C ^2 , "9 :DC>C1 “ >2oQt ” ultl,0:Qo * :Qa:2D -3 uD S oQ0 ' Mtl J(XtJ2O
JtOtOJoCD — JlOJiOJlOOJ<tlOjtnn3JtOCDajlOlOtOOJQCQJoCQumQJCQQJoCQtOOCna3Q
a.
(T) IO
D to «t
IO <t C\J
°‘5£!5!£2~-~- ,/>,or '“* >0 ' 0 "" <v,n ** n,0 ** eo<>0 — Ck,f ' , **o<OH» 0‘0 — ftir>fl>m»ftr**ccoo — fti«o.e
, — ronooco'^^^^^^^^inintOiomtntomiOiO'OvO'O'O'OOO'O'O'Or'^f^^r^K^r-r^^.oocotDQOM
UNBIQ-WOUOUUON
n«tooQoo«jo^(jQo
o<ym>or'~®<CQuiXft)ro<r
tototoiotototntoiAtO'O^o
ortoonononoonn
OOOOOOOOOOOOO
% cno, ° ° Ob. ft) O CJ OX X b. to X —
J. 2 2 £ 5? £ rt £ S !C! 2 T. ° “2 08 s n m o r-r~ o r. m o K o <o r- w <m <t oi i~ r- v> c- I~ m « o o ■o eo q
“ ""CMQOlJifinftinW" (M^OOIDIOOCDOUWN-- ^ i. n <f ft n i. ^ i*i i. ty q fi » q ft n i.
'^^ t £9H!Er" CV, C?^' 0 ' 0 r ***00'<®OUlU.OCJr)«rt005 O <t CO Q LI h. - (\l 4 V) « » (M ffi Q O ^ n J)
*C Kr-NN^NSf-tOBOCOfflCO cotooocococooaoooo.oooo<t<t<t<t
r* ooooSooooooo — S3 2 2 2 2 S3 S3 2 (2 2 C? 2 2 2 •? 2 *2 «2 «2 <!> <? o w <•> r> n r> r> o <*> n n n
14
a
<
X
H
2
bl
H
2
J
H
H
a
7.
bl
2
O CD
< •
UJ
i
—
H H
2
0*2
cr:
a
bl
o
PTR
AND
—
0. w UJ
D h- X
a
o •
a
• <x
hi
2
CO
2
A X
O X
X
z
>
< o • ~ ?. e
tTQh* UJ Cl) cr
o CL UJ CJ X x o
it D2 X-OOl*.
O O H H
X or. o h o w
O O UJ 2 I- UJ
-*u.&!rot:ujv)cr
h U] x
CO 2 - O
HJOOHOOH
M W U) M « <t
oQwwiiiwwc:
3 J<0<t«0
o CD CQ IO CQ CD lO
E
(J co
2 CO
K z <t
H • ft.
X X R
O a bl
012 2
0-0 x O
X J X Q Q
ft. CO 0. 2
H 0 2
O Q tr Ul
— 02 ft. X
CO H <t H
< U.
03 —
• * AO
(J * l u
J # • Q
: o
1 <* J o 2
: • H Q 2 —
• O O J
— o o ~
• a 2 a —
: j cm j —
► o o o ft:
i f“ O ifl %
H >0 HO
i o 2 or
o Q • — w
. a * or
• < ♦ o.
CO o to o — —
<t O - O J X X
0 0^0222
«a to <r j j j
« X > — XX
i H O O * 2 ot * Q o
X X
Q X X Q
2 O Q 2 a
O o H ♦ 2
(jOHUHXJhlDtOJ
XJQ<D®D--QO — >
OOXtAOtAO — — d(C>W
KCa tUt,UdEO.uW2
- O Q
I O or CO X 2 « H Q HQ. ft. X XX O OKOXO»JQz4XX<tX*X<XXKX
fJXU)3HHOHt0U)QHU)OHHOHHOHHQft.OH02Xo0QHOX2ft.22HHQOt0Ot0Ot0Oat0t0tnQ
JO"ft»OtOt/>aX-5tOJt/ltOft.t/>tOJtOiOft.«OinJOCOtoJ — uUJiwjolDUffllDWXJJ’JJ-Jj^JJTJlJ
X
a
cooanoQOQo
MMMNNMMM
aQ.CLa.o.a.a.a
UUUUKOUlbJU)
OJ
X 2
Q 2 O
3 JO 2 O
D If S P) (J W (C
CtlJhlJ-XMO
HOWCCHJW
oo-wncrin'OH
Ift'ftvO'ftO'O'fi'O'O
m ® x
D 2
x M a
i
as
d-BOO-N
X x >o r*-
<t -
o-wo<TifioMDOO-wn«rft-fir>©0'0-
o^tnvo^tcoo — «Mrj«rtnor*eoao — wr)«rioo^wo*OOoooooooo — — — — — — — — — — MtM
r^r^r^r~^r'^coeooocoeoeo®eococooo<>0'<AOc>OtOa — — — — — — — — — — — — — — — — — — — w— —
S u. h.OO Ul b. b. Ultlt
— O O' O Ul O ® <t <M O — OC0 QQ(i)QN«Q)|i|O
w ® <7 o <T n CM O O OO — <tuifflu — — — ®®
• OOOOCOOWWWO'OtOtO — flt>O»H0>Ott>r><«OHr»<<*»<<*)M«CMH«Oi0'6O»O0'Otf>*>OOOtt
X (Mfflnr)ltO(M-«£)n-OOP)MnOUOnNQOOOIMQOM<0«QOQOONO<<W<N<W<<NWOIN
<
o on<nn«oNBtauiiton«nflBMD»<t(DODLio-wn<f^MO(MCDQijocj( , )««ioDQONinN»uLN
to oooooooooo------«------NNN«oifliWNNN(MWNnr)nnnrtnn<f^ccMtrMin
•• noooncoortooonoooooMoortooonofooonOfooooowoooortnwnoortoooo
CA OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Page 8
110
Dr. Dobb's Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, CA 94025
Number 23
o
o
<T
IV
4
10
U)
2
D
O
x
ra
o
10
O
>o
o
CM
lO
o
o
n
o
eo
<o
o
o
2
K
0.
<
V
X
(0
£Q in
r o>
o —
2 O
y o
o
o —
— o
to r-
J O
0. O
ft.
<
o
in
o
in
<
o
CM
O
00
<T
o
«o
o
n
o
cm
o
n
n
©
o o
O ID
o o
o
00
O M <0 9 N N
<T O O OJ r> <y
©
O O
O O O O
o — r>
0 0-7
o-
o o o
o — <o m
•o r*- co —
o o o o
— — <•> M CM
o o o r» o
cm o — o —
o o o o o
«o — — cm m> r-
«o io w w w m
o o o o o o
co o to oj m —
— © O' M 00 00
— o o — — —
O O O O o o
Or^coMc'ono — c'jr-or-c'jocvjco —
r^oooco — —<rr-r>-r^oo,r-r--ono>owoococo<roo
_ — — — --— oo — — oocm — o — — ooo — — —
oooooooooooooooooooooooooo
<o — r-OJM — or>oooo«of~<roo
OOCMOO — COOOCOO — — — COCMOO
— — — OCM — OO — O — — — — — — —
ooooooooooooooooo
in cm o
o - o
CM CM CM
o o o
MO O
o — o
CM CM CM
o o o
r*» o cm o
00 O CD CM
O CM — —
o o o o
r- M)
o m
o o
00 — CM O OO *0 «©
oo o r- o o o
O O CM — — o o
o o o o o o o
</nm to
O' m m oo
O — — —
o o o o
«T hO-rf)CMO
oocoot'-'or*
— O O OJ — — o
o o o o o o o
oo M CO <c CM O
CO in CD M 00 to
o — o — o —
o o o o o o
» m n
m m o
o o o
!^m5^^mSRy!? 0 ' u ? C5D ‘ ,r,lt ® u,uw ® u ’* t:jwr, ' Wuu '0 < ^ cl<> ^ NU “ 0r ''OQ®U(DO<coO'UiTiDO'^/)'oajinQ^inc\J
JOfOOOOOOfOujOOQCDMOeOOOOO'OmOOOOOOrom'O'O — «00 — OOOOOO — — 0*0000m0000‘000000000c*t0p'
J2!!? 0 92C2 oQQor,00<noo00f,,0000 ooor)ooc->or>oinoooooooootjor)Of>>oooroo»oooooooroon
• OOOOOOOU.U.OOOOOOOOU.UJOOOOOOOOOOOOOOUIOOOOOOOOOUJOOOOOOOOOU.OOOOOOOOO
a
Q ^ CM f- 2 JO— » XXX
20 mm H O Z > D 22202 — CM OQQO
WHOtff-HHOUIOWZZH^OQU.atil — JJjJ in in UI222 XJ
O0.XXX22DO2»-ZUJU)CnXJ<fzSQ>>>»Q<fflO<(ncnJQoOOJXJ — — t
OaXIIOOOcOOMtH«220li)UOUlliJ(illiJJ - — — WCCQ.CKO’ltrbOO — — *
<4OOOOUl)OQ(3XXMjjDj££i;2Z2ZO0.EU>.2ui.(l.Q.Q.|li0.P.Lfi;(Cli;i£(
- cm H
0 2 XXX U1
X cnoZQQQH H
pXXeooo<tO'0—222 t/ >* <*
■^-:XXXXO.K-JJJ.JJu<Moa
•;h>mai®cDn x oan.
.f- O D O
o
J
o cr.
»- o
O u.
o
X
in o
— o
u.
•n *
-* o
2 J
M
X 2
O 10
I- X
o
2
J
cr
o
u.
X
o
o
J
o
2
J
2
a
J
o
w
»- n
in o-
u. <r
- z
z
o o
h
u) in
Q —
o J
z
x
t- o
U)
cn
o
2
J
X X
o o
U. f 0
X
u o
o
O td
Z H
X Q
<t 0.
Id D
J
E
U]
o
in
«f
CQ
»-
X
bl
2
X
o
to
X
o
H 2 2 H ^ h ^ W Z
02UWZ 0<*tn<nZ0©U)
-OXXO OCM — — OOOH
Cuhhu <ta.JJO<tZ —
cc i-ce a h co z o
UNuawOMUD2DHX
q is i/iu ui QfflininfQininm
2 2
O O
o o
in o mo 0 o-cMnMin'Of'B
CO CO CO CO CO OO'O'OO'O'O'OO'
o o
o o
u. <r O' <t M — —
O CM O CQ r- o Q
Q <0 Q Q O O'OQQO'OO —
u.o — oo u.o — ajoajoo
o
r
in
Cd
0.
<
to o* :
z z
Si! 2
a
XX 2
O I-
t— o
in m
to
o 2
J ^
O D
►“
to
cr.
o X
— * o
in c_> X Z
<f — X O w
m > o in r
in in • x
- a
l X t— 0.
ojcnuiot-
J *j in D. in
■» O' (
O' X <
cr u c
o in i
H o
Id Q
in j
o o
Q M> X Z x
< - U U] o
o>w i in
• J in • x •
a
azxxa Q 2 in
t-t-wwoot-f-f-
in IT 1-3 0.J ifl C K
t- Q
2
ft) 10
D 0.
in a
<
> — cMDMin'OP-eoO'O — (\i n
>000000000 — — — — — .
icmcmcmcmcmcmcmcmcmcmcmcmcmcm:
) o
. o
o
o
«t
o
joocooo ooooocoooc
J — OO — 'OP^OCMCMUCMr-O.
<0^000 U.OCtlin<OCOO><(
<tm® ®m®oo
orjrjno cnr>nnoor>r>
ooooo oooooooo
r> uh.NncMDO"tQo-(\in<t #
in 'TjnOOOOOOOOOQQQQO*
- oooooocoooonrjmoo*
O' OOOOOOOOOOOOOOO *
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 9
111
STRUBAL: A STRUCTURED BASIC COMPILER
Gentlepeople: Received: 78 Jan 25
This letter was inspired by the letter of Neils Laughlin in
your issue No. 19 page 19. Mr. Laughlin is describing a pro¬
posed structured language for microcomputer use. I agree that
the structures proposed by Djikstra and others (DO WHILE,
IF-THEN-ELSE, etc.) are good for writing readable programs,
yet I look at the sample listing on page 20 and it is far from
readable. It took several minutes of reading to figure out what
the program was doing. I feel that computer languages should
not demand such effort from the reader. To show what I feel
a good microcomputer language should look like, I enclosed a
listing of the same program, coded in my partner (Jack
Hemenway) and my new language: STRUBAL. (STRUctured
BAsic Language™) This langauge is implemented as a full
compiler which runs on 6800 processors with 16K of memory.
The compiler is written in 6800 assembler language and is pre¬
sently running on a SWTP system with ICOM floppies,
although STRUBAL has also run from a dual cassette system.
The compiler runs in three passes. Pass one converts the source
language input file into an equivalent assembly-language out¬
put file. Passes two and three are an extended 6800 assembler.
The use of assembly langauge as the intermediate file allows
the programmer to easily read the intermediate file, to opti¬
mize it if desired, and to intersperse his own assembly-language
statements wherever desired. This “inline” or “crutch-code”
facility gives the programmer great power. STRUBAL itself is
a very powerful langauge. There are three data types sup¬
ported: integer (16-bit), floating-point (10 digit BCD), and
character string (bytes). Full math support is provided in
several run-time packages, (trigonometry, logarithms, etc.)
String functions in the language include string comparisons,
string concatenation, variable-length strings, string-to-value and
value-to-string conversion, etc. STRUBAL code is fully relocat¬
able and separately compiled program modules may be linked
to form a single program. Common data areas, external refer¬
ences, etc. are all handled by a relocating loader which is part
of the system. Subroutine calls with named parameters are
supported. Sequential and random disk file access is sup¬
ported. (Tapes have only sequential files, obviously.)
STRUBAL has all of the structured-programming forms
(WHILE, IF-THEN-ELSE, CASE, etc.), plus other forms taken
from BASIC and FORTRAN. (IF-statement, GOTO, GOSUB,
FOR-NEXT, CALL, etc.) PEEK and POKE are provided, as is
a function to return the address of a variable or label. Any
data type may be an array of one or two dimensions. Exten¬
sive I/O format capability is provided for either console or disk
(tape) file I/O. No line numbers are used, since a full editor is
available to build source files and only those lines requiring
transfer labels need have labels—and the labels are alphanu¬
meric names, not hard-to-follow numbers.
That was a quick survey of STRUBAL. It is a fast compiler
... the sample program was fully compiled (3 passes) in less
than four minutes. The assembler part of the package can as¬
semble the entire compiler in about 12 minutes, (on floppies)
Much of this speed comes from a hash-coded symbol table and
a binary-searched keyword table. Keywords are searched on
their first three characters, symbols are searched on the first
six characters.
Let me make a few notes on the STRUBAL program listing.
All lines with an asterisk in the first column are comments and
will also appear in the assembly intermediate file. All
STRUBAL functions are indicated by a dot. .RAND returns a
pseudo-random 16-bit value. Slashes in I/O statements gene¬
rate carriage retum/linefeeds. A percent sign indicates string
I/O. STRUBAL does not require the indentation for blocks; it
was done for readability. The top line is the command to the
MACROFLOPPY tm AT S695
News Release Received: 78 Jan 5
A new series of fully packaged and assembled disk drives
priced as low as $695 — including software, S-100 compatible
controller and 143,000 byte capacity — has been announced
by Micropolis Corporation. Developed for the retail microcom¬
puter market, the new MacroFloppy tm series initially includes
two versions:
Model 1041 packages a drive, enclosure, cabling and con¬
nectors, disk operating system and disk extended BASIC at a
suggested retail price of $695. It is intended for integration
into any 8080A or Z-80 microcomputer chassis.
Model 1042, suggested retail of $795, adds a power supply
and DC regulators for desktop use.
Delivery is 30 days on both models, and they are factory
warranted for 90 days.
Both systems come with complete file protect and built in
ROM bootstrap. MacroFloppys are hard-sectored into 16
sectors each 256 bytes long; total tracks per surface is 35.
Both offer transfer rates of 250K bits/second at an average
rotational latency time of 100 msec. Access time track to
track is 30 msec, and recording density 5162 bits per inch.
The disk operating system offered with each MacroFloppy
subsystem is a complete package including assembler, file
management routines and utilities to support 8080A and
Z-80 programs. MacroFloppy DOS will function in micro¬
computer systems with at least 16K of main memory. The
company’s disk extended BASIC requires 24K of main
storage. Contact Micropolis Corporation, 7959 Deering Ave,
Canoga Park, CA 91304, (213) 703 -1121.
ICOM disk system to print the file “&GUSS” from disk one.
Since STRUBAL is a full compiler, all debugging tools used
in assembler programming can be used with it. STRUBAL
assumes some system monitor (like MIKBUG), but any reason¬
able monitor can be patched in. It is fully debugged and opera¬
tional now.
Enough sales-pitch for now. We hope to market STRUBAL
soon, and will be selling full source listings. STRUBAL is a lot
more complex than a “tiny BASIC”, but I feel it returns a lot
of power for the investment.
Sincerely yours,
Robert D. Grappel
148 Wood Street
Lexington, MA 02173
PRINT,AGUSS*1
* NUMBER-GUESS PROGRAM IN STRUBAL LANGUAGE
* ILLUSTRATES STRUCTURED-PROGRAMMING
* NOTEi RNDNO LIMITED TO RANGE I-IOO
*
INI EGER RNDNO.NGUESS,GUESS
DSiRING YES.GSTAT
*
SIRING YES='Y'
SIRING GSTAT-YES
*
rtHILE GSiAf .EQ. YES
fiNDNO*. ABS I.RANDI I ) )/22H
NGUESS*I
GUESS*-I
WHILE GUESS .NE. RNDNO
INPUT /."GUESS*".GUESS,/
IF GUESS.LT. RNDNO PRINT ' TfX) LOW"./
IF GUESS.EG.RNDNO PRINT /,'O.K. IN ".NOUFSS./
IF GUESS.GT.RwDNO PRINT " TfX) HIGH',/
NGUESS*NGUESS+I
BLOCK
*
INPIU /."PLAY AGAIN? (Y OR N)".%GSTAT
BLOCK
*
STOP
END
Page 10
112
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park. CA 94025
Number 23
A Z~80 Tracer
Dear Dr. Dobbs, Received: 78 Feb 12
Here is a program which I think will be of some value to
your readers! Since you have never to my knowledge
published a Z-80 program, I thought that I might as well
get things off the ground.
This program is a valuable debugging tool. It will move a
breakpoint through the object program while executing it.
The breakpoint is a restart 070 8 that jumps to a register dump
routine. The dump routine will jump to TRACER after
displaying the registers. TRACER will then restore the object
program op code at the location of the breakpoint. It will
then calcluate the location of the next op code to be executed,
load the first two bytes into the Tracer program, insert a
restart at that location, then restore all the prime registers. It
will then return to the object program where it was
interrupted and execute the restored op code.
The TRACER program uses the DIGITAL GROUP Z-80
operating system register dump routine, but can be used with
any routine to display any type of data desired. The routine
must push all prime registers into the stack located at
002000 8 (the stack cannot be used by the object program).
The TRACER program starts at 006110 8 . Then after storing
the stack pointer it will jump to the dump routine at 006134 g .
The dump routine must jump back into TRACER at 006154 8 .
All inputs and outputs are done in the dump routine.
To use TRACER, load a 377 8 (restart jump to 006110 8 )
at the location where debugging is to begin. Then load B1&B2
in TRACER with the first two bytes of the op code. When the
object program is executed the registers will be displayed
(or any data desired) when the restart is encountered.
All addressing is in split octal mode. This program will
only work on a Z-80 system but will trace 8080 programs
since it is a subset of the Z-80 language.
Sincerely, USAFSS, Box 18627
Arthur W. Cline San Antonio, TX 78243
(512)925-2380
006110 355 163 166 006
006114 355 163 151 006
006120 042 132 006
006123 341
006124 053
006125 061 000 002
006130 345
006131 041 *** ***
006134 303 000 003
006137 041 022 000
006142 071
006143 371
006144 341
006145 321
006146 301
006147 361
006150 061 *** ***
006153 311
006154 026 377
006156 052 314 007
006161 355 163 316 007
006165 061 *** ***
006170 175
006171 137
006172 376 375
006174 312 352 006
006177 376 335
006201 312 352 006
PREDUMP LD(006166),SP
LD(00615l),SP
ID(006132),HL
POP HL
DEC. HL
RETURN LD SP,(002000)
PUSH HL
LD HL,******
JP (LUMP)
LD HL,000022
ADD HL,SP
LD SP,HL
POP HL
POP DE
POP BC
POP AP
LD SP,******
RET
START LD D,377
LD HL,(b2,bl)
LD (sp),SP
LD SP,******
LD A,L
LD E,A
CP 375
JP Z,(IX)
CP 335
JP Z,(IX)
006204 376 313
006206 312 024 007
006211 376 355
006213 174
006214 312 334 006
006217 376 351
006221 312 131 007
006224 001 012 000
006225 000
006230 041 322 007
006233 355 261
006235 257
006236 271
006237 173
006240 302 244 007
006243 173
006244 001 011 000
006247 355 261
006251 257
006252 271
006253 302 014 007
006256 173
006257 001 023 000
0Q6262 355 261
006264 257
006265 271
006266 302 024 007
006271 173
006272 001 023 000
006275 355 261
006277 257
006300 271
006301 302 210 007
006304 173
006305 001 007 000
006310 355 261
006312 257
006313 271
006314 302 112 007
006317 173
006320 001 007 000
006323 355 261
006325 257
006326 271
006327 302 162 007
006332 030 101
006334 001 012 000
006337 041 075 010
006342 355 261
006344 257
006345 271
006346 040 031
006350 030 052
006352 174
006353 001 031 000
006356 041 031 010
006361 355 261
006363 257
006364 271
006365 040 025
006367 173
006370 001 013 000
006373 355 261
006375 257
006376 271
006377 040 023
007001 341
007002 053
007003 345
007004 173
007005 167
007006 043
007007 043
007010 043
007011 043
007012 030 137
007014 341
007015 053
007016 345
007017 173
007020 167
CP 313
JP Z,(2BYTE)
CP 355
LD A,H
JP Z, (ESCAPE)
CP 351
JP Z,(JP(HL))
LD BC,000012
NOP
LD HL,007322
CPIR
XOR A
CP C
LD A,E
JP NZ,(RETTST)
LD A,E
LD BC,000011
CPIR
XOR A
CP CL
JP NZ,(3BXTE)
LD A,E
LD BC,000023
CPIR
XOR A
CP C
JP NZ,(2BYTE)
LD A,E
LD BC,000023
CPIR
XOR A
CP c
JP NZ, (CALLTST)
LD A,E
LD BC,000007
CPIR
XOR A.
CP C
JP NZ,(RSI)
LD A,E
LD BC,000007
CPIR
XOR A
CP C
JP NZ,(JRTST)
JR(IBXTE)
ESCAPE LD BC,000012
LD HL 010075
CPIR
XOR A
CP G
JR NZ,(4BXIE)
JR (2BYTE)
IX LD A,H
LD BC,000031
LD HL,010031
CPIR
XOR A
CP C
JR NZ,(3BXTE)
LD A,E
LD BC,000013
CPIR
XOR A
CP C
JR NZ,(2BYTE)
4BYTE POP HL
DEC HL
PUSH HL
LD A,E
LD (HL),A
INC HL
INC HL
INC HL
INC HL
JR(PREEND)
3BXIE POP HL
DEC HL
PUSH HL
LD A,E
LD(HL) ,A
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
113
007021 043
INC HL
007163
061
374
001
007022
030
005
JR 005
007166
062
172
007
007024
341
2BYTE
POP HL
007171
007025
053
DEC. HL
007172
##*
006
007026
345
PUSH HL
007174
355
173
166
006
007027
173
LD A,E
007200
030
222
007030
167
LD (HL),A
007202
355
173
166
006
007031
043
INC HL
007206
030
254
007032
043
INC HL
007210
173
007033
030
116
JR (007153)
007211
061
374
001
007035
341
1BYTE
POP HL
007214
062
223
007
007036
053
DEC HL
007217
361
007037
345
PUSH HL
007220
061
377
377
007040
173
LD A,E
007223
***
235
007
007041 167
LD (HL),A
007226
355
173
166
006
007042
043
INC HL
007232
303
014
007
007043
030
106
JR (007153)
007235
355
173
166
006
007045
341
CALL
POP HL
007241
303
045
007
007046
053
DEC HL
007244
061
374
001
007047
345
PUSH HL
007247
062
256
007
007050
173
LD A ,E
007252
361
007051 167
LD (HL),A
007253
061
320
007
007052
043
INC HL
007256
***
007053 136
LD E,(HL)
007257
355
173
166
006
007054
043
INC. HI
007263
303
035
006
007055
126
LD D,(HL)
007266
355
173
166
006
007056
353
EX DE.HL
007272
3Q3
143
007
007057
176
LD A,(HL)
00727/5- 355
173
316 007
007060
066
377
LD (HL),377
007301
043
007062
030
071
JR(007155)
007302
176
007064
341
JR
POP HL
007303
062
315
007
007065
053
DEC HL
007306 303
137
006
007066
345
PUSH HL
007311 000
007067
173
LD A,E
007312
000
007070
167
LD (HL),A
007313
000
007071
043
INC. HL
007314
**#
007072
176
LD A,(HL)
007315
***
007073
270
CP B
007316
**#
007074
372
103 007
JP M,007103
007317
**#
007077
043
INC HI
007320 266
007100
205
ADD L
007321 007
007101
030
004
JR (007107)
007103
057
CPL
007104 107
007105 175
007106 220
007107 157
007110 030
007112 341
007113 053
007114 345
007115 173
007116 167
007117 356
007121 074
007122 157
007123 046
007125 371
007126 341
007127 030
007131 341
007132 053
007133 345-
007134 173
007135 167
007136/ 052
007141 030
007143 341
007144 053
007145 345
007146 173
007147 167
007150 341
007151 341
007152 000
007153 176
007154 162
007/155 062
007160 030
007162 173
041
307
000
022
366 001
010
CALMS!
RETTST
END.
314 007
113
LD B,A
LD A,L
SUB B
LD L.JL
JR (007153)
RST POP HI
DEC- HL
PUSH HI
LD A,E
LH (HL) f A
XOR 307
INC A
LD L,A
LD H,000
LD SP,HL
POP HL
JR (007153)
JP(HL) POP HL
DEC HL
PUSH HL
LD A,E
LD (HL),A
LD HL,(001366)
JR(007153)
RET POP HL
DEG HL
PUSH HL
LD A,E
LD (HL),A
POP HL
POP HL
NOP
LD A,(HL)
LD (HL),D
LD (007314),A
JR (END)
JRTST LD A..E
co
a
E-t
HCVJCVjr^rOrnrO^rriO
ir\C H cm c^O
O O O H rH H pH pH pH O
HHH rnroH H H f^ino
pH rnvo
ooooornnrnnno
■^■lAOHCMrn^iA^-VO'-O^DVOVOVOVOVOkOvr)
VOVOVO^OVOVOVOVOVOOpHCNJrO-^-mC^OpHCNJ
OOpHpHpHpHHpHHHHpHpHpHHpHC\JC\JC\J
H
rn
o
o
rH
o
t'-K^N^^OOOOOOOO
H (\J r^H-in^) OOJ^^LA^Oh-O
rnrnrnrOrnrnOOOOOOOO
C\JOsJC\JC\JCMC\JC\JC\JrnH-H-H-H-H-^-H-H-ir>
OrHCsJro^mVOC^OOpHOsjrO-^-irvVOC^-pH
vovovovovovovovororo^vovovovovpvovB
OH C\J r^(\J r^OH (\J
OOOOOOOO^^f^^^ronrOrOrO
OOOOOOOOpHOpHHpHHOJCMCVJCNJO
OpHCsjroH-in'Oc^HOOcvj^i-vo^irv'sdc^O
rnrnr0rnrnrnn-»r0rnOOOOOOOOOO
C\J
CO
rO
O
O
Page 12 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
114
LD SP,001374
LD (00717/2),A
POP AP
JR*(007202)
LD SP, (006166)
JR (2BYTE)
LD SP,(006166)
JR (JR)
LD A,E
LD SP,001374
LD(007223),A
POP AP
LD SP,377377
***007235
LD SP,(006166)
JP (3BYTE)
LD SP,(006166)
JP (CALL)
LD SP,001374
LD (007256),A
POP AP
LD SP,007320
RET *
LD SP,(006166)
JP (lBYTE)
LD SP,(006166)
JP (RET)
LD SP, (007/316)
INC HL
LD A,(HI)
LD(007315),A
JP (RETURN)
NOP
NOP
NOP
B1
B2
SP L
SP H
DUMMY SP L
DUMMY SP H
(0(0(0(0(00
<~OH- lP»^D
C\J C\J CVJ CM CM O
Number 23
A KIM Binary Calculator
BY JOHN EATON
1126 N 2nd
Vincennes, Ind. 47591
Copyright 1977
Binary math has always been a stumbling block for anyone
attempting to study the inner workings of a computer. No
matter how often you work problems in binary, octal or
hexadecimal, you can never work as efficiently as you can in
decimal. Most of us when confronted with a problem involving
other number systems will have to reach for a pencil and paper
in order to obtain a result.
But now there is an easier way to solve binary math
problems. With this software your KIM-1 or other 6502
system can do all the work and give you the result in a form
that you can understand. The program is a machine language
routine that will fit in less than IK of memory. It communi¬
cates with the user through any ASCII I/O device.
The program will work with binary numbers up to 16
bits. They can be inputted to the program in decimal, hexa¬
decimal, octal, binary or as an ASCII literal character. The user
may specify whether the results are displayed in decimal,
hexadecimal, octal or binary. With these features the program
is able to convert numbers between different bases.
Several logic functions are available. The program will
take any two 16 bit numbers and perform the operations
of AND, OR, NOR, EOR and NAND. You may also perform
the arithmetic operations of addition and subtraction. The
inverse and two’s complement of any 16 bit number can be
found.
There are two rotate commands available. The rotate
commands treat two 16 bit numbers as a single 32 bit number
and can shift it left or right up to 16 bits.
Using the Routines
The program requires a MOS 6502 based system and must
have a rotate right instruction. If you have one of the earlier
processors then you will have to modify the code around
address 327E to perform eight ROL’s for each ROR. The pro¬
gram is assembled starting at address 3000 but is small enough
that it will fit in a KIM-1 without any additional memory.
The starting addresses for the user’s I/O routines go in the
first 9 bytes. You will need a single character input routine,
single character output routine and a routine that performs
a carriage return and linefeed.
Start the program at address 3010. It should respond with
a carriage return and linefeed. The first thing that you should
do is set the display mode. Type either DEC, HEX, OCT, or
BIN depending on what mode you want the result to be
displayed in. The mode that you type will remain in effect
until you specify a new one. The program will respond by
displaying the current value of its display register.
The ENT command is used to enter numbers into the
display register. Type ENT and a space followed by a number.
If the number is other than a decimal number, it must be
preceded by a % for binary, @ for octal, $ for hex and “ for an
ASCII literal. ASCII literals must end with a ”, The number
must be an integer and may be preceded by a ” if the two’s
complement of the number is wanted. Once a number is
displayed by the program you can use it in various ways. If
you type INV or TSC then the inverse or two’s complement of
the number is displayed.
Several operations require the use of a second number to
produce a result. Logical functions are available by typing
AND, OR, EOR, NAND or NOR. Each of these commands
must be followed by a space and a second number. The
number can be in the same format as in the ENT command.
The result of the operation will be displayed. The commands
ADD and SUB may be used in a similar manner for integer
arithmetic.
The rotate commands require a special format. To use them
type ROL or ROR followed by an integer number in paren¬
thesis. This number specifies the number of bits that are to
be shifted. The parenthesis must be immediately followed
by a 16 bit number that is to be shifted into the display
to replace the bits that are shifted out.
The program does all binary/decimal conversions with
counting loops. It’s very easy to write but extremely slow.
The worst case time for any conversion is 5 seconds so if
you want fast results use a non-decimal display mode.
Isn’t it nice to now have a computer that can solve prob¬
lems that you never would have to solve if you didn’t have
a computer?
0000
DISL
Display
0001
jISH
register
0002
JECL
dec/bin conversion
0003
bECH
register
0004
BUFL
Buffer 3 Bytes
0005
BUFH
0006
BUF0
0007
P0IN
input line pointer
0008
MODE
display mode
0009
SHIFT
ft of bits per char
000A
MASK
000B
SIGN
oooc
VEB
000D
VEB+1
n 00E
VEB+2
0010
LR
line register 32 bytes
3000 6C
00
00
INPUT
JMP CHAIN
user input routine
3003 6c
00
00
0TPUT
JMP CHAR0T
user output routine
3006 6C
00
00
GRIP
JMP CARLF
user carret/lf routine
3009 EA
NOP
300A 20
03
30
OUT
J SR OTFUT
display number
300D 68
DISPLA
PLA
300E DO
FA
BNE OUT
characters on stack
3010 A9
01
START
LD Arir 01
Start program here******
3012 85
o?
STA POIN
3016 20
06
30
JSR CRLF
3017 C6
07
BACK
DEC POIN
3019 20
00
30
LOOP
JSR INPUT
fetch character in Accum
301C C9
08
CMP#08
backspace?
301E F0
F7
BEQ BACK
yes
3020 A6
07
LbX POIN
3022 95
10
STA LR,X
save character in pg 0
3026 e6
07
INC POIN
3026 C9
ou
CMPtfOD
carriage return?
3028 DO
EF
BNE LOOP
302A 20
06
30
JSR CRLF
302b )&
CL!)
302E A0
04
LDY#06
3030 20
95
30
J SR LOAD
load number into buffer
3033 20
D7
30
JSR OP
perform operation
3036 A2
01
LDXjYOI
3038 35
00
MOVE
LbA JlSL.X
move display register
303A 95
04
STA BUFL,X
into buffer and invert
303 c 69 FF
E0rl#FF
into dec/bin conversion
303E 95
02
STA DECL.X
register
3060 CA
7 EX
3061 10
F5
BPL MOVE
3063 A9
00
L /MOO
3065 85
06
STA BUFD
304? 48
PHA
end of stack storage
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
115
3048 A6
08
LjX MOjE
display mode
3103
20
58 31
SUB
JSR TSCB
304A DO
27
BNE DIS1
non decimal
3106
A9
75
ADD
LDA# 7 5
304C F8
SEj
3108
DO
19
BNE EXEC
304D 20
D9
31
J SR SET9
Buffer=999999
310A
A9
31
NAD
LDA#31
3050 38
DEC1
SEC
add 1 to buffer
310C
48
PHA
3051 A0
02
LDY#02
31OD
A9
13
LDA#13
3053 A2
00
LDX#00
310F
48
PHA
3055 85
04
DEC2
LDA BUFL.X
3110
A9
35
AND
lda#35
3057 69
00
ADC#00
3112
DO
OF
BNE EXEC
3059 95
04
STA BUFL.X
3114
20
DD 31
INV
JSR SETF
305B E8
I NX
3117
A9
55
EOR
LDA#55
305c 88
DEY
3119
DO
08
BNE EXEC
305D 10
F6
BPL DEC2
311B
A9
31
NOR
LDA#31
305F E6
02
INC DECL
add 1 to JECL
311D
48
PHA
3061 DO
ED
BNE DEC1
311E
A9
13
LDA#13
3063 E6
03
DEC 3
INC DECH
3120
48
PHA
3065 F0
06
BEQ DEC4
finished counting
3121
A9
15
ORR
LDA#15
306? 20
6A
32
J SR ADD256
add 256 to buffer
3123
85
oc
EXEC
STA VEB
306A 4C
63
30
JMP DEC3
3125
A9
00
LDA#00
3127
85
OD
STA VEB+1
306D A0
14
DEC4
LDY#14
lenght* 20 bits
3129
A9
60
lda#6o
306F A2
04
LDX#04
bits/char* 4
312B
85
OE
STA VEB+2
3071 DO
03
BNE DIS2
unconditional branch
312D
18
CLC
312E
A2
00
LDX#00
3073 BC
65
32
DIS1
LDY TAB2-1.X
fetch lenght
3130
AO
01
LDY#01
3076 86
09
DIS2
STX SHIFT
3132
B5
04
EXEC1
LDA BUFL.X
3078 D8
CLD
3134
20
OC 00
JSR VEB
3079 A6
09
DIS3
LDX SHIFT
fetch LSD and save on stack
3137
95
00
STA DISL.X
307B A9
80
LDA#80
3139
E8
I NX
307D 20
7E
32
DIS4
JSR ROTATE
313A
88
DEY
3080 88
DEY
313B
10
F5
BPL EXEC1
3081 30
3083 CA
8A
BMI DISPLA
nFY
display all characters
313D
60
RTS
3084 DO
F7
BNE DIS4
313E
A5
04
ENT
LDA BUFL
3086 4A
DIS5
LSR A
char in A,shift to lo end
3140
85
00
STA DISL
3087 DO
FD
BCC DIS5
3142
A5
05
LDA BUFH
3089 C9
OA
CMP#0A
convert to ASCII
3144
85
01
STA DISH
308B 90
02
BCC DIS6
3146
60
RTS
308D 69
06
ADC#06
308F 69
30
DIS6
ADC#30
3147
A9
01
BIN
LDA#01
3091 48
PHA
save char on stack
3149
DO
OA
BNE MOD
3092 4C
79
30
JMP DIS3
314B
AQ
03
OCT
LDA#03
314d
DO
06
BNE MOD
3095 A2
04
LOAD
LDX# 04
number load routine
314f
A9
04
HEX
LDA#04
3097 B9
10
00
L0AD1
LDA LR,Y
Y points to start
3151
DO
02
BNE MOD
309A DD
D2
30
CMP LOAD8,X
match to
3153
A9
00
DEC
LDA#00
309D FO
15
BEQ L0AD4
match found
3155
85
08
MOD
STA MODE
309F CA
DEX
3157
60
RTS
30A0 DO
F5
BNE LOAD1
30A2 A2
04
LDX#04
decimal input
3158
A2
04
TSCB
LuX#04
30A4 20
97
31
JSR LOADT
input number
315A
DO
02
BNE TSC1
30A7 20
E6
31
JSR DECHEX
convert to hex
315C
A2
00
TSC
LDX#00
30AA A5
OB
L0AD2
LDA SIGN
complement if "-"
315E
38
T JC 1
SEC
30AC C9
21:
CMP#"-"
315?
98
TYA
30AE DO
03
BNE LOAD3
3160
48
PHA
30B0 20
58
31
JSR TSCB
3161
AO
01
LDY#01
30B3 60
LOAD 3
RTS
3163
B5
00
TSC 2
LDA DISL.X
30B4 EO
02
LOAD4
CPX#02
test for ASCII literal
3165
49
FF
EOR#FF
30B6 DO
14
BNE L0AD7
3167
69
00
ADC#00
30B8 C8
LOAD 5
I NY
ASCII section
3169
95
00
STA DISL.X
30B9 A2
07
LDX#07
316B
E8
I NX
30BB B9
10
00
LDA LR,Y
316c
88
DEY
30BE C9
22
CMP#"""
last character
3160
10
F4
BPL TSC2
30C0 FO
FI
BEQ LOAD3
316f
68
PLA
30C2 OA
L0AD6
ASL A
shift char into buff
3170
A8
TAY
30C3 26
04
ROL BUFL
3171
60
RTS
30C5 26
05
ROL BUFH
30C7 CA
DEX
3172
20
58 31
ROR
JSR TSCB
30C8 10
P ! 8
BPL LOAD6
3175
A9
IF
LDA# IF
30CA 30
EC
BMI LOAD5
3177
25
04
AND BUFL
30CC C8
LOAD 7
I NY
hex.oct and bin
3179
85
04
STA BUFL
30CD 20
97
31
JSR LOADT
317B
C6
04
ROL
DEC BUFL
30D0 4C
AA
30
JMP L0AD2
317D
A9
3F
LDA# 3F
30D3 25
22
4o
LOAD8+1
.BYTE
317?
25
04
AND BUFL
30D6 24
.BYTE $
3181
48
PHA
3182
C8
INY
30D7 98
OP
TYA
look up command and
3183
20
95 30
JSR LOAD
30C8 48
PHA
perform
3186
68
PLA
30D9 AO
00
LDY#00
3187
AS
TAY
30CB A2
00
LDX#00
3188
A5
01
R0L1
LDA DISH
3ODD 20
FO
30
JSR 0P1
match 1st letter
318A
OA
ASL A
30E0 20
FO
30
JSR 0P1
match 2nd letter
318B
26
04
ROL BUFL
30E3 20
FO
30
JSR 0P1
match 3rd letter
3180
26
05
ROL BUFH
30S6 68
PLA
318f
26
00
ROL DISL
30E? A8
TAY
3191
26
01
ROL DISH
30E8 A9
31
LDA#31
address hi byte
3193
88
DEY
30EA 48
PHA
3194
10
F2
BPL R0L1
30EB B3
16
32
LDA TABl.X
address lo byte-1
3196
60
RTS
30EE 43
PHA
30EF 60
KTS
jump to operation
3197
B9
10 00
LOADT
LDA LR, Y
30F0 BD
16
32
0P1
LDA TABl.X
search table for match
319A
85
OB
STA SIGN
30F3 39
10
00
CMP Lh,Y
319C
C9
2D
CMP#"-"
30F6 FO
08
BEQ 0P2
match found
319E
DO
01
BNE LOADT1
30.-8 E8
I NX
next entry
31A0
C8
INY
30.-9 E8
I NX
31A1
86
09
LOADT1
STX SHIFT
30rA E8
I NX
31A3
BD
DO 31
LDA L0ADT5.X
30FB E8
I NX
31A6
85
OA
STA MASK
30FC C9
FF
CMP#FF
end of table?
31A8
20
D5'31
JSR SETZ
30FE DO
FO
BNE 0P1
31AB
BQ
10 00
L0ADT2
LDA LR, Y
3100 E8
0P2
I NX
31AE
C9
30
CMP#30
3101 C8
I NY
31B0
90
IE
BCC LOADT5
3102 60
RTS
31B2
09
3A
CMP#3A
routines that perform
operations
INV address-1
INV address-1
two's comp of buff
two's comp of display
invert byte
add 1
rotate right by rotating
left 32-n times
set C to bit 7 of DISH
shift registers left
Y times
Load routine for all
but ASCII
test for negative
# of bits per char
buff=000000
ending character
Page 14 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
116
Number 23
TINY BASIC FOR COSMAC
Dear Sir:
I have read letters in vour magazine (and others) seeking a
source of basic for the RCA COSMAC CDP 1802 microproces¬
sor. Infinite Incorporated offers tiny basic 3K on paper tape,
listing or cassette tape. Their address is: Infinite Incorporated,
1924 Waverley Place, Melbourne, FL 32901.
Yours truly,
Dana S. Majors 28 La Cienega Way
Yuba City, CA 95991
WHIZ’ LOADER/DUMPER
news release Received: 77 Dec 12
Shifting Sands Microcomputer Products Corporation has
begun shipping WHIZ, a software program for recording and
loading MC6800 based programs on the SWTPC M68
computer with MIKBUG and the SWTPC AC-30 cassette
interface. WHIZ operates at nine times the standard MIKBUG
format 300 baud speed and three times that of the binary
format. This higher speed capability is provided without any
modifications to the standard computer or AC-30. Load a
IK program in 14 seconds, 4K in 48 seconds, and 8K BASIC
in 85 seconds. WHIZ includes an interactive front-end which
allows the specification of a header and program start address
to be placed on tape for read-back later. For $15.95, WHIZ is
supplied on Kansas City standard cassette in MIKBUG format
and includes a built-in relocater to place your own copy of
WHIZ in RAM memory wherever you wish. WHIZ is
optionally available in 2708 EPROM from Shifting Sands
Microcomputer Products Corporation, Box 441, Fairborn, OH
45324.
DATAFORCE MAINTENANCE SERVICE
FOR COMPUTER VENDORS
News Release Received: 77 Sept 1
A national service organization is seeking the business of
independent vendors of small business computers including
computer stores. The general trouble shooting of machines
in this market has been generally viewed as unprofitable and
the major drawback to handling the bottom end of small
computer lines. But the Dataforce Service Company is now
offering to perform warranty or out of warranty work and
field service for vendors of small computers and computer
kits anywhere in the United States.
Dataforce has 115 service locations in the country and
is expanding with the goal of having a service outlet within
50 miles of every computer sold.
A central diagnostic center is at Dataforce’s headquarters,
2807-F Oregon Court, Torrance, CA 90503. It opens at
5 a.m. for trouble calls from the East Coast and reamins
open until 5 p.m., Monday through Friday. The company
stresses its desire to help first time computer users with the
simple problems arising from unfamiliarity with their equip¬
ment as well as the sophisticated user who needs a highly
skilled diagnosis of a computer problem.
Dataforce is first contacted by calling its Torrance diag¬
nostic center. In California the number is (213) 328-2950.
Outside the state, call (800) 421-1858. A technician qualifies
the nature of the problem and takes the necessary steps to
resolve it. When on-site assistance is needed, Dataforce
dispatches parts and test equipment from the closest service
organization to the trouble.
The company is wholly owned by Randal Data Systems,
Inc., but operates independently. It was created to meet
the requirements of Randal distributors, outlets for the
company’s Link 100, Link 200, and Link 500 series, small
business computers._
31B4 90 06
BCC L0ADT3
number
3207
A5
02
LDA dECL move into buffer
31B6 C9 4?
CMP*4?
ending character
3209
85
04
STA BUFL
31B8 B0 16
BCS L0ADT5
320B
A5
03
LDA DECH
31BA E9 06
SBC#06
320D
85
05
STA BUFH
31BC 25 0A
L0ADT3
AND MASK
clear unneeded bits
320F
A9
00
LDA#00
31BE A6 09
31C0 06 04
LDX SHIFT
3211
85
06
STA BUF0
L0ADT4
ASL BUFL
shift buffer X times
3213
68
PLA
31C2 26 05
R0L BUFH
3214
A8
TAY
31C4 26 06
R0L BUF0
3215
60
RTS
31C6 CA
DEX
31C? DO F?
BNE L0ADT4
3216
41
44
44
05
TAB1 consists of 3 ASCII chars and the
31C9 05 04
ORA BUFL
combine new character
321A
41
4E
44
OF
lo byte-1 of the operations add¬
31CB 85 04
STA BUFL
321E
42
49
4E
46
ress. Hi byte * 31.
31CD C8
INY
3222
44
45
43
52
31CE DO DB
BNE L0ADT2
unconditional
3226
45
4E
54
3D
31D0 60
L0ADT5
RTS
322A
45
4f
52
16
31D1 01 00 0?
.BYTE 01,00,0?
322E
48
45
58
4E
31D4 OF
.BYTE OF
3232
49
4E
56
13
3236
4E
41
44
09
31D5 A9 00
SETZ
LDAtfOO
323A
4E
4F
52
1A
31D? F9 06
BEQ SET
323E
4f
43
54
4a
31D9 A9 99
SET9
LDA#99
3242
4F
4f
52
20
31DB DO 02
BNE SET
3246
52
4C
7A
31DD A9 FF
SETF
LDA#FF
324a
52
4f
52
71
3IDF 85 04
SET
STA BUFL
324E
53
55
42
02
31E1 85 05
STA BUFH
3252
54
53
43
5B
31E3 85 06
STA BUF0
3256
FF
FF
FF
3c
31E5 60
RTS
325A
FF
FF
FF
3c
325E
FF
FF
FF
3C
31E6 98
DECHEX
TYA
decimal to binary conv
3262
FF
FF
FF
30
31E7 48
PHA
3266
10
10
12
10
TAB2+1 consists of lenghts for non dec dis
31E8 F8
SED
31E9 A9 FF
LDA^FF
32 6A
18
ADD256
CLC add 256 to buffer
31EB 85 02
STA DECL
326B
A5
04
LDA BUFL
31ED 85 03
STA DECH
326d
69
56
adc^56
31EF E6 02
DH1
INC DECL
326F
85
04
STA BUFL
31F1 DO 02
BNE DH2
3271
A5
05
LDA BUFH
31F3 E6 03
INC DECH
3273
69
02
ADC#02
31F5 A2 00
DH2
LDX^OO
3275
85
05
STA BUFH
31F? A0 02
LDY#02
3277
A5
06
LDA BUF0
31F9 18
CLC
3279
69
00
ADC#00
31FA B5 04
DH3
LDA BUFL.X
327B
85
06
STA BUF0
31FC E9 00
SBCffOO
327D
60
RTS
31FE 95 04
STA BUFL.X
3200 E8
I NX
327E
46
06
ROTATE
LSR BUF0 perform rotate rights
3201 88
DEY
3280
66
3
R0R BUFH
3202 10 F6
BPL DH3
keep looping until
3282
66
R0R BUFL
3204 B0 E9
BCS DH1
buffer is 0000
3284
6A
R0R A
3206 D8
CLD
3285
60
RTS
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 15
117
Status of the UCSD PASCAL Project
BY KENNETH L. BOWLES
Director IIS
This is a brief report on the current status of the UCSD
PASCAL project intended to answer the questions of the
hundreds of people who have been writing to us or calling by
telephone. It is our intention eventually to reach a steady state
in which we can afford to have full time help capable of
responding to such inquiries. For the present, we have to
apologize once again to those who may have been kept too
long waiting for replies.
Kenneth L. Bowles
Institute for Information Systems
University of California, San Diego
La Jolla, CA 92093 (714) 452-4526
Nature of the Project
The project is one of the principal activities of the Institute
for Information Systems (IIS). Like other “Organized Research
Units”, IIS is operated primarily to provide resources and
activities within which students and faculty can conduct
research and development projects. Within the range of such
activities, projects may support instruction and other public
services though the more usual activities of an ORU involve
only basic research.
Under the IIS we have developed a major software system
for stand-alone microcomputers based on the PASCAL
language. The initial reason for developing the system was to
support instruction activities at UCSD. However, the system
is designed for general purpose use, particularly for the devel¬
opment of interactive software, and for software development
in general. The system has matured sufficiently that we are
distributing copies to outside users at a $200 fee which pays
for some of the student part-time assistants who provide
support to users and maintain the software. Under prevailing
University policies, we are not attempting to recover capital
costs from the fees paid by users of our software package.
However, a number of interested industrial firms have provided
assistance to further the project through unrestricted grants
to the Regents of the University of California marked for use
by our project. These grants are our principal source of oper¬
ating funds at the present time.
Since the PASCAL based software system was developed
with the intent of supporting long term instructional projects,
we have placed very high emphasis on machine independence.
We expect the repertoire of instructional software developed
to use the underlying system to grow very large. The develop¬
ment costs for the instructional software will eventually dwarf
the costs of the hardware on which it operates. Since the
industry is introducing new microcomputer designs at a rapid
rate, we wanted to be able to move the entire software reper¬
toire to new machines with a minimum of effort. As will be
detailed in later sections of this note, our system is now
running on 5 dis-similar processors, with more planned in the
relatively near future. We are using the Digital Equipment
LSI-11 for teaching. Versions for the 8080 and Z80 micro¬
processors are operational and will be ready to distribute on
or about 1 January, 1978.
We intend to continue promoting the use of our PASCAL-
based system on as many popular microprocessors as practical
for two reasons. First, this should provide IIS with a source of
continuing income to pay for student projects. Second,
PASCAL with extensions is a superior language for system
programming, and we believe that it is in the public interest to
assist in the current effort of many people and institutions to
promote wider use of PASCAL in place of some of the earlier
high level languages. Though PASCAL may have some short¬
comings for specific applications when compared to specific
proprietary languages, we regard it as by far the best general
purpose language now in the public domain.
Our current Research and Development interests include:
a. Methods of making large software systems like ours
more readily transportable to new processor architectures.
b. The use of microcomputers as intelligent communica¬
tions devices to assist humans to work together even when
located thousands of miles apart. This interest will eventual¬
ly involve us in a variety of complex software issues. In the
near term it will provide us with an efficient method of
supporting users of our software system who are remote
from UCSD.
c. Joint use of microcomputers and Keller’s Personalized
System of Instruction (PSI) as a means of offering high
quality college level mass education at lower costs per
enrolled student than associated with conventional methods.
A published introductory textbook on problem solving
using PASCAL, and a library of automated quizzes and
record keeping software to go with the textbook, are
available to others as a first step in this direction.
d. Exploration of possibilities and software problems
associated with new hardware devices or architectures
adaptable to the purposes already described. Examples
include video disks, low cost X-Y input devices, and low
cost strategies for interconnecting many semi-independent
microcomputers.
Partly as a matter of self preservation, we have become
interested in the problem of standards for the PASCAL
language. The United States Defense Department and many
large industrial corporations have recently decided to use
PASCAL as a base language which they would extend, and
possibly alter, to create system implementation langauges.
Although almost every organization has chosen to extend or
alter in slightly different ways, we have found that the intent
portrayed in most instances is very similar. In our own imple¬
mentation, we too found it necessary to extend PASCAL, and
in very minor ways to alter the base language as described in
Niklaus Wirth’s widely read “Report”on the langauge (see
Jensen, K. and N. Wirth, PASCAL User Manual and Report,
Springer Verlag, 1975). We, and many others in the PASCAL
User Group, are very much concerned that all this extension
and alteration activity will result in PASCAL going the way of
BASIC for which hundreds of dialects are in common use. We
believe that a chance still exists to gain consensus on a
substantial family of PASCAL extensions for system program¬
ming, provided that this can be brought about within the next
6 to 12 months. Unless someone does so before us, we intend
to convene a summer workshop for representatives of some of
the major using organizations in the hope that such a consensus
can be reached.
Another ancillary activity of the project has been continuing
search for low cost microcomputer hardware of high quality
for use in educational institutions — particularly ours. We have
been advising and collaborating with EDUCOM regarding
establishment of quantity purchase discounts for stand-alone
microcomputers. The first microcomputer to be included in
Page 16
118
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
the EDUCOM discount program is the Terak Corporation
8510A, which is based on the Digital Equipment LSI-11.
For the current market, the Terak unit’s price of $5500 to
EDUCOM member institutions is highly competitive. Never¬
theless, the rate of new announcements from the industry
continues very high, and we believe that it is all but
impossible to predict what hardware will provide the best
cost/performance tradeoff for as long as even one year in
advance. Of necessity, our search has concentrated on stand¬
alone microcomputers with graphic display capabilities, and
with enough main memory and secondary storage to handle
the extensive software and course materials with which we
are working. We welcome inputs on this subject from other
institutions, or from any vendor, and endeavor to keep
EDUCOM informed of opportunities that seem advantageous.
In addition to educational and communications applications,
we are interested in word processing and business applications
of the same machines.
The following sections of this status report contain brief
detailed summaries covering most of the topics just
enumerated. If we haven’t answered your questions yet, please
try again with a phone call or letter. For those who already
have our software system in use, we will soon be providing
an automatic Tele-Mail facility on a dial-in basis. This should
improve dramatically our ability to keep you informed and to
respond when software difficulties arise.
The PASCAL based Software System
Thus far, users who have received our first released system
have copies of version 1.3, which was completed in mid August
this year. We have ourselves been using version I.3c since early
October. By the end of the December academic break, we
hope to have a version 1.4 available for distribution. The most
significant generally useful addition since the 1.3 release has
been the screen-oriented editor. A major package for prepara¬
tion of CAI programs, following the general philosophy of the
University of California Irvine Physics Computer Develop¬
ment Project (PCDP), has been placed in operation on the
Terak 8510A microcomputer. Except for some graphics
materials within this package, it can be used on a wide variety
of CRT screen display devices. Software more specifically
oriented to the Terak machine is also available, and includes
a character set editor (for the soft character generator), and
a bookkeeping package for keeping track of student progress
in a large Keller Plan (TPSI) class.
The software system is currently executed in a pseudo
machine interpreter, which emulates a hypothetical real
machine designed to handle PASCAL constructs efficiently.
Our pseudo machine is similar in concept to the P-machine
distributed by Wirth’s group at Zurich, but we have made
extensive changes to compress the PASCAL object code into
a much smaller space than possible with the Zurich interpreter.
The interpreter, and run-time support routines, currently
occupy about 8K bytes of main memory. The interpreter is
in the native machine language of the host machine, and thus
far has been coded by hand using the host’s assembly language.
All other code in the system is written in extended PASCAL.
While the interpreted object code runs roughly five times
slower than native code for the host machine, several factors
allow our large system programs to run substantially faster
than this would indicate. The strategy of code compression
makes it possible to run relatively large programs without time
consuming overlays. For example, the complete compiler
occupies 20K bytes in a single overlay. Since the system is
designed for frequent compile/go cycles associated with
instruction, we have added several built-in procedures and
functions to handle low level operations needed frequently
by the compiler. As a result, the compiler translates PASCAL
source code at about 650 lines per minute on an LSI-11 with
its clock set to 2.2 MHz. On a 4 MHz Z80, the compile speed
will be slightly faster than this.
Interpreter based versions of our system are now running
on 5 distinct processors, and two others are close to comple¬
tion. Those operating include DEC PDP-1 l’s ranging from the
LSI-11 to the 11/45, using either floppy disks or RK05 disks
for secondary storage. Versions for the 8080 and Z80 are
operating in our laboratory, but more of that later. Sperry
Univac Minicomputer Operations at Irvine is using the system
on the V-75 and related machines. Another group at UCSD
has the system running on the Nanodata QM-1. With support
from General Automation, a version is close to completion on
the GA-440 family of machines. National Semiconductor
has an implementation nearly completed on the PACE micro¬
computer.
The principal modules of the system as it will be distributed
in the 1.4 release include the following:
PASCAL compiler
File manager (capabilities similar to DEC’S PIP)
Screen oriented editor (cursor positioning, immediate
updates)
Line oriented editor (similar to DEC’S RT-11 Editor)
Debugger (single line execution, reference to variable
contents)
SETUP program (adapt system to most ASCII terminals)
BASIC compiler (ANSI standard plus strings)
Operating System and user command interpreter
PASCAL pseudo machine interpreter
Linker program (for linking independently compiled
program segments)
Desk Calculator utility program
Users of the Terak 8510A may, on request, also receive
copies of the CAI package, and automated quizzes for the
introductory textbook, as well as the bookkeeping package.
Documents describing all of the above are available, and
part of the release, but not all documents can be considered
complete at this time. We distribute source and object code
files on separate floppy disks formatted to be compatible with
the IBM 3740 standard, with 512 byte blocks laid out in alter¬
nate 128 bytes sectors according to DEC’S standard. We have
occasionally sent copies recorded directly on disk packs for
the RK05 drives. All other media are painful or impossible
for us to handle, and no promises are made to use them. Those
who order the full $200 release package will be sent both the
documents, and printed lisitings of the source programs.
Copies of the descriptive documents, amounting to
approximately 150 pages, may be ordered at $10 each (checks
payable to the “Regents of the University of California”) to
cover printing and handling costs.
Minimum Configuration
In order to use the compiler, you need a total of at least
48K bytes of main memory, including the 8K bytes assigned
to the interpreter. We use 56K bytes. Ideally, the interpreter
should be completed re-entrant and thus it should be possible
to operate the interpreter from Read Only Memory. To date,
the ideal has not quite been achieved, as none of our sponsors
has yet insisted on that feature.
At present, the system we use with students contains
several built-in functions not needed for system development.
The aggregate size of these functions is large enough to prevent
compiling the compiler itself, or the operating system, even on
a 56K byte system. Accordingly, we currently have two ver¬
sions of the system, one for students, and one for system
development. Within the next few months, we plan to add a
means of configuring general purpose libraries for the system,
and by that means expect to be able to return to a single
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 17
119
version for all purposes. That single version should be practical
to use in less than 48K bytes for some purposes.
If you intend to compile on one microcomputer, and to
execute object routines on others, the others can get by with
as little as 16K bytes of main memory if the operating system
is not used. The resident portion of the operating system
occupies about 8K bytes itself. This will undoubtedly be
reduced as part of the libraries project.
The system is designed to be used with standard IBM
compatible floppy disks. Clearly it can be used with other
varieties of floppy disks, or with other secondary storage
media, with appropriate I/O drivers. The I/O drivers have
proven to be one of our principal bottlenecks, and we make no
promises in advance about supporting other devices. For
DEC PDP-11 machines, the floppy disk drivers are assumed to
be compatible with the RX-11, or with the Terak 8510A
drives. Hard disks are assumed to be compatible with the
RK05.
The system is normally supplied with the assumption that
the user has a simple line-oriented ASCII terminal. The
SETUP program can be used to configure control codes for
more appropriate use of most CRT terminals. Copies of the
system supplied to users of the Terak 8510A make fairly
extensive use of the special graphics and character generator
facilities of that machine.
8080 and Z80 Versions
The Z80 version is now running on the Tektronix 8002
Microprocessor Development Aid system, for which Tektronix
has supplied substantial support to the project. The 8080
version uses virtually the same source code as is used on the
Z80, with conditional assembly altering certain passages in the
source to substitute for a few of the extended Z80 instructions
that proved useful.
Release of the 8080/Z80 version of the system of other
machines has been held up primarily because of the awkward¬
ness of handling I/O. We currently have a Zilog Development
System, a Processor Technology SOL system, and a Computer
Power and Light COMPAL-80 system. The floppy disk pro¬
visions for each of these machines is non-standard. As a result,
we have been forced to down-load programs via serial inter¬
faces to get from the LSI-11 host machines used for develop¬
ment over to the new 8080 or Z80 based host. This has proven
to be a very time consuming process, and a serious bottleneck
in our work. Moreover, we are somewhat amazed to find that
the assembly of large programs on these machines runs almost
a factor of ten slower than compilation of PASCAL programs
that carry out similar tasks! Clearly, something has to give if
we are to reach the objective of distributing PASCAL systems
for more than a few 8080 and Z80 based machines.
The solution to this problem that we now plan to use is
based on the extensive market penetration of an operating
system called CP/M, which is a product of Digital Research
Inc. We have talked with many OEM and hobbyist users of the
8080 and Z80 who wanted to know when we would have the
PASCAL system operating under CP/M. We then learned that
CP/M is distributed in a package which assumes that most
users will write their own I/O drivers. In effect, CP/M estab¬
lishes a quasi standard for the interface between an 8080/Z80
operating system and its I/O drivers. With thousands of copies
working in the field, CP/M seems to be far ahead of the field
in this area. Accordingly, we have decided to release the UCSD
PASCAL System for 8080 and Z80 users in a form that will
work with I/O drivers and bootstrap loaders developed for use
with CP/M. This does not mean that our package will run
under CP/M. However, if CP/M runs on your machine it should
be relatively easy to install the PASCAL system on that
machine. We have been in contact with Digital Research on
this concept, and they have offered to cooperate. If you do
not have CP/M for your machine, the implementation package
may be obtained from Digital Research Inc., Box 579, Pacific
Grove, CA 93950 for $70. Since CP/M has been implemented
on a very wide variety of 8080 and Z80 based machines, there
is a high probability that CP/M I/O drivers are already available
from Digital Research or someone else for your machine.
Alteration of our present interpreter to match the CP/M
I/O calling conventions has proven to be very simple, at least
on paper. We expect that some implementors of CP/M will
have installed standard console input routines which auto¬
matically echo to the standard console printer or display
device. This will necessitate a change, since our system uses
both echoing and non-echoing console input. At this writing,
the exact method to be used is under discussion. Barring some
unforseen calamity, copies of our system designed to run with
CP/M I/O drivers should be ready for distribution by early
January, 1978. The distribution medium will be IBM compa¬
tible floppy disks formatted in a manner yet to be finally
specified. We will undertake to transform the system for other
media and other formats, in general, only if a copy of the
necessary hardware is available in our laboratory, and only if
funds are available to pay for the extra conversion work.
For many of the 8080 based machines we have seen, the
most practical way to install our system will be to use 48K
bytes of RAM augmented with 8K bytes of ROM for the
interpreter. Any additional RAM or ROM required by the
host processor system will also be needed.
PASCAL Extensions and Alterations
We have attempted to implement faithfully as much as
possible of PASCAL as defined in Jensen & Wirth’s User
Manual and Report. The principal extensions to PASCAL
embodied in our system are related to STRING variables,
Turtle Graphics, handling of disk files, Segment (overlay)
Procedures, and several functions for support of the system
itself. Alterations include a prohibition against passing pro¬
cedure, the addition of EXIT (<procedurename>) to effect
a normal exit from the procedure named in the parameter, and
a change in READ applying to the interactive INPUT and
KEYBOARD files. Further details than given in this section
are given in our system release documents.
Type STRING is a pre-declared record containing a
character count followed by a packed array of characters.
Built-in procedures and functions include LENGTH,
POS(ition), INSERT, DELETE, COPY (i.e. extract),
CONCATenate, SCAN, FILLCHAR, MOVERIGHT, and
MOVELEFT. The last four of these also operate on conven¬
tional packed arrays of characters.
Turtle Graphics describes a technique originated by
Seymour Papert of MIT in which one can either MOVE a
cursor (called the “turtle”) an arbitrary number of screen
units in the current pointing direction, or TURN an arbitrary
number of degrees at the current position. A PENCOLOR
procedure allows the line drawn by a MOVE to be either
WHITE, BLACK, or NONE.
The disk file extensions allow working with fixed length
logical records corresponding to any legal <type>, which
might typically be a RECORD data structure. GET and PUT
operate normally through a window variable of the same
<type>. OPENNEW creates a new file, OPENOLD opens a
pre-existing file, and CLOSE allows saving or purging a file.
SEEK (which will be distributed with the 1.4 system for the
first time) allows random access to logical records within a file.
SEGMENT Procedures are separately compiled and then
linked into the host program using the LINKER. A Segment
procedure is only loaded into main memory when it is
entered for the first time, and its memory space is deallocated
Page 18
120
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
upon exit from the first invocation.
READ(INPUT , X) is defined by Wirth as X: =INPUTt;
GET(INPUT); which we find to be extremely awkward for
interactive use. Our solution is to place the implied GET
before the implied assignment in the case of interactive files
of type TEXT. READ operates as defined in Wirth’s Report
for other TEXT files.
PACKED records on our system which fit within 16 bit
fields are automatically packed and unpacked without
explicit action by the programmer.
Introductory PASCAL Course and Textbook
Many of those inquiring about our system have heard about
it through having seen the textbook “Microcomputer Problem
Solving Using PASCAL” by the author of this note, published
this fall by Springer Verlag. If you haven’t seen a copy, they
may be obtained from Springer at 175 Fifth Ave., New York
City, NY 10010.
The book is the basis for teaching the large attendance
introductory computer science course at UCSD. This course
comes close to matching the specifications for course CS1 in
the recently published curriculum recommendations from
ACM’s SIGCSE. The approach is non-numerical as far as
practical, as a tactic to reach the many students who come to
us with inadequate preparation in high school mathematics.
The problem solving and programming approach taught is
the same as we would teach even if all the problem sets were
mathematics oriented. Because many problem examples and
illustrations use our string and graphics extensions to PASCAL,
the textbook currently assumes that the student will have
access to a computer which mns under the UCSD PASCAL
system. We will be glad to discuss the possibility of conversion
to other software systems, but have very limited resources to
apply to such conversions. There are several stand-alone
microcomputers now being sold in large quantities on which
our system would run, given a small conversion effort, and we
would welcome support funds to pay for such conversions.
Software in the form of automated quizzes is available with
our system release for those who may wish to teach using the
textbook. Each chapter in the book has a list of study goals
for the students to achieve. Wherever appropriate, the quizzes
test for mastery of the topics enumerated in the goals lists.
The quiz programs have been implemented using a set of
CAI primitive routines patterned after the well known
DIALOG CAI system developed at U.C. Irvine by Alfred Bork
and his colleagues.
The introductory course is taught using Keller’s Personal¬
ized System of Instruction (PSI). PSI has been found to be a
more successful method of instruction than any other method
commonly used in universities and colleges. This success is
achieved, almost completely without conventional lectures, by
using experienced students as Learning Assistants called
“proctors”. The characteristics of this method make us believe
that it is possible to offer this course, or others constructed
along the same lines, on a packaged basis for use at other
institutions. A separate paper describing this possibility in
detail called “Microcomputer Based Mass Education” is
available from the writer of this status report.
Tele-Mail User Support Facility
We have reached the point where it will be possible for us
to begin operating a dial-in computer “mailbox” by early in
the winter quarter. We have been using the Terak 8510A
machines occasionally as intelligent terminals for exchanging
messages via the large B6700 computer operated by the
campus computer center. Our own Tele-Mail facility will use
its own single telephone number reachable directly from the
national dialed telephone network, or internally via the
California state government telephone network. Mail sub¬
scribers to our software release will be notified when this
mailbox facility is ready to be used.
The mailbox will be operated primarily to serve users of
our software system. It will provide notices of recent bug
corrections, down-loading of program files (either source or
object) where appropriate, notices on new additions to the
software and new machines on which implementations have
been completed, and other useful information from us to the
users. It will also serve as a means for us to collect messages
from specific users, and to answer them expeditiously, without
the hassle of both parties having to be at their telephones at
the same time.
Through the use of block transfer software, the mailbox
will make relatively efficient use of the dialed telephone net¬
work. We would like to begin immediately by offering a dial-
in port at 1200 bits per second. However, the present state of
confusion in the industry at that speed (which is the fastest
one can use with acoustic couplers) leads us to move
cautiously. We can and will install a port at 300 bits per
second using the standard Bell 103A equivalent conventions.
The system will answer an incoming call from an ordinary
terminal by providing a brief summary of recent developments.
It will otherwise expect a “handshake” from a special file
transfer program that we will provide to users of our software
package. This program will be the means of interchange based
on efficient transfer of messages in the form of complete files.
If you wish to send an ordinary text massage to us, you will
prepare the message using either of the editors built into the
system. Only after the massage is complete will you need to
make the telephone connection.
Forthcoming Improvements
As mentioned earlier, our next significant improvement in
the software will be a more flexible system allowing libraries
of programs. One of the main reasons for doing this will be to
allow the software to be configured to make efficient use of
main memory in cases where the user does not need all of the
built-in facilities. For example, we have no need for turtle
graphics when compiling large system programs.
One of the long awaited features of the new library system
will be an arrangement allowing mixture of PASCAL proce¬
dures with Assembly language routines and/or procedures
compiled directly to the native code of the host machine.
The necessary assemblers and code generation will come some¬
what after the library system is operational. If all goes well,
the library system should be ready to distribute during the
winter quarter of 1978. The assemblers and native code
versions of the compiler will come somewhat later as time for
the necessary work permits.
Many people have asked whether we have in mind exten¬
sions to support Concurrent PASCAL, or similar facilities to
allow independent processes running concurrently. This is
something we would like to do eventually, but our current
resources do not allow making definite plans in this area.
ADCIS MET IN DALLAS
News Release Received: 78 Jan 9
The 1978 Winter Meeting of the Association for the Devel¬
opment of Computer-based Instructional Systems (ADCIS)
was held in Dallas, Texas, March 1-4, 1978. For further
information, contact the conference host, Carol Luce, Educa¬
tional Service Center, Region 100,400, East Spring Valley Rd,
Richardson, TX 75080, (214) 231-6301.
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 19
121
ACT
An 8080 Macroprocessor
BY ALEX CECIL
Lawrence Livermore Laboratory
ACT is a macro text interpreter which runs under the CP/M
operating system on an Intel 8080 compatable microcomputer.
More than 16K bytes of RAM are needed. ACT uses the same
algorithm as TRAC [2] (“TRAC” is a registered trademark of
Rockford Research Institute) and a set of primitive functions
which are similar to those in the TRIX interpreter [ 1 ]. ACT
also uses the special characters @ (J } in place of TRAC’s
#(,). ACT has been used to control jobs on a large time shar¬
ing system and to format diskette files; it is generally too slow
for efficient human interaction.
Logically (but not necessarily psychologically), the syntax
is very simple. Program and data are character strings which
are handled by the same rules. There are three structures:
M
@ (op Iarg 1 I arg2 |... | argn j
(® @{op | arg 1 | arg2 |.. . | argn }
The first is a literal quote; the contents are passed on as the
value. The second performs the indicated operation on the
argument strings and immediately rescans the resulting value.
The last form performs the operation and passes the value to
the next higher level function. Any op or argument may have
any of the three forms. For more information on the scanning
algorithm see any of the published descriptions of TRAC.
There is a version of ACT which uses upper case letters for
the command names and the special characters A [.,] ' instead
of @{| } . Also, the meta-character is the exclaim (!).
Execute line
act
act < file-name >
act < file -name > < options >
If a file name is given, then the ACT macros in the file are
read first; < file-name > has the general form “d:x.y”. The
string @ in is initialized to the characters between “act” and
the return.
As a special case, <options> may be the three characters
nh, where A is the caret (or up arrow), and hh is a hex page
number. Free storage is allocated from the end of the inter¬
preter up to, but not including, page hh or FBASE if A hh is
not given.
Non-disk I/O and debug
@ {re|prompt] “read string”
Value is a line of input from the console (via CP/M call
#10), or the next string from the input file. Line-feed,
return, and tab characters from the input file are ignored; a
string is terminated by the meta-character (~) or by the
end-of-file. Comments on the input file are enclosed
within matching left quotes ( N ). Input files generally do
not end with the meta-character.
@(ps | a | a |.. .^ “print string”
Each argument (after the “ps”) is printed on a separate line;
but there is no CR-LF after the last argument.
<® (so | message] “send to Octopus”
The message is sent over the selected Octopus channel.
Usually the message does not end with an Octopus end-
message character. The echo is lost. (Note: “Octopus” is
the name of the LLL time sharing system. The so and ro
functions talk to Octopus over a serial interface as an ordin¬
ary terminal. Separate documentation illustrates how this
hardware dependent function can be patched for different
I/O ports.)
@ (ro | x | s 111 eom] “read Octopus”
If the Octopus time-out is greater than zero, then a mes¬
sage terminator is sent. This terminator either causes a
previous “so” message to be delivered or a log-out in case
there was no previous “so” and the terminator is a
control-D. Octopus output is then collected in the string
@ro until the string X is encountered or until the time-out
interval passes since the last character. The value is s if x
was found, otherwise f. If s and f are omitted, the value is
null. (Note this inconsistency with the functions gc and in.)
A null x will always fail to match.
A non-null last argument (eom) will change the Octopus
message terminator. The argument eom must be the two
hex characters which correspond to the terminator. The
terminator is initially a control-D.
@ fio | x | x |...] “input-output parameters”
Each argument x is a letter (o, t, m) followed by an
associated parameter:
oa selects Octopus channel a. (initial value)
ob selects Octopus channel b.
tn sets the Octopus time-out to n seconds. E. g. 1120.
me redefines the meta-character to be the character c.
p print: terminal output is thru CP/M, “fw” applies,
d display: direct output, “fw” does not apply.
Note: This option is hardware dependent.
@ {fw |n ] “form width”
The “print string” function will start a new line after n
characters. The initial form width is 80. However, this does
not apply if an @ {io | p ] is in effect.
@{tn] “trace on”
Turn the trace mode on and save the previous mode. Note:
An @ {io|dj is implicitly given so that the output will
wrap around; see the fw function above.
@ (tf ] “trace off’
Restore the previous trace mode, up to eight levels.
(® { nb J “number of blocks”
Value is the number of sixteen word free storage blocks.
@{fs|n|m] “free storage”
Free storage is augmented by the memory locations n up
to but not including m; n and m are decimal and must be
multiples of 16.
@[vn] “version number”
Value is the ACT version number.
Page 20
122
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
Disc I/O
The file name has the general form “d:x.y”. If d is omitted,
the system drive is selected; lower case characters in the
name are mapped to upper case. The number of the next
record to read or write is set to n. (Records are numbered
sequentially starting at zero; each record consists of 128
characters.) If the open fails the value is f; otherwise the
value is s.
Since only one file can be open at a time, the record
number of the current file may need to be saved by @ [rn}.
Also, a currently opened output file must be closed before
another open.
@{mf| file-name Is |f J “make file”
If the named file can be created, the value is s; otherwise
the value is f. The current record number is set to zero.
@ [cf | s | f ] “close file”
The currently opened file is closed. The value is f if there is
a close error, otherwise s.
@ [df [ “destroy file”
The current file is destroyed.
@ (rn [ “record number”
The value is the record number of the next record to read
or write. This number applies to the currently opened file.
@ { wf | string-name | x | s | f ^ “write file”
Characters from the named string, starting with the first,
are written to the currently opened file. If x is null, then
the last partial record is not written; instead, the form
pointer of the named string is left positioned at the remain¬
der. For example, the output for the next write could be
constructed by: . -i
@ { ns | name | @@ [in |name | <more output> j .
If x is non-null, then the first character of x is used to
pad out the remainder of the record and the record is writ¬
ten. An entire record of pad characters is written if the
previous output ended on a record boundary.
The value is f if there is a write error, otherwise s.
@ (rf | string-name | m | s | f J “read file”
The next m records are read from the currently opened
file and appended to the named string. The value is f if the
physical end of file is reached, otherwise s.
@frdj “read dialect”
The value is the text from the currently open file. The file
is read starting with the record set by the open file. The
input is processed in the same manner as described for the
rs function. Thus, one program can load another in the
same way as is done when a file name is put on the execute
line after “act”. Warning: No of or mf commands can be
executed until the file has been read.
Control and delay
<®[eq|a|b|s|b|s|...|b|s] or @ [eq|a|b|s|b|s|...
1 f [“equal”
The value is the first s for which the preceding b is equal
to a, where “equal” means string equality. If the last argu¬
ment is not one of a “b-s” pair, then it provides an “else”
value. .
@[ge|n|m|s|f] “greater than or equal to”
The value is s if n is numerically greater than or equal to m,
otherwise the value is f.
@ [nt | name | s | f} “null test”
The value is s if the named string is null, otherwise the value
isf.
@ (ex 1 x J “exit”
Clear the active and neutral strings; then set the active
string to x.
@ (st | “stop”
Return to CP/M.
@[zz|n[ “sleep”
Sleep for n/10 seconds.
String ops and hex-to-characters
@ {ns | name j value | name | value |. .. ] “name string”
Create one or more strings with the given values.
@ [as | name | x | name | x |...] “append string”
Append the string x to the named string.
@ [ss |name | arg | arg |...]• “segment strong”
Create arguments in the named string.
@ Id |name | arg | arg |... J or @ [name | arg| arg | . . .} “call”
Return the named string, starting at the first character, with
the actual arguments substituted for those corresponding
substrings which were matched by a previous “segment
string”.
@ [gc | name | n | s | f ) “get characters” (4 or more arguments)
Move the form pointer over n characters, or to the end of
the form if there are fewer than n characters remaining. The
characters passed over are put into the string “@gc”.
Return s if there are n characters after the form pointer in
the named string, otherwise return f.
@ j gc | name | n } “get characters” (3 arguments)
Like gc with 4 or more arguments except that the value of
@gc is also the value of this function.
@ [gc | name]
Return the total number of characters in the named form.
@ [in | name | p | s | f J “initial” (4 or more arguments)
Starting at the form pointer, search for the substring p.
The characters which are passed over in the search, up to
but not including p, are put into the string “@in”. If p is
found return s, otherwise return f. The form pointer is left
positioned after s, or at the end of the form. Null p always
fails.
@[ in | name | p j “initial” (3 arguments)
Like in with 4 or more arguments except that the value of
@in is also the value of this function.
@[ in | name [ “initial” (2 arguments)
Return the characters from the form pointer to the end of
the form; also set @in to this value. The form pointer is left
past the end of the form.
@ [cr | name j “call restore”
Move the form pointer of the named string to the beginning
of the string.
@ [dd | name | name |... J “delete definitions”
Delete the named strings.
@ fpk|hex ] “pack”
Return the characters whose hex values are given.
@[uk|xj “unpack
Return the hex
Arithmetic
form of the string x.
@[ad|n |n|..“add”
Return the sum of the arguments. Numbers are represented
by signed decimal integers whose magnitude is less than
32768
@{su|n|m[ “subtract”
Return n-m.
@ [ml | n | n |.. .] “multiply”
Return the product of the arguments.
@[dv|n|m] “divide”
Return n/m.
@\md|n|m[ “mod”
Return n mod m.
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 21
123
Special Strings
@ cb “console break”
The value of this string is the last console break character.
@ im “idle macro”
This macro is loaded whenever the active string is empty.
The initial value of @im is @ £ps| @ ^ rs | .11 , but @im may
be changed at any time.
Console “break”
The last character of any console input, other than for the
@ rs function, is saved in the string @cb. Moreover, if the
input character is an ESC, then you will be prompted to type
one of the letters t, n or i which will turn the trace on (t),
turn the trace off (n), or reload the idle macro (i). Console
input will stop output, or cause an immediate return from the
zz or ro functions.
Generating a COM File with a Preloaded ACT Program
A COM file containing the ACT interpreter and a preloaded
macro file may be created as follows, assuming a 32K system.
1. Append something like the following to your macro file
@fnsl@im|J
@ [fs 126368129184}
@fns|@im|(@[ps|@\rs|.
@s start"!
])
@ st
where “start” is the name of your top level macro. Note
that the fs function adds 6700 hex up to 7200 hex to the
free storage list after the program is started (step 4). Free
storage normally extends to FBASE which is 7200 hex in
a 32K system.
2. Load your program by typing
act macro-file *6 7
where ” is the caret, or up arrow. Free storage will
extend up to 6700 hex; if your program needs more space,
then you need more than 32K to make a COM file. TTie st
function at the end of your file will return control to CP/M.
3. Make a COM file with the SAVE command
save 103 code.com
4. Run the code by typing either of the following
code
code options
The options will be in the string @in.
Error Messages
DISK EOF: The rs function is trying to read beyond the end
of file.
FREE STORAGE IS EMPTY: The combined storage required
for named strings, string names, and active and neutral
strings has exceeded the allocated memory. At this point,
the active and neutral strings are cleared and control given
to the @im macro. The second time this happens, control
returns to CP/M.
NS STACK OVERFLOW: The number of unprocessed
arguments exceeds 250. The level of nesting or the number
of arguments is excessive. For example, the number of
arguments for a ns should not get much over 200.
References
1. Moll, H., "TRIX — An interactive, interpretive language for manipu¬
lating strings of characters." Lawrence Livermore Lab Report
UCID-30100.
2. Moors, C. N., "TRAC, a Procedure describing Language for the
Reactive Typewriter." Comm. ACM9, 3 (March, 1966)
3. Moors, C. N., "TRAC, A Text Handling Language." Proc. ACM
20th Nat. Conf., Cleveland, August, 1965.
4. Wegner, Peter, Programming Languages, Information Structures,
and Machine Organization. McGraw-Hill Book Co., 1968.
Note: Since the listing of ACT is quite long, we are publishing
the PL/M listing only in this issue. In the next issue we will
print the symbol table and assembler listing along with a table
referencing selected line numbers from the PL/M version
to the assembler listing - TR W.
4
8080 PLM1 VERS 3.0
00001 1 /* STANDARD LANGUAGE EXTENSIONS. 6/16/75 */
00002 1 DECLARE
00003 1 TRUE LITERALLY 'OFFH',
00004 1 FALSE LITERALLY 'O',
00005 1 FOREVER LITERALLY 'WHILE TRUE',
00006 1 FOR LITERALLY 'DO',
00007 1 ENDFOR LITERALLY 'END;',
00008 1 FI LITERALLY 'END:'
00009 1 SELECT LITERALLY 'DO CASE',
00010 1 OF LITERALLY ';',
00011 1 ENDSELECT LITERALLY 'END;',
00012 1 FUNCTION LITERALLY 'PROCEDURE',
00013 1 ENDFUNCTI ON LITERALLY 'END',
00014 1 ENDPROCEDURE LITERALLY 'END'.
00015 1 ENDDO LITERALLY 'END; 1 ,
00016 1 BEGIN LITERALLY 'DO;';
00017 1
00018 1 100H: START:
00019 1 /* ACT VERSION 31 10/17/77 */
00020 1 /* DON'T FORGET TO CHANGE PFSVN */
00021 1
00022 1 /* TO CHANGE TO UPPER CASE FOR TTY MOD33:
00023 1 1. CHANGE SPECIAL ACT CHARACTERS,
00024 1 2. CHANGE ALPHABET (LITSA ETC.),
00025 1 3. CHANGE PFSLIST.
00026 1 4. CHANGE METASCHAR TO APOSTROPHE.
00027 1 */
00028 1
00029 1
Page 22
124
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
i
00030 1
00031 1
00032 1
00033 1
00034 1
00035 1
00036 1
00037 1
00038 1
00039 1
00040 1
00041 1
00042 1
00043 1
00044 1
00045 1
00046 1
00047 1
00048 1
00049 1
00050 1
00051 1
00052 1
00053 1
00054 1
00055 1
00056 1
00057 1
00058 1
00059 1
00060 1
00061 1
00062 1
00063 1
00064 1
00065 1
00066 1
00067 1
00068 1
00069 1
00070 1
00071 1
00072 1
00073 1
00074 1
00075 1
00076 1
00077 1
00078 1
00079 1
00080 1
00081 1
00082 1
00083 1
00084 1
00085 1
00086 1
00087 1
00088 1
00089 1
00090 1
00091 1
00092 1
00093 1
00094 1
00095 1
00096 1
00097 1
00098 1
00099 1
00100 1
00101 1
00102 1
00103 1
00104 1
00105 1
00106 1
00107 1
00108 1
00109 1
00110 1
00111 1
00112 1
Number 23
/*** SPECIAL CHARACTERS ***/
DECLARE /* CONTROL CHARACTERS */
NUL LITERALLY '00H',
SOH LITERALLY '01H', /* CONTROL-A */
ETX LITERALLY '03H', /* CONTROL-C */
EOT LITERALLY '04H', /* CONTROL-D */
ENQ LITERALLY '05H', /* C0NTR0L-E #/
BEL LITERALLY '07H',
HT LITERALLY '09H',
LF LITERALLY 'OAH',
VT LITERALLY 'OBH',
CR LITERALLY 'ODH',
50 LITERALLY 'OEH', /* CONTROL N */
51 LITERALLY 'OFH', /* CONTROL 0 */
DC3 LITERALLY '13H',
NAK LITERALLY '15H', /* CONTROL-U */
SYN LITERALLY '16H',
ETB LITERALLY '17H', /* CONTROL-W */
CAN LITERALLY '18H', /* CONTROL-X */
EM LITERALLY '19H', /* CONTROL-Y */
SUB LITERALLY '1 AH', /* CONTROL-Z */
ESC LITERALLY '1BH',
DEL LITERALLY '7FH',
PHI LITERALLY '80H', /* MARKS AN UNUSED CHAR. POSITION */
NIL LITERALLY '81H'; /* MARKS THE END OF A STRING, SEE NILNIL IN FSSGET */
DECLARE /* SPECIAL ACT CHARACTERS */
FUNSCH LITERALLY '40H', /* 'AT' CHARACTER (OR UP-ARROW) */
LEFTSDELIM LITERALLY '7BH', /* LEFT BRACE (OR SQUARE BRACKET) */
ARGSDELIM LITERALLY '7CH', /* BAR (OR COMMA) */
RIGHTSDELIM LITERALLY '7DH', /* RIGHT BRACE (OR SQUARE BRACKET) */
COMMSDELIM LITERALLY '60H'; /* GRAVE ACCENT (OR APOSTROPHE) */
DECLARE /* ALPHABET (EITHER LOWER OR UPPER CASE) */
LITSA LITERALLY '61H',
L1T$B LITERALLY '62H',
LITSC LITERALLY '63H',
LITSD LITERALLY '64H',
LITSE LITERALLY '65H',
LIT*F LITERALLY '66H',
LITSG LITERALLY '67H',
LITSH LITERALLY '68H',
LIT#I LITERALLY '69H',
LIT#J LITERALLY '6AH',
LITSK LITERALLY '6BH',
LITSL LITERALLY '6CH',
LIT$M LITERALLY '6DH',
LIT*N LITERALLY '6EH',
LIT#0 LITERALLY '6FH',
LITSP LITERALLY '70H' ,
LITSQ LITERALLY '71H',
LIT$R LITERALLY '72H',
LITSS LITERALLY '73H',
LIT#T LITERALLY '74H',
LITSU LITERALLY '75H',
LIT$V LITERALLY '76H',
LIT$W LITERALLY '77H'.
LIT$X LITERALLY '78H',
LITSY LITERALLY '79H',
LITSZ LITERALLY '7AH';
/*** DATA WHICH MUST BE LOCATED MOD 16 ***/
DECLARE /* THIS MUST BE THE FIRST NON-LITERAL DECLARE */
ATSGC DATA (0,0,FUNSCH,LIT$G,LITSC,NIL,0,0,0,0), /* 106-10F */
AT#IN DATA (0,0,FUNSCH,LITSI,LITSN,NIL). /* 110-115 */
AT$R0 DATA (0,0,FUNSCH,LITSR,LITSO,NIL,0,0,0,0), /* 116-11F */
ATSCB DATA (0,0,FUNSCH,LITSC,LITSB,NIL); /* 120-125 */
/#** BASIC I/O, SYSTEM CALLS ***/
DECLARE /* I/O READY TESTS FOR CONSOLE */
/* 'IN' REFERS TO TERM INAL-TO-OCTOPUS DIRECTION */
/* 'OUT' REFERS TO OCTOPUS-TO-TERMINAL DIRECTION */
CPMSPRINTSFLAG BYTE INITIAL (TRUE),
TERMSSTATUS LITERALLY '1', /* HARDWARE */
TERMSDATA LITERALLY 'O' /* HARDWARE */
TERMSINSREADY LITERALLY 'M0N2(11,0)',
TERMSOUTSREADY LITERALLY 'ROR(M0N2(11,0),2)'j
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 23
125
00113 1 DECLARE
00114 1 (CONSWIDTH, CONSCOLUMN) BYTE INITIAL <80.0),
00115 1 CONSIN BYTE INITIAL (TRUE), /* CONSOLE INPUT (DISK INPUT IF FALSE) */
00116 1 CONBUF(82) BYTE INITIAL (80,0,1).
00117 1 OCTOSTIMEOUT ADDRESS INITIAL (120),
00118 1 TFCBSPTR ADDRESS INITIAL (5CH), /* TRANSIENT FILE CONTROL BLOCK */
00119 1 TFCB BASED TFCBSPTR BYTE,
00120 1 TBUFFSPTR ADDRESS INITIAL (80H), /* TRANSIENT FILE BUFFER */
00121 1 TBUFF BASED TBUFFSPTR BYTE,
00122 1 TBUFFSINDEX BYTE INITIAL (128),
00123 1 ENDSOFSFILE LITERALLY 'SUB',
00124 1 0CTOSE0M BYTE INITIAL (EOT),
00125 1 METASCHAR BYTE INITIAL (7EH), /* TILDA OR EXCLAIM */
00126 1 PRELOADED BYTE INITIAL (FALSE),
00127 1 (DEFAULTSDRIVE,PREVIOUSSDRIVE,CURRENTSDR IVE) BYTE;
00128 1
00129 1 DECLARE /* SOME GENERAL PURPOSE TEMPS */
00130 1 TEMPSPTR ADDRESS,
00131 1 DUMMY BYTE,
00132 1 I TEMP BYTE;
00133 1
00134 1
00135 1 /*** BASIC I/O ***/
00136 1
00137 1 DECLARE
00138 1 BDOS LITERALLY '5H' ,
00139 1 FBASEA ADDRESS INITIAL (6H),
00140 1 FBASE BASED FBASEA ADDRESS,
00141 1 EXIT LITERALLY 'CALL M0N1(0,0)';
00142 1
00143 1 M0N1: PROCEDURE(F,A);
00144 2 DECLARE F BYTE, A ADDRESS;
00145 2 GO TO BDOS:
00146 2 ENDPROCEDURE M0N1;
00147 1
00148 1 M0N2: FUNCTI ON(F,A) BYTE:
00149 2 DECLARE F BYTE, A ADDRESS;
00150 2 GO TO BDOS;
00151 2 ENDFUNCTION M0N2;
00152 1
00153 1 CRLF: PROCEDURE;
00154 2 CALL M0N1(2,CR);
00155 2 CALL M0N1(2,LF);
00156 2 C0N$C0LUMN=0;
00157 2 ENDPROCEDURE CRLF;
00158 1
00159 1 PRINTSCH: PROCEDURE(CH);
00160 2 DECLARE CH BYTE;
00161 2 CALL M0N1(2,CH);
00162 2 IF CH = CR THEN DO; C0N$C0LUMN=0; FI
00163 2 /* NOTE... SHOULD HANDLE NON-GRAPHIC CHARACTERS */
00164 2 IF (CONSCOLUMN:=CONSCOLUMN+1) = CONSWIDTH THEN DO;
00165 2 CALL CRLF;
00166 3 FI
00167 2 ENDPROCEDURE PRINTSCH;
00168 1
00169 1 DISPLAYSCH: PROCEDURE(CH);
00170 2 /* SEND A CHAR TO TERMINAL. NOTE: HARDWARE DEPENDENT */
00171 2 DECLARE CH BYTE;
00172 2 DO WHILE ROR(INPUT(TERMSSTATUS),2); ENDDO
00173 2 OUTPUTCTERMSDATA)=NOT CH;
00174 2 END DISPLAYSCH;
00175 1
00176 1 READSCH: FUNCTION BYTE;
00177 2 RETURN M0N2(1,0):
00178 2 ENDFUNCTI ON READSCH;
00179 1
00180 1 CONSBREAK: FUNCTION BYTE;
00181 2 RETURN M0N2(11,0);
00182 2 ENDFUNCTION CONSBREAK;
00183 1
00184 1 PRINTSMESS: PROCEDURE(MESSSPTR);
00185 2 DECLARE MESSSPTR ADDRESS;
00186 2 CALL M0N1(9,MESSSPTR);
00187 2 CALL CRLF:
00188 2 ENDPROCEDURE PRINTSMESS;
00189 1
00190 1 SELECTSDRIVE: PROCEDURE;
00191 2 IF TFCB(0) = 0 THEN DO;
00192 2 CURRENTSDR IVE=DEFAULTSDR IVE;
00193 3 END: ELSE DO;
00194 2 CURRENTSDRIVE=(TFCB(0) AND 7)-1;
00195 3 TFCB(0)=0;
00196 3 FI
00197 2 IF PREVIOUSSDRIVE <> CURRENTSDRIVE THEN DO;
00198 2 PREVIOUSSDRIVE = CURRENTSDR IVE;
00199 3 CALL M0N1(14,CURRENTSDRIVE);
00200 3 FI
00201 2 ENDPROCEDURE SELECTSDRIVE;
00202 1
Page 24
126
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
00203 1
00204 2
00205 2
00206 2
00207 2
00208 2
00209 1
00210 1
00211 2
00212 2
00213 2
00214 2
00215 2
00216 1
00217 1
00218 2
00219 2
00220 2
00221 2
00222 3
00223 3
00224 3
00225 3
00226 2
00227 1
00228 1
00229 1
00230 1
00231 1
00232 1
00233 1
00234 1
00235 1
00236 1
00237 1
00238 1
00239 1
00240 1
00241 1
00242 1
00243 2
00244 2
00245 2
00246 2
00247 1
00248 1
00249 2
00250 2
00251 2
00252 2
00253 2
00254 2
00255 3
00256 2
00257 3
00258 2
00259 1
00260 1
00261 2
00262 2
00263 2
00264 2
00265 3
00266 4
00267 4
00268 3
00269 2
00270 2
00271 1
00272 1
00273 1
00274 1
00275 1
00276 1
00277 1
00278 1
00279 1
00280 1
00281 1
00282 1
00283 1
00284 1
Number 23
UPPERSCASE: FUNCTION(CH) BYTE:
/* MAP A CHARACTER TO UPPER CASE */
DECLARE CH BYTE;
IF CH < 61H OR CH > 7AH THEN DO; RETURN CH; FI
RETURN CH-20H;
ENDFUNCTION UPPERSCASE;
WAITSMS: PROCEDURE(N);
/* N MILLI-SECOND DELAY (APPROXIMATE) */
DECLARE (I,N) ADDRESS;
I =0;
DO WHILE I < N: CALL TIME<7); 1=1+1; ENDDO
ENDPROCEDURE WAITSMS;
WAITSTENTH: PROCEDURE(N)J
/* N SECOND DELAY */
DECLARE (I,N) ADDRESS;
FOR 1=1 TO N:
IF CONSBREAK THEN DO; RETURN; FI
CALL TIME(255);
CALL TIME(255);
CALL TI ME(135);
ENDDO
ENDPROCEDURE WAITSTENTH;
/*** OCTOPUS I/O PRIMITIVES ***/
DECLARE
/* 'IN' REFERS TO TERM INAL-TO-OCTOPUS DIRECTION */
/* 'OUT' REFERS TO OCTOPUS-TO-TERMINAL DIRECTION */
OCTOSCHANNELSA BYTE INITIAL (TRUE),
OCTOSASSTATUS LITERALLY '5',
OCTOSASDATA LITERALLY '4' ,
OCTOSBSSTATUS LITERALLY '7' ,
OCTOSBSDATA LITERALLY '6',
OCTOSOUTSREADY LITERALLY 'OCTOSSTATUS'
OCTOSINSREADY LITERALLY 'ROR(OCTOSSTATUS,2)';
OCTOSSTATUS: FUNCTION BYTE;
/* RETURN THE TRUE (NOT COMPLEMENTED) OCTOPUS STATUS FOR THE SELECTED PORT */
IF OCTOSCHANNELSA THEN RETURN NOT INPUT(OCTOSASSTATUS);
RETURN NOT INPUT(OCTOSBSSTATUS);
ENDFUNCTION OCTOSSTATUS;
SENDSCH: PROCEDURE(CH);
/* SEND A CHARACTER TO THE SELECTED OCTOPUS PORT */
DECLARE CH BYTE;
DO WHILE NOT OCTOSINSREADY; ENDDO
IF OCTOSCHANNELSA THEN DO;
OUTPUT!OCTOSASDATA)»NOT CH;
END: ELSE DO;
OUTPUT(OCTOSBSDATA)=NOT CH;
FI
ENDPROCEDURE SENDSCH;
RECEIVESCH: FUNCTION BYTE;
/* GET A CHARACTER FORM THE SELECTED OCTOPUS CHANNEL */
DECLARE I ADDRESS;
FOR 1=0 TO 65000;
IF OCTOSOUTSREADY THEN DO;
IF OCTOSCHANNELSA THEN RETURN (NOT INPUT(OCTOSASDATA)) AND 7FH;
RETURN (NOT INPUT(OCTOSBSDATA)) AND 7FH;
FI
ENDFOR
RETURN OFFH;
ENDFUNCTION RECEIVESCH;
/*** BLOCK AND FREE STORAGE GLOBALS ***/
DECLARE
FSSFIRSTSPTR ADDRESS, /* FREE STORAGE HEAD */
BLOCKSLENGTH LITERALLY '16'
BLOCKSLAST LITERALLY '15'
PTRSMASK LITERALLY 'O^FFOH',
NOTSPTRSMASK LITERALLY 'OFH',
(FIRSTSGETASFLAG,FIRSTSGETBSFLAG,FIRSTSPUTASFLAG) BYTE,
(GETSCHASCHSPTR,PUTSCHASCHSPTR,PUTSCHASCURRENTSBLOCKSPTR) ADDRESS;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 25
127
/*** 0LOBALS FOR SCAN ALGORITHM ***/
00285 1
00286 1
00287 1
00288 1
00289 1
00290 1
00291 1
00292 1
00293 1
00294 1
00295 1
00296 1
00297 1
00298 1
00299 1
00300 1
00301 1
00302 1
00303 1
00304 1
00305 1
00306 1
00307 1
00308 1
00309 1
00310 1
00311 1
00312 1
00313 1
00314 1
00315 1
00316 1
00317 1
00318 1
00319 1
00320 1
00321 1
00322 1
00323 1
00324 1
00325 1
00326 1
00327 1
00328 1
00329 1
00330 1
00331 1
00332 2
00333 2
00334 2
00335 2
00336 2
00337 2
00338 2
00339 2
00340 1
00341 1
00342 2
00343 2
00344 2
00345 2
00346 2
00347 2
00348 2
00349 2
00350 2
00351 2
00352 2
00353 2
00354 2
00355 3
00356 3
00357 4
00358 4
00359 3
00360 4
00361 3
00362 2
00363 3
00364 3
00365 3
00366 3
00367 3
00368 3
00369 3
00370 3
00371 3
00372 3
00373 3
00374 2
00375 1
Page 26
128
DECLARE
NSSSTACK(255) ADDRESS INITIAL (11B.1B), /* NEUTRAL STACK, 8-BIT INDEX */
NS$STACK$INDEX BYTE, /* INDEX OF CURRENTLY 'OPEN' ARGUMENT */
NS9SAVESINDEX BYTE, /* INDEX OF FIRST ARGUMENT OF CURRENT FUNCTION #/
NSSCHSPTR ADDRESS, /* NEXT NEUTRAL CHARACTER ADDRESS */
NSSCH BASED NSSCHSPTR BYTE,
NSSARGSBREAK BYTE,
NSSARGSFLAG LITERALLY
NSSBEGINSENDSBIT LITERALLY
NSSFUNSBIT LITERALLY
NSSACTIVESBIT LITERALLY
NSSNULLSBEGINSEND LITERALLY
NSSFUNSMARKER LITERALLY
/* LAST FOUR BITS OF NS STACK ENTRY */
/* MARKS LIMITS OF NEUTRAL STACK */
/* MARKS FIRST ARG OF FUNCTION */
/* MARKS ACTIVE FUNCTION */
NSSLIMITSMARKER
'OOOOB',
'0001B',
'001 OB',
'01OOB',
'1001B'.
'ROR(LOW(NSSSTACKt NSSSTACK*INDEX)),1)
/* NS BEG IN-FUNCTI ON TEST »/
LITERALLY 'LOW ( NSSSTACK(NSSSTACKSINDEX))',
/* NS BEGIN-END TEST */
NSSACTIVESFLAG BYTE,
ASSBLOCKSPTR ADDRESS INITIAL(O), /* CURRENT BLOCK IN ACTIVE STRING */
ASSBLOCK BASED ASSBLOCKSPTR ADDRESS,
ASSCHSPTR ADDRESS, /* ADDRESS OF NEXT ACTIVE STRING CHARACTER */
ASSCH BASED ASSCHSPTR BYTE,
(SSSCHASPTR,SSSCHBSPTR,SSSCHCSPTR) ADDRESS, /* SUBSTRING SEARCH PTRS */
SSSMASK LITERALLY '11000000B',
SSSCHA BASED SSSCHASPTR BYTE,
MOVESPTR LITERALLY 'TRUE', /* FLAGS FOR ASSNEXTSCH CALL */
DONTSMOVESPTR LITERALLY 'FALSE'
TRACESFLAG BYTE, /* 8 BIT 'STACK'. LOW ORDER BIT IS CURRENT */
(NAMESPTR,ARGSPTR) ADDRESS, /* GENERAL USE IN PF'S AND TRACE */
NEXTSARG LITERALLY 'WHILE NOT LOW(ARGSPTR:=NEXT$NS)', /* IN PF'S */
VALUESPTR ADDRESS, /* USED BY PF'S TO RETURN THEIR VALUE */
VALUESCH BASED VALUESPTR BYTE,
(SSPTR,FSPTR) ADDRESS, /* USED BY PF'S FOR SUCCESS AND FAIL VALUES */
NULLSSTRINGSPTR ADDRESS, /* ORED WITH NSSBEGINSENDSBIT IN NS STACK */
DEADSSTART BYTE INITIAL (TRUE),
NOSEXSVALUE BYTE INITIAL (TRUE);
/*** FREE STORAGE AND OTHER BLOCK STRUCTURE UTILITIES ***/
FSSFREE: PROCEDURE(FREESTHISSPTR);
/* ADD THE INDICATED BLOCK TO THE FREE STORAGE LIST */
DECLARE
FREESTHISSPTR ADDRESS,
FREESTHIS BASED FREESTHISSPTR ADDRESS;
FREESTHIS=FSSFIRSTSPTR;
FSSFIRST$PTR=FREESTHISSPTR;
ENDPROCEDURE FSSFREE;
FSSGET: FUNCTION ADDRESS:
/* ALLOCATE A BLOCK FROM FREE STORAGE, RETURN ITS ADDRESS */
/* SET 'NEXT' FIELD TO END-CHAIN (ZERO HIGH BYTE) */
/* AND FILL WITH NILS */
DECLARE
FSSFIRST BASED FSSFIRSTSPTR ADDRESS,
GOTSPTR ADDRESS.
GOT BASED GOTSPTR ADDRESS,
GOTC BASED GOTSPTR BYTE,
FIRSTSEMPTY BYTE INITIAL (TRUE),
NILNIL LITERALLY '8181H';
IF HIGH(FSSFIRSTSPTR) = 0 THEN DO;
CALL PRINT$MESS(.'FREE STORAGE IS EMPTY S');
IF FIRSTSEMPTY THEN DO;
FIRST$EMPTY=FALSE;
GO TO START;
END; ELSE DO;
EX I T;
FI
END; ELSE DO;
G0T$PTR=FSSFIRSTSPTR;
FSSFIRST$PTR=FS$FIRST;
GOT = 0;
GOT(1)=NILNIL;
GOT(2)=NILNIL;
GOT(3)=NILNIL;
GOT(4)=NILNIL;
GOT(5)=NILNIL;
GOT(6)= NILNIL;
GOT(7)= NILNIL;
RETURN GOTSPTR;
FI
ENDFUNCTI ON FSSGET;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
00376 1
00377 2
00378 2
00379 2
00380 2
00381 2
00362 2
00383 3
00384 2
00385 1
00386 1
00387 2
00388 2
00369 2
00390 2
00391 2
00392 2
00393 3
00394 3
00395 3
00396 3
00397 2
00398 1
00399 1
00400 2
00401 2
00402 2
00403 2
00404 2
00405 2
00406 2
00407 2
00408 2
00409 2
00410 2
00411 3
00412 2
00413 2
00414 2
00415 2
00416 3
00417 2
00418 2
00419 2
00420 2
00421 3
00422 3
00423 2
00424 2
00425 1
00426 1
00427 2
00428 2
00429 2
00430 2
00431 2
00432 2
00433 2
00434 2
00435 2
00436 2
00437 2
00438 3
00439 3
00440 3
00441 2
00442 2
00443 3
00444 3
00445 3
00446 2
00447 2
00448 1
00449 1
00450 2
00451 2
00452 2
00453 2
00454 2
00455 2
00456 2
00457 2
00458 2
00459 2
00460 3
00461 3
00462 3
00463 2
00464 2
00465 3
00466 3
00467 2
00468 2
00469 1
FSSINIT: PROCEDURE(MINSADDRESS,MAXSADDRESS);
/* CREATE FREE STORAGE LIST */
/# MAXSADDRESS MUST BE A MULTIPLE OF BLOCKSLENGTH */
DECLARE (MINSADDRESS, MAXSADDRESS,BLKSPTR) ADDRESS;
FOR BLK$PTR=MINSADDRESS TO MAX$ADDRESS-BLOCKSLENGTH BY BLOCKSIFNOTH;
CALL FSSFREE(BLKSPTR);
ENDFOR
ENDPROCEDURE FSSINIT;
FREESCHAIN: PROCEDURE(BLOCKSPTR) ;
/# FREE ALL BLOCKS IN A CHAIN STARTING WITH BLOCKSPTR */
DECLARE (BLOCKSPTR,BLOCK BASED BLOCKSPTR,NEXTSPTR) ADDRESS;
IF (BLOCKSPTR:=BLOCK$PTR AND PTRSMASK) = NULLSSTRINGSPTR THEN DO; RETURN; FI
DO FOREVER;
IF HIGH(BLOCKSPTR) 3 0 THEN DO; RETURN; FI
NEXTSPTR 3 BLOCK;
CALL FSSFREE(BLOCKSPTR);
BLOCKSPTR=NEXTSPTR;
ENDDO;
ENDPROCEDURE FREESCHAIN;
APPENDSCH: FUNCTI ON(CH,BLOCKSPTR) ADDRESS;
/* STARTING WITH BLOCKSPTR (<>0), SEARCH FOR THE LAST BLOCK */
/* APPEND CH AND RETURN THE NEXT CHARACTER ADDRESS */
DECLARE
CH BYTE,
(BLOCKSPTR,BLOCK BASED BLOCKSPTR,CHSPTR) ADDRESS,
BLOCKC BASED CHSPTR BYTE;
IF HIGH(BLOCKSPTR) = 0 THEN DO; RETURN 0; FI
DO WHILE HIGH(BLOCK) > 0;
BLOCKSPTR=BLOCK;
ENDDO
CHSPTR 3 BLOCKSPTR+2;
DO WHILE BLOCKC <> NIL;
CHSPTR 3 CHSPTR +1;
ENDDO
BLOCKC=CH'
IF (LOW(CHSPTR:=CHSPTR+1) AND NOTSPTRSMASK) = 0 THEN DO;
BLOCK,CHSPTR 3 FSSGET;
CHSPTR=CHSPTR+2;
FI
RETURN CHSPTR;
ENDFUNCTI ON APPENDSCH;
GETSCHA: FUNCTI ON(INITIALSBLOCKSPTR) BYTE;
/.* RETURNS THE NEXT 8-BIT CHARACTER FROM CHAIN 'A' */
/* TO INITIALIZE FOR A NEW CHAIN. SET FIRSTSGETASFLAG TO TRUE */
/* CALLER MUST TEST FOR STRING TERMINAL */
/* GETSCHASPTR POINTS TO THE LAST RETURNED CHARACTER */
DECLARE
(INITIALSBLOCKSPTR.CURRENTSBLOCKSPTR) ADDRESS,
CURRENTSBLOCK BASED CURRENTSBLOCKSPTR ADDRESS,
(CH BASED GETSCHASCHSPTR,NEWSCHAIN) BYTE;
IF FIRSTSGETASFLAG THEN DO;
FIRSTSGETASFLAG 3 FALSE;
CURRENTSBLOCKSPTR=INITIALSBLOCKSPTR;
GETSCHASCHSPTR 3 CURRENTSBLOCKSPTR+1;
FI
IF (LOW(GETSCHASCHSPTR:=GETSCHASCHSPTR+1) AND NOTSPTRSMASK) = 0 THEN DO;
CURRENT$BLOCK$PTR=GETSCHA$CH$PTR-BLOCKSLENGTH;
CURRENTSBLOCKSPTR=CURRENT$BLOCK;
GETSCHA$CHSPTR=CURRENTSBL0CKSPTR+2;
FI
RETURN CH;
ENDFUNCTI ON GETSCHA;
GETSCHB: FUNCTI ON(INITIALSBLOCKSPTR) BYTE:
/* RETURNS THE NEXT 8-BIT CHARACTER FROM CHAIN 'B' */
/* TO INITIALIZE FOR A NEW CHAIN, SET FIRSTSGETBSFLAG TO TRUE */
/* CALLER MUST TEST FOR STRING TERMINAL */
DECLARE
(I NIT IALSBLOCKSPTR,CURRENTSBLOCKSPTR,CHSPTR) ADDRESS,
CURRENTSBLOCK BASED CURRENTSBLOCKSPTR ADDRESS,
(CH BASED CHSPTR,NEWSCHAIN) BYTE;
IF FIRSTSGETBSFLAG THEN DO;
FIRSTSGETBSFLAG=FALSE;
CURRENTSBLOCKSPTR 3 INITIALSBLOCKSPTR;
CH$PTR=CURRENT$BLOCKSPTR+1;
FI
IF (LOW(CHSPTR:=CHSPTR+1) AND NOTSPTRSMASK) = 0 THEN DO;
CURRENTSBLOCKSPTR=CURRENTSBLOCK;
CHSPTR 3 CURRENTSBLOCKSPTR+2;
FI
RETURN CH;
ENDFUNCT1 ON GETSCHB;
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 27
129
00470
00471
00472
00473
00474
00475
00476
00477
00478
00479
00480
00481
00482
00483
00484
00485
00486
00487
00488
00489
00490
00491
00492
00493
00494
00495
00496
00497
00498
00499
00500
00501
00502
00503
00504
00505
00506
00507
00508
00509
0051 0
0051 1
0051 2
0051 3
0051 4
0051 5
0051 6
0051 7
0051 8
0051 9
00520
00521
00522
00523
00524
00525
00526
00527
00528
00529
00530
00531
00532
00533
00534
00535
00536
00537
00538
00539
00540
00541
00542
00543
00544
00545
00546
00547
00548
00549
00550
00551
00552
00553
00554
00555
00556
00557
00558
00559
00560
00561
00562
00563
00564
00565
Page 28
130
1
2
2
2
2
2
2
2
2
2
2
2
2
3
3
3
2
2
2
3
3
2
1
1
2
2
2
2
2
2
2
2
2
2
2
3
4
3
2
1
1
2
2
2
2
2
2
3
3
3
3
2
2
3
3
3
3
2
2
2
2
3
2
2
1
1
2
2
2
2
2
2
2
2
2
3
2
2
1
1
2
2
2
2
2
2
2
2
3
4
5
4
5
4
3
2
PUTSCHA: PROCEDURE(INITIALSBLOCKSPTR,CHA);
/* PUT CHA INTO THE CHAIN 'A' */
/* TO INITIALIZE FOR A NEW CHAIN, SET FIRSTSPUTASFLAG TO TRUE */
/* AND SET INITlALSBLOCKSPTR TO FSSGET */
/* PUTSCHASCHSPTR POINTES TO THE NEXT CHAR TO BE STORED */
DECLARE
INITIALSBLOCKSPTR ADDRESS,
CURRENTSBLOCK BASED PUTSCHASCURRENTSBLOCKSPTR ADDRESS,
(CH BASED PUTSCHASCHSPTR,NEWSCHAIN,CHA) BYTE;
IF FIRSTSPUTASFLAG THEN DO;
FIRSTSPUTASFLAG=FALSE:
PUTSCHASCURRENTSBLOCKSPTR*INITIALSBLOCKSPTR;
PUTSCHASCHSPTR=PUTSCHASCURRENTSBL0CKSPTR+2;
FI
CH = CHA *
IF~(L0W(PUTSCHASCHSPTR:=PUT*CHASCHSPTR+1) AND NOTSPTRSMASK) * 0 THEN DO;
CURRENTSBLOCK.PUTSCHASCURRENTSBLOCKSPTR=FSSQET;
PUTSCHASCHSPTR*PUTSCHASCURRENTSBLOCKSPTR+2;
FI
ENDPROCEDURE PUTSCHA;
COPYSVALUE: PROCEDURE(SOURCESPTR.SINKSPTR);
/* SOURCESPTR IS THE ADDRESS OF THE SOURCE CHAIN */
/* SINKSPTR IS THE ADDRESS OF AN EMPTY BLOCK */
/* ONLY 7-BIT CHARACTERS ARE COPIED */
/* NOTE: PFSIN USES THE FINAL VALUE OF GETSCHASCHSPTR */
DECLARE
(SOURCESPTR,SINKSPTR) ADDRESS,
CH BYTE;
FIRSTSGETASFLAG.FIRSTSPUTASFLAG=TRUE;
DO WHILE (CH:=GET$CHA(SOURCESPTR)) <> NIL;
IF NOT ROL(CH,1) THEN DO;
CALL PUTSCHAtSINKSPTR,CH);
FI
ENDDO
ENDPROCEDURE COPYSVALUE;
STRINGSEQUALITY: FUNCTION(PTA,PTB) BYTE:
/* TRUE IF STRINGS CONTAIN THE SAME SEQUENCE OF 7-BIT CHARACTERS */
DECLARE
(PTA,PTB) ADDRESS,
(CHA,CHB) BYTE;
NEXTA: FUNCTION BYTE;
DO WHILE ((CHA:=GETSCHA(PTA)) <> NIL) AND R0L(CHA,1);
ENDDO
RETURN CHA;
ENDFUNCTI ON NEXTA;
NEXTB: FUNCTION BYTE;
DO WHILE ((CHB:=GETSCHB(PTB)) <> NIL) AND R0L(CHB,1);
ENDDO
RETURN CHB;
ENDFUNCTION NEXTB;
FIRSTSGETASFLAG,FIRSTSGETBSFLAG=TRUE;
DO WHILE NEXTA = NEXTB:
IF CHA = NIL THEN DO; RETURN TRUE; FI
ENDDO
RETURN FALSE;
ENDFUNCTI ON STRINGSEQUALITY;
NULLSTEST: FUNCTI ON(BLOCKSPTR) BYTE;
/* 'TRUE' IF THERE ARE NO 7-BIT CHARACTERS BEFORE THE NIL */
DECLARE
BLOCKSPTR ADDRESS,
CH BYTE;
IF HIGH(BLOCKSPTR) = 0 THEN DO; RETURN TRUE; FI
FIRSTSGETASFLAG=TRUE;
DO WHILE (CH:=GETSCHA(BLOCKSPTR AND PTRSMASK)) <> NIL;
IF NOT ROL(CH,1) THEN DO; RETURN FALSE; FI
ENDDO
RETURN TRUE;
ENDFUNCTI ON NULLSTEST;
PR 1NTSSTRING: PROCEDURE(BLOCKSPTR);
/# PRINT ALL 7-BIT CHARACTERS IN THE STRING */
DECLARE
BLOCKSPTR ADDRESS,
CH BYTE;
FIRSTSGETASFLAG = TRUE:
DO WHILE (CH:=GET$CHA(BLOCKSPTR AND PTRSMASK)X>NIL AND NOT TERMS INSRFADY;
IF NOT ROL(CH,1) THEN DO;
IF CPMSPRINTSFLAG THEN DO;
CALL PR INTSCH(CH);
END; ELSE DO;
CALL DI SPLAYSCH(CH);
FI
FI
ENDDO
ENDPROCEDURE PR INTSSTRING;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
00566 1
00567 1
00568 1
00569 1
00570 1
00571 2
00572 2
00573 2
00574 1
00575 1
00576 2
00577 2
00578 2
00579 2
00500 2
00581 2
00582 2
00583 3
00584 2
00585 1
00586 1
00587 2
00588 2
00589 2
00590 2
00591 2
00592 2
00593 2
00594 2
00595 2
00596 2
00597 3
00598 3
00599 3
00600 3
00601 4
00602 4
00603 5
00604 5
00605 4
00606 3
00607 3
00608 4
00609 4
00610 4
00611 3
00612 3
00613 2
00614 2
00615 2
00616 3
00617 2
00618 3
00619 3
00620 3
00621 2
00622 2
00623 2
00624 2
00625 2
00626 2
00627 3
00628 4
00629 5
00630 5
00631 5
00632 4
00633 3
00634 2
00635 2
00636 1
00637 1
00638 1
00639 1
00640 1
00641 1
00642 1
00643 1
00644 1
00645 1
00646 1
00647 1
00648 1
00649 1
00650 1
00651 1
00652 1
00653 1
00654 1
00655 1
00656 1
00657 1
00658 1
/*** OCTOPUS I/O UTILITIES ***/
CLEAR$OCTO$0UTPUT: PROCEDURE;
CALL WAITSTENTH C 2);
DO WHILE 0CTOSOUTSREADY; DUMMY=RECEIVESCH; CALL WAIT$TENTH(2); ENDDO
ENDPROCEDURE CLEARSOCTOSOUTPUT;
SENDSSTRING: PROCEDURE(BLOCKSPTR);
/« SEND A MESSAGE TO OCTOPUS. (USUALLY WITHOUT END-OF-LINE CHARACTER) */
/* IGNORE THE ECHO */
DECLARE BLOCKSPTR ADDRESS, CH BYTE;
CALL CLEARSOCTOSOUTPUT;
FIRST$GETA$FLAG=TRUE;
DO WHILE (CH:--GETSCHA(BLOCKSPTR)) <> NIL;
IF NOT ROL(CH,1) THEN DO; CALL SENDSCH(CH); FI
ENDDO
ENDPROCEDURE SENDSSTRING;
RECEIVESSTRING: FUNCTION(ENDSMESSAGESPTR) BYTE;
/* RECEIVE AN OCTOPUS MESSAGE. VALUESPTR WILL ADDRESS IT */
/* VALUE IS FALSE IF TIME-OUT BEFORE END-MESSAGE IS RECOGNIZED */
/* DOES NOT SEND EOT IF ZERO DELAY */
/* NOTE: GET A LOG-OFF IF NULL MESSAGE AND DELAY > 0 */
DECLARE
(ENDSMESSAGESPTR,RESTARTSPTR,COUNT,COUNTSMAX,I) ADDRESS,
CHA BYTE,
CYCLES*PERSSECOND LITERALLY '5000'; /* DEPENDENT ON HARDWARE TIMING */
MATCHSEND: FUNCTION BYTE;
FIRSTSGETBSFLAG=TRUE;
GETSCHASCHSPTR=RESTARTSPTR;
DO WHILE (CHA:*GETSCHA(0)) = GETSCHB(ENDSMESSAGESPTR);
IF CHA = NIL THEN DO; RETURN TRUE; FI
IF OCTOSOUTSREADY THEN DO; /* DON*T LOSE HIGH BAUD INPUT */
COUNT=COUNT$MAX;
CALL PUTSCHA(0,RECEIVESCH);
FI
ENDDO
IF CHA <> NIL THEN DO;
GET$CHASCHSPTR=RESTART$PTR;
DUMMY = GETSCHA(0) ;
RESTART$PTR*GETSCHASCHSPTR;
FI
RETURN FALSE;
ENDFUNCTI ON MATCHSEND;
IF OCTOSTIMEOUT = 0 THEN DO;
C0UNT$MAX=2;
END: ELSE DO;
COUNTSMAX=OCTOSTIMEOUT+1;
CALL CLEARSOCTOSOUTPUT;
CALL SENDSCH(OCTOSEOM);
RESTARTSPTR=(VALUESPTR:=FSSGET) +1 ;
FIRSTSPUTASFLAG=TRUE;
COUNT = COUNTSMAX;
DO WHILE (COUNT:=COUNT-1) <> 0 AND NOT CONSBREAK;
FOR 1=0 TO CYCLESSPERSSECOND;
IF OCTOSOUTSREADY THEN DO;
COUNT=COUNTSMAX;
CALL PUTSCHACVALUESPTR,RECEIVESCH);
IF MATCHSEND THEN DO; RETURN TRUE; FI
FI
ENDFOR
ENDDO
RETURN FALSE;
ENDFUNCTI ON RECEIVESSTRING;
/*** SYMBOL TABLE ROUTINES ***/
/* A HASH TABLE, WHICH IS AN ARRAY OF 32 CHAIN POINTERS, IS USED. */
/* EACH ENTRY IS A BLOCK WITH THE FOLLOWING FIELDS: (NO. BYTES IN FIELD) */
/* NEXT(2) , CH-PTR(2), VALUE(2), NAME(2), NAME-TEXT(8) */
/* STSFIND DOES A LOOKUP AND SETS STSENTRYSPTR AND HASHSINDEX . */
/* STSDELETE DELETES THE PREVIOUSLY FOUND ENTRY AT STSENTRYSPTR. */
/* STSCREATE CREATES AN ENTRY AT HASHSINDEX. */
/* STSADDSVALUE FILLS IN THE VALUE PTR FOR THE ENTRY AT STSENTRYSPTR */
DECLARE /* SYMBOL TABLE STUFF */
HASHSTABLE(32) ADDRESS, /*ADDRESS OF FIRST IN CHAIN OF EQUAL HASH ENTRIES*/
HASHSINDEX BYTE. /* INDEX INTO HASHSTABLE, SET BY STSFIND */
STSENTRYSPTR ADDRESS. /* ADDRESS OF AN ENTRY (BLOCK) */
STSENTRY BASED STSENTRYSPTR ADDRESS,
STSPREVIOUSSPTR ADDRESS, /* ADDRESS OF CHAIN POINTER TO CURRENT STSENTRY */
STSPREVIOUS BASED STSPREVIOUSSPTR ADDRESS, /* HASH INDEX OF PREVIOUS BLOCK */
STSCHSPTRSINDEX LITERALLY '1', /* STSENTRY(1) IS LAST CH PTR (FORM PTR)*/
STSVALUESINDEX LITERALLY '2', /* STSENTRY(2) IS THE VALUE POINTER */
STSNAMESINDEX LITERALLY '3', /* STSENTRY(3) IS PTR TO REST OF NAME */
STSNAMESOFFSET LITERALLY '6'; /* STSENTRYSPTR+6 IS START OF NAME BLOCK */
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
131
00659 1
00660 1
00661 2
00662 2
00663 1
00664 1
00665 2
00666 2
00667 2
00666 2
00669 2
00670 2
00671 2
00672 2
00673 2
00674 2
00675 3
00676 2
00677 2
00678 2
00679 3
00680 2
00681 2
00682 2
00683 3
00684 3
00685 2
00686 2
00687 1
00668 1
00689 2
00690 2
00691 2
00692 2
00693 2
00694 2
00695 2
00696 1
00697 1
00698 2
00699 2
00700 2
00701 2
00702 2
00703 2
00704 2
00705 2
00706 2
00707 2
00708 2
00709 1
00710 1
00711 2
00712 2
00713 2
00714 2
00715 2
00716 2
00717 2
00718 2
00719 1
00720 1
00721 2
00722 2
00723 2
00724 2
00725 2
00726 2
00727 2
00728 2
00729 2
00730 2
00731 2
00732 2
00733 2
00734 2
00735 2
00736 2
00737 2
00738 2
00739 3
00740 2
00741 2
00742 1
00743 1
Page 30
132
STSINIT: PROCEDURE:
FOR HASHSINDEX=0 TO LASTCHASHSTABLE); HASHSTABLECHASHSINDEX)=0; ENDFOR
ENDPROCEDURE STSINIT;
STSFIND: FUNCTI ON(NAMESPTR) BYTE:
/* IF FOUND. VALUE IS TRUE AND STSENTRYSPTR, STSPREVIOUSSPTR ARE SET */
/* IN ANY CASE, HASHSINDEX IS SET */
DECLARE
NAMESPTR ADDRESS,
(HASH,CH) BYTE,
HASHSMASK LITERALLY '1111 IB’; /* FOR 32 HASH CHAINS */
HASH=0; FIRSTSGETASFLAG=TRUE;
DO WHILE (CH:=GET$CHA(NAMESPTR)) <> NIL;
HASH=HASH+CH;
ENDDO;
IF HIGHCSTSENTRYSPTR:=HASHSTABLE(HASHSINDEX:=HASH AND HASHSMASK))=0 THEN DO;
RETURN FALSE;
FI
STSPREVI0US$PTR=.HASHSTABLE(HASHSINDEX);
DO WHILE NOT STRINGSEQUALITY(NAMESPTR,STSENTRYSPTR+STSNAMESOFFSET);
STSPREVIOUSSPTR=STSENTRYSPTR;
IF HIGH(STSENTRYSPTR:=STSENTRY) = 0 THEN DO; RETURN FALSE; F!
ENDDO
RETURN TRUE;
ENDFUNCTI ON STSFIND;
STSDELETE: PROCEDURE;
/* DELETE THE SYMBOL TABLE ENTRY AT STSENTRYSPTR */
/* BUT FIRST FREE THE NAME AND VALUE CHAINS */
CALL FREESCHAIN(ST$ENTRY(STSNAMES INDEX));
CALL FREESCHAIN(STSENTRY(STSVALUESINDEX));
STSPREVIOUS=STSENTRY;
CALL FSSFREE(STSENTRYSPTR);
ENDPROCEDURE STSDELETE;
STSCREATE: PROCEDURE(NAMESPTR);
/* CREATE AN ENTRY AT HASHS!NDEX, LEAVE STSENTRYSPTR SET */
/* VALUE PTR TO BE FILLED IN LATER BY STSADDSVALUE */
DECLARE NAMESPTR ADDRESS;
ST$ENTRY$PTR=FSSGET;
STSENTRY=HASH$TABLE(HASHSINDEX);
HASHSTABLE(HASHSINDEX)=STSENTRY*PTR;
STSENTRY(STSNAMESINDEX)=0;
CALL COPY$VALUE(NAME$PTR,STSENTRYSPTR + STSNAMESOFFSET) ;
STSENTRY(STSVALUESINDEX)=0;
ENDPROCEDURE STSCREATE;
STSADDSVALUE: PROCEDURE(STSVALUESPTR);
/* FILL IN THE VALUE PTR IN ENTRY AT STSENTRYSPTR */
/* ALSO RESET FORMPTR */
DECLARE STSVALUESPTR ADDRESS;
CALL FREESCHAIN(STSENTRY(STSVALUESINDEX));
STSENTRY(STSVALUESINDEX)=ST$VALUE$PTR;
STSENTRY(STSCHSPTRSINDEX)=ST$VALUE$PTR+1;
ENDPROCEDURE STSADDSVALUE;
STSREINIT: PROCEDURE:
/* DEFINE THE IDLE MACRO SIM = S(PS,S(RS,.)) #/
DECLARE IM DATA
(FUNSCH,LEFTSDELIM,LITSP,LITSS,ARGSDELIM,
FUNSCH,LEFTSDELIM,LITSR,LITSS,ARGSDELIM,'.',RIGHTSDELIM,RIGHTSDELIM);
FIRSTSPUT ASFLAG = TRUE;
CALL PUTSCHA(TEMPSPTR:=FSSGET,FUNSCH);
CALL PUTSCHA(0,LITSI);
CALL PUTSCHACO,LITSM);
DUMMY=ST$FIND(TEMPSPTR);
CALL STSCREATE!TEMPSPTR);
CALL FSSFREE(TEMPSPTR);
FIRSTSPUTA$FLAG=TRUE;
TEMPSPTR=FS$GET;
FOR ITEMP=0 TO LAST(IM);
CALL PUTSCHA(TEMPSPTR, IM(I TEMP));
ENDFOR
CALL STSADDSVALUE(TEMPSPTR);
ENDPROCEDURE STSREINIT;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
00744 1
00745 1
00746 1
00747 2
00748 2
00749 2
00750 2
00751 2
00752 1
00753 1
00754 2
00755 2
00756 1
00757 1
00758 1
00759 1
00760 1
00761 2
00762 2
00763 3
00764 4
00765 4
00766 4
00767 3
00768 3
00769 2
00770 1
00771 1
00772 2
00773 2
00774 2
00775 1
00776 1
00777 2
00778 2
00779 1
00780 1
00781 2
00782 2
00783 2
00784 2
00785 2
00786 2
00787 2
00788 2
00789 2
00790 2
00791 2
00792 3
00793 2
00794 3
00795 2
00796 3
00797 2
00798 2
00799 1
00800 1
00801 1
00802 1
00803 1
00804 2
00805 2
00806 2
00807 2
00808 2
00809 2
00810 2
00811 2
00812 2
00813 2
00814 2
00815 3
00816 3
00817 4
00818 3
00819 2
00820 3
00821 3
00822 2
00823 2
00824 2
00825 2
00826 2
00827 2
00828 3
00829 2
00830 2
00831 1
/#** GENERAL UTILITIES FOR SCAN AND PRIMITIVE FUNCTIONS ***/
THISSNS: FUNCTION ADDRESS;
DECLARE THIS ADDRESS;
TH1S=NSSSTACK(NSSSTACKStNDEX);
NSSSTACKSINDEX=NSSSTACKS INDEX+1;
RETURN THIS;
ENDFUNCTI ON THISSNS;
NEXTSNS: FUNCTION ADDRESS;
RETURN NSSSTACK(NSSSTACKSINDEX:=NSSSTACKSINDEX+1);
ENDFUNCTI ON NEXTSNS;
/*#* DEBUG AIDS *#*/
TRACESPRINT: PROCEDURE;
DO FOREVER;
IF (VALUESPTR:=THIS$NS) THEN DO;
CALL CRLF;
NSSSTACKSINDEX = NS$SAVES INDEX;
RETURN;
FI
CALL PR INTSSTRING(VALUESPTR); CALL PR INTSCH(5CH);
ENDDO
ENDPROCEDURE TRACESPRINT;
TURNSTRACESON! PROCEDURE;
TRACE$FLAG=SHL(TRACESFLAG,1) OR 1;
CPMSPRINT$FLAG=TRUE;
ENDPROCEDURE TURNSTRACESON;
TURNSTRACESOFF: PROCEDURE;
TRACESFLAG=SHR(TRACESFLAG,1);
ENDPROCEDURE TURNSTRACESOFF;
PROCESSSCONSBREAK: PROCEDURE;
DECLARE CH BYTE;
IF NOT STSFINDC.ATSCB) THEN DO; CALL STSCREATE(.ATSCB); FI
FIRSTSPUTASFLAG=TRUE;
CALL PUTSCHAIVALUESPTR:=FSSGET,CH:=READSCH);
CALL STSADDSVALUEIVALUESPTR);
IF CH <> ESC THEN DO; RETURN: FI
CALL PR INTSMESS(, ' TNI: S*);
IF C CH:=READ$CH) = LITST THEN DO; /* 'T */
CALL TURNSTRACESON;
END; ELSE IF CH = LITSN THEN DO; /* 'N' */
CALL TURNSTRACESOFF;
END: ELSE IF CH = LITSI THEN DO; /* 'I' */
GO TO START;
FI
CALL CRLF;
ENDPROCEDURE PROCESSSCONSBREAK;
/*** UTILITIES FOR SCAN ALGORITHM ***/
ASSNSSINIT: PROCEDURE:
/* LOAD THE IDLE MACRO; RESET THE NEUTRAL STRING */
DECLARE
CLSIM DATA
(FUNSCH,LEFTSDELIM,FUNSCHj L l T$ I , LITSM,RIGHTSDELIM),
/* RELEASE ACTIVE STRING BLOCKS, THEN SET ACTIVE TO S(SIM) */
CALL FREESCHAIN(ASSBLOCKSPTR);
AS$BLOCK$PTR=FS$GET;
IF NOSEXSVALUE THEN DO:
FIRSTSPUTASFLAG=TRUE;
FOR 1=0 TO LASTCCLSIM);
CALL PUTSCHA(ASSBLOCKSPTR,CL$IM<I));
ENDFOR
END: ELSE DO;
CALL COPYSVALUE(VALUE$PTR,ASSBLOCKSPTR);
NOSEXSVALUE=TRUE;
FI
AS$CH#PTR=ASSBLOCKSPTR+2;
/* RESET NEUTRAL STACK TO EMPTY RELEASING THE ASSOCIATED BLOCKS */
NSSSTACKSINDEX=0;
DO NEXTSARG;
CALL FREESCHAIN(ARGSPTR);
ENDDO
NSSSTACKSINDEX=0;
ENDPROCEDURE ASSNSSINIT;
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 31
133
00832 1
00833 2
00834 2
00835 2
00836 2
00837 2
00838 1
00839 1
00840 2
00841 2
00842 2
00843 2
00844 2
00845 2
00846 2
00847 2
00848 2
00849 3
00850 3
00851 4
00852 4
00853 5
00854 4
00855 3
00856 3
00857 2
00858 2
00859 2
00860 2
00861 2
00862 3
00863 3
00864 2
00865 2
00866 1
00867 1
00868 2
00869 2
00870 2
00871 2
00872 2
00873 2
00874 2
00875 2
00876 2
00877 3
00878 3
00879 2
00880 1
00881 1
00882 2
00883 2
00884 2
00885 2
00886 2
00887 2
00888 2
00889 2
00890 3
00891 3
00892 2
00893 3
00894 3
00895 4
00896 4
00897 4
00898 3
00899 2
00900 1
00901 1
00902 2
00903 2
00904 2
00905 2
00906 2
00907 2
00908 3
00909 4
00910 4
00911 3
00912 5
00913 5
00914 4
00915 4
00916 3
00917 3
00918 2
00919 1
AS*FREE$BL0CK: PROCEDURE;
TEMPSPTR=ASSBLOCKSPTR;
ASSBLOCKSPTR=ASSBLOCK;
CALL FSSFREE(TEMPSPTR);
ASSCHSPTR*ASSBLOCKSPTR+2;
ENDPROCEDURE ASSFREESBLOCK;
ASSNEXTSCH: FUNCTI ON(MOVESPTRSFLAO) BYTE:
/* RETURN THE NEXT 7-BIT CHARACTER FROM THE ACTIVE STRING */
/* ASSCHSPTR IS THE ADDRESS OF THE NEXT CHAR TO BE RETURNED */
/* OR JUST OFF THE END OF A BLOCK */
/* PAST CHARACTERS ARE REPLACED WITH 'PHI' (8-BIT NULL)*/
DECLARE
(MOVESPTRSFLAG,CH) BYTE,
OLDSBLOCKSPTR ADDRESS;
NEXT: FUNCTION BYTE:
IF (LOW(ASSCHSPTR) AND NOTSPTRSMASK) * 0 THEN DO;
CALL ASSFREESBLOCK:
IF HIGH(ASSBLOCKSPTR) = 0 THEN DO;
GO TO START;
FI
FI
RETURN ASSCH;
ENDFUNCTI ON NEXT;
/* SKIP ANY 8-BIT CHARACTERS */
DO WHILE ROL(CH:=NEXT,1); ASSCHSPTR=ASSCHSPTR+1; ENDDO
IF MOVESPTRSFLAG THEN DO;
AS$CH=PHI;
ASSCHSPTR = ASSCHSPTR+1;
FI
PFTIIRN PH *
ENDFUNCTI6n ASSNEXTSCH;
STARTSNEXTSARGUMENT: PROCEDURE(FLAGS);
/* INITIALIZE THE NEXT NEUTRAL STRING STACK ENTRY TO THE NULL STRING */
/* ALSO SET FLAGS WHICH INDICATE ACTIVE OR NEUTRAL MODE */
DECLARE FLAGS BYTE;
NSSSTACK(NSSSTACKSINDEX:=NSSSTACKSINDEX+1),NS$CH$PTR=FS$GET OR FLAGS;
NSSCHSPTR*(NSSCHSPTR AND PTR$MASK)+2;
NSSARGSBREAK=FALSE;
IF NSSSTACKSINDEX=LAST(NSSSTACK)-4 THEN DO;
CALL M0N1(9,.'NS STACK OVERFLOW S');
GO TO BDOS;
FI
ENDPROCEDURE STARTSNEXTSARGUMENT;
NSSADDSCH: PROCEDURE(CH):
/* APPEND CH TO THE ACTIVE STRING. IF NSSARGSBREAK IS FALSE, THEN */
/* NSSCHSPTR IS THE ADDRESS OF THE NEXT CHARACTER TO BE ADDED */
DECLARE
CH BYTE,
(BLOCKSPTR,BLOCK BASED BLOCKSPTR) ADDRESS;
IF NSSARGSBREAK THEN DO:
NSSCHSPTR=APPENDSCH(CH,NSSSTACK(NSSSTACKSINDEX) AND PTRSMASK);
NSSARG$BREAK=FALSE;
END; ELSE DO;
NS$CH= CH *
IF(LOW(NSSCHSPTR:=NSSCH$PTR+1) AND NOTSPTRSMASK) = 0 THEN DO;
BLOCK$PTR = NSSCHSPTR-BLOCKSLENGTH;
BLOCK,NS$CHSPTR=FSSGET;
NSSCHSPTR = NSSCHSPTR + 2;
FI
FI
ENDPROCEDURE NSSADDSCH;
PROCESSSQUOTEDSSTRING: PROCEDURE:
DECLARE (DEL IMSLEVEL,LASTSDELIMSWASSLEFT,CH) BYTE;
DEL IMSLEVEL*0:
LASTSDELIMSWASSLEFT=TRUE;
DO FOREVER;
IF (CH:=ASSNEXTSCH(MOVESPTR)) = LEFTSDELIM THEN DO:
IF LASTSDELIMSWASSLEFT THEN DO; DEL IMSLEVEL*DELIMSLEVEL+1 ; FI
LASTSDELIMSWASSLEFT* TRUE:
END: ELSE IF CH = RIGHTSDELIM THEN DO:
IF LASTSDELIMSWASSLEFT THEN DO; LASTSDELIMSWASSLEFT=FALSE;
END; ELSE DO; DELIMSLEVEL=DELIMSLEVEL-1 ;
IF DEL IMSLEVEL = 0 THEN DO; RETURN; FI
FI
CALL NSSADDSCH(CH);
ENDDO
ENDPROCEDURE PROCESSSQUOTEDSSTRING;
Page 32
134
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
00920
1
00921
2
00922
2
00320
2
00924
2
00925
2
00326
2
00927
3
00928
3
00929
4
00930
4
00931
3
00932
4
00933
4
00934
3
00935
2
00936
3
00937
3
00938
2
00939
3
00940
2
00941
1
00942
1
00943
1
00944
1
00945
1
00946
2
00947
2
00948
2
00949
2
00950
2
00951
2
00952
2
00953
2
00954
2
00955
2
00956
3
00957
3
00958
2
00959
3
00960
3
00961
2
00962
2
00963
2
00964
3
00965
3
00966
3
00967
2
00968
2
00969
2
00970
2
00971
2
00972
2
00973
3
00974
2
00975
1
00976
1
00977
2
00978
2
00979
2
00980
2
00981
2
00982
2
00983
2
00984
2
00985
3
00986
4
00987
3
00988
4
00989
3
00990
2
00991
2
00992
2
00993
1
00994
1
00995
2
00996
2
00997
2
00998
2
00999
2
01000
1
01001
1
01 002
2
01 003
2
01 004
2
01 005
2
01 006
1
Number 23
PROCESSSBEG!NSFUNCTION: PROCEDURE;
DECLARE
BLOCKSPTR ADDRESSj
(BLOCK BASED BLOCKSPTR,CH) BYTE;
IF (CH:=AS$NEXT$CHCDONTSMOVESPTR)) = FUNSCH THEN DO;
DUMMY = ASSNEXT®CH(MOVESPTR);
IF (CH:=AS$NEXTSCH(DONTSMOVESPTR)) = LEFTSDELIM THEN DO; /* NEUTRAL */
DUMMY =ASSNEXTSCH(MOVESPTR);
CALL STARTSNEXTSARGUMENT(NSSFUNSBIT);
END; ELSE DO; /* NOT A FUNCTION, JUST TWO FUN CHARACTERS */
CALL NSSADDSCH(FUNSCH);
CALL NSSADDSCH(FUNSCH);
END^ELSE IF CH = LEFTSDELIM THEN DO; /* ACTIVE FUNCTION CALL */
6uMMY=ASSNEXTSCH(MOVESPTR);
CALL STARTSNEXTSARGUMENTCNSSFUNSBIT OR NSSACTIVESBIT);
END: ELSE DO; /* NOT A FUNCTION, JUST ONE FUN CHARACTER */
CALL NS$ADDSCH(FUNSCH);
FI
ENDPROCEDURE PROCESSSBEGINSFUNCTI ON;
/*** UTILITIES FOR PRIMITIVE FUNCTIONS ***/
BINARYSTOSSTRING: PROCEDURE!N);
/« NOTE: VALUESPTR IS USED BY PROCESSSENDSFUNCTI ON */
DECLARE
N ADDRESS,
D(6) BYTE,
(I,K,NEGATIVE) BYTE;
NEGATIVE=FALSE;
I = -1 ;
IF ROLCHIGH(N),1) THEN DO;
NEGATIVE=TRUE;
N=-N:
END; ELSE IF N = 0 THEN DO;
I =0;
D ( 0) = ' 0' ;
DO WHILE N > 0;
1=1+1;
D ( I ) = (N MOD 10) + '0';
N=N/10;
ENDDO
IF NEGATIVE THEN DO; 1=1+1; D(I)='-'; FI
VALUE$PTR=FS$GET;
FIRSTSPUTASFLAG=TRUE;
FOR K=0 TO I;
CALL PUT$CHA(VALUESPTR,D(I-K));
ENDFOR
ENDPROCEDURE BINARYSTOSSTRING;
STRINGSTOSBINARY: FUNCTI ONCBLOCKSPTR) ADDRESS;
DECLARE
(BLOCKSPTR,N) ADDRESS,
(CH,NEGATIVE) BYTE;
N,NEGATIVE=0;
FIRST$GETA$FLAG=TRUE;
DO WHILE (CH:=GET$CHA(BLOCKSPTR AND PTRSMASK)) <> NIL;
IF CH = 'THEN DO;
NEGATIVE=TRUE;
END; ELSE IF (CH:=CH-'0') < 10 THEN DO;
N=SHL(N,3)+N+N+CH;
FI
ENDDO
IF NEGATIVE THEN DO; RETURN -N; FI
RETURN N;
ENDFUNCTI ON STRINGSTOSBtNARY;
CHSTOSHEX: FUNCTION(CH) BYTE;
DECLARE CH BYTE;
IF CH <= '9' THEN DO; RETURN CH-'O'; FI
IF CH < 47H THEN DO; RETURN CH-37H; FI /* CH-'A'+IO */
RETURN CH-57H; /* LOWER CASE A-F */
ENDFUNCTI ON CHSTOSHEX;
HEXSTOSCH: FUNCTI ON(HALFSBYTE) BYTE;
DECLARE HALFSBYTE BYTE;
IF HALFSBYTE < 10 THEN DO; RETURN HALFSBYTE+'O'; FI
RETURN HALFSBYTE+57H; /* 57H = 'A'-10 (LOWER CASE A-F) */
ENDFUNCTI ON HEXSTOSCH;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 33
135
01007 1
01008 2
01009 2
01010 2
01011 2
01012 2
01013 2
01014 2
01015 1
01016 1
01017 2
01018 2
01019 2
01020 2
01021 2
01022 2
01023 2
01024 2
01025 2
01026 2
01027 3
01028 3
01029 3
01030 3
01031 4
01032 5
01033 4
01034 4
01035 4
01036 5
01037 4
01038 4
01039 3
01040 2
01041 2
01042 3
01043 3
01044 3
01045 3
01046 4
01047 4
01048 5
01049 4
01050 5
01051 4
01052 3
01053 2
01054 2
01055 2
01056 2
01057 2
01058 3
01059 3
01060 4
01061 4
01062 4
01063 3
01064 3
01065 3
01066 3
01067 2
01068 1
01069 1
01070 1
01071 1
01072 1
01073 1
01074 1
01075 1
01076 2
01077 2
01078 2
01079 2
01080 2
01081 3
01082 3
01083 4
01084 4
01085 3
01086 4
01087 4
01088 3
01089 2
01090 1
Page 34
136
NUMBERSOFSARGS: FUNCTION BYTE:
/* COUNT THE NUMBER OF ARGS FOR THE CURRENT FUNCTION */
DECLARE N BYTE;
N= 1 ;
DO NEXTSARG' N=N+1; ENDDO
NSSSTACKSINDEX = NSSSAVESINDEX;
RETURN N:
ENDFUNCTI ON NUMBERSOFSARGS;
SSSMATCH: FUNCTION BYTE;
/* SUBSTRING MATCH TEST FOR SS, IN */
/* IMPLICIT INPUT: SSSCHASPTR (START SEARCH HERE), ARGSPTR (SUBSTRING) */
/* IMPLICIT OUTPUT: SSSCHBSPTR, SSSCHCSPTR (BOUNDS OF MATCHED SUBSTRING) */
/* SSSCHBSPTR IS THE CHAR BEFORE THE FIRST MATCHED CHARACTER */
/* SSSCHCSPTR IS THE LAST CHARACTER OF THE MATCH */
DECLARE
(CHA.CHB) BYTE,
RESTARTSPTR ADDRESS;
MATCHSHERE: FUNCTION BYTE;
FIRST$GETB$FLAG=TRUE;
DO FOREVER;
/* GET NEXT 7-BIT CHAR FROM SUBSTRING. IF NIL THEN HAVE MATCHED */
DO WHILE R0L(CHB:=GETSCHB(ARGSPTR>,1);
IF CHB = NIL THEN DO; RETURN TRUE; FI
ENDDO
/* GET NEXT 7-BIT CHAR FROM STRING. FAIL IF FIND 8-BIT <> PHI */
DO WHILE ROLtCHA:=GET*CHA(0),1);
IF CHA <> PHI THEN DO; RETURN FALSE; FI
ENDDO
IF CHA <> CHB THEN DO; RETURN FALSE; FI
ENDDO
ENDFUNCTION MATCHSHERE;
NEXTSSTART: FUNCTION BYTE:
GETSCHASCHSPTR=RESTARTSPTR;
DUMMY = GETSCHA(0);
DO FOREVER:
RESTARTSPTR=GETSCHASCHSPTR:
IF ROL(CHA:=GETSCHA(0).1) THEN DO;
IF CHA = NIL THEN DO; RETURN FALSE; FI
END; ELSE DO:
RETURN TRUE;
FI
ENDDO
ENDFUNCTION NEXTSSTART;
RESTART$PTR=SS$CHASPTR;
IF NULLSTEST(ARGSPTR) THEN DO; RETURN FALSE; FI
DO FOREVER;
GETSCHASCHSPTR=RESTARTSPTR;
IF MATCHSHERE THEN DO;
SSSCHBSPTR=RESTARTSPTR;
SSSCHCSPTR 3 GETSCHASCHSPTR;
RETURN TRUE;
FI
IF CHA = NIL THEN DO; RETURN FALSE; FI
/* RESTART AT THE NEXT 7-BIT CHAR */
IF NOT NEXTSSTART THEN DO; RETURN FALSE; FI
ENDDO
ENDFUNCTI ON SSSMATCH;
/*** PRIMITIVE FUNCTIONS AND PROCESSSENDSFUNCTI ON ***/
/* FUNCTIONS ARE ENTERED WITH NSSSTACKSINDEX CORRESPONDING TO FIRST ARGUMENT */
/* VALUESPTR IS PRESET TO NULLSSTRINGSPTR FOR DEFAULT VALUE */
PFSNS: PROCEDURE;
/* 'NAME STRING' S(NS,NAME,VALUE.NAME,VALUE,...) */
/* REUSES ANY EXISTING SYMBOL TABLE ENtRIES */
DO NEXTSARG; „
IF NOT st$FIND(ARGSPTR) THEN DO; CALL STSCREATE(ARGSPTR); FI
IF (ARGSPTR:=NEXTSNS) THEN DO;
CALL STSADDSVALUE(FSSGET); /* SUPPLY NULL VALUE IF NO ARGUMENT */
RETURN;
END: ELSE DO;
6ALL STSADDSVALUECARGSPTR);
NSSSTACK(NSSSTACKSINDEX)=NULLSSTRINGSPTR; /*S0 WON'T FREE VALUE*/
FI
ENDDO
ENDPROCEDURE PFSNS;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
01091
01092
01093
01094
01095
01096
01097
0109S
01099
01100
01 1 01
01102
01103
01104
01 105
01 1 06
01107
01 1 08
01109
01 1 1 o
01111
01112
01113
01114
01115
01116
01117
01118
01119
01120
01 121
01 122
01 123
01 124
01125
01 126
01 127
01 128
01 1 29
01 1 30
01 1 31
01 1 32
01 1 33
01 134
01 135
01136
01 137
01 138
01 1 39
01 1 40
01 1 41
01 1 42
01 1 43
01 1 44
01 1 45
01 146
01 1 47
01 148
01 149
01 150
01 151
01 152
01 153
01 154
01 1 55
01 1 56
01 1 57
01 1 58
01 1 59
01 1 60
01 1 61
01 1 62
01 1 63
01 1 64
01 1 65
01 1 66
01 1 67
01 1 68
01 1 69
01 1 70
01 1 71
01 1 72
01 1 73
01 174
01 1 75
01 1 76
01 1 77
01 1 78
01 1 79
01 1 80
01181
01 1 82
01 1 83
1
2
2
2
2
2
3
4
4
3
3
3
3
3
3
4
4
4
4
5
4
3
2
1
1
1
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
3
2
2
2
2
2
3
3
3
4
4
4
4
4
4
5
5
4
4
3
2
1
1
2
2
2
2
2
2
2
2
2
3
3
3
3
2
2
2
3
3
3
3
3
3
3
4
3
3
2
PFSAS: PROCEDURE;
/* 'APPEND TO STRING'
DECLARE CH BYTE;
S(AS,NAME.SUFFIX,NAME,SUFFIX,...) */
DO NEXTSARG;
IF NOT STSFIND(ARGSPTR) THEN DO;
CALL ST$CREATE(ARGSPTR):
CALL STSADDSVALUE C FSSGET);
FI
IF LOWCARGSPTR:=NEXTSNS) THEN DO; RETURN; FI
FIRST$GETA$FLAG=TRUE;
IF (CHI=GET$CHA(ARGSPTR)) <> NIL THEN DO:
PUTSCHASCHSPTR=APPENDSCH(CH,STSENTRY(STSVALUESINDEX));
PUTSCHASCURRENT$BLOCKSPTR=PUTSCHASCHSPTR AND PTRSMASK;
FIRSTSPUTASFLA0=FALSE;
DO WHILE (CH:=GETSCHA(0)) <> NIL;
CALL PUTSCHA(0,CH);
ENDDO
FI
ENDDO
ENDPROCEDURE PFSAS;
PFSSS: PROCEDURE;
/* 'SEGMENT STRING' S(SS,NAME,ARG,ARG,...) */
/* NO MORE THAN 64 ARGS */
DECLARE (ARGSNUMBER,MORESFILL) BYTE;
PUTSCHASSS: PROCEDURE(CHA);
/* SPECIAL PUTSCHA FOR SEGMENT STRING */
DECLARE
(CH BASED PUTSCHASCHSPTR,CHA) BYTE,
CURRENTSBLOCKSPTR ADDRESS.
CURRENTSBLOCK BASED CURRENTSBLOCKSPTR ADDRESS;
CH=CHA;
IF (LOW(PUTSCHASCHSPTR:=PUTSCHA$CHSPTR+1) AND NOTSPTRSMASK)
= 0 THEN DO;
CURRENTSBLOCKSPTR = PUTSCHASCHSPTR-BLOCKSLENGTH;
PUT$CHASCHSPTR=CURRENTSBL0CK+2;
FI
ENDPROCEDURE PUTSCHASSS;
IF NOT STSFIND(NEXTSNS) THEN DO; RETURN; FI
ARG$NUMBER=-1;
DO NEXTSARG;
ARGSNUMBER = ARGSNUMBER+1 ;
SSSCHASPTR = STSENTRY(STSVALUESINDEX) +1 ;
DO WHILE SSSMATCH;
GET$CHASCHSPTR=SSSCHBSPTR;
DUMMY = GETSCHA(0) ;
PUTSCHASCHSPTR=GETSCHASCHSPTR;
MORESFILL=(PUTSCHASCHSPTR <> SSSCHCSPTR);
CALL PUTSCHASSS(SSSMASK OR ARGSNUMBER); /* INSERT SEG. NUM.
DO WHILE MORESFILL;
MORESFILL=(PUTSCHASCHSPTR <> SSSCHCSPTR);
CALL PUTSCHASSS(PH I);
ENDDO
SSSCHASPTR=SSSCHCSPTR;
ENDDO
ENDDO
ENDPROCEDURE PFSSS;
PFSGC: PROCEDURE;
/* 'GET CHARACTERS' $(GC,NAME,N,S,F) */
/* IF ONLY TWO ARGS, VALUE IS LENGTH OF THE NAMED STRING */
/* IF NO FORM CALLED NAME, THEN VALUE IS NULL */
DECLARE
(GCSPTR,NSPTR.N,MARKSPTR,FORMSPTR,
CURRENTSCHSPTR,BACKUPSTO) ADDRESS,
(CH,NEGSCOUNTSFAILED) BYTE;
ANOTHERSCH: FUNCTION BYTE;
IF N = 0 THEN DO; RETURN FALSE; FI
IF (CH:=GETSCHA(0)) <> NIL THEN DO;
RETURN FALSE:
ENDFUNCTI ON ANOTHERSCH;
RETURN TRUE; FI
GCSLENGTH: FUNCTION ADDRESS;
DECLARE M ADDRESS;
M = 0:
FIRSTSGETASFLAG=TRUE;
TEMPSPTR=STSENTRY(STSVALUESINDEX);
DO WHILE (CH:=GETSCHA(TEMPSPTR)) <> NIL AND
GETSCHASCHSPTR <> MARKSPTR;
IF NOT ROL(CH,1) THEN DO; M=M+1; FI
ENDDO
RETURN M;
ENDFUNCTI ON GCSLENGTH;
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
*/
Page 35
137
01184 2
01185 2
01186 2
01187 2
01188 2
01189 2
01190 2
01191 2
01192 2
01193 2
01194 2
01195 3
01196 3
01197 3
01198 2
01199 2
01200 2
01201 2
01202 2
01203 2
01204 2
01205 2
01206 3
01207 4
01208 4
01209 4
01210 3
01211 2
01212 2
01213 2
01214 2
01215 2
01216 2
01217 3
01218 2
01219 1
01220 1
01221 2
01222 2
01223 2
01224 2
01225 2
01226 2
01227 2
01228 2
01229 2
01230 2
01231 2
01232 2
01233 2
01234 2
01235 2
01236 2
01237 2
01238 2
01239 2
01240 3
01241 3
01242 4
01243 3
01244 3
01245 2
01246 3
01247 3
01248 3
01249 4
01250 5
01251 5
01252 4
01253 3
01254 2
01255 2
01256 2
01257 3
01258 2
01259 1
01260 1
01261 2
01262 2
01263 2
01264 2
01265 1
IF NOT STSFIND(.ATSGC) THEN DO: CALL STSCREATE(.AT*GC); FI
CALL ST$AD0$VALUE!GCSPTR:=FS$GET);
NAME$PTR=NEXT$NS;
N$PTR=NEXT$NS;
SSPTR=NEXT$NS;
F$PTR=NEXTSNS;
IF NOT STSFIND(NAMESPTR) THEN DO; RETURN; FI
IF LOW(NSPTR) THEN DO; /* RETURN STRING LENGTH IF NO THIRD ARGUMENT */
MARK$PTR=0;
CALL BINARVSTOSSTRING(GCSLENGTH);
RETURN;
FI
N=STRINGSTOSBI NARY(NSPTR);
NEGSCOUNTSFAI LED=>FALSE;
GETSCHASCHSPTR, FORMSPTR=STSENTRY(STSCHSPTRSINDEX);
/* NEGATIVE COUNT NOT IMPLEMENTED */
FIRSTSPUTASFLAG-TRUE;
DO WHILE ANOTHERSCH;
IF NOT ROL(CH,1) THEN DO;
N = n-1 *
FORMSl^TR 3 GETSCHASCHSPTR;
CALL PUTSCHACGCSPTR,CH);
FI
ENDDO
STSENTRY(STSCHSPTRSINDEX)=FORMSPTR;
VALUESPTR®SSPTR;
IF N <> 0 OR NEGSCOUNTSFAI LED THEN DO; VALUESPTR = FSPTR: FI
IF LOW(SSPTR) THEN DO; /* RETURN SGC IF NO S OR F ARGS */
CALL COPYSVALUECGCSPTR,VALUESPTR:=FSSGET);
FI
ENDPROCEDURE PFSGC;
PFSIN! PROCEDURE;
/* 'INITIAL' S(IN,NAME,SUBSTRING,S,F) SIN SET TO 'VALUE' */
/* ADD... IF SUBSTRING IS NULL, THEN LOOK FOR THE NEXT NON-NULL SEGMENT */
DECLARE INSPTR ADDRESS, CH BYTE;
NAMESPTR=NEXTSNS;
ARGSPTR=NEXTSNS; /* USED BY SSSMATCH */
SSPTR=NEXTSNS;
FSPTR,VALUESPTR=NEXTSNS;
IF NOT STSFIND(.ATS IN) THEN DO; CALL STSCREATE(.ATS 1N); FI
CALL STSADDSVALUE(INSPTR:=FSSGET);
IF NOT STSFIND(NAMESPTR) THEN DO; RETURN; FI
SSSCHASPTR=STSENTRY(STSCHSPTRSINDEX);
FIRSTSGETASFLAG® FALSE;
FIRSTSPUTASFLAG®TRUE;
IF SSSMATCH THEN DO:
GETSCHASCHSPTR®SSSCHASPTR;
DO WHILE GETSCHASCHSPTR <> SSSCHBSPTR:
IF NOT ROL(CH:=GETSCHA(0),1) THEN DO; CALL PUTSCHAIINSPTR,CH); FI
ENDDO
VALUESPTR=SSPTR;
END: ELSE DO;
GETSCHASCHSPTR.SSSCHCSPTR=SSSCHASPTR;
FIRSTSPUTASFLAG=TRUE;
DO WHILE (CH:=GETSCHACO)) <> NIL;
IF NOT ROL(CH,1) THEN DO;
SSSCHC$PTR=GETSCHASCHSPTR,•
CALL PUTSCHA(INSPTR, CH);
ENDDO
FI
STSENTRY(STSCHSPTRSINDEX)=SSSCHCSPTR;
IF LOW(SSPTR) THEN DO: /* RETURN SIN IF NO S OR F ARGS */
CALL COPYSVALUE(INSPTR,VALUESPTR:=FS$GET);
FI
ENDPROCEDURE PFSIN;
PFSCR: PROCEDURE;
/* 'CALL RESTORE' S(CR,NAME) */
IF NOT STSFIND(NEXTSNS) THEN DO; RETURN; FI
InDPROCEDURE C PFSCR?‘ NDEX ’ =ST$EN tRY ‘STSVALUESINDEX)♦1 ;
138
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
01266 1
01267 2
01268 2
01269 2
01270 2
01271 2
01272 2
01273 2
01274 2
01275 3
01276 3
01277 4
01278 4
01279 3
01280 4
01281 4
01282 3
01283 2
01284 1
01285 1
01286 2
01287 2
01288 2
01289 2
01290 2
01291 2
01292 2
01293 1
01294 1
01295 2
01296 2
01297 2
01298 2
01299 2
01300 2
01301 2
01302 3
01303 4
01304 3
01305 2
01306 1
01307 1
01308 2
01309 2
01310 2
01311 2
01312 2
01313 2
01314 2
01315 2
01316 2
01317 2
01318 2
01319 £*"
01320 2
01321 2
01322 3
01323 4
01324 3
01325 4
01326 5
01327 5
01328 5
01329 6
01330 5
01331 4
01332 3
01333 2
01334 1
01335 1
01336 2
01337 2
01338 2
01339 2
01340 2
01341 1
01342 1
01343 2
01344 2
01345 2
01346 2
01347 2
01348 3
01349 3
01350 3
01351 2
01352 1
01353 1
01354 2
01355 2
01356 2
01357 1
Number 23
PFSEQ: PROCEDURE;
/* 'EQUAL' $(EQ,A, 6,0, B,C,...,B,C) */
/* OR $(EQ,A, B,C, B,C,...,B) */
DECLARE
CARGA,ARGB,ARGC) ADDRESS;
ARGA=NEXTSNS;
DO FOREVER;
IF L0W(ARGB:=NEXT$NS) THEN DO; RETURN; FI
IF LOWCARGC:=NEXT$NS) THEN DO;
VALUE$PTR=ARGB;
RETURN;
END; ELSE IF STRINGSEQUALITY(ARGA,ARGB) THEN DO;
VALUESPTR=ARGC;
RETURN;
FI
ENDDO
ENDPROCEDURE PFSEQ;
PFSGE! PROCEDURE;
/* 'GREATER THAN OR EQUAL TO' $(GE,N,M,S,F) */
/* '+8000H' IS TO MAP SIGNED HALF-RANGE ONTO FULL-RANGE INTEGERS */
IF STRINGSTOSBI NARY(NEXTSNS)+8000H >= STR1NGSTOSBI NARY(NEXTSNS) +8000H
THEN DO; VALUESPTR^NEXTSNS; RETURN; FI
VALUE$PTR=NEXTSNS;
VALUE$PTR=NEXTSNS:
ENDPROCEDURE PFSGE;
PFSNT: PROCEDURE;
/* 'NULL TEST' S(NT,NAME,S,F) */
NAMESPTR=NEXTSNS AND PTRSMASK;
SSPTR,VALUESPTR=NEXTSNS;
FSPTR=NEXTSNS;
IF STSFIND(NAMESPTR) THEN DO;
IF NOT NULL$TEST(STSENTRY(STSVALUESINDEX)) THEN DO;
- VALUESPTR = FSPTR;
FI
FI
ENDPROCEDURE PFSNT;
PFSCL: PROCEDURE(STACKSOFFSET);
/* 'CALL' S(CL,NAME,ARG,ARG,...) OR S(NAME,ARG,ARG,...) */
DECLARE
STACKSOFFSET BYTE, /* 0 IF FIRST ARG IS 'CL' -1 OTHERWISE */
LASTSARGSNUMBER BYTE. /* ARG(1ARG(LASTSARGSNUMBER) */
(CH,CHB,SEGSNUMBER) BYTE;
LASTSARG$NUMBER=NUMBER$OFSARGS-STACKSOFFSET-2;
NSSSTACKSINDEX=NSSSTACKSINDEX+STACKSOFFSET;
IF NOT STSFIND(NEXTSNS AND PTRSMASK) THEN DO; RETURN; FI
VALUESPTR= FSSGET;
FIRSTSGETASFLAG,FIRSTSPUTASFLAG=TRUE;
TEMPSPTR=STSENTRY(STSVALUESINDEX);
DO WHILE (CH:=GETSCHA(TEMPSPTR)) <> NIL;
IF NOT ROL(CH,1) THEN DO;
CALL PUTSCHA(VALUESPTR.CH);
END; ELSE IF R0L(CH,2) THEN DO;
IF (SEGSNUMBER:=(CH XOR SS$MASK)+1) <= LASTSARGSNUMBER THEN DO;
TEMPSPTR=NS$STACK(NSSSTACKSINDEX+SEGSNUMBER);
FIRST$GETB$FLAG=TRUE;
DO WHILE (CHB:=GETSCHB(TEMPSPTR)) <> NIL;
IF NOT ROL(CHB,1) THEN DO; CALL PUTSCHA(VALUESPTR,CHB); FI
ENDDO
FI
FI
ENDDO
ENDPROCEDURE PFSCL;
PFSEX: PROCEDURE:
/* 'EXIT' S(EX,DO-THIS) */
VALUESPTR=NEXTSNS;
NOSEXSVALUE=NULL$TEST(VALUESPTR);
GO TO START;
ENDPROCEDURE PFSEX;
PFSPS: PROCEDURE;
/* 'PRINT STRING' $(PS,ARG,ARG,...) */
DECLARE NOTSFIRST BYTE;
NOTSF1RST = FALSE;
DO NEXTSARG;
IF NOTSFIRST THEN DO; CALL CRLF; FI
NOTSFIRST = TRUE;
CALL PRINTSSTRING(ARGSPTR);
ENDDO
ENDPROCEDURE PFSPS;
PFSFW: PROCEDURE;
/* 'FORM WIDTH $(FW,CH-PER-LINE) */
C0NSW1DTH = STRINGSTOSBI NARY(NEXTSNS);
ENDPROCEDURE PFSFW;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
01358 1
01359 2
01360 2
01361 2
01362 2
01363 2
01364 2
01365 2
01366 3
01367 3
01368 4
01369 4
01370 5
01371 5
01372 5
01373 4
01374 3
01375 3
01376 3
01377 2
01378 2
01379 2
01380 2
01381 2
01382 3
01383 4
01384 3
01385 3
01386 3
01387 3
01388 3
01389 4
01390 3
01391 2
01392 3
01393 3
01394 4
01395 4
01396 4
01397 4
01398 5
01399 4
01400 5
01401 4
01402 3
01403 2
01404 1
01405 1
01406 2
01407 2
01408 2
01409 2
01410 2
01411 2
01412 2
01413 2
01414 2
01415 2
01416 3
01417 3
01418 3
01419 3
01420 2
01421 1
01422 1
01423 2
01424 2
01425 2
01426 2
01427 2
01428 2
01429 2
01430 2
01431 3
01432 3
01433 2
01434 1
01435 1
01436 2
01437 2
01438 2
PF$RS: PROCEDURE;
/* 'READ STRING' SCRS.PROMPT) */
/* INPUT FROM CONSOLE OR DISK */
DECLARE
(K.CH) BYTE,
NOTSCOMMENT BYTE;
NEXTSCHAR: PROCEDURE;
IF TBUFFSINDEX = 128 THEN DO;
TBUFFSINDEX=0;
IF M0N2( 20, .TFCB) <> 0 THEN DO;
CALL PRINT$MESS(.'DISK EOF $');
CH=END$OF$FILE;
RETURN;
FI
FI
CH = TBUFF(TBUFFSINDEX);
TBUFFSINDEX=TBUFFSINDEX+1;
ENDPROCEDURE NEXTSCHAR;
VALUESPTR=FS$GET;
FIRSTSPUTASFLAG=TRUE;
IF CONS IN THEN DO;
IF NOT LOWCARGSPTR:=NEXTSNS) THEN DO;
CALL PRINTSSTRINGCARGSPTR);
FI
CALL MON1(10,.CONBUF);
CALL CRLF;
K= 1 ;
DO WHILE K <= CONBUF Cl);
CALL PUTSCHACVALUESPTR,CONBUF(K:= K+1));
ENDDO
END: ELSE DO; /* DISK INPUT. */
NOTSCOMMENT=TRUE;
DO FOREVER;
CALL NEXTSCHAR;
IF CH = METASCHAR THEN DO; RETURN; FI
IF CH = ENDSOFSFILE THEN DO; C0NS1N=TRUE; RETURN; FI
IF CH = COMMSDELIM THEN DO:
NOTSCOMMENT = NOT NOTSCOMMENT;
END; ELSE IF CH >= ' ' AND NOTSCOMMENT THEN DO;
CALL PUTSCHACVALUESPTR,CH);
ENDDO
FI
ENDPROCEDURE PFSRS;
PFSPK: PROCEDURE;
/* 'PACK' HEX-TO-ASCII $(PK,HEX-STRING) #/
/* ALSO CALLED FROM PFSRO */
DECLARE (CHA,CHB) BYTE;
VALUESPTRaFSSGET;
TEMPSPTR=NEXT$NS;
FIRSTSGETASFLAG,FIRSTSPUTASFLAG^TRUE;
DO FOREVER;
/* NOTE: ASSUMES NO 8-BIT CHARACTERS OTHER THAN NIL */
CHA*GETSCHA(TEMPSPTR) ;
CHB=GET$CHACO);
IF CHA = NIL OR CHB = NIL THEN DO: RETURN; FI
CALL PUTSCHA(VALUESPTR,SHL(CHSTOSHEX(CHA) , 4) OR CHSTOSHEX(CHB))
ENDDO
ENDPROCEDURE PFSPK;
PFSUK: PROCEDURE;
/* 'UNPACK' ASCI I-TO-HEX S(UK,CH-STRING) «/
DECLARE CH BYTE;
IF LOWCARGSPTR:=NEXTSNS) THEN DO; RETURN; FI
FIRSTSGETASFLAG,FIRSTSPUTASFLAG=TRUE;
VALUESPTR=FSSGET;
DO WHILE (CH:=GETSCHA(ARGSPTR)) <> NIL:
CALL PUTSCHA(VALUESPTR,HEXSTOSCH(ROL(CH,4) AND OFH));
CALL PUTSCHA(0,HEXSTOSCH(CH AND OFH));
ENDDO
ENDPROCEDURE PFSUK;
PFSSO: PROCEDURE;
/* 'SEND TO OCTOPUS' SCSO,MESSAGE) «/
CALL SENDSSTRING(NEXTSNS AND PTRSMASK);
ENDPROCEDURE PFSSO;
Page 38
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
01439 1
01440 1
01441 2
01442 2
01443 2
01444 2
01445 2
01446 2
01447 2
01448 2
01449 2
01450 2
01451 2
01452 2
01453 2
01454 3
01455 2
01456 2
01457 2
01458 2
01459 3
01460 3
01461 2
01462 3
01463 3
01464 2
01465 1
01466 1
01467 2
01468 2
01469 2
01470 3
01471 2
01472 1
01473 1
01474 2
01475 2
01476 2
01477 2
01478 2
01479 2
01480 2
01481 3
01482 2
01483 2
01484 1
01485 1
01486 2
01487 2
01488 2
01489 2
01490 2
01491 2
01492 2
01493 1
01494 1
01495 2
01496 2
01497 2
01498 2
01499 2
01500 2
01501 2
01502 3
01503 2
01504 2
01505 1
01506 1
01507 2
01508 2
01509 2
01510 2
01511 2
01512 2
01513 2
01514 1
01515 1
01516 2
01517 2
01518 2
01519 2
01520 1
Number 23
PFSRO: PROCEDURE:
/* 'RECEIVE FROM OCTOPUS' $CRO,END-SENT INEL,S.F,EOM) */
/* VALUESPTR IS SET IN RECEIVESSTRING AND TRANSFERRED TO $R0 */
DECLARE ENDSPTR ADDRESS;
IF NOT STSF1NDC.ATSRO) THEN DO; CALL STSCREATE(.ATSRO); FI
ENDSPTR=NEXTSNS;
S$PTR=NEXT$NS;
FSPTR=NEXT$NS;
/* SET NEW OCTOPUS MESSAGE TERMINATOR, IF GIVEN */
CALL PFSPK:
FIRSTSGETASFLAG=TRUE;
IF (I TEMP:=GET$CHA(VALUESPTR)) <> NIL THEN DO;
OCTO$EOM=I TEMP;
FI
CALL FREESCHAIN(VALUESPTR);
IF RECEIVESSTRING(ENDSPTR) THEN DO;
CALL STSADDSVALUECVALUESPTR);
VALUESPTR=S$PTR;
END; ELSE DO;
CALL STSADDSVALUE(VALUESPTR);
VALUESPTR=FSPTR;
FI
ENDPROCEDURE PFSRO;
PFSDD: PROCEDURE:
/* 'DELETE DEFINITION' S(DD,NAME,NAME,...) */
DO NEXTSARG;
IF STSFIND(ARGSPTR) THEN DO; CALL STSDELETE; FI
ENDDO
ENDPROCEDURE PFSDD;
PFSAD: PROCEDURE;
/* 'ADD' SCAD,N,N, N, . . . ) */
/* ZERO OR MORE NUMERICAL ARGUMENTS */
DECLARE SUM ADDRESS;
SUM=0;
DO NEXTSARG:
SUM = SUM+STRINGSTOSBI NARY(ARGSPTR);
ENDDO
CALL BINARYSTOSSTRING(SUM);
ENDPROCEDURE PFSAD;
PFSSU: PROCEDURE;
/* 'SUBTRACT' S(SU,N,M) */
/* MUST HAVE EXACTELY TWO NUMERICAL ARGUMENTS */
CALL BINARYSTOSSTRINGC
STRINGSTOSBI NARY(NEXTSNS)-
STRINGSTOSBI NARY C NEXTSNS));
ENDPROCEDURE PFSSU;
PFSML: PROCEDURE;
/* 'MULTIPLY' SCML.N.N.N,...) */
/* ZERO OR MORE NUMERICAL ARGUMENTS */
DECLARE PRODUCT ADDRESS;
PRODUCTSi■
DO NEXTSARG:
PRODUCT“PRODUCT*STRINGSTOSBI NARY(ARGSPTR);
ENDDO
CALL BINARYSTOSSTRINGC PRODUCT);
ENDPROCEDURE PFSML;
PFSMD: PROCEDURE:
/* 'MOD' $CMD,N,M) */
/* MUST HAVE EXACTELY TWO NUMERICAL ARGUMENTS */
CALL BINARYSTOSSTRINGC
STRINGSTOSBI NARY(NEXTSNS) MOD
STRINGSTOSBI NARY(NEXTSNS));
ENDPROCEDURE PFSMD;
PFSZZ: PROCEDURE;
/* 'SLEEP' SCZZ.TENTH SEC) */
DECLARE N ADDRESS;
CALL WAITSTENTHCSTRINGSTOSBI NARY(NEXTSNS));
ENDPROCEDURE PFSZZ;
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 39
141
01521 1 PFSIO: PROCEDURE;
01522 2 /* 'INPUT-OUTPUT' PARAMETERS S(10,'0'OCTO,'T'TIMEOUT,'M'META) */
01523 2 DECLARE CH BYTE;
01524 2
01525 2 DO NEXTSARG:
01526 2 FIRST$GETA$FLAG=TRUE;
01527 3 IF (CH:=GET$CHA(ARGSPTR)) = LIT$0 THEN DO; /* 0: SET OCTO CHANNEL */
01528 3 OCTOSCHANNELSA=(GETSCHA(0) = LITSA);
01529 4 END; ELSE IF CH = LITST THEN DO; /* T: SET OCTO TIMEOUT */
01530 3 OCTOSTIMEOUT = STRINGSTOSBI NARY(ARGSPTR);
01531 4 END; ELSE IF CH = LITSM THEN DO; /* M: SET META-CHARACTER */
01532 3 META$CHAR=GET$CHAC0);
01533 4 END; ELSE IF CH = LITSP THEN DO; /* P: SET PRINT VIA CP/M */
01534 3 CPMSPRINT$FLAG=TRUE;
01535 4 END; ELSE IF CH = LITSO THEN DO; /* D: SET PRINT DIRECT (HARDWARE) */
01536 3 CPMSPRINT$FLAG=FALSE;
01537 4 FI
01538 3 ENDDO
01539 2 ENDPROCEDURE PFSIO;
01540 1
01541 1 PFSDV: PROCEDURE;
01542 2 /* 'DIVIDE' S(DV,N,M) */
01543 2 /* MUST HAVE EXACTLY TWO NUMERICAL ARGUMENTS */
01544 2
01545 2 CALL BINARYSTOSSTRING(
01546 2 STRINGSTOSBI NARY(NEXTSNS)/
01547 2 STRINGSTOSBI NARY(NEXTSNS));
01548 2 ENDPROCEDURE PFSDV;
01549 1
01550 1 PFSNB: PROCEDURE;
01551 2 /* 'NUMBER OF (FREE STORAGE) BLOCKS' $(NB) */
01552 2 DECLARE
01553 2 (BLOCK BASED TEMPSPTR,N) ADDRESS;
01554 2
01555 2 TEMP$PTR=FS$FIRSTSPTR;
01556 2 N=0;
01557 2 DO WHILE HIGH(TEMPSPTR) > 0;
01558 2 N=N+1;
01559 3 TEMP$PTR=BLOCK;
01560 3 ENDDO
01561 2 CALL BINARYSTOSSTRING(N);
01562 2 ENDPROCEDURE PFSNB;
01563 1
01564 1 PFSFS: PROCEDURE;
01565 2 /* 'FREE STORAGE' S(FS,FIRST ADDRESS,LAST ADDRESS) */
01566 2 CALL FSSINIT(STRINGSTOSBI NARY(NEXTSNS),STRINGSTOSBI NARY(NEXTSNS));
01567 2 ENDPROCEDURE PFSFS;
01568 1
01569 1 PFSVN: PROCEDURE;
01570 2 /* 'VERSION NUMBER' $(VN) */
01571 2 VALUESPTR = FSSGET j
01572 2 FIRSTSPUTASFLAG=TRUE;
01573 2 CALL PUTSCHA(VALUESPTR,'3');
01574 2 CALL PUTSCHA(0,'1');
01575 2 CALL PUTSCHA(0,LITSA);
01576 2 ENDPROCEDURE PFSVN;
01577 1
01578 1
01579 1
Pa 9 e 40 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 23
142
k
w
01580 1
01581 1
01582 1
01583 1
01584 1
01585 2
01586 2
01587 2
01588 2
01589 2
01590 2
01591 2
01592 2
01593 3
01594 4
01595 4
01596 3
01597 4
01598 3
01599 4
01600 4
01601 4
01602 3
01603 2
01604 2
01605 1
01606 1
01607 2
01608 2
01609 2
01610 2
01611 2
01612 2
01613 1
01614 1
01615 2
01616 2
01617 2
01618 1
01619 1
01620 2
01621 2
01622 2
01623 2
01624 2
01625 2
01626 3
01627 2
01628 1
01629 1
01630 2
01631 2
01632 2
01633 2
01634 2
01635 2
01636 3
01637 2
01638 1
01639 1
01640 2
01641 2
01642 2
01643 2
01644 3
01645 2
01646 1
01647 1
01648 2
01649 2
01650 2
01651 1
01652 1
01653 2
01654 2
01655 2
01656 2
01657 3
01658 3
01659 3
01660 3
01661 4
01662 4
01663 4
01664 3
01665 2
01666 2
01667 2
01668 2
01669 2
01670 2
01671 3
01672 2
/*** DISK I/O FUNCTIONS ***/
/* SEE 'BASIC I/O' ON PAGE 2 FOR GLOBALS */
SETSFILESNAME: PROCEDURE!FILESNAMESPTR);
/* EXPAND D : X . Y FORMAT TO ELEVEN CHAR FILE NAME AND SELECT DRIVE */
DECLARE FILESNAMESPTR ADDRESS, (I,CH,DRIVE) BYTE;
TFCB(0)= 0;
FOR 1=1 TO 11: TFCB CI ) =' '; ENDFOR
I,DRIVE=0; FIRST$GETA$FLAG=TRUE;
DO WHILE tI<11) AND ((CH:=GET$CHA(FILESNAMESPTR)) <> NIL);
IF CH = ':' THEN DO;
TFCB(0)=DRIVE;
1=0;
END; ELSE IF CH = THEN DO;
I =8;
END; ELSE DO;
i = I+1 ;
TFCB(I)=UPPERSCASE!CH);
DRIVE=CH;
FI
ENDDO
CALL SELECTSDRIVE;
ENDPROCEDURE SETSFILESNAME;
SETSFILE$RECORD: PROCEDURECRECORDSNO);
/* SET EXTENT AND NR FIELDS IN TFCB */
DECLARE RECORDSNO ADDRESS;
TFCB!12)=SHR(RECORDSNO,7);
TFCB(32)=RECORDSNO AND 7FH; /* SEE 'RANDOM ACCESS' IN CP/M MANUAL */
ENDPROCEDURE SETSFILESRECORD;
PFSRN: PROCEDURE;
/* 'RECORD NUMBER' $(RN) */
CALL BINARYSTOSSTRING(SHL!TFCB!12),7) OR TFCB<32));
ENDPROCEDURE PFSRN;
PFSOF: PROCEDURE;
/* 'OPEN FILE' S(OF,FILE-NAME,NEXT-RECORD-NUMBER,S,F) */
CALL SETSFILESNAME(NEXTSNS);
CALL SETSFILESRECORD(STRINGSTOSBI NARY(NEXTSNS));
VALUESPTR=NEXTSNS;
IF M0N2(15,.TFCB) = 255 THEN DO; /* OPEN AND TEST FOR ERROR */
VALUESPTR=NEXTSNS;
FI
ENDPROCEDURE PFSOF;
PFSMF: PROCEDURE;
/* 'MAKE FILE' $(MF,FILE-NAME,S,F) */
CALL SETSFILESNAME(NEXTSNS);
CALL SETSFILESRECORD!0);
VALUESPTR 3 NEXTSNS;
IF M0N2(22,,TFCB) = 255 THEN DO;
VALUESPTR=NEXTSNS;
FI
ENDPROCEDURE PFSMF;
PFSCF: PROCEDURE;
/« 'CLOSE FILE' S(CF,S,F) */
VALUESPTR=NEXT*NS;
IF M0N2!16,,TFCB) = 255 THEN DO;
VALUESPTR=NEXTSNS;
FI
ENDPROCEDURE PFSCF;
PFSDF: PROCEDURE;
/* 'DESTROY FILE' S(DF) */
CALL M0N1(19,.TFCB);
ENDPROCEDURE;
PFSWF: PROCEDURE;
/* 'WRITE FILE' S(WF,SOURCE-NAME,PAD-CH EMPTY FLAG,S,F) */
DECLARE (CH,I,WRITESSTATUS) BYTE;
STUFFSCH: PROCEDURE;
IF WRITESSTATUS <> 0 THEN DO; RETURN; FI
TBUFF(TBUFFSINDEX)= CH;
IF (TBUFFSINDEX:=TBUFFSINDEX+1) = 128 THEN DO;
WRITESSTATUS=M0N2C21,.TFCB);
TBUFFSINDEX=0;
STSENTRY(STSCHSPTRSINDEX)=GETSCHASCHSPTR; /* SET FORM PTR */
FI
ENDPROCEDURE STUFFSCH;
WRITESSTATUS.TBUFFSINDEX=0:
IF NOT STSFIND(NEXTSNS) THEN DO; RETURN; FI
GET$CHA$CHSPTR = STSENTRY CSTSVALUESINDEX)+1;
DO WHILE (CH:=GETSCHA(0)) <> NIL;
CALL STUFFSCH;
ENDDO
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
143
01673 2
01674 2
01675 2
01676 3
01677 2
01678 2
01679 2
01680 1
01681 1
01682 2
01683 2
01684 2
01685 2
01686 2
01687 3
01688 3
01669 2
01690 2
01691 2
01692 2
01693 2
01694 3
01695 3
01696 4
01697 4
01698 3
01699 3
01700 3
01701 3
01702 3
01703 4
01704 3
01705 2
01706 1
01707 1
01708 2
01709 2
01710 2
01711 2
01712 2
01713 2
01714 2
01715 1
01716 1
FIRSTSGETBSFLAG=TRUE;
IF (CH:=GET$CHB(NEXTSNS AND PTR$MASK)) <> NIL THEN DO:
F[ FOR 1=0 TO 127; CALL STUFFSCH; ENDFOR /* GUARANTEE A WRITE WITH PAD CH */
VALUESPTR=NEXTSNS;
IF WRITESSTATUS <> 0 THEN DO; VALUESPTR=NEXTSNS; FI
ENDPROCEDURE PFSWF;
PFSRF: PROCEDURE;
/* 'READ FILE' S (RF,SINK-NAME,RECORD-COUNTjS,F) (F=EOF) */
DECLARE RC ADDRESS;
IF NOT STSFIND(ARGSPTR:=NEXT$NS) THEN DO;
CALL STSCREATEtARGSPTR):
CALL STSADDSVALUE(FSSGET);
FI
RC = STRINGSTOSBI NARY(NEXTSNS);
VALUESPTR=NEXTSNS;
DO WHILE RC > 0;
RC = RC"1 *
IF M0N2C20,,TFCB) <> 0 THEN DO;
VALUESPTR=NEXTSNS;
RETURN;
FI
PUTSCHA$CH$PTR = APPEND$CH(TBUFF,STSENTRY(STSVALUES INDEX)) ;
PUTSCHASCURRENTSBLOCKSPTR=PUTSCHASCHSPTR AND PTRSMASK;
FIRSTSPUT ASFLAG = FALSE;
FOR TBUFFSINDEX=1 TO 127;
CALL PUTSCHA(0,TBUFF(TBUFFSINDEX));
ENDFOR
ENDDO
ENDPROCEDURE PFSRF;
PFSRD: PROCEDURE;
/* 'READ DIALECT' $(RD) */
/* EACH RD WILL GO TO THE NEXT META CHARACTER - */
/* OK IF NO INTERVENING MF OR OF. */
CONS IN = FALSE;
TBUFFSINDEX=128;
CALL PFSRS;
ENDPROCEDURE PFSRD;
Page 42
144
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
/*** PROCESS FUNCTION CALL ***/
01717 1
01718 1
01719 1
01720 2
01721 2
01722 2
01723 2
01724 2
01725 2
01726 2
01727 2
01728 3
01729 3
01730 3
01731 3
01732 3
01733 3
01734 3
01735 3
01736 3
01737 3
01738 3
01739 3
01740 3
01741 3
01742 3
01743 3
01744 3
01745 3
01746 3
01747 3
01748 3
01749 3
01750 3
01751 3
01752 3
01753 3
01754 3
01755 3
01756 3
01757 3
01758 3
01759 3
01760 3
01761 3
01762 3
01763 3
01764 3
01765 3
01766 3
01767 3
01768 3
01769 3
01770 3
01771 3
01772 3
01773 3
01774 3
01775 3
01776 3
01777 4
01778 3
01779 3
01780 2
01781 2
01782 2
01783 2
01784 3
01785 2
01786 2
PROCESSSENDSFUNCTI0N: PROCEDURE;
DECLARE
NAMESPTR ADDRESS,
NAME BASED NAMESPTR ADDRESS, /* HOLDS THE FIRST TWO CHARS OF NAME */
NAMESCH BASED NAMESPTR BYTE,
(BLOCKSPTR,BLOCK BASED BLOCKSPTR) ADDRESS,
(CH,FIRSTSCH,SECONDSCH) BYTE;
PFSINDEX: FUNCTION(CHCH) BYTE:
/* INDEX OF THE PRIMITIVE FUNCTION WHOSE TWO CHAR NAME IS CHCH */
/* NOTE... NAME LIST HAS SECOND CHARACTER FIRST, LIKE ADDRESS */
DECLARE
CHCH ADDRESS,
I BYTE,
PFSLI ST(40) ADDRESS INITIAL! /* ORDERED BY FREQUENCY */
736EH, /* NS */
7165H, /* EQ */
6E69H, /* IN */
746EH, /* NT */
6567H, /* GE */
7263H, /* CR */
6367H, /* GC */
7373H, /* SS */
6B70H, /* PK */
6461H, /* AD */
7361H, /* AS */
6464H, /* DD */
7573H, /* SU */
6C6DH, /* ML */
7664H, /* DV */
6672H, /* RF */
6677H, /* WF */
666FH, /* OF */
6663H, /* CF */
6E72H, /* RN */
666DH, /* MF */
6664H, /* DF */
6472H, /* RD */
646DH, /* MD */
6B75H, /* UK */
7370H, /* PS */
6F73H, /* SO */
6F72H, /* RO */
6F69H, /* 10 */
7865H, /* EX */
626EH, /* NB */
6E74H, /* TN */
6674H, /* TF */
7766H, /* FW */
6E76H, /* VN */
6C63H, /* CL */
7372H, /* RS */
7A7AH, /* ZZ */
7366H. /* FS */
7473H); /* ST */
FOR 1=0 TO LAST(PFSLIST);
IF CHCH = PFSLISTCI) THEN DO; RETURN I; FI
ENDFOR;
RETURN LENGTH(PFSLI ST); /* NO MATCH */
ENDFUNCTION PFSINDEX;
NSSSTACK(NSSSTACKSINDEX*1)“NULLSSTRINGSPTR OR NSSNULLSBEGINSEND;
DO WHILE NOT NSSFUNSMARKER; /* FIND THE BEGINNING OF THE CURRENT FUNCTION*/
NSSSTACKSINDEX=NSSSTACKSINDEX-1;
ENDDO;
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 43
145
01787 2
01788 2
01789 3
01790 2
01791 3
01792 3
01793 3
01794 3
01795 3
01796 3
01797 3
01798 3
01799 3
01800 3
01801 3
01802 3
01803 4
01804 3
01805 4
01806 5
01807 5
01808 5
01809 5
01810 5
01811 5
01812 5
01813 5
01814 5
01815 5
01816 5
01817 5
01818 5
01819 5
01820 5
01821 5
01822 5
01823 5
01824 5
01825 5
01826 5
01827 5
01828 5
01829 5
01830 5
01831 5
01832 5
01833 5
01834 5
01835 5
01836 5
01837 5
01838 5
01839 5
01840 5
01841 5
01842 5
01843 5
01844 5
01845 5
01846 5
01847 4
01848 3
01849 3
01850 3
01851 3
01852 3
01853 3
01854 3
01855 3
01856 4
01857 5
01858 4
01859 4
01860 4
01861 3
01862 3
01863 3
01864 3
01865 4
01866 3
01867 4
01868 3
IF NSSLIMlTSMARKER THEN DO; /* NO 'BEGIN' FOR THIS 'END' */
GO TO START ;
“ H ° SE NA " E 15 * T "S.ST.CK..NDEX •/
IF TRACESFLAG THEN DO: CALL TRACESPRINT; FI
/* NAME IS TAKEN FROM THE FIRST TWO BYTES */
/* OF THE FIRST ARGUMENT, REGARDLESS OF THE CONTENTS */
NAMESPTR=NSSSTACK(NSSSTAfcKSINDEX) AND PTRSMASK;
VALUE$PTR=NULLSSTRINGSPTR:
/* TEST FOR TWO CHAR FUNCTION NAME AND FIRST CHAR A-Z */
FIRST$CH=NAMESCH(2): SECONDSCH = NAMESCH(3);
IF SECONDSCH = NIL OR NAMESCH(4) <> NIL OR
FIRSTSCH < LITSA OR FIRSTSCH > LITSZ THEN DO; /* NOT A PF */
CALL PFSCL(- 1);
END: ELSE DO:
SELECT PFSINDEX!NAME(1)) OF
CALL PFSNS;
CALL PFSEQ;
CALL PFSIN;
CALL PFSNT;
CALL PFSGE;
CALL PFSCR;
CALL PFSGC; V s
CALL PFSSS; -
CALL PFSPK;
CALL PFSAD; > N.
CALL PFSAS; -> _ _ )
CALL PFSDD;
CALL PFSSU; \ --- -7 /-
CALL PFSML; ^
CALL PFSDV;
CALL PFSRF;
CALL PFSWF;
CALL PFSOF;
CALL PFSCF;
CALL PFSRN;
CALL PFSMF; --5\
CALL PFSDF; v \
CALL PFSRD;
CALL PFSMD; )
CALL PFSUK; _ m y
CALL PFSPS; /V ^--
CALL PFSSO; \^y - ^
CALL PFSRO; ^
CALL PFS10;
CALL PFSEX;
CALL PFSNB;
CALL TURNSTRACESON:
CALL TURNSTRACESOFF;
CALL PFSFW;
CALL PFSVN;
CALL PFSCL(0) ;
CALL PFSRS;
CALL PFSZZ;
CALL PFSFS;
BEGIN PRELOADED=TRUE; EXIT; END; /* ST */
CALL PFSCL!-1); /* NO MATCH, ASSUME 'CL' */
ENDSELECT
FI
VALUESPTR=VALUESPTR AND PTRSMASK;
/* RELEASE ARGUMENTS FOR THE FUNCTION WHICH WAS JUST DONE */
/* AND LEAVE NULL PTR + NS-END FLAGS IN PLACE OF THESE ARGS */
/* BUT DON'T RELEASE AN ARG IF IT IS THE VALUE */
NSSSTACKSINDEX = NSSSAVES INDEX;
DO WHILE NOT NSSLIMITSMARKER;
IF VALUESPTR <> (ARGSPTR:=NSSSTACK(NSSSTACKSINDEX)) THEN DO;
CALL FREESCHAIN(ARGSPTR);
FI
NSSSTACK(NSSSTACKSINDEX)=NULL$STRINGSPTR OR NSSNULLSBEGINSEND;
NSSSTACKSINDEX=NSSSTACKSINDEX+1;
ENDDO
/* SEE IF THIS ASSBLOCK CAN BE RELEASED */
IF (LOW(ASSCHSPTR) AND NOTSPTRSMASK) = 0 THEN DO;
CALL ASSFREESBLOCK;
END; ELSE IF (ASSCH = NIL) AND (HIGH(ASSBLOCK) > 0) THEN DO;
CALL ASSFREESBLOCK;
FI
Page 44
146
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
01869 3
01870 3
01871 3
01872 3
01873 3
01874 4
01875 3
01876 4
01877 5
01878 5
01879 6
01880 5
01881 5
01882 5
01883 5
01884 4
01885 5
01886 5
01887 6
01888 5
01889 5
01890 4
01891 3
01892 2
01893 1
01894 1
01895 1
01896 1
01897 1
01898 1
01899 1
01900 2
01901 2
01902 2
01903 2
01904 2
01905 2
01906 3
01907 2
01908 1
01909 1
01910 2
01911 2
01912 1
01913 1
01914 1
01915 2
01916 2
01917 2
01918 2
01919 2
01920 2
01921 3
01922 2
01923 2
01924 2
01925 2
01926 2
01927 2
01928 3
01929 2
01930 2
01931 2
01932 3
01933 3
01934 4
01935 4
01936 4
01937 3
01938 2
01939 1
01940 2
/* PROCESS THE VALUE CHAIN */
NSSSTACKSINDEX = NSSSAVESINDEX-1;
NS$ARG$BREAK=TRUE;
IF VALUE$CH( 2) = NIL THEN DO:
CALL FREESCHAIN(VALUESPTR);
END: ELSE DO:
IF NSSACTIVESFLAG>0 THEN DO; /*LINK VALUE CHAIN TO HEAD OF ACTIVE*/
BLOCKSPTR=VALUESPTR:
DO WHILE HIGH(BLOCK) > 0; /* FIND END OF VALUE CHAIN */
BLOCK$PTR=BLOCK;
ENDDO
BLOCK=AS$BLOCK$PTR;
AS$BLOCKSPTR=VALUESPTR;
ASSCHSPTR=AS$BL0CK$PTR+2;
END: ELSE DO: /* ADD VALUE TO END OF CURRENT (NEUTRAL) ARGUMENT */
FIRST$GETA$FLAG=TRUE:
DO WHILE (CH:=GET$CHA(VALUESPTR)) <> NIL;
CALL NSSADDSCH(CH);
ENDDO
CALL FREESCHAIN(VALUESPTR);
FI
FI
FI
ENDPROCEDURE PROCESSSENDSFUNCTI ON;
/*** INITIALIZATION AND SCAN LOOP ***/
DECLARE CH BYTE;
PRESETSATIN: PROCEDURE:
IF NOT STSFIND(.ATS IN) THEN DO; CALL STSCREATE(.ATS IN); FI
CALL STSADDSVALUE(VALUESPTR:=FSSGET);
FIRST$PUTASFLAG=TRUE;
ITEMP=2;
DO WHILE I TEMP <= TBUFF(O);
CALL PUTSCHA(VALUESPTR,TBUFF((I TEMP:=ITEMP+1)-1))J
ENDDO
ENDPROCEDURE PRESETSATIN;
PRrQrTtnpiuPQ 1 PRflf'Fni irf ■
DEFAULTSDRiVE.PREVIOU&SDRIVE,CURRENTSDRIVE=M0N2(25,0);
ENDPROCEDURE PRESETSDRIVES;
IF DEADSSTART THEN DO;
DEADSSTART=FALSE;
TRACESFLAG=0;
ASSBL0CKSPTR=0;
FSSFIRSTSPTR=0;
TEMPSPTR=FBASE;
IF TFCB(17) = 5EH THEN DO; /* 'ACT FILE HH' HH=HEX PAGE NO. BEYOND FS */
TEMP$PTR=256*(DOUBLE(SHL(CHSTO$HEX(TFCB(18)),4) OR CHSTOSHEX(TFCB(19))));
FI
CALL FSSINIT(.MEMORY,TEMPSPTR);
CALL STS I NIT;
CALL STSREINIT;
NULLSSTRINGSPTR=FS$GET;
FOR NSSSTACKSINDEX=1 TO LAST(NSSSTACK);
NSSSTACK(NSSSTACKS INDEX)=NULLSSTRINGSPTR OR NSSNULLSBEGINSEND;
ENDFOR
CALL PRESETSDRIVES;
IF TFCB(1) <> ' ' THEN DO; /* DISK INPUT */
CALL PRESETSATIN:
IF M0N2(15,.TFCB) <> 255 THEN DO;
CALL SELECTSDRIVE;
CONS IN = FALSE;
TFCB(32)=0;
FI
FI
END; ELSE IF PRELOADED THEN DO;
PRELOADED = FALSE;
CALL PRESETSDRIVES;
01941 2 CALL PRESETSATIN;
01942 2 CONS IN=TRUE;
01943 2 FI
01944 1
01945 1 CALL ASSNSSINIT;
01946 1
01947 1 DO FOREVER;
01948 1 IF (CH:=ASSNEXTSCH(MOVESPTR)) = LEFTSDELIM THEN DO;
01949 2 CALL PROCESSSQUOTEDSSTRING;
01950 3 END; ELSE IF CH = ARGSDELIM THEN DO:
01951 2 CALL STARTSNEXTSARGUMENT(NSSARGSFLAG);
01952 3 END; ELSE IF CH = FUNSCH THEN DO;
01953 2 CALL PROCESSSBEGINSFUNCTI ON;
01954 3 END: ELSE IF CH = RIGHTSDELIM THEN DO;
01955 2 CALL PROCESSSENDSFUNCTI ON;
01956 3 END: ELSE DO:
01957 2 CALL NSSADDSCH(CH);
01958 3 FI
01959 2 ENDDO
01960 1 EOF
NO PROGRAM ERRORS
Number 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
147
SAM 76 — Additional comments
Dear Jim:
I just got around to reading your issue 10, volume 2, and
was pleased to see the article by Frits Van Der Wateren
which describes an implementation of Strachey's GPM for the
6 800.
The first purpose of this letter is to | | ||
point out to the relatively uninitiated | j GP1 - SAM76 | |
that the SAM76 language, described in ||_[|
your first issue of volume 3 has its
roots in GP1, and that the structure and philosophy are
virtually identical between the two languages.
II II The main difference between the two
II Mimicking || languages is the scope of available
|J_II resident functions, as well ascertain
features of SAM76 whuch enable precise
user definition in the SAM76 language of functions which
might a Isa be defined in terms of assembly language
instructions - in other words "exact mimicking capability".
This feature is important to permit portability or
transferability of user programs or, as I prefer to call
them, scripts. Should some user script make use of a
function not resident in some one else’s SAM76 interpreter,
it is relatively simple to create a user defined function
identical in its functioning to the resident function
originally used-
II 11 A version of the SAM76 language coded for
| |SAM76 - 6800 | j the 6800 is in process of development by
11_LI the "notorious" Wayne Loufbrow youngster;
it is expected that this version will be
functionally identical to the 80 80/Z80 implementation, thus
permitting absolute transferability of user scripts.
The second purpose of this letter is to
respond to some queries from users as to
the problem of formatting user script for
appearance and legibility, and yet not
cause these formatting characters to
become part of the evaluation process.
| Addendum to |
| SAM 76 |
| description |!
J_1
Because of the celerity with which you published the
description of the SAM76 language, I was not able to make
the appropriate addition which responds to thus problem;
thus addition is described below, as it will appear in the
forthcoming "SAM76 language Handbook" •
The table under the heading "Quoting or Protection" on page
20 should t>e ammended by the addition of the "IC" warning
character as illustrated by the excerpt shown below.
AS
1
77
Argument separator
QC
0
100
Quote
single character
IC
140
Ignore
single character
The
following
specification
for thu. s warning
should be concatenated, with scissors and glue, at the end
of the SAM76 language description just ahead of the birds on
page 22 of your magazine.
SIERRA DIGITAL’S PDP8 X8
CROSS ASSEMBLER SERIES
News Release Received: 77 Dec 30
Sierra Digital Systems has announced the addition of four new
microprocessor cross-assemblers to its X8 cross-assembler series for the
Digital Equipment Corporation PDP8 mincomputer. The X8 series
cross-assemblers now cover the Z80, 1802, SC/MP and 8048 micro¬
processors in addition to the previous 6502, 6800, 8080, F8 and 2650
version.
By using an X8 series cross-assembler, assembly language programs
are converted into object code which may t>e loaded into a microproces¬
sor system, or put into ROM of PROM memory. X8 cross-assemblers
feature a Universal Assembler Format of common assembler directives
and techniques. This standardization of features combined with a
quantity discount schedule makes the series especially attractive to
users of more than one microprocessor type. New special package offers
at very substantial discounts are available to Educational Institutions
for microprocessor course development.
Sierra Digital's X8 cross-assemblers run in 8K words of memory
under the OS/8 operating system. The X8 assemblers are written in
PDP8 assembly language to provide very fast operation and minimum
memory requirements. Pseudo-ops and runtime options provide for
conditional assembly and extensive listing control. Generated object
code may be output in the microprocessor's standard loader format, or
BNPF for ROM generation.
Each cross-assembler is priced at $400 and distributed in PDP8
binary format on paper tape, Dectape, or Dec floppy diskette. Source
files are also available for an additional $250. Sierra Digital Systems
is located at 13905 Rancheros Drive, Reno, Nevada 89511,
(702) 329 -9548.
II II
Ignoring 11
I | next character | j
II _LI
circumstances these
expressions, and be
deleted in the scanner.
Oftentimes the user wishes to arrange
his script for convenient legibility
using "nulin", "tabs" or other
characters; this is strictly for
formatting purposes. Under normal
characters will be part of the
returned in the value string unless
Oie way of achieving this is to place these characters in
unused arguments of primitives such as the third argument of
an "os" expression. This could be a problem if at some later
time the additional unused arguments acquire a purpose.
Under initialized conditions the . character is used to
signify that the immediately next ensuing character is to hie
deleted in the scanner.
Another bright youngster, Karl Nicholas,
pointed out to me that expression "k"
under < sham > on page 23 was
unnecessarily complicated, and suggested
the following simplification which after
being checked out showed the correctness of hiis observation:
< k >
%pt,, (l)/%i/!lll/
Final
| | erratum | |
II_LI
| | Closing | |
I | comments | |
II _LI
Plaudits and bouquets to your staff wlio
did a great job of laying out in an
esthetic and artistic manner the rather
complicated material you received from
me-
I hope that the growing body of users of the SAM76 language
will contribute algorithms and scripts to your pages, and in
that manner provide an escape from the "liasic" syndrome-
Cordially,
Ancelme Roichel
148
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 23
Dr. Dobbs louRNALof
COMPUTER
(Calisthenics f) Orthodontia
Running Light Without Overbyte
Number 24 April 1978 Volume 3, Issue 4
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
List Processing Unravelled: Pointers, Chains, Rings and Trees J. M. Terry 4
Exit This Reviewer Jef Raskin 19
DDJ’s Reviewer puts his mouth where his money is
SOFTWARE
The Oznaki “Life” Harvey A. Cohen 10
An interactive version for the Poly 88
AIK Debugger for the Z-80 Les Hancock 12
A Line-Oriented PILOT Editor David J. Morgan 22
ACT: An 8080 Macroprocessor Alex Cecil 27
Assembly listing ofPL/M version published in previous DDJ
© David Dameron 1979
UNIX FOR THE 8080
Dear Jim, Received: 78 Feb 17
I’ve been bitten by the bug. The computer bug, that is. Two
years ago I literally stumbled into a computer for the first
time. And —BAAM!! Now I own one. And it’s continually
expanding, taking big bytes out of my wallet.
I’ve always wanted a computer that would do what the
11/70’s would do: control everything, and be easy and fun to
use. Until recently I couldn’t have begun to do that. But after
a summer with an 11/70 and Bell Lab’s Unix, I might just be
able to.
Exactly what I want my IMSAI to do is tough to say, but
here goes: EVERYTHING. More precisely, I want it to sup¬
port several terminals on a time sharing basis, and time share
with the same benefits Unix provides. The computer should be
able to perform processes without my supervision, and poll
many inputs and take actions on its own when required. I plan
to someday have it running my house, from the toaster to the
alarm clock to the security devices. Sounds incredible, but
when completed, it should be fantastic.
Anyone who has worked on Unix knows sort of what I
have to do. But for those who don’t, a short explanation.
Everything the computer has to do will be kept on floppy disk
and accessible by the computer. The two terminals (soon
three) will interrupt the computer for input, and when a line is
complete, it will be put into the process table. When the com¬
puter comes to this command, it will load it from the disk, and
enter it again into the process table to be executed in due
time. (The terminal is then free to be used again, and can have
more than one process running under its name at any one
time.) Each process in the table will be given equal amounts of
the computer’s time, say 1/10 second apiece. When a process
is complete, it will jump to a routine and have its name re¬
moved from the table. In between processes, the computer will
poll predefined input ports to see if anything has come up and
needs to be dealt with, like a burglar, or a process that has
been ‘sleeping’ for a while and needs to be awakened. Each
process would have its own stack and storage area for its regis¬
ters when another process is being executed. Also included in
the shell (a Unix word meaning the part of the computer pro¬
gram that oversees all of these actions, and regulates time)
would be such luxuries as piping, terminal to terminal conver¬
sation, and the old late night weapons, enable and disable
(terminals); However, it is important to remember that the
program will not have any assemblers, editors, or languages in
it. Everything will be kept on disk and only loaded when
needed. This allows for great flexibility, as the control for any
piece of hardware can be loaded on the disk, and not take up
valuable RAM.
This version of Unix will give my micro (and yours too!)
part of the power that minis and macros have, and make it
much more useful around the house. Aside from the questions
I’m about to ask, the only major problem will be the organiza¬
tion. It will be very easy to get tied up in jumps and loops and
calls. It will have to be very efficient on both RAM and operat¬
ing time (its going to run slow anyway.) If I take my time
about it and think it through completely before I begin to
write, it shouldn’t be very difficult.
There are some problems I can already forsee;
1) The 8080 has eight interrupts (or restarts) at its disposal.
I would like more. Anybody know how?
2) In order to conserve RAM, each program on disk will
have to be entirely relocatable. The best method I have
thought of yet is to insert before each addressing com¬
mand one of the unused hex bytes. While loading, when
the computer comes across this byte, it will adjust the
following address by the amount the new SA is apart
from the base SA, and leave out the flagging command
when it loads it into RAM. If someone has a better idea,
let me know.
3) As the operating system stands now, every process will
be given equal time. Is it worthwhile to set up a priority
system so that important software can run faster than
other software?
4) Should I use the Z80 instead of the 8080? The Z80
would clear up some relative addressing problems, but
leaves no unused commands to use as a flag in the relo¬
cate operation. Anybody who can convince me in either
direction wins my thanks.
5) What should I call it? Unix for the 8080? Trivial question.
6) And finally, is anybody interested in such a program?
Anybody want to make a few suggestions?
In case you’re interested in what kind of system I have, it
consists of an IMSAI 8080, 32K RAM, IMSAI PIC board
w/programmable interrupts, IMSAI MIO board, two Poly¬
morphic video displays w/keyboards, a Peripheral Vision
Floppy Disk & interface, a high speed dot matrix printer,
Cromemco’s analog I/O w/ two joysticks, an optical papertape
reader, and lots of software (tank game, Star Wars game, HAM
interface, theatrical lighting control, etc. all of my own
writing).
I plan to spend this next summer writing Unix for the 8080
and associated programs. I’d like to hear from anybody on this
program, especially anyone from the Delaware area (where I
live), or the Northwest Connecticut area where I go to school.
Keep up the good work at DDJ,
Pierre duPont
Salisbury School
Salisbury, CT 06068
We’re interested in such a program and we’ll be happy to
publish suggestions and ideas pertinent to your project...
and maybe you ’ll send us the results. Happy coding! -TRW
STAR WHA-A-A-T?
Gentlemen: Received: 78 March 9
Long, long ago in a galaxy far, far away, there was bom a
new product line of computers. The company was an estab¬
lished retail outlet starting amidst strong competition, but this
line had an edge over most others: it was prebuilt and tested.
This company has had its complement of renegades. Unfor¬
tunately the renegades occupied the big offices with the long
titles on the doors. These outcasts secreted away documents
on a space satellite. What documents you ask? All documents
on Hardware and Software. Yes friends, it is indeed a crime.
And what’s worse - the satellite came crashing down to Earth!
Already the renegades are being hunted down by the DETH
STAR. (Documentation in Entirety, Truth, 7/onesty), con¬
trolled by General Competishun. This Texas based, handy
dandy radio hut had better get off its AScii before Darth
Vector points his blinking cursor and erases you.
Signed, 4730 Cloister Ave. NW
Jeffrey Greek Canton, Ohio 44709
O. B. 1
(Overwrought and befuddled)
Number 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 3
151
POINTERS, CHAINS, RINGS &TREES
BY J. M. TERRY
P. 0. Box 3945
Lubbock, TX 79412
There is more to learning programming than the memoriza¬
tion of instruction sets or statement types. A distinction is
often made between two different sorts of skill acquisition,
“horizontal” and “vertical”. For instance, learning BASIC
as a first language is “vertical”. After that, it takes a “horizon¬
tal” effort for the programmer to leam how expressions are
written in FORTRAN. It takes a different kind of effort
to leam the use of the ALLOCATE and FREE statements
in PL/1 because there are no equivalent statements in BASIC.
When we acquire new concepts, a “vertical” effort is needed.
Most of the following concepts are beyond BASIC. The
steps aren’t difficult, but are definitely “vertical”.
Sooner or later, we are going to need powerful, elegant
ways to handle records. Those of us interested in robotics,
languages, and various other Artifical Intelligence (AI) appli¬
cations will want to connect information in complicated ways.
Systems buffs will want to manipulate individual programs
(tasks) as objects. Business software certainly can make use
of efficient record handling.
Pointers
From assembler language on up, data items are associated
with names. For instance, when a variable is assigned a value,
that value is put in the location with that name. Thus,
LETS= 12
in BASIC means that the place named “S” is to contain “12”.
When the program is loaded, the variable’s name is equivalent
to its address. If, in this BASIC, variables are eight bytes long,
then the eight bytes representing “S” are “pointed to” by
some address. Individual instructions may use different con¬
ventions for arriving at it, but all instructions referring to “S”
must reference this address. Notice that two bytes is always
the maximum needed to point anywhere inside the addressing
range of a 64K MPU. So, “S” is the same as some two-byte
address. If “SOCIAL_SECURITY” had been used instead of
“S”, its equivalent address would still be two bytes.
Consider this array:
DIM ALPHA(5)
This defines five strings of eight bytes each in our BASIC. We
want to sort them using a bubble-sort. If the first of a pair
of values is larger than file second, we save the first, move the
second to the first’s position, and put the saved value in the
second position, thus swapping the values. In this way, we pass
through all four pairs repeatedly until none are swapped.
The smaller values will “bubble” up to their proper places.
Notice that every time we swap a pair we must move eight
bytes three times. Now, suppose that we had the addresses
of the eight-byte strings in another array. We might construct
an assembler program which referenced the strings using
this address array. We could perform the sort on the address
array. Each ‘swap’ would involve just two bytes for each of
the three moves, instead of eight bytes for each move (Fig. 1).
There are many other powerful uses of pointers, but these
will do for what follows.
Fig. 1: Sorting Using Record Addresses
APPRfSS KFCa/tOS
TABLE
A. Jones’ record should come before Smith's.
B. Move'Addrl'to C. Move'Addr2' D. Restore current
SAVE to previous pointer from
pointer SAVE
E. Pointers to the records are now in the correct order. The records
themselves have not been moved.
->
rOUJTE/t
• ..->■
Move o fee avow
Memory Management
There are many times when it is desirable to postpone
defining the location of data in memory. Suppose you want
to write a general routine for updating personnel records, but
each job description uses a different format and size, because
each involves different details. You have hopes of using
some of the memory for interactive programs. If you allow for
the largest record all the time, it may mean that certain
programs will have to stay on peripherals to be loaded when
needed, slowing the system. You would like a better way.
If your operating system has a memory-manager, then all
you have to do is wait until the storage to hold a record is
needed. When it learns the size needed, your program can
pass this information to the memory-manager. A pointer
will be returned indicating where the allocation of memory
begins. There is a second, complementary function of the
memory-manager: he must be able to free memory as well
as allocate it, or, sooner or later, he will run out.
Memory-managers are used whenever allocation is post¬
poned until the program is actually executing. In addition
to its importance in processing of variable-length records,
this is desirable or necessary for recursive programs, inter¬
active interpreters, loaders, and lists. A list, by the way, is
a data set whose size can change during program execution.
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
V
152
Chains
When we interact with our systems through terminals, we
say we are processing in real-time. This is contrasted with
batch processing, in which a procedure is first defined com¬
pletely, then executed. Systems with which people interact
have fewer uses for which memory can be defined when they
are loaded than batch programs do. An interactive program
may not leam what memory it needs until some point in the
interaction with the user.
In many systems it is better to process requests on a “first
come, first served” basis. When a terminal interrupts an
ongoing task, its request is not processed immediately. Instead,
a very short routine is invoked which saves the request. The
processor then returns to the interrupted task. When this task
is finished, the next request is begun. These requests are being
stored in a First-In-First-Out (FIFO) queue. The “enqueuing”
algorithm allocates enough space for the request and its para¬
meters (Fig. 2a). The pointer to the new allocation is stored
in the FORWARD field of the element pointed to by
LATEST. This stored pointer links the allocation. Then the
new allocation’s pointer is stored in LATEST to make finding
the end easier.
When the current task is finished, it is time to de-queue a
request. CURRENT points to the information for the request
just finished. The FORWARD field of the element that
CURRENT points to indicates the information for the next
request. We are through with the current element. We move its
FORWARD field to SAVE. The contents of CURRENT are
passed to the memory-manager in a free-memory call. SAVE
is moved to CURRENT. This pointer is passed to the request
handler, which begins the task specified in the data element
pointed to (Fig. 2b).
If we didn’t compare CURRENT and LATEST, we wouldn’t
know if FORWARD contained a pointer or meaningless
garbage. Besides, how do we know if the queue is empty? A
null value for pointers simplifies everything. This could be
anything, but “0000” (hexadecimal) or some address in ROM
might do for an MPU system. It is easy to remember that
zeroes are null, and since low memory often is reserved for
interrupts, it isn’t likely that the ability to allocate from that
address will ever be missed. Whenever an element is added to
the end of a chain, its FORWARD pointer should be set to
NULL. The handling routines can easily tell when a list is
empty or when an end is reached by testing for NULL.
Fig. 2: FIFO Queue Manager
chained requests
newly allocated
and initialized
request element
A. Enqueue —Immediate request handling —create new request
element and store request in it.
B. De-queue—Move
pointer to new
element into
FORWARD field of
latest element, then
to LATEST pointer
The list described in Figs. 2a and 2b is called a one-way
linked list, or a one-way chain. The links are the FORWARD
fields. We used LAST to point to the latest entry, but that
is not strictly necessary. As long as we know where the chain
starts, we can advance, link by link, until a NULL indicates
the end.
Often we will want to insert or delete in the middle of
a chain. For instance, we may be using a chain to hold data
we wish to keep in alphabetical order. To search, we follow
the chain out link by link, comparing the key field of each
element with the name to be added (Fig. 3a). The pointer
returned with the allocation for the new element must be
stored in the element preceding the inserted element. We don’t
know which element that will be until we find a key field
with a higher sort value (that is, a key later in the alphabet)
than the name to be inserted. Therefore, we must save a
pointer to the last element every time we advance another
element. If each element contains a BACKWARD pointer,
search and insertion is simplified (Fig. 3b). This structure is
called a two-way linked list, or two-way chain, naturally
enough.
Fig. 3a: Insertions
->
[ F-ert
9
*
%
c
•
1
rC<**K
'a//.
OCO-Tl c
A. Insertions in a
one-way chain
Number 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
153
Deletions are similar to insertions, only backwards. Pointers
are altered to point around the deleted element. A pointer to
the deletion must be passed to the memory-manager in order
to free it; otherwise that allocation can’t be used again (Fig.
4a, 4b).
g ACXWAtP '•
■ Fe>A wA HO
BAc wuSA/eO
Fo#iaja4 P
FctwAAD -
•&ACK hjAXP
'~-8AtKU>AAP
Zta. to.
£
I SAVt
SAVt
POlUTtft
TO
A4/4/\M<Sfye’>
FOFWAAO
BACFiaJAAP
$e/e t(<f
Sara.
pR ft sesvict)
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
Rings
There are times it is more convenient not to have an end in
a chain. If the (null) last element of a chain is linked to the
first, a circular list, or ring, results. Suppose you are designing
an operating system to support up to sixteen terminals for
computer-assisted instruction (CAI) applications. You need
information on each user currently logged on the system.
You want your monitor to poll each terminal in turn, but
only if it is logged on. Simply let the user data reside in a
circular list. Each LOGON procedure will insert an element
describing terminal and user, and each LOGOFF will delete
the proper element. When a user surrenders MPU control,
polling will proceed in one direction. The CURRENT pointer
is the only pointer needed by the polling routine. It always
points to the data for the next terminal to be handled.
Two-way circular lists are especially nice in FIFO queue
management. Instead of chaining device requests and holding
two pointers (or searching out to the chain end to make
additions to a chain), we may build a ring from a fixed
CURRENT element in one direction (Fig. 5). When the
CURRENT element is deleted, the next element appears from
the other direction.
Fig. 5: 2-way FIFO Ring
1 sA/e
C. Current request
processing is finished
D. Next request is selected;
request just finished is
then freed
Trees
If an element contains more than one link (not counting
backward pointers), a tree structure results. The tree’s data
elements are called nodes. The starting node is called the
root-node (see Fig. 6). In moving within a tree, down means
moving away from the root-node towards peripheral nodes,
and up means moving towards the root-node. This is, perhaps
unfortunately, exactly the opposite of nature’s convention.
A. Ring before
interrupt
poiMteA limk
pa-ta A
B. New request
enqueued
Fig. 6
Number 24
Or. Oobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 7
155
However, as in real trees, the most peripheral nodes are called
leaves or leaf nodes. A “family tree”, such as you might have
in an old family bible, has this structure. The leaves are the
latest generation. Not surprisingly, the higher nodes of a tree
are called parents and are said to have children or descendant
nodes. A subtree refers to some parent node and its
descendants.
Moving down a tree involves making decisions; moving up
simply means remembering where you came from. CAI
routines often use trees. A node representing a question and
its answers is linked to other nodes. The choosing of one of
the answers causes a particular descendant question to be
referenced. Another subtree from this node is selected in the
same way. This continues until the user reaches a leafnode.
Different students might be asked entirely different questions,
except for the first root-node question, of course.
Storage and retrieval using a tree can be very fast, especially
for large data bases. This is because fewer tests are required
in searching. If every node has no more than two descendants,
a single test may narrow the search to half of the remaining
nodes. Trees are useful for managing symbol tables, efficient
use of diskette storage, and maintaining ordered data which
is constantly being changed. The many uses of trees really
deserve separate elaboration.
Other Stuff
It is often better for list elements to contain a pointer to
data instead of the data itself. If the data to be linked is
already in memory, just allocate enough space for linkage
pointers and a data-pointer, insert this element in the list,
and store the address of the data in the data-pointer. This has
the advantage of allowing several lists to reference the same
data, thus saving the duplication of data and conserving
memory. Carrying this idea one step further, each link may
contain a key. Several different sorts of key can be referenced
in several lists. Suppose an art store wishes to be able to
reference a customer file by customer name and account
number, and also wants to be able to keep track of which
customer had purchased any particular work of art. Lists for
names, ID’s, and sold artworks could be maintained in order
to reference pointers to information on the customer they
match. Such a referencing scheme for JOHN DOE, whose
ID is 99M999, and who is the owner of two works catalogued
P801 and Q003, is shown in Fig. 7. The lists from which the
links came could be chains, trees, rings, or compounds of these.
Fig. 7
Multiple References to the Same Data
Using Several Lists
It may not be easy to apply all of these ideas immediately
in your own systems. However, even if you are just learning
BASIC, take heart! There are a few tricks that will carry over.
Remember the bubble-sort? A one-dimensional array (a
vector) can be used to store index values to another array
which contains the records to be sorted. Swap the indices
in the first array instead of moving the data. After the sort,
the first item will be in some position in the data array, and
that position will be indicated by the first element of the
first, index, array. Similarly, the second element in the index
array will indicate the position of the second item in the sort
sequence, and so on (Fig. 8).
Fig. 8
A _
51AITH
z -
-
JO/dE S
3-
ta yl&R
4 "
--^
4 BEL
1 —
4"
v 77
5>A1 IT hi
'JPAJE 5
3 —
1 -
A
T AY LC? K
3-
ABEL
At=tek soar
Sorting Using Subscripts
Now, with all of these new tools, you should be just about
ready to start designing that great new system that’s been in
the back of your mind all these months.
Happy linking!
MAILING LIST PACKAGE FOR NORTHSTAR
News Release Received: 78 Feb 22
The Comprehensive Mailing List Program Package #ML-
1NS, is a modular program set which enables the user to start
and effectively maintain one or more mailing lists. Operations
include: Add, Delete, Search, Sort, Auto-Sort, and Sequential
Printout. Features include: user-selectable defaults for ease
of entry, user-selectable number of labels across page for
different printers and label sheets, and user-selectable 3 or 4
line address for each independent entry. The program set is
written for convenience and ease of use. Available with
complete documentation and North Star diskette (SWTPC
version available soon) for only $25 PPD. Documentation
package only is $4.50 PPD, fully refundable with order for
diskette. Order from: Williams Radio and tv, inc., computer
Division, 2062 Liberty Street, P. 0. Box 3314, Jacksonville,
FL 32206;(904)358-3707.
Page 8
156
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Number 24
»*#**#**»»»»»»»##*#»»**#####»##»###*#*#########*»»»»»»»»»»»»»»»»»»»»»*##»»******»»*************»»****»******»******»»'
THE OZNAKI "LIFE"
An interactive version of LIFE for the POLY-88 VDM
INTRODUCING THE NAKI CONCEPT FOR TV GRAPHICS
BY HARVEY A. COHEN
OZNAKI Project
La Trobe University
Bundoora 3083
Australia
Here is a version of Conway’s classic (i.e. 1969) game of
LIFE that has fairly advanced interactive facilities — one can
play God with aplomb - yet the program is less than 200 deci¬
mal bytes long, and when running uses only a few bytes for a
stack and the IK of memory in a Polymorphic Systems VDM.
(I eliminated the need for a IK next generation store by
“marking” the screen itself — indicating which live cells will die
in the next generation, and which dead cells will become alive
— without interfering with the neighbour count algorithm.)
The key idea in running the LIFE is that there is a little
screen creature — a NAKI — which can be commanded to move
about seeding or unseeding the screen. A more sophisticated
NAKI might drag a picture (e.g. a rocket ship) about the
screen, but that’s not called for here.
When this game is started the player is presented with a
clear TV screen. On pressing the E key, a NAKI appears on the
upper-left hand corner of die screen. The NAKI can be driven
about (and off) the screen using the commands:
N NORTH!
S SOUTH!
E EAST!
W WEST!
The NAKI will populate (“seed”) the screen cell it current¬
ly occupies in obedience to the commands
L LIFE Deposit an asterisk
K KILL Blank cell
Just what’s underneath the NAKI is not visible until the
NAKI moves on, or LIFE is started. The whole screen can be
cleared with the C command. When you are satisfied with the
way you have populated the world, you may grant it LIFE —
an autonomous existence determined by savage laws — by key¬
ing in the command G.
G GO
If you want to “single -step” — instead of G use the com¬
mand H:
H GO ONE GENERATION THEN HALT
The pattern is steady for about two seconds, then the cells
are marked for change. A dead cell in which life is to appear
in the next generation is marked by a solid blob. While a living
cell that is going to die is marked with a three-pronged graphic
character. (The display of the marked generation could be
eliminated by removing the corresponding CALL DELAY
in the program.) About 2 seconds later, the next genera¬
tion appears. Here is what happens to a set of traffic lights.
■
1
iii
i
<
■
Even though the Birth-Death agony sequence was started
on the G command, the display will halt on the next genera¬
tion by making ANY keystroke; once the display halts, this
keystroke is obeyed if it is a valid NAKI or LIFE command.
Elsewise, once the display has halted, the NAKI is sitting just
off the screen, and may be brought back onto the screen to
reseed or kill at your whim.
For those who haven’t met LIFE before, the following
details may be useful. Each of the 1024 cells (character posi¬
tions) on the screen has 8 neighbours. Cells with 2 live neigh¬
bours are stable, whilst if a cell has exactly 3 live neighbours it
will hold life in the next generation. Elsewise the next genera¬
tion in that cell is dead. These are the usual rules for LIFE, as
per Marvin Gardner’s articles in the Scientific American in
October 1970, and February 1971. Gardner’s articles include
pictures of the evolution of several interesting LIFE “worlds”,
including gliders and glider guns, pulsars and pentadecathlons,
and a host of stable patterns. In this implementation the
screen is large enough to display a glider gun, but the gliders
ejected bunch up and destroy each other on the screen bound¬
ary. Conway’s LIFE is played on an infinite lattice. In this
LIFE, off screen neighbours are always dead, and there is a
crude wrap-around on the screen sides.
Note that this program will not corrupt any location in
memory other than the actual program storage space, less
than 10 bytes of stack, and the VDM of course.
The program can be adapted to use the Processor Technol¬
ogy VDM, at the price of a modest increase in length, which is
then needed to properly count off-screen neighbours as dead.
A non-interactive version of LIFE on the P.T. VDM, written
by Marvin Wizenread, was printed in DDJ November 1976.
Unfortunately, Wizenread’s program, if unaltered, will corrupt
any memory within 10K or the top of the VDM.
I wrote this version of LIFE to provide a demonstration
piece that proves that pretty interesting things could be done
in tomorrow’s schools using 2 chip microcomputers. The 2
chips of this mythical computer would be a CPU with IK
RAM and IK PROM like the Intel MCS-80, and a video chip.
Number 24
l
Page 10
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
157
OZNAKI PROJECT CROSS ASSEMBLER OUTPUT
INTERACTIVE LIKE ON P0LY80
LIFE P8« 18-AUG-77 13133
SYMBOL TABLE
A
7
ALIVEC
AA
8
0
BLANK
3003
C
1
Cl
306C
CLEAR
3000
D
2
DEADC
7F
delay
30AS
deloop
30A8
DHARK
308D
EAST
309B
H
4
KBUPF
C0C
KILL
309F
LIFE
304 A
LIVE
30A2
LIVEMA
80
LMARK
3092
M
8
NARK
3088
NO
304 A
NORTH
3097
ONECCN
30B1
RE AD In
3013
READY
300C
SOUTH
3099
VDH
F800
VDNU
F8
NEST
309D
NHB
C20
s m re o>
SflN<KU s SKU
u cm kJ ea lj
U. 3* "1 ® JO
t- <n to e>
- r\ m o < o u. <s —
3 S3 X> CO CO ® CC » Oi
raa 333333
m m io m o n
CM ^ «f» <0
o» o» Ol »
a a a a
nmno
moo < b u o ui u. —• cm ■>
» » » o» o> o* » aa<<4
aaaasaa 3 a a ia a
m n m m m m m nimnnc
IO«KOOi<!DUU.B'i«nOKC 3
< < < <<<4<4IHI011CQ])00
aaaaaaasaaaaaaaa
nimnnmn'iini'iiniiinnmnin
M 1C Q
< « bJ
ui u n
kk a
a or
o u
<o t
z o s
►4 X ® 4
o s u. s <
3 *4
M I U
♦ 30
X X <
c ou
> > o
uuunu
or ar ®
o o o or
0 00410
< _j < x »-
4 X
o o
X X
*- ui o
a*-z
X Cl
Z ■< W
(TOO
< *- »-
z co co
uuu
-or a-
X o
♦ owes
CO X X Z UJ
407WMQ
UJ Z *1 X X o
3c M« Oc
1 O UJ 4 JC UJ 1C i
CO * ill X *
arxrxToroxirxxr
x x
< «,
9K0X4
< ►- U -I 3
j< x > jI i a
o ui uj - i-i *-« »o—o
r7aox<<jic« > ul
>- z u.
■* < u.
3 0 3
uun ■
-IX ■ 3
*-<ux r
►4 uj o o o
LJ u
>• o
>-«<»-t*-4*-»>4Q.f
3UiX»>OX i
< o _i x r o o -
m a
L Z O
JT 1
a o o x a >
1 4 Cl C O .
4 O <«"•<►■
3 OO O O X O X O X 13 »-« 1-4 IM » « j B X > 4 UI O > M NO _
-'CiUCUOUC.' <.'U/’G.'N< oUOaaiLClL —■ <
I04Q4Q404Ha4UUI <30 •40X000X03—0
OKu-ffiosnu.
U.U.MVBO jJU.
amxu.su® ® s
au.<pM®foio
<M «4 -4
-susnninsNamauaosBSKs-
Nonnion^inininMOMnMinMOMin'j
JUNLOUlCUOU'xUNUSU-UKl
.. — • — • — L JU.5ll.4U su mu-
l3iU.3U.Ju
muressores
niMEnn\u.n
CM U. UI O
snciKOPoQ am
33303333 — —
333 3 3 333 33
oimnomonn com
Oi4OUHO0OBO3ftlinK4OU.4»iOBi4 4lllOOU.
rt-^rtNiuNMucunininooinoMM^ < < -mmmi ^
333 3 33333333 3 33333333333 3 33
nnn , n>Tnpnnninin'ininni l ino»inininnrvnnn
us — NinvinoNOo < iuu.sm4 ® ci
'IB.TClClCl.'lClO.TinOOBOCOOOC
33333333333 3 3333 3 333
nnnmnnninn'iinnninnininininn
O O w U. <M IT *0 O X) U
OOdCNSNN re K
33333333 3 3
oominooinin o in
Number 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
158
A IK DEBUGGER for the Z-80
BY LES HANCOCK
305 Lexington Ave 7-C
New York, NY 10016
The IK Debugger is really a 0. 951 17188K debugger. This
version is assembled to start at 074061 octal. That puts it at
the top of 16K, up out of the way of most programs. The code
must be assembled to end at a page boundary (***/377 octal,
**FF hex). The debugger is meant to run on a Digital Group
Z-80 system with ZE audio ROM, TVC-64 video interface and
TVC-64 monitor.
This debugger provides the following features:
• Display the contents of every Z-80 register as it was
at the moment the debugger was invoked.
• Display the current contents of any memory location,
using extended addressing, register indirect addressing
or indexed addressing.
• Change the contents of any register buffer.
• Change the contents of any memory location in RAM,
using the three addressing modes mentioned above.
• Load the Z-80 registers from register buffers and
jump to any address, with or without enabling inter¬
rupts and with or without setting a breakpoint.
• Load the Z-80 registers from register buffers and
jump to the most recently set breakpoint, with or
without enabling interrupts and with or without
setting a new breakpoint.
• Jump to Op Sys program/dump, with automatic
return to the debugger.
• Swap contents of register buffers with Z-80 alternate
registers.
• Display any 8-bit value in binary notation.
• Give the two’s complement of any 8-bit value.
• Add or subtract two 16-bit values in split octal or
hex.
• Display or set mode (hex or octal).
• Clear TV screen.
This is a simple debugger, and using it should be fairly
straight-forward even for new programmers. Get an assemb¬
ly listing of the code to be debugged so you’ll know the
address of every instruction. Load TVC-64 Op Sys, debugger
and target program. Create a new Op Sys option to jump to
the debugger, then use execute and breakpoint commands to
run your program piecemeal. Whenever it reaches a breakpoint
the program will return to the debugger; try the various dis¬
play commands to see exactly what’s been happening in the
CPU and in memory. You may want to load new values, then
jump back into the target code. You always have access to the
system program/dump (via the ? command) to do extensive
reprogramming or to display large blocks of contiguous
memory.
When you jump to the debugger it resets the stack point,
disables interrupts, and inserts the debugger’s start address at
001025—001026. (This last step vectors RST 070 back to the
debugger.) Then it loads a set of buffers with the contents of
the Z-80 registers, removes any breakpoints that may have
been set, and waits for input. If you want to re-enable inter¬
rupts, use the XI and ZI commands; if you want to keep the
stack pointer at its original value, use SP = nn. (This paragraph
may not make sense first time around. Reread it after looking
over the list of commands.)
The input prompt is a six-space indentation, a la APL. You
can type in up to 20 characters per line, including blanks and
the carriage return. (Blanks are ignored when a command is
decoded.) Use the RUB key to erase typos. If necessary, rub
right back to the beginning of the line — you can’t go past it.
The error message is a question mark.
A few words of caution are in order at this point. When you
look at the load commands you’ll see that there’s a big differ¬
ence between changing the contents of register buffers and the
contents of memory. If you give the command A = 015, what
you’re doing is loading 015 into a buffer, which will in turn be
loaded into Z-80 register A when you give an execute
command. But if you say (001001) = 015, you really and
immediately put the value 015 into memory location 001001.
Think twice.
When you set a breakpoint at a certain address, the debug¬
ger copies the byte it finds there into a buffer and replaces it
with 377, which is the RST 070 instruction. This restart is
vectored back to the debugger, which will take out the 377
and restore the original byte. Be sure that the breakpoint
address you give points to the first byte of an executable
instruction in the target program, or that program will surely
bomb. If it does, for this or any other reason, then control
won’t return to the debugger, and you must remember that
the instruction at the breakpoint address is RST 070 and not
the original article.
The Z (or ZI) command allows you to jump to the most
recently set breakpoint, which means the last breakpoint set
since you loaded the debugger. Be aware of that, and of the
fact that if you jump to a breakpoint and set a new breakpoint
at the same address, you’ll bounce right back.
The debugger prefers to work in octal. You can switch it to
hex with the M command, but it will reset itself to octal mode
when you come back from a breakpoint. If you enter a hex
value in octal mode, you’ll get an error message; but an octal
number may be accepted when you’re working in hex, with
incorrect results.
1K Debugger Summary
Conventions :
Punctuation marks, math symbols and capital letters must
be typed at the keyboard just as they appear here.
Lower-case n stands for any 8-bit value, nn for any 16-bit
value, d for any 8-bit two’s-complement displacement. When
the debugger is in octal mode these values will be given in octal
notation, when in hex in hex.
Brackets indicate a choice. For example, {± ) means that
you may enter either a plus sign or a minus sign. (But you
must use one or the other.)
Square brackets enclose optional entries. For instance,
H [L] means that you may enter either HL or just H.
Input :
The debugger prompts for input by indenting six spaces.
The rubout character (377) backspaces the cursor and erases
the previous entry. You can type in up to 20 characters per
line, including blanks and carriage return. When a command is
decoded the blanks are ignored. The 21st character creates an
error condition, and all input is scrubbed.
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
159
COMMANDS
Register indirect addressing
1. SCREEN CLEAR COMMAND
2. MODE COMMANDS
2.1 Display Mode
2.2 Set Mode
Clears TV screen.
Returns H if mode is hex, 0 if
mode is octal
0 sets octal mode, H sets hex
HL Returns the value currently
BC stored at memory address speci-
( DE ) _ n fiedby the contents of the 16-bit
SP register buffer
.C Indexed addressing
IX 1 Returns the value stored at
( IY | + memory address specified by
contents of the 16-bit buffer,
offset by the two’s -complement
displacement d. The plus sign
may be any nonblank character.
5. LOAD COMMANDS
3. ARITHMETIC COMMANDS
3.1 Binary Display
3.2 Two’s Complements
Displays n in binary notation
Returns the two’s complement
(NEG)
3.3 Addition and Subtraction
5.1 Load 8-bit Register
Loads the value n into the speci¬
fied register buffer.
5.2 Load 16-bit Registers
Loads the value nn into the
specified 16-bit register
buffer
± nn, nn
Using reverse Polish notation,
finds the sum of two 16-bit
values or the difference between
them. The comma may be any
non-blank character. Note: octal
arithmetic is done in split octal,
where 000377 + 000001 =
001000
4. DISPLAY COMMANDS
4.1 8-bit Register Display
Returns the value currently
stored in the specified register
buffer. Command 3.1 may be
used to interpret F
4.2 16-bit Register Display
H [L
B C]
D [E
S[P]
IX
IY
4.3 Memory Display
Returns the value currently
stored in the specified 16-bit
register buffer. Note that L, C
and E can’t be displayed as
single registers
4.3.A Extended addressing
Returns the value currently
stored at memory address nn
5.3 Load Memory
5.3.A Extended addressing
(nn) = n Loads the 8-bit value into
memory at the address
specified by the 16-bit value
5.3 .B Register indirect addressing
Loads the 8-bit value into
memory at the address
specified by the contents of the
of the 16-bit register buffer
Indexed addressing
+ d ) = n
Loads the 8 -bit value into mem-
moiy at the address specified by
contents of the 16-bit buffer,
offset by the two’s-complement
displacement d. The plus sign
may be any nonblank character.
6. EXECUTE COMMANDS
6.1 Execute from a Given Address
X [ I ] nn Loads the Z-80 registers from
the debugger’s register buffers
and jumps to address nn. If the
command is XI, interrupts are
enabled
Number 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
6.2 Execute from Last Breakpoint
Z [ I ] Loads the Z- 80 registers from
the debugger’s register buffers
and jumps to the most recently
set breakpoint. If no breakpoint
has been set, control passes back
to the debugger. If the command
is ZI, interrupts are enabled
7. BREAKPOINT COMMANDS
7.1 Set Breakpoint and Execute from a Given Address
X [ I ] nn, nn Loads the Z-80 registers from
the debugger’s register buffers
and jumps to address specified
by the first 16-bit value, with
breakpoint set at address speci¬
fied by the second 16-bit value.
If the command is XI, interrupts
are enabled
7.2 Set New Breakpoint and Execute from Last Breakpoint
Z [I] , nn Loads the Z-80 registers from
the debugger’s register buffers
and jumps to the most recently
set breakpoint, with a new
breakpoint set at address speci¬
fied by the 16-bit value. If the
commands are ZI. Interrupts are
enabled
7.3 Display Last Breakpoint
E Displays the most recently set
breakpoint, the one to which Z
or ZI will jump
8. DUMP COMMAND
? Loads the Z-80 registers from
the debugger’s register buffers
and jumps to address 003000.
All the usual monitor program/
dump functions are available,
but the command R will return
control to the debugger and not
to the monitor
9. REGISTER SWAP COMMAND
& Loads the Z-80 registers from
the debugger’s register buffers,
then swaps them with alternate
registers and returns control to
the debugger
FOOTNOTES TO THE CODE
1: Line 180. The TVC-64 monitor vectors RST 070 to the
address contained at 001025 — 001026. We want that to
be the debugger’s start address—in this recension, 074061.
2: Line 270. The byte at 001247 is a mode code. If it’s
ASCII ‘H’, the current mode is hex; if not, octal.
Subroutines NUMOUT and FINDMO, and the mode-set-or-
display routine SHOWMO, make use of this Digital Group
convention.
3: Line 370. When the debugger is initialized, FLAG and
FLAG + 1 contain a jump instruction as shown. As soon as
you set a breakpoint, that instruction is replaced by a NOP
and a load-HL-immediate. ZBP and ZBP + 1 always
contain the address of the last breakpoint set. (It’s
initialized to the program’s start address.) BPBUF contains
the byte located at (ZBP). When you come back from a
breakpoint HL is loaded with the breakpoint address, A
is loaded with the byte to be replaced in the target code,
the byte is put back where it belongs, and the instructions
at FLAG and FLAG +1 are reset to JR NN0.
4: Lines 430, 1070. Users of TVC-64 return from the system
dump by jumping to the address at 003376 — 003377.
This is normally 005000, the monitor’s entry point. The
debug command *?’ will substitute the address NN0. So you
can go straight into the excellent system dump, use all
its features, then return to the debugger without disturbing
the contents of the register buffers.
5: Line 3290. This subroutine was cribbed from Dave Bryant’s
PHIMON listing, published by the Digital Group. (PHIMON
is DGI’s Phi-Deck monitor.) I changed the code to work
with TVC-64, but the hardware is a mystery to me, so
I’ve left out comments. (This is another way of saying that
I don’t know how the subroutine works.)
The TVC-64 support routines used by the IK Debugger are
as follows:
TV—prints ASCII byte in the accumulator on TV screen
SPACE—prints one blank space
ERASE—clears TV
KEYBD—gets a byte from the keyboard
NUMOUT—prints the value in register E as two hex digits
or three octal digits, depending on what’s in 001247. (See
note #2.)
Page 14
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
161
Q. -u X <D X
•X Dn Qj -u 0)
•Q X) .q a .q
a i
■r-,Tj q fc<
TJ -C X Q)
C O O Q, 3 Cn
-x -x >tj *j 0<
. CM3
S O i 0) X 45
Ofi *J 0)
fa v .. tj -t>
a: a, q> fa q _
6 c 2 nj 'x
0) a x fa o <x
X T> 44 fa U)
O 3 X X «*
X**O«0fl)X-
tn X X q -u u
QJ X <fl x *J
« «M O 3 'X (ft -X
in X Cjuj tn
<D 3 I <U 0) O lo
X) m x x -u n
q J< Q) -u fa i
•x C x O H I
a t C u X;
■X -X X
XJ O ITS O fX
S k “ V
w x «i to
0) QJ QJ tfl QJ tfl
Jx q fa fa lx H :
3
Z A
X CD u
Z M Z UL
o ‘Ha:
UA JUI.
XL
I X- UJ A
10.0.0 Z N
• X Q£ X- A ~
oxL' - - :
I 3 Z UJ N 3
Z X l
t *. « Z W ~ © N <£ ~ ' 10 3 3 3
30 u o <r o o. z n in uj a. u. in a >o a n a o> o.
o cd cn uj z o x z ro z x x <t z « z u. zo: z *x
IZIO 'X'OC' * 3 *■ O ' * 3 »■ CM ' - - A ' - - Q - » ■> Q % * f- %X'
U.X«NJZU.NJZOCNJZHNXUJXX - 3
IZCQUJ' N ' N' Z X ~ X ~ o - ZX'-'O « 0) ' Z Ik' Z X U. ' Z X U. - ZHOH ' N>
> ^^ IL ^ ll '^ &i ^ <k - £aa ^ LLa:Qfl ^ Q ^ aa ‘ & - a - a -^ lk -KQQflQ&-&-O.QQLl(XLLO:QI>:La:QO!LQ:aLLL3^0LLLLQ
IUUTUTUlUT(JTJJUTUTJJUJUJTUTCJTUlJJJJTUTJJTIilliJTinjTUTJ”)(JTJTUTLULUTUTJ
O O O O O O «X
o x cm w v in in
n n n n n n n
o o o o o o o
S59?2?9°5!22.9 0 ?2 0000000000000000000 oooooooooooooooooooooooooooooooooo
XXNNNNSrnmSi5S!Smmm^^J!C^^?^ OHNr),rin ' OPsCDI> ' OHNM ^ in ' flNII,l> ' OHP,Mtln,ON ® (>,OHMn ^ ln, <I N ®'>'0^
©©0©00000000©0©00000©00000T-t*-»»H»H*H*-«*-»»HiX»H»-«»x»x»x»x«H*M»x»x*x»H»x»x»H»H»x»x»H,x. I H,x»H»H»x,H,x,-i,-iT*,HT-i»x
o >o rx n
-< <r o »x
o own
O'Oinru
CMOhOI
OOMMt
Hioinot
-O-O-OM
PM CM CM CM C
IX IX IN IX f
o o o o <
on <r
ON N
o o o
in <r >o <
'X t (N M
ro o h in x i
ino in in >o pm '
in ro ix h x x r
O O I*) M 10 IO I
n^r'O'O'O'or-jiONc
NNNNNNOOO'
PMCMCMCMPMPirororor
<r'»r<r<r<r<r«r<j-<r<
NNNNNNNNNf
ooooooooot
NNN <r>0N'O <T CM CM W -0 m
NNN NNNN NOONNN
ooo oooo oooooo
<r<rincM'0NCM* > <r«-'0'0ino*- -o 'OCMioonownn
(MMxinxxMHinonooiMin o on cm n >oinroNH
MNnHrmnoHMHNMOH *x HomnncMioNo
'OPM'OPM'OCM'OOCMCMinrO'OOCMVininin'OrO'OCM'OCM'OO
NHNHNHN<nn<rHON<nnnHt«ixooNHNHNT
MnNnnMMOooMMMOOHnHnoMnnnMMO
fMNHVMjxninoi'i'OHninoH^inoNinNCMtNx
HHHM(MiMnnn'r<r<rninin'0'0'C'ONNNNooo«
M'O^n'O iniO'0'0
ONNON NNNN
OOOOO OOOO
o^O'O'O'omo^-'O
lOONNtt ninot
lonxncMCMooncM
fMNH^-oxninow'OxninoH^inocMinNCMtNx
HHHNCMiMnniottTininin'O'O'O'ONNNNoooH
rororororororororororororororotorororororororoooo©
o-;*<r<r<r<r4r<r<r4r<r<r<r<r<r<r<r<j-«-<r4r**-inininin
NNNNNNNNNNNNNNNNNNNNNNNNNNN
ooooooooooooooooooooooooooo
otp-O'O'OinoTM) OHinoO'OnNNNn«o>OHM)intrxOHHCMn
ooNN^tninot NOo-oinooinncMOOCMxMJtcMtntnt'O
OMhWCMCMOOWCM OnONOnONOnOMOMOMHlDnOMOIM
H(MHCMro-o!MH(MnHOM>ooHO'OoxO'OOHO'Ooinnin' 00 'OOH
tt^^oNOttonHONttnNttnNttWNtNHNNinNinv
oooorororooororoororooooroooorooooroororororoorooo
ID'Dx^NCMtNCMinOxCMinNxt'OOCMinNxrO-OOCMt'OxmnNxn
HHCMrMtMnnnwinmninin'O'O'ONNNNoooHHXHCMCNCMCMnn
0000000000000 000000000 <x*H«x^«x«x«x«x*x<x*x«x«x
ininininininininininintf}ininininininrcininininininin«inininbnninintt
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
ooooooooooooooooooooooooooooooooooo
QJ JD >X UJ H
X X q <g ^x
o u m
to C X JI QJ
0 X) 4J -U
. 3- >
X X X C C
to to to to *X
QJ -U -U -U
to q q q to
(Q M ■», 4J
, X X X X QJ
fa fa fa fa e>
'O CM O “O O
■ <r n n o in
ro ro ro »x cm
■ o o o n h
OOOOO
■OOOOO
3 3 3 3 3 U.
•aocoo 3
lu u uj lu u a
0) X ~
- - in
~ ~ cm
U. X- U. K O
3 cn 3 CD x
1 U. U. U. U. U.
• 3 3 3 3 3
* h a o: a aaa
> - XH » £t J |l N A
<X~<T'-'X'-'~~
U. lOIO''
3 O •■ O M)
a <x «r ~ m n
Q. ‘HCDOIOLI
A^OQIOIOW
o ~ 3 * 3 - o «
Z X- 'I Jli. JOL
zcn<r^x — x^uj
A X- <X
A Z Z X - A
WOHH Z ~ GO
O ZCM - >- m * 3 ro
uj o cn
« Z CJ N -
► H QJ N N
XXX
cn a. cd o. cn
QQt-tAAQ30Q30Q3QQi
JjajJJLa.Ju.ij_lu_13.
uj u 3 a <r
cn a o a o
<t <z r >- 3 PM
CC Z> (L 3 UJ X- X-
UJXCDZZ1MMHD CO
• -rxPMrOO-IO'ONAOOOOOOOOOOOOOOO
iwroroioioroioiO'ryD'ONCDD'OxcMioirin'ONCO
i ^ ’X »x th tX tx tx ^x »h »h pM C^‘4 CM CM CM P*J CM CM
• OOOOOOOOOOOOOOOOOOOOOOO
‘W » JIIIHNI » * X UJ ^ in - a x _>
A JAIZIMZvQOlia _JQIOZ_JN_JAAr-CJ'-'l-
-J -J -I 3 3 3
3 3 A 3 UUU33 3
AtXAACCLCCAAAA <1 C£ L Oi Z CC Z Z « « ^ A <1
3(J33UU"133Q3 U3U3>-h-Q > -)»-iUU33U
OOOOOOOO^PMIOOOOOOOOOO^CMrOO-OOOOOOOOOOOOOOOOOOOOOOOO
?2i2! n,, ' in ' 0 ' 0 ' < >' ON ® | > , O r, ^ ,, ’tiniflioinin'ONfflo>OHPMio^in'ONAi>'OHMio , ryi'ONCDO>
CMiorororororoiororoiorororo^ro-^-^'^-o’^'O'O'^-o-^’^ro'ioioioiombTUTininin'n'O'O'O'O * * * - *
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO©
'O 'O 'O -n
OOOOO
*x -o *f x
ON N N O
ro o ooo
•o <o >0 >0
OOOOO
O-O-O-O-O-
N N N N N
OOOOO
ro ^ o x in in o m nnnion , o n ro ro
'O'O N'OPmo* in^- m x ^ pm >0 10 o in o cm
»x o pm o o ro pm ro cm ro pm th pm ^ ro cm^^
in»xiopM'xcMin»xCMin^xCMin'OCMincMincM*-*CMinin
in'O'Oo-o-o-ro^-o-No-o-'ON'Oin'Oin'Oo-o-iniio
rooroooororooroiooroooroorooroororo
HHHXHxxHxinOxtrNPM^inOtMIO'ONH^MJxrO'ONPM'ONPM
-O'O'O'D'O'O'O-D'O-ONNNNOOOxxHHHNPMPMIOIOIOrOl'triilin
OOOOOOOOOOOOOO HXHHHHXHHHHHHHXHrlHH
n t vinroo
N »x N O O ©
O OOOOO
o- tr OCMO'O'O
hnio ioinoN»
o o ro o ^ o ro ro
OxCMNxCMxCMin
lO'ON'OtM’ttrx
ooo«xooooro
•ON^-NinwcM >o
O O (MN H H H *■
oroororocMO o
N CM N in ro *x PM "O PM
oo-Nth 5r ro n h is
ro o ro o ro roroo ro
u m m m m i\ u u u h h h h h n rj n n id n “ " id uj
OOOOOOOOOOOOOvHvXT-tTXiXiHiXiXiHiHiXiXiXfXfX^^^T-t
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
oxiMNxCMxcMin 'Oin>OHin'OON'OOMiTO'00vo<i-trininoMn
N'GN'O^^^ Vx OxOtHNt'ONOO^MNtnilininOHxn-OH
ooo^ooooro onoonno«xoCM^nonooooonnorHro
pMPMV'OxcMinon'OxHHHHn'OOM'OoiMMin'ONCMV'OOxrovinomn'O
inininin-o>o>oNNNoooooooHHHCMCMN(MtM(MroroMv<rM i «r^inininin
’X »x »x »x »x »x »x t-< CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM PM PI PM PM PM PM P J PM PM CM PM PM CM
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Number 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
« to -f TJ •
« « m c tj
l) M m q
l-i w. o -i
Ta tj o O
T3 T3 CQ
<0 <0 M &>
_ O O QJ
■O U *J v.
«j id x q
• * TD 0) O Qj '
«J C « -u C .
I T3 QJ to -H
c -u o 0 ) a -u
-h x i -u e 3
q 4J *J '
i a-" 1
U 0) Qj T3
<l) M o c m
■U M S: m O O
to 0) *~i *• *-f
'2 ^ O O D, o, O
t» <*h -*j to o "o -u
Qj3qu-~ioqq.
^ ■ft •n m ‘B N HJ ••-<
4J 3 o q
y x 6 q rv. o u
tn <a -c u -U o
q to -u \ *j •
O X O O X U
■u 0) QJ &> QJ
q X O q u -q Qj
*H O ■*-* •-* *• Is
q <j 4 j wiJO-
O' -~i QJ to QJ Qj 4J
H Q 15 H X 15 to '
00 3 3
- Z 2
Z Cl <X X <
In 3 >03 rx 3 003
Hfi v* iZl ■>-! iXl H IXl
2 I ic z n ce zqk z cn u.
- - Q ' - Q % * Q v .. .. Q
X. ~ ~
3 _J _J
Z X X
-X V w
X
O CJ U
' * - Si. -‘O' - -Q' 51-' X' 5-a: » X i £ oot « ® « « ® q 5 i Ji-hhiimxur!<ri3
XNJ2fiNJ2QNJ2WNJ2ldX ►>■ ►CCJXJUJUJ »j »CJJ fc O ‘ *• _J 3 - _J _J CJ Z Ci •. _j »■ UJ UJ UJ —< •- UJ ® u£ *■ *-3 •. <v
% 2 X *-* ' zx»-*' ZX>H' ZX H(5» M' NUJXXXOZUXOBXfDNU U^KflUZICQH Z UXC6OOOWN2v0.«LJ2«iUI
i-i
-i _i_ix x 1111 I
3r<r-'»- uj
UJ _l _l U3-H03Q J-
o: i x x z ~ ll » 3
►i w vhh(-nwxui''«i'0 cj
a -_i - uj uj uj h - uj co it •- »-3 - ct. uj
-J _j _j u cn a. cj u: cj d tn n
QCIi.CCQIl'Q.CI'fiiZ^Q.ltCQ.KQCaQ'Q^CaZQDOaLIZliJQOAKQQJOK
3U3_J303_l3U03U33-J3-IUU_J«_| < l.tL_/U3Z-ix“T3«5°3
OC CJ
UJ Q Z
t- _| i-t
cn
-J -I -I
Q <t <1 <1
_l U U U
HACOLQi
U 3 (J _J 3 _l .
> O O O O <
■OOO'OhC
> O O »H sH .
I CM CM CN CM C
h N I*) O O
O O O- O T-.
m m m mj mj
CM CM CM CM CN
o o o o
Niotn
■O'O'O'O
CN CN CN CN
© o o o o o
■OMDO>OH
m> >o >o m> rx rx
CN CN CN CN CN CN
o o o o h cm n
cn ro m- in m in in
rx x. rx rx rx rx ix
CN CN CM CN CN CN CN
r HvoinoNCNinn'O^in'OinninH
* M-CN^OfS^OONOOOrsrNCNOO
> HHiOONHnONHlQOMOMOM
JNOIO'OOHO'OOHO'OOHOMJOrt
-Hr<)HNwnMr<rnNVfnNv<r
iHOMnooowooonooonoo
lOHrxONWNHM'OOCJtNHMn
sixrxrxrxoooo^.n^cNCNCNCNnron
innnnoooooooooooooo
TinUTU’JUT'O'O'O'O'O'O'O'O'O'O'O'O'O'O
•vrxrsrxrxrxrxrxrxrxrxrxrxrxrxrxrxrxrx
>000000000000000000
r* m> m> rx rx
rx rx rx rx rx
o 0000
WO-OHN tow
•oNMononinoincMH
OhMOMOCMCMOCNhO
oifl'OO'OOOHOHnio.
MnNinMnn^mcHH.
onnoroooooown-
oMinrx^nmrxcNM-rxcMi
<rv^^wininin'0'0'0M
oooooooooooo*
'OMJOM3M)M)M>M3M)M)M)M3-
rxrxrxrxfxfxrxrxrxrvrsrsi
oooooooooooo<
O O O M-
O O o
OCNOH
oo^OHinio<on'Oio^’<>'OOinNMnoNHioHO
intotMVHHHtootONMnHininnHn^on
OOOOOMM*iO^r0MOnOM»HCMf*)O^OnMO
MinMNtNCNin'ONOHnt'OOtNM’r-OOHCNWt'O'fl'
ninin'O'O'OVVVVOOOOOHHHHHCNCNCNNCNNNC
'O'O'O'O'O'O'O'O'O'O'O'C'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'
^ l ^!^!^^ ,srs ' r ' rsfs,s ‘ ,srsrsr ^ rsrsrs ' rsrxrvrs ' rs 'f N 'f^rxf s r
OOOOOOOOOOOOOOOOOOOOOOOOOOOC
<r <r m- in rx <r r-i -o in in
(N CN (N h o H o OrxCM
HHHNOO CM t-i © m
> >o in in in
r o ^
> h M M M
3 M> M3 M3 >0
v rx rx rx rx
>0000
*o o in cm
rx in ^ o
moiqo
•O'O'O'O
rx rx rx rx
0000
m n cn rx in mj r
5 O H I*) H O <
> no h n o r
h cn in >o rx cm *
■) in m in in >o >
^ H H H »H 1
O'O'O'OO'O'
s rx rx rx rx rx r
> o o o o o <
m- tx rx rx
m> mj m> mi
H H H H
>0 >0 M3 >0
rx rx rx rx
0000
I ~i --i 6l l, U -H
1 <tj xj \ o i q
*j 1 •* O u -1 •
1 cj aj u u h]
1 0 Qj *j qj *j
O x, U c •
. *J *J X) ' HJ -H •
iQjqstoOQX-
; 13 ■-! J5 X i J Q, I
q xj x,
•u -h 1 x,
Qj u vo 3
U. U. U. U. U. XU.
o r <Z CC ~ b- 3 3 03 -H 3 CM3 1-3
X 3 - K CC J3fi ® Ch *-.« 1 X 1 ^ CD < 1 *
W2 ^ Cl UJIOh XO>-Q ZXQ ZQQ ZNQ XCO
•- ' ► x j tin - '-r <o - z - z ' - »Z' - -z> - -Z' - -
UJ I NUJIAhN - 3 - 0C_|i-<_|i-ilrx|_JHHCSM_Ji-iflCilxl_Ji-iU3NJ
O ' ZZ~a.CNZUJZ®UJXU.XU.' Z X U. ' ZXU.' ZXU.' ZX
-J -J -J
-l-I -I
<xa.C£€QCuCLGc:Q^QQ:Qa:i=iixcLC£QQ:Q.iXQa:a.iXQGe:a.Q.Q
CJU->CJ_J-)CJ-3_IU_|-3_J-)_/-3CJ-)_J-)CJ-).J-3CJ-3_J->U-)_l
o x •• r~ _j 3 a
x z ~ a. x o 03
CNi-incnocN x_j h r rj cm in
- uj »-i - Cl - j UJ I j Cl a: - _] - 3 _j U. - ix:
AOriNJAXZvXJiLAXUJZXJaUl
_l N -J N _J N
_j z (j-j u z a _i u z
a^a.onaz^MUJ'Do.azaciinMA
JUUTflJHUJBQTjHJUaajT
cn ro uj cl
- ' M3 Z X >-
cl - ^ ^ lc oc
cn « 1 — a _j n. o
cn jzq
3 a <z o cl cc
u. J <J u Cl (J ~1
■C. Z » * * li. _J UJ -J * -M- -M- UJ UJ * * * CC 3
-*CNmp00000000000©000000000000000000»-iCNro00000000000000000000«-«CNm000000^CNm00©0000
•H^HCMn^in'ONfflo-OHCMrM'in'ONCDO'OHNnvin'ONcoo-OHNCMNCJMirin'ONajO'OHnnvin'OMDO'OHrKJCNfjMvin'ONOoajcDmo'OHWMvin
^M-^vM-^M-^^^M-inininininininininin'O'OM)'OM3-n'O'O'O'orxrxrxrxrxrxrxrvrxrxrvrxrxa3ajo3C000CD03a3C0a3(>'O'C>'O'O'C>'i>'O'C>'C>'O'(>'C>'O'(>'' ,, “' ,v ^^^^' i '
O' o o 0 0 o o
*-> CM C4 CI CN (N CN
mj rx >0
rx ix rx
o 00
in ix —* m m •oininoo^n
cn n o - o -< m OMiininmvr
HNOO NCM h hOhCNOCNO
in •oomMQ'O o-cin-oono no
h-oon t mhom vn vn
ronoro^nno-iMoooooo
•fl'O'O'OHninoHt'OOHfoonino
MnnrovM-M-inininin'O'O'O'Oixrxrxo
ItHiHCM
mmminin^JininininiiTinininininininin
NNNXNNXNNNXNXXNNNNX
OOOOOOOOOOOOOOOOOOO
oino(N»in<iHninnoi
^orxmooNCNOorx~«(
noNonoNonoNoi
'OO^O'OO^O'OO^O'
r\^r^rnfX5j-«rnrx«r5j-nr
mooonooonooor
CNM , '0*HroinrxcN*-'Ooroi
oooHHHHfjrgrjnnr
CNCMCNCNCNCNCNCNCNCMCNCMC
ininininuTUTinininininini
rxrxrxrxrxrvrxr^rxr^rxrxr
oooooooooooo<
cq m- in rx rx cm
O CN ^ 1-* M3 O
OhNOMO
>inM300MjroinixnoroM3MM3inrooM30
> ix in cn o <r ^ 0 yj cn o o <r ro ij-j cm o ro
>ronoooom^HOOMoo-irooooo
h X C-J X x H
M3 rx rx rx o o
o cn ro o ro CN
h mi in m) in n
M) N h O h O
0 o n o m ro
in n *r n h ih h
vr o n x <r in cn
n o h n n cn o
in M) in o in M) o
N O H N X X n
nononno
iiTXC'nninininxN'r'OorjM'OxofjnxortirinxrtMnnnMiownoinrQnninxNvMJO
nnvrvr»vr«MrinininM)M)MiM)M)XxxxooooOHHHHHHrK<(NnnnnnnnvMMrin
r-j cn C'l r-i cn cn cn cn cn cn cn cn cn cm cn cm cn cn cn cn r*> m to m t*j m i*> ro r*) ro ro ro to 10 r*j ro ro ro m ro r*j 10 ro r*j ro
in yj in in in in in ut ut in in y-> in ut in in in ut ut in in yT in yT yi yi in yT yT yT in ui in y-) y-j in in in in in yj in in in in
rxr-''rxrv(xrxrxrxrNf\rx(xrxrxixrvrxrxrxr'*rxrxrxfxrxrxrxrxrxixrxixrxfxixrxrxixrxrxixrxrxrxix
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
163
0 O <N
U U ~f -U -s
■u -U O 0) U,
» in o « bi
HJ 4J
C C -U V pH 0
0 0 <u - **s c :
t, tt » o <u +->
a; -u is is 3
a w 5) o fl
0) Q) .£} N 4J N —
t> b> W)
m m ^ 0)
to to h a:
■C Q) U
*J is (\. «j qi
O X *1 U
<0 U Q> T3 Cn
*■ T3 ^ -u
8 8-8
TJ <0 ID *j 'H Hi b
is +j -c oi m c
'aisoxj.qao:*
c i» « *j o <3
O C -1 t) 8 *J c
*J O -C C Qj c -~l
to O u H C 'S J3
r o i
3 r x
Z Q UJ
*- -I 2 Z
LU<IUH-
O^UIlN
OCI-J
o - ui <r
ro o o :>
o <r k j n
n - Ui c o u
OUOODOUOA
I I
cn cn cl cl r-
33QQu.OAOUJ
Clu.JJUQ.JQ.CC
CNro©ooo©oo©o*-«cNro<
NNooo>OHNn^m-oo«o>or
roMroM^ww^<r^<r<r*
nonmonioromoMioionr
:«J <c« _j _j
» -J OCJQ -J -J CJ U CJ A Q J J u u 0. I- _J CJ CJ U CJ
!«CCfl:Q:2Q««JJJ2QQ<I<I2aQ > OliJ«JJJJ(
.UnQCQC^JUUQCQCQC^^JUCJC^UQ.QCUQCQ'^IC.
>0000»-*(NM^ , 0000000000000000000000OOOOOOO
JC'!ro^ininininin'*OPNOO<>*o*HCNro* , in''OrNa)ch©*4CNro^in , oiN©o*©«HCMro^
uninmninininininininin-O'O'O'O'O'O'O'O'O'ONNNNNNNNNMDajiDfflCQ
irororororororororororororororororororororororororororororororororororororo
Z <1 3 O *-•
«h-_JX CN Z rN O CL >- O
► u <x uj a in - o >o u .cl v ► v
ao^za a ri u o C'i lu >-h <x r-j
UJ u.
-J -J _j y- u.
j j j q o. h a a r— >-3 a
o<i<r«aoujQ.cc33UJ aa uao.
juuu«ro.ccuno(occ a ju
<t K
ct: 3
UJ l-O.
<1 A UJ Z
x r cd •-* r-
U 3 UJ
I Z * * * » CD
oooooooooooo^(Mn<roo©
in'ONOO-OHNIOVin'O'O'O-O'ONCDO'
OAAAOQ<IMMMMS^(HSQ-0>Q>0>I)>
rmemmoioioioioioioioioroioionio
^'OfN^-rs^'fN^'TH
wnoocvmHMM
OM^^ONMO
-OHinoNoon
m wnowonn
■ONMO'OO'ONh
NNHIDMONNH
rororooroorororo
<r o *• rs
cm rs inn
«-< CO fO ©
in in in in © r
HHOnin.
ro ro ro ro o <
o ©
© cm rs
ro *-< ro
CM cm n ©
rs o o >o
CM O © CM
ininininin > 0'0'0'0'0'0rNrsrN^nv(Noo©OT-4iH*H*HiH«HiHi-iCMCMCM
nnnnnnnnnnnrofmnnnooooooooooooooo
'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'orNfNiNrsrNrsrNrNrNrNrNfNrNrNrN
rsrNrNrNrxrNrNrNrvfNrsrsrNrsrNfNrNrNrNrNr^rNrNrNrNrsfNfNrsrNrNiN
000©©©©0©©©000©©©©©©©©©0©00©©000
rsrNM)rNioinrNfNrs>o^rsio»n'0»H«o^^inrNrNrNrNNininin©^^'0©'0'0^
^ l ^^-^^HOoosro-H^-.trorNo-H-H©©ooo^--<-.oo^NrNCMrjTH
ooMHioiooooioNHioioiiNionionooooHioioncMioiorooioioio
2SCi5!f2 on, ' ,n,0O,H(V,,no(NM ^'0 r>s ‘^M^inMjrNCMin©^cMninfN^n^-^
toMronn^'v^-^-^-inininin'0'0'0>0'0'OrNrsrNrNrNrNo©»-«^»H»H^H»-iCMCMCMCM
00000000000000000000000000*-i»-<*-s»h»h.h»-<*h»h»h»h.-s
rNrvisrNiNiNrs.i\rN|VviNiNrsvrNrNrsrNrNrNrNrs.iNfv.rvrsrvN.rNrNrNfNrNrNrNfNrNrNrN
rsrviNrNrv.fNrvfNrNNN.rNrvrNrvrsrNrviNr'.rNr'.fNrNrNiNr'.rNrNrsrNfNrNrNfNfNrNrs
0©©©©00©©©00©©©0©©0©©©©©©©©0©0©©©©©0©©
N N N N N
fN fN rs fN PS
© © o © o
c l§ “-il
01 3 c O. <« 4J J
•C -t-i
■U *J *. 'O +J -
i OX* H j) '
I «. 4J 0) O bn
: u c c *j -H t
<0 T3 >Si
j -c c
: -u »o ts
) -*J u $
i, <U Q) fn
; 0s 42 at
j 0) <+s *j
j -u 3 --s Q)
( S iJ
» u q> 5
tJ QJ -H
i e n, u
: hj 0s (o «j;
■u T> u. a:
h c t
i 'Q tJ
O, U
ss
A -J •> O I
•* I ~ O -
»-r r - z r - - u. u ~
0.3 3 CL 03 3 IN «■* _| 3 - a
OCZ Z r CD Z Z INO-IA — OXT
i- x o x o: 3 i- > ►xcxoanAvQ. j . j
Z UJ - UJ - UJ - N UJ - UJ - - - N - A X _l U.
w Z A Z (J « O > ZZAZ_IXCJ~<I~~X~
uj ro « <r
u <r A A
« - *4
0. UJ - 3 N N
cnaci-ujzuz
Q.U. CL UJ
r 3 o. z
3 A *-s
~i CL * * * _J
OOOOOOOOOOOOOOOOOOOOOHW
'0N0J0>owNn^in'0MD0>OHMnvin<i>0'0
iNfNiNfNoommcDooiiicriajcDCDo*0'i>o*o*0'0*o*o*
CM CM CM CM CM CM CM CM CM CM CM CM CM (N CM CM CN CN CM CN CN CN CN
roooooooooooooooooooooooo«M(Nioooo«Hro*-oooooo*-4CNi*)ooooooooo*-4
*oNO<^o»-tCNW^in'ONa>©*©^CNr»)^'in'ors.coO'0*o*0'©~«CNCNCNCNm<rm'OfNcocooooo©‘©»-»CNm<rin'OfNiN
(MHMhOoooooooooHHHHrtHHHHHHHHNNCNr'iNNNNCNtNNCMf'iCMNCMnnnnnnnnn
CNCNCNCNnMnnnronnwnronnnronronwmmronnromnnmnnrnrornnnnnnnnnromnnmrn
* 0 ^- *r n <t * <r
m *h ^ o cn in m th ^
*HO © H H m o o o
in in rN in
H rt O H
w ro ^ n
>o *o *o *o
rs in in rv
© © o ©
in in in >o o in rs
-< in *-• rN <r ^s o
HlOfOIOOlOH
* c-j >o *■« n in ©
O O © H H H f'J
CM CM CM CM CM CM CM
"O *0 -O >0 >0 >0 >0
rN in rs rN tN in in
© © © © o © ©
in in o >o cm >o
*-• ut <r rs
ro ^ y* © © i-<
sr in *o © ro
rg cm cm cm ro ro
CN CN CM CM CM CN
*0 *0 *0 *0 *o *o
rs in in jn rs in
o © © © © o
CN *4 CM
*o >o <r <r
© ^ © ©
^ rs o ro *o *o
ro ro <r <r <r
CM C J CM CM CM CM
*0 *0 *0 >0 *0 *0
fN IN fN IN IN rs
© O © O o o
in >o m *-i -h
<r rN in >o <r
ro o ro ro ©
NOhOO
ro o © © in
ro © © © cm
>o ro >o ro in ^
rs CM fN cm
o ro o ro ro ro
© >o «-» cm o rs
rN rs o in rN ro
ro ro © ro ro ro
in^'cminoincN*-*
HCNNHnvrjOH
roooroooororo
ro ro o roo ro ro o o o o ro ro©ro o ro o ro ro ro roooroooororo
'0'0©CM^-'OrNo^cMro'r'orNocMroin*oo»-tro^-'orNiNrNNCM'rininininrN^iroin©^sH^^i5rrN^^iniN©ro^-
'rtininininin'0'0'0-0'0'0>0NNNNNoooooooooHHHHHHHri(Mf-jnnnnnnnM'<r<rviniiiyT
r-JCMCMCMCMCMCMCMCM cm cm cj CMCMCMCMCMCMCjrororororororororororororororororororororororororororororororororo
'O'C'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'OMJ'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O
NfsNNNNNrLNNNNNNNNNNNNNNNINr^NNNrNNNr'NNNNNNINININrNrNNINNINNNNNN
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
Number 24
164
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 17
2 ' ' UJ 2 Ci
OONH u 1-1 oo
<r u <r a
- •• o - z> n. - o - cc a: o-
u«o«t-tn<r«i»u uj hh
u.
_i _j m u.
■J -J 2 3
ccoccQ^coiQii a cn in
T JTJUUJQ J1 Q Q
»-
3
U. U. U.
UJ CM 2 3 3
2 h- uh iXi 1 X 1
2 2 ^ 2
<X O * * * A m
oooooooooo*-«cmmoo
HfJM^in'ONDBO'OOOOHN
'O'O'O'O'O-O'O'O'Oi^rsrsfsr^rv
'r<r<r<r^r*r<r<r<r»T<r<r<r<r’r
'On>o^'Hin>omjTinnov' 0 'Oor)Hn©N*r<rfjvN
OUTM'OUTinMNMNrOfJ'OfJOin'OOHNwCJNVf'IN
h ri rj n o h ri rj f'j n o o h rj ruj n n to o h h n n n
cm ^■<r«r<rinininuoinm' 0 ' 0 ' 0 ' 0 ' 0 ' 0 ' 0 ' 0 ' 0 r , sfsr^rsr > sr^
© r\r\rsrsi\Nrsrsrvrvrsf\rvrvrvrvrvr\iNrvi\i\rvrsrv.
©oooooooo©oooooo©oooooo©oo
t r £
2 *- Q O 23302U.
OO X 32 KHU.IlU.h22 © 2 h 3
2 <t H- UJ Q CL CM O O O 0 1333 V JQHI-t-<[tt
O J0X2bl2HnIiijH>.22iBiSaiUJ«HUJX<02
2U.22<IZU.>-ZlflK2>-HfllXHm25I02t<lH
ooonoooo^MinNNfjN’OO-ON^VHn^Nir
n n n h Mn h n r-j <o f j o in r j >o <o n o iii h rm n h in
n o h n m o h h nn n o o h h cm cm ri n n o h h m n n
© ^■<r<r<ruTUTioininin'0'0'0'0'0'0'0'O'0rvfvrsisrv.rs
©rsrsrsr^rsfsNNNrsrsNrsrs.r^Nrvr , srvrsrsrvNrsr , v
© 00©©000©0©©000000©00000©©
UJ X OZKU) h
W Q (J 2 23 UJHH 3 U.
(J CC O UJ >- <X U.U.UJC 2 AUI(nQ 3
« NOt-UK 0 . ^ in LH(J 3322 X 2 QO 20 J
iLhZ 2 UJUlNHrtiLKHX 3 W 0 aiaHMUi 303 Hil.
nmzuaizxzjuzxuixocQjiLZZCi-aiai
V 'l -V 'J -v UJUJUIUJUIUlUIMJ'g'O'O'O'OSJ-OIMNMVMN
© rsrvrvisNrsNr^rvrsr^rsrsrsf^fsisrvrsNNisrvNfv
O 0©©©0000©0©©00©00©©©0©©0©
a 3 CL H
<x 2 3 <1 2 U
O I- a 3 wIl1lU.2 0'ChCD CM
J H 2 2OOK^IDt0UJC333UhXZHhh
>h2UJO<T-flyHu.KHHOIOi5iS«<IXUJOX33
HU131flUZZtnZJIiJZZLinjLNu'ifi2Z2ZOO
o n h w o in © in
©>o©'Orsrs in cm
© cm o cm m m mom
O'OO-oininHO'OM
r^rvMr^»H*HisM©©
OOOOMM^HOOM
•oon^'OH«rinNH«r<r'r'rN
rjMMMM<rccvininininiiiN
MMMMMMMMMMMMMMM
f\rv.rs.f\rvrsrvNr\r\r s sr\rvrxr\
rvrsrsrvrvrsrsrsrsr^rvrsrs.rsN
©00000©0©00©©00
'OO^HiniO'O^WinONHN^O^OVH-ONHINH
uTinoiniN'Oino^roMM'OMMini^oMO'OMoo
UNhNNMOhNNMMOOhNWNMMOOhNM
o -H<r^-^-^‘inininininin«O' 0 ' 0 ' 0 ' 0 ' 0 ' 0 '<jr < sr^r^r'.r^
O ONNNNNNNNNNNNNNNNNNNNNNh
O 0©©©00©0©000000000000©0C
X X K O
cn u uj cl r
KhU.U.u.iCIIK3W
Q(L33IUJXh03
mwvuu U- LL -»v uj rj ILru.U.U.XLLILJU,
2<r >u.roujino 2 n h n Qa.332u_jxi-or
>-ac ujAKi-zini(hHa.uH>-zxiiiCD3«cLJZi-
tnuj ^Ni(n«z(flziLJozxH#>-i-)a^zHmii
<rin»-iOfsrsMMr^^orv
MhCIhOhOh^Oh^
hCMOMOMOMCMCMMCM
cm n cm rs in
0 rs rs cm
© M M O M
in'OOMninw
hMTNhNh
M M O M M M M
in'OO'OO-OOMCMM'O^H'OO-Oin'OM
HNWMiTMi-JO'OONVMnNHOO
MMOMOMOMOMOOCMOOMOM
imfiNHMinNH^Nfj^NONVNH-
<r <r -o in in
o © rs CM
Oh O M
W in N in >0 M
»h m m ^ 0 0
M M uj M O M
*r <r ^
’H CM -H uH
O *-* O o
M li") CM ■uj
in © OO
CM O ©
<o >o cm in
O OMM
’H O M
m v •<) o o <j <h m in <0 n h m tkj n iii n h m iiT i\ u «r n n n 0 n v n h <r v »r <r n h n n nh n cn n m
MMMMMM< r<r^^'<TiniiTiiTiniiTinin'0'0'0'0r v srvr s soo©’-i^H’-<»-<C'jr‘'jr'irjCMrjMMMM^'<r^r , T<T
r r r r r r ^ r r r r r r r r H r H H H rt H h n n n n n rKKKj ri n r * rj r * 01 ^ ri ^
rsrsisrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsfsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrsrs
rsrsfsfsrsisrsrsrsrsrsfsrsrsrsrsrsfsfsrsrsrsKrsrsrsrsrsfsrsrsrsfsrsrsrsrsrsrsisrsrsrsrsrsrsrs
©©©0©00©0000000000000000©©©©00©00©00000©©00©000
Page 18 I
MnNmiTMnNMH-coMnoH^ijmin'flM
(MHMHHOHHio-OMniiTinMHMHMHOO
-hMjhMM*-*M-iMMMOCMM©O^M»hM©M
in >0 N N
-« O O ^
M O O »H
•ONNM'OeiNin'ONONVinNHlMM'ONN^NNNNCNI^in
^■vinii‘)in'0'0'0'0'0isr^r^.rsrso©©©©'»-i»Huj»H^»j(MCMCM
CMCMCMCMCMCMCMCMCMCMCMCMCM CM MMMMMMMMMMMMMMM
fsrsps.rsrsrsrsfsrsrsrsfsNfsrsrvrsrsrsrsrsrsrsrsrsrsp\rvrs
rsrsrxrsrsfsrvrsisrsrsrsrsrsrsfsrsrsrsrstsrsrsrsrsrsrsrsrs
©00©©©0000©0©00©©000©©©000©0©
Dr. Dobb's Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, CA 94025
Number 24
EXIT THIS REVIEWER
Jef Raskin
Director of Communications,
Apple Computer Co. Received: 78 Jan 19
1 have accepted employment with APPLE Computers, Inc.
It is a case of putting their money where my mouth is, and
now I will have a chance to apply my criticism from inside
a company. Since I will be Director of Publications there you
will know who to blame if, in a year’s time, their manuals
aren’t up to snuff. Some other reviewer will have to judge
if I’ve succeeded.
This (except for a few that are in the works and may
appear in print after this one) is my last review. I will probably
continue to write opinion articles, but will no longer cling
to the mantle of objectivity. At the end of this article I will
have a few words to say about my new employer’s products.
But on to a review. A reader called and asked me about
Electronic System’s kits. He pointed out that the company
looked fishy, having a Santa Clara phone number and a P.O.
Box in Burlingame (Box 212, Burlingame, CA 94010). No
street address is given. Burlingame is in San Mateo County.
I told the reader that I would find out what was going on.
I called them up, and after evading the answering service to
talk to the real wheels, found out that the separation was due
to their desire to keep a continuity of address for their
customers after they had moved. Fair enough. They use a
box rather than a street address to prevent their being ripped
off (which apparently has happened once). They went a
bit further and agreed to send Dr. Dobb’s a small kit for
review. Any company brave enough to do that can’t be all bad.
Their catalog is labeled: “Hobby Computer Kits”, but
should be subtitled: “mostly for those with a strong electronic
bent”. These kits are not for beginners, nor are they intended
to be. In fact, Electronic Systems prefers to just sell boards
for most of their kits. You can scrounge up the parts, follow
their schematic, and modify away to your heart’s content.
The kit I got was their RF Modulator. It’s $13.50 with built
in power supply and regulator (to run off a 12VAC center
tapped transformer, 8 volt unregulated supply, or it can run
from a regulated 5 volt supply) and with the parts supplied.
Almost. The obvious unit for comparison is the Pixieverter.
The Pixieverter (which works fine) requires —6 volts which I
find sometimes hard to come by in my TTL breadboarding.
So I appreciate Electronic System’s choice of operating
voltage. It also makes their unit a very good buy for the
money.
There are no “put square peg 1 into square hole 1... ”
type instructions. Just a schematic and in this case, a slightly
off-register but clearly silkscreened parts placement on the
printed circuit board. Layout was clean and professional.
I discovered that C7, a 3Pf capacitor was missing from their
parts list in the catalog, on the package, and was missing
from the kit too. Consistent, at least. Unfortunately, the
schematic and the circuit do require C7. I didn’t have any
in my parts box so I just twisted a 3/8 inch pair of solid
insulated wires together to make a capacitor (what Hams calls
a “gimmick”). 3 Pf isn’t much capacitance, and any two
conductors in the same room together have some capacitance
between them.
You have to wind a coil yourself. There is a note telling
you how to do this:
COIL —3 3/4 turns of 22 AWG wire wound on a no. 2 pencil.
I quote this exactly. If you can’t recognize a piece of 22 AWG
wire you shouldn’t be building this kit. It just refers to the
gauge of the wire. You also should know that this wire gauge
is not too critical. If you get a finer gauge, the coil will be
rather unsturdy, but will work. A little heavier wire is OK
too. The kicker is the specification of a no. 2 pencil. Since
the pencil does not become part of the circuit (it is just the
form for the coil—although they doen’t say so) it is unclear
just what difference the hardness of the lead makes. What they
meant was to use a standard 5/16 inch thick pencil as a form
for winding the coil. A 5/16 dowel will work. Again, this kit
is meant for people who will automatically figure this out
for themselves. No hint is given as to how to read the values
of the components given with the kit. The components seem
to be of acceptable quality. The capacitors that were supposed
to be Silver Mica were indeed of that type.
While I do think that Electronic Systems could be a bit
more careful in their documentation, I believe that there is
a place in this world for kits such as these, where one can
substitute knowledge and experience for money. These kits are
inexpensive, and in this reviewer’s opinion, a good value.
Those who are not in a position to figure out sparse
instructions will have to pay more elsewhere. Many of their
kits seem fascinating, and there are a number that seem
downright handy. They have a UART and baud rate generator
kit for $35.00 (board and schematic only $12.00), a modem
kit for $27.50, a very appealing RS-232 to and from TTL con¬
verter kit for $7.00, and some others. Write for their catalog.
Electronic Systems also offers a memory board and their
TIDMA—which is a Tape Interface Direct Memory Access
board—which only comes assembled and tested. It sounds
fascinating , but you will have to write to them for details.
Their catalog contains schematics, and is quite educational
if you know which squiggle means what.
I promised a few words about my new employer’s
computer. The APPLE: it is a very neatly packaged 11 pound
computer that is unusually complete. It uses a home TV
(preferably color) for output. It comes with built-in speaker
and joysticks and the associated interfaces, and with a built-in
cassette interface. The keyboard is built in as well—and it is
a pretty good keyboard (compared to the PET it is an
excellent keyboard). BASIC is in ROM and comes up at the
press of (three) buttons. The APPLE is fun. But it is not, as it
stands, too serious. You can’t (from within BASIC) store data,
but only programs on the cassette. The screen is upper case
only, so you can’t do text editing. The BASIC is integer only,
so you can’t do business or most scientific applications—
although APPLE does provide a floating point BASIC on
cassette. It is called “APPLESOFT” as it was written by
Microsoft which has provided so much of the personal
computer software. Both APPLE BASICs provide color
graphics in an easy to use form, which is one of the chief
charms of the machine. It is probably the best computer
around to use to teach programming in BASIC.
The hardware is especially good, it is a very reliable
machine, as I have learned in some 12,000 miles of traveling
with one in its optional leatherette (i.e. plastic) carrying
bag. The switching power supply is both light in weight and
more than adequate, and I have had no overheating problems
at all. You can’t even warm your hands with it in a cold
hotel room. Unlike the PET which limits you to a measly
8K, the APPLE II has room for 48K of RAM inside the
little box, and upping the memory merely requires changing
three jumper blocks and slipping the appropriate chips into the
sea of sockets provided. An 8K APPLE costs $995 compared
to the $795 PET, but the PET does contain its own cassette
recorder and video display. My thoughts on the PET were
published in the September/October (1977) issue of Personal
Computing. The APPLE II is a lot classier.
The existing APPLE II documentation is very poor. But
this is what I am trying to change, as I said. I think the APPLE
has a lot of potential, otherwise I wouldn’t have gone to work
for the company. It’s not on the S-100 bus (it’s not 8080 or
Number 24
166
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 19
8080 QUICKSORT
by Mike Gabrielson
P.O. Box 2692
Stanford, CA 94305
1
d
3
* QUICKSORT
- *1*6
GAPWIELSO* - 12/1/77
* ACCEPTS!
A = ADDRESS (iF FIRST RECORD TO SORT
5
Hi s ADDRESS OF LAST »E10WD TO SOwT
7
* UUlCK
IS A
RECUR
SIvE ROUT INF. . . .
9
PRUCEDURE QUICK (DE, hl)
1 0
IF DE
>: ML
Then WETURN
1 1
else
PARTITION TP FIND K
Id
QUICK
(K + l »
HL)
13
QUICK
(DE,
K-l)
1 m
RE f uR
*
16
* partitioning swaps data and produces an addkess k.
1 7
* DE < =
K <s
hl, SuCw That ALL DATA TO ThE LEFT OF K
16
* IS LESS Than ThE
0 A1 A AT K, AND DATA TO THE WIGHT
1*
* IS GREATt*
. THIS IS DE SCRIBED IN VOLUME 3 OF knjIh
20
* ThC ROUTINE IS CODED FOP SORTING ONE bYTE RECORDS,
21
* BUT
HE SI
x comments indicate rhat to change to sow
2d
• RECORDS OF
OTHER
LENGTHS.
dl
2u
ouuo
4
C03200
QUICK
CALL
UE_HL
2b
UUU3
do
RM
do
OOOM
05
PUSH
WO
21
0005
E5
*>uSh
Rh
db
U006
N
CD3POO
LOOP
CALL
DE_hl
2 9
OOOv
w
DA 1F 00
OL
RIGHT
30
O00C
N
CJ5D0U
CALL
SwAP
31
OOOF
13
LEFT
INCP
WO
1 - make DE POINT
$ 2
0010
K
C D 320 0
CALL
DE.hl
TO NEXT RECORD
33
UUl 3
ft
CA2600
9E
FARTED
3*
Ud 1 6
W
CD 3800
CALL
OE_hl
3b
U 0 1 9
N
uAOF 00
6 L
LtFT
3e
ouic
N
CD3800
CALL
Swap
37
UU1F
2H
RIGHT
DE CP
RH
2 - make HL POINT
3b
002u
W
CD320 u
CALL
DE_hl
TO PREVIOUS RECORD
39
0U2 4
K
C20600
«NE
LOUP
MU
uu2b
E3
PARTED
*ThL
Ml
U027
1 4
INCP
RD
3 - MAKE 0E POINT
M 2
0028
W
COO 00 0
CALL
QUICK
TO NEXT RECORD
m3
0028
tl
POP
NH
UM
002 C
26
UECP
Rh
M - MAKE HL POINT
Mb
U02U
Dl
POP
RD
TO PREVIOUS RECORD
46
002t
R
CD0000
CA(.L
QUICK
iil
0031
C 9
Rt 1
MV
0032
7A
Ct.HL
LH
W A , RD
COMPARE DE TO HL
50
0033
bC
CR
R A , w H
51
0 0 3m
Cf»
RNfc
5 2
00 35
7o
LR
nA,RE
53
003b
bO
CR
ra,«l
5m
0u 3 7
C 9
RE T
55
*
5b
0U3t*
1 A
DE__HL
L 6 A
hO
5 - COpPAWE kE CURDS
57
0039
bt
C
nA
POTNTFD Tu bY DE# hl
5b
00 3*
C9
WE 1
5V
•
60
0U3B
1A
Swap
Lb A
wo
6 - SWAP RECORDS
bl
U03C
Mb
Lb
Mb
POINTED TO ttY OE# hl
b 2
0030
77
STb
W A
63
0U 3E
7H
LR
H A,RH
6M
O03F
12
ST A
WD
65
U 0 4 0
C 9
WET
#>b
•
67
EnD
Z-80 based so it wouldn’t be anyway) and there aren’t a lot
of accessories available for it yet. On the other hand, it comes
with more built in than any S-100 computer, e.g. color
graphics a la Cromemco’s dazzler, A/D to run joysticks (and
it comes with two single axis sticks), cassette interface, BASIC
in ROM, programmable louspeaker output, keyboard, room
for memory expansion without buying boards, etc. So it’s a
toss-up in that regard. I am not getting rid of my S-100
computer.
I expect APPLE to come out with RS-232 interface,
upper and lower case display, floppy disk interface, and all
the other goodies that I can put in my Poly-88 (which, dear
fans, still runs great).
I would like to thank the hundred or so readers who
sent in helpful letters spurring me on to write more reivews,
and the three or four who gave me hard, but useful criticism.
Thanks to Jim Warren for putting up with me, and to the
neat people at People’s Computer Company who publish
this Journal. And a big thank you, and my admiration to
the many manufacturers who sent us equipment for scrutiny*
and hope that the new reviewers) get as much cooperation
as I did.
ELECTRIC PENCIL WORD PROCESSOR FOR
NORTH STAR DISK
News Release Received: 77 Dec 28
The Electric Pencil character-oriented word processing
software allows text to be entered and manipulated at any
location as a continuous string of characters. Lines are format¬
ted automatically. Features include cursor controls, global
search and replace functions, bi-directional scrolling, right and
left justification, wrap around text as well as character, line
or block insert and delete. Page formatting is at the control
of the user. The Electric Pencil has its own DOS. Storage and
retrieval of text is simple and automatic. Six versions are
available for North Star including SOL-20, VDM-1 or VTI
videos, standard printer (TTY, etc.) or Diablo HyTerm.
Minimum system hardware for 8080 or Z-80 micro is 12K
of memory, printer plus interface, video monitor plus VDM-1
or VTI interface, North Star Disk and/or Tarbell or CUTS
cassette interface and recorder. Available from local dealers
or from Michael Shrayer; 3901 Los Feliz Blvd.; Los Angeles,
CA 90027.
PERCOM CIS-30+ CASSETTE
INTERFACE TO MITS 680B
News Release Received: 78 Jan 13
Percom Data Company released technical memos describing
how to use their standard CIS-30+ interfacing unit with the
MITS 680b computer. Long used with the SWTP 6800, the
CIS-30+ interfaces two cassette recorders and a data terminal
to 6800-based microcomputers.
The CIS-30+ provides user-selected cassette data rates of
30, 60, or 120 bytes per second, and data terminal rates of
300, 600, or 1200 baud. The two cassette interfacing circuits
are independent and operations such as cross filing therefore
are possible. Optional program control of recorders is available.
Cassette data recording is KC-Standard/Bi-Phase-M
(double frequency). The data terminal communication mode is
full duplex.
The MITS 680b PROM monitor may be used for loading
and running programs, except for flipping the tape switch to
ON for program loading.
The CIS-30+ sells for $79.95 in kit form, and $99.95
assembled and tested. An instruction manual is included. For
MITS 680b applications, users should request PERCOM Tech
Memo TM-CIS-30-09, “Using the PERCOM CIS-30+ with the
MITS 680b Computer.”
Optional accessories include an IC socket kit ($4.95), a
Remote Control Kit (for program control of recorders)
($14.95), and a test cassette with operating software ($4.95).
Contact PERCOM Data Company, 318 Barnes, Garland,
Texas 75042; (214) 276-1968.
Page 20
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
167
SMAL/80 BUBBLESORT
SMAL/80 MACRO-ASSEMBLY LANGUAGE
FOR 8080 AND 8085
News Release Received: 78 Feb 6
CHROMOD Associates has announced the development of
SMAL/80, a compiled, structured, macro-assembly language
for 8080 and 8085 microprocessors that requires 7K of
memory.
SMAL/80 statements are written in a symbolic notation
resembling PASCAL and PL/M that simplifies the writing of
assembly language programs. SMAL/80 also incorporates the
basic structured-programming constructs, the DO-END,
IF-THEN-ELSE, and LOOP-REPEAT, which may be com¬
bined with and/or nested within each other without limit to
form complex statements. The code produced by the compiler
is as efficient as that written in a traditional assembly language
by a skilled programmer.
The SMAL/80 package includes a 2K macro preprocessor
written in SMAL/80 that extends the usefulness of the lan¬
guage. The macro preprocessor permits conditional expansion
of statements, unlimited nesting of macros, and has a natural
notation.
Also included in the SMAL/80 package is a translator pro¬
gram that allows one to convert any 8080 or 8085 program
written in standard Intel mnemonics into SMAL/80, but with¬
out the constructs.
SMAL/80 is a revision of SMAL, and 8080 language
developed by Dr Charles Popper at Bell Labs. The original
SMAL was implemented via a SNOBAL preprocessor running
on an IBM 370/168. SMAL/80, also developed by Dr Popper,
has been redesigned and can now be compiled directly on any
8080, 8085, or Z-80 machine.
SMAL/80 is being offered initially in CP/M and ISIS I disk
formats. Price, including documentation, is $75. In the near
future, a Z-80 version of SMAL/80 in the same disk formats
will also be offered, as will various relocatable tape cassette
formats that incorporate linking loaders.
Write CHROMOD Associates, P.O. Box 3169, Grand Central
Station, New York, N.Y. 10017.
STANDARD BUBBLESORT
SI7E:
E0U
255
;max size of ARRAY
LOOP1:
MVI
D,0
;reset "switched" flaa for
;i teration
LDA
N
MOV
B.A
;number of list elements
LXI
H,ARRAY
LOOP2:
DCP
B
J7
NEXT1
;no more pairs left
MOV
A.M
;first element of pair
I MX
H
CMP
M
OP
LOOP 2
MOV
C,M
;do an interchange
MOV
M,A
DCX
H
MOV
M,C
I NX
H
MVI
D.l
;set the "switched" flag
JMP
L00P2
NEXT1:
MOV
A,D
ORA
A
JNZ
L00P1
HLT
N:
DB
SIZE
ARRAY:
DS
SIZE
END
SIZE EQU 255
LOOP;
0 = 0 /* reset
A = M(N);
B = A
HL = ARRAY;
LOOP;
IF —B ZERO
BREAK;
A = M(HL)
++HL;
IF A : M(HL) NEG
THEN DO
C = M(HL);
M(HL) = A;
-HL;
M(HL) = C;
++HL;
D = 1
END;
REPEAT;
REPEAT WHILE [A = D; A = A
N: BYTE SIZE;
ARRAY: RESERVE SIZE;
END PROGRAM;
/* max size of ARRAY */>
"switched" flag for this loop
iteration */;
/* number of list elements */;
/* if no more pairs left */
/* first element of pair */;
/* an interchange */;
/* set the "switched" flag */;
A] NOT ZERO;
ADAPTER DOUBLES DECWRITER SPEED
News Release Received: 78 Jan 23
The Larks Accellewriter™ adapts any LA36 DECwriter to
operate at 600 baud. The adapter converts the standard 110/
150/300 baud DECwriter to 110/300/600 baud. It changes the
internal timing of the DECwriter and causes it to print at 60
characters-per-second. Installation typically takes less than
one hour and requires the removal of two integrated circuits
from the logic board of the DECwriter. These are replaced
with low-profile IC sockets. The Accelewriter is then installed
in the board in place of the two original IC’s, and the logic
board is reinstalled in the DECwriter.
The DECwriter can be reconverted to its original electronic
configuration by unplugging the adapter and installing IC’s of
the original types in the sockets. This takes less than one
minute and requires no tools. The Accelewriter causes no per¬
manent modifications to the DECwriter and does not interfere
with the installation of standard DEC™ option boards. Price
is $95 and delivery is from two to four weeks. Installation is
available in selected areas. Contact Larks Electronics and Data,
Box 22, Skokie, IL 60077; (302) 677-6080.
Number 24 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
168
Page 21
A Line-Oriented PILOT Editor
BY DAVID J. MORGAN
University of Texas at Dallas
P.0. Box 688
Richardson, TX 75080
Dear DDJ:
I have written a line oriented editor for Dr. Starkweather’s
PILOT ('DDJ, April, May, 1977). My program takes an
additional 629 bytes of memory and provides nine editor com¬
mands.
The attached program listing shows the assembled output
and assumes that the PILOT source program (as shown in the
May, 1977 DDJ,/ has been assembled with it. User documen¬
tation, in the format of the April, 1977 DDJ PILOT documen¬
tation, describes the operation of the editor. Thus, the routine
can be implemented by assembling my code at the end of
Starkweather’s and filing the documentation in place.
Interfacing to PILOT is easy due to the modularity and
well planned design of the original program. The steps are
as follows:
1. Since we are extending PILOT we must change PBUFB
which indicates where the user program area starts.
Change the following line (originally the sixth line of the
program on p. 18 of DDJ, May, 1977):
PBUFB EQU 1000H
to: PBUFB EQU 11A7H
2. Change the JMP in the vectors (so that when the user
enters edit mode the machine does not jump to the
monitor) from:
0112 C360E0 EDIT: JMP MNTR
to: 0112 C3EA0E EDIT: JMP EDTR
3. Similarly, change the following:
0309 C360E0 JMP MNTR
to: 0309 C3EA0E JMP EDTR
My routines call Starkweather’s I/O (DSPLY, CHI, KEYIN,
CHO) and his block transfer routine (BLKTFR). I also pickup
the EBUFF address (the entry buffer address) and PBUFE
(End of user program area) as set by the programmer (p. 18,
DDJ, May, 1977, 7th line). Any alterations made to any of
these routines or addresses should be transparent to my
program. That is, it should run anyway.
I also have implemented the PILOT command LOAD: for
loading a PILOT program from an iCOM disk (and construct¬
ed with iCOM BUILD or EDIT commands) running with
FDOS-II and a TIME: command for use with a Comptek (now
Canada) CL2400 real time clock. I’ll be glad to send these
routines to anyone who wants a copy. I’ll also send the editor
routine on a diskette if you send me one to write on (iCOM
compatible) but I guess I can’t include all of PILOT on disk
because of the copyright.
Sincerely,
David J. Morgan
Assistant Professor
P.S. Please mention that Binary Systems, Inc. of Richardson,
Texas (The Micro Store) was good enough to let me use their
machine and a new ribbon to produce a hardcopy output.
They are pretty good people.
After invoking the PILOT EDIT: command the system will
respond:
PILOT EDITOR READY
If there is no current user program in memory the system will
then display:
PGM SPACE EMPTY -ENTERT OR ‘E’
indicating that the user must either insert text or exit from the
editor. The system will then prompt the user with an asterisk
(*). After the prompt is displayed, any of the following editor
commands may be entered.
B Backup the line pointer. This routine backs up the inter¬
nal pointer to the previous line of text and then displays
that line. The previous line of text is then made the
current line. If this command is invoked when the
current line is the first line of the program (and hence no
backup is allowed) the message:
-START OF FILE -
is displayed and the current line is left at the first line of
the program.
C Display the “current” line of text. When the editor is
entered from PILOT and a program is in memory, the
current line is automatically set to the first line of the
program.
D Delete the current line of text. The current line is re¬
moved from the program and all following lines are
moved up. If there are no lines left to delete, the
message:
PGM SPACE EMPTY-ENTER ‘I’ OR ‘E’
is displayed indicating that a program line must be
entered or the user must exit the editor function.
If the delete is allowed, the next sequential line
becomes the current line unless there are no more lines
in the file. If no more lines exist in the file the last line
(before the deletes started) is made the current line.
E End of editing. Returns to PILOT mainline.
I Insert a new line of text. After this command is entered
the editor will respond with an equal sign prompt ( = ).
The user may then enter a new program line. The new
line will be terminated by a carriage return.
The insertion is made immediately after the current
line and the new line, once entered, becomes the current
line. If there is no space available to insert the line the
following appears:
- PROGRAM SPACE FULL-
The insert will not take place but no other action will be
taken and the editor will prompt for a new command.
N Display the next fine of text. The routine advances the
internal pointer to the next line of text and then dis¬
plays that line. The next line is then the current line.
The search for end of line is always to the carriage return
character (0D hex). If there are no more lines in the pro¬
gram to display, the message
-END OF PROGRAM -
appears and the current line is left at the last line of the
program.
Page 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
169
P Prints the entire program on the console device. This
routine will print the entire program exactly as a regular
PILOT command of DP: would.
R Reset the line pointer to the beginning of the program.
The first line of the program in memory becomes the
current line.
Z Reset the line pointer to the end (last line) of the pro¬
gram. The last line in the user program is made the
current line.
NOTES: It is imperative that all programs end with a carriage
return and a ctl/a (01 hex) character for the proper operation
of the editor. When entering programs in PILOT this will auto¬
matically happen if the terminator character (ctl/z) is not
typed until the last program line is ended with a carriage
return. If you are entering programs in the editor, it will auto¬
matically take care of this operation.
16K RAM BY NORTH STAR
News Release Received: 77 Dec 20
North Star Computers, Inc, announces a new, 16K RAM
board for S-100 bus computer systems.
North Star’s 16K RAM is designed for use in both 8080 and
Z-80 computer systems. It will operate at full speed (zero wait
states) even at 4MHZ.
The low-power board uses 200 ns dynamic RAM chips and
the on-board memory refresh is invisible to the processor.
Bank switching capability is provided and the addressing of
the board is switch-selectable in two 8K sections.
Another feature of the board is the availability of a parity
check option. The North Star 16K RAM board is offered in
kit form at $299 and fully assembled at $459. The parity
option costs $38 in kit and $59 assembled. For further
information, contact: North Star Computers, inc, 2547 Ninth
St, Berkeley, CA 94710, (415) 549-0858.
s
m
x t-
>- cj i
i z <r i
CL CC --
•- l- O U -C
LL J U <X
r <x x
a ZUIUlHh I— LUh u c
lu h3doi/i >■ inazo
io_i« a. ® a: hh z <x o
o om wo o o <t x
i h r uj h w i- h u. z x w uj
j io « in Ht-ouia:
J H H H Z H ouuio
IO 2 Z <XZUJZ U X O U x
atS H H I- H hllJH ho
Ch OCtUJ 0<XOUJXOOUJi20
- --H 0.Q.U) 0. W Cl O U ^ O O il m
T .► .* .» ... .. .. .. <. .. .. .►
O W Z »H CJ
! X h u a; I
: o cc o i
: a w o o >
j w w H
3 <X UI W Z CL
UUIhOC
1 H O * UJ
Ui CC « O
a cl r o uj
r >- h o h o
cu _j uiima
uju.hZu.zo. x x
- W •- >-<
i Ci i j i j i <r o
I* O H H
ClUmG
x o uj ui
«■ o
j x x u h r
.OOhZhO
) (J U ‘HdO.
i O O I J UJ '
UJ UJ oc z z>
►H o O
CC H CC u. <x
O o H H
U. X U. _J W CC
h oc H
(J « W
UJ UJ
Cl -I O
iouo
U I CJ
UJ Cl UJ
I Z I
CJ UJ CJ
z z cc a
►1 <x z
x
o cc a z <r r
zuizour
<Z K <X U I O
z r au
X UJ X CC UJ
O I O O UI0C
(J H CJ H U.O
►H H
CC X UJ Q UJh
o o x uj za
U. CC H HHUJ
U. UJ -J
Z H O h-
c n uj «x ouj
c o co au
o >- x x
0-1 O LlO
OC CL W u _JU
- CD X Ci CC Ci
I Cl U UI OUJ
X <x
<r cc
cc o
O O l
o cc :
cc a. ►
CC ' CC - X ' O' CC '
JuClOZUIACOJm
UI' O' Z ' O' O'
CO
t— JC V
UI 1-0 -J
in ' (O' cnui cl
* Z OC UJ N C *• CO
HH ' CC - -IXO
H JHJH
x<xxxxxxoa.
> JO J(0 JCDJXO
J JO.
n <x <r x
-> O O 1 •
hh _J _J _J —I Cl
X<X<t«XXXOi
• jooojana
Cl — — —
I-H Cl O.
CL N CL N O X
OT070.1-
hjj<[ _i<r h
X <t <r H <EO UJ
• J OO to OJ cc .
rH Q O H-l »H »-l U.U.U.UJ
-H o O -I -I -I oooo
0> ON HH UIM'OO
n v o in <i in <i o oin -o u.
h o h n h n h ui u <r o o m
NONNNNNNU. OOOO
<XQOM'00>OU.O
UJUJU.U.U.U.U. U.O
UJ UI UJ UI UI UI UI UJ U.
ooooooooo
r-j in id o
oooo
u. u. u. u.
oooo
omoovou-in
n <r v cm in 'O <r <r
u.ouu.OHUjQHin».uooo
oooooHO«»<rn»rjN-o
niM'iinHNONoo^npioo
ritn voiniL«io(Mir)«n'ON
HQooHfinomnoonO'fioo
rjooo(NCNomin<rincN«r«-in'0O
ujh» NcoooNau.nMiiu.nv
OHHHHrtriMrutNi*)nnn<r<r
LU.U.U.U.U.U.U.U.U.U.U.U.U.U.U.U.
ooooooooooooooooo
lit N C O Ll O
—' O Q HOH
Hi O O O ^
O O' UJ U. * u.
CO VO u v
HQorto« o-
NOO noM o
m -o O' o u. cn m
in in in m in >o o
U. U.U. U.U. u. u
o o o o o o o
-I O O O U. U Ll U. t-1-hO
^O-^hhOOOOhh^O
in < o c uj * m m in co v u. o> o n « « uj uj a-
cninb vavui vcv cvuinoinwoov
ui<xuj<xuj<xuj<tuj<xuj<xuj<xuj<iw <r - o o-
U.OUOLlOU.OIlOUOLlOU.OU.OMOO
'Ooooooriinrscou.H^V'OO'iXiUJOfO'OO'
O^O'ONNNNNNNOOmCDCOIXIOOO'O-O'O'
U.I 1 .U.U.U.U.U.U.U.I 1 .U.U.U.U.U.U.U. Ll U IlLl
OOOOOOOOOOOOOOOOOOOOO
Number 24
170
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 23
3 H
3 3
Z x
V u
1 UJ
z l
o u
CL X UJ OC
H A <
3 z :
O UJ L
iC UJ fi A
A it Z Z
A UJ UJ O UJ
c x c
►— H 3 4—
4- « li. ZUJ
UJ A
UJaun-U.Ai£
1 W >- h Z iX Z
: <r z z a uj 3 h
j in h w Z u
uj u UJ UJ
■ AhK>UJ>l->
JZ3UJ<TI<TUJ<E
) < u. Q U1 U Ifl Q (/)
O (fi
K 0C
H
A Cl
a
<x z
u
U. M
AO
zcn
UJ UJ
z UJ
O 4-
Q >-
O 3 ~ CL
z <r 3 o
Z O X
X h Z
o
cn
>- >- r >
c c in .
Z UJ z o
o ► o -
H« JHI
m A Z UJ
OC A
A A
A <1
4— 3 h ^ 3 3 K
uj uj 3 <r o «i uj uj
(3 (fits in AW 2 0
z z 4- o z z
: uj a z uj uj
I 3 K U 3 I- 3
i o uj uj w <r uj <r
. I I O 2 (J) O W
ii UJ IT h C zr C X
(fi CL O - - 3 - - UJ
AHUJCt h u u x u
4- I- h Zh X
in cn c cn u *-< z <r r
z ^z-z- u - UJ
h I A A O h r HtuiuUI-
X Q£ 4-
3 U- C 4-
® K A U
3 Z 0- Z
U X W
z z r z
H H UJ H
3 X 3 4- 3
W 4- X
ZiCOL
0U30U.U
H 4- O X C
> U Z A
4— A Z (Z
Z Z U 3 Z
HhUUJhUI-
O UJ M I 3 H 3
a. cd z u iz z o
Cl T. XL
- - 3
X C X O L
CO A
C
3 X
Ll O
r a
to z
CL UJ
UJ C X 4- H h
z i- a
a uj ce in >->
UJ X Z Z O UJ iZh
x c h o x a o ►
CJ) UJ A
K I- A 3 3 C
UJ UJ Z J <T O
CO CO <1 Cl (Si J
4 3h 3
o o uj <r
Jttncn
' z x
ii h c
- o >- z
- X UJ X - -
uuzuacux
c a.
X IZ
3 X
ill-rt
Ul z o
M rj h pi
_J A ID A A ID X AO 3
N30.UH_JCL3H3X33il.33I X X C h 30.3 <1 3 3 I H _|
zoxzxcxi3ouxoxoxunuuao.no XO AOXUXC
3XU33U33XXX3XUX3X3AA3U3X 3Z**. 3X3X3 U
A AAA
3X333H
X Z X X X 3
- 3 H Ul 3 UJ o: •
H3XHNXI-
x o z a. z u uj
- 3 X H U -) A iZ •
h_jjcAiZ3hIh_jhCI—
3CCA3ZOXUXC3HUJA
-XUU3OHX3X3UXU10:A
ro n O'
CM AAPH
U N A A CM
N C A U X
P4 Cl CM CJ P-4
O O O O O
00 A O' V O' ■
V N A <
A n C L
u u cm r
ri in ao
hmm
o o o
A A UJ
m nn
o o o
o in *■
■ • j c n n h
bU N U N
ibPjn«iniiiD>uAijjii'H v inco
nfl-^-vwwTT^inin in in
ooooooooooooo oo
H u
o o
A *■
o- m
O' U A O h ^
inin moo >o
o o o o o o
4 S3 O
) a in
4CP4D-
J CM P4 U
N C A l
-O S3 -O '
o o o <
C ON
h UJ 4*3 UJ P-4 A O'
P-4 N P 4 X O P 4 U
in cd 0 * c u x o
N N N N N N 00
O O O O O O O
A U
O ©
a *r in
ro«o
UJ A A
O U U
x 0 - x z li¬
en uj uj u o
o u h u ui
CMHOOU
ii") t ui p-4 <r
h h u o r-4 n in u a
H O O m W W V + o
N AO-h A N O 40 in A
•« c O' in o p- 4 n c- in re
couu.Hja^aujpJO'Au.AH'OA
no'nTPJuiPJUMHuriw^^pj
JO'UAUJU.PJn-OO'AUAHinO'AH^-'OOOO'
immmpn(nfv.iviv.r>.iVft.ft.«T<T/T .ti » .r. ,r. iTi
l-
l
XH
O H
LL X
3X0
0 3 0
X H H
3 in
C 3
in x
X 3
3
Z
o o
z
H 3
X X
3 C (XI X
X 3 3 0
X X A X h
3 X U 4
O U <
Ul- Z
h z cn 4 - c (f)
Z U Z H 3300 U C 4- 1- X
O I- h >- 3 4- X H in
X HZ 3AU.3U.OH3Z3X 30
<D 033 O hOOOh^WUIX'i-
x a cn x i—i—3 3 x UH3 3
C» X XC 33- HXCZCZXH
331— - 3 3X3031- - 3OA30J3A>-
IXOOU ZHHXCn0003 O 3 X A A
hczw zen zuxhc
h- K H 3 - 3 Ah 111 H
U.X3 33300XXZ3X 3
h h CD OOAZZhhCXH O
3 U
C h
cn z
A A
Z A
3 C
X 3 3 X
C I- X Z 3
H > X 3 U Z
cn a h c
Z A 3
H H 3 U 3
333HOC
co o cn z o cn
H 3
I X X
J X z
3 C X A -
3 X L
o o
U X c
A A CZ C3U3:
©czoxoHcn c
C H A 3 O
HH HAAAZ3HK
33 O 3 3 A Z h C L
coco cococnccxcncnc
X 3
1 3 Z X i
: u c i- x i
J X X A <
JO z >- o
H o x O X I- C
: 3 h o >• o y
■ Z H X 3 X A
4 H H OC A3 2
13 O A X Z C
A I- Z I- U C
J 3 A C 3 O X 3 C
i 3 C U Z O X
z h cn u c
I- 3 H
u a cn
H 2 X Z
X 3 X 3
J C Z 4— X
3COXZC3ZU3
3 3X3 U U A 3
3 3 3 X Z ZCXX
H H A H HH H Z *—* —
• ZUZXZA3X3A ZC A X A -
Z X I h
h - A >
3 C O I i
Cl h C
H ' O > X
X - X 3 X
Z U U Z U A <
Z 3 X 3 Z C O
CJ X 3 O U - -
U 3 U Z U 3 A C
A CO A
h 3 X hji-
X X U X X 3
- 3 cn x 3 cn x •
X A A 3 X
___I3HNXNCXC3X33X3CXXHN4-
XOOXZZXZOXUCOXZXZI-XI-XUXCXOHZZXZL
3XXU3HU3X3XU I U 1 U T im W 3 A Ul U T X W h h u 1 ii
3 3HXN31-
X O X Z Z X 3
- 3 x u h -j cn x •
3H_|_JCAXC33 I C 3 h A
C3CCA3ZI-CX I AOOC
>uxgu3H)Hinucn'*3XXA
3 H D X
X X O X U
cn 3 X U 3
© H
© H
H PI
o in
H Cl A
P 4 PJ 3
rs o
c in
-• P-4 O'
P-4 P-4 U
00 A 3
c c c
XXX
O © ©
J X U P-4 U A P-4 X C A A l
J P-4 O- P-4 P-4 fO P-4 C A P4 A M 3 P-4 t*) n 3 P-4 O'
P4no-AUMAUO-p-4 30N3UAUtOUHpjp-4CMUUNHp-4HXUU
i^inoNC
© A H S3
in o x a
C 3 3 PI P-4 P-4 O'
P-4 Mi PI U P-4 U
3 H PI T in CD A
3 X X X X X X
X X X X X X X
© © © O O O ©
O O ©
X A U H
© O O ©
3 A <r n <r coino-
3r)C<K ANA
A 3 A A C O U P-4 A P-4
uouumo'foroup-i
UXh^-NCAUXCM
XXOOOOOOOh
XX0©00©©00
in co O' a
UXPIMT
h h n ci ci
o © © © ©
Page 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
171
TSC 6800 TEXT PROCESSOR
iZ Z
<r 3
t- o
W u
z z
u u
<x HH
A Z
_l CD Ci
JXI Jh
<iuuiuu)iocna
UuXUlCCuuuu
r t-htn
O CO U X
UZZli.
a hh o
5
i d
a m
o a. .
w-ou-a ucmau. u. h no- cj in © a a
H H H H V V V -9 H H I n V <T H H IN H o
~ — nu.nnaU'OO? unu.mo <r -« o h a h
~ — *r v in * o ci in c i in h h h n- o n t n n t t
Ui CM QOOCMQW^rsO'QO'OM’CMO'-HC-OM-O'U.LJ
— in ci cunm ci ci*rv*ro*ciinininociinvirir*
a ai tn ciO' anONaiijtfiujncNOno.OHaaujo.n'm.HQ w
uh u ecu fcMMTfcnT»»mirti()»fcTPirc»»T»»o o
'Oo-<iMUJU.ocMM'CDOovfMoiii.nrvO'Q'-iinthoujC'j'0«iijrc‘OrMiso
HHH-HHHinininini0'0'O.O'0'0NrsMNa>iDa)(Xia>0.0'0'0'<E«<l<lo
News Release Received: 77 Dec 15
Technical Systems Consultants, Inc. is pleased to announce
the availability of the TSC Text Processing System. This pro¬
gram allows the use of over 50 special text formatting com¬
mands. The commands included will support multiple spacing,
left margin control, indenting, the ability to save contiguous
space, save contiguous text, paging, right hand justification,
left hand justification, left and right justification, centering,
no-fill modes, page numbering, the printing of left hand,
right hand, or centered titles, and line length control.
Also included are capabilities for macro definition to define
and build special formatting commands, number registers
which can be used like variables in a program, conditional com¬
mand execution, setable macro execution points (to execute a
macro at a pre-defined line number), text diversion for later
use (such as footnote processing), the ability to prompt a
terminal for text during the formatting process, and a feature
which allows sending informative strings to the terminal.
The TSC Text Processor will also output numbers in either
Arabic, capital Roman numerals, or small Romal numerals.
Tab columns may be defined as well as the tab character and
the tab fill character. Environment switching is permitted for
easy parameter changing and a loop command is available for
repeated formatting jobs such as form letters.
TSC recommends the TSC Text Editing System to be used
in conjunction with the processor. These two packages will
give the user all the powers of the most complete word proces¬
sing system. As with all TSC software, the complete commented
assembler language source listing is provided as well as a very
extensive user’s manual which includes an “Introduction to
Text Processing”. Price of the SL68-29 Manual and Source
Listing is $32, with cassette $38, and $40 with paper tape.
Contact Technical Systems Consultants, Box 2574,
W Lafayette, IN 47906.
-J Z
O
H
z u.
iZ UJ
=3 Z
U HH
J H >- Z O X
UZUJ Ui o z
f-KKUJOiZKZ hh
Uu:uiXMOuj<xo4r
CD<XCDUZXCDXCDQ.
z 3 k o a
H « CC UJ HZ
o cn CL CD z «
t- UJ h- I- O
O O A <3 O <1
cc z a: cl z x z
) UJ O HH l-U
) N U. N li. <X
HH 3 HH CD A ►
u. o cn cn i
: hh z _j h z x i- c
: o hh o
J Ui H t- Z t:
j ui OUJ 1 L occ c :
j cn cd to hh a u. u h
Z D
3 <X Z
o cn a
z z z
U <X H H
HH UI iZ
z cd a.
0C U. I- z
*- <t o o
Z I z o z
UJ CJ iZ H- HH
iZ IZUli. c
cc cc «x hh a. cd
3 0 XU. 3 <X
U U HH 2
li. Z O Z UI
h- HH u H UJ 0 3
UJZHUJlUO<X<X
cDcnztocncDAcn
cc cc
: cc «x
< 3 X
u u
H- 3 y
UI C L
cd cn c
UJ iZ
i— Cl.
Z A
iZ I- 3 Z UlO iZ
U O O UI iZ H A
Z U O A
CC CC X z <x
CC O U UI o u
H-u.HHiuui<ctn
a. ►— xa «
z z z o
u.uozucnzui
X UJ O UJ 0 3
3IOhhXOhh<I
AOCDZOAZtn
Z H h- - A
N U. >
H- 0_l
x uj a.
l-<XI—>-K
cc a cn j o
XilZiZ
_l cn C O I Z <E -H 2 I o z JQJXJ
H -H H cn V h I-
o z z x j cc cn
z o _i o cn a. z i
hh c h <r h cn u i
_ICXA«-^AXAA'
K iZ >
O A J
ZCii
hh z cn
X -J A A
cn >-
x -I
CC Cl.
cn a cn
Z X X <z z
HH - A Z HH
_JXX<XOAX_J
z x x cn i in z
HH - AC •! HH
JCIOJAO JX _J
A _l A A
JJJXJh
x <r x z i uj
cn o _j hh cn iz •
JAllN3hhNhhJll
X3XZOu.ZX<tXA
-_JCnU3X03_l03A
X J J Jh
UXCCliJ
AinuuiZ-
HH J li. h
x <r o uj
‘ _j o u. iZ *
-JXX3hhNX_I»-
XOOOllZZIUJ
H_lAAX03HHcnZ>
A CD A A
JI J3XHNXHNX _J
XOXOZiZZZClZOI
•_IX_IXHHU3HHU3Acn
A
cn
A
O A O A in * UJ
uj uj n n uj uj n h a n
hU.CNUrsU.UNUU
uu.HmO'OoabiH
AAUUUUUUUA
oooooooooo
HAH
•H O -H
O 0> N
N- IS <C A UJ
A A A A A UJ
O O O O O O
<T O -O A
W N <T N
~H -H HO A HM Oin HHfl
*h h-h HHOHinnrjv h h o
N A h ACMMOAfl-OUA N UI D>
in o oou.tH(Nin?<ro m h?
C is u r-J A UI N A I*) A *HU-&'AANAA0'
no' a umi. un u un v <t t n r j nuuu
Nin'0IS«AAOW«00'A-Hina>AUU.Nin
UJUU 1 UJUUJUJU.U.U.U.U.OOOOOOHH
OOOOOOOOOOOO-l'H-H^’HTHrH-H
*H A
o
rs O'
ui o n in
CAAUJiurinriff.
N N N IS li. U N N U
in iii o n o n in
<C A 4 UJ m UJ PI IO UJ f I A n
N UJ M N n U. O H U. U N N
Number 24
172
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 25
NEW GRAPHICS BOARD FOR SOL
News Release Received: 77 Nov 15
KEA Micro Design of Toronto has annouced the availability
of GraphicAdd, a piggyback board for use in SOL computers
and VDM -1 Video Display Modules. GraphicAdd gives graphics
capability to these units (128H by 48V) and includes a SOL
ready-to-load software package.
Tlie GraphicAdd board mounts directly on the VDM and
SOL main boards. It works by replacing half of the inverse
video character set by bit-mapped graphic cells. Thus alpha-
numerics and graphics can be mixed on the same line. Mode
control options include fixed graphics, switch-selectable
graphics, or programmable graphics mode.
The software package contains a Graphics Driver, BASIC
Links, LIFE, and demonstration programs. The Graphics
Driver maps screen memory locations to H and V coordinates
with subroutines to designate black or white cells. BASIC
Links provide parameter passing to permit X, Y plotting
directly from BASIC.
GraphicAdd comes in kit form with all parts including
sockets and IC’s. Fully documented hardware and software
manuals (with all source listings) are included. Introductory
price for the GraphicAdd kit is $50. It is available from SOL
dealers or directly from Micro-Ware Limited, 27 Firstbrooke
Rd., Toronto, Ont., Canada, M4E 2L2..
DALLAS MICROCOMPUTER EXPOSITION
News Release Received: 78 Feb 22
The International Microcomputer Exposition will be held in
the Dallas, Texas Convention Center Sept. 29 through Oct. 1.
Co-sponsored by several groups, including the American
Association of Microprocessors, the Exposition will be
directed toward all levels of technology from the professional
engineer to the beginning computer hobbyist. In addition to
the seminars, a panel of experts will be available to answer
questions. Advance registrations indicate attendance in excess
of 15,000 to view some 250 exhibits. Further information is
available from Beverly Tanner;(214) 271-9311.
EPA’s LOW COST MINIPRINTER
news release Received: 78 Jan 3
San Diego—Electronic Product Associates, Inc. announces
the availability of the MP-44 MINIPRINTER. It is a simple
and inexpensive 5x7 dot matrix printer for microcomputer
systems. Electrosensitive paper is used to make copies at
speeds up to 88 characters per second with 44 characters per
line. Software control allows expansion of character size for
emphasis. Black characters are printed on aluminized paper 6
centimeters (2 3/8 inches) wide.
An enclosure 4 l /i by 8 3/4 inches houses the printer and
paper supply mounted on an interface board with all neces¬
sary components for connection to any microcomputer with
TTL logic levels. The microcomputer controls the motor
and print electrodes by an eight bit parallel output word,
and senses timing signals on two input lines. A power supply
of 40 volts dc at one amp must be provided to the interface
board.
Low cost is achieved by using the microcomputer for
software control of all writing and timing functions. The soft¬
ware is explained in a stmctured form which can be easily
implemented in any computer language, and examples of
complete assembly language coding are provided for micro¬
computers using the 6800 and the 8080 microprocessors.
Coding for the 6800 allows the printer to be operated imme¬
diately from the EPA Micro-68 I/O bus. Cost of this MP-44
MINIPRINTER is $257.00 and is available from stock. For
additional information please contact: EPA, 1157 Vega Street,
San Diego, CA 92110 (714) 276 -8911.
MUG MEETING IN SAN FRANCISCO
News Release Received: 78 Feb 23
MUMPS Users’ Group (MUG), San Francisco, California,
June 7-9, 1978 Jack Tar Hotel. Conference includes all-day
tutorials on programming in MUMPS, ambulatory care informa¬
tion systems, and technical aspects of ANSI-Stanford MUMPS.
Formal presentations of medical and non-medical application;
panel and discussions on applications on computers in medi¬
cine. Conference is the same week as NCC in Anaheim, Calif¬
ornia. Information: Ms. Pat Zimmerman, Department of
Biometry, Weam Research Building, University Hospitals,
Cleveland, Ohio 44106.
Page 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
173
In the last issue of Dr. Dobb’s we published the documentation and PL/M source listing
for the ACT 8080 Macroprocessor by Alex Cecil of Lawrence Livermore Laboratory.
Here now is the symbol table and the assembler listing. The table preceding the assembler
listing references selected line numbers in the PL/M version to the assembler listing. -TRW
BY ALEX CECIL
Lawrence Livermore Laboratory
An 8080 Macroprocessor
S00986
18
S00806
PFRN
S00984
5E
S00805
12
S00983
17
S00803
RECORDNO
S00981
25
S00802
SETFILERECORD
S00979
PRESETDRIVES
S00800
8
S00974
PRESETATIN
S00796
» • t
S00973
CH
S00791
DRIVE
S00903
7473
S00790
CH
S00902
7366
S00789
I
S00901
7A7A
S00787
FILENAMEPTR
S00900
7372
S00786
SETFILENAME
S00899
6C63
S00785
' 1 '
S00898
6E76
S00784
'3'
S00897
7766
S00782
PFVN
S00896
6674
S00780
PFFS
S00895
6E74
S00777
N
S00894
626E
S00776
BLOCK
S00893
7865
S00774
PFNB
S00892
6F69
S00772
PFDV
S00891
6F72
S00770
64
S00890
6F73
S00759
CH
S00889
7370
S00757
PFIO
S00888
6B75
S00756
N
S00887
6460
S00754
PFZZ
S00886
6472
S00752
PFMD
S00885
6664
S00749
PRODUCT
S00884
666D
S00747
PFML
S00883
6E72
S00745
PFSU
S00882
6663
S00742
SUM
S00881
666F
S00740
PFAD
S00880
6677
S00735
PFDD
S00879
6672
S00730
ENDPTR
S00878
7664
S00728
PFRO
S00877
6C6D
S00726
PFSO
S00876
7573
S00722
CH
S00875
6464
S00720
PFUK
S00874
7361
S00716
CHB
S00873
6461
S00715
CHA
S00872
6B70
S00713
PFPK
S00871
7373
S00711
* t
S00870
6367
S00708
60
S00869
7263
S00698
1A
S00868
6567
S00696
'DISK EOF S'
S00867
746E
S00694
20
S00866
6E69
S00691
NEXTCHAR
S00865
71 65
S00690
NOTCOMMENT
S00864
736E
S00689
CH
S00863
PFLIST
S00688
K
S00862
I
S00686
PFRS
S00860
CHCH
S00684
PFFW
S00859
PFINDEX
S00680
NOTFIRST
S00858
SECONDCH
S00678
PFPS
S00857
FIRSTCH
S00676
PFEX
S00856
CH
S00665
SEGNUMBER
S00855
BLOCK
S00664
CHB
S00854
BLOCKPTR
S00663
CH
S00853
NAMECH
S00662
LASTARGNUMBER
S00852
NAME
S00660
STACKOFFSET
S00851
NAMEPTR
S00659
PFCL
S00849
PROCESSENDFUNCTI ON
S00655
PFNT
S00847
PFRD
S00653
8000
S00840
RC
S00651
PFGE
S00838
PFRF
S00644
ARGC
S00830
21
S00643
ARGB
S00826
STUFFCH
S00642
ARGA
S00825
WRITESTATUS
S00640
PFEQ
S00824
I
S00637
PFCR
S00823
CH
S00625
CH
S00821
PFWF
S00624
I NPTR
S00820
19
S00622
PFI N
S00818
PFDF
S00610
M
S00815
PFCF
S00608
GCLENGTH
S00813
22
S00604
ANOTHERCH
S0081 1
PFMF
S00603
NEGCOUNTFAILED
S00808
PFOF
S00602
CH
S00601 BACKUPTO
S00600 CURRENTCHPTR
S00599 FORMPTR
S00598 MARKPTR
S00597 N
S00596 NPTR
S00595 GCPTR
S00593 PFGC
S00590 11000000
S00583 CURRENTBLOCK
S00582 CURRENTBLOCKPTR
S00581 CH
S00579 CHA
S00578 PUTCHASS
S00577 MOREFILL
S00576 ARGNUMBER
S00574 PFSS
S00566 CH
S00564 PFAS
S00557 PFNS
S00544 NEXTSTART
S00533 MATCHHERE
S00532 RESTARTPTR
S00531 CHB
S00530 CHA
S00528 SSMATCH
S00525 N
S00523 NUMBEROFARGS
S00520 HALFBYTE
S00519 HEXTOCH
S00518 57
S00517 37
S00515 47
S00513 '9'
S00511 CH
S00510 CHTOHEX
S00503 NEGATIVE
S00502 CH
S00501 N
S00499 BLOCKPTR
S00498 STRINGTOBINARY
S00495
S00491 '0'
S00487 NEGATIVE
S00486 K
S00485 I
S00484 D
S00482 N
S00481 BINARYTOSTRING
S00474 CH
S00473 BLOCK
S00472 BLOCKPTR
S00470 PROCESSBEGINFUNCTION
S00460 CH
S00459 LASTDELIMWASLEFT
S00458 DELIMLEVEL
S00456 PROCESSQUOTEDSTRING
S00452 BLOCK
S00451 BLOCKPTR
S00449 CH
S00448 NSADDCH
S00446 'NS STACK OVERFLOW S'
S00443 FLAGS
S00442 STARTNEXTARGUMENT
S00435 NEXT
S00434 OLDBLOCKPTR
S00433 CH
S00431 MOVEPTRFLAG
S00430 ASNEXTCH
S00428 ASFREEBLOCK
S00421 I
S00420 CLIM
S00417 ASNSINIT
S00411 74
S00409 ' T N I: S'
Number 24 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
174
Page 27
S00407 IB
S00405 CH
S00403 PROCESSCONBREAK
S00401 TURNTRACEOFF
S00333 TURNTRACESN
S00394 TRACEPRINT
S00392 NEXTNS
S00391 THIS
S00389 THISNS
S00386 60
S00385 7D
S00384 '.'
S00383 7C
S00382 73
S00381 70
S00380 7B
S00379 IM
S00376 STREINIT
S00374 STVALUEPTR
S00373 STADDVALUE
S00371 NAMEPTR
S00370 STCREATE
S00368 STDELETE
S00363 11111
S00360 CH
S00359 HASH
S00357 NAMEPTR
S00356 STFIND
S00352 STINIT
S00331 STPREVIOUS
S00350 STPREVIOUSPTR
S00349 STENTRY
S00348 STENTRYPTR
S00347 HASH INDEX
S00346 HASHTABLE
S00342 5000
S00330 MATCHEND
S00329 CHA
S00328 I
S00327 COUNTMAX
S00326 COUNT
S00325 RESTARTPTR
S00323 ENDMESSAGEPTR
S00322 RECEIVESTRING
S00318 CH
S00316 BLOCKPTR
S00315 SENDSTRING
S00311 CLEAROCTOOUTPUT
S00305 CH
S00303 BLOCKPTR
S00302 PRINTSTRING
S00297 CH
S00295 BLOCKPTR
S00294 NULLTEST
S00287 NEXTB
S00283 NEXTA
S00282 CHB
S00281 CHA
S00279 PTB
S00278 PTA
S00277 STRINGEQUALITY
S00273 CH
S00271 SINKPTR
S00270 SOURCEPTR
S00269 COPYVALUE
S00266 NEWCHAIN
S00265 CH
S00264 CURRENTBLOCK
S00262 CHA
S00261 1NITIALBLOCKPTR
S00260 PUTCHA
S00257 NEWCHAIN
S00256 CH
S00255 CURRENTBLOCK
S00254 CHPTR
S00253 CURRENTBLOCKPTR
S00251 INITIALBLOCKPTR
S00250 GETCHB
S00247 NEWCHAIN
S00246 CH
S00245 CURRENTBLOCK
S00244 CURRENTBLOCKPTR
S00242 INITIALBLOCKPTR
S00241 GETCHA
S00239 OF
S00233 BLOCKC
S00232 CHPTR
S00231 BLOCK
S00229 BLOCKPTR
S00228 CH
Page 28 Dr. Dobb's Journal
S00227 APPENDCH
S00222 OFFFO
S00221 NEXTPTR
S00220 BLOCK
SO0218 BLOCKPTR
S00217 FREECHAIN
S00213 16
S00211 BLKPTR
S00209 MAXADDRESS
S00208 MINADDRESS
S00207 FSINIT
S00206 8181
S00201 'FREE STORAGE IS EMPTY
S00199 FIRSTEMPTY
S00198 GOTC
S00197 GOT
S00196 GOTPTR
S00195 FSFIRST
S00193 FSGET
S00192 FREETHIS
S00190 FREETHISPTR
S00189 FSFREE
S00188 NOEXVALUE
S00187 DEADSTART
S00186 NULLSTRINGPTR
S00185 FPTR
S00184 SPTR
S00183 VALUECH
S00182 VALUEPTR
S00181 ARGPTR
S00180 NAMEPTR
S00179 TRACEFLAG
S00178 SSCHA
S00177 SSCHCPTR
S00176 SSCHBPTR
S00175 SSCHAPTR
S00174 ASCH
S00173 ASCHPTR
S00172 ASBLOCK
S00171 ASBLOCKPTR
S00170 NSACT IVEFLAG
S00169 NSARGBREAK
S00168 NSCH
S00167 NSCHPTR
S00166 NSSAVEINDEX
S00165 NSSTACKINDEX
S00164 11
S00163 NSSTACK
S00I62 PUTCHACURRENTBLOCKPTR
S00161 PUTCHACHPTR
S00160 GETCHACHPTR
S00159 FIRSTPUTAFLAG
S00158 FIRSTGETBFLAG
S00157 FIRSTGETAFLAG
S00156 FSFIRSTPTR
S00155 7F
S00151 65000
S00149 I
S00147 RECEIVECH
S00141 CH
S00140 SENDCH
S00137 OCTOSTATUS
S00136 OCTOCHANNELA
S00135 135
S00131 I
S00129 N
S00128 WAITTENTH
S00125 I
S00123 N
S00122 WAITMS
S00121 20
S00119 7A
S00118 61
S00116 CH
S00115 UPPERCASE
S00114 14
S00112 7
S00108 SELECTOR IVE
S00107 9
S00105 MESSPTR
S00104 PRINTMESS
S00103 11
S00101 CONBREAK
S00099 READCH
S00095 CH
S00094 DISPLAYCH
S00090 CH
S00089 PRINTCH
S00088 OA
S00087 OD
Computer Calisthenics & Orthodontia, Box E,
S00086 2
S00084 CRLF
S00082 A
S00081 F
S00080 M0N2
S00079 5
S00077 A
S00076 F
S00075 MON 1
S00074 FBASE
S00073 6
S00072 FBASEA
S00071 I TEMP
S00070 DUMMY
S000S9 TEMPPTR
S00068 CURRENTDRIVE
S00067 PREVIOUSDRIVE
S00066 DEFAULTDRIVE
S00065 PRELOADED
S00064 7E
S00063 METACHAR
S00062 04
S00061 OCTOEOM
S00060 TBUFFINDEX
S00059 TBUFF
S00058 80
S00057 TBUFFPTR
S00056 TFCB
S00055 5C
S00054 TFCBPTR
S00053 120
S00052 OCTOTIMEOUT
S00051 1
S00050 CONBUF
S00049 CON IN
S00048 80
S00047 CONCOLUMN
S00046 CONWIDTH
S00045 OFF
S00044 CPMPRINTFLAG
S00043 62
S00042 ATCB
S00040 6F
S00039 72
S00038 ATRO
S00036 6E
S00035 69
S00034 AT IN
S00032 81
S00031 63
S00030 67
S00029 40
S00028 0
S00027 ATGC
S00025 START
S00024 100
S00022 DEC
S00021 DOUBLE
S00020 MOVE
S00019 LAST
S00018 LENGTH
S00017 OUTPUT
S00016 INPUT
S00015 LOW
S00014 HIGH
S00013 TIME
S00012 SCR
S00011 SCL
S00010 SHR
S00009 SHL
S00008 ROR
S00007 ROL
S00006 STACKPTR
S00005 MEMORY
S00004 PARITY
S00003 SIGN
S00002 ZERO
S00001 CARRY
8080 PLM2 VERS 3.0
Menlo Park, CA 94025 Number 24
175
1=0000030
100=0004460
151=0004760
161=0005420
167=0005720
175=000617Q
186=0006620
194 = 00071 IQ
200=0007560
212=0010150
221=001126Q
227=0012230
253=0012610
259=0013040
268=001375Q
340=0014440
358=0015420
366=0016200
372=0017300
383=0020460
392 = 00211 IQ
398=0021670
411=0022360
417=0023010
424=0023660
441=0024270
447=0025240
463=0025650
476=0026500
487=0027200
498=0030010
508=0030620
524=0031650
537=0032440
546=0033340
560=0034530
572=0035030
582=0035670
598=0036240
604=0037430
610=0040050
617=0040550
624=004115Q
630=0042660
662=0043640
675=0044300
681=0045120
692=0046200
702=0046750
708=0050220
718 = 00511 IQ
730=0051730
737=0052520
748=0053530
762=0054210
768=0054610
775=0055030
785=0055410
791=0056600
797=0057210
813=0057550
819=0060430
827=0061210
835=0061620
850=0062360
859=0062740
865=0063430
876=0064640
889=0065560
895=0066530
906=0067230
912=0067740
918=0070220
929=0070750
935=0071340
947=0071740
958=0072640
965=0074340
971=0075260
982=0076150
988=0077500
996=0100140
1004=0100570
1027=0101320
1035=0102120
1044=010256Q
1052=0103320
1061=010440Q
1067=0104710
1084=0105610
1095=010626Q
1 102 = 0107130
1 108 = 011006Q
18=0004030
144=0004560
154=0005070
162=0005500
168=0005730
177=0006300
187=0006650
195=0007200
201=0007570
214=0010230
222=001136Q
244=0012330
254=0012660
263=0013140
269=0014020
353=001453Q
359=001553Q
367=0016340
373=0017430
384=0020510
393=0021270
402=0021770
412=0022470
419 = 00231 IQ
431=0023740
442=0024470
453=0025320
464=0026050
481=0026600
488=0027350
503=0030060
512=0030740
525=0031670
541=0032510
551=0033420
561=0034560
573=0035270
583=0036020
599=0036400
605=0037460
611=0040200
618=0040620
625=0041220
631=0043000
663=0043650
676=0044340
682=0045400
693=0046360
703=0047030
709=0050270
719=005116Q
731=0052040
738=0052750
749=0053550
763=0054330
769=0054640
777 = 00551 IQ
786=0056010
792=0056630
798=0057220
814=0057640
820=0060600
828=0061300
836=0062010
851=0062410
860 = 00631 7Q
870=0063470
877=0065230
890=0065770
896=0066640
907=0067300
913=0070040
919=0070230
930=0071060
936=0071410
953=0072000
959=0072700
966=0074550
972=0075440
983=0076210
989=0077520
997=0100230
1005=0100630
1028=0101370
1036=0102220
1045=0102620
1055=0103460
1062=0104430
1079=0104740
1085=0105700
1096=0106410
1 103 = 0107100
1109=0110320
96=0004060
145=0004610
155=0005200
163=0005600
171=0005770
178=0006310
188=0006660
196=0007240
205=0007630
215=001072Q
223=001150Q
245=0012370
255=0012710
264=001333Q
270=001405Q
354=001461Q
361=001556Q
368=001650Q
374=0017440
385=0020520
394=0021320
407=0022040
413=0022570
420=0023260
436=0024040
443=0024630
458=0025420
465=002613Q
483=0026620
489=0027400
504=0030340
517=0030770
529*003174Q
542=0032620
556=0033470
562=0034650
574=0035300
584=0036050
600=0036720
606=0037540
612=0040220
619=0040670
626=0042000
632=0043130
667=0043730
677=0044400
683=0045520
694=0046440
704=0047200
713=0050350
724=0051210
732=0052150
739=0053170
750=0053700
764=0054360
770=0054650
778=0055120
787=0056120
793=0056740
807=0057250
815=0057710
821=0060640
829=0061330
837*00621 IQ
852=0062560
861=0063250
872=0063540
878=0065260
891=0066040
897=0067100
908=0067410
914=0070030
925=0070300
931=00711 IQ
937*0071550
954*0072030
960=0072740
967=0074660
973=0075710
984=0076570
990=0077550
998=0100350
1011=0100700
1030=010150Q
1037=010225Q
1046*0102760
1056*0103650
1063=0104510
1080=0105070
1086=0106040
1097=0106550
1104=0107150
1 110 = 0110420
97=0004200
146=0004620
157=0005250
164=0005650
172=0006010
181=0006420
191=0006720
197=0007310
206=0007660
216=0010730
224=0011650
246=0012430
256=0012760
265=0013420
333=0014130
355=001522Q
363=001570Q
369=001664Q
379=001756Q
388=0020600
395=0021500
408=0022160
414=0022610
421=0023310
438=0024060
444=0024770
460=0025440
466=0026310
484=0026760
490=0027640
505=0030430
518=0031310
530=0032200
543=0032670
557=0034220
564=0034700
578=0035360
585=0036060
601=0037060
607=0037570
614=0040370
620=0040750
627=0042270
633=0043200
672=0043760
678=0044730
684=0045770
695=0046630
705=0047420
715=0050450
725=0051360
733=0052310
740=0053260
751=0053760
765=0054440
772=0054720
779=0055130
788=0056200
794=0056770
808=0057330
816=0060070
822=0060740
830=0061370
838=006214Q
853=0062640
862=0063320
873=0064050
879=0065270
892=0066120
898=0067120
909=0067510
915=0070140
926=0070410
932=0071160
938=0071600
955=0072220
962=0073060
968=0075100
974=0076000
985=0076650
991=0077770
999=0100410
1012=010115Q
1031=0101610
1038=0102320
1047=0103160
1058=0104010
1064=0104560
1 081=010534Q
1087=0106170
1098=0106660
1 105 = 0107370
1 1 11=011045Q
98=0004260
149=0004720
158=0005260
165=0005720
173=0006070
182=0006430
192=0006770
198=0007420
207=0010030
219=001101Q
225=0012020
250=0012470
257=001301Q
266=0013550
338=001427Q
356=0015320
364=0015760
370=001700Q
381=0017700
390=0020720
396=0021630
409=0022240
415=0022720
422=0023550
439=0024200
445=0025150
461=0025560
467=0026330
485=0027060
491=0027660
506=0030560
519=0031330
531=0032340
544=0033200
558=0034340
565=0034710
579=0035410
591=0036140
602=003715Q
608=0037720
615=0040420
622=0041000
628=0042360
634=0043220
673=0044030
679=0044750
685=0046020
696=0046640
706=0047650
716=0050530
728=005143Q
734=0052420
741=0053360
754=0054030
766=0054450
773=0054740
783=0055210
789=0056240
795=005710Q
811=0057440
817=0060310
625=0060760
831=0061400
844=0062200
855=0062700
863=0063340
874=0064430
884=0065330
893=0066220
899=0067130
910=0067550
916 = 00701 IQ
927=0070460
933=0071230
939=007165Q
956=0072260
963=0073110
969=007513Q
975=0076010
986=0076700
992=0100050
1002=0100450
1013=0101220
1032=0101720
1039=0102330
1048=0103260
1059=0104100
1065=0104610
1082=0105510
1088=0106220
1099=0106750
1 106 = 0107620
1 112 = 011050Q
99=0004400
150=0004750
160=0005320
166=0005750
174=0006140
185=0006510
193=0007060
199=0007450
208=0010070
220=001107Q
226=0012220
252=0012520
258=0013030
267=001363Q
339=001443Q
357=001534Q
365=001604Q
371=0017140
382=0020370
391=002114Q
397=002166Q
410=0022320
416=0022740
423=0023570
440=0024250
446=002517Q
462=0025630
468=0026400
486=0027100
492=0027670
507=0030610
523=003144Q
532=0032360
545=0033310
559=0034440
571=0035000
581=0035450
597=0036170
603=0037300
609=0040010
616=0040520
623=004113Q
629=0042510
661=0043270
674=0044250
680=0045100
691=0046120
700=0046720
707=0050120
717=0050630
729=005162Q
736=0052470
742=0053370
755=0054160
767=0054540
774=0054750
784=0055340
790=0056440
796=005716Q
812=0057470
818=0060400
826=006103Q
634=006154Q
849=0062230
656=0062710
664=0063360
675=0064450
688=0065430
894=0066370
905=0067200
911=0067660
917=0070170
928=0070700
934=0071260
940=0071660
957=0072370
964=0073150
970=0075210
977=0076070
987=0077040
995 = 01001 IQ
1003=0100500
1014=0101270
1034=0102010
1043=0102470
1049=0103310
1060=0104240
1066=0104700
1083=0105600
1089=0106230
1 101 =0107000
1 107 = 011002Q
1113=0110510
Number 24
176
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
1123=011054Q
1133=011 141Q
1139=011203Q
1145=011266Q
1151=011401Q
1168=011470Q
1179=0116000
1186=011667Q
1192=011733Q
1199=0120030
1205=0120550
1212=0121350
1218=0122620
1230=012326Q
1236=0124230
1242=0125350
1248=0126240
1255=012707Q
1264=013002Q
1276=0130500
1282=0131270
1292=0132330
1300=0133100
1314=0133720
1320=0134640
1326=0136130
1333=0137020
1347=0137570
1355=0140140
1369=0140640
1376=0141420
1383=0142150
1389=0142760
1396=0143410
1403=014412Q
1415=0144550
1421=014560Q
1431=0146640
1439=0147300
1450=015004Q
1457=0150640
1463=0151430
1479 = 01521 IQ
1490=0152730
1502=015466Q
1513=015566Q
1526=0156210
1532=015731Q
1538=016003Q
1556=0160730
1562=016156Q
1572=0162300
1586=0163010
1594=0164330
1600=0165000
1608=0165250
1617=0166520
1625=0167300
1633=016760Q
1641=017030Q
1649=0171000
1660=0171550
1667=0172310
1674=0173240
1680=0174340
1691=0175050
1697=0176040
1703=0177140
1714=0177440
1777=0200240
1784=0201250
1792=0202070
1799=0202770
1805=0204230
1811=0204720
1817=0205360
1823=0206020
1829=0206460
1835=0207120
1841=0207600
1847=021173Q
1857 = 02131 IQ
1864=0213700
1872=0214400
1878=0215340
1884=0216150
1892=021665Q
1905=021747Q
1912=0220210
1919=0220640
1925=0222240
1931=0223300
1937=0223750
1943=0224250
1952=0224670
1958=0225260
1124=0110600
1134=011143Q
1140=0112100
1146=011314Q
1152=0114140
1169=011472Q
1180=0116200
1187=011672Q
1193=0117510
1200=0120110
1206=012066Q
1213=0121500
1225=0122650
1231=012354Q
1237=0124300
1243=0125400
1249=0126330
1256=0127160
1265=013007Q
1277=0130630
1283=0131300
1293=0132420
1301=0133240
1315=0133770
1321=0135140
1327=0136210
1337=0137050
1348=0137720
1356=0140200
1370=014110Q
1378=0141450
1384=0142200
1390=0143010
1397=0143470
1410=0144150
1416=0144610
1426=0145630
1432=0147060
1445=0147360
1451=0150070
1458=0150700
1464=0151440
1480=0152270
1491=0152770
1503=0154770
1514=0155670
1527=0156260
1533=0157400
1539=0160040
1557=0161030
1563=0161570
1573=0162350
1589=0163060
1595=0164400
1601=016502Q
1610=0165350
1618=016653Q
1626=0167330
1634=0167630
1642=017036Q
1650=0171070
1661=0171710
1668=017253Q
1675=0173520
1685=017437Q
1692=0175160
1698=0176100
1704=0177230
1715=0177450
1778=0200320
1785=020127Q
1793=0202250
1800=0203230
1806=0204340
1812=0205000
1818=0205440
1824=0206100
1830=0206540
1836=0207200
1842=0207660
1848=0212070
1858=021325Q
1865=0213730
1873=0214610
1879=021540Q
1885=0216220
1900=0216730
1906=0217730
1913=0220310
1920=022107Q
1926=0222270
1932=0223330
1938=0224000
1945=0224300
1953=0225000
1959=0225310
1129=011064Q
1135=011144Q
1141=011226Q
1147*011333Q
1153*0114170
1175=0115020
1181*0116230
1188*011700Q
1194*0117560
1201*0120150
1207=0120730
1214*0121630
1226*0122730
1232*0123710
1238*0124340
1244=0125520
1250=0126470
1257=0127420
1272*0130120
1278*0130640
1288*0131330
1296=0132450
1302=0133470
1316*0134070
1322*0135230
1328*0136470
1338*0137130
1349=0137670
1357-014025Q
1371-014115Q
1379*0141530
1385-0142270
1392=0143060
1398=014352Q
1411*0144230
1417*0144700
1427*0145760
1433*01471 IQ
1446=0147510
1452*0150140
1459=0151010
1468=0151470
1481=0152510
1492=0153340
1504*015510Q
1518*0155720
1528=015650Q
1534=015755Q
1546=016007Q
1558=0161170
1566=0161620
1574=0162500
1590=0163440
1596=0164510
1602=0165100
1611=0165610
1621*0166560
1627=0167410
1635=0170130
1643=0170600
1651=0171100
1662=0171750
1669=0172670
1676=0174000
1686=017456Q
1693=0175410
1699=0176270
1705=0177260
1730=0177500
1779=0200350
1787=0201430
1794=0202350
1801=0203530
1807=0204420
1813=0205060
1819=0205520
1825=0206160
1831*0206620
1837=0207260
1843=0207740
1853=0212130
1859=0213410
1866*0214310
1874*0214720
1 880 = 021551Q
1886=0216440
1901=021706Q
1907=021776Q
1915=0220330
1921=022174Q
1927=0222520
1933=0223540
1939=0224100
1948=0224350
1954=0225030
1130=0110740
1136=011147Q
1142=011237Q
1148=011343Q
1154=011420Q
1176=0115070
1182=0116310
1189=0117030
1195=0117650
1202=0120250
1208=0120750
1215=0122250
1227=0122760
1233=0124020
1239=0124430
1245=0125550
1251=0126630
1258=0127430
1273=0130200
1279=0131070
1289=0131620
1297=0132530
1303=0133620
1317=0134330
1323=0135400
1329=0136730
1339=0137220
1350=0140050
1366=0140300
1372=014116Q
1380=0141600
1386=0142320
1393 = 01431 IQ
1399=0143710
1412=0144260
1418=0145210
1428=0145730
1434=0147120
1447=014754Q
1453=0150360
1460=0151140
1469=0151620
1482=0152560
1493=0153350
1505=0155110
1519=0156020
1529=0156610
1535=0157620
1547=0160130
1559=0161240
1567=0162160
1575=0162610
1591=0163520
1597=0164540
1603=016513Q
1612=0166070
1622=0166620
1628=0167420
1636=0170160
1644=0170630
1657=017113Q
1663=0172100
1670 = 01731 IQ
1677=0174030
1687=0174670
1694=0175460
1700=0176470
1706=0177270
1731=0177560
1781=0200420
1788=0201510
1796=0202320
1802=0203760
1808=0204500
1814=0205140
1820=0205600
1826=0206240
1832=0206700
1838=0207340
1844=0210020
1854=0212200
1860=0213530
1867=0214340
1875=0214750
1881=0215650
1887=0216500
1902=0217230
1908=0217770
1916=0220370
1922=0222020
1928=0222770
1934=0223570
1940=0224120
1949=0224460
1955=0225140
1131=011101Q
1137=011161Q
1143=0112530
1149=011362Q
1166=011423Q
1177=0115210
1184=0116370
1190=0117140
1196=011774Q
1203=0120330
1209=0121240
1216=0122350
1228=0123070
1234=0124100
1240=0124570
1246=0125710
1252=0126660
1262=0127460
1274=0130230
1280=0131230
1290=0132170
1298=0132640
1305=0133630
1318=0134410
1324=0135520
1330=0136760
1340=0137340
1351=0140100
1367=0140410
1374=0141310
1381=0141700
1387=0142370
1394=0143210
1400=0144060
1413=0144340
1419=0145540
1429=0146070
1437=014715Q
1448=0147650
1454=0150420
1461=0151170
1470=0152000
1483=0152670
1500=0153450
1511=0155140
1520=0156030
1530=0157010
1536=0157730
1548=0160570
1560=0161340
1568=0162170
1576=0162720
1592=0164170
1598=0164570
1604=0165160
1613=0166130
1623=0166750
1631=0167450
1637=0170240
1645=0170710
1658=0171250
1664=0172230
1671=0173140
1678=0174110
1688=0174760
1695=0175720
1701=0176530
1712=0177340
1775=0177620
1782=0200660
1789=0201570
1797=0202560
1803=0204040
1809=0204560
1815=0205220
1821=0205660
1827=0206320
1833=0206760
1839=0207420
1845=0210230
1855=0212430
1861=0213550
1870=0214310
1876=0215050
1882=0216000
1888=0216530
1903=0217300
1910=0220100
1917=0220460
1923=0222160
1929=0223130
1935=0223640
1941=0224150
1950=0224510
1956=0225170
1132=011115Q
1138*011165Q
1144=011262Q
1150=0113760
1167=011445Q
1178=0115460
1185=0116520
1191=0117250
1197=0117750
1204=0120410
1210=0121270
1217=0122610
1229=0123200
1235=0124150
1241=012501Q
1247=0125770
1254=0126740
1263=0127600
1275=0130360
1281=0131240
1291=0132220
1299=0133020
1309=0133670
1319=0134460
1325=0135710
1332=0137010
1346=0137410
1352 = 01401 10
1368=0140430
1375=0141350
1382=0142060
1388=0142530
1395=0143250
1401=01441 IQ
1414=0144440
1420=0145570
1430=0146370
1438=0147270
1449=014776Q
1455=0150530
1462=0151300
1471=0152010
1484=0152700
1 501=0153630
1512=0155200
1525=0156060
1531=0157120
1537=0160000
1 549 = 0160600
1561=0161450
1571=0162220
1577=016273Q
1593=0164250
1599=016462Q
1605=016517Q
1616=0166230
1624=016700Q
1632=0167510
1638=0170250
1646=0170720
1659=0171350
1665=0172240
1672=0173170
1679=0174330
1690=0175010
1696=0175750
1702=0176740
1713=0177410
1776=0177730
1783=0201200
1791=0201650
1798=0202640
1804=0204070
1610=0204640
1816=0205300
1822=0205740
1828=0206400
1834=0207040
1840=0207500
1846=0210340
1856=0213010
1863=0213630
1871=0214360
1877=0215200
1883=0216100
1889=0216640
1904=0217340
1911=0220140
1918=0220560
1924=0222210
1930=0223160
1936=0223740
1942=0224200
1951=0224620
1957=0225220
Number 24
Page 30
S00001 22744Q S00002 22744Q S00003 22744Q S00004 22744Q
S00005 25000Q S00006 22744Q S00023 22744Q S00044 22744Q
S00046 22745Q S00047 22746Q S00049 22747Q S00030 22750Q
S00052 23072Q S00054 23074Q S00057 23076Q S00060 23101Q
S00061 23102Q S00063 23103Q S00065 23104Q S00066 23105Q
S00067 23106Q S00068 23107Q S00069 23110Q S00070 23112Q
S00071 23113Q S00072 23114Q S00076 23117Q S00077 23120Q
S00081 23123Q S00082 23124Q S00090 23126Q S00095 23127Q
S00105 23130Q S00116 23133Q S00123 23134Q S00125 23136Q
S00129 23140Q S00131 23142Q S00136 23144Q S00141 23145Q
S00149 23146Q S00156 23150Q S00137 23153Q S00158 23154Q
S00159 23155Q S00160 23156Q S00161 23160Q S00162 23162Q
S00163 23164Q S00165 24162Q S00166 24163Q S00167 24164Q
S00169 24166Q S00170 24167Q S00171 24170Q S00173 24172Q
S00175 24174Q S00176 24176Q S00177 24200Q S00179 24203Q
S00180 24204Q S00181 24206Q S00182 2421OQ S00184 24212Q
S00185 24214Q S00186 24216Q S00187 24220Q S00188 24221Q
S00190 24222Q S00196 24224Q S00199 24227Q S00208 24230Q
S00209 24232Q S00211 24234Q S00218 24236Q S00221 24240Q
S00228 24243Q S00229 24244Q S00232 24246Q S00242 24250Q
S00244 24252Q S00247 24255Q S00251 24256Q S00253 24260Q
S00254 24262Q S00257 24265Q S00261 24266Q S00262 24270Q
S00266 24271Q S00270 24272Q S00271 24274Q S00273 24277Q
S00278 24300Q S00279 24302Q S00281 24304Q S00282 24305Q
S00295 24306Q S00297 2431 IQ S00303 24312Q S00305 24315Q
S00316 24316Q S00318 24321Q S00323 24322Q S00325 24324Q
S00326 24326Q S00327 24330Q S00328 24332Q S00329 24335Q
S00346 24336Q S00347 24437Q S00348 24440Q S00350 24442Q
S00357 24444Q S00359 24446Q S00360 24447Q S00371 24450Q
S00374 24452Q S00391 24454Q S00405 24456Q S00421 24457Q
S00431 24460Q S00433 24461Q S00434 24462Q S00443 24464Q
S00449 24465Q S00451 24466Q S00458 24471Q S00459 24472Q
S00460 24473Q S00472 24474Q S00474 24477Q S00482 24500Q
S00484 24503Q S00485 2451 IQ S00486 24512Q S00487 24513Q
S00499 24514Q S00501 24516Q S00502 24521Q S00503 24522Q
S00511 24523Q S00520 24524Q S00525 24525Q S00530 24526Q
S00531 24527Q S00532 24530Q S00566 24532Q S00576 24533Q
S00577 24534Q S00579 24535Q S00582 24536Q S00595 24540Q
S00596 24542Q S00597 24544Q S00598 24546Q S00599 24550Q
S00600 24552Q S00601 24554Q S00602 24556Q S00603 24557Q
S00610 24560Q S00624 24562Q S00625 24565Q S00642 24566Q
S00643 24570Q S00644 24572Q S00660 24574Q S00662 24575Q
S00663 24576Q S00664 24577Q S00665 24600Q S00680 24601Q
S00688 24602Q S00689 24603Q S00690 24604Q S00715 24605Q
S00716 24606Q S00722 24607Q S00730 2461OQ S00742 24612Q
S00749 24614Q S00756 24616Q S00759 24621Q S00777 24622Q
S00787 24624Q S00789 24627Q S00790 24630Q S00791 24631Q
S00803 24632Q S00823 24635Q S00824 24636Q S00825 24637Q
S00840 24640Q S00851 24642Q S00854 24644Q S00856 24647Q
S00857 24650Q S00858 24651Q S00860 24652Q S00862 24655Q
S00863 24656Q S00973 24777Q SOI 004 22743Q SOI 005 22742Q
SOI 006 22740Q SOI 008 22736Q SOI 010 22734Q SOI Oil 22732Q
SOI 013 22730Q S01014 22726Q S01015 22724Q S01016 22722Q
SOI 017 22720Q SOI 018 22716Q SOI 019 22714Q SOI 021 22712Q
STACK SIZE = 18
BYTES
000400Q
LX I SP
22712Q
JMP
22021 Q
000406Q
000Q
OOOQ 100Q
147Q 143C
1 201Q i
OOOQ OOOQ
OOOQ OOOQ
000420Q
OOOQ
OOOQ 1OOQ
151Q 156C
1 201 Q
000426Q
OOOQ
OOOQ 1OOQ
162Q 157C
1 201Q i
OOOQ OOOQ
OOOQ OOOQ
000440Q
OOOQ
OOOQ 1OOQ
143Q 142C
1 201 Q
000446Q
LX I H
23117Q
MOV MC
INR L
MOV ME
000454Q
I NX H
MOV MD
JMP
5Q
RET
000462Q
LX! H
23123Q
MOV MC
INR L
MOV ME
000470Q
I NX H
MOV MD
JMP
3Q
RET
000476Q
MOV Cl
2Q
MOV El
15Q
MOV D1
OQ
CALL
446Q
000507Q
MOV Cl
2Q
MOV El
1 2Q
MOV Dl
OQ
CALL
446Q
000520Q
LX I H
22746Q
MOV MI
OQ
RET
LXI H
23126Q
000531Q
MOV MC
MOV Cl
2Q
MOV EM
MOV Di
OQ
000537Q
CALL
446Q
LX I H
23126Q
MOV AM
sub r
1 5Q
000550Q
JNZ
5600
DCR H
MOV LI
346Q
MOV MI
OQ
000560Q
LX I H
22746Q
INR M
MOV AM
DCR L
000566Q
SUB M
CZ
476Q
RET
LXI H
23127Q
000576Q
MOV MC
IN
IQ
RRC
RRC
000603Q
RRC
JC
577Q
LXI H
23127Q
MOV AM
000613Q
CMA
OUT
OQ
RET
MOV Cl
IQ
000621Q
MOV El
OQ
MOV DI
OQ
CALL
462Q
RET
000631Q
MOV Cl
13Q
MOV El
OQ
MOV Dl
OQ
CALL
462Q
000642Q
RET
LX I H
23130Q
MOV MC
1 NX H
000650Q
MOV MB
MOV Cl
1 IQ
DCR L
MOV EM
000655Q
I NR L
MOV DM
CALL
446Q
CALL
476Q
000665Q
RET
LHLD
23074Q
MOV AM
SUB 1
OQ
000674Q
JNZ
71 IQ
LX I H
23105Q
MOV CM
MOV LI
107Q
000705Q
MOV MC
JMP
731Q
LHLD
23074Q
MOV AM
000715Q
ANA I
7Q
DCR A
LXI H
23107Q
MOV MA
000724Q
LHLD
23074Q
MOV MI
OQ
LXI H
23106Q
MOV AM
000735Q
I NR L
SUB M
JZ
756Q
MOV CM
000743Q
DCR L
MOV MC
MOV Cl
16Q
INR L
000750Q
MOV EM
MOV DI
OQ
CALL
446Q
RET
000757Q
LX 1 H
23133Q
MOV MC
MOV AM
SUB I
1 41Q
000766Q
SBC A
MOV CA
MOV AI
1 72Q
SUB M
000773Q
SBC A
ORA C
RRC
JNC
1003Q
001001Q
MOV AM
RET
MOV AM
SUB 1
40Q
001006Q
RET
LX I H
23134Q
MOV MC
I NX H
Number 24 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 31
178
001014Q
MOV
MB
INR
L
MOV
Ml
OQ
I NX
H
001021Q
MOV
MI
00
LX I
H
23136Q
MOV
AM
I NR
L
001030Q
MOV
BM
MOV
LI
134Q
SUB
M
I NR
L
001035Q
MOV
CA
MOV
AB
SBC
M
JNC
1072Q
001043Q
MOV
AI
7Q
MOV
B1
140
MOV
CB
DCR
C
001051Q
JNZ
10500
DCR
A
JNZ
1047Q
LHLD
231360
001063Q
I NX
H
SHLD
23136Q
JMP
1023Q
RET
001073Q
LX I
H
23140Q
MOV
MC
I NX
H
MOV
MB
001101Q
1 NR
L
MOV
MI
10
I NX
H
MOV
MI
OQ
001107Q
LX I
H
231400
MOV
AM
INR
L
MOV
BM
001115Q
I NR
L
SUB
M
INR
L
MOV
CA
001121Q
MOV
AB
SBC
M
JC
1222Q
CALL
631 Q
001131Q
RRC
RC
MOV
AI
377Q
MOV
B1
14Q
001137Q
MOV
CB
DCR
C
JNZ
1 1 40Q
DCR
A
001145Q
JNZ
11370
MOV
AI
377Q
MOV
B1
14Q
MOV
CB
001155Q
DCR
C
JNZ
1 155Q
DCR
A
JNZ
1154Q
001165Q
MOV
A I
207Q
MOV
BI
14Q
MOV
CB
DCR
C
001173Q
JNZ
1 1 72Q
DCR
A
JNZ
11710
LX I
H
23142Q
0012050
MOV
CM
1 NR
L
MOV
BM
LX I
H
IQ
001213Q
DAD
B
SHLD
231420
JMP
1 1 07Q
RET
001223Q
LX I
H
23144Q
MOV
AM
RRC
JNC
1237Q
001233Q
IN
5Q
CMA
RET
I N
7Q
001241Q
CMA
RET
LX I
H
231450
MOV
MC
001247Q
CALL
1223Q
RRC
RRC
CMA
001235Q
RRC
JC
1247Q
MOV
AM
RRC
0012630
JNC
1276Q
INR
L
MOV
AM
CMA
001271Q
OUT
4Q
JMP
1303Q
INR
L
MOV
AM
001300Q
CMA
OUT
6Q
RET
LX I
H
23146Q
001307Q
MOV
Ml
00
I NX
H
MOV
Ml
OQ
MOV
A I
3500
0013160
MOV
BI
375Q
LX 1
H
23146Q
SUB
M
INR
L
001325Q
MOV
CA
MOV
AB
SBC
M
JC
1402Q
001333Q
CALL
1223Q
RRC
JNC
1363Q
MOV
AM
001343Q
RRC
JNC
1 3350
IN
4Q
CMA
001352Q
ANA
I
1770
RET
IN
6Q
CMA
001360Q
ANA
I
1 77Q
RET
MOV
LI
1 460
MOV
CM
001366Q
I NR
L
MOV
BM
LX I
H
IQ
DAD
B
001374Q
SHLD
231460
JMP
1314Q
MOV
A I
377Q
RET
001405Q
LX I
H
24222Q
MOV
MC
I NX
H
MOV
MB
001413Q
LX I
H
23150Q
MOV
CM
INR
L
MOV
BM
001421Q
LHLD
242220
MOV
MC
I NX
H
MOV
MB
001427Q
LX I
H
24222Q
MOV
CM
INR
L
MOV
BM
001435Q
LX I
H
23150Q
MOV
MC
I NX
H
MOV
MB
001443Q
RET
LX I
H
23150Q
MOV
CM
INR
L
001451Q
MOV
BM
MOV
CB
MOV
AC
SUB
1
OQ
0014560
JNZ
15560
JMP
1314Q
001464Q
106Q
122Q 1 050
105Q
040Q 123Q
1 24Q 117Q
122Q 1 01Q
1070 105Q 0400
001502Q
1 23Q l
040Q 105Q
1 15Q
120Q 124Q
1 31Q 040Q
040Q 044Q
001514Q
LX 1
B
1464Q
CALL
643Q
LX I
H
24227Q
MOV
AM
001526Q
RRC
JNC
1542Q
MOV
MI
OQ
LX I
SP
22712Q
001537Q
JMP
403Q
MOV
Cl
OQ
MOV
El
00
MOV
DI
OQ
001550Q
CALL
446Q
JMP
1743Q
DCR
L
MOV
CM
001560Q
I NR
L
MOV
BM
LX I
H
24224Q
MOV
MC
001566Q
1 NX
H
MOV
MB
LHLD
23150Q
MOV
AM
001574Q
I NX
H
MOV
BM
LX 1
H
23150Q
MOV
MA
0016020
I NX
H
MOV
MB
LHLD
24224Q
MOV
Ml
OQ
00161 IQ
1 NX
H
MOV
Ml
OQ
DCX
H
1 NX
H
001616Q
1 NX
H
MOV
Ml
201Q
I NX
H
MOV
Ml
201Q
001624Q
LX I
B
4Q
LHLD
24224Q
DAD
B
MOV
MI
20 IQ
001635Q
I NX
H
MOV
MI
201Q
LX I
B
6Q
LHLD
24224Q
001646Q
DAD
B
MOV
MI
2010
I NX
H
MOV
MI
2010
001654Q
LX I
B
100
LHLD
24224Q
DAD
B
MOV
MI
201Q
0016650
I NX
H
MOV
MI
201 Q
LX I
B
12Q
LHLD
24224Q
0016760
DAD
B
MOV
MI
201Q
I NX
H
MOV
MI
201 Q
001704Q
LX I
B
14Q
LHLD
24224Q
DAD
B
MOV
MI
201 Q
001715Q
I NX
H
MOV
Ml
201Q
LX I
B
16Q
LHLD
24224Q
001726Q
DAD
B
MOV
MI
201 Q
I NX
H
MOV
Ml
201 Q
001734Q
LX I
H
242240
MOV
AM
INR
L
MOV
BM
001742Q
RET
RET
LX I
H
24230Q
MOV
MC
001750Q
I NX
H
MOV
MB
INR
L
MOV
ME
001754Q
I NX
H
MOV
MD
MOV
LI
230Q
MOV
CM
001761Q
I NR
L
MOV
BM
MOV
LI
234Q
MOV
MC
001766Q
I NX
H
MOV
MB
LX I
H
24232Q
MOV
AM
001774Q
I NR
L
MOV
BM
SUB
I
20Q
MOV
CA
002001Q
MOV
AB
SBC
I
OQ
MOV
BA
MOV
AC
002006Q
1 NR
L
SUB
M
INR
L
MOV
CA
002012Q
MOV
AB
SBC
M
JC
205 IQ
JMP
2037Q
002022Q
LX I
B
20Q
LHLD
24234Q
DAD
B
SHLD
24234Q
002034Q
JMP
1770Q
DCR
L
MOV
CM
INR
L
002042Q
MOV
BM
CALL
1403Q
JMP
20220
RET
002052Q
LX I
H
242360
MOV
MC
I NX
H
MOV
MB
002060Q
DCR
L
MOV
AM
INR
L
MOV
BM
002064Q
ANA
I
360Q
MOV
CA
MOV
AB
ANA
I
377Q
002072Q
DCR
L
MOV
MC
1 NX
H
MOV
MA
0020760
MOV
BA
MOV
AC
MOV
LI
2160
SUB
M
002103Q
INR
L
MOV
CA
MOV
AB
SBC
M
002107Q
ORA
C
RZ
LX 1
H
24236Q
MOV
CM
002115Q
INR
L
MOV
BM
MOV
CB
MOV
AC
002121Q
SUB
I
OQ
RZ
LHLD
24236Q
MOV
AM
002130Q
1 NX
H
MOV
BM
LX 1
H
24240Q
MOV
MA
002136Q
I NX
H
MOV
MB
MOV
LI
236Q
MOV
CM
002143Q
I NR
L
MOV
BM
CALL
1 405Q
LX I
H
24240Q
0021530
MOV
CM
INR
L
MOV
BM
MOV
LI
236Q
002160Q
MOV
MC
I NX
H
MOV
MB
JMP
21110
0021660
RET
LX I
H
24243Q
MOV
MC
INR
L
Page 32
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
179
Number 24
002174Q
MOV
ME
I NX H
MOV
MD
DCR L
002200Q
MOV
CM
INR L
MOV
BM
MOV CB
002204Q
MOV
AC
SUB 1
OQ
JNZ
221 6Q
XRA A
002213Q
MOV
B 1
00
RET
LHLD
24244Q
MOV AM
002222Q
I NX
H
MOV BM
MOV
CB
XRA A
002226Q
SUB
C
JNC
2247Q
DCX
H
MOV AM
002234Q
I NX
H
MOV BM
LX I
H
24244Q
MOV MA
002242Q
I NX
H
MOV MB
JMP
2216Q
LX I B
2Q
0022520
LHLD
24244Q
DAD B
SHLD
24246Q
LHLD
24246Q
002264Q
MOV
AM
SUB I
201Q
JZ
2301 Q
I NX H
002273Q
SHLD
24246Q
JMP
226 IQ
LX I
H
24243Q
MOV CM
002305Q
LHLD
24246Q
MOV MC
I NX
H
SHLD
24246Q
002315Q
XCHO
MOV AE
ANA
I
17Q
SUB I
OQ
002323Q
JNZ
2357Q
CALL
1 444Q
LHLD
24244Q
MOV MA
002335Q
I NX
H
MOV MB
LX I
H
24246Q
MOV MA
002343Q
I NX
H
MOV MB
LX I
B
2Q
LHLD
24246Q
002353Q
DAD
B
SHLD
24246Q
LX I
H
24246Q
MOV AM
002363Q
I NR
L
MOV BM
RET
LX I H
24250Q
002371Q
MOV
MC
I NX H
MOV
MB
LX I H
23153Q
002377Q
MOV
AM
RRC
JNC
2427Q
MOV MI
OQ
002406Q
LX!
H
24250Q
MOV CM
INR
L
MOV BM
002414Q
INR
L
MOV MC
I NX
H
MOV MB
002420Q
LHLD
24252Q
I NX H
SHLD
23156Q
LHLD
23156Q
002432Q
I NX
H
SHLD
23156Q
XCHG
MOV AE
002440Q
ANA
I
17Q
SUB 1
OQ
JNZ
251 7Q
LX I H
23156Q
002452Q
MOV
AM
INR L
MOV
BM
SUB I
20Q
002457Q
MOV
CA
MOV AB
SBC
I
OQ
LX I H
24252Q
002466Q
MOV
MC
I NX H
MOV
MA
LHLD
24252Q
002474Q
MOV
AM
I NX H
MOV
BM
LX I H
24252Q
002502Q
MOV
MA
I NX H
MOV
MB
LX I B
2Q
002510Q
LHLD
24252Q
DAD B
SHLD
23156Q
LHLD
23156Q
002522Q
MOV
AM
RET
LX I
H
24256Q
MOV MC
002530Q
I NX
H
MOV MB
LX I
H
23154Q
MOV AM
002536Q
RRC
JNC
2565Q
MOV
MI
OQ
LX I H
24256Q
002547Q
MOV
CM
INR L
MOV
BM
INR L
002553Q
MOV
MC
I NX H
MOV
MB
LHLD
24260Q
002561Q
I NX
H
SHLD
24262Q
LHLD
24262Q
I NX H
002571Q
SHLD
24262Q
XCHG
MOV
AE
ANA I
17Q
002600Q
SUB
I
OQ
JNZ
2633Q
LHLD
24260Q
MOV AM
00261 IQ
1 NX
H
MOV BM
LX I
H
24260Q
MOV MA
002617Q
I NX
H
MOV MB
LX I
B
2Q
LHLD
24260Q
002627Q
DAD
B
SHLD
24262Q
LHLD
242620
MOV AM
002637Q
RET
LX I H
24266Q
MOV
MC
I NX H
002645Q
MOV
MB
INR L
MOV
ME
LX I H
23155Q
002653Q
MOV
AM
RRC
JNC
271 OQ
MOV MI
OQ
002662Q
LX!
H
24266Q
MOV CM
INR
L
MOV BM
002670Q
LX!
H
23162Q
MOV MC
I NX
H
MOV MB
002676Q
LX!
B
20
LHLD
23162Q
DAD
B
SHLD
23160Q
002710Q
LX I
H
24270Q
MOV CM
LHLD
23160Q
MOV MC
002720Q
I NX
H
SHLD
23160Q
XCHG
MOV AE
002726Q
ANA
I
17Q
SUB I
OQ
JNZ
2766Q
CALL
1444Q
002740Q
LHLD
23162Q
MOV MA
I NX
H
MOV MB
002746Q
LX!
H
23162Q
MOV MA
I NX
H
MOV MB
002754Q
LX 1
B
2Q
LHLD
23162Q
DAD
B
SHLD
23160Q
002766Q
RET
LX I H
24272Q
MOV
MC
I NX H
002774Q
MOV
MB
INR L
MOV
ME
I NX H
003000Q
MOV
MD
LX I H
23153Q
MOV
MI
377Q
MOV LI
1 55Q
003010Q
MOV
MI
377Q
LX I H
24272Q
MOV
CM
I NR L
003017Q
MOV
BM
CALL
2366Q
LX I
H
24277Q
MOV MA
003027Q
SUB
I
201Q
JZ
3061 Q
MOV
AM
RLC
003036Q
CMA
RRC
JNC
301 2Q
MOV LI
274Q
003045Q
MOV
CM
INR L
MOV
BM
MOV LI
277Q
003052Q
MOV
EM
CALL
2640Q
JMP
301 2Q
RET
003062Q
LX I
H
24300Q
MOV MC
I NX
H
MOV MB
003070Q
INR
L
MOV ME
I NX
H
MOV MD
003074Q
JMP
3167Q
LX I H
24300Q
MOV
CM
I NR L
003104Q
MOV
BM
CALL
2366Q
LX I
H
24304Q
MOV MA
003114Q
SUB
I
201 Q
ADD I
377Q
SBC
A
MOV CA
003122Q
MOV
AM
RLC
ANA
C
RRC
003126Q
JC
3077Q
MOV AM
RET
LX I H
24302Q
003136Q
MOV
CM
INR L
MOV
BM
CALL
2524Q
0031440
LX I
H
24305Q
MOV MA
SUB
I
201 Q
ADD I
377Q
003154Q
SBC
A
MOV CA
MOV
AM
RLC
003160Q
ANA
C
RRC
JC
3133Q
MOV AM
003166Q
RET
LX I H
23153Q
MOV
MI
377Q
I NR L
003175Q
MOV
Ml
377Q
CALL
3077Q
LX I
H
22743Q
MOV MA
003206Q
CALL
31 33Q
LX I H
22743Q
SUB
M
JNZ
3234Q
003220Q
LX I
H
24304Q
MOV AM
SUB
I
201 Q
JNZ
31 77Q
003231Q
MOV
A!
377Q
RET
XRA
A
RET
003236Q
LX!
H
24306Q
MOV MC
I NX
H
MOV MB
003244Q
DCR
L
MOV CM
INR
L
MOV BM
003250Q
MOV
CB
MOV AC
SUB
I
OQ
JNZ
3262Q
003257Q
MOV
AI
377Q
RET
LX I
H
23153Q
MOV MI
377Q
003267Q
LX!
H
24306Q
MOV AM
INR
L
MOV BM
003275Q
ANA
I
360Q
MOV CA
MOV
AB
ANA I
377Q
003303Q
MOV
BA
CALL
2366Q
LX I
H
2431 IQ
MOV MA
003313Q
SUB
I
201 Q
JZ
3331 Q
MOV
AM
RLC
003322Q
CMA
RRC
JNC
3267Q
XRA A
003330Q
RET
MOV AI
377Q
RET
LX I H
24312Q
003337Q
MOV
MC
I NX H
MOV
MB
LX I H
23153Q
003345Q
MOV
MI
377Q
LX I H
24312Q
MOV
AM
INR L
003354Q
MOV
BM
ANA I
360Q
MOV
CA
MOV AB
003361Q
ANA
I
377Q
MOV BA
CALL
2366Q
LX I H
24315Q
003372Q
MOV
MA
SUB I
201 Q
ADD
I
377Q
SBC A
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 33
180
003400Q
MOV CA
PUSH B
MOV Cl
1 3Q
MOV El
OQ
003406Q
MOV Dl
OQ
CALL
462Q
CMA
POP D
003415Q
ANA E
RRC
JNC
3470Q
LX I H
24315Q
003425Q
MOV AM
RLC
CMA
RRC
003431Q
JNC
3347Q
LX I H
22744Q
MOV AM
RRC
003441Q
JNC
3456Q
LX I H
24315Q
MOV CM
CALL
5260
003453Q
JMP
3465Q
LX I H
24315Q
MOV CM
CALL
573Q
003465Q
JMP
3347Q
RET
MOV Cl
2Q
MOV BI
OQ
003475Q
CALL
1073Q
CALL
1 223Q
RRC
JNC
3527Q
003507Q
CALL
1304Q
MOV LI
11 2Q
MOV MA
MOV Cl
2Q
003517Q
MOV BI
OQ
CALL
1073Q
JMP
3500Q
RET
003530Q
LX I H
24316Q
MOV MC
I NX H
MOV MB
003P36Q
CALL
3471 Q
MOV LI
153Q
MOV MI
377Q
LX I H
24316Q
003550Q
MOV CM
INR L
MOV BM
CALL
23660
003556Q
LX I H
243210
MOV MA
SUB I
201 Q
JZ
3605Q
003567Q
MOV AM
RLC
CMA
RRC
003573Q
JNC
35450
MOV CM
CALL
1243Q
JMP
35f»5Q
003G05Q
RET
LX I H
24322Q
MOV MC
I NX H
003613Q
MOV MB
JMP
4022Q
LX I H
23154Q
MOV MI
377Q
003624Q
LX I H
243240
MOV CM
INR L
MOV BM
003632Q
LX I H
23156Q
MOV MC
I NX H
MOV MB
003640Q
MOV Cl
OQ
MOV BI
00
CALL
2366Q
LX I H
24335Q
003652Q
MOV MA
MOV CA
PUSH B
MOV LI
322Q
003657Q
MOV CM
INR L
MOV BM
CALL
2524Q
003665Q
POP D
SUB E
JNZ
3746Q
LX I H
24335Q
003675Q
MOV AM
SUB I
201 Q
JNZ
37060
MOV A1
377Q
003705Q
RET
CALL
1 223Q
RRC
JNC
3640Q
003715Q
LX I H
24330Q
MOV CM
I NR L
MOV BM
003723Q
MOV LI
326Q
MOV MC
I NX H
MOV MB
003730Q
CALL
1304Q
MOV EA
MOV Cl
OQ
MOV BI
OQ
003740Q
CALL
2640Q
JMP
36400
LX I H
24335Q
MOV AM
003752Q
SUB I
201 Q
JZ
4020Q
MOV LI
324Q
MOV CM
003762Q
INR L
MOV BM
LX I H
231560
MOV MC
003770Q
1 NX H
MOV MB
MOV Cl
OQ
MOV B1
OQ
003776Q
CALL
2366Q
LX I H
23112Q
MOV MA
MOV LI
1 56Q
004007Q
MOV CM
INR L
MOV BM
LX 1 H
24324Q
0040150
MOV MC
I NX H
MOV MB
XRA A
004021Q
RET
LX I H
230720
MOV AM
I NR L
0040270
MOV BM
SUB 1
OQ
MOV CA
MOV AB
004034Q
SBC I
OQ
ORA C
JNZ
40550
LX I H
24330Q
004045Q
MOV Ml
2Q
I NX H
MOV Ml
OQ
JMP
4075Q
004055Q
LHLD
23072Q
1 NX H
SHLD
24330Q
CALL
347 IQ
004067Q
MOV LI
102Q
MOV CM
CALL
1243Q
CALL
1 444Q
004100Q
LX 1 H
242100
MOV MA
I NX H
MOV MB
004106Q
MOV CA
MOV LC
MOV HB
I NX H
004112Q
SHLD
24324Q
LX I H
231550
MOV MI
377Q
LX I H
24330Q
0041250
MOV CM
INR L
MOV BM
MOV LI
326Q
004132Q
MOV MC
I NX H
MOV MB
LHLD
24326Q
004140Q
DCX H
SHLD
243260
XCHG
MOV AE
004146Q
SUB 1
00
MOV EA
MOV AD
SBC I
OQ
0041540
ORA E
ADD I
377Q
SBC A
LX 1 H
22742Q
0041630
MOV MA
CALL
631 Q
CMA
LX I H
22742Q
004173Q
ANA M
RRC
JNC
4320Q
LX I H
24332Q
0042030
MOV Ml
00
I NX H
MOV Ml
00
MOV A1
21 OQ
004212Q
MOV B1
230
LX I H
24332Q
SUB M
INR L
004221Q
MOV CA
MOV AB
SBC M
JC
41350
0042270
CALL
1223Q
RRC
JNC
4300Q
LX I H
24330Q
004241Q
MOV CM
INR L
MOV BM
MOV LI
326Q
004246Q
MOV MC
I NX H
MOV MB
CALL
1 304Q
0042540
MOV EA
LX I H
2421OQ
MOV CM
INR L
004262Q
MOV BM
CALL
2640Q
CALL
361 7Q
RRC
0042720
JNC
43000
MOV AI
3770
RET
LX I H
24332Q
0043030
MOV CM
INR L
MOV BM
LX I H
IQ
00431 IQ
DAD B
SHLD
24332Q
JMP
42100
XRA A
004321Q
RET
LX I H
24437Q
MOV MI
OQ
MOV AI
37Q
0043310
LX 1 H
24437Q
SUB M
JC
4364Q
MOV CM
004341Q
MOV BI
OQ
DCR H
MOV LI
336Q
DAD B
004347Q
DAD B
MOV MI
00
I NX H
MOV MI
OQ
004355Q
LX I H
24437Q
INR M
JNZ
4327Q
RET
004365Q
LX I H
244440
MOV MC
I NX H
MOV MB
004373Q
INR L
MOV Ml
OQ
LX I H
23153Q
MOV MI
377Q
004403Q
LX I H
24444Q
MOV CM
INR L
MOV BM
00441 IQ
CALL
2366Q
LX I H
24447Q
MOV MA
SUB I
20 IQ
004422Q
JZ
4434Q
MOV AM
DCR L
ADD M
004430Q
MOV MA
JMP
4403Q
DCR L
MOV AM
004436Q
ANA I
37Q
MOV LI
370
MOV MA
MOV CA
004444Q
MOV B1
00
DCR H
MOV LI
3360
DAD B
004452Q
DAD B
MOV AM
I NX H
MOV BM
004456Q
LX 1 H
24440Q
MOV MA
I NX H
MOV MB
004464Q
MOV CB
MOV AC
SUB I
OQ
JNZ
4475Q
004473Q
XRA A
RET
MOV LI
37Q
MOV CM
004500Q
MOV B1
OQ
DCR H
MOV LI
336Q
DAD B
004506Q
DAD B
SHLD
24442Q
LX I B
60
LHLD
244400
004520Q
DAD B
XCHG
LX I H
24444Q
MOV CM
004526Q
INR L
MOV BM
CALL
30620
CMA
004534Q
RRC
JNC
4577Q
LX! H
244400
MOV CM
004544Q
INR L
MOV BM
INR L
MOV MC
004550Q
I NX H
MOV MB
LHLD
24440Q
MOV AM
004556Q
I NX H
MOV BM
LX I H
24440Q
MOV MA
004564Q
I NX H
MOV MB
MOV CB
MOV AC
004570Q
SUB I
OQ
JNZ
451 2Q
XRA A
RET
004577Q
MOV At
3770
RET
LX I B
60
LHLD
24440Q
004610Q
DAD B
MOV AM
I NX H
MOV BM
004614Q
MOV CA
CALL
2052Q
LX I B
4Q
LHLD
24440Q
Number 24
181
Page 34
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
004626Q
DAD
B
MOV AM
1 NX H
MOV BM
004632Q
MOV
CA
CALL
2052Q
LHLD
24440Q
MOV AM
004642Q
1 NX
H
MOV BM
LHLD
24442Q
MOV MA
004650Q
I NX
H
MOV MB
LX I H
244400
MOV CM
004656Q
I NR
L
MOV BM
CALL
1 405Q
RET
004664Q
LX 1
H
244500
MOV MC
I NX H
MOV MB
004672Q
CALL
1444Q
LX 1 H
24440Q
MOV MA
1 NX H
004702Q
MOV
MB
MOV LI
370
MOV CM
MOV BI
OQ
004710Q
DCR
H
MOV LI
336Q
DAD B
DAD B
0047150
MOV
AM
1 NX H
MOV BM
LHLD
24440Q
004723Q
MOV
MA
I NX H
MOV MB
LX I H
24437Q
004731Q
MOV
CM
MOV B1
OQ
DCR H
MOV LI
336Q
004737Q
DAD
B
DAD B
XCHG
LX I H
244400
004745Q
MOV
CM
INR L
MOV BM
MOV AC
004751Q
STAX D
1 NX D
MOV AB
STAX D
004755Q
LX I
B
6Q
LHLD
24440Q
DAD B
MOV MI
00
004766Q
I NX
H
MOV Ml
OQ
LX I B
60
LHLD
24440Q
004777Q
DAD
B
XCHG
LX I H
244500
MOV CM
005005Q
INR
L
MOV BM
CALL
2767Q
LX I B
4Q
005015Q
LHLD
24440Q
DAD B
MOV Ml
OQ
I NX H
005024Q
MOV
Ml
OQ
RET
LX I H
24452Q
MOV MC
005033Q
I NX
H
MOV MB
LX I B
4Q
LHLD
24440Q
005043Q
DAD
B
MOV AM
I NX H
MOV BM
005047Q
MOV
CA
CALL
2052Q
LX I B
4Q
LHLD
24440Q
005061Q
DAD
B
XCHG
LX I H
24452Q
MOV CM
005067Q
INR
L
MOV BM
MOV AC
STAX D
005073Q
I NX
D
MOV AB
STAX D
LHLD
24440Q
005101Q
I NX
H
I NX H
PUSH H
LHLD
24452Q
005107Q
I NX
H
XCHG
POP H
MOV ME
005113Q
I NX
H
MOV MD
RET
JMP
5136Q
005121Q
100Q
1 73Q 160Q
163Q 174Q 100Q
1 73Q 162Q
163Q 174Q
056Q 175Q 175Q
005136Q
LX I
H
23155Q
MOV MI
377Q
CALL
1444Q
LX 1 H
2311OQ
005151Q
MOV
MA
I NX H
MOV MB
MOV El
1 000
005156Q
MOV
CA
CALL
2640Q
MOV Cl
00
MOV BI
OQ
005166Q
MOV
El
1 51 Q
CALL
26400
MOV Cl
OQ
MOV BI
OQ
005177Q
MOV
El
155Q
CALL
26400
LX I H
23110Q
MOV CM
00521OQ
I NR
L
MOV BM
CALL
4365Q
LX I H
23112Q
005220Q
MOV
MA
MOV LI
11 OQ
MOV CM
INR L
005225Q
MOV
BM
CALL
46640
LX I H
23110Q
MOV CM
005235Q
INR
L
MOV BM
CALL
1405Q
LX I H
23155Q
005245Q
MOV
MI
377Q
CALL
1 4440
LX I H
2311OQ
MOV MA
005256Q
I NX
H
MOV MB
MOV LI
1 130
MOV MI
OQ
005264Q
MOV
A I
14Q
LX 1 H
23113Q
SUB M
JC
5326Q
005275Q
MOV
CM
MOV Bl
OQ
LX I H
51 21 Q
DAD B
0053040
MOV
AM
MOV EA
LX I H
2311OQ
MOV CM
005312Q
I NR
L
MOV BM
CALL
2640Q
LX I H
23113Q
005322Q
I NR
M
JNZ
5264Q
MOV LI
1 1 OQ
MOV CM
005331Q
I NR
L
MOV BM
CALL
5027Q
RET
005337Q
LX I
H
24162Q
MOV CM
MOV Bl
OQ
LX I H
23164Q
005350Q
DAD
B
DAD B
MOV AM
I NX H
005354Q
MOV
BM
LX I H
244540
MOV MA
I NX H
005362Q
MOV
MB
DCR H
MOV LI
1 62Q
INR M
005367Q
I NR
H
MOV LI
54Q
MOV AM
INR L
005374Q
MOV
BM
RET
LX 1 H
24162Q
INR M
005402Q
MOV
CM
MOV BI
OQ
LX I H
23164Q
DAD B
00541 IQ
DAD
B
MOV AM
I NX H
MOV BM
005415Q
RET
CALL
5337Q
DCR H
MOV LI
21 OQ
005424Q
MOV
MA
1 NX H
MOV MB
RRC
005430Q
JNC
54450
CALL
476Q
LX 1 H
24163Q
MOV CM
005442Q
DCR
L
MOV MC
RET
DCR L
005446Q
MOV
CM
INR L
MOV BM
CALL
3334Q
005454Q
MOV
Cl
1340
CALL
5260
JMP
54160
RET
005465Q
LX I
H
24203Q
MOV AM
ADD A
ORA 1
IQ
005474Q
MOV
MA
LX 1 H
22744Q
MOV MI
3770
RET
005503Q
LX I
H
24203Q
MOV AM
ORA A
RAR
00551 IQ
MOV
MA
RET
LX I B
440Q
CALL
4365Q
005521Q
CMA
RRC
JNC
5534Q
LX I B
440Q
005531Q
CALL
46640
LX I H
23155Q
MOV MI
377Q
CALL
1444Q
005544Q
LX I
H
242100
MOV MA
I NX H
MOV MB
005552Q
LX I
H
22740Q
MOV MA
INR L
MOV MB
005560Q
CALL
61 7Q
LX I H
244560
MOV MA
MOV EA
005570Q
LX I
H
22740Q
MOV CM
INR L
MOV BM
005576Q
CALL
2640Q
LX I H
242100
MOV CM
INR L
005606Q
MOV
BM
CALL
5027Q
LX 1 H
24456Q
MOV AM
005616Q
SUB
I
33Q
RNZ
JMP
56360
0056240
0400 124Q 040Q
116Q 040Q
11 IQ 072Q 040Q
0400 044Q
005636Q
LX I
B
56240
CALL
6430
CALL
61 7Q
LX I H
244560
005652Q
MOV
MA
SUB 1
164Q
JNZ
5666Q
CALL
54650
005663Q
JMP
57160
MOV AM
SUB I
156Q
JNZ
5702Q
0056740
CALL
5503Q
JMP
571 6Q
MOV AM
SUB I
1 51 Q
005705Q
JNZ
57160
LX I SP
22712Q
JMP
403Q
CALL
476Q
005721Q
RET
JMP
57330
005725Q
100Q 173Q 100Q
1 51Q 155Q
1 75Q
005733Q
LX I
H
24170Q
MOV CM
INR L
MOV BM
005741Q
CALL
2052Q
CALL
1 444Q
LX I H
24170Q
MOV MA
005753Q
I NX
H
MOV MB
MOV LI
221 Q
MOV AM
005760Q
RRC
JNC
6043Q
LX I H
23155Q
MOV MI
377Q
005771 Q
LX I
H
24457Q
MOV MI
OQ
MOV AI
5Q
LX 1 H
24457Q
006003Q
SUB
M
JC
6064Q
MOV CM
MOV Bl
OQ
006012Q
LX I
H
5725Q
DAD B
MOV AM
MOV EA
006020Q
LX I
H
24170Q
MOV CM
INR L
MOV BM
006026Q
CALL
2640Q
LX I H
244570
INR M
JNZ
5776Q
006040Q
JMP
6064Q
MOV LI
21 00
MOV CM
INR L
006047Q
MOV
BM
MOV LI
1700
MOV EM
INR L
Number 24
182
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 35
006054Q
MOV DM
CALL
2767Q
MOV LI
221 Q
MOV MI
377Q
006064Q
LX I B
2Q
LHLD
24170Q
DAD B
SHLD
24172Q
006076Q
LX I H
24162Q
MOV Ml
OQ
CALL
5376Q
LX I H
24206Q
00611 IQ
MOV MA
I NX H
MOV MB
CMA
006115Q
RRC
JNC
6133Q
DCR L
MOV CM
006123Q
I NR L
MOV BM
CALL
2052Q
JMP
61 03Q
006133Q
MOV LI
1 62Q
MOV MI
OQ
RET
LX I H
24170Q
006143Q
MOV CM
INR L
MOV BM
LX I H
2311OQ
006151Q
MOV MC
I NX H
MOV MB
LHLD
24170Q
006157Q
MOV AM
1 NX H
MOV BM
LX I H
24170Q
006165Q
MOV MA
I NX H
MOV MB
LX I H
2311OQ
006173Q
MOV CM
INR L
MOV BM
CALL
1 405Q
006201Q
LX 1 B
2Q
LHLD
24170Q
DAD B
SHLD
24172Q
006213Q
RET
LX I H
24460Q
MOV MC
JMP
6271 Q
006223Q
LX I H
24172Q
MOV AM
ANA I
1 7Q
SUB I
OQ
006233Q
JNZ
6264Q
CALL
6140Q
LX 1 H
24170Q
MOV CM
006245Q
INR L
MOV BM
MOV CB
MOV AC
006251Q
SUB I
OQ
JNZ
6264Q
LX I SP
22712Q
JMP
403Q
006264Q
LHLD
24172Q
MOV AM
RET
CALL
6223Q
006274Q
LX I H
24461Q
MOV MA
RLC
RRC
006302Q
JNC
631 7Q
LHLD
24172Q
I NX H
SHLD
24172Q
006314Q
JMP
6271 Q
DCR L
MOV AM
RRC
006322Q
JNC
6336Q
LHLD
24172Q
MOV MI
200Q
I NX H
006333Q
SHLD
24172Q
LX I H
24461 Q
MOV AM
RET
006343Q
LX 1 H
24464Q
MOV MC
DCR H
MOV LI
1 62Q
006352Q
INR M
MOV CM
MOV B1
OQ
LX I H
23164Q
006361Q
DAD B
DAD B
XCHQ
LX I H
22736Q
006367Q
MOV ME
INR L
MOV MD
CALL
1444Q
006375Q
LX I H
24464Q
ORA M
MOV CA
MOV AB
006403Q
ORA I
OQ
LHLD
22736Q
MOV MC
1 NX H
006412Q
MOV MA
LX I H
24164Q
MOV MC
I NX H
006420Q
MOV MA
DCR L
MOV AM
I NR L
006424Q
MOV BM
ANA I
360Q
MOV CA
MOV AB
006431Q
ANA I
377Q
MOV BA
LX I D
2Q
MOV LC
006440Q
MOV HB
DAD D
SHLD
24164Q
LX I H
24166Q
006450Q
MOV MI
OQ
MOV A1
376Q
SUB I
4Q
MOV LI
1 62Q
006460Q
SUB M
JNZ
6526Q
JMP
651 3Q
006467Q
1 1 6Q
123Q 040Q
123Q 124Q 101Q
1 03Q 113Q
040Q 117Q
126Q 105Q 122Q
006505Q
1 1 4Q
1 17Q 127Q
040Q 040Q 044Q
006513Q
MOV Cl
1 IQ
LX I D
6467Q
CALL
446Q
JMP
5Q
006526Q
RET
LX I H
24465Q
MOV MC
DCR H
006534Q
MOV LI
1 66Q
MOV AM
RRC
JNC
6612Q
006543Q
MOV LI
1 62Q
MOV CM
MOV BI
OQ
LX I H
23164Q
006553Q
DAD B
DAD B
MOV AM
I NX H
006557Q
MOV BM
ANA I
360Q
MOV CA
MOV AB
006564Q
ANA I
377Q
MOV EC
MOV DA
LX I H
24465Q
006573Q
MOV CM
CALL
2167Q
MOV LI
1 64Q
MOV MA
006602Q
I NX H
MOV MB
INR L
MOV MI
OQ
006607Q
JMP
6712Q
INR H
MOV LI
65Q
MOV CM
006616Q
LHLD
24164Q
MOV MC
I NX H
SHLD
24164Q
006626Q
XCHG
MOV AE
ANA I
17Q
SUB 1
OQ
006634Q
JNZ
6712Q
LX I H
24164Q
MOV AM
INR L
006644Q
MOV BM
SUB I
20Q
MOV CA
MOV AB
006651Q
SBC 1
OQ
INR H
MOV LI
66Q
MOV MC
006657Q
I NX H
MOV MA
CALL
1 444Q
LHLD
24466Q
006667Q
MOV MA
I NX H
MOV MB
LX I H
24164Q
006675Q
MOV MA
I NX H
MOV MB
LX I B
2Q
006703Q
LHLD
24164Q
DAD B
SHLD
24164Q
RET
006713Q
LX I H
24471Q
MOV Ml
OQ
INR L
MOV MI
377Q
006723Q
MOV Cl
377Q
CALL
621 4Q
LX I H
24473Q
MOV MA
006734Q
SUB I
1 73Q
JNZ
6760Q
DCR L
MOV AM
006743Q
RRC
JNC
6751 Q
DCR L
INR M
006751Q
MOV LI
72Q
MOV MI
377Q
JMP
701 IQ
MOV AM
006761Q
SUB I
1 75Q
JNZ
701 IQ
DCR L
MOV AM
006770Q
RRC
JNC
7001 Q
MOV MI
OQ
JMP
7003Q
007001 Q
DCR L
DCR M
MOV LI
71 Q
MOV AM
007006Q
SUB I
OQ
RZ
MOV LI
73Q
MOV CM
007014Q
CALL
6527Q
JMP
6723Q
RET
MOV Cl
OQ
007025Q
CALL
621 4Q
LX I H
24477Q
MOV MA
SUB I
1 OOQ
007036Q
JNZ
71 26Q
MOV Cl
377Q
CALL
621 4Q
LX I H
23112Q
007051Q
MOV MA
MOV Cl
OQ
CALL
621 4Q
LX I H
24477Q
007062Q
MOV MA
SUB I
1 73Q
JNZ
71 1 IQ
MOV Cl
377Q
007072Q
CALL
621 4Q
LX I H
23112Q
MOV MA
MOV Cl
2Q
007103Q
CALL
6343Q
JMP
7165Q
MOV Cl
1 OOQ
CALL
6527Q
007116Q
MOV Cl
1 OOQ
CALL
6527Q
JMP
71 65Q
MOV AM
007127Q
SUB I
1 73Q
JNZ
7160Q
MOV Cl
377Q
CALL
621 4Q
007141Q
LX I H
23112Q
MOV MA
MOV AI
2Q
ORA I
4Q
007151Q
MOV CA
CALL
6343Q
JMP
71 65Q
MOV Cl
1 OOQ
007162Q
CALL
6527Q
RET
LX I H
24500Q
MOV MC
007172Q
1 NX H
MOV MB
MOV LI
1 1 3Q
MOV MI
OQ
007200Q
MOV Cl
OQ
DCR C
MOV LI
1 1 IQ
MOV MC
007206Q
MOV LI
1 OOQ
MOV CM
INR L
MOV BM
007213Q
MOV CB
MOV AC
RLC
RRC
007217Q
JNC
7246Q
MOV LI
113Q
MOV MI
377Q
XRA A
007227Q
MOV LI
1 OOQ
SUB M
INR L
MOV CA
007234Q
MOV A1
OQ
SBC M
DCR L
MOV MC
007241 Q
I NX H
MOV MA
JMP
7274Q
DCR L
007247Q
MOV AM
INR L
MOV BM
SUB I
OQ
007254Q
MOV CA
MOV AB
SBC I
OQ
ORA C
007261Q
JNZ
7274Q
MOV LI
11 IQ
MOV MI
OQ
MOV LI
1 03Q
007272Q
MOV Ml
60Q
XRA A
LX I H
24500Q
SUB M
007301Q
INR L
MOV CA
MOV AI
OQ
SBC M
007306Q
JNC
7466Q
MOV LI
11 IQ
INR M
MOV CM
007315Q
MOV B1
OQ
MOV LI
103Q
DAD B
XCHG
Page 36
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
183
007323Q
LX I
H
227340
MOV
ME
INR
L
MOV
MD
007331Q
MOV
El
120
MOV
D1
00
LX I
H
24500Q
MOV
CM
007341Q
I NR
L
MOV
BM
JMP
7423Q
MOV
AD
007347Q
CMA
MOV
DA
MOV
AE
CMA
0073530
MOV
EA
I NX
D
LX I
H
00
MOV
A 1
21 Q
007362Q
PUSH H
DAD
D
JNC
73700
XTHL
007370Q
POP
H
PUSH A
MOV
AC
RAL
007374Q
MOV
CA
MOV
AB
RAL
MOV
BA
007400Q
MOV
AL
RAL
MOV
LA
MOV
AH
007404Q
RAL
MOV
HA
POP
A
DCR
A
007410Q
JNZ
7362Q
ORA
A
MOV
AH
RAR
007416Q
MOV
DA
MOV
AL
RAR
MOV
EA
007422Q
RET
CALL
7346Q
LX I
B
60Q
XCHG
007432Q
DAD
B
XCHG
LHLD
22734Q
MOV
ME
007440Q
MOV
El
12Q
MOV
D1
00
LX I
H
24500Q
MOV
CM
007450Q
I NR
L
MOV
BM
CALL
7346Q
LX I
H
245000
007460Q
MOV
MC
1 NX
H
MOV
MB
JMP
7274Q
007466Q
MOV
LI
1 1 30
MOV
AM
RRC
JNC
751 OQ
0074750
MOV
LI
1 1 IQ
INR
M
MOV
CM
MOV
B I
OQ
007503Q
MOV
LI
1030
DAD
B
MOV
MI
55Q
CALL
1 444Q
007513Q
LX I
H
24210Q
MOV
MA
I NX
H
MOV
MB
0075210
LX I
H
23155Q
MOV
MI
3770
LX 1
H
245120
MOV
MI
OQ
007533Q
LX 1
H
2451 IQ
MOV
AM
INR
L
SUB
M
007541 Q
JC
7600Q
DCR
L
MOV
AM
1 NR
L
007547Q
SUB
M
MOV
CA
MOV
BI
OQ
MOV
LI
1 03Q
007555Q
DAD
B
MOV
AM
MOV
EA
LX I
H
2421OQ
007563Q
MOV
CM
INR
L
MOV
BM
CALL
2640Q
007571Q
LX I
H
24512Q
INR
M
JNZ
7533Q
RET
007601Q
LX I
H
24514Q
MOV
MC
I NX
H
MOV
MB
007607Q
I NR
L
MOV
Ml
OQ
I NX
H
MOV
Ml
OQ
007615Q
MOV
LI
1 22Q
MOV
Ml
OQ
LX I
H
23153Q
MOV
Ml
377Q
007626Q
LX I
H
24514Q
MOV
AM
INR
L
MOV
BM
007634Q
ANA
I
360Q
MOV
CA
MOV
AB
ANA
1
377Q
007642Q
MOV
BA
CALL
2366Q
LX I
H
24521 Q
MOV
MA
0076520
SUB
I
201 Q
JZ
77550
MOV
AM
SUB
1
55Q
007662Q
JNZ
7673Q
I NR
L
MOV
MI
377Q
JMP
7626Q
0076730
MOV
AM
SUB
I
60Q
MOV
MA
SUB
1
1 2Q
007701Q
JNC
77520
MOV
Cl
3Q
MOV
LI
1160
MOV
EM
0077110
I NR
L
MOV
DM
MOV
AE
ADD
A
0077150
MOV
EA
MOV
AD
RAL
MOV
DA
007721Q
DCR
C
JNZ
771 30
LHLD
245160
DAD
D
007731Q
XCH0
LHLD
24516Q
DAD
D
XCHG
007737Q
LX I
H
24521Q
MOV
CM
MOV
B I
OQ
XCHG
007746Q
DAD
B
SHLD
24516Q
JMP
7626Q
I NR
L
007756Q
MOV
AM
RRC
JNC
7777Q
XRA
A
0077640
MOV
LI
1 16Q
SUB
M
I NR
L
MOV
CA
0077710
MOV
AI
OQ
SBC
M
MOV
BA
MOV
AC
007776Q
RET
MOV
LI
1160
MOV
AM
I NR
L
010003Q
MOV
BM
RET
LX I
H
24523Q
MOV
MC
01001 IQ
MOV
A 1
71 Q
SUB
M
JC
10023Q
MOV
AM
010020Q
SUB
I
60Q
RET
MOV
AM
SUB
I
1 07Q
010026Q
JNC
10035Q
MOV
AM
SUB
1
67Q
RET
010035Q
MOV
AM
SUB
I
127Q
RET
LX I
H
24524Q
010044Q
MOV
MC
MOV
AM
SUB
1
1 2Q
JNC
10057Q
010053Q
MOV
AM
ADD
1
60Q
RET
MOV
AM
010060Q
ADD
1
1 27Q
RET
LX I
H
24525Q
MOV
MI
IQ
010070Q
CALL
5376Q
LX I
H
24206Q
MOV
MA
I NX
H
010100Q
MOV
MB
CMA
RRC
JNC
10115Q
010106Q
I NR
H
MOV
LI
1250
INR
M
JMP
10070Q
010115Q
MOV
LI
1 63Q
MOV
CM
DCR
L
MOV
MC
010122Q
1 NR
H
MOV
LI
125Q
MOV
AM
RET
010127Q
JMP
10332Q
LX I
H
23154Q
MOV
MI
377Q
LX I
H
24206Q
010142Q
MOV
CM
INR
L
MOV
BM
CALL
2524Q
010150Q
LX I
H
24527Q
MOV
MA
RLC
RRC
010156Q
JNC
10172Q
MOV
AM
SUB
I
201 Q
JNZ
10137Q
0101670
MOV
A 1
377Q
RET
MOV
Cl
OQ
MOV
B I
OQ
010176Q
CALL
23660
LX I
H
24526Q
MOV
MA
RLC
010206Q
RRC
JNC
10222Q
MOV
AM
SUB
I
200Q
010215Q
JZ
10172Q
XRA
A
RET
MOV
AM
010223Q
I NR
L
SUB
M
JZ
10137Q
XRA
A
0102310
RET
RET
LX I
H
24530Q
MOV
CM
010237Q
I NR
L
MOV
BM
LX I
H
23156Q
MOV
MC
010245Q
1 NX
H
MOV
MB
MOV
Cl
OQ
MOV
BI
OQ
010253Q
CALL
2366Q
LX I
H
231120
MOV
MA
LX 1
H
23156Q
0102650
MOV
CM
I NR
L
MOV
BM
LX I
H
24530Q
010273Q
MOV
MC
I NX
H
MOV
MB
MOV
Cl
OQ
010300Q
MOV
B1
00
CALL
2366Q
LX 1
H
24526Q
MOV
MA
01031 IQ
RLC
RRC
JNC
10326Q
MOV
AM
010317Q
SUB
I
201 Q
JNZ
1 0262Q
XRA
A
RET
010326Q
MOV
AI
377Q
RET
RET
LX I
H
24174Q
010335Q
MOV
CM
I NR
L
MOV
BM
1 NR
H
010341Q
MOV
LI
1 30Q
MOV
MC
I NX
H
MOV
MB
010346Q
DCR
H
MOV
LI
206Q
MOV
CM
INR
L
010353Q
MOV
BM
CALL
3236Q
RRC
JNC
1 0365Q
010363Q
XRA
A
RET
LX I
H
24530Q
MOV
CM
010371Q
I NR
L
MOV
BM
LX I
H
23156Q
MOV
MC
010377Q
I NX
H
MOV
MB
CALL
10132Q
RRC
010405Q
JNC
10443Q
LX I
H
24530Q
MOV
CM
I NR
L
010415Q
MOV
BM
DCR
H
MOV
LI
1 76Q
MOV
MC
010422Q
I NX
H
MOV
MB
LX I
H
23156Q
MOV
CM
010430Q
I NR
L
MOV
BM
LX I
H
24200Q
MOV
MC
010436Q
I NX
H
MOV
MB
MOV
AI
377Q
RET
010443Q
LX I
H
24526Q
MOV
AM
SUB
I
201 Q
JNZ
10456Q
010454Q
XRA
A
RET
CALL
1 02330
CMA
Number 24 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
184
Page 37
010462Q
RRC
JNC
10365Q
XRA A
RET
010470Q
RET
CALL
5376Q
LX I H
24206Q
MOV
MA
010500Q
I NX H
MOV
MB
CMA
RRC
010504Q
JNC
10622Q
DCR
L
MOV CM
I NR
L
01 0512Q
MOV BM
CALL
4365Q
CMA
RRC
010520Q
JNC
10534Q
LX I
H
24206Q
MOV CM
INR
L
010530Q
MOV BM
CALL
4664Q
CALL
5376Q
LX I
H
24206Q
010542Q
MOV MA
I NX
H
MOV MB
RRC
010546Q
JNC
10561Q
CALL
1444Q
MOV CA
CALL
5027Q
010560Q
RET
DCR
L
MOV CM
I NR
L
010564Q
MOV BM
CALL
5027Q
LX I H
24162Q
MOV
CM
010574Q
MOV BI
OQ
LX I
H
23164Q
DAD B
DAD
B
010603Q
XCHG
LX I
H
24216Q
MOV CM
I NR
L
01061 IQ
MOV BM
MOV
AC
STAX D
I NX
D
010615Q
MOV AB
STAX D
JMP
10471Q
RET
010623Q
CALL
5376Q
LX I
H
24206Q
MOV MA
I NX
H
010633Q
MOV MB
CMA
RRC
JNC
11Q50Q
010641Q
DCR L
MOV
CM
INR L
MOV
BM
010645Q
CALL
4365Q
CMA
RRC
JNC
10675Q
010655Q
LX I H
24206Q
MOV
CM
INR L
MOV
BM
010663Q
CALL
4664Q
CALL
1 444Q
MOV CA
CALL
5027Q
010675Q
CALL
5376Q
LX I
H
24206Q
MOV MA
I NX
H
010705Q
MOV MB
RRC
RC
LX I
H
23153Q
010713Q
MOV MI
377Q
LX I
H
24206Q
MOV CM
I NR
L
010722Q
MOV BM
CALL
2366Q
LX I H
24532Q
MOV
MA
010732Q
SUB I
201 Q
JZ
10623Q
LX I B
4Q
LHLD
24440Q
010745Q
DAD B
MOV
AM
I NX H
MOV
BM
010751Q
MOV EA
MOV
DB
LX I H
24532Q
MOV
CM
010757Q
CALL
21 67Q
LX I
H
23160Q
MOV MA
I NX
H
010767Q
MOV MB
DCR
L
MOV AM
I NR
L
010773Q
MOV BM
ANA
I
360Q
MOV CA
MOV
AB
011000Q
ANA I
377Q
1 NR
L
MOV MC
I NX
H
011005Q
MOV MA
MOV
LI
155Q
MOV MI
OQ
MOV
Cl
OQ
01 1 014Q
MOV BI
OQ
CALL
2366Q
LX I H
24532Q
MOV
MA
011025Q
SUB I
201 Q
JZ
11045Q
MOV Cl
OQ
MOV
B I
OQ
011036Q
MOV EM
CALL
2640Q
JMP
11012Q
JMP
10623Q
01 1050Q
RET
JMP
11144Q
LX I H
24535Q
MOV
MC
011060Q
LHLD
23160Q
MOV
MC
I NX H
SHLD
23160Q
011070Q
XCHG
MOV
AE
ANA I
1 7Q
SUB
I
OQ
01 1076Q
JNZ
11143Q
LX I
H
23160Q
MOV AM
INR
L
011106Q
MOV BM
SUB
I
20Q
MOV CA
MOV
AB
01 1113Q
SBC I
OQ
LX I
H
24536Q
MOV MC
I NX
H
011122Q
MOV MA
LHLD
24536Q
MOV AM
I NX
H
011130Q
MOV BM
MOV
CA
LX I D
2Q
MOV
LC
011136Q
MOV HB
DAD
D
SHLD
23160Q
RET
011144Q
CALL
5376Q
MOV
CA
CALL
4365Q
CMA
011154Q
RRC
RC
MOV Cl
OQ
DCR
C
011161Q
LX I H
24533Q
MOV
MC
CALL
5376Q
LX I
H
24206Q
011173Q
MOV MA
I NX
H
MOV MB
CMA
011177Q
RRC
JNC
11417Q
INR H
MOV
LI
1 33Q
011206Q
I NR M
LX 1
B
4Q
LHLD
24440Q
DAD
B
011216Q
MOV AM
I NX
H
MOV BM
MOV
CA
011222Q
MOV LC
MOV
HB
I NX H
SHLD
24174Q
011230Q
CALL
10127Q
RRC
JNC
11165Q
LX I
H
24176Q
011242Q
MOV CM
INR
L
MOV BM
LX I
H
23156Q
011250Q
MOV MC
I NX
H
MOV MB
MOV
Cl
OQ
011255Q
MOV BI
OQ
CALL
2366Q
LX I H
23112Q
MOV
MA
011266Q
MOV LI
156Q
MOV
CM
INR L
MOV
BM
011273Q
I NR L
MOV
MC
I NX H
MOV
MB
011277Q
DCR L
MOV
AM
INR L
MOV
BM
011303Q
LX 1 H
24200Q
SUB
M
INR L
MOV
CA
01131 IQ
MOV AB
SBC
M
ORA C
ADD
I
377Q
011316Q
SBC A
INR
H
MOV LI
1 34Q
MOV
MA
011323Q
DCR L
MOV
AM
ORA I
300Q
MOV
CA
011330Q
CALL
11034Q
LX I
H
24534Q
MOV AM
RRC
011340Q
JNC
1 1401Q
LX I
H
23160Q
MOV AM
I NR
L
011350Q
MOV BM
LX I
H
24200Q
SUB M
I NR
L
011356Q
MOV CA
MOV
AB
SBC M
ORA
C
011362Q
ADD I
377Q
SBC
A
INR H
MOV
LI
1 34Q
011370Q
MOV MA
MOV
Cl
200Q
CALL
1 1054Q
JMP
11333Q
011401Q
DCR H
MOV
LI
200Q
MOV CM
1 NR
L
011406Q
MOV BM
MOV
LI
1740
MOV MC
I NX
H
011413Q
MOV MB
JMP
1 1230Q
RET
JMP
1 1 631Q
011423Q
LX I H
24544Q
MOV
AM
INR L
MOV
BM
011431Q
SUB I
OQ
MOV
CA
MOV AB
SBC
I
OQ
011437Q
ORA C
JNZ
1 1445Q
XRA A
RET
011445Q
MOV Cl
OQ
MOV
BI
OQ
CALL
2366Q
LX I
H
24556Q
011457Q
MOV MA
SUB
I
201 Q
JZ
1 1470Q
MOV
AI
377Q
011467Q
RET
XRA
A
RET
LX I
H
24560Q
011475Q
MOV MI
OQ
I NX
H
MOV MI
OQ
LX I
H
23153Q
011505Q
MOV MI
377Q
LX I
B
4Q
LHLD
24440Q
DAD
B
011516Q
MOV AM
I NX
H
MOV BM
LX I
H
2311OQ
011524Q
MOV MA
I NX
H
MOV MB
LX I
H
2311OQ
011532Q
MOV CM
INR
L
MOV BM
CALL
2366Q
011540Q
LX I H
24556Q
MOV
MA
SUB I
201 Q
ADD
1
377Q
011550Q
SBC A
MOV
HI
46Q
MOV CA
MOV
AM
011555Q
INR L
MOV
DM
LX I H
24546Q
SUB
M
011563Q
INR L
MOV
EA
MOV AD
SBC
M
011567Q
ORA E
ADD
I
377Q
SBC A
ANA
C
011574Q
RRC
JNC
1 1623Q
MOV LI
1 56Q
MOV
AM
011603Q
RLC
CMA
RRC
JNC
1 1 527Q
01161 IQ
LHLD
24560Q
I NX
H
SHLD
24560Q
JMP
1 1 527Q
011623Q
MOV LI
1 60Q
MOV
AM
INR L
MOV
BM
011630Q
RET
LX I
B
406Q
CALL
4365Q
CMA
Page 38
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
185
Number 24
186
011640Q
RRC
JNC
11652Q
LX I B
406Q
CALL
4664Q
011652Q
CALL
1444Q
LX I
H
24340Q
MOV MA
I NX H
011662Q
MOV MB
MOV
CA
CALL
5027Q
CALL
3376Q
011672Q
LX 1 H
24204Q
MOV
MA
I NX H
MOV MB
011700Q
CALL
3376Q
LX I
H
24542Q
MOV MA
I NX H
011710Q
MOV MB
CALL
5376Q
LX I H
24212Q
MOV MA
011720Q
I NX H
MOV
MB
CALL
5376Q
LX I H
24214Q
011730Q
MOV MA
I NX
H
MOV MB
MOV LI
204Q
011733Q
MOV CM
INR
L
MOV BM
CALL
4365Q
011743Q
CMA
RRC
RC
LX I H
24542Q
01 1751Q
MOV AM
RRC
JNC
11775Q
MOV LI
146Q
01 1760Q
MOV MI
OQ
I NX
H
MOV MI
OQ
CALL
11472Q
01 1770Q
MOV CA
CALL
7166Q
RET
MOV CM
011776Q
INR L
MOV
BM
CALL
7601 Q
LX I H
24544Q
012006Q
MOV MA
I NX
H
MOV MB
MOV LI
1 57Q
012013Q
MOV MI
OQ
LHLD
24440Q
I NX H
1 NX H
012022Q
MOV AM
I NX
H
MOV BM
LX I H
23156Q
012030Q
MOV MA
I NX
H
MOV MB
LX I H
24550Q
012036Q
MOV MA
I NX
H
MOV MB
LX I H
23155Q
012044Q
MOV MI
377Q
CALL
11423Q
RRC
JNC
12127Q
012055Q
MOV LI
1 56Q
MOV
AM
RLC
CMA
012062Q
RRC
JNC
12046Q
LHLD
24544Q
DCX H
012072Q
SHLD
24544Q
LX I
H
23156Q
MOV CM
INR L
012102Q
MOV BM
LX I
H
24550Q
MOV MC
I NX H
012110Q
MOV MB
MOV
LI
140Q
MOV CM
INR L
012115Q
MOV BM
MOV
LI
156Q
MOV EM
CALL
2640Q
012124Q
JMP
12046Q
LHLD
24440Q
I NX H
I NX H
012134Q
XCHG
LX I
H
24550Q
MOV CM
INR L
012142Q
MOV BM
MOV
AC
STAX D
I NX D
012146Q
MOV AB
STAX
; D
DCR H
MOV LI
21 2Q
012153Q
MOV CM
INR
L
MOV BM
MOV LI
21 OQ
012160Q
MOV MC
I NX
H
MOV MB
INR H
012164Q
MOV LI
1 44Q
MOV
AM
INR L
MOV BM
01 2171Q
SUB I
OQ
MOV
CA
MOV AB
SBC I
OQ
012177Q
ORA C
ADD
I
377Q
SBC A
MOV LI
1 57Q
012205Q
ORA M
RRC
JNC
12225Q
DCR H
012213Q
MOV LI
21 4Q
MOV
CM
INR L
MOV BM
012220Q
MOV LI
21 OQ
MOV
MC
I NX H
MOV MB
012225Q
LX I H
24212Q
MOV
AM
RRC
JNC
1 2261Q
012235Q
CALL
1 444Q
LX I
H
2421OQ
MOV MA
I NX H
012245Q
MOV MB
MOV
EA
MOV DB
INR H
012251Q
MOV LI
1 40Q
MOV
CM
INR L
MOV BM
012256Q
CALL
2767Q
RET
CALL
5376Q
LX I H
24204Q
012270Q
MOV MA
I NX
H
MOV MB
CALL
5376Q
012276Q
LX I H
24206Q
MOV
MA
I NX H
MOV MB
012304Q
CALL
5376Q
LX I
H
24212Q
MOV MA
I NX H
012314Q
MOV MB
CALL
5376Q
LX I H
24214Q
MOV MA
012324Q
I NX H
MOV
MB
MOV LI
21 OQ
MOV MA
012331Q
I NX H
MOV
MB
LX I B
420Q
CALL
4365Q
012341Q
CMA
RRC
JNC
12354Q
LX I B
420Q
012351Q
CALL
4664Q
CALL
1444Q
LX I H
24562Q
MOV MA
012363Q
I NX H
MOV
MB
MOV CA
CALL
5027Q
012371Q
LX I H
24204Q
MOV
CM
INR L
MOV BM
012377Q
CALL
4365Q
CMA
RRC
RC
012405Q
LHLD
24440Q
I NX
H
I NX H
MOV AM
012413Q
I NX H
MOV
BM
LX I H
24174Q
MOV MA
012421Q
I NX H
MOV
MB
LX I H
23153Q
MOV MI
OQ
012430Q
MOV LI
1 55Q
MOV
MI
377Q
CALL
10127Q
RRC
012440Q
JNC
1 2555Q
LX I
H
24174Q
MOV CM
INR L
012450Q
MOV BM
LX I
H
23156Q
MOV MC
I NX H
012456Q
MOV MB
LX I
H
23156Q
MOV AM
I NR L
012464Q
MOV BM
LX I
H
24176Q
SUB M
INR L
012472Q
MOV CA
MOV
AB
SBC M
ORA C
012476Q
JZ
1 2540Q
MOV
Cl
OQ
MOV BI
OQ
CALL
2366Q
01251OQ
LX I H
24565Q
MOV
MA
RLC
CMA
012516Q
RRC
JNC
12457Q
MOV LI
1 62Q
MOV CM
012525Q
INR L
MOV
BM
MOV LI
1 65Q
MOV EM
012532Q
CALL
2640Q
JMP
1 2457Q
MOV LI
21 2Q
MOV CM
012543Q
INR L
MOV
BM
MOV LI
21 OQ
MOV MC
012550Q
I NX H
MOV
MB
JMP
12666Q
LX I H
24174Q
012560Q
MOV CM
I NR
L
MOV BM
LX I H
23156Q
012566Q
MOV MC
I NX
H
MOV MB
LX I H
24200Q
012574Q
MOV MC
I NX
H
MOV MB
LX I H
23155Q
012C02Q
MOV MI
377Q
MOV
Cl
OQ
MOV B I
OQ
CALL
2366Q
012613Q
LX I H
24565Q
MOV
MA
SUB I
201Q
JZ
12666Q
012624Q
MOV AM
RLC
CMA
RRC
012630Q
JNC
1 2604Q
LX I
H
23156Q
MOV CM
INR L
012640Q
MOV BM
LX I
H
24200Q
MOV MC
I NX H
012646Q
MOV MB
INR
H
MOV LI
1 62Q
MOV CM
012653Q
INR L
MOV
BM
MOV LI
1 65Q
MOV EM
012660Q
CALL
2640Q
JMP
12604Q
LHLD
24440Q
I NX H
012672Q
I NX H
XCHG
LX I H
24200Q
MOV CM
0127000
INR L
MOV
BM
MOV AC
STAX D
012704Q
I NX D
MOV
AB
STAX D
MOV LI
21 2Q
01271 IQ
MOV AM
RRC
JNC
12742Q
CALL
1 444Q
012721Q
LX I H
2421OQ
MOV
MA
I NX H
MOV MB
012727Q
MOV EA
MOV
DB
INR H
MOV LI
1 62Q
012734Q
MOV CM
I NR
L
MOV BM
CALL
2767Q
012742Q
RET
CALL
5376Q
MOV CA
CALL
4365Q
012752Q
CMA
RRC
RC
LHLD
24440Q
012760Q
I NX H
I NX
H
PUSH H
LX I B
4Q
012768Q
LHLD
244400
DAD
B
MOV AM
1 NX H
0127740
MOV SM
MOV
CA
MOV LC
MOV HB
0130000
1 NX H
XCHG
POP H
MOV ME
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E,
Menlo Park,
CA 94025
Page 39
Page 40
013004Q
I NX
H
MOV MD
RET
CALL
5376Q
G13012Q
LX 1
H
24566Q
MOV MA
I NX
H
MOV
MB
013020Q
CALL
5376Q
LX I H
24570Q
MOV
MA
I NX
H
01 303CIQ
MOV
MB
RRC
RC
CALL
5376Q
013036Q
LX I
H
24572Q
MOV MA
I NX
H
MOV
MB
013044Q
RRC
JNC
130670
MOV
LI
1 70Q
MOV
CM
01 3053Q
I NR
L
MOV BM
DCR
H
MOV
LI
21 OQ
0 13060Q
MOV
MC
I NX H
MOV
MB
RET
01 3064Q
JMP
13020Q
MOV LI
166Q
MOV
CM
I NR
L
0 ; 3073Q
MOV
BM
I NR L
MOV
EM
I NR
L
oi3077Q
MOV
DM
CALL
30620
RRC
JNC
131240
Ol3107Q
LX I
H
24572Q
MOV CM
I NR
L
MOV
BM
013115Q
DCR
H
MOV LI
2100
MOV
MC
I NX
H
013122Q
MOV
MB
RET
JMP
13020Q
RET
013130Q
CALL
5376Q
MOV CA
CALL
7601 Q
MOV
CA
013140Q
LX I
H
1000000
DAD B
XCHG
LX I
H
22732Q
013150Q
MOV
ME
I NR L
MOV
MD
CALI
5376Q
013156Q
MOV
CA
CALL
76010
MOV
CA
LX I
'h
100000Q
0131660
DAD
B
XCHG
LX I
H
22732Q
MOV
AM
013174Q
I NR
L
MOV BM
SUB
E
MOV
CA
013200Q
MOV
AB
SBC D
JC
13217Q
CALL
5376Q
01321OQ
LX 1
H
2421OQ
MOV MA
I NX
H
MOV
MB
013216Q
RET
CALL
5376Q
LX I
H
242100
MOV
MA
0132260
1 NX
H
MOV MB
CALL
5376Q
LX I
H
2421OQ
013236Q
MOV
MA
I NX H
MOV
MB
RET
0132420
CALL
53760
ANA I
360Q
MOV
CA
MOV
AB
0132510
ANA
I
377Q
LX I H
24204Q
MOV
MC
I NX
H
013260Q
MOV
MA
CALL
5376Q
LX I
H
24212Q
MOV
MA
0132700
I NX
H
MOV MB
MOV
LI
2.1 OQ
MOV
MA
013275Q
I NX
H
MOV MB
CALL
53760
LX I
H
242140
0133050
MOV
MA
I NX H
MOV
MB
MOV
LI
2040
013312Q
MOV
CM
I NR L
MOV
BM
CALL
4365Q
013320Q
RRC
JNC
13362Q
LX I
B
4Q
LHLD
24440Q
013332Q
DAD
B
MOV AM
1 NX
H
MOV
BM
0133360
MOV
CA
CALL
32360
CMA
RRC
013344Q
JNC
13362Q
LX I H
242140
MOV
CM
I NR
L
013354Q
MOV
BM
MOV LI
21 OQ
MOV
MC
I NX
H
013361Q
MOV
MB
RET
LX I
H
245740
MOV
MC
013367Q
CALL
10063Q
MOV LI
1 74Q
SUB
M
SUB
I
2Q
013377Q
1 NR
L
MOV MA
DCR
L
MOV
AM
013403Q
DCR
H
MOV LI
162Q
ADD
M
MOV
MA
01341OQ
CALL
5376Q
ANA I
3600
MOV
CA
MOV
AB
013417Q
ANA
I
3770
MOV BA
CALL
4365Q
CMA
0134260
RRC
RC
CALL
14440
LX I
H
24210Q
013436Q
MOV
MA
I NX H
MOV
MB
LXl
H
23153Q
0134440
MOV
MI
377Q
MOV LI
155Q
MOV
MI
3770
LX I
B
4Q
013455Q
LHLD
24440Q
DAD B
MOV
AM
I NX
H
013463Q
MOV
BM
LX I H
2311OQ
MOV
MA
I NX
H
013471Q
MOV
MB
LX I H
231100
MOV
CM
I NR
L
0134770
MOV
BM
CALL
2366Q
LX I
H
245760
MOV
MA
013507Q
SUB
I
201Q
JZ
1370 IQ
MOV
AM
RLC
013516Q
CMA
RRC
JNC
13543Q
DCR
H
0135240
MOV
LI
21 OQ
MOV CM
I NR
L
MOV
BM
013531Q
I NR
H
MOV LI
176Q
MOV
EM
CALL
2640Q
013540Q
JMP
13472Q
MOV AM
RLC
RLC
013546Q
RRC
JNC
13676Q
MOV
AM
XRA
I
300Q
013555Q
I NR
A
MOV LI
200Q
MOV
MA
MOV
LI
1 75Q
013563Q
MOV
CA
MOV AM
SUB
C
JC
13676Q
013571Q
MOV
LI
200Q
MOV AM
DCR
H
MOV
LI
1 62Q
013577Q
ADD
M
MOV CA
MOV
B I
OQ
LX I
H
23164Q
013606Q
DAD
B
DAD B
MOV
AM
I NX
H
0136120
MOV
BM
LX I H
23110Q
MOV
MA
I NX
H
013620Q
MOV
MB
MOV LI
154Q
MOV
MI
377Q
LX I
H
2311OQ
013630Q
MOV
CM
I NR L
MOV
BM
CALL
2524Q
013636Q
LX I
H
24577Q
MOV MA
SUB
I
201 Q
JZ
13676Q
013647Q
MOV
AM
RLC
CMA
RRC
013653Q
JNC
13625Q
DCR H
MOV
LI
21 OQ
MOV
CM
013662Q
I NR
L
MOV BM
I NR
H
MOV
LI
1 77Q
013667Q
MOV
EM
CALL
2640Q
JMP
13625Q
JMP
134720
013701Q
RET
CALL
5376Q
LX I
H
2421OQ
MOV
MA
01371 IQ
1 NX
H
MOV MB
DCR
L
MOV
CM
013715Q
I NR
L
MOV BM
CALL
3236Q
LX I
H
24221Q
013725Q
MOV
MA
LX I SP
22712Q
JMP
403Q
LX I
H
24601Q
013737Q
MOV
MI
OQ
CALL
5376Q
LX I
H
24206Q
MOV
MA
013750Q
I NX
H
MOV MB
CMA
RRC
013754Q
JNC
1 401OQ
I NR H
MOV
LI
201 Q
MOV
AM
013763Q
RRC
CC
4760
LX I
H
24601Q
MOV
Ml
377Q
0137740
DCR
H
MOV LI
206Q
MOV
CM
I NR
L
01400 IQ
MOV
BM
CALL
3334Q
JMP
137410
RET
01401 IQ
CALL
53760
MOV CA
CALL
7601 Q
LX I
H
22745Q
014023Q
MOV
MA
RET
JMP
14142Q
LX I
H
231010
014033Q
MOV
AM
SUB I
200Q
JNZ
14116Q
MOV
MI
OQ
014043Q
MOV
LI
74Q
MOV CM
I NR
L
MOV
BM
014050Q
MOV
EC
MOV DB
MOV
Cl
240
CALL
462Q
014057Q
SUB
I
OQ
JZ
141160
JMP
14102Q
014067Q
104Q 11 IQ 123Q
113Q 040Q 105Q 117Q 106Q
040Q 040Q
044Q
014102Q
LX 1
B
14067Q
CALL
6430
LX I
H
24603Q
MOV
MI
320
014115Q
RET
LX I H
23101Q
MOV
CM
MOV
B I
00
014124Q
LHLD
23076Q
DAD B
MOV
AM
LX I
H
24603Q
014134Q
MOV
MA
LX I H
23101Q
I NR
M
RET
014142Q
CALL
1444Q
LX I H
242100
MOV
MA
I NX
H
0141520
MOV
MB
LX I H
23155Q
MOV
MI
377Q
DCR
H
01 4161Q
MOV
LI
347Q
MOV AM
RRC
JNC
1 4301 Q
0141 700
CALL
5376Q
LX I H
242060
MOV
MA
I NX
H
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 24
187
Number 24
188
014200Q
MOV
MB
CMA
RRC
JNC
14215Q
014206Q
DCR
L
MOV
CM
I NR
L
MOV BM
014212Q
CALL
3334Q
LX I
B
22750Q
MOV
EC
MOV DB
014222Q
MOV
Cl
12Q
CALL
446Q
CALL
476Q
LX I H
24602Q
014235Q
MOV
MI
10
LX I
H
22750Q
I NX
H
MOV AM
014244Q
LX I
H
24602Q
SUB
M
JC
1441 IQ
I NR M
014254Q
MOV
CM
MOV
BI
OQ
LX I
H
22750Q
DAD B
014263Q
MOV
AM
MOV
EA
LX I
H
2421OQ
MOV CM
014271Q
I NR
L
MOV
BM
CALL
2640Q
JMP
14237Q
014301Q
LX!
H
24604Q
MOV
MI
377Q
CALL
14030Q
LX I H
24603Q
014314Q
MOV
AM
LX I
H
23103Q
SUB
M
RZ
014322Q
LX I
H
246030
MOV
AM
SUB
I
32Q
JNZ
1 4341Q
014333Q
LX I
H
22747Q
MOV
MI
377Q
RET
MOV AM
014342Q
SUB
I
1 40Q
JNZ
14356Q
I NR
L
MOV AM
014351Q
CMA
MOV
MA
JMP
14306Q
MOV AM
014357Q
SUB
I
40Q
SBC
A
CMA
I NR L
014364Q
ANA
M
RRC
JNC
14406Q
DCR H
014372Q
MOV
LI
21 OQ
MOV
CM
I NR
L
MOV BM
014377Q
1 NR
H
MOV
LI
203Q
MOV
EM
CALL
2640Q
014406Q
JMP
14306Q
RET
CALL
1444Q
LX I H
2421OQ
014420Q
MOV
MA
I NX
H
MOV
MB
CALL
5376Q
0144260
LX!
H
2311OQ
MOV
MA
I NX
H
MOV MB
014434Q
MOV
LI
1 53Q
MOV
MI
377Q
MOV
LI
155Q
MOV MI
377Q
0144440
LX!
H
231100
MOV
CM
I NR
L
MOV BM
014452Q
CALL
2366Q
LX I
H
24605Q
MOV
MA
MOV Cl
OQ
0144S3G
MOV
B I
OQ
CALL
2366Q
LX I
H
24606Q
MOV MA
0144740
DCR
L
MOV
AM
SUB
I
201 Q
SUB I
IQ
014502Q
SBC
A
I NR
L
MOV
CA
MOV AM
014506Q
SUB
I
201 Q
SUB
I
IQ
SBC
A
ORA C
014514Q
RRC
RC
DCR
L
MOV CM
014520Q
CALL
10005Q
ADD
A
ADD
A
ADD A
014526Q
ADD
A
MOV
CA
PUSH B
LX I H
24606Q
014534Q
MOV
CM
CALL
10005Q
POP
D
ORA E
014542Q
MOV
EA
LX I
H
24210Q
MOV
CM
I NR L
014550Q
MOV
BM
CALL
2640Q
JMP
14444Q
RET
014560Q
CALL
5376Q
LX I
H
24206Q
MOV
MA
I NX H
014570Q
MOV
MB
RRC
RC
LX I H
23153Q
014576Q
MOV
MI
377Q
MOV
LI
155Q
MOV
MI
377Q
CALL
1444Q
014607Q
LX I
H
2421OQ
MOV
MA
I NX
H
MOV MB
014615Q
LX!
H
24206Q
MOV
CM
I NR
L
MOV BM
014623Q
CALL
2366Q
LX I
H
24607Q
MOV
MA
SUB I
201 Q
014634Q
JZ
1471 IQ
MOV
AM
RLC
RLC
014642Q
RLC
RLC
ANA
I
17Q
MOV CA
014647Q
CALL
1 0041 Q
MOV
EA
LX I
H
2421OQ
MOV CM
014657Q
I NR
L
MOV
BM
CALL
2640Q
LX I H
24607Q
014667Q
MOV
AM
ANA
I
1 7Q
MOV
CA
CALL
1 0041 Q
014676Q
MOV
EA
MOV
Cl
OQ
MOV
BI
OQ
CALL
2640Q
014706Q
JMP
14615Q
RET
CALL
5376Q
ANA I
360Q
014717Q
MOV
CA
MOV
AB
ANA
I
377Q
MOV BA
014724Q
CALL
3530Q
RET
LX I
B
426Q
CALL
4365Q
014736Q
CMA
RRC
JNC
14751Q
LX I B
426Q
014746Q
CALL
4664Q
CALL
5376Q
LX I
H
2461OQ
MOV MA
014760Q
I NX
H
MOV
MB
CALL
5376Q
LX I H
24212Q
014770Q
MOV
MA
I NX
H
MOV
MB
CALL
5376Q
014776Q
LX!
H
24214Q
MOV
MA
1 NX
H
MOV MB
015004Q
CALL
14412Q
LX I
H
23153Q
MOV
MI
377Q
LX I H
2421OQ
015017Q
MOV
CM
I NR
L
MOV
BM
CALL
2366Q
015O25Q
LX 1
H
23113Q
MOV
MA
SUB
I
201 Q
JZ
1 5042Q
015036Q
MOV
CM
MOV
LI
1 02Q
MOV
MC
LX I H
2421OQ
015045Q
MOV
CM
1 NR
L
MOV
BM
CALL
2052Q
015053Q
LX!
H
2461OQ
MOV
CM
I NR
L
MOV BM
015061Q
CALL
3606Q
RRC
JNC
15117Q
LX I H
2421OQ
015073Q
MOV
CM
I NR
L
MOV
BM
CALL
5027Q
015101Q
LX I
H
24212Q
MOV
CM
I NR
L
MOV BM
015107Q
MOV
LI
21 OQ
MOV
MC
I NX
H
MOV MB
0151140
JMP
15143Q
LX I
H
2421OQ
MOV
CM
I NR L
015124Q
MOV
BM
CALL
5027Q
LX I
H
24214Q
MOV CM
015134Q
I NR
L
MOV
BM
MOV
LI
21 OQ
MOV MC
01 5141Q
I NX
H
MOV
MB
RET
CALL
5376Q
01 5147Q
LX I
H
24206Q
MOV
MA
I NX
H
MOV MB
01 51550
CMA
RRC
JNC
15200Q
DCR L
01 51630
MOV
CM
I NR
L
MOV
BM
CALL
4365Q
01 51 71 Q
RRC
CC
4602Q
JMP
15144Q
RET
0152010
LX!
H
24612Q
MOV
MI
OQ
I NX
H
MOV MI
OQ
01521 IQ
CALL
5376Q
LX I
H
24206Q
MOV
MA
I NX H
015221Q
MOV
MB
CMA
RRC
JNC
15256Q
01 5227Q
DCR
L
MOV
CM
I NR
L
MOV BM
0152330
CALL
7601 Q
MOV
CA
LX I
H
246120
MOV EM
015243Q
1 NR
L
MOV
DM
MOV
LC
MOV HB
015247Q
DAD
D
SHLD
24612Q
JMP
1521 IQ
I NR H
0152570
MOV
LI
21 2Q
MOV
CM
I NR
L
MOV BM
0152640
CALL
7166Q
RET
CALL
5376Q
MOV CA
015274Q
CALL
7601 Q
LX!
H
22730Q
MOV
MA
I NR L
015304Q
MOV
MB
CALL
5376Q
MOV
CA
CALL
7601Q
015314Q
LX!
H
22730Q
MOV
CA
MOV
AM
I NR L
015322Q
MOV
DM
SUB
C
MOV
EA
MOV AD
015326Q
SBC
B
MOV
CE
MOV
BA
CALL
71 66Q
0153340
RET
LX I
H
24614Q
MOV
MI
IQ
I NX H
0153430
MOV
MI
OQ
CALL
5376Q
LX I
H
24206Q
MOV MA
015354Q
I NX
H
MOV
MB
CMA
RRC
015360Q
JNC
15477Q
DCR
L
MOV
CM
I NR L
015366Q
MOV
BM
CALL
7601 Q
MOV
CA
LX I H
22726Q
015376Q
MOV
MC
I NR
L
MOV
MB
LX I H
22726Q
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia,
Box E,
Menlo Park,
CA 94025
Page 41
Page 42
015404Q
MOV EM
INR L
MOV DM
LX I H
24614Q
015412Q
MOV CM
INR L
MOV BM
JMP
15463Q
015420Q
MOV AC
SUB E
MOV AB
SBC D
015424Q
JP
15434Q
MOV HB
MOV LC
XCHG
015432Q
MOV BH
MOV CL
LX I H
OQ
XCHG
015440Q
MOV AB
ORA C
RZ
XCHG
015444Q
MOV AB
RAR
MOV BA
MOV AC
015450Q
RAR
MOV CA
JNC
15456Q
DAD D
015456Q
XCHG
DAD H
JMP
15440Q
CALL
15420Q
015466Q
LX I H
24614Q
MOV ME
I NX H
MOV MD
015474Q
JMP
15345Q
INR H
MOV LI
21 4Q
MOV CM
015503Q
I NR L
MOV BM
CALL
7166Q
RET
01551 IQ
CALL
5376Q
MOV CA
CALL
7601Q
LX I H
22724Q
015523Q
MOV MA
INR L
MOV MB
CALL
5376Q
015531Q
MOV CA
CALL
760 IQ
MOV CA
LX I H
22722Q
015541Q
MOV MC
INR L
MOV MB
LX I H
22722Q
015547Q
MOV EM
INR L
MOV DM
INR L
015553Q
MOV CM
INR L
MOV BM
CALL
7346Q
015561Q
MOV CE
MOV BD
CALL
71 660
RET
015567Q
CALL
5376Q
MOV CA
CALL
7601 Q
MOV CA
015577Q
CALL
1 073Q
RET
CALL
5376Q
LX I H
24206Q
01561 IQ
MOV MA
I NX H
MOV MB
CMA
015615Q
RRC
JNC
16003Q
LX I H
23153Q
MOV MI
377Q
015626Q
LX I H
24206Q
MOV CM
INR L
MOV BM
015634Q
CALL
2366Q
LX I H
24621 Q
MOV MA
SUB I
1 57Q
015645Q
JNZ
15673Q
MOV Cl
OQ
MOV B1
OQ
CALL
2366Q
015657Q
SUB 1
1 41Q
SUB I
IQ
SBC A
LX 1 H
23144Q
015667Q
MOV MA
JMP
15603Q
MOV AM
SUB I
1 64Q
015676Q
JNZ
15723Q
DCR H
MOV LI
206Q
MOV CM
015705Q
I NR L
MOV BM
CALL
7601 Q
LX I H
23072Q
015715Q
MOV MA
I NX H
MOV MB
JMP
16000Q
015723Q
MOV AM
SUB I
155Q
JNZ
15747Q
MOV Cl
OQ
015733Q
MOV BI
OQ
CALL
2366Q
LX I H
23103Q
MOV MA
015744Q
JMP
16000Q
MOV AM
SUB I
160Q
JNZ
15765Q
015755Q
LX I H
22744Q
MOV Ml
377Q
JMP
16000Q
MOV AM
015766Q
SUB I
1 44Q
JNZ
16000Q
LX I H
22744Q
MOV MI
OQ
016000Q
JMP
15603Q
RET
CALL
5376Q
MOV CA
01601OQ
CALL
7601 Q
LX I H
22720Q
MOV MA
INR L
016020Q
MOV MB
CALL
5376Q
MOV CA
CALL
7601Q
016030Q
MOV CA
LX I H
22716Q
MOV MC
INR L
016036Q
MOV MB
LX I H
22716Q
MOV EM
INR L
016044Q
MOV DM
INR L
MOV CM
INR L
016050Q
MOV BM
CALL
7346Q
CALL
7166Q
RET
016060Q
LX I H
23150Q
MOV CM
INR L
MOV BM
016066Q
MOV LI
1 1 OQ
MOV MC
I NX H
MOV MB
016073Q
LX I H
24622Q
MOV MI
OQ
I NX H
MOV MI
OQ
016103Q
LX I H
2311OQ
MOV CM
INR L
MOV BM
01611 IQ
MOV CB
XRA A
SUB C
JNC
16145Q
01 6117Q
LHLD
24622Q
1 NX H
SHLD
24622Q
LHLD
2311OQ
01 6131Q
MOV AM
1 NX H
MOV BM
LX I H
2311OQ
016137Q
MOV MA
I NX H
MOV MB
JMP
16103Q
016145Q
LX I H
24622Q
MOV CM
INR L
MOV BM
016153Q
CALL
7166Q
RET
CALL
5376Q
MOV CA
016163Q
CALL
7601 Q
LX I H
22714Q
MOV MA
I NR L
016173Q
MOV MB
CALL
5376Q
MOV CA
CALL
760 IQ
016203Q
MOV EA
MOV DB
LX I H
22714Q
MOV CM
01621 IQ
INR L
MOV BM
CALL
1744Q
RET
016217Q
CALL
1 444Q
LX I H
2421OQ
MOV MA
I NX H
016227Q
MOV MB
LX I H
23155Q
MOV MI
377Q
LX I H
2421OQ
016240Q
MOV CM
INR L
MOV BM
MOV El
63Q
016245Q
CALL
2640Q
MOV Cl
OQ
MOV BI
OQ
MOV El
61 Q
016256Q
CALL
2640Q
MOV Cl
OQ
MOV B1
OQ
MOV El
1 41Q
016267Q
CALL
2640Q
RET
LX I H
24624Q
MOV MC
0162770
I NX H
MOV MB
LHLD
23074Q
MOV MI
OQ
016306Q
LX 1 H
24627Q
MOV MI
IQ
MOV AI
13Q
LX I H
24627Q
016320Q
SUB M
JC
1 6344Q
MOV CM
MOV B1
OQ
016327Q
LHLD
23074Q
DAD B
MOV MI
40Q
LX I H
24627Q
016340Q
INR M
JNZ
16313Q
MOV MI
OQ
MOV LI
231 Q
016350Q
MOV Ml
OQ
LX I H
23153Q
MOV MI
377Q
LX I H
24627Q
016362Q
MOV AM
SUB I
1 3Q
SBC A
MOV CA
016367Q
PUSH B
MOV LI
224Q
MOV CM
I NR L
016374Q
MOV BM
CALL
2366Q
LX 1 H
24630Q
MOV MA
016404Q
SUB I
20 IQ
POP D
ADD I
377Q
SBC A
016412Q
ANA E
RRC
JNC
16513Q
MOV AM
016420Q
SUB I
72Q
JNZ
16443Q
INR L
MOV CM
016427Q
LHLD
23074Q
MOV MC
LX I H
24627Q
MOV MI
OQ
016440Q
JMP
1 6357Q
MOV AM
SUB I
56Q
JNZ
1 6457Q
016451Q
DCR L
MOV MI
1 OQ
JMP
1651OQ
DCR L
016460Q
INR M
MOV CM
MOV BI
OQ
LHLD
23074Q
016467Q
DAD B
PUSH H
LX I H
24630Q
MOV CM
016475Q
CALL
757Q
POP H
MOV MA
LX I H
24630Q
016505Q
MOV CM
INR L
MOV MC
JMP
16357Q
016513Q
CALL
666Q
RET
LX I H
24632Q
MOV MC
016523Q
1 NX H
MOV MB
LX 1 B
1 4Q
LHLD
23074Q
016533Q
DAD B
XCHG
MOV Cl
7Q
PUSH D
016540Q
LX 1 H
24632Q
MOV EM
INR L
MOV DM
016546Q
MOV AD
ORA A
RAR
MOV DA
016552Q
MOV AE
RAR
MOV EA
DCR C
016556Q
JNZ
16546Q
POP H
MOV ME
LX I B
40Q
016566Q
LHLD
23074Q
DAD B
XCHG
LX I H
24632Q
016576Q
MOV AM
INR L
MOV BM
ANA I
1 77Q
016603Q
MOV CA
MOV AB
ANA I
OQ
MOV BA
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
189
01661OQ
MOV AC
STAX D
RET
LX 1 B
14Q
016616Q
LHLD
23074Q
DAD B
MOV
AM
MOV El
7Q
016625Q
ADD A
DCR E
JNZ
16625Q
LX I D
40Q
016635Q
LHLD
23074Q
DAD D
MOV
CA
MOV AM
016643Q
ORA C
MOV CA
MOV
BI
OQ
CALL
7166Q
0165520
RET
CALL
5376Q
MOV
CA
CALL
16273Q
016662Q
CALL
5376Q
MOV CA
CALL
7601 Q
MOV CA
016672Q
CALL
16517Q
CALL
5376Q
LX I
H
2421OQ
MOV MA
016704Q
I NX H
MOV MB
LX I
H
23074Q
MOV CM
016712Q
I NR L
MOV BM
MOV
EC
MOV DB
016716Q
MOV Cl
17Q
CALL
462Q
SUB
I
377Q
JNZ
16741Q
016730Q
CALL
5376Q
LX I H
2421OQ
MOV
MA
I NX H
016740Q
MOV MB
RET
CALL
5376Q
MOV CA
016746Q
CALL
16273Q
MOV Cl
OQ
MOV
BI
OQ
CALL
16517Q
016760Q
CALL
5376Q
LX I H
2421OQ
MOV
MA
I NX H
016770Q
MOV MB
LX I H
23074Q
MOV
CM
INR L
016776Q
MOV BM
MOV EC
MOV
DB
MOV Cl
26Q
017003Q
CALL
462Q
SUB I
377Q
JNZ
17024Q
CALL
5376Q
017016Q
LX I H
2421OQ
MOV MA
1 NX
H
MOV MB
017024Q
RET
CALL
5376Q
LX I
H
2421OQ
MOV MA
0170340
I NX H
MOV MB
LX I
H
23074Q
MOV CM
017042Q
I NR L
MOV BM
MOV
EC
MOV DB
017046Q
MOV Cl
20Q
CALL
462Q
SUB
I
377Q
JNZ
1 7071Q
017060Q
CALL
5376Q
LX I H
2421OQ
MOV
MA
I NX H
017070Q
MOV MB
RET
LX I
H
23074Q
MOV CM
017076Q
INR L
MOV BM
MOV
EC
MOV DB
017102Q
MOV Cl
23Q
CALL
446Q
RET
JMP
17224Q
0171130
LX 1 H
24637Q
MOV AM
SUB
I
OQ
RNZ
017122Q
LX I H
23101Q
MOV CM
MOV
B I
OQ
LHLD
23076Q
0171330
DAD B
XCHG
LX I
H
24635Q
MOV CM
01 7141Q
MOV AC
STAX D
LX I
H
23101Q
I NR M
017147Q
MOV AM
SUB 1
200Q
JNZ
17223Q
MOV LI
74Q
017157Q
MOV CM
INR L
MOV
BM
MOV EC
017163Q
MOV DB
MOV Cl
25Q
CALL
462Q
LX I H
24637Q
017174Q
MOV MA
LX I H
23101Q
MOV
MI
OQ
LHLD
24440Q
017205Q
I NX H
I NX H
XCHG
LX I H
23156Q
017213Q
MOV CM
INR L
MOV
BM
MOV AC
017217Q
STAX D
I NX D
MOV
AB
STAX D
017223Q
RET
LX I H
24637Q
MOV
MI
OQ
LX I H
23101Q
017234Q
MOV Ml
OQ
CALL
5376Q
MOV
CA
CALL
4365Q
017245Q
CMA
RRC
RC
LX 1 B
4Q
0172530
LHLD
24440Q
DAD B
MOV
AM
I NX H
017261Q
MOV BM
MOV CA
MOV
LC
MOV HB
017265Q
1 NX H
SHLD
23156Q
MOV
Cl
OQ
MOV BI
OQ
017275Q
CALL
2366Q
LX I H
24635Q
MOV
MA
SUB 1
201 Q
017306Q
JZ
17317Q
CALL
17113Q
JMP
1 7271Q
LX I H
23154Q
017322Q
MOV MI
377Q
CALL
5376Q
ANA
I
360Q
MOV CA
017332Q
MOV AB
ANA 1
377Q
MOV
BA
CALL
2524Q
017341Q
LX I H
24635Q
MOV MA
SUB
I
201 Q
JZ
17400Q
017352Q
INR L
MOV MI
OQ
MOV
AI
1 77Q
LX 1 H
24636Q
017362Q
SUB M
JC
17400Q
CALL
17113Q
LX I H
24636Q
017374Q
INR M
JNZ
17355Q
CALL
5376Q
LX I H
2421OQ
0174060
MOV MA
I NX H
MOV
MB
INR H
017412Q
MOV LI
237Q
MOV AM
SUB
I
OQ
JZ
17433Q
017422Q
CALL
5376Q
LX I H
2421OQ
MOV
MA
I NX H
017432Q
MOV MB
RET
CALL
3376Q
LX I H
24206Q
017442Q
MOV MA
I NX H
MOV
MB
MOV CA
017446Q
CALL
4365Q
CMA
RRC
JNC
17476Q
017456Q
LX 1 H
24206Q
MOV CM
INR
L
MOV BM
017464Q
CALL
4664Q
CALL
1444Q
MOV
CA
CALL
5027Q
0174760
CALL
5376Q
MOV CA
CALL
760 IQ
LX I H
24640Q
0175100
MOV MA
I NX H
MOV
MB
CALL
5376Q
0175160
LX I H
2421OQ
MOV MA
I NX
H
MOV MB
017524Q
XRA A
LX I H
24640Q
SUB
M
INR L
017532Q
MOV CA
MOV AI
OQ
SBC
M
JNC
17726Q
017541Q
LHLD
24640Q
DCX H
SHLD
24640Q
LX 1 H
23074Q
01 7553Q
MOV CM
INR L
MOV
BM
MOV EC
017557Q
MOV DB
MOV Cl
24Q
CALL
462Q
SUB I
OQ
017567Q
JZ
17604Q
CALL
5376Q
LX 1
H
2421OQ
MOV MA
017601Q
I NX H
MOV MB
RET
LHLD
23076Q
017607Q
MOV AM
LX I D
4Q
LHLD
24440Q
DAD D
017617Q
MOV CA
MOV AM
I NX
H
MOV DM
017623Q
MOV EA
CALL
2167Q
LX I
H
23160Q
MOV MA
017633Q
I NX H
MOV MB
DCR
L
MOV AM
017637Q
INR L
MOV BM
ANA
I
360Q
MOV CA
017644Q
MOV AB
ANA I
377Q
INR
L
MOV MC
017651Q
I NX H
MOV MA
MOV
LI
1 55Q
MOV MI
OQ
017657Q
MOV LI
1 01Q
MOV MI
IQ
MOV
AI
1 77Q
LX I H
23101Q
017670Q
SUB M
JC
17524Q
MOV
CM
MOV BI
OQ
017677Q
LHLD
23076Q
DAD B
MOV
AM
MOV EA
017705Q
MOV Cl
OQ
MOV BI
OQ
CALL
2640Q
LX I H
23101Q
017717Q
INR M
JNZ
17663Q
JMP
17524Q
RET
017727Q
LX I H
22747Q
MOV MI
OQ
INR
H
MOV LI
1 01 Q
017737Q
MOV MI
200Q
CALL
14025Q
RET
JMP
20035Q
017750Q
LX 1 H
24652Q
MOV MC
I NX
H
MOV MB
017756Q
MOV LI
255Q
MOV MI
OQ
MOV
A I
47Q
LX I H
24655Q
017767Q
SUB M
JC
20032Q
MOV
CM
MOV BI
OQ
017776Q
INR L
DAD B
DAD
B
MOV AM
020002Q
I NX H
MOV BM
LX I
H
24652Q
SUB M
020010Q
INR L
MOV CA
MOV
AB
SBC M
020014Q
ORA C
JNZ
20024Q
MOV
LI
255Q
MOV AM
020023Q
RET
MOV LI
255Q
I NR
M
JNZ
17762Q
020032Q
MOV A1
50Q
RET
LX I
H
24162Q
MOV CM
020041Q
INR C
MOV BI
OQ
LX I
H
23164Q
DAD B
Number 24 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
190
Page 43
Page 44
020050Q
DAD B
XCHG
LX 1
H
24216Q
MOV AM
020056Q
INR L
MOV BM
ORA
I
1 IQ
MOV CA
020063Q
MOV AB
ORA I
OQ
MOV
BA
MOV AC
020070Q
STAX D
1 NX D
MOV
AB
STAX D
020074Q
LX I H
24162Q
MOV CM
MOV
BI
OQ
LX I H
23164Q
020105Q
DAD B
DAD B
MOV
AM
I NX H
02011 IQ
MOV BM
RRC
CMA
RRC
020115Q
JNC
20127Q
LX I H
24162Q
DCR
M
JMP
20074Q
020127Q
LX 1 H
24162Q
MOV CM
MOV
B I
OQ
LX I H
23164Q
020140Q
DAD B
DAD B
MOV
AM
I NX H
020144Q
MOV BM
RRC
JNC
20157Q
LX I SP
22712Q
020154Q
JMP
403Q
LX I H
241620
MOV
CM
1 NR L
020164Q
MOV MC
DCR L
MOV
CM
MOV B1
OQ
020171Q
LX I H
23164Q
DAD B
DAD
B
MOV AM
020177Q
I NX H
MOV BM
ANA
I
4Q
MOV CA
020204Q
MOV AB
ANA I
OQ
LX 1
H
24167Q
MOV MC
020213Q
CALL
631 Q
RRC
CC
551 3Q
LX 1 H
24203Q
020225Q
MOV AM
RRC
CC
5416Q
LX I H
24162Q
020235Q
MOV CM
MOV B!
OQ
LX I
H
23164Q
DAD B
020244Q
DAD B
MOV AM
I NX
H
MOV BM
020250Q
ANA I
360Q
MOV CA
MOV
AB
ANA I
377Q
020256Q
LX 1 H
24642Q
MOV MC
1 NX
H
MOV MA
020264Q
DCR H
MOV LI
21 6Q
MOV
CM
I NR L
020271Q
MOV BM
MOV LI
21 OQ
MOV
MC
I NX H
020276Q
MOV MB
LX I B
2Q
LHLD
24642Q
DAD B
020306Q
MOV AM
LX I H
24650Q
MOV
MA
LX 1 B
3Q
020316Q
LHLD
24642Q
DAD B
MOV
AM
LX I H
24651Q
020326Q
MOV MA
SUB I
201 Q
SUB
1
IQ
SBC A
020334Q
LX I D
4Q
LHLD
24642Q
DAD
D
MOV CA
020344Q
MOV AM
SUB I
201 Q
ADD
1
377Q
SBC A
020352Q
ORA C
LX I H
24650Q
MOV
EA
MOV AM
020360Q
SUB I
1 41Q
SBC A
ORA
E
MOV CA
020365Q
MOV A1
1 72Q
SUB M
SBC
A
ORA C
020372Q
RRC
JNC
20407Q
MOV
Cl
OQ
DCR C
020401Q
CALL
13363Q
JMP
21173Q
LHLD
246420
I NX H
020413Q
1 NX H
MOV AM
I NX
H
MOV BM
020417Q
MOV CA
CALL
17750Q
MOV
LA
MOV HI
OQ
020426Q
JMP
21037Q
CALL
10471Q
JMP
21173Q
CALL
13007Q
020442Q
JMP
21173Q
CALL
12262Q
JMP
21173Q
CALL
13242Q
020456Q
JMP
21173Q
CALL
13130Q
JMP
21173Q
CALL
12743Q
020472Q
JMP
211730
CALL
11420Q
JMP
21173Q
CALL
1 1051Q
020506Q
JMP
21173Q
CALL
144120
JMP
21173Q
CALL
1 5201Q
020522Q
JMP
21173Q
CALL
10623Q
JMP
21173Q
CALL
15144Q
020536Q
JMP
21173Q
CALL
15270Q
JMP
21173Q
CALL
15335Q
020552Q
JMP
21173Q
CALL
16004Q
JMP
21173Q
CALL
17434Q
020566Q
JMP
21173Q
CALL
1711OQ
JMP
21173Q
CALL
16653Q
020602Q
JMP
21173Q
CALL
17025Q
JMP
21173Q
CALL
16613Q
020616Q
JMP
21173Q
CALL
16742Q
JMP
21173Q
CALL
17072Q
020632Q
JMP
21173Q
CALL
17727Q
JMP
21173Q
CALL
1 551 1 Q
020646Q
JMP
21173Q
CALL
14560Q
JMP
21173Q
CALL
13734Q
020662Q
JMP
21 173Q
CALL
14712Q
JMP
21173Q
CALL
14730Q
020676Q
JMP
21173Q
CALL
15603Q
JMP
21173Q
CALL
13702Q
020712Q
JMP
21173Q
CALL
16060Q
JMP
21173Q
CALL
5465Q
020726Q
JMP
21173Q
CALL
5503Q
JMP
21173Q
CALL
1 401 IQ
020742Q
JMP
21173Q
CALL
16217Q
JMP
21173Q
MOV Cl
OQ
020755Q
CALL
13363Q
JMP
21173Q
CALL
14025Q
JMP
21173Q
020771Q
CALL
15567Q
JMP
21173Q
CALL
16157Q
JMP
21173Q
0210050
LX I H
23104Q
MOV Ml
377Q
MOV
Cl
OQ
MOV El
OQ
021016Q
MOV D1
OQ
CALL
446Q
JMP
21173Q
MOV Cl
OQ
021030Q
DCR C
CALL
13363Q
JMP
21173Q
DAD H
021040Q
LX I B
21051Q
DAD B
MOV
EM
I NX H
021046Q
MOV DM
XCHG
PCHL
021051Q
031Q 041Q 037Q
04IQ 045Q
041Q 053Q 0410
061Q 041Q
067Q 041Q 075Q
021067Q
103Q 041Q 11 IQ
041Q 117Q
041Q 125Q 041Q
133Q 04IQ
141Q 041Q 147Q
021105Q
155Q 041Q 163Q
041Q 171Q
041Q 177Q 041Q
205Q 041Q
213Q 04IQ 22IQ
021123Q
227Q 041Q 235Q
041Q 243Q
041Q 251Q 041Q
257Q 041Q
265Q 04IQ 273Q
021141Q
301Q 041Q 307Q
04IQ 3150
041Q 323Q 04IQ
331Q 041Q
337Q 04IQ 345Q
021157Q
353Q 04IQ 363Q
041Q 371Q
041Q 377Q 041Q
005Q 042Q
026Q Od2Q
021173Q
LX I H
2421OQ
MOV AM
INR
L
MOV BM
021201Q
ANA I
360Q
MOV CA
MOV
AB
ANA I
377Q
021207Q
DCR L
MOV MC
I NX
H
MOV MA
021213Q
MOV LI
1 63Q
MOV CM
DCR
L
MOV MC
021220Q
LX I H
24162Q
MOV CM
MOV
B I
OQ
LX I H
23164Q
021231Q
DAD B
DAD B
MOV
AM
I NX H
021235Q
MOV BM
CMA
RRC
JNC
21 355Q
021243Q
LX I H
24162Q
MOV CM
MOV
B1
OQ
LX I H
23164Q
021254Q
DAD B
DAD B
MOV
AM
I NX H
0212600
MOV BM
LX I H
24206Q
MOV
MA
I NX H
021266Q
MOV MB
INR L
SUB
M
I NR L
021272Q
MOV CA
MOV AB
SBC
M
ORA C
021276Q
JZ
2131 IQ
MOV LI
206Q
MOV
CM
I NR L
021305Q
MOV BM
CALL
2052Q
LX 1
H
24162Q
MOV CM
021315Q
MOV B1
OQ
LX I H
23164Q
DAD
B
DAD B
021324Q
XCH0
LX I H
24216Q
MOV
AM
I NR L
021332Q
MOV BM
ORA I
1 IQ
MOV
CA
MOV AB
021337Q
ORA I
OQ
MOV BA
MOV
AC
STAX D
021344Q
I NX D
MOV AB
STAX
; D
MOV LI
1 62Q
021351Q
INR M
JMP
21220Q
LX I
H
24172Q
MOV AM
021361Q
ANA I
17Q
SUB I
OQ
JNZ
21376Q
CALL
61 40Q
021373Q
JMP
21431Q
LHLD
24172Q
MOV
AM
SUB I
201 Q
021404Q
SUB 1
IQ
SBC A
LHLD
24170Q
MOV CA
021413Q
MOV AM
1 NX H
MOV
DM
MOV ED
021417Q
PUSH B
XRA A
SUB
E
POP D
021423Q
SBC A
ANA E
RRC
CC
6140Q
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 24
191
021431Q
LX I H
24163Q
MOV CM
DCR C
DCR
L
021437Q
MOV MC
MOV LI
166Q
MOV MI
377Q
LX I
B
2Q
021447Q
LHLD
2421OQ
DAD B
MOV AM
SUB
1
201Q
021456Q
JNZ
21475Q
LX I H
24210Q
MOV CM
INR
L
021466Q
MOV BM
CALL
2052Q
JMP
21664Q
XRA
A
021476Q
LX I H
24167Q
SUB M
JNC
21615Q
MOV
LI
21 OQ
021507Q
MOV CM
INR L
MOV BM
I NR
H
021S13Q
MOV LI
2440
MOV MC
I NX H
MOV
MB
021520Q
LHLD
24644Q
MOV AM
I NX H
MOV
BM
021526Q
MOV CB
XRA A
SUB C
JNC
21551Q
021534Q
DCX H
MOV AM
I NX H
MOV
BM
021540Q
LX I H
24644Q
MOV MA
I NX H
MOV
MB
021546Q
JMP
21520Q
LX I H
24170Q
MOV CM
INR
L
0215560
MOV BM
LHLD
24644Q
MOV MC
I NX
H
021564Q
MOV MB
LX I H
24210Q
MOV CM
INR
L
021572Q
MOV BM
MOV LI
170Q
MOV MC
I NX
H
021577Q
MOV MB
LX I B
2Q
LHLD
24170Q
DAD
B
021607Q
SHLD
24172Q
JMP
21664Q
LX I H
23153Q
MOV
MI
377Q
021622Q
LX I H
2421OQ
MOV CM
INR L
MOV
BM
021630Q
CALL
2366Q
LX I H
24647Q
MOV MA
SUB
I
201 Q
021641Q
JZ
21653Q
MOV CM
CALL
6527Q
JMP
21622Q
021653Q
DCR H
MOV LI
21 OQ
MOV CM
I NR
L
021660Q
MOV BM
CALL
2052Q
RET
LX I
B
420Q
021670Q
CALL
4365Q
CMA
RRC
JNC
21706Q
021700Q
LX I B
420Q
CALL
4664Q
CALL
1444Q
LX I
H
2421OQ
021714Q
MOV MA
I NX H
MOV MB
MOV
CA
021720Q
CALL
5027Q
LX I H
23155Q
MOV MI
377Q
MOV
LI
1 1 3Q
021732Q
MOV MI
2Q
LHLD
23076Q
MOV AM
LX 1
H
23113Q
021743Q
SUB M
JC
21776Q
INR M
MOV
CM
021751Q
DCR C
MOV BI
OQ
LHLD
23076Q
DAD
B
021760Q
MOV AM
MOV EA
LX I H
2421OQ
MOV
CM
021766Q
I NR L
MOV BM
CALL
2640Q
JMP
21734Q
021776Q
RET
MOV Cl
31 Q
MOV El
OQ
MOV
DI
OQ
022005Q
CALL
462Q
LX I H
23105Q
MOV MA
INR
L
022015Q
MOV MA
INR L
MOV MA
RET
022021Q
LX I H
242200
MOV AM
RRC
JNC
22400Q
022031Q
MOV MI
OQ
MOV LI
203Q
MOV MI
OQ
MOV
LI
1 70Q
022041Q
MOV Ml
OQ
I NX H
MOV MI
OQ
LX I
H
23150Q
022051Q
MOV MI
OQ
I NX H
MOV MI
OQ
LHLD
23114Q
022061Q
MOV AM
I NX H
MOV BM
LX I
H
2311OQ
022067Q
MOV MA
I NX H
MOV MB
LX I
B
21 Q
022075Q
LHLD
23074Q
DAD B
MOV AM
SUB
I
1 36Q
022104Q
JNZ
22202Q
LX I B
22Q
LHLD
23074Q
DAD
B
022116Q
MOV AM
MOV CA
CALL
10005Q
ADD
A
0221240
ADD A
ADD A
ADD A
LX I
D
23Q
022132Q
LHLD
23074Q
DAD D
MOV CA
MOV
AM
022140Q
PUSH B
MOV CA
CALL
10005Q
POP
D
0221460
ORA E
MOV BI
OQ
MOV CA
LX I
H
22712Q
022155Q
MOV MC
INR L
MOV MB
LX I
H
22712Q
022163Q
MOV EM
INR L
MOV DM
LX I
B
4000
022171Q
CALL
15420Q
LX I H
23110Q
MOV ME
I NX
H
022201 Q
MOV MD
LX I B
25000Q
LX I H
23110Q
MOV
EM
02221 IQ
INR L
MOV DM
CALL
1744Q
CALL
4322Q
022221Q
CALL
51 16Q
CALL
1444Q
LX I H
24216Q
MOV
MA
022233Q
I NX H
MOV MB
MOV LI
1 62Q
MOV
MI
IQ
022241Q
MOV AI
376Q
LX I H
24162Q
SUB M
JC
22313Q
022252Q
MOV CM
MOV BI
OQ
LX I H
23164Q
DAD
B
022261Q
DAD B
XCHG
LX I H
24216Q
MOV
AM
022267Q
INR L
MOV BM
ORA I
1 IQ
MOV
CA
022274Q
MOV AB
ORA I
OQ
MOV BA
MOV
AC
022301Q
STAX D
I NX D
MOV AB
STAX D
022305Q
MOV LI
1 62Q
INR M
JNZ
22241 Q
CALL
21777Q
022316Q
LHLD
23074Q
I NX H
MOV AM
SUB
I
40Q
022325Q
JZ
22425Q
CALL
21665Q
MOV LI
74Q
MOV
CM
022336Q
INR L
MOV BM
MOV EC
MOV
DB
022342Q
MOV Cl
17Q
CALL
462Q
SUB I
377Q
JZ
22375Q
022354Q
CALL
666Q
LX I H
22747Q
MOV MI
OQ
LX I
B
40Q
022367Q
LHLD
23074Q
DAD B
MOV Ml
OQ
JMP
22425Q
022400Q
LX I H
23104Q
MOV AM
RRC
JNC
22425Q
02241OQ
MOV Ml
OQ
CALL
21777Q
CALL
21665Q
DCR
H
022421Q
MOV LI
347Q
MOV MI
377Q
CALL
5722Q
MOV
Cl
377Q
022432Q
CALL
621 4Q
LX I H
24777Q
MOV MA
SUB
I
1 73Q
022443Q
JNZ
22454Q
CALL
671 3Q
JMP
22430Q
MOV
AM
022455Q
SUB I
1 74Q
JNZ
22472Q
MOV Cl
OQ
CALL
6343Q
022467Q
JMP
22526Q
MOV AM
SUB I
1 OOQ
JNZ
22506Q
022500Q
CALL
7023Q
JMP
22526Q
MOV AM
SUB
I
1 75Q
02251 IQ
JNZ
22522Q
CALL
17745Q
JMP
22526Q
MOV
CM
022523Q
CALL
6527Q
JMP
22430Q
El
HLT
022533Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
Number 24
192
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
OSI’s WORD PROCESSOR
News Release Received: 78 Jan 3
Ohio Scientific announces its new Word Processor OS-WP1.
The OS-WP1 is a text editor which operates at both the
character and line levels. It has internal GET and PUT file
commands which transfer individual files from memory to
disk. The OS-WP1 has a full set of printer control commands
which can be used with virtually any impact or matrix com¬
puter printer or word processing printer. The formatted out¬
put mode allows the user to perform left and right justification
of text without line numbers at a designated width of from
20 to 70 characters.
The OS-WP1 is ideal for writing letters, manuals, reports,
and all normal everyday business forms. It can be used directly
with the Lear Siegler ADM-3A or with the Hazeltine 1500
and is adaptable to virtually any other conventaional CRT
terminal via documentation provided.
The complete Word Processor package, two diskettes and
a manual is now available for only $79.00 for use on any
disk-based Ohio Scientific computer system. Available from
Ohio Scientific, Hiram, OH 44234
TANDY COMPUTERS 1978 CATALOG
News Release Received: 78 March 20
A microcomputer mail-order catalog has just been issued
by Tandy Computers, the newly created retail division of
Tandy Corporation, parent company of Radio Shack.
The 52-page 4-color catalog details a full line of popular
brand microcomputers and accessories, software packages,
parts and literature currently in stock. Kits and fully
assembled micromputer systems listed in the catalog range in
price from several hundred dollars to more than $20,000.
Among the nationally known brands carried are Radio
Shack’s TRS-80, the IMSAI 8080, Vector 1 and 1+, Xitan,
Equinox 100, Polymorphic System 8813, and many others
offering beginners, hobbyists, educators and business users
a wide selection from which to choose.
In addition, the store carries a complete selection of micro¬
processor mainframes, peripherals, software, printed circuit
accessories and discrete parts and literature. The new store
also offers programming assistance and on-premises computer
service. Copies of the new Tandy Computers 1978 Catalog
are available by telephoning toll-free 1-800-433-1679, or
by writing to: Tandy Computers, Dept. R7, P.O. Box 2932,
Fort Worth, Texas 76101
PERCOM’s MINIFLOPPY FOR SS-50 BUS
news release Received: 77 Dec 12
PerCom Data Company has introduced the LFD-400, a
minifloppy disk system for the SS-50 bus. A complete 1 -drive
LFD-400 system includes a controller PC board, PROMware
disk operating system, disk drive and drive power supply,
interconnecting cable, two minidiskettes, an operator’s
manual, and an enclosure to house the drive and drive power
supply.
The controller board includes special low-voltage-drop
regulators, a proprietary “bit shifting” compensation circuit,
an inactivity time-out circuit to increase drive motor life,
and provision for 3 K byte of PROM. The controller PROM
may be used completely independently of the disk and
operating system.
The LFD-400 PROMware DOS, miniDOS tm , allows SS-50
bus owners to use their existing software with simple patches.
The miniDOS tm program includes load and save routines, and
is contained in a 2708 EPROM, and therefore is ready on
power-up.
For more information, contact PerCom Data Company,
Inc., 318 Barnes, Garland, TX 75042 (214) 276-1968.
k
022731Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOO 377Q 120Q OOOQ
022747Q 377Q 120Q OOOQ 001Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
022765Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
023055Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ 170Q
023073Q OOOQ 134Q OOOQ 200Q OOOQ OOOQ 200Q 004Q 176Q OOOQ OOOQ OOOQ OOOQ OOOQ
02311 IQ OOOQ OOOQ OOOQ 006Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
023127Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ 377Q
023145Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
023163Q OOOQ 003Q OOOQ 001Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
023201Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
024207Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ 377Q 377Q OOOQ OOOQ OOOQ
024225Q OOOQ OOOQ 377Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
024243Q OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ OOOQ
024655Q OOOQ 156Q 163Q 145Q 161Q 151Q 156Q 156Q 164Q 147Q 145Q 143Q 162Q 147Q
024673Q 143Q 163Q 163Q 160Q 153Q 141Q 144Q 141Q 163Q 144Q 144Q 163Q 165Q 155Q
02471 IQ 154Q 144Q 166Q 162Q 146Q 167Q 146Q 157Q 146Q 143Q 146Q 162Q 156Q 155Q
024727Q 146Q 144Q 146Q 162Q 144Q 155Q 144Q 165Q 153Q 160Q 1630 163Q 157Q 162Q
024745Q 157Q 151Q 157Q 145Q 170Q 156Q 142Q 164Q 156Q 164Q 146Q 146Q 167Q 166Q
024763Q I860 143Q 154Q 162Q 163Q 172Q 172Q 146Q 163Q 163Q 164Q
NO PROGRAM ERRORS
Page 46 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 24
193
Dr. DoBB'S ToURNALof
COMPUTER
(Calisthenics Orthodontia
Running Light Without Overbyte
Number 25 May 1978 Volume 3, Issue 5
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
SOFTWARE
Programming Language Translation Techniques W.M.McKeeman 4
Yet Another Body Ken Anderson 17
Some additions to Lichen Wang’s Robot Control Language
FORTH for Microcomputers John James 21
Description of a stack-oriented language
Resident Memory Test Systems Terry Ritter 28
Discussion with an example for the M6800
EDITHA: A Revision of the Fylstra KIM-1 Editor Program H. T. Gordon 34
HARDWARE
Proposed Standard for the S-100 Bus George Morrow and Howard Fullmer
Preliminary Specs from the IEEE Microprocessor Standards Committee
40
© David Dameron 1979
DISASSEMBLER FOR Z80
News Release Received: 78 Apr 2
alphaBIT Microsystems announces the UN-Z80 disassem¬
bler, output compatible with the TDL Z80 assembly language.
Features: (1) module to be disassembled can be anywhere in
the memory space in one or multiple extents. (2) program,
byte or word format can be specified for each extent. (3) labels
for forward and backward references are automatically
resolved. (4) display or printer output will generate addresses,
object and source. (5) optionally, source code may be gener¬
ated and stored on disk or tape, for subsequent input to an
assembler, Note: All I/O for UN-Z80 is byte oriented. User is
responsible for providing the necessary interface routines for
I/O, which is facilitated by JUMP vectors.
Price: $35.00 on North Star format floppy diskette or
CUTER format tape cassette. Specify load address of 100H or
2A00H. Inquire about other media. $5.00 additional for any
other load address. $2.00 for documentation only, applicable
to purchase within 21 days. California residents add 6% or
6.5% sales tax. Contact alphaBIT Microsystems, Box 1107,
2000 Center Street, Berkeley, CA 94704.
6800 INDUSTRIAL BASIC
News Release Received: 78 April 4
Wintek 4K BASIC is a 6800 BASIC interpreter optimized
for industrial applications. Control of interrupts, direct mem¬
ory read and write, assembly language subroutine, and flexible
input/output are oriented toward process control and monitor¬
ing. 4K BASIC retains many of the features of an interactive
high level language, including advanced control structures
including FOR. . . NEXT, IF. . .THEN. . . ELSE, and ON. ..
GOTO/ON... GOSUB.
The interpreter may reside in RAM or in PROM. If the
BASIC program is also stored in PROM, the interpreter will
immediately enter the “RUN” mode, allowing unattended
operation in dedicated applications. 4K BASIC is available on
cassette ($95) or in PROM on a WINCE ROM Module ($299).
The source listing ($95) and an OEM license ($2,000) are also
available. WINTEK Corporation, 902 North Ninth Street,
Lafayette, IN 47904; (317) 742-6802.
SOLOS TO NORTHSTAR DOS
News Release Received: 78 March 15
Microcomputer Resources, Inc. announces a software pack¬
age that ties Processor Technology’s SOLOS operating system
to North Star DOS and BASIC. It allows the use of the CUTS
tape port for archive storage of data. The VDMhas start-stop
and speed control which allow changes in speed while the com¬
puter is using it. All three I/O ports are supported through
BASIC, and may be accessed by the *#’ operator. The tape
routines are accessed as I/O devices. The cursor control keys
on the SOL are interfaced to North Star BASIC, allowing most
edits in the line editor without the use of control keys. The
user may change from the VDM to any of the SOLOS output
drivers while running the DOS. Additionally, the package
allows the user to list the directory of a disk while in BASIC.
Documentation for the software is included on the disk. It
includes several example programs written in BASIC, and data
files that explain how to operate the system. This package sells
for $10.00 for the diskette and program, and $2.00 to cover
shipping and handling. Microcomputer Resrouces, Inc., 3000
Medical Park Drive, Suite 107, Tampa, FL 33612; (813) 977-
5940.
MORE AD INFINITUM
Received: 78 March 20
In the spirit of James R. Van Zandt’s “practical cure”
for the software piracy problem, let me propose also that
anyone needing transportation borrow Mr. Van Zandt’s
car and send a small rental ($2.00, say) to the car’s owner,
whose name and address is on the registration certificate.
This rental buys three things: (1) the right to use the car,
(2) a full tank of gasoline, and (3) the right to claim certain
rewards from the owner.
The right to use the car would be valuable for a lot of
us who want an alternative less expensive than the local car
dealer but less underhanded than stealing.
Notice that I recommend that you borrow Mr. Van Zandt’s
car, not mine. If very many people follow his suggestions with
my software, I will not be able to afford to maintain my car
in operable condition, much less fill it with gasoline. And just
as Mr. Van Zandt is not likely to spend very much of his
money (the fruits of his labors) on buying cars for others to
borrow, so I and others in the software business are unlikely to
spend much labor on making software for others to copy.
Yes, I do have a better Idea: when a good program hits
the market (your local computer store or the mail order ads),
buy it. The author has already decided how much he needs
to make on each copy to recover his investment. But if he
sells more than he anticipated, he will be strongly motivated
to write more (and hopefully better) software.
It is my opinion that not only is Mr. Van Zandt’s suggestion
economically unviable, but to suggest it is irresponsible. Such
suggestions can only encourage good programmers like Bill
Gates to withhold their products from hobbyists altogether.
Let us rather encourage programmers to offer low-priced
software by enlarging their market.
Tom Pittman
Number 25 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 3
197
PROGRAMMING LANGUAGE
TRANSLATION TECHNIQUES
BY WILLIAM M. McKEEMAN -
Department of Information Science
U C Santa Cruz
Santa Cruz, CA 95064
The problem of writing a programming language translator
consists of setting the design objective, selecting the tech¬
niques to be used, assembling the tools, carrying out the imple¬
mentation, and finally “proving” the result. Properly done, the
result is an understandable program that can be easily changed,
is relatively machine independent, and is free of features
annoying to its eventual users. In practice this is a big, but
achievable order.
In the following pages the reader will find illustrations of
various principles, techniques and tools useful to the translator
writer. The presentation is tutorial, suppressing some impor¬
tant details in the cause of brevity. Further information,
including a comprehensive list of references, can be found in
Gries [71] and McClure [72].
Some important attributes of a translator are listed in
Table 1.1. Much of the initial planning of an implementation
is concerned with choosing among them. The contents of the
table are too much to assimilate all at once, thus the initial
sections of this paper present two translators, illustrating two
recognition algorithms and a simple code generation scheme.
The paper then proceeds to elaborate upon the theme, work¬
ing up to an organization subsuming most practical translators.
Table 1.1
Translator Attributes
The compiler is written in:
(a) assembly language, or
(bl systems programming language, or
(cl general purpose language.
The recognition algorithm is:
(a) table-driven, bottom up, or
(b) recursive, top-down.
There are simplifications and optimizations on the:
(a) token string, and/or
(b) computation tree, and/or
(c) language-directed code, and/or
(d) machine code.
The main measures of efficiency are:
(a) overall size of the translator, and
(b) minimum memory in which the translator can be run, and
(cl translator speed, and
(d) ease of writing, and
(e) ease of changing the translator, and
(f) speed of generated code, and
(g) density of generated code.
The mutually self-describing grammars in Table 1.2 illus¬
trate a grammatical notation combining the familiar context-
free constructs with regular expression operators. Quoting the
literals [Rohl 67] allows grammatical description down to the
character level if desired. The classes LETTER and CHARAC¬
TER must be extended to reflect the actual available charac¬
ter sets.
Table 1.2
Mutually Self-describing Grammars
GOAL = TOKEN _LIST;
TOKEN_LIST = | TLI | TLN 1 TLL | TLS;
TLI-( | TLN | TLL | TLS) IDENTIFIER;
TLN = (TLI | TLL | TLS) NUMBER;
TLL=(TLI | TLN | TLS) LITERAL;
TLS=TOKEN_LIST SEPARATOR;
IDENTIFIER 12 LETTER+ ;
LETTER = 'A' | 'B' \ 'C' | *D' | 'E' | 'F' | 'G' | 'H' | T
| 'J' | 'K' | 'L' | 'M' I 'N' | 'O' | 'P' | 'Q' | 'R'
| 'S' | T' | 'U' | -V’ | 'W' | 'X' | 'Y' | 'Z' | ;
NUMBER-DIG IT+:
DIGIT = ‘0' | '1' | *2' | '3' | '4' | '5' | '6' 1 '7' | '8' | '9' ;
LITERAL-'"' CHARACTER +
CHARACTER-LETTER | DIGIT | SEPARATOR |.
SEPARATOR- '-' |';' | T| ||'(' |')' |'
GOAL-RULE +;
RULE-IDENTIFIER ' = ' FORM ';';
FORM-DEFINITION ( *|' DEFINITION) *;
DEFINITION-CLASS ('-'CLASS)*;
CLASS=(PRIMARY (I '*' |'+' | NUMBER ))*;
PRIMARY-IDENTIFIER | LITERAL | '(' FORM ')';
Page 4
198
Dr. Dobb's Journal of Computer Calisthenics 8t Orthodontia, Box E, Menlo Park, CA 94025
Number 25
The first grammar (a lexical grammar) describes both
grammars as strings of symbols where the actual detail of the
internal structure of the symbols and separators is given.
Because two identifiers together look like one, a TLI (token
list followed by an identifier) may never be followed by
another identifier. Similar comments apply to quoted items
and numeric items. The second grammar (a grammar-grammar)
describes both grammars as sequences of rules where the
symbol (‘ I ’) separates alternatives. Within a definition we may
take the difference between two phrase classes (‘—’) or repeat
them (**’. *+’. INTEGER). We will use this notation exten¬
sively in the following pages.
A translator accepts a source text convenient for program¬
ming and transforms it into a target code suitable for execut¬
ing. To understand the translation process, one must first have
a good grasp of the meaning of a source text and a target code.
For example, the source text
A = — A+5* B/(B —1);
might be translated in the following zero-address target code:
LIT A;
LIT A;
LOAD;
NEG;
LIT 5;
LIT B;
LOAD;
MUL;
LIT B;
LOAD;
LIT 1;
NEG;
ADD;
DIV;
ADD;
STORE;
Table 1.5
Table 1.3 is a grammar for assignment statements. Given
that the variables must contain integers, such statements have
well defined meanings. We presume that the reader is familiar
enough with Algol or PL/1 to be able to follow such examples
as well as simple programs.
Table 1.3
A S' ;:rce Language Grammar
ASSIGNMENT = VARIABLE ' = ’ EXPRESSION ;
EXPRESSION = C!'-')TERM ( f ' + ' | 1 - ’)T1-RM) * ;
TERM = PRIMARY (('*'|'/') PRIMARY)* ;
PRIMARY = CONSTANT j VARIA3I.E | '(' EXPRESSION ;
VARIABLE = IDENTIFIER ;
Note: CONSTANT and IDENTIFIER are processed in the scanner,
making their definition here irrelevant.
Table 1.4 is a grammar for the zero-address target code in
the example above. Even though the meaning of the target
code is probably obvious to our readers, we will use a few
words to describe it.
There is an evaluation stack into which values can be
pushed. Furthermore, the top values (hence the last ones
pushed into the stack) are available to be used in computa¬
tions. The LIT instruction pushes one value onto the stack.
The value is either an address (e.g., the address of the variable
A in LIT A) or a constant (e.g., the value 5 in LIT 5). The
LOAD instruction assumes the top value on the stack is an
address. The address is removed from the stack and the value
found in the indicated cell in memory is pushed onto the stack
in its place. The STORE instuction must be supplied with two
items at the stack top. One is the address of a cell in memory.
The other is a value to be stored into the indicated cell (the
address is below the value in the stack). After the instruction
has completed its action, both address and value are removed
from the stack. The remainder of the instructions are arith¬
metic operations. NEG changes the sign of the top value on
the stack and leaves it where it found it. ADD, MUL and DIV
operate on the two top elements on the stack, removing them
and then placing the result back on the stack.
For both the top-down and bottom-up translators, the
example above will be worked in detail.
The step-by-step execution of the example zero-address
target code is depicted in Figure 1.1.
Table 1.4
A Target Language Grammar
ASSIGNMENT = VARIABLE EXPRESSION 'STORE' ;
EXPRESSION = 'LIT' CONSTANT | VARIABLE 'LOAD'
| EXPRESSION 'NEG'
| EXPRESSION EXPRESSION ('ADD'|'MUL' | ' DIV') ;
VARIABLE = 'LIT' IDENTIFIER ;
Note: Both IDENTIFIER and CONSTANT are represented by bit
patterns in the machine code. The first is to be interpreted as the
address of the variable and the second as the value of the corresponding
constant in the source language.
Successive stack configurations during execution of the code in Table 1.5.
Note: M(A) = 7, M(B) = 6.
ill ill HI II 11
LIT A LIT A LOAD NEG LIT 5 LIT I
1 -1
6 B 6 6 6 5
5 30 30 30 , 30 30 30
[ij HI 11 11 HI 111 111
LOAD MUL LIT B LOAD LIT 1 NEG ADD
ill 11 U
DIV ADD STORE
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
199
2. A Top-down Translator
The recursive recognition technique is one of those ideas
that is so simple that nobody ever bothers to write much
about it. It is, however, often the easiest method of writing
good translators. The prerequisites are a syntactic definition of
the source language (which then becomes the translator writ¬
er’s flow chart) and a recursive language in which to write
(e.g., assembler, PL/360, Algol and PL/1 but not Fortran or
XPL). A partial narration of the program carrying out the
translation depicted in Table 1.5 follows. Refer to Figure 2.1
and Table 2.1.
Initially (line 85), token is undefined and is then set to
‘A’ by the first call of scan (line 87). Then assignment is called,
immediately calls variable (line 16) which checks to make sure
an identifier has been found (line 77) (notice that we hid this
decision inside the undefined function identifier to avoid
unnecessary detail). Since ‘A’ is an identifier, the test is passed
and the pair ‘LIT’ ‘A’ is emitted, and ‘A’ is discarded by a
second call of scan (line 81), leaving *=’ in token. Returning
from variable to assignment (line 16) the *=’ is noted, then
discarded and replaced by the next token The right-hand
side of the assignment is then processed with a call to expres¬
sion. Table 2.1 gives a complete summary of the remaining
actions; the reader is encouraged to complete the simulation
of the recursive translator.
The success of the recursive technique is due to several
circumstances. First, the mapping from a syntactic descrip¬
tion to a recognizer (Table 1.3 to Figure 2.1) is so simple that
an experienced programmer can do it as fast as he can write,
although Frank DeRemer points out that the simplicity rapidly
disappears if good diagnostics and error recovery are required.
Second, the programmer can insert his generator code between
any two statements of the recognizer. This implies that when¬
ever any structure entity of the source language has been
recognized, the programmer has a convenient opportunity to
attach an interpretation to it. Third, because the local variables
of recursive procedures are in fact in a run-time stack, the pro¬
grammer may associate temporary information with any
source language construct (see the variables t in procedures
expression and term, lines 24 to 42) without laboriously build¬
ing stack data structures in his translator. One must reflect on
the pervasive nature of stacks in translators to appreciate the
value of getting them for “free”. Perhaps the most important
advantage of the recursive technique, aside from its simplicity,
is the fact that it can handle complex languages without catas¬
trophic costs in size or speed.
The recursive technique is of no particular help beyond the
production of a language-directed code (e.g., zero-address
code for assignments). Since the great bulk of the work in
writing a compiler for the average modern computer comes in
turning the language-directed code into good machine
language, the helpful properties detailed above can look rather
irrelevant to a hard-pressed implementor.
In addition to the need for a recursive language in which to
write, the recursive technique has one serious disadvantage.
The generator and parser are thoroughly mixed together, pre¬
venting the programmer from treating them separately for pur¬
poses of documentation, maintenance, memory management,
testing, and so forth. In particular, it is hot unusual to find
target code dependencies in the source language recognizer,
which prevent the recognizer from being machine independent.
Figure 2.1
A Simple Recursive Translator for Assignments into Zero-address Code
1 translate:
2 procedure;
3 /* scan and emit are left undefined in this
4 example to avoid irrelevant detail */
5 scan:
6 procedure returns (character varying);
7 /* produces the next token each time called *,
8 end scan;
9 declare token character varying;
10 emit:
11 procedure (op character varying);
12 /* assembles zero-address code */
13 end emit;
14 assignment:
15 procedure;
16 call variable;
17 if token = '=' then token = scan;
18 else call error;
19 call expression;
20 call emit ('STORE');
21 end assignment;
22 expression:
23 procedure;
24 declare t character (1);
25 /* check for unary minus */
26 if token = '-' then
27 do;
28 token = scan;
29 call term;
30 call emit ('NEG');
31 end;
32 else call term;
33 do while token = '-’ I token = '+';
34 t=token;token =scan;
35 call term;
36 if t = '-' then call emit ('NEG') ;
37 call emit ('ADD');
38 end;
39 end expression;
40 term:
41 procedure;
42 declare t character (1) ;
43 call primary;
44 do while token = '*' I token = 7';
45 t = token;token = scan;
46 call primary;
47 if t = '*'then call emit ('MUL');
48 else call emit ('DIV');
49 end;
50 end term;
51 primary:
52 procedure;
53 /* check for a constant */
54 if constant (token) then
55 do;
56 call emit ('LIT') ;
57 call emit (token) ;
58 token = scan;
59 end;
60 /* check for parenthesized expression */
61 else if token = '(' then
62 do;
63 token - scan;
64 call expression;
65 if token = ')' then token = scan;
66 else call error;
67 end;
68 /* assume that it is a variable */
69 else
70 do;
71 call variable;
72 call emit ('LOAD');
Page 6 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
200
Number 25
73 end;
74 end primary;
75 variable:
76 procedure;
77 if identifier (token) then
78 do;
79 call emit ('LIT');
80 call emit (token);
81 token = scan;
82 end;
83 else call error;
84 end varaible;
85 /* main body of translator */
86 /* get initial token value */
87 token = scan;
88 call assignment;
89 end translate;
44
45
46
54
61
71
77
80
81
72
47
* B/(B-1)
B /(B-1)
B /(B-1)
/ (B-1)
/ (B-1)
/ (B-1)
LIT B
LOAD
MUL
Table 2.1
Summary of the Actions of the Top-down Translator
Active line
in the
top-down
recognizer
start
87
88
16
77
80
81
17
19
26
28
43
54
61
69
71
77
80
Value
of
token
undefined
A
Source text
remaining
A= -A + 5*B/(B-1)
= -A+5* B/(B-1)
= -A+5* B/(B-1)
-A + 5*B/(B-1)
A + 5* B/(B-1)
+5* B/(B-1)
Target code
produced
LIT A
44
45
46
54
61
63
64
26
32
43
54
61
71
77
80
81
72
44
33
34
35
43
54
57
58
B-1)
- 1 )
- 1 )
1 )
1 )
LIT B
LOAD
LIT 1
A
+5 *B/ (B-1)
LIT A
44
81
+
5* B/(B-1)
LOAD
36
)
NEG
72
+
5*B/(B-1)
37
)
ADD
44
33
30
65
+
5* B/IB-1)
NEG
47
33
48
34
5
* B/(B -1)
44
DIV
35
36
43
37
54
ADD
57
33
5
*B/(B-1)
LIT 5
20
58
STORE
89
Number 25
Dr. Oobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Page 7
201
3. A Bottom-Up Translator
The actions of a bottom-up translator separate into the
actions that produce the canonical parse and those which the
synthesizer takes when acting on the canonical parse. Because
the canonical parse is most easily understood in relation to a
context-free grammar, Table 3.1 is substituted for Table 1.3
without changing the source language. The procedure synthe¬
size (Figure 3.1, line 47), called with the sequence of rule
numbers in the left-hand column of Table 3.2, will produce
the sequential language-directed code in the right-hand
column of Table 3.2.
The remainder of Figure 3.1 is a source language indepen¬
dent parsing algorithm driven by the mixed LR(0), LR(1)
recognition tables in Table 3.3. The tables are interrogated in
parse (line 100) where state_type is set to the values 0
through 3 corresponding to the tabulated entries blank, S, SR
and R which in turn stand for syntax error, stack the present
state and apply rule N, and apply rule N.
Table 3.1
Context-free Grammar for the Assignment Source Language
rule number rule
1 ASSIGNMENT=VARIABLE '=' EXPRESSION ;
2 EXPRESSION=TERM
3 | TERM
4 | EXPRESSION ' + ' TERM
5 | EXPRESSION'-'TERM;
6 TERM = PRIMARY
7 | TERM ""PRIMARY
8 | TERM 7'PRIMARY;
9 PRIMARY=CONSTANT
10 | VARIABLE
11 I'C EXPRESSION ')’ ;
12 VARIABLE = IDENTIFIER;
Figure 3.1
A Bottom-up Translator
1 translate:
2 procedure;
3 /* auxiliary procedures V
4 /* token handlers */
5 scan:
6 procedure returns (character varying);
7 /* produces next token each time it is called */
8 end scan;
9 /* global residence of the current token */
10 declare token character varying;
11 unscan:
12 procedurels character varying);
13 /* reverses the effect of scan */
14 end unscan;
15 /* stack handlers */
16 /* global residence of last token stacked or uncovered */
17 declare top _of —token —Stack character varying;
18 /* global residence of last state stacked or uncovered */
19 declare top_of—state-stack fixed;
20 push:
21 procedurels fixed, t character varying);
22 /* push s onto the state stack and t onto the
23 token stack, s and t are resident in
24 top_of—state—stack and top_of_token —stack */
25 end push;
26 pop:
27 procedure!n fixed);
28 /* discards n items from each stack, placing
29 newly uncovered values in top—variables */
Page 8
202
30 end pop;
31 /* LR table access */
32 table:
33 procedurels fixed, t character varying)
34 returnsla fixed, n fixed);
35 /* two-valued procedure returning values found;
36 in Table 3.3 */
37 end table;
38 left_part:
39 procedurelp fixed) returnslt character varying);
40 /* t is the left part of rule p in Jable 3.1 */
41 end left—part;
42 length:
43 procedurelp fixed) returnslk fixed);
44 /* k is the number of items on the right side
45 of rule p in Table 3.1 */
46 end length;
47 synthesize:
48 procedurelp fixed);
49 emit:
50 procedurelop character varying);
51 /* assembles one item of zero-address code */
52 end emit;
53 /* switch on rule number */
54 do case p;
55 /* no rule number zero */
56
57 /* ASSIGNMENT- VARIABLE '=' EXPRESSION 'J.' •/
58 do;
59 call emit('STORE') ;
60 return from translate;
61 end;
62 /« EXPRESSION = TERM */
63
64 /* EXPRESSION = '-'TERM */
65 call emit('NEG');
66 /* EXPRESSION" EXPRESSION '+’ TERM */
67 call emit('ADD');
68 /* EXPRESSION EXPRESSION '-' TERM */
69 do;
70 call emit('NEG');
71 call emit('ADD');
72 end;
73 /* TERM = PRIMARY */
74 ;
75 /* TERM = TERM '+' PRIMARY */
76 call emit('MUL') ;
77 /* TERM = TERM T PRIMARY */
78 call emit('DIV') ;
79 /* PRIMARY = CONSTANT */
80 do;
81 call emit('LIT');
82 call emitltop—of—token—stack);
83 end;
84 /* PRIMARY = VARIABLE */
85 call emit('LOAD');
86 /* PRIMARY = '(' EXPRESSION ')' */
87
89 do;
90 call emit!'LIT') ;
91 call emit (top_of—token—stack);
92 end;
93 end;
94 end synthesize;
95 parse:
96 procedure;
97 declare (state—type, N) fixed;
98 do forever;
99 /• get the values from Table 3.3 */
Number 25
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
100
state-type, N = table!top_of_state_stack, token);
118
call synthesize(N);
101
do case state—type;
119
call pop(length(N));
102
/* syntax error */
120
call unscan(token) ;
103
call error;
121
token = left—part(n);
104
/* stack */
122
end;
105
do;
123
end;
106
call pushln, token);
124
end;
107
token = scan;
125
end parse;
108
end;
126
/* main body of translate */
109
/* stack and reduce, LR(O) case */
127
/* initialize read-only syntax tables */
110
do;
128
call initialize—tables;
111
call push(0, token);
129
/* initialize the stacks */
112
call synthesize(N);
130
call push(1,' ');
113
call popOength(N));
131
/* read the first token of the source text */
114
token = left—part(N);
132
token = scan;
115
end;
133
call parse;
116
/* reduce, LR(1) case */
134
end translate;
117
do;
Table 3.2
Association of the Canonical Parse and Code Generation
rule applied emitted code
partially parsed text
A=-A+5*B/(B-1)|
12 VARIABLE=IDENTIFIER LIT A
VARIABLE “-A+5* B/ (B—1)
12 VAR I ABLE “IDENTIFIER LIT A
VARIABLE = -VARIABLE+5*B/(B-lU
10 PRIMARY “VARIABLE LOAD
VARIABLE “-PRIMARY+5* B/(B-1)
6 TERM “PRIMARY
VARIABLE “-TERM +5* B/<B-1) J_
3 EXPRESSION “-TERM NEG
VARIABLE “EXPRESSION+5 *B/<B—1)
9 PRIMARY “CONSTANT LIT 5
VARIABLE “EXPRESSION +PRIMARY * B/(B-1) J_
6 TERM “PRIMARY
VARIABLE = EXPRESSION + TERM* B/IB-1) J_
12 VARIABLE “IDENTIFIER LIT B
VAR IABLE = EXPR ESSION +TERM* VARIABLE/(B-1(J_
10 PRIMARY “VAR I ABLE LOAD
VARIABLE = EXPRESSION+TERM*PRIMARY/ (B-1) J_
7 TERM “TERM‘PRIMARY MUL
VARIABLE = EXPRESSION + TERM/ (B-1)|
12 VARIABLE “IDENTIFIER LIT B
VARIABLE = EXPRESSION + TERM/ (VARIABLE-1) J_
10 PRIMARY “VARIABLE LOAD
VARIABLE = EXPRESSION + TERM/ (PRIMARY-1)
6 TERM “PRIMARY
VARIABLE“EXPRESSION+TERM/ (TERM-lH
2 EXPRESSION “TERM
VARIABLE “EXPRESSION+TERM/ (EXPRESSION-lH
9 PRIMARY “CONSTANT LIT 1
VARIABLE “EXPRESSION + TERM/ (EXPRESSION-PRIMARY)]^
6 TERM“PRIMARY
VARIABLE “EXPRESSION+TERM/ (EXPRESSION-TERM) J_
5 EXPRESSION “EXPRESSION-TERM NEG ADD
VAR I ABLE “EXPRESSION+TERM/ (EXPRESSION) |
11 PRIMARY = (EXPRESSION)
VAR I ABLE “EXPRESSION + TERM/ PRIMARY
8 TERM “TERM/PRIMARY DIV
VARIABLE = EXPRESSION+TERM|
4 EXPRESSION “EXPRESSION + TERM ADD
VARIABLE = EXPRESSION|
1 ASSIGNMENT “VAR I ABLE “EXPRESSION]^ STORE
ASSIGNMENT
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 9
203
Translation starts on line 126 where the syntax tables are
initialized, the initial state is stacked and the initial value of
token is scanned. The recognizer is called and the loop on line
98 is entered. The variables state_type and N are assigned the
values 2 (i.e., entry SR) and 12 (the intersection of row
IDENTIFIER and column 1 of Table 3.3). The case statement
selects the stack-and-reduce case (line 109) where a dummy-
state (0) and the identifier ‘A’ are stacked. Synthesize is called
with parameter 12 (line 112) (line 54) selects the last case (line
88) causing ‘LIT’ ‘A’ to be emitted. Returning to the parser
(line 113) one item is popped off each stack, leaving the initial
state (1) exposed. Token is set to VARIABLE. Execution
continutes on line 100 where state-type and N assume new
values 1 and 15, respectively.
There are programs that produce syntax tables similar to
Table 3.3 from input similar to Tables 3.1 or 1.3. How it is
done is an interesting subject but of no direct concern to the
translator implementor who need only write the procedure
synthesize. There are, however, fewer opportunities to attach
interpretations to the parsing actions since synthesize is called
only from SR and R decision and not S decision. And, except
for the state and token stack, the programmer must build his
own data structures.
Tabic 3.3
Syntax Tables for Mixed l.R(O) and LR(1) Parsing Algorithm
state
12345 6 789 10_11_12 13 14 15
SR R R R R
1 2 3 4 5
S S S S S S S
C 3 3 3 3 3 3 3
SR R R R R
) .
s
= ... 2
S S R R R R
♦ ..4_4_2_3_4_5_
S S SSRRRR
55 662345
S S S S
7 7 7 7
S S S S
/ 8 8 8 8
ASSIGNMENT
EXPRESSION
S S
9 10
S S S S S
TERM
11 11 13 12 14
SR SR SR SR SR SR SR
PRIMARY
6 6 6 6 6 7 8
SR SR SR SR SR SR SR
CONSTANT
9 9 9 9 9 9 9
S SR SR SR SR SR SR SR
VARIABLE
IS 10 10 10 10 10 10 10
SR SR SR SR SR SR SR SR
IDENTIFIER 1
12 12 12 12 12 12 12 12
Tabic 3.3 is equivalent to LALR(l) parsing tables [UcRcmcr b9]
4. An Elaborate Compiler
A compiler accepts source text records and produces
records full of machine code ready for execution. During the
process the program may assume several intermediate forms,
including:
records
string of characters
string of tokens
phrase-structure tree
computation tree
language -specific sequential code
machine-specific sequential code
records
The design of a translator depends heavily on which of the
above forms are to be used. Generally speaking, the more com¬
plex the source text, the higher the payoff in making the com¬
piler more elaborate. Once the sequence of intermediate forms
has been chosen, getting from one form to another represents
the major implementation problem. Performing transforma¬
tions on the intermediate forms to simplify the remaining
tasks or improve the quality of the resulting machine code
may be a subsidiary task. The overall data flow for an
elaborate compiler is given in Figure 4.1. The remainder of this
article is devoted to explaining the meaning of the various
algorithms and data structures depicted in the figure.
5. Transformation on the Token String
The problem of translating a very complex language (e.g.,
the IBM PL/1) can be simplified by passing repeatedly over
the token string, each time producing an equivalent token
string with fewer primitive concepts. The final set of primitives
is usually taken to include GOTO, IF, assignments and other
things that map directly onto a conventional instruction set.
Table 5.1 displays three successive equivalence transforma¬
tions on a PL/1 program. Initially there is an array assignment
which implies a loop (stage 2). The translator has had to create
some new identifiers which are started with *$’ to avoid con¬
fusion. The control expressions of the do-loop are evaluated
only once implying that the head of the loop contains only
simple variables (stage 3). The loop itself can then be factored
into IF and GOTO constructs (stage 4). The advantages are the
already mentioned reduction in overall translator complexity
and also the fragmentation of the translator to aid in making
each piece small enough to permit running in a small memory.
It has some utility in documenting the meaning of language
constructs where the transformations are simple enough to be
easily understood.
The technique has some disadvantages. It can be slow since
repeated passes over the token string are required. Clever
methods of speeding things up may cancel the gain in simpli¬
city that led to its use in the first place. There is also a lack of
theory governing the transformations, leaving a potentially
confusing series of ad-hoc algorithms. Finally, the transforma¬
tions may obscure relations that would have been useful to the
generators. For instance, the fact that the example in Table 5.1
can be accomplished with a single memory to memory block
transfer instruction will never be recovered from the Simpli¬
fied” form at stage 4.
Page 10
204
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
records
character string
token string
simplified
token string
phrase-
structure tree
simplified
computation tree
language-specific
sequential code
optimized
language-specific
sequential code
machine specific
sequential code
optimized
machine code
records
source text
_ 1 _
input record handler
phases
-M.
parser
phases
generator
phases
emitter
phases
output record handler
executable program
translator control information
program listing
lexical error messages
string table
equivalence transformations
on the token string
syntax error messages
symbol table
undefined symbol messages
equivalence transformations
on the tree
semantic error messages
equivalence transformations
on the language-specific code
equivalence transformations
on the machine code
assembly listing
Figure 4.1
An Elaborate Compiler
DECLARE (A, B) (20) FIXED;
A=B;
DECLARE (A, B) (20) FIXED;
DECLARE SI1 FIXED;
DO $11 = LBOUND(A) TO HBOUND(A);
A($I1) = B($I1);
END;
DECLARE'(A,B"J (20) FIXED;
DECLARE ($11. $12. $13. $14) FIXED;
$l2 = LBOUND(A);
$13=1
$l4=HBOUND(A);
DO $11 =$12 BY $13 TO $14;
A($I1) = B($I1);
END;
DECLARE _ (A, B) (20) FIXED;
DECLARE ($11. $12, $13, $14) FIXED;
$12 = LBOUND(A);
$13=1;
$l4=HBOUND(A);
$11 =$ 12 ;
1 = 1 ;
DO FOREVER;
IF I > HBOUND(A, 1) THEN RETURN;
A(I, J) = B(I, J) + (I + 1) *3/J;
1 = 1 + 1 ;
END
Figure 6.1
A Source Text
$15 = IF $11 > $12 THEN GO TO $16;
A($I1) = B($I1);
$I1=$I1 + 1;
GO TO $15;
$16:
Table 5.1
Successive Transformations of a PL/I Program Fragment
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
205
Figure 6.2
Phrase-structure Tree for Text in Figure 6.1
STATEMENT LIST
GROUP
T
GROUP HEAD STATEMENT LIST ENDING
STATEMENT' STATEMENT
A
ASSIGNMENT ;
VARIABLE = EXPRESSION
/ /
^ID ^TERM DCT FOREVER ; STATEMENT STATEMENT ST^fEMENT END
I PRIMARY IF CLAUSE STATEMENT ASSIGNMENT'; ASSIGNMENT';
A /\ /A
^CONSTANT IF CONDITION THEN RETURN ;yy \ VARIABLE = ^EXPRESSION
1 EXPRESS iSN^EX^RESS ION VARIABLE = EXPRESSION ID EXPRESSION^TERM
/ / '
TERM TERM IDT ( SUBSCRIPTS )
PRIMARY PRIMARY A EXPRESSION , EXPRESSION
/ I \ \
VARIABLE FUNCTION TERM TERM
I \ |
ID ID ( PARAMETERS ) PRIMARY PRIMARY
I / ^
I HBOUND EXPRESSION--, EXPRESSION
/ /
TERM TERM
/ /
PRIMARY PRIMARY
/ /
VARIABLE CONSTANT
/ /
I
VARIABLE
TERM
PRIMARY
I
VARIABLE
PRIMARY
I
CONSTANT
I
1
ID
I
I
ID
/
VARIABLE EXPRESSION + TERM
/ I /
ID ID TERM TERM / PRIMARY
I i / \
I J PRIMARY TERM * PRIMARY VARIABLE
/ / \ \
VAR IAB LE ^PRIMARY^CONSTANT ID
ID ( SUBSCRIPTS ) ( EXPRESSION ) 3 J
/
B EXPRESSION', EXPRESSION EXPRESSION + TERM
/
TERM
/
PRIMARY
/
VARIABLE
/
ID
I
TERM
!
PRIMARY
I
VARIABLE
I
ID
I
J
\
PRIMARY
\
CONSTANT
\
1
Page 12
206
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
6. Transformation on the Computation Tree
Figure 6.3
For a given program (Figure 6.1) the recognizer can auto¬
matically compute the phrase-Structure tree (Figure 6.2), Computation Tree from Figure 6.2
which can then be reduced to a computation tree by renaming
that call for no operation. The computation tree (Figure
6.3) then constitutes a data structure with an interpretation
that is invariant under certain transformations. Both reducing
the number of primitives (simplification) and improving the
code efficiency (optimization) are useful goals. In the
example, the concepts of pre-evaluating constant
subexpressions and linearizing integer multiplication are
illustrated. The reader should be aware that there are many
other useful transformations. Frank DeRemer calls the tree
in Figure 6.3 the abstract syntax tree. The transformation
from phase-structure tree to abstract syntax tree can be
formalized to the point of allowing the compiler writer to
specify it in tabular form, thus avoiding the rather messy
task of manipulating the tree directly.
The loop has an induction variable (I) which is stepped
by a constant amount (1). This fact, discovered by examina¬
tion of the computation tree, allows multiplication by a
constant (or unchanging variable) to be turned into addition.
The generally slower execution time of multiplication together
with common subscript algorithms which imply a fixed-point
multiplication means that there is considerable to be gained.
Figures 6.4 through 6.13 depict subsequent stages of the
computation tree as the various phases of the transformations
are carried out. Each figure should be compared with an earlier
figure (usually Figure 6.3) to get a before/after view of the
transformation being illustrated.
In Figure 6.4, the array A, having declared elsewhere to
have an upper bound of 8, yields a constant for the function
HBOUND. In Figure 6.5, the double subscripts are turned
into simple single subscripts with polynomial values. The
multiplication of an induction variable is linearized by creating
a new induction variable ($12) which is stepped by the multi¬
plier (Figure 6.7). Then addition of constants are twice pushed
off onto the new induction variable (Figures 6.8 and 6.9).
Then the use of the variable I directly after it has been set to
a constant value allows some pre-evaluation (Figure 6.10).
Finally, the remaining multiplication by a constant is pushed
out to the leaves of the computation tree (Figure 6.11) so that
it too can be linearized (Figure 6.12). The resulting tree is
displayed in Figure 6.13.
Tree transformations consume more computational
Resources than most other phases of translation both because
the tree occupies a lot of memory and also following the
link takes a lot of time. Thus the implementor must be careful
in deciding which transformations are economically justified.
Tree transformations are easier to carry out when the source
language does not include a GO TO construct to break up
sequences of code, thereby making difficult the detection
of induction variables and the like.
B I J
J
ADD 3
/\
I 1
Figure 6.4
Pre-evaluating Constant Subexpressions
/
GT
I 8
Figure 6.5
Replacing Double Subscripts with a Single Polynomial
Sl|B^ J
MUL 8
A
t 8
Figure 6.6
Combining Common Subexpressions
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
207
Figure 6.7
Linearizing an Integer Multiplication
PEAT
Figure 6.10
Pre-evaluating Constant Subexpressions
STORE
SEQ
IF STORE STORE STORE STORE
SJQ
REPEAT
STORE
r\
$11 ADD
0 J
ST£RE
$11 J
Figure 6.8
Removing Linear Terms from a Loop
Figure 6.11
Pre-multiplying by a Constant
DlV
/\
A^D J
MUL 3
A
I 3
IF STORE STORE STORE STORE
/\
$11 ADD
/\
$12 J
SEQ
STORE STORE
A /\
$12 ADD
/X
^UB J
MUL 8
I 8
-42-
Figure 6.12
Linearizing an Integer Multiplication
Figure 6.9
Combining Variables with a Common Value
Figure 6.13
Computation Tree After Simplification and Optimization
STORE' STORE
A N
ii $n j
REPEAT
and delete STORE
$U / ^Al2
IF STORE STORE
A\ A /\ /\
GT RETURN SUBS ADD I ADD $11 ADD
A A T\ A
I 8 A $11 SUBS DIV I 1
N W
B $11 $13 J
STORE
/\
$13 ADD
l\ /\
$11 8 $13 3
Page 14
208
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
7. Transformations on Lanuguage-Specific
Sequential Code
The computation tree yields the language-specific sequential
code partly by resort to zero-address code (a left-to-right
sweep of the tree) and partly by insertion of transfer
instructions where implied by the tree (IF, THEN, ELSE,
loop, procedure calls, etc.). The transfers can either be conven¬
tional branches or more restricted transfers corresponding to
CASE, CALL, RETURN, REPEAT, etc. Such a code for the
tree in Figure 6.13 is given in Figure 7.1.
Most of the transformations that can be carried out on the
computation tree can also be carried out on the language-
specific sequential code [Allen 71, Cocke & Schwartz 70]. In
addition, the branching structure itself is open to some optimi¬
zations (e.g. if the destination of a branch instruction is an
unconditional branch, the first branch can be reformulated to
go directly to its ultimate destination).
8. Transformations on Machine Code
The translator emits machine code by passing over the
language-specific code with a simulated language-specific
machine which, instead of evaluating, emits code (Table 8.1).
Figure 8.1 displays several stages of the stack during the
execution of such an algorithm [McKeeman et al 70].
Table 8.1
Source Text and Language-specific Code
X=X+1; If X < 3 THEN GO TO L;
LIT X; LIT X; LOAD; LIT 1; ADD; STORE;
LIT X; LOAD; LIT 3; LT; LIT $L1; BRANCH_FALSE;
LIT L; BRANCH; $L1: ...
Most computers have peculiarities that are utilized by
assembly language programmers but are not directly available
to the compiler, partly because the opportunities to make use
of them do not become apparent until after the machine code
itself has been emitted, and partly because they are special
to the target machine in question [McKeeman 65]. Table 8.2
shows a typical situation of this kind. At stage 1 we have a
good machine code for the two statements. Because addition
is commutative, the addresses of a pair, LOAD ADD, can be
interchanged (stage 2) which permits the slow LOAD = 1 to be
replaced with a fast load immediate LI 1 and also saves the cell
containing the constant 1 (stage 3). In any pair, STORE X
LOAD X, the LOAD can be dropped if it is not the destination
of a branch (stage 4). Any pair of branches, where the first
is a conditional skip and the second is unconditional can be
reduced to a single conditional branch (stage 5). Finally, on
a machine with an add-one-to-memory instruction, the
sequence LI 1, ADD X, STORE X can be combined into one
instruction (stage 6).
Table 8.2
Transformations on Machine Code
LOAD X
ADD =1
STORE \
Stage 1 LOAD X
LT - 5
BRANCH 1 A! Si: $L1
BRANCH' 1.
$L1:
LOAD =1
ADD X
STORE X
Stage 2 LOAD X
LT =3
BRANCIM AI SH $L1
BRANCH 1.
$ LI:
Figure 7.1
Sequential Form of Figure 6.13
LIT 1; LIT 1; STORE; LIT $11; LIT J; LOAD; STORE; LIT $13;
LIT 6; STORE; LIT $14; CALL...
$14: LIT I; LOAD; LIT 8; GT; LIT $15; BRANCM_FALSE; RETURN;
$15: LIT A; LIT $11; LOAD; ADD; LIT B; LIT $11; LOAD; ADD;
LOAD; LIT $13; LOAD; LIT J; LOAD; DIV; ADD; STORE; LIT I;
LIT I; LOAD; LIT 1; ADD; STORE; LIT $11; LIT $11; LOAD;
LIT 8; ADD; STORE; LIT $13; LIT $13; LOAD; LIT 3; ADD; STORE;
LIT $14; REPEAT;
Figure
8.1
An
Eir.i 11 c r
Turning Zeiv-aildress Code into S
ingle-address
Code
Stack
LlJ
i x 1
LlJ
111
1 ,
| X | 1 X
Zcro-Addrcss
LIT X
LIT X
LOAD LIT 1
ADD
STORE
Single-address
LOAD X
ADD =1
STORE
X
Stack
Zero-address
LIT X
kJ
Lid
LOAD
ill
LIT 3 LT
i 1 ,L1
1 0 j i a
LIT $L1"
1
BRANCH
FALSE
Single-address
LOAD X
LT =3
BRANCH^
FALSE SL1
Stack
Zero-address
LIT L
Ll)
u
BRANCH
$L1:
Single-address
BRANQI L
$ Ll:
Note: ° represents a value
in the accumulator
Stage 3
Stage 4
Stage 5
Stage 6
LI 1
ADD X
STORE X
LOAD X
LT =3
BRANCIIJ-ALSE $L1
BRANCH I.
$L1:
LI 1
ADD X
STORE X
LT =3
BRANCH_FAI.SE $L1
BRANCH L
$L1:
LI 1
ADD X
STORE X
LT =3
BRANQI TRUE
INDEX X
LT =3
BRANQI TRUE L
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
209
Innumerable ingenuities can be applied. Since the savings
can be dramatic (as in the example), the technique is useful
and popular. Nothing makes the hero-author of a compiler
happier than producing really subtle correct code, beating
the assembly programmer at his own game. One must,
however, guard against introducing errors into the code as
a result of not carefully considering the conditions under
which the transformations leave the program invariant.
9. Fragmentation Planes in the Translator
There are many reasons to want to break a compiler into
pieces. The ability to run the translator in a small memory
is one which the computer salesman and computer purchaser
feel is important. The problem of managing large
programming projects has demanded a task organization
which results in many small well-defined subtasks. Further,
there seems to be a definite limit on how complex a task can
be attempted without incurring exponentially growing delays
and costs. There even seems to be a critical size beyond which
repairing an error introduces on the average of more than one
error. And, finally, no matter how well a system seems to
perform, it is good engineering practice to know how well and
under what range of conditions the system will perform. Such
knowledge comes from understanding; understanding comes
from not having to consider something complex all in one
mental step.
There are some principles that guide the choice of natural
boundaries between program modules. A boundary is good if
there are a few references across it into other modules and
those references are relatively infrequently exercised. A
boundary is good if the information flow through it can be
simply described. A module is good if its function can be
simply described. A data flow is good if it can be totally
produced before any of it is consumed (meaning no feedback
is needed across the boundary). A set of modules is good if
execution activity can be isolated in small subsets (working
sets) over substantial spans of time. And such a set is well-
designed if particular dependencies are isolated in small
subsets (e.g. target language does not appear until the very
MIND’S EYE SOFTWARE
News Release Received: 78 April 5
Mind’s Eye Personal Software produces and distributes soft¬
ware for the personal and hobbyist computer user. Initially,
this consists of cassette tapes for the Commodore PET Person¬
al Computer.
Mind’s Eye will sell tapes either on a direct mail-order
basis, or at a quantity discount rate for resale by other vendors.
The direct mail price will be approximately 10% less than the
suggested retail price for the other vendors.
A Catalog will be available soon which will list and describe
the programs available from Mind’s Eye. We hope, as we grow,
to offer an extremely large variety of programs for your
perusal. The Catalog will also contain many other things of
interest, such as royalty policies, expected programming stan¬
dards, and a section of advertisements by vendors of PET
related hardware.
To attract a variety of programs and to assure their quality,
royalties in the range of 10-20% of the RETAIL price of the
software will be offered. Submitted programs will be checked
and “editorial” suggestions made to the authors to maintain a
high level of reliability and creativity. Authors who are willing
to make suggested changes will receive higher royalties as a
result.
As this is a Personal software company, please do not hesi¬
tate to send programs which you feel may be of limited
last stages in Figure 4.1). It is also of value if one module
can be changed without involving the processing of many
other modules. We can suppress detail by considering a subset
of the modules as a single module where the internal data
transactions and control transfers are ignored. The boundary
around such a supermodule is good if the resulting module
obeys the rules above.
The techniques of engineering programs are being
developed. One of them is modular programming which,
when applied to translators, depends upon the organization
of the translator (e.g. Table 4.1) and upon the application of
the principles above. The time should soon come when
translators are well-engineered as a rule, not as an exception.
REFERENCES
Allen, Frances E„ "A Basis for Program Optimization,” Computer
Software, IFIP (1971), page 64.
Cocke, J. and Schwartz J.T., "Programming Languages and their
Compilers (preliminary notes)", Courant Institute of Mathematical
Sciences, N.Y.U., N.Y. (April 1970).
DeRemer, F.L., Practical Translators for LR(k) Languages, Ph.D.
dissertation, M.l.T. (September 1969).
Dijkstra, E.W., Notes on Structured Programming, Report 241,
Technische, Hogeschool Eindhoven (1969).
Gries, D., Compiler Construction for Digital Computers, John Wiley
& Sons (1971).
Lehman, M. & Belady, L., "Programming System Dynamics..."
IBM Research RC3546 (September 17, 1971).
McClure, R.M., "An Appraisal of Compiler Technology," Proc. SJCC
(1972) page 1-9.
McKeeman, W.M., Horning, JJ. & Wortman, D.B., A Compiler
Generator, Prentice Hall (1970).
McKeeman, W.M., "Peephole Optimization," Comm. ACM 8, 7 page
443 (July 1965).
Parnas, D.L., "Information Distribution Aspects of Design Method¬
ology," Computer Software, IFIP (1971) page 26.
Rohl, J.S., "A Note on Backus-Naur Form," Computer Journal,
Vol. 10, pages 336-337 (1967-68).
interest. Mind’s Eye has carefully considered the problem of
low-volume sales of individual programs, and has designed its
facilities to be capable of handling low-volume programs
profitably.
Mind’s Eye is especially interested in programs which
1) solve a particular problem that you have had, 2) educational
items, including ones which are “trivial”, 3) programs depen¬
dent on the PET operating system, 4) machine language
programs, 5) useful utilities, and naturally, 6) games and
amusements. Contact P.O. Box 354, Palo Alto, CA 94301;
(415)326-4039.
FLOPPY CONTROLLER USES
NEW MOTOROLA CHIP
News Release Received: 78 Mar 13
WINTER Corp. has incorporated the new Motorola MCM
6843 floppy disk controller IC into a low cost floppy disk
controller. The 4 Vt” x 6'A” module interfaces to any full size
or mini floppy disk drive. The module supports both hard
and soft sectoring, IBM 3740 or user programmable read/write
format, automatic CRC generation/checking, and
programmable step and setting times. $199.00 unit price.
WINTER Corp., 902 N. 9th Street, Lafayette, IN 47904;
(317) 742-6802.
Page 16
210
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
SOME ADDITIONS TO LICHEN WANG'S ROBOT CONTROL LANGUAGE
BY KEN ANDERSON
KEA Microdesign
P.O. Box 6531 Stn. A
Toronto, Canada M5W/X4
Dear Jim: Received: 78 Mar 24
Enclosed is a program listing of ‘Yet Another Body’ for
Lichen Wang’s Tiny Robot Language. In this body, the
VDM/Sol display is shared to map robot movement during
the ‘Body Mode’ as well as display mind contents during the
‘Mind Mode’. Please note that a graphics density of 128 x 48
cells is accomplished on the VDM/Sol display by addition of a
‘GraphicAdd’ piggyback board. This program is easily convert¬
ed for Poly/SSM type displays by modification of the cell
mask table (see listing).
Ken Anderson
For a full description of the TINMAN language, also known
as WSFN, and 8080 source listing, see DDJ Volume 2, Issue 8,
pp. 8-19 ‘An Interactive Programming Language for Control
of Robots’. Hardware requirements are a Sol or VDM display
equipped with GraphicAdd graphics board, an ASCII key¬
board and an 8080 system with 8K of RAM at 0-1FFF. On
initial startup of WSFN, the computer asks ‘Are my graphics
software-selectable?’ Keying ‘Y’ will enable the GraphicAdd
graphics for this and subsequent re-entries to WSFN. Then the
‘Mind Mode’ is entered. If valid mind contents exist at 1C00
in RAM (see the Mind, below), the mind is displayed—if not,
then the mind is first brainwashed. This feature allows
previous ‘memories’ to be reloaded from mass storage before
re-entry to WSFN.
The Mind
This is functionally identical to Lichen Wang’s description.
However, this mind is located in RAM at 1C00-1FFF. After
every keypress, the ‘Mind Mode’ is entered, and the VDM is
updated with the latest mind contents. Thus, during all mind
operations, the display appears as described in DDJ. A few
more commands have been added for convenience:
ESC (IB hex) Exits to Monitor
CTL B (02 hex) Brainwashes the mind for a fresh start
; is translated to + to save wear on the shift key
*- (01 hex) back-arrow backs up cursor to correct typos
NOTE—does not move over brackets.
Yet Another Body
The graphics capability of 128 x 48 bit-mapped cells is
used for tracing robot movement. The display is arranged to
Sol with GraphicAdd demonstrating ROBOT program. A mix of Body
and Mind modes was arranged by: Z to initialize movement
then b to dump Mind on display
then E to map movement without
first clearing display (i.e.. Mind)
‘wrap-around’ movements that go beyond screen limits.
‘Body Mode’ is entered whenever a body command is exe¬
cuted. This mode is maintained until the next keypress, which
returns to ‘Mind Mode’.
Body commands are identical to those previously described
in DDJ.
One additional command is:
S Switch trace—the trace is left as per definition W or B
until it crosses over itself—then the intersection is switched
B/W or W/B. This command allows complicated patterns to
develop without eventual ‘white-out’ of the display.
Number 25
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 17
Robot Command Summary
MIND
N
Face North (up)
W
Leave White trace
(space)
No operation
B
Leave Black trace
+ (or;)
Increment accumulator
S
Switch trace state on overlaps
—
Decrement accumulator
C
Clear screen (to B or W)
A
Current value of accumulator
T <then><else>
Test if A>0 : then <then>
Examples:
if A = 0 : then <else>
1. Windmill
? <then><else>
Randomly choose <then> or <else>
DX (CA
. -8 (HNARP +))
D <char><commands>Define <character> to
DP (...
..) where P is a curve
be <commands>
X
draws a windmill
NOTE: recursive macros are allowed!
n <command>
repeat <command> n times
2. Spiral
where n = integer or A: current value
DGF
step length
DM (HN 23 F CA(AG —2R))
EDITING
A-
zero accumulator
50+
set A = 50
DEL
Erase line
M
draws a spiral
<-(or CTL A)
Erase character, but not brackets
CTLB
Brainwash mind
3. Hilbert Curve
ESC
Escape to monitor
DUT (-
V G 6R U 2R G U G 6R V +) 6R
DVT (-
U 2R G V G 6R V 2R G U +) 2R
BODY
DG4F
DZ (HN 23F 2R 63F C F 2R U)
F
Move Forward one grid cell
A-
H
Go Home to center screen
5+
set A = 5
R
Rotate 45 degrees clockwise
Z
draw curve
ooooooooooooo
-iMr\<iiAvor'coa'0'HN'^
000000000—1—1^ —
ooooooooooooo
oooooooooooo
<riA'or^coo'a'’Ni^<iio
—• •—I —1 •—ICSICSJCNO'JCSICN
oooooooooooo
ooooooooooooo
vOI^Q^O — CN'^<J'A-i)^aD
ooooooooooooo
oooooooooooo
o\o-<(M^<iir\\or^covo
^<j<r<r<r<j<r<r<r<j<rLT'
oooooooooooo
ooooooooooooo
HNr\<riAvor'COO'OH(Mn
lAiAiAiAiAiAiAiAiTi'il'fl'O'O
OOOOOOOOOOOOO
a C <CO CD CNl CD CSI CD <N| —1 CSI O f'N
O CJ C_> C_J — O —1 O U.OOOOO
O CJ CD CJ (N f'N -t U UL. < O' U- U. sO CJs CO <T CMOCvJCMf^»tMOr r \r^if^
O C_) O — OOO U. U. CJ U. Q CJ CD <T Q O' r*-\ OljOOOOOOOO
HLJUJN'OnUUCN^ — Li_ KS O — QO —' Q Q O C r^\ <T ^<[D-i[0<uj' , "OUNQNO'NCDI N U^<
N^U-U^NMi-UU l^<QU ^ C_) O CSI CJ U CJ U CJ — <ri'-HO<rLO^O<J<J^OsOO<JrliAOir\N
OOK\'?'00'CQCJQL.NiAiAiriir»Q^vJ\fJ(^^M^'0lsQKMnoiamu-'CDuC00'0'0N^CJQL.ONl , i/\'0Q^inULJU.'HN<JiMsC0<<£<
OOOOOOOOOO — — — — —iOOOOONNi/'in'/\SMMMMJ'a'<<<(jLHJtJU'/'iAiA'C'0'fl'0'C'0'0'0'0'0'0SNNMsr'M— I—
0<<<<<<<<<<<<<<OQQOOQQOOOOOOOOOOOQQOUOaONNNNNNNNNMNNNN(MNNNNNNNN
ocjc_)Ljcjc_)CJCJcjcjc_)c_)CJc_)C_)oooaooooooooooooooooooooooaooooooooooooooooaoooo
Page 18
212
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
d
o
CO
in
X
eta
Q
O
UJ
QC
(_)
in
cr
c_)
to
- o
X d I 2 Q X
x—*xrsixxh-
2 >• X 2 X X X
Miuncuict;
Q- Q
N U 2
cr —.
•- X
uj ~
in in t—
UJ UJ UJ
a: >- in
- - ^ < < x
XX • C_)
< o d ►
: •- x :
inz ►
O P" H-.
x in
a_ —
C 2
CC □ O
X
in .
Q- •— C_> d
x a: m u m >
in uj y in 1
■t s in - a. in
-in -in d *-<
2 d 2 ;
O 5
in 2
d —
3 d
3 in x (
J -— or 1 — t—
: o in □ ;
: in uj m c
XX -c
< in >- z :
: in in o: m
- C_) d o d
: 1 — 1 H- I 1 — c
: 1 > uj u 1
) o_ cd x a: :
d 1
. cc in o in <
h o uj i-h >-* :
)inir<i-«
: u u > m <
) X 2 C
: cd uj d 2 c
- x j— o c in - uj
jo a- mhh iqc x
3 in in >-2 - in a - x
:xcx - •-< d a t— oinot
'<< MNHH -H JCXNQ.
jQocrvja.2:>'XQ:xx<iox2x
iooooxoo_ixc-x xqcp-)
j u_ x in 2 -h
vc
cc 3
o cc
- o
x m x
x Q
—> d in *-> x o_ *—
XXXOUI
cc x in a_1 in a_ cc
xxxxxxxxxxxxxxxxx
Ni , N-3iri'flNa)0'0-HNi^^ir\yoMoO'OHNi , i>jin'Or^
' - - - ■ inmm'C'OvO'Ovovo'O'O'O'or'r'r^i^i^r'r^N
-XI CD CM
xxjxxxxxxxxxxxxxxxxxxx
His^<nnx^co^OHMr<jin c cd c
CDCQCOCDC 0 ajDCDCC 0 '^O' 0 ' 0 \C'CMM>^CQ
o a o o
N 1 ^ <J lA
OOOO
CM CM CM CM
oooooaooo
XMDD'QHNn<f
oooa—(—1—•—1—i
CMCMCMCMCMCMCMCMCM
CM
O
r*'
o
K-\
O
X
X
CM
X
CM
X
X
X
X u
CM X
d r-, uLom co cm
U. X U h- U CM CQ
<J (Ml X U U_ d
cd m in u h l co i*'
X CM M3 CM
OX X d
U_ CM VO CM
X CD CD d
r*"\ X X CM •—1 —1 O'
N m CD L) Q U (J
COX'OCDm'OxCMr^XCMO'
OlMuJUDuLUDminu
< I s ij u im uj in
f'n CO X X X K 3 Q
•—> d on o m x p^\
HCMHMDUU
icuNinniMHin
ummujcMCMuju
CDUJlMiTiHCM-iO'
u m n uj cm cm uj o
U. Q (M m nO I s x
O Q Q a Q Q Q
CM CM CM CM CM CM CM
X X X X X X X
O'. O' O' S' S' cc u
x o a x x a Q
CM CM CM CM CM CM CM
X X X X X X X
uj u 1-1 m n x
qOuuuju
CM CM CM CM CM CM
X X X X X X
O' CQ X X X X X
1 . 1 1 ■ 1 1. 1 1 ■ 1 1. 1 1.1 1 ■ 1
CM CM CM CM CM CM CM
X X X X X X X
u.u_u_u_u.u.cMf^'nxmou.u.cMir\'nr'XosooooOLi.cMi-nvooN<mamm
XXXXXXXXXXX XXX X X XXXXXXXOXX —M •—1 •—i •—t 1 —( •—1 1 —( r—t
iMCMCMCMCMCMNCMCMCMCMNCMiMinininininininmminr. inrinin^mmininm
XXOOXXXXXXXXXOXXXXXXXXXXXXOXXOXXXXX
X X
r-i CM
CM CM
X X
cACDO'ddddCDX
CM CM CM CM CM CM CM CM CM
innnnninrNinn
xxxxxxxxx
xxdxxxxx
<r m
X C. X o
d X
J CSI O d -
d o
<-1 - - X
cc x -j o :
x o x o < a a
ID—<>—!•—lXQ_(MIQ_P
CM X X > > 2 X 2 X L
era_ixx—*oxo.c
muiMi
>m x x x :
ecu a_1 r
< < o: < 1
cm o: *— 2 1— 1
qc x in •—1 in i
x Q —1 _j
in_j>x_i>>-m—1>>
IMXXXQdXCJXdXX
QC Q- ix<toxxinoxx
—JQ_>— >—INICHMIEI
XXUJQ-2 X C_ 2 2 l
innicunQucH!
CL I- Q CD
X X 2 -
X X —
c cr x o
O-JQQ X X U_ X X— —. CM
***000 * * * X * * * 2 * * * CE X X
IXXXXXXXXXXXXXXOXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXX
'i/N'Or'COff'X'iCMin'Cir\'OMDo\Xi-iiMin<jinvOMDO'OHNin<fin'OMDinxHNnvrinioi^caiJ'Q^cMfn<riruor'iao'QHr-' —■ - — - - -- ■— ■— - • -- - ~ - — ~
)'0'0'0'0'or'-r^r^.r-r-r^r'-r^r^''-cocQ3oc3oa3a3cococDc»0'0'0'0'0'0'0'a'0'C'XxxxxxxxxX'— — — 1 — 1 — — 1 — 1 .
1 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX—I —1 — —< —. — —1—IH-< r-* ^ .
o
o
CM
X
XXX r-H
X Q CM CO
X M 3
<* M 3
<J <J UJ CM <
CD CD U_ X CD
CDiniHUJ'OinuCMHD'
O UJ CM KN 1 *"' CM CD O Uj O
cd in in h m
O UJ a CM o
CO U_ CM X CM O'
X <t 1^1 f'N O
coincxmQu. xunor^-O'C'-j—lO'ujcMQujaxo'
UUCMMOX'JMMJ'O'ONUU'U.Uinii.Linu
< MO n in
maxuCi
d c d <c d x o
1— r- 1-. r'- r-^
CM CM CM CM CM CM CM
X X O O X X X
u_ -h <r m co
C'' CD CO CD CO CO
CM CM CM CM CM CM
X X X X X X
O' d C d d CD X
CD CD CD X X X X
CM CM CM CM CM CM CM
X X X X X X X
q x m m m n <j
X O' O' O' O' O' O'
CM CM CM CM CM CM CM
X X X X X X X
lT\ X O' X O O
O' O' O' O' O' O'
CM CM CM CM CM CM
X X X X X X
QQUU.CMn
O' ff> O' O' < <
CM CM CM CM CM CM
X X X X X X
■o co O' d x uj
d d d d d d d
CM CM CM CM CM CM CM
X X X X X X X
L.(Mn<J'DO'doDl _I X X X X
dmxmxxxxxxxaxaxx
CM CM CM CM CM CM CM CM CM CM CM CM CM C J CM CM
xxxxxxxxxxaxcxxx
U_XXXCMP'''<fJ'i
JDCDCDCDXXXX
CM CM CM CM CM CM CM CM
xxxxaxxx
M 3 O' X X X
X X X X X
CM CM CM CM CM
X X X X X
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 19
213
Uj u y uj < o: _i
> uun u Z o Q-
—I z z
CO — •—
< x p— o
in i— X o.
OGQ Ul
a. z a; > oi
in ui ce l_j
— —) X •— cr
Q in z o
U < U Q
U1U2 <
- < Z Ifl
in /— o o
u in < _i z
inuco-
x x cd in x
_iino
CJ O O
cr cr cr
u<<
in o o
CD CD
_!>->-
O U id
in y y
cr o
< (_i
x o x
CJ - UJ
O < O £
O < X CO O X U O hcd M •
O O j
CL Q a o
in u in in
cjxocjoxxocj:
—i x a
o o o x x x x
oqiuuu<u
3 UUUUUy U.L
NOnO—I.-IOOOOO
<<Q-<<<a-a_a_p— I— X
3 Q QC O I— 0C ►— OOOU Q-CQCDCDCDCDCDCDCD
3_jozinxina-Q-a_crin<ooaooooo
*-> cr.
*£ •— CJ 00000300000
LkJ ^^*^^2SCD2XiiSXXiXiXQ:incDCDCDCDCJCyoC3C500'0000
"OOCjr-jinarOOOOOOOOOOOOOOOOOOOoOOOOOUJUJUJLLJUujLJuiUJUJlLj
CD
• in
X X >
ooooooooooaoaoooooooaoocooc
HNK\<lft\OMSO'OHNr^<fiA^MOO'0'HN^< m NO r
0'0'0'0'(7'CT'0'0'0'0000000000<—<■—<■—<-^<- ~-< —■< -
NNNNNCMNNIN^^r^r^KNKM^^r^f^l^l^KM^f l<M<
< u z o in •
*— ui x >< in<t :
ininxs-OQQXii
• cr cr :
: c_i cj £
i in in :
) o o o
)HNI^
J CSJ CM CM
\ m m
ooooooooooooooooooooooooooo
<JiANOr'-cOONO-HCMPn<inNOf'sC3CyNO—PCMPAsTiAvOrscOCTNO
CMCMCMCMCMCMPnmPnpnpnpnpnPnpnfn<T<T<T<r<J<J<J<T<J<TiAin
-- ----- -
'-< «•-< i>» i-M r", m m r-A r~\ m m pa pa <j <j . 3 -
0000
CM PA <J lA
in in in in
pa pa m pa
O O O O (
VO MO OM
in in in lA '
in in pa pa r
) o o o o o
< CM PA <J lA NO
) NO VO NO 'O 'O
' PA fA PA rA PA
U 0-1 VO
I s O Q N
<Qya-<NA<T
CTNONON<<<<<
lAlAIAlAIA'ArA'A
00000000
lA CO Us <C CD l—J
<C<T<<C<C<
fA PA PA IA PA PA
a o o o o o
u u Q U U.
< < < < <
PA PA PA PA PA
o a o o o
0000c 000
f" <
CD CD
PA PA
o o
O U- O —< CSI PA
CD CD CJ CJ CJ CJ
PA PA PA PA PA PA
000000
PA CM PA PA
0000
u_o\r^pA cm o on rs —< co pa pavonnoiAia<3niao
CD Q U CD iA CM in <T <T <T <J 1 A<J 1 A 1 ACSI<J<J 1 A<T<TCSI
2NQ<NffvHiAQONOCMAQU.<rHi/\IA(JIAriUU.
3C_)C_)CJPAO<f<J<CSIiAiA<JiACSI<TiA<T<IiA<J<J<T<TPA OOOO
<rr^<oo-MPAiAr^ONCDOu.ocM<NOco<c_)UJocM<jvo<c_)OuJu.ooooooooooo
CJCJCJCJOOOOOOOOQUJUJUJUJUJUJUJUJU-Li_U_U.U_U.U.U.U.OOOOOOOOOOO
PA PA PA PA PA PA PA PA PA PA PA PA PA pa PA PA PA PA PA PA PA PA PA PA PA CD CD CD CD CQ U (J CJ CJ CJ CJ CJ CJ CJ C_) CJ
ooooooooooooooooooooooooo-
cr a.
O o
C_l 1C
o uj
CD PSI
o —>
CC O Z
O CC UJ
000
000
0 <
> cr
o o
X z
p— > p— cr in
Ul < UJ o <
o in in x X
1 in <000-
< rsi —1 < x < —< p-i p— < :
.iix-uQQ.Na.Nui—;
;nzinojununcri/)i
—I X < X
x - U. - •>
O < Ul 1 _I < c
CDCJOCJCJ<_lXXXXXXXCD QUQ
X X O CJ O Q
ininJXJ>QH>>QH(iuQQ>j-.iijuj»<mM.
jrMOOXCJXOOZOOO >ZZOOOX>OOOxX
ccro-ca-ixji<<xx<li/n<<zinzinina.
*- XX
x o < 00
- - •> 00
I CD U m Q O Q
ominw<ii:[DuQ>>>HQQQQQQ>a:M>Qi>ci:>jrtH>Q<MH
- '^^*' , ^^’0z0OOO><<<<<<O<>-O<C_)O<O<X>.o<0ZQ.
inr-)<XXXXOOOOOOXCrxXOxXcrx-“-_
««<PUJ uidCU. if o o
ooooooooooooooooooooooooooooooooocoooooooooooooooo
i^vO|sOOvOH(NPA^<AiONCOOvOHNPA<T<AvONCOOvOH(MPA<fiAvOrsaOvOH(S|A<JiAvOMIlOvO-iNPA<J
<-^<MCMCMCMCMCMCN|CMCMCMmfAPnmmfnpnPnmm<J<T<J < <J <J <T <<3 JlAlAiAiAJ'iAJViAiAiAvflvfWlJUd
M CM CM CM CM M CM CM CM CM CM CM CM A CNCMCNCMCMCN
-.-,-,-,^ 1 N i N i N W(N|(SINNCNINAAIAAn
CM CM CM CM CM CM CM CM CM CM CSI CS| CM CM CM CM CM CM CM CM
DOOOOOOOOOOC
si sj si muiui uv u^ lA lAiAiAiA'O'tJ'O'O'O'O'OvOvO'OlsNI— fs |—
CMrCMCMCMCMCMCMCMNCMNCMCMCMN--....... --
.-.i_<wi_.._»<_p<_ii_«i_ii_»i_(i_i<_»v_>i_iOOOOOOOOOOOOOO
CMPA4mvO|sfflONO-<NlA<IiAvOrsCOffvO'- ~
wu. w-iCMIASfiAvOMDOvQ
_ _ _ _ _ _ . AISA|S|S|S|S|S|SCOCOCOCO(IICOCDCOCDCOO'
CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM
<1 PA PA A* CM UJ PA PA lA
CM UJ CJ U. CJ PA <—I <-
U.CMPA<J <T <J<T'O^E3UQUQ'niACOO'<[D(jQUJLCMin^jr'(D<a]CJuaun<i/i\ju'UJUUUJ'l
CMPArAPAPAPAPAPAPAPAPAPAPA<J-0 < <T <J <f <J <J<J -O-OiAiAiAlAiAiAlAlAiAiT 'flvO'O'O'O'fl'fl'O'O'JS
PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA PA tA PA rA PA PA PA PA PA PA K PA PA PA PA PA PA PA IA PA PA —
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOC P—if— 11 —i i—i r-yr-v r-i i— 11—1 r— >
IN i-i ru- IN UJ PI n in -I b. M -in -i It Q CO vO O' O' I
O' QCOCD'OCMHO'(MjOCMOO'QCO<fl"OIMCMN
< ui < O' cm pa ov co in in < cd < O pa vo u. cj cm
CIU.UCJHHUCJUOCMUJCMIsCOUJ'OfsCO
U. CM PA vQ f*— CO < £□ CJ Q U O PA <J lA vQ O' CO LI Q Ul ■—I CM IA MB O' tf ff | I*) I ■ I
■ • s, s s, s. s. s. s. s, >,<JiAiAlAiAiAlAlAir\iAir'0'0'0'0'0'0'fl'0'0'0NNNNNNNNNNN
IA PA PA PA PA PA PA PA IA IA PA PA PA IA PA PA PA PA IA PA PA |f PA PA PA PA PA PA PA PApAPApAIApAPAIAPA PA PA PA PA PA
OOOOOOOOOOO
n co co co
PA PA PA PA
OOOO
A<fiANcoa'<a
PAPAPAPAPAPAPAPA
oooooooa
cjOui—< m<jiA'jco
COCDCOO'O'O'O'O'O'
PA PA PA PA PA PA PA PA PA
OOOOOOOOO
Page 20 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 25
214
FORTH
for Microcomputers
BY JOHN S. JAMES
1090 Miller Ave.
Berkeley, CA 94708
Forth is a unique threaded language ideally suited for
microcomputers. Programs are incredibly compact; e.g. in 5K
to 6K bytes you can get the interactive Forth compiler,
running stand-alone as its own operating system including I/O
drivers and other run-time routines, plus an assembler written
in Forth (in case you want to optimize time-critical programs),
virtual memory software, and a text editor. Not only does all
this fit into 5K to 6K bytes (of which 4K are written in Forth),
but it runs in the same space (plus IK buffer), with no
additional symbol table area, overlays, swapping, or use of any
other software.
And while Forth gives all the convenience of interactive
interpreters, it is very fast. For most applications, the run¬
time overhead is 20 to 30% for minis and 70 to 100% for
micros (compared to 1000% or more which is common for
interpreters). Number-crunching applications may take
longer. And when Forth isn’t fast enough, the system’s own
assembler can be used to re-code inner loops.
But the best news of all is that software development times
are cut by half or more over assembly programming. The pro¬
gramming is entirely structured (there is no GOTO), and the
resulting code is re-entrant and can be designed for PROM.
Forth has been implemented on many microcomputers. A
recommended configuration is 16K bytes and a terminal; a
floppy is a good idea for storing source programs (and virtual
memory for programs and data is supported). Forth works
well with a CRT, so hard copy is less necessary.
Forth has existed for several years, and is used commercially
in a number of installations, but until recently it has been
priced far out of reach of hobbyists, and even most computer
experts have never heard of it. However, the language is in the
public domain, and today low-cost versions are just becoming
available. Also there is a new Forth Interest Group (787 Old
County Rd, San Carlos, CA 94070), dedicated to letting the
serious hobbyist and the professional know about Forth and
how they can get it.
How it Works-Overview
Forth is very different from any other language in common
use. Perhaps the nearest is Lisp, which it resembles in one way
only: both are tree-structured languages which implement
themselves. Forth is an extensible, interactive language.
Forth starts with about 40 primitives, or operations defined
in machine language. New operations are defined in terms of
these. (So far this is like the virtual-machine systems often
used for implementing transportable languages—e.g.
Tiny BASIC, or P-code for Pascal. But in Forth, as soon as a
new operation is defined, it can be used in further definitions
or executed immediately, exactly as if it were a primitive).
There are no argument lists in Forth; instead, all routines
(operations) communicate through a stack. The programmer is
allowed to define variables, but in Forth, variables themselves
are operations which place addresses (or other values) onto the
stack—and which may use the full power of Forth or of
machine language to compute these addresses. This means that
users can create their own variable types.
Forth comes with about 140 routines already defined
(including the 40 primitives mentioned above). Programming
consists of defining new routines in terms of previously-defined
ones, until finally one of them is the whole program which is
desired. It then is executed by typing its name. Incidently, the
programmer does not need to know about all 140 operations,
because some of them are used mainly by the system. After
all, these 140 implement the compiler, text editor, assembler,
stand-alone operating system and run-time software, etc.
Execution is fast because at run time all definitions are
stored as strings of addresses; and it takes as little as two
instruction executions (e.g. on the PDP-11) to go from one
primitive to the next. Higher levels of nesting take a little
longer, but are done less often.
Debugging is exceptionally convenient because of the
modularity of programs. Almost any routine can be executed
by typing test-data arguments (which places their addresses or
values onto the stack), then typing the name; no driver
program is required. In practice, most Forth routines are very
short, no more than five lines of source code, often one line.
Each routine is checked out independently, then saved in an
application-oriented library for future use.
Blanks are the standard delimiters, so any string of non-
blank characters can be an operation name. Examples of actual
names are ‘ASSEMBLER’, ‘ELSE’, *!’, *(\ **’, ‘1 + ’. Even
numbers can be defined as operations. In one practical joke,
‘0’ was defined as seventeen. Operation names can be encryp¬
ted with embedded non-printing characters.
Example: A Small Program
Forth uses postfix notation like the Hewlett-Packard stack
calculators. This means that operands are written first,
followed by operators. E.g. ‘(A + B) * C’ in regular (infix)
notation becomes ‘A B + C * ’ in postfix. This expression is
executed as follows: place A onto the stack; place B onto the
stack; add the two values on top of the stack, destroying both
of them and placing their sum on the stack; place C onto the
stack; multiply the top two values on the stack, replacing them
by their product. Notice that there are no parentheses in post¬
fix. Also, Forth follows the convention of leaving the operands
in the same order as in the infix expression; this makes it easy
to remember the order of arguments for non-commutative
operations like subtraction. Another Forth convention is that
all operations should destroy all of their arguments on the stack.
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 21
215
Now let’s look at a complete Forth program. Assume that
the system is in the machine, but not any user programming.
The task is to write a routine to evaluate the polynomial
5X 2 -7X -10. The user types
: POLY DUP DUP * 5 * SWAP 7 * -10 - ;
This is the complete program. Let’s follow how it works in
detail.
The colon ‘’ is one of the Forth operations called defining
words. A defining word takes the next word in the input
stream (here ‘POLY’), and prepares an entry for it in the
dictionary of Forth definitions. As explained later, the
dictionary is the most central concept in Forth. In fact, in the
entire Forth system, including compiler, text editor, operating
system, etc. and also the user’s application software, less than
50 bytes of code are not part of the dictionary.
Besides opening a dictionary entry, the colon also places
the system into compile mode, so that operations which
follow are compiled into the definitions, instead of being
executed immediately. It is, however, possible to have special
immediate operations within definitions, when compile-time
execution is desired. The system stays in compile mode until
the definition is terminated by a semicolon. Notice that blanks
must be used as delimiters for colon, semicolon, and all other
operations.
‘DUP’ is an operation to duplicate the top of the stack,
i.e. to push a copy of the top item onto the stack. ‘SWAP’
reverses the top two items on the stack, **’ and ’ are
multiply and subtract.
For this illustration, assume that ‘POLY’ is executed with
the argument ‘6’ on the stack. First the ‘6’ is duplicated twice,
leaving three copies of ‘6’ on the stack. Then multiplication
is executed, leaving the stack as follows:
36
6
And ‘5*’ pushes ‘5’ and multiplies, leaving 5X 2 (180) on top
of the stack, with the copy of X beneath.
‘SWAP 7*-’ brings the copy of X to the top of the stack,
multiplies by 7, and subtracts. ‘10 -’ completes the poly¬
nomial.
To test the program, the user could type:
3 POLY.
where V is the command to print the value of top of the stack
(the V could have been included in the definition of ‘POLY’).
The system responds:
14 OK
where ‘OK’ is the prompt meaning that the system is finished
and waiting for the next input. (The underline means it was
typed by the system.)
The user may do some further testing:
75 POLY . 27590 OK
90 POLY . - 25676 OK
Notice the overflow on the last example; the width of the
stack is always 16 bits in standard Forth, although double
precision or floating point can be implemented, using more
than one stack entry to represent a number.
It is important to test that the routine doesn’t leave any¬
thing extra on the stack, because stack overflow is not checked
during execution and can be hard to diagnose. The instruction,
‘S, pushes the absolute machine address of the top of the stack
onto the stack. This address should be the same after a test of
an operation as before (provided that arguments are supplied
and results printed by the test). E.g. to test ‘POLY’:
‘S . 174 OK
8 POLY . 254 OK
‘S . 174 OK
Example: Number Bases
Any number base can be used: ‘DECIMAL’, ‘HEX’,
‘OCTAL’, ‘BINARY’, ‘5 BASE’, ‘17 BASE’, etc. For bases
above 16, letters after ‘F’ in the alphabet will be used as num¬
bers. The base can be changed at any time. Only the terminal
I/O is affected—all internal work is in binary, so there is little
cost for arbitrary number bases. E.g.
DECIMAL 666 23 BASE ! . DECIMAL 15M OK
This code means: make sure the system is in decimal; enter
decimal 666, then 23, onto the stack; enter the address of the
system’s variable ‘BASE’ onto the stack; store (the *!’ opera¬
tion) 23 into ‘BASE’, which sets the base to 23 and destroys
the address of ‘BASE’ and the number ‘23’ on the stack; print
666 in base 23 (15M); and restore the base to decimal, for the
sake of future definitions or data entry. By convention, the
standard base is decimal.
Example: Scaling
Software floating point has seldom been implemented in
microcomputer Forth until recently, and still is not available
on most systems (it is more common on larger Forth versions
for minicomputers). Instead, Forth has used some tricks for
getting around the need for floating point, such as a special
scaling operation ‘/*MOD’ (multiply and then divide, leaving
quotient and remainder), which keeps a 24-bit intermediate
result (instead of keeping only 16 bits as would happen if reg¬
ular multiply and divide operations were used). So powerful
are these special operations that Forth without floating point
has been used for such applications as non-linear least squares,
Fourier transforms, and numerical integration.
For this example, we want a program to multiply a number
by 3.14159. The challenge is that we are working in fixed
point, using 16-bit signed numbers with maximum value of
32,767. Also, the division operation in this version of Forth
only allows divisors up to 128.
Although it doesn’t make much difference in this short
example, the Forth programmer is strongly advised to start
with a top-down approach, taking the whole task and break¬
ing it into operations which could implement the entire job
in a couple lines of code, then breaking down these operations,
etc. The alternative is to start out defining operations which
seem to be relevant to the applications, but may not turn out
to be useful. Don’t be tempted down the wrong path by the
fact that the lower-level operations must be typed in first.
In this case we can break up the task of scaling by a six-digit
number (which would not even fit into a word) into three
scalings by two digits each. We notice that divisions are by
100, which is allowed, and that no intermediate results on the
stack will be any larger than the answer, avoiding overflow
problems. The final program becomes:
: FIRSTSCALE 31 10 */ ;
: NEXTSCALE 41 100 */ 10/;
: LASTSCALE 59 100 */ 100 / 10 / ;
: PI DUP FIRSTSCALE OVER NEXTSCALE +
SWAP LASTSCALE + ;
Now the user can type:
10000 PI . 31415 OK
or use PI in other definitions.
The ‘OVER’ operation copies the second element on the
stack without destroying it and pushes the copy onto the
stack. The scaling operation ‘*/’ is like ‘*/MOD’, except that
only the quotient, not the remainder, is returned.
Page 22
216
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
The reader can follow through this example. Typing, e.g.,
‘10000 PIfirst pushes 10000 onto the stack, then executes
‘PI’. ‘PI’ duplicats the stack, then executes ‘FIRSTSCALE’,
which pushes 31, then 10, then executes the scaling operation
which multiplies 10000 by 31 (keeping 24 bits for the result),
then divides by 10, returning a 16-bit result. Now the stack is:
31000
10000
and execution continues with ‘OVER’, ‘NEXTSCALE’, *+’, etc;
For efficiency, this example could be improved by first
translating 3.14159 to octal or hex, then using Forth’s assemb¬
ler to write a divide-by-shifting routine, as the standard divide
software is not smart enough to recognize that a divisor is a
power of two. However, run-time speed would not be much
improved by defining this program in one operation instead of
four, because linkage between routines is very fast. The over¬
head in number-crunching applications is due more to stack
manipulation than to linkage. And when time is critical, the
Forth assembler is convenient.
Example: Complete Session
The ‘PI’ example illustrated some practical advantages of
Forth for software development. It is no surprise that this pro¬
gram worked on the first try. Testing was immediate. The
operation is now available for any further use, simply by writ¬
ing its name. This routine takes about 75 bytes of object
code; the compactness would be more impressive it it were
part of an applications package in which references to ‘PI’,
which take two bytes, were used a few times.
The following listing shows the same example, but in a
complete terminal session including use of the editor. This ses¬
sion starts after the Forth system has been loaded. Loading the
system takes about 30 seconds on the 6502; this includes com¬
pilation of all but the first 2K bytes, which must be pre¬
compiled because it includes operations necessary for the sys¬
tem to perform compilation. The rest of the system code is
left in source form, to allow user modifications. Because com¬
pilation is fast, there is no need to store object code on disk,
hence no need for relocation. While overlays can be defined,
Forth is so compact that they are seldom needed.
42 LI SI
5LK *_ 42_
Q
jL
3-
3
.2
_a
_2
m
11
JiL
Ui
}JL
2-5-
OK
EDI lOh £&
0 P ( n UL 71 PLY BY : • 1 41 59 ) Q&
1 P : FI hSI SCALE 31 10 ; Q£L
2 P : NEXTSCALE 41 IOO */ 10/1 QH
3 P : LASTSCALE 59 1 00 */ 100 / 10 / I OK.
4 P s PI DUP FI kSl SCALE OVER NEXTSCALE ♦ SWAP LASTSCALE ♦ I OK
42 LOAD £&
10000 PI . 3141 5 _0K
•S'. 176 OK
A 5 PI . 1_4U OK
*S . 176 OjL
The user listed a disk screen (here number 42) to confirm
that it was empty. Then the word ‘EDITOR’ invoked the
editor vocabulary. This does not load the editor, which is com-
Number 25
pact enough to normally reside in RAM (though it can be
loaded when used, if memory is tight). Instead, ‘EDITOR’
caused the editor operations to be recognized.
The program is typed using the editor’s ‘P’ command,
which places the new line being typed into the line number
given, destroying whatever may have been in that line before.
There are several other editor commands not shown here. This
is a line editor, and cannot modify within a line. A more
sophisticated string editor has been developed.
‘42 LOAD’ causes the disk screen to be input just as if the
information had been typed; this causes the compilation to be
performed. Some tests of ‘PI’ are shown. The answer is correct
(though not rounded in the last place); and the operation does
not leave anything extra on the stack, or take anything away
except its argument.
Example: Using the Assembler
To invoke the assembler, begin a definition with ‘CODE’
instead of *:’. The manufacturer’s mnemonics are available,
plus ‘IF,’, ‘ELSE,’, and ‘THEN,’ for conditional branching,
and ‘BEGIN,’ ‘END,’ for conditional looping. These struc¬
tured primitives can be nested to at least 16 levels, because a
stack is used at assembly time. The assembly instructions
must be entered in postfix: operand, mode indicator if any,
then op code. Incidently this entire assembler as implemented
in Forth takes only a few hundred bytes, mostly for storing
the manufacturer’s mnemonics.
An example of a code definition (for the 6502) is:
CODE DIV256 0 ,X LDA, 1 ,X STA,
0<IF, FF # LDA, ELSE, 00 # LDA, THEN,
0 ,X STA, NEXT JMP,
The operation ‘DIV256’ is here defined as a fast divide by
256. It is used to same way as any other operation; it is trans¬
parent to the user whether a routine is implemented in Forth
or in code. For examples of use, see below.
Note that the op codes and some other names end in
commas. In this version of Forth, it is conventional that oper¬
ation names which actually place information into the code
stream end with commas; these operations serve as the end of
a phrase. The other names and numbers place values onto the
stack, which the comman operations will use. For example,
‘0<’ places a value (an op code) that sets up what ‘IF,’ will
test for.
Though not used in this example, the full power of Forth is
available at assembly time for computing address displace¬
ments. Use of the assembler does not enter into any special
assembly or compile mode (it does invoke the assembler
vocabulary so that assembly mnemonics are recognized).
Therefore, all Forth operations are available for execution as
normal.
The assembler’s conditionals (e.g. ‘IF,’) are simply Forth
operations which are executed when typed, like any others.
They are like macros, placing one or more machine-language
instructions into the dictionary where the definition is being
entered. Sometimes a forward branch is required (e.g. by
‘IF,’), and of course the address to branch to is unknown at
the time. The macro simply leaves an empty space for an
address or a byte count, and also puts the address of that
empty space onto the stack. Later, the operation which marks
the branch-to point simply takes that address off the stack,
and patches in the final offset or address required. Incidently,
the advanced programmer can deliberately produce non-
structured control, by manipulating the stack during assembly.
Though not shown here, the assembler also has a ‘BEGIN,’
... ‘END,’ looping structure, which repeats until the value on
top of the stack becomes non -zero (true).
The following session entered and tested the definition of
‘DIV256’.
Page 23
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
217
EDI 1 OH
0 P t ASSEMBLER EXAMPLE ) 2K
1 P HEX
2 P CODE DIV2S6 0 .X LDA. I .X S1A. OK
3 P 0< 1 F» FF * LDA. ELSE. 00 # LDA. 1HEN. OK
4 P 0 .X STA NEXT Ji-iP. U!S.
FLUSH QjS
43 LOAD Sl£ 1
EDI TOR OJl
SCR 7 42 2K.
4 P 0 .X STA, NEXT JMP. OX
FLUSH Q£
43 LOAD 01
77 DI V2S6 • Si 2B
300 D1V2 56 • j).OK
DECIMAL OK
77 Dl V 256 . Dl V T_
77 Dl V256 . 0. .OK
400 DI V2 56 . J_OIS
10000 DIV2 56 T 22 Oa
- 300 DI V2 56 . -2 OK
- 3 Dl V2S6 • ij. 0£
-2 56 Dl V2S6 . - I OK
-257 DI V/f? 56 . ^2 pi
This session has some errors; e.g. in the sixth line, ‘STA’ has
the comma omitted. The error message ‘STA ?’ was printed in
the eighth line. In the seventeenth line, mistyping the opera¬
tion name caused ‘DIV’ to be unrecognized. Notice that ‘HEX’
stayed in effect after the code entry, until the ‘DECIMAL’
operation in line 16. Also, all quotients are truncated down¬
ward, even negative quotients, e.g. ‘-3 DIV256 . -1 OK ’
‘FLUSH’ writes the updated buffers to disk, making sure tKat
the copy of the program is actually saved. ‘SCR .’ places the
address of the system’s variable ‘SCR’, which holds the
number of the disk screen being worked on, onto the stack,
then *?’ takes the address off the top of the stack, and prints
the quantity at that address.
Example, LIFE
The following Life program was contributed by Dave
Boulton, of Quesnoy Corp. Object code is 475 bytes; Forth
works better for larger programs where application-oriented
libraries can be developed. This program took an hour and a
half to write and five minutes to debug. It runs slowly, and
could be speeded up by re-coding the two levels of inner loop
in assembly.
100
0
1
2
4
5
6
7
8
9
10
11
12
13
14
15
LIST 101 LIST
( TEL GAME OF LIFE ) FORTE DEFINITIONS FORGET TASK : TASK
81 CONSTANT XLEN 25 CONSTANT YLEN
XLEN 1 - YLEN 1 - ARRAY UNIVERSE
: CEECK DU? 3 = IF DROP 2+
ELSE 2 = NOT
IF 4 + THEN THFN J
: CLEAR YLEN 0 DO XLEN 0 DO 0 I J UNIVERSE Cl LOOP LOOP
: SET SWAP UNIVERSE 1 SWAP C! J
: RESET SWAP UNIVERSE 0 SWAP Cl ]
: DISPLAY HOMEUP XLEN 0 DO [ _] LOOP CR
YLEN 0 DO XLEN 0 DO
I J UNIVERSE CO IF [ *] ELSE SPACE THEN
LOOP CR LOOP ;
101 LOAD
9
I
0 ( LIFE CONTINUED )
1
: GENERATE
YLEN 0
DO XLEN 0
DO
0
2
J 2
+ YLEN MIN
J 1
- 0 MAX DO
3
J 2
+ XLEN MIN
J 1
- 0 MAX DO
4
I
J UNIVERSE
CO
1 AND
+
5
LOOP
LOOP
6
I J UNIVERSE CO 1
AND
SWAP
OVER -
7
8
o
CHECK I
J UNIVERSE
Cl
LOOP
LOOP
•
9
: NORMALIZE
YLEN 0
DO XLEN 0
DO
10
I J
UNIVERSE DUP CO
DUP
3 >
11
IF
DROP 0 ELSE DUP 1 >
12
IF
DROP 1
THEN
THEN
13
LOOP LOOP ;
14
: SIZE 1+
81 MIN
['] XLEN 1
1+
25 MI
N [']
YLEN
15 : GENERATIONS 0 DO DISPLAY GENERATE NORMALIZE LOOP
SWAP C!
DISPLAY
»
24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
.
Instead of giving a total explanation of this program, which
would expand this article into a language manual, we will
sketch how it works and browse some of the mysteries.
The program is on two screens, numbers 100 and 101. The
first line lists them both. Each screen has line numbers 0
through 15. By convention, line 0 contains a comment describ¬
ing the screen.
Forth comments are enclosed in parentheses. The left
parenthesis must be surrounded by blanks. The right paren¬
thesis need not be preceded by a blank, though by convention
it usually is. The reason for this asymmetry is that the left
parenthesis is a Forth operation which causes an arbitrary
character string to be skipped until a right parenthesis, which
is a delimiter, if found.
The ‘GENERATIONS’ definition, screen 101 line 15, is the
main loop of the program. It contains a ‘DO’.. . ‘LOOP’. ‘DO’
takes two arguments from the stack, the initial value from the
top, and a termination value below it. Looping stops one short
of the termination value; e.g. ‘15 0 DO ... LOOP’ loops 15
times, with the index going from 0 through 14. Arbitrary com¬
putation of looping parameters is of course allowed, since ‘DO’
doesn’t care how its arguments got on the stack.
It may seem strange to have the loop termination value
before the initialization, the reverse order from BASIC and
others. But this way you can say, e.g., ‘15 GENERATIONS’,
which puts 15 on the stack and executes ‘GENERATIONS’,
which puts 0 on the stack and executes ‘DO’. We more often
want to pass a termination value than an initialization value to
a routine.
The Forth operation ‘I’ places onto the stack the current
value of the index of the innermost ‘DO’ loop. This leads to a
very strange fact in lines 2 and 3 of screen 101: ‘J’ refers to
different ‘DO’ loops in the two lines, because the ‘DO’ at the
end of line 2 has changed the level of nesting.
‘XLEN 1-YLEN 1-ARRAY UNIVERSE’ creates an array
named ‘UNIVERSE’, or dimensions 80 by 24 because XLEN
and YLEN were created with values 81 and 25 in the preced¬
ing line. Notice that these statements are outside of any colon
definition; they are executed immediately when typed, at
“compile time” (although it is “run time” for the ‘CONSTANT’
and ‘ARRAY’ defining words). In Forth, compile time and run
time are definitely separated yet very much interspersed).
‘I J UNIVERSE C@’ places the values of ‘I’ and ‘J’ on the
stack, then executes ‘UNIVERSE’, which is an 80 by 24 byte
array, but is also an operation. ‘UNIVERSE’ takes two index
values from the stack, and returns the address of the selected
byte. Then ‘C@’ takes whatever address is on top of the stack,
and replaces it by the value of the byte at that address (in the
low-order eight bits of the 16-bit top of the stack). Hence
constructions like:
I J UNIVERSE C@ 1 AND +
which takes the I, J byte, logically ANDs it’s value with 1, and
adds the result to the top of the stack. That is, it increments a
counter (on the stack) if the addressed byte has a ‘1’ in its low-
order bit. This statement is counting how many are alive in the
three by three square surrounding the character in question.
The character itself is counted, though it should not be, so it
is subtracted out by line six of screen 101.
Line 14, screen 101, is an optional operation to allow the
size of the array to be changed—but never to go over 80 by
24. The operation ‘ [’] ’ gets the address of whatever follows it
(in this case the constant ‘XLEN’ or ‘YLEN’). Later, *!’ stores
the second item on the stack into the address on top of the
stack. In other words, this line changes the values of
“constants” ‘XLEN’ and ‘YLEN’. Operations like *[’]’ are
mainly intended for use in implementing the Forth system,
but they are available to the applications programmer.
Incidently, the ‘ARRAY 1 operation (which created
‘UNIVERSE’) was itself defined by the programmer in two
lines of code not shown here. ‘ARRAY’ is an example of a
user-defined variabletype. The full power of Forth is
available to specify what happens at compile time (e.g. allo¬
cate space for the variable, if a static variable is wanted), and
at run time (e.g. compute an address in the array, given sub¬
scripts).
One more operation which should be explained is
‘IF’... ‘ELSE’... ‘THEN’, e.g. in line 13 of screen 100,
I J UNIVERSE C@ IF [ *] ELSE SPACE THEN
The ‘IF’ operation takes one argument off the stack. If it is
non-zero (true), the phrase after the ‘IF’ is executed; it it is
zero (false), the phrase after the ‘ELSE’ is executed, if there is
an ‘ELSE’ phrase. In either case, control resumes after the
‘THEN’. This line takes a character from the array, and if it
is non-zero prints an asterisk (left bracket introduces a literal
string to be printed, and seeks a right bracket as delimiter), or
if the character is zero prints a space.
Forth isn’t difficult—as this condensed description may
make it seem. Just unusual.
How it Works—Internals
We don’t know of any implementation documents. This
section is a sketch in that direction.
The basic structure of Forth is simple. The difficult part of
the language design is the selection of operations such that the
language is able to implement itself gracefully. And the coding
of the Forth system operations can be very dense. At this
point we are concerned with the structure of the system, not
the semantics of the particular operations. For a fuller descrip¬
tion of the language itself, see the Decus manual (reference
in bibliography), which to our knowledge is the most complete
documentation readily available today. For a fuller description
of the internals and implementation, check future publications
of the Forth Interest Group, 787 Old County Rd., San Carlos,
CA 94070.
The central structure of Forth is the dictionary. Every oper¬
ation, primitive or defined, has an entry in the dictionary. All
applications software, and virtually all of the Forth system,
consist of dictionary entries. Of the 5K to 6K bytes of a
typical microcomputer Forth system, only about 50 bytes are
not part of a dictionary entry.
All dictionary entries have the same format. In most Forth
systems, the first four bytes identify the word; the total length
of the word, and the first three characrers, are saved. Opera¬
tion names may have any length; but if they have the first
three characters and length the same, they will not be distin¬
guished. This system works quite well, and confusion is rare.
Besides the length, the first byte also has a precedence bit ,
which tells whether the operation is immediate or not. Immed¬
iate operations are executed even when the system is in com¬
pile mode, and usually act as compiler directives or macros.
Compile mode is set by the colon, and cleared by the semicolon.
The next two bytes have the link address. This is simply a
pointer to the previous dictionary entry. Its purpose is to
allow the dictionary to be searched, at compile time.
The next two bytes are the code address. This address is
fundamental. It always points to machine code. In a code
operation (either a primitive, or a user-defined assembler
routine) it points to the code which implements the operation;
this code begins immediately after the code pointer. In a colon
definition (i.e. a standard Forth statement), it points to code
which controls nesting at run time, described below. In a
variable, the situation is more complicated. In this case, the
code address points to code in the dictionary entry of a
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 25
219
defining word—a kind of operation which (a) when used at
compile time makes a new entry in the dictionary, and
(b) contains code which is unique to that particular class or
type of variable, and which is executed at run time.
The eight bytes described above form the header of the
dictionary entry which defines any Forth operation—code
routine, colon definition, or variable. The body of the diction¬
ary entry consists either of machine language, a list of
addresses of previously-defined operations (which may have
literals interspersed, each preceded by the address of a literal¬
handling routine), or the value or address of the variable,
array, etc., respectively.
Now we know what the dictionary looks like, for it is
nothing more than a string of these dictionary entries. And
the dictionary makes up virtually all of Forth —the compiler,
assembler, operating system, and all application software
written by the user. Only about 50 bytes of code are outside
of the dictionary. This little bit of code, known as the inner
interpreter, is the heart of the system.
At run time, all operation names have been replaced by the
addresses of their dictionary entries, so the inner interpreter
works with addresses only, and never has to search the
dictionary. The inner interpreter uses a pointer, ‘F, to the next
address in a definition to be executed. If possible, T will be
kept in a register, because the inner interpreter must be ultra
fast.
Consider a particular dictionary entry for a Forth defini¬
tion, and assume that one of the operation addresses in its
body is just finished being executed. T now points to that
address in the dictionary entry.
If the routine which is finishing is a code routine (primitive
or user-defined), it will end with a machine-language branch
to the location ‘NEXT’ in the inner interpreter. There, code
will increment the ‘I’ pointer by two, leaving it pointing to the
dictionary entry of the next operation to be executed. By an
indirect fetch from T, the code address of this new entry is
moved into another pointer called ‘W\ Then the inner inter¬
preter branches indirectly to *W’; i.e., it branches to the code
address of the next routine to be executed; the code address
always points to machine code. This linkage process takes as
little as two instructions on minis and eight or so instructions
on eight-bit micros.
This is the linkage from one code routine to another. If
the new routine is not code but is a Forth definition instead,
then the code address in its dictionary header points to code
which handles the nesting by pushing ‘I’ onto the return stack,
then setting T from ‘W’ to point to the address just before the
body of the Forth definition, then branching to ‘NEXT’.
Similarly, when the Forth definition ends, the semicolon
operation points to code which pops the return stack into T
(removing the last level of nesting), then branches to ‘NEXT’.
There is also some auxiliary code for performing stack opera¬
tions and then falling directly through into ‘NEXT’, for
efficiency.
This completes the description of the inner interpreter and
of the nested execution of Forth operations. This linkage
happens at all times—compilation, assembly, editing, or
execution of applications software. In fact there is no funda¬
mental distinction between these times, as the whole Forth
system, including the user’s application software, is one unit.
Miscellaneous Features
Multitasking
Forth is well suited to multitasking, which has been imple¬
mented on minis (though not as of now on micros). E.g. a
Nova 2 (35K words) has handled up to 32 terminal users
simultaneously. To switch users, only four pointers have to be
changed. Each user has a private vocabulary, in addition to the
common vocabulary. Communication between users is accom¬
plished by simply leaving messages in agreed-upon places.
Also on minis, a data base management system has been
implemented as a Forth superset.
Disk Managem en t
Virtual-memory software is standard for both micros and
minis. Data is read and written in 128-byte blocks. The editor
addresses 8-block (IK) units, which are called screens because
they fill 16 lines of 64 characters each on a CRT. (A CRT used
on a Forth system should be able to display 16 lines of 64
characters.)
The system should have memory room for at least 8 block
buffers, so that a whole screen can be displayed; the same buf¬
fers are also used for applications and disk I/O. Programs
request blocks by number, without regard to whether they are
in memory or must be brought in from disk; the system checks
whether the block is in a buffer already, reads it from the disk
if not, and returns the memory address of the block on the
stack. Programs can use the ‘UPDATE’ command to mark a
block as changed; it will be written to disk before that buffer
is re-used. ‘FLUSH’ will write all updated buffers which are
currently in memory.
The system treats input identically, whether it comes from
the disk or is typed in. This allows use of ‘load screens’, which
contain commands to load other screens, so that the system
and/or applications programs can be loaded automatically.
Dictionary Management
Forth is hard to categorize as interpreter, assembler or
compiler, and some have even questioned whether it is a lan¬
guage. Whenever a character string is typed into Forth, it is
first looked up in the dictionary. Only the first three charac¬
ters (five in some Forth versions) and total name length are
used for the match. If the name is not in the dictionary, the
system tries to make a number out of it, using the number
base which is currently in effect; if that cannot be done, an
error message is issued. Forth operations must be defined
before they are used.
It is OK to re-define a name which is already in the diction¬
ary. Later uses of the name refer to the new definition, but
earlier uses continue to refer to the old one (these earlier
references have already been compiled). This means that there
is no worry about accidently re-using a name, unless the old
meaning must be used again the same program. Therefore the
programmer can freely make use of temporary names in build¬
ing up the definitions of new operations, without worrying
about later conflicts.
For convenience, it is possible to ‘JOIN’ non-adjacent
definitions, taking all intermediate definitions out of the
dictionary search path.
There is also a ‘FORGET’ command, to wipe out the most
recent dictionary entries. It is used to clear away recent
scratch work. Care is advised. Forth allows you to ‘FORGET’
the entire system.
But the most powerful form of dictionary management is
the use of vocabularies. Each vocabulary is a separate linked
list of dictionary entries. Vocabularies are used to control the
order of dictionary search. There is an ‘ASSEMBLER’ vocab¬
ulary which contains the op codes, etc; and ‘EDITOR’
vocabulary contains text editor commands. Also, users may
define their own application vocabularies. All vocabularies
link into the ‘FORTH’ vocabulary, which is the root of the
vocabulary tree. In other words, if an operation name is
not found in whichever special vocabulary is in effect, the
‘FORTH’ vocabulary will be searched. Users can define
sub-vocabularies which similarly link into each other.
Vocabularies are implemented by the link pointers in the
dictionary entries. In addition, each vocabulary has a diction-
Page 26
220
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
ary entry in its root vocabulary; this entry associates the
vocabulary’s names with a pointer to its last dictionary
entry.
At any time, two vocabularies are in effect: ‘CONTEXT’
and ‘CURRENT’. ‘CONTEXT’ works as described above,
determining the path of dictionary search. ‘CURRENT’ tells
which vocabulary new definitions will be linked into. If
all this gets confusing, keep in mind that in any Forth system
there is only one dictionary, but there may be many vocab¬
ularies. Further discussion of vocabularies is beyond the scope
of this article.
Microcode
There is much interest in microcode implementation of
Forth. One approach is to microcode only the inner inter¬
preter. At most this could double the speed on micros and less
on minis, so it would probably be more practical to use a
faster chip instead.
The other approach is to microcode all 40 or so of the
primitives, plus a few other operations for completeness (as
there would be no “machine language” to drop out of “Forth”
into). Such a machine would be many times faster. While work
is proceeding, we don’t know of anyone who has done it yet.
Transportability
Forth is easy to move to new machines, because only IK
bytes must be re-written. An experienced implementer can do
it in a few weeks. Some care must be used when transporting
higher-level definitions to machines of a different architecture
—e.g. when going between high-order vs. low-order byte first,
character arrays may need attention.
Cross-compilation is possible, but complicated because
Forth operations need two definitions, a separate one for the
target machine.
Complex vocabulary manipulations are used to keep the
two sets of definitions separate. Cross-compilation is common¬
ly used when the target machine is the same chip, but to run
without a terminal and perhaps from ROM, e.g. for control
applications. In this case the purpose is to compress the pro¬
gram by eliminating those primitives and definitions which are
only used by the compiler, and to shorten the remaining
definitions by removing the name characters and the link
pointer (which are only needed during compilation).
History and Availability
Forth was developed by Charles H. Moore around 1970, at
the National Radio Astronomy Observatory, and to our know¬
ledge was first described in publication in 1973 1 . Later Mr.
Moore left the NRAO and is now marketing the language
through Forth, Inc., 815 Manhattan Ave., Manhattan Beach,
CA 90266. The price is $10,000 for the larger, minicomputer
timesharing version, including on-site training. The micro¬
computer version is $2,500, sent by mail and including tele¬
phone consulting. A “primer” is available separately at
nominal cost. As of May 1977, Forth Inc. offered implementa¬
tions on the COSMAC, 8080, 6800, Z-80, and LSI-11.
A version of Forth for the PDP-11 is available through DEC
Users’ Society, 126 Parker St., Maynard, MA 01754. Distribu¬
tion charge is $60 for tape, or $23 for floppy. It runs under
RT-11 or stand-along, and needs 8K. PDP-11 Forth is DECUS
No.11-232.
The DECUS manual is sold separately, for $2. This is the
only manual we know which is readily available to the public
at this time.
Also on the 11, Doug Faunt, PO 60116, Sunnyvale, CA
94088, or phone (415) 494-7030, will soon be publishing
the LSI-11 Newsletter, can supply a DECUS floppy version in
exchange for a floppy and return envelope.
For CP/M, a Forth version called STOIC is available from
the CP/M Users Group, 164 W. 83rd St., New York, NY
10024. STOIC is Vol. #23, and the distribution charge is $8.
Documentation is on the floppy.
The STOIC system takes about 13K for its basic definition
and assembler; why is it so much larger than other systems?
Several K are used for buffers to interface CP/M; and the first
five characters of each name, instead of three, are saved in
each dictionary definition. Also there are many more opera¬
tions than in the smaller system, such as a more complete
signed and unsigned arithmetic. STOIC also has additional
packages for vector and matrix operations, double precision,
and floating point.
Forth versions are running at various universities and
research institutions; Rather and Moore 7 list three where it is
available. Also, University of Rochester and University of
Arizona have implementations on Varian 620-1, CDC 6600,
PDP-11, and IBM370. We don’t know about distribution
arrangements.
For the Z-80, the Digital Group, PO 6528, Denver, CO
80206, has announced CONVERS, its version of Forth, to sell
for $26, with the manual selling separately for $10, creditable
toward purchase. However, the product is not yet out.
For the Alpha Micro, a version is being developed by Alpha
Micro Systems, 17875 N. Sky Park, Suite N, Irvine, CA 92714.
Programma Consultants, 3400 Wilshire Blvd., Los Angeles,
CA 90010, is developing Forth versions for the 6800, 6502
machines (Apple, PET, OSI), and other micros. These are
intended to run without floppies.
A newly formed Forth Interest Group, 787 Old County
Rd., San Carlos, CA 94070, is an information clearinghouse on
the language; it does not have a version for distribution at this
time.
Summary
Only recently have sophisticated programming languages
become available for home computers and small development
systems. There are others besides Forth, such as Pascal, or C.
Probably each has certain applications which it can do best.
Forth is very different from anything else. It is remarkable
that so rich a language, which is also a stand-alone operating
system, can be implemented with 6K bytes.
Software development times can be greatly reduced, espec¬
ially for large projects. Rather and Moore 7 give as example a
radiotelescope control and data analysis system, including
on-line interactive graphics, which they claim would typically
be estimated at six man years and with 64K of memory
required. It was implemented in Forth in 24 man weeks and
16K.
1. Moore, C.H., and E.D. Rather, "The FORTH program for spectral
line observing," Proc. IEEE, vol. 61, September, 1973, pp. 1346-
1349.
2. —, "FORTH: A new way to program a minicomputer," Astron.
Astrophys. Suppl. 15 1974, pp. 497-511.
3. DECUS, Forth Programming System for the PDP-11 , DECUS No.
11-232, September 1975. (Note also manual for the PDP-10.)
4. Stein, P., "The FORTH dimension: Mini language has many faces,"
Computer Decisions, November, 1975, pp. 10.
5. Rather, E.D., and C.H. Moore, "FORTH high-level programming
technique on microprocessors." Presented at Electro/76 Professional
Program (paper 23/4), Boston, MA, 11-14 May 1976.
6. Sinclair, W.S., "Forth: A Stack Oriented Language," Interface Age,
September 1976.
7. —, "The FORTH approach to operating systems," A CM '76 Proc.,
pp. 233-240, October 1976.
8. Forth, Inc., Microforth Primer, December 1976.
9. —, "The use of 'FORTH' in process control." Presented at Inter¬
national '77 Mini-Micro Computer Conference, Geneva, 26 May
1977.
Number 25
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Page 27
221
RESIDENT MEMORY TEST
With An Example For The 6800
BY TERRY RITTER
Motorola, Inc.
3501 Ed Bluestein Blvd.
Austin, TX 78721
© 1978, Motorola, Inc.
Reprinted with permission
A memory test package can be a very useful utility for a
microcomputer system. Not only can it provide periodic
checks of memory functionality, but it can also give day-to-
day checks of the system after re-configuration. Getting a
moderately-complex program to actually execute says a great
deal about the correctness of the entire computer. Testing the
area which is supposedly RAM isolates address-decode and
board-contact problems which could otherwise inhibit opera¬
tions. A small and fast memory test package can confirm the
correctness of a dynamically-changing system to a high degree
of probability.
A resident memory test system must usually assume some
degree of RAM correctness in order to execute the program
(even if executed from ROM, the program will probably need
temporary storage, and will inevitably use subroutines).
Further, since RAM is being tested under the control of an
instruction sequence also derived from memory, the test pro¬
gram cannot check access times. Dynamic RAM refresh prob¬
lems are especially difficult to check, since all memory acces¬
ses should be halted while stored charge is given the oppor¬
tunity to leak from inside dynamic nodes. At room tempera¬
ture, this may need to be a minute or so, making the resulting
test very long. Nor do most systems even consider temperature
or operating voltages which will define the limits of valid mem¬
ory operation. A resident memory test is functional only, and
valid only at one point in time.
Nevertheless, it is possible to make a reasonably fast and
effective memory test system. At the very least, each memory
bit must be written to a ‘1’ and recovered as a ‘1’, and written
to a ‘0’ then recovered as a ‘O’. This is possible using a simple
“write $FF, check, write $00, check” sequence, but this
sequence will not detect changes in other address locations
which are caused by these operations. A better method is to
store a pattern over the entire test area then recheck every
location after each write to a particular cell, but this is clearly
an N 2 algorithm, in terms of time.
Another test method is to place a known sequence of bytes
in the test area, then recover this data and compare it to the
internally-generated sequence. Two passes of a known pattern
can check each bit in memory. But if the pattern has a length
divisible by 2—and is shorter than the tested area—the same
byte values could appear in similar areas within, say, two dif¬
ferent pages. Now, if an address-decoding fault causes a single
memory block to be enabled for multiple address blocks, and
similar data is stored in each address block, the error will not
be apparent (since the second write pass in the enabled block
writes the same data as the first pass, it may be considered not
to have occurred). A testing improvement results by
generating a sequence whose length is relatively-prime to the
minimum enable-block size (say, IK). Now, the same byte
value cannot appear at a similar location on different multiply-
decoded pages, and the error of multiple address decoding will
be detected.
Once an acceptable test algorithm has been found it is
necessary to consider the operator interface. It is clearly neces¬
sary to be able to define the test area, and any error displays
should include both the error address and indicate the bit-in-
error. The program must be operator interruptable, both to
halt a long error listing, and to re-specify the test area. The
operator should be able to command a return to the overall
calling system. The program could be made to verify its
integrity before beginning. And, if the package is position-
independent, the program could be made to move to a new
location to test the area where it was originally located.
Most of these principles are included in the program
MTEST9. Written as an example of a standard-product ROM,
it can be used with different hardware designs having ROM,
RAM, and I/O at arbitrary locations. The sample output
shows execution of various options, as well as the ramifica¬
tions of some different types of inappropriate commands.
Page 28 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 25
222
— 3 3 r< 3 3 3 3
b- o C» C* O O O O o
— LJ LJ UJ LJ LJ LJ LJ LJ
3 x z
Cl - Ll
<_> in
I K
- Z -
: oo o ©
•1 Oj >—■ j •
* — X l- Ul
O Ct LI Z 111
I X X 3 i
•3 CL Ui
u) * in uj
o a it ^
- \ X Cl
O !2 Z I Cl
II — OX
O n
n Uj
O _l
© I d *- i—
ii I I u hi
X c> Cl o
I I I u u
X U O — -I o
<_> z z z z iu
C> — — — — Oj
•a -a i a i <i x x
u a ii a- a. n n n
fljiiiajixi&jiiiiiiaj
_i_J_
a ia. ioiii
— x u z - a i3
©ZljZZZZLJ
e — o —-co
>>>>>>>>
ii-i-i-i-j-i-i-i-
lii CD (it ID CO ( .0 ID <X>
Ul UJ
uj r
e —
x in -
»- _j u-
• 3 c
• 3 CO
x u. a >. ■
•— -i <-> a
aituL
a u <i in
o uj
z i
ui
a o o _i
u x »- OJ
oli ai
4 it Z >
in z - • i
E Z E X X h-
O LI l- — x
it x <r x w ^ q
L I u i?
U — X X *
li It 1 U. UJ 111 L
x <r :c x _i
x x k i- d
U U ll iL (L 9 u
lu Ul
Cl Q > > Cl Ci O
Z Z 7. Z Z Z L.
ul lit O O LlI LJ LJ
i/' in o o in ui in
- i- ui
iJiiiiit'iL.'io
U .< •< N 9 I- h J Ul •!
J-J-UUIJ-l-XXddd
3 3 i t 3 3 a cj o uj v>
c o u o o o a. u. u n &
•I T X 'I X X X 1 XXX
ll i ll: L ui L Hit ii it 0.
ill iXJ Oj i»j 01 lU 01 Oj ill 01 01
U JlZN’t'l* r- J
I- J- :< X I- F- X X d 0. d
j j uj m j I i u ii m i/i
c» o x i :• o cl a o. d d
>,->>>>>>:>>>
»— i— t->—i— »—»— i— i— t—
•10 CC> CO <0 10 CO 'O 10 lO 'O (O
Cl X
X 13
z o
- X
z a
- z
d X
U Cl
X X
ct ct
Oj OLI
Z Cl
- z
d X
Cl d
> >
- cn e
_J UJ o
x in d
- in Cl
h- UJ
- d _l
z a _i
-ox
X E
* X
o z
X d
E O
UJ X o
»- I- E
in in >
d O 3
UJ X X
tt * * «
O CO Cl
XX —J
J— Cl o
cn o
X CL
z a_ -
o uj
uj * *-
in oi o
Ul oc ct
J- CL *- O
3 d m u
_J 3
O <L X <c
cn i ci u
m j x d
X X ^ X
L- X X Q X (5
in — — — - oi
uiinuoci-Ljii -
F- I X X E * X ‘ ff>
Xd3>-XXZClX
LlJQClCliri-li ui
JO J J J(L l-_J
* e 0i e
co oo co g cn © co ui
E C»
O Cl
Cl UJ
Z I—
X Z Ul
0 : - z
i d -
O Cl J
d cl ci m cn d .
I <_! Cl
L Cl Cl
UJ c
o uj < ft a
Z T OX
-- u. a
i- Cl O X Z
ii O —
X Cl • Cl 'J
I- u. O Z LJ
01 UJ Z UJ Oj
d Ci
X X
X X
U O
u> g g eg oj ©
t* n n in f- o ji
u o :
c> x v
ci - ;
l O J "J O lO O I
> o a © o © o o ■:
j iu UJ U UJ Ul UJ LJ l
00 J-
3 ZOO
I 01 Cl 'J 3 X X
[ I- — LJ X O Cl <5
■ 3 X UJ J O Z UJ
I O E 01 L.' LJ (Cl
I I
o o
3 3
Z ©
L L L li '• 0j O 111
N 0j O UJ U li li U.
© fit © © © © © ©
S il C> £' i Cl O Ci
Q li h C> NCl I- Li
•fftADOUfOa
© 0J 0J ll 0J 01 0J —
CiC’ OCiCiCiCiCi
— 01 X ill U1
g «j cn m x
oj oj oj oj eg
O Ci Ci C) &
■Si U UJ OO 01
X X X 00 u
0J 0J 0J 0J 0J
© © © © ©
o
0J
&
in cxi
0J —
01
oj g- ui ui
till —
U W U U T- C 01 N
00UIU.U.U.N
co *t *t oj eg o u
O Ci C Si S Ci L
Cl Cl c> c- c> c- u.
Ci Ci C> Ci Ci Ci !L
UJ3QjO>ajl'-
II L. Ii li It U.
u u. u. u. u u
ui co xi cn Ui <ji uj ui
UJ Ul CH UJ f Si CO Ui CD CO cn cn
UJ
C0
N li UJ O UJ 9 U. 0J
01 U) O — CO 01 »-01
•s> c>
o «•
c. Ci
01 ‘A CD <_i H 0J in aj
Cl Ci Ci Ci Ci — — —
99999999
•SCiCiCiCiCiCiCi
oi uj t- •» r-
— ^ oj eg oj
■t g- -t g *t
C> Si Ci c* c>
x a c- oi uj cn
eg oj oi cn oi oi
g g g -t g^
Cl Ci ® Cl Ci Cl
U lL
01 01
eg ui x
g g g g
g g g- g
Ci Cl C- Ci
O’! Ul
ui in
g g
Ci Ci
0 - o m g> — eg oi g in
NNScOKiftiCJaiai
C- C* C> C’ C> C» C? C* Ci
o Cl c« & c* c- c* o c»
5i£>C05i®&S®
■o a»
<r.< oo
c. c>
— eg oi g ui u>
cn cn u> O' IT> Jr
Ci Ci C> O Ci c>
® O O ® £' ®
Ci Ci Ci O Ci c>
r-~ jo ui Ci —
u> cn j) c> ci
©ClClT--
Cl C> Ci C* Ci
Cl Ci Cl C> Cl
Ul Ui
O Ci
oomes — ojoiguiUin-oCiiTiCi—g ui
— oj oj eg oj eg eg oj eg oj eg ci oi oi oi
N oo lii ci — (g oi 9 uj ui 0 -
Oj C* - ! i t i g g g g g g g g
oo J: c> — OJ oi
g g Ui Ui Ui ui
®®®S®G®SOC‘®®
Ci Ci s>
O Cl Cl
Ci
Cl
G> C> Ci C> C* C« © C> Ci
©©©©Ci©©©©
Ci © © © © © Ci ©
©©©©©©©©
© :
a eg c
«j +
r> — Cl Cl
G HI u. IL
— UJ — H-
Ci \ \
-■ «> «1
L> U l 0- N
U Ul E
J- O X
in u. cl
cn i- 3
uj uj o •
i—jinr
LliO
> - <t Cl
d a
o -3 c> u.
E Z O
uj in
e — in it
UJ —
l- ‘ Ui
in o 3 d
x N UJ
li-QCi
X 3 X 3
UJ
in z ■ z
Ui ►
i- »- v l/i n x
x uj uj o i
O £1 Ll 1 h O l
O O C*. ll ~ 3 1
3 U. O UJ LJ C
u in x t
h U l UJ Ll 111 Ll I
in u ai cl — z -
d Ui CL
— Ui (ll * X ^
U Ul ll 1- E C
X 3 Z 3 — .
uj cn
Ul u.
- o
, i r
3. • i- .
O X Ul - <
U UJ
•- cn i
I- Cl U'l L .
U- 13 UJ O J
X I- ll o
3 ©
Ul Z iu
l/i — Oi
• *3 z oi :
: • x — h- :
b- o in *
i in ui — L.' •
: uj ci a. i- t
: x o e I
•ujou-xd — du.
d i o o i- ©
ia> •- ct — u. x
IQ_I V d ct >
j — a ui
i X 3 C
> Z 0 (
d cn i
: cn
J— Ul <3
in ►- z
ci l- e -
UJ Ul 3
I- UJ Ui 3
U I- J- X
X E Ct o
X
J- Z K- III
zuini
- I UJ J- •
Cl i- Ci i
cn ui i z i
UJ Ui
it ui
Ll a.
exx-
J J- u t
ioicn
ujucicidt o a
j — o d i
z - Ui
c O oj ui ui i
i- j- > uj d
E 0 3 0 1
l- O O C
3 UJ UJ C
O Ci Ul i
j a E
£ Cl UJ
-iini
: x — o
- o 3
- d o
j Ci UJ Cl
C 2 J< I
i :• uj j—
3 o z i ■
3 X 3
x uj x
Cl UJ Cl ^ X
Z 3 UJ
x o :> 3
UJ o o
pi a X LL >
I X UJ 3 I- O :
J UJ —
I Cl o
• Uj Cl X
Z E J
3 o d i- ac i
U Ll X Ll E I »
in z it rg u. > z
c uj in
Z Z X 3
X O 3
Cl I —
* J- 0 3
: 3 UJ d Z
l CL OJ UJ - I
3 3
3 O
— o
3 UJ
J 15 X
— in .
JLIU.
: z in in • _ _ _
-03inoi5U)33 — X 3
o a. i _
: o o ci i- *
n x z ©
c ui — a. uj <
cn cn i
C 3 UJ X Ui o
3 — Ul 3 Z d
• Z Ul 3 Cl O
J X X 3 X‘
— d X — l
I O O UJ 3 3
Cl 3 UJ X O
a o a. o x ii
X 3 U« O l
3 X ll '
UJ X Ui O
I- X ••
3 3 J- I N
O 01 Cl
E d U 3
- O it 3
Z Hi X 01 3 O — li :
ui cl x x z m — u. i
it 3 I- Cl X Ul J- II —
UJ UJ X UJ UJ o o
UL-3QKOZZ l
uujj- 3 z — in •;
— Uj Ci-IX*- l-d
© X Z 3 >■ Z UJ I
> in x uj o 3 hi i—
3 3 • J- it 3 E Ul
•ZCi_I01>- X UJ E
EO O+ilil-ZdX
UJ ' d I- 3d — d
©Quji-uiuja.uj3X
I/IUJI-ZUOI-I-OIL
>Ui-0l-03XU
enZOQOEEOUJdX
***♦.<
d X
o x :
u. o *
3 UJ _
i Ll CL UJ
i U. O X O X
3 Z <3 X UJ
d d X Ul IL d
■ O O O UJ Ul X
z-- - o
UJ O O O O O 2
UJ Ui Ui Ul Cl Ui I-
d x x x j a ui
3 3 3 3 3 3 2*
o o o o o o o
Ul UJ UJ ill LJ UJ UJ
id© u- x o a
— 3 3 O X X
iddi-uidi-
« e o o o uj in ui
g ui
Ll. U
o o
>©©©9Cigoj —
I g (J - © © © ©
, Ii Ii III Vi U Hi K
>3 333333
> o o o o o © o
J UJ HI Ll LJ U Ll IU
i © X oj qq © g
■ © © — — oj eg
• © © © © © ©
. © © © © © c»
g ui
u. u.
o o
© © © © Oj g 0J —
ojgoj »-©©©©
© © © © © £> © ©
©©©©©©©©
— 01 g Ui Ui i '
«• © © © © ©
© © © © © ©
© © © © © ©
©©©©©©
ai © — eg Oi -r ui ui r~ mi in © — eg cn g iri ‘ 2 i n oo c> © — oj oi g ui uj h- «o m © t- ig oi g in ui h- a® ai © ■»- eg (*■, r. «o cn c> r- eg
— — — — — — — — ^ — oj eg eg eg eg oj oj eg eg eg eo co oi oi o"i oi oi oienoigggggg g ggginuiininininuiuiuiujui
©©©©©© ©©©©©©© ©©©©©©©© ©©©©©©©©©©©©©©©©©©©c>©©©©©©©©©©©
© c> © Z> C- -I’ © © © 3 © © © © © © © © © © © © © © © © © © © © © c> o © © © © © © © © © © © © © © © © ©
©©©©©©©©©€•©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©
0« a© IT) © »- (g 01 g Ui
Ul 10 Ul N r- N N N N
©©©©©©©©©
©©©©©©©©©
©©©©©©©©©
Number 25
□ r. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
223
W
O Ll
z —
_1
Q 0.
UJ Z
UJ ~
z u. :
2 ) _) c
T- o CL X P
cl '.o o u » :
Cl # >C Cl * <
Z lii
Ul ->
CL CL Z J
O O <1
CL CL Z >
CL CL O
UJ Ll it Z
lL O
Z lL Cl
- o o z
<r <r
Cl Z U CL
Z O CL I
o *-* o
O h UJ Cl
ltd DD
j <r z
• o — e>
: c cl in
- CL Z
: i-
. z cn cl
— L)
> CL I- Cl
i cl " <r
J Z CL I-
: o u <i
Cl 00
; z i-
> ‘UJ z
: co z —
: uj uj o
J v CL CL
c <r cl
J T. J Cl
. UJ lL I
<1 CL l
a o
Cl cl I
_i o <r o
d E > Ct Q
Z~Cfl — h-
UJ CL UJ CL UJ
Z CL Cl CL (3
cl in — cn — ou
co in - cl - cl -
* .L T- CL <S> Cl a
z <r
•a I
UJ o
in i
in z
uj —
CL i
Ll Q 1-
_!©*-©
iz -a oo a
UJ
I U I <
O <1 o
1 t* h Cl I- in l
to * © m r> v <
• I- # o # ■:> fi ;
10 CM U'i Cm CM
x oq <r
CL — O O
CL O O
uj <e a
0 . 0 * * * l
- uj o a
■ z z UJ
- 00 ~ _J
CL CL i
cn in •
CO Hi l
J tr'i fiCi CL it CL .
i cn ci o'i o cn :
J J _l fci UJ CO C
oo o o oo
0 <J O (J
U_ Ll L L
oo n in r- co n o'i co co uj co c>j co in n t r- o
‘ *1 O’ -I Cm -I
ClClClCluJCLClCLCL
in CvJ CM C'J *t P: in CM -
in o'i oo — cl u: — in
i <i i _i m <r -d d cn <t in u uj _j
cn a cn (/- i lj Ci cl a oo ci oo uj :x z
Cl. -j Cl-IUOO_JOO_l_l_J_JClOOOCL
0 CL h-
(0 W If) fJ
CM (0
C l— l— 0 .
to cvj to cvj <o c*j co uj to in
<S> If) t- co cr>
O Cl <1 Cl
) — ci uj 1T1 uj ci — t- cvj — co — <j> in lo
- © in in © in oo © © co © © © id co uj co m
i © Cm © uj
ai oo ci u. c»j rt
lL u. lL u. © ©
r* rt <* in in
© © © © © ©
to r*» « cr» o
to co co co *r •*
C'J C'J cu CM C'J C'J
© © © © © ©
© © © © © ©
f'- CTl 00 C' 'l — CO N <1 Cl II C'J rt N <T» 00 Cl II
©©©©©^-t-^^ — ^ CM CM CM CM CM CM CM
in ifi u*i in uj in uo in in u") m in in in in in iri in
©©©©©©©©o©©©©©©©©©
1- CO 00 N
co CO n in
in in if) in
(Si © © ©
■* <r oo o a il © cu co
U'< U'i U’l If) U”i Ifi (!'• Uj co
U') U'i U'i Ifi Ifi Ifi Uj Uj U'I
©©©©©©©©©
CO rt U1 Ul N 00 (X) © T- C'J CO >t Ul CO !•' <1 IT) O T< w n U Ifi III N «j (T) C> T* (U CO CO !•- 70 CTl © ■-> C'J (0 *T Ifi Ijj r~ ti
rt rt rt rt *t »t «t in in in in in in in m in in to ui u) u> co tu to tu cn u> r-» r- n r* i - r- r- oo *;• a «o oj oi «j ©
(M CM C'J CM CM C'J C'J C'J C'J C'J C'J CM CM CM CM CM CM CM CM CM CM CM CM CM CM M C'J CM C'J CM CM CM C'J CM C'J C'J CM CM C'J CM CM C'J CM CM
© © © © O' © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © © ©•
©©©&©«>©©©©©©©©©©©©©©©©© ©©©©©©©©©©©©©© ©£>©©©©©
<f ll' Hi I
ID 10 CO «•
u'i u'i in in
© © © ©
Di U li. n 10 CO OU 00
(ilfidiNNSNN
U'i Ifi in U'i uj U'I U'I U'I
©©©©©©©©
N f-
u j in
© ©
© — CM 10 rt U'i CO f» od CTl © t-i i;m Ci * ifi UJ N oO CT) ©
CTl iT> O’i CT) CD CTl CT) CD CT* CT) © © © © © © © © © © -r*
CM C'J C'J CM C'J C'J C'J CM CM CM CO CO CO CO CO CO CO CO CO CO CO
© © © © © © © © © © © © © ©©©©©©©©
©©©©©©&©©©©©© 3) © © © © © © ©
u cn ©
z in m
UJ I UJ
I U'i
o a
Ci iL
D
UJ CL
in UJ
CL I
Z CL
a cl
CL UJ
a >
a —
- z
o —
<r >
<i u
o Cl
o ‘ •
z uj <r
■2 U'i a
CL Z Cl
z z
i U CL
I CL Cl
y. x
Ul UJ
Q Z C
uj o <r
— Ul C _!
• (OXlL
: a a ;
uj o
> UJ U! ■
i in ao
<r —
: o l-
- Z (Cl
UJOdX
ci co <r cm
z x + h It O h
2 - co ui u. r u'i
CL © fti ‘K-UJUJt-
Ifl O.Ul Ci
h- Z UJ Z UJ Uj
Z CL d U I IL IlI
D Cl r (Ij U U'i # I-
cn cl
o z>
ZlL f ‘
Ul - <3 Cl
I EL d Ifi
I— O d O i—
Cl X CL
u. <r i/ i
U) 01
CL CL
a u'i
a oo
<r _j
_i <t <r -a cl
<i Cl i- »- _i
— _j cn cn o
: -1 d in il) 1 (l C* c* i Cl l-
) O U! UJ ftj ill <»j Z Ul ftJ Z J
I J J .J -J J U U 01 _l !_| 01
UJ Cl' © CL <T
U'i L 1 ul d l/J d CL Ul
tr 01 Cu © |jl V- L Z
dJJJJlflUiU
O X Cl <
co a u i <i <r
Ul 00 Ul Ct
oi o oo o oo
Ci •_> o o u
IlIlIlIlIl
UJ CO CM CO (Jj CO
in ai uo uj co r t r> co
O'I f- U'I to U'I 0J CO
CTl f- Ifj © 00
00 © ©
m- <r -a
© U U_ © l
© U_ U'I © l
in ui
•t ’t
© ©
M f* d U l
(Il (Il CU (jO c
•* '
© © © © <
IT) m Q II
n t~ r~ c-
'J ^ 4
© © © ©
10 U’I
«0 oo '>0
tT M-
© © ©
r- O'i •_> ui ©
CO 00 «j flO CTj
rfrT'T't’t
© © © © ©
CM t Up 0 1 I Cl 11 - CO if oj -I
CTi (J' (Tl CTl (D CTl ffi I <r <E -I •!
rt- *t rj- rf M- rt -t rt M rt
© © © © © © © © © © © ©
o u co m oo -i o
•ll <3. 00 00 00 01 00
rt rj -t 't *t «.*• rt
© © © © © © ©
UJ CM Ifi N
OO L> O L>
't rt rt *t
© © © ©
CT‘ 00 t_« Q Ul
O U U Ul II
rt »t rt rt rt
© © © © ©
I 00 ff) © T- C'J co ’j U'I 'll I - ii CTl © T- CM 1.0 t Uj UJ N oo ffi © T- CM CO rt U'i Ul N ul Ul © t- CM CO rt U'i 'll r- © .
i oj al oj O'i CTl CTi CTl CTl (Tl CT) CO (Tl CTl © © © © © © © © © © •— t» — t- t- -r- t- -r* CM CM C'J C'J CM CM CM CM CO (
i •< T- t- t 1 r" - - - - n - r* OJ C'l W C'J CM C'J C'J C'J C'J C'J CM C'J C'J CM CM C'J CM CM CM C'J CM CM CM Cm CM CM CM CM CM I
• © © © © © © © © © © ©©©©©© © © © © © © © © © © ©©©©©© © © © © © © © © © © ■
'©©©©©&© © ©©©©©©©© © © © © © © © © © I?. © © © © © © © © © © © © © © © ^, ,
Page 30
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
224
z x
— Id
<1 I
^ X *
+ UJ Id
X I >
w I O
•• Z E
~ o
Cl X Z O'
Z W in
a (x
cn id o
Id (f’i I I-
O Id t-
<3 Ct O J
ino o
in ci -cl
id © in t-
e z z
X It o
Q UJ => O
Z X K
id uj in
© ct cl
m id
h- in cl u.
Z 1- U 1ft
— o z
Id ISi
Z K
03 CL
Z X
- UJ
© x
a a
Cl Id
E 03
U _J
O'! X Ct o'. O'
x <i in j in id in
in Id ftj 3 co z t—
0_I _l CL _J OJ CL
r z
o o
a z •
II CL
in u
in z
in CL u.
III D II
_l Q
O Z
u ©
>- z :
3 o a i
Q. Z Z
X X
Id Id (
X X I
_l X X
3 Id Id
EXT
aoci o © o
O 03 ■.< 13
o o o o
II IL IL iL
x cj n I N I
*-©xx©-©_ixx©ct
zz - * z z z in - - z o
in cl cl in cl cl a
xincain-im~CLCLain~ cl & on a a. cn
inoaci03303E_i_i(t03Ein£ti-(LrK
a.Jjja.juooMjttiiBocfia)U(£
z o
o
“ X
O z
*- h- — X —
I O') *3 K o I
Id Id Id Z Z Id
> I— ►- > 3 <X CL
O E Id O O Ct
E I 13 E O iIj
w a e >- is
Id 13 15 + + » - UJ
I— Id CL X 3 *• O 03
r3m * - * i e 3 ^
x in >- in
<TZ3j-a<r<rid3CL
IdlflCiODl-UJZjr
J0L_IJJCnjO3CL“>
I E —
I ©
H E
: Cl
) <1 O
. Id CL
C IL E
) ^ 3
: n z
i CL
. in 3
z K
J Ct Id
: 3 ct
J Id ll
'ft —
CVJ f-
M *********
id cti co kd o co
(flnwniiinnaiNnpKOMninnw-t
maicjj'taimiricocxiai
* o
n *t
m m »cm-.
& oj —
Q -r-
s ci o s ci a
^ «i o - o y
N CD
U. U.
in in
> - cvj coin
i Cl O'! CT) CD CT)
> co co co co cn
co s «o cn
m m m cn
co co co ci
© © © ©
© cm m c
© © © <
Uj Uj (LI I
© © © <
V- CVJ CO
© © ©
TJ
in UJ N
© © © ©
V
© © © ©
«t
© © © ©
© © © ©
* * *
© © ©
© © ©
L--^*u>cncauj©(vjTtioa»oaciii_'~<oin
~*NCMCViN(VJNCOCOCOCOCOCOCnCO***
IftlfiCOlftlftlftlfllftCftlftUjlftlftlftCOUjU)©)
©©©©©©©©©©©©©©©&©©
« m © h Nco^incDNoo(n©'r<cvjcoT»'inu)NoO(n©'—
»- , *-CVIPJN(VI(VJ(VJCVJC'JPJCVI(OCOCOCOCOCOCOCOCOCO't *t
©©©©©©©©©©©©©©©©£>Q©©©©©©
©®©®®®©®©©©c®®®©&©©©©©©©
mauuw’tuMtiau
**«*inininininin
IftlOCOUJUjCDUJUJUJUj
©©©©©©©©©©
co^-ina)Noo(r>©»-cvico^in
^'t^«t5tTt^inininininin
©©©©©©©©©©©©©
®®®®®®®®®©©®®
u. CVJ
in id
Uj Uj
© ©
N SO 01 © ~ rrlTlUiNcO
in in in in tu id id id id id
>» -f 1 « 'J Tf >» Tf
© © © © © © © © © ©
© © © © © © © © © ©
CL >
Id O
> E
I UJ
>
X o
© Cl
-J
O 3
J- O
Z Z
1 —
in in
Id o
© u.
© -
CL 03
w in »
• Ct 3
Ct if*
oa in _j
Cl Oj 3
- O Ci -
Ct Z Z Cl
a uj uj a
(3I3EI3
Ul Id 13 Id X
03 a. Cl <Vj O
X Ct X X
a in -a cl ©
td 03 UJ E _l
j J j u m
in in
Id Id
J- Id Cl
EX —
h- cn
Ll Z
© UJ “
in
h- o o
Ct _J z
a u —
i- z J-
in id in
Id
Ct X
u -
cl in 3
‘ t ‘
KUO
in <r © uj
y M3 l
j— in u i o
E I fti E
XXX
•1 <1 (L in
UI id E -J
J J u 03
o zat-
z x <r o iu
Ul O O Cl O
x >: cl-
cl - a h i a
e *x Li m u.
u m j j m
O 03
U U
II U.
ci cl w in
z <i v
UJ O E Ct
03 © K
<3 X Z Cl
Z E O
- O E Z
13 Ct UJ UJ
Id II X
cn i
i in .
© o
Id Z
03 UJ
cn l
uj in 3
13 UJ Cl Z
Ct -
o Cl Cl 13
Z O Z Ul
Ul *3 <3 03
13
a —
K <3
cn uj
> K
a uj
in o
•3 in x
- z -
03 — <VJ
I Ct <3
in tf i uj
Cl 03 _j
O u
Z Z CL
— Xld-
L. X I 13 03
It Cl 03 O 3
cn Cl 3 3 3
03 _J in 03 Ci.
03 UJ
u
O <1
cn ct
K 3
Ll O
K C^ Z >
Id U. Id O
> - Z <3 U
<1 X O (3 UJ
cn in •• •• a © it
XX -r* cl
x a 3 3 u Id 3
in a in o uj z 3
Cl J J (t © 03 Cl
J CO
: in ct
i z Id
1 ct iL
c 3 in
K Z
: Id a
j ct Ct
E > © © ©
- O I— Ci z
# e x in a. x —
© o in x cl in ct
cl uj i © cn u cn
E 03 in UJ 03 3 03
U -1 ft_13 0_I
in co cn N- co ai in n co n co cn co co
« ***** Cu
iftNinc-inmcooo
W N ML N n N
********- —
CVJ N Id III CO ID CO
03 *i flC'
U"> IT* U J
© © ©
«j © Cl — CO
flti 03 CO CT> CD
in in in in in
© © © © ©
— CVJ ri Ift r- 00 CTi © — ig CO rt ifj
■r- — — — T-,- — CVJOJCUCVJCVICU
CO CO CO CO CO CO CO CO CO CO CO pj CO
©©c© ©©©©©©©&©
©©©©©©©©<■©©©©
U"l ffl U LJ
J) ff) (Ti (Ti
ifi in u'i in
r» u ffi ©
CVI Csl (VJ CO
CO CO CO CO
© © © ©
© © © ©
© fu rt o.l 0:
© © © -I ©
in ifi in u*i in
© © © © ©
Cm co o ID (L
co co co ri cj
C-J CO (0 CO CO
© Cl © © ©
© © © © &
id in
© u
if j in
© ©
© T.
*t «*
CO CO
© ©
lftaj©Old©CU*fr
U O O O O Cl Ci ill
ifj in lt ■ ifi if. ifi uo u-i
©©©©©©©©
Ift 00 © U UJ iL ^
Q Q Q Q a Q Ul
in in in in in in uo
©©©©©©©
co^uiicin.ooiTi©^(Mco*3i/iccii'-«3ffiT-(vjco^tifiiftr-.floin©'r-
't^'t^'t^^inifiininifiininininifiioiouiiftiftaiiniftiftNN
CO CO CO CO (0 CO CO CO CO CO CO Ci CO CO CO Cl CO Ci CO Cl CO Cl CO Cl Cj CO CO CO
©©©©©©©©©©©©©©©©©®®®®®®®®®Q®
©©©©©©©©©©©©©© ©©©©©©Q®©®©&®&
Cl UO ai 03 U. CVJ rf
Id UJ Ul UJ Ul U. Il
in uo uo uo lo m uo
©©©©©©©
tO-»UOILN*iri&T-C'JD 9 lDlLN
NC-NN-N-Nh-oOcOflOoOoOoOoOoO
CO (0 CO CO CO Cl CO CJ Cj CO CO CO CO Cj CO
©©©©©©©©©©©©©©©
©©©©©©©©©©©©©©©
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 31
225
z — o
o — in
o <i
Id 00
_j <r z
ki a
IiOI
I Old —
a u_ cl a
— u. a a
cl o _i <r
© ao x
u_ cn - w
» » * z r~
♦ * # o #
<1 <r <r <i
Ci a a. oo a in
ZOCJCt-
<r <r cj oo <i a;
N N N fl N ^
CVJ X
I- - X
D w Id
oo a —
Id Z —
O Id U
a oo oo
X X X X X :
o'; cl oo <r
: i a: in j it o:
l GO GO 03 D (tj 03
i a. oo _j a. oo _i
00 00 oo U Q
K — CL Cl
Z 00
- - T- O
<r a
Id CL Z t-
I- *1 O 00
<1 Z CO
i- u t- in o: tt
O 00 — Z Id UJ
z <r z >
— Id © i— i— o
lOI-ZlilOU
h- <1 Id Id Id Z Id
OO 00 13 OO I— <1 CL
OO X »- + -r- X
i- - x d x a *
z <i * o - cl <r
Cl 00 Ct 00
Z <T UO I— J J
r* W Cl 03 ICl (L I>
a 0 _I _l I— OCi Cl
XXX X Cl *
Q <1
0. /-
<1 -
Q Ci
* * CL Cl
00 <t
00
CL I- — CL
II Z UJ
•— I— >
Id O Z O
> (L — CJ
00
(L l
Cl CL
NicinMOinMc
n xr ro od m ffj
CL <1 CL
(J Q -
: t— cl x
CL OO X 00
o z a a: j
in id in j
l- CL _J 03 CL
in cr> n <i
o oo
a id oo
0. <J
oo a -
a. <i
Id oo o
z o
o oo a
Id Id I-
CJ CJ <J
<E a Id
(L CL CL
O'! OO OJ
CL IL CL
X X X X X
I- — CJ -I
z Z U .1
d <r —
o <i i- z
o I- D , CL
a Z Id CL =>
I- C “ Z Ol¬
id O it O O Id
00 _J CL Q _J CL
Cl 03
03 <1 t»0 <_i Id GO
aciooidZi-
j j j a oo cl
o o a
<i a id
CL a. Cl
00 O O Id
X CL Hi CL
cvj cvj cn w co *
(J • _l
o © o
•a it
<i u.
ZUlL
— O —
<r
CL CL
<r a <r 3
Z JI - PO
O O U Id Z
a a
UO Ll CL o z
z u. o r —
Cr. Lt LJ u I
_l CO Z I—
(J 00 OC CL
X X X X X -
m rt to oo <r u
o cj o o cj cj
Ui CXl CO CXI CO 'JO
Ci © O S Q fii
N CO (D © r- w
** * * in tro i/o
in in i/o uo in in
©©©&©©
© © © <s> © ©
QiLT-ninco«o u.
uoaaaQCaa a
( 0 ( 0 ( 0 ( 010 ( 0 ( 0(0 uo
©©©©©©©© ©
’tinuor-oocns)-r-Mc r J^inuoNoo»-(Vin»tinuo
inirjinirjininuououoaicocDuouocoNNNNNN
uo in itj in in m in in m tn in in in in in in in in in in in
© © © & © ©©©©©©©©©©©©©©©©
©©©©©©©©©©©©©©©©©©OCiSi
— co in oo a o
Id Id Id id Id id
CO UO CO CO CO CO
Ci Ci & © © i
«o(ne>T-cypoitin
NNoCioCioOcOoOflO
ininininuoininuo
©©©&©©©&
©©©©©©©©
Id © * UO oD <1
f- oo cn © t * cj
« o oo co cn cro in
uo uo in in in in
© © © © © ©
©©©©©©
01 0 )
in in
© ©
Id © CVJ UO UO ao
lL © © © © ©
Ci N N N N N
©©©©©©
CTi 'I CJ Id
© © © ©
n r- n [■-
© © © ©
N«m©»*N(n^inu)N«o(?i©T-N m men © © t- w n ^ in
ITl(n(n©&&©©&©©©&T-r-^r-r.T-^T<lMWWW(lJ(-J
inuOUOUOUOUOUOUOCIiUOUOUOUOUl CO 'JO CO CO 'Ji CO CD <Xj CO UO CO CO UO
© © © © © © © © ©©©©©©©©©© © © c* © © © © © ©
©©©©©©©©©©©©©©©©©©©© © ©©©©©©
CL O
a z
Z CJ
CJ id
O Z l-
ctl J id
<1 II CL
Z Z © Z li- Z _J
UOW«)UWNOI-r>3
D _J - x z JUJ -
izo-d# — <r*z#'d©
zuioi3<iinocittiiLiuain
inai-y. odDczwrziui-
CLJUOldJJUJCEinOOQJCL
uo cro z
<L _J CL ■—
<i -i - <r
z u. r ©
o CL id r
<lu.lt
Z Z IL <1
Id (J — UO iL
Z Id 00
Ol-l— J
Id _J IL D
z o a _j >-
i- i- o z
u y in in z
If i GO Z Id 03 D
- id h- IL <r u.
II
ZD IL
(J - (J
U D Z 0.
inwzuwin -
Id x j x - ©
# o ii o o d r
oo
03 (J OO
Cl Id O Cl O Cl CL
zzaridiLZ
O 03 (J OO I-
r u
cl <r <r
«i uo
a a
<i a
— - z
u (J CJ
<r cl id uo
a z. z »-
J O 03 IL
z <r <r
uo CJ i-
Q- _j uo
X uo
cl y- —
o o a
•»- U_ Q_
>- IL D
03 + O iL
“ a o z
> q <r —
— Id
ci oo on
X - X
X © X
X T- X
X X ©
X X ©
X X ©
© <1 CJ -
z z - x a
CL - Z Z h-
uj o x u. a
*- oo (j - a
_l X
<1 Id <t U CL <1
> — ldO —
<1 O Z O CJ
n I/J <1 u J <1
OO D D
D D
‘ N in O T- Q c
> Id CJ I— <1 U <1 (
I Q I- D -• I- — l
• © d o undo:
'IOuUu*Ou(
UO 03 CL cn
:hOLiiacici<iinj
! irt Ii 1 E 111 ill Z UI U- 03 ©
I I- OO © il J <1 40 m J CL
<r a c a
IL Cl CL CL
cn uo g o in
_i _j _j _i
UO 10 10 N W (0 N OJ UO OJ C*0 rt *±
XXX— xxxxx
in CVJ O- N O' N
XXX**:
> D D
I o ©
i n po uo in n oj n cn n
XXX****:
ni/oNinft3i©©oj'<tcxico<r<j
UOClOUOUOUOUONNNNNNN
CO CO UO CO UO UO UO UO 'Ji 'JO CO UO CO
©©©©©©©©©©©©©
mo»*ftjn^iouiMCi(n®f
UNNNNNNNNNNoOcJ
©©©©©©©©©©©*©©
©©©©©©©©©©©©©
a u.
n n-
co co
© ©
i- cn in n
a3 «0 a3 03
ui CO Ui CO
© © © ©
cn rt uo co n od ao
co 00 aO 03 o3 <0 aO
^ ^ ^ "t
©©©©©©©
©©©©©©©
q © cn in
03 03 00 OO
CO CO (JO CO
© © © ©
m ^ i/o co p* oo tr>
on 0i oo ao 0) 0) 0i
^ Tt * ^ Tt
©©©©©©©
©©©©©©©
co co <r
00 00 00
CO CO CO
a u. w
oo ao a
co co co
CtONyfO^NNSbO
ao co cvi co cn id o m <i cn
*co«<icju.rvit(O0>o
<r<ra<i<r<rQ3iLiQ3Q3oa
uo CO '.0 CO UO 'jl CO CO CO CO 'J|
o ai oi w oi qi ©©©©’©©©©©©'©
'-(vjcn^uocoNco0)®T-cvicn^-Nco0i©T-(vi(nTfiricor-'ao0)6>'r-cvjc , o
©®®©©®©®©T- — — ^-cucvjrviccjMcucunjcvicvjcncncncn
uoininuoinuouoininininuoininuiinuoininininuououoinininuoininifj
©©©©©©©©©©©©©© ® © ® © ©©©©©©’ ©©©©©©©
®®®©©©©®®®®©®©iS<S>iS>iS>©©©®©©©©©0©©®
Id U. © —
03 03 (J CJ
CO (0 CO CO
® ® © ©
in<ONaCi 0 )® — (VJtnTtUOCO
in in uo ui in uo uo uo uo uo uo uo
© ® © © © s © © © © © ®
©® ©©©©©©©©©©
Page 32
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
Number 25
226
00
. a y-
O — i/\
CO <E o UJ
</* E • H-
id cu r
13 13 •» o
3 3 0 w
OS OS © l/> CL
XXCC'DD
UJ UJ UJ Q J
h- t- /\ r ll
x x >
x x >
x x >
x x >•
x x >
XX >
XX >
X X >
XX >
XX >:
X X >
X X >
XX >
X X >
X X >
X X >
XX >
XX >
XX >
X X >
XX >
XX >
XX >
XX >
XX >
XX >
XX >
XX >
XX >
XX >
XX >
XX)
XX >
XX >
X X >
XX)
XX >
XX >
XX >
XX >
XX >
X X >
XX >
XX >
XX >
XX)
XX >
XX)
EfOUJOJ XX)
o H O x X >
E 'XI — m|XX>
□o ll viy x x >
PCC‘ 30 XX)
Zm 'X' lit O XX >
•ro os ujo o x x :>
ix r- > o x x :>
I .. on.. OJ X X >
or z: xx)
O- .. K— .. XX >
30 cs 13« x x :>
uixi zzujz xx
I/M UJ DOS UJ XX >
0. ■=• XX)
y E =
XX
XX
XX
XX
XX
XX
XX
XX
XX
XX
XX
X X
XX
XX
XX
XX
XX
XX
© «— ©
J
©-*©
O O 00^4
|i.OQ O O O —
□
(too- o o
ft;
UJO-«o -.©©
I
Zl —oo © O O
Iooo ooo
K
►_o O O OO—i
©
--ft
o VI
oo
DO
fio
ro
<xoj
E ~ LL
DO
OO
E © © © © ©
<Z © © o o ©
a. ooo o
| .. o o o o
or
313 MMMU
uj uj r r r r
I/'OS UJ UJ UJ UJ
ooo oo o
to® o o o o o
a
do o o o o o
UJ
fto o o o o o
ooo 00-0
ooo o o o
CO
CO
UJ
LtO -4 eg o — CO
l—<•_ 1 O o ooo
1=10 o o o o ©
IOOOX (JUUX
—
o X
O' X
O X
•M X
> OJ O' X
:• * X
J .. O- X
a x i
bj :
E I
X 3
cor
<r z (i
X -J
<r _i
uj <i
z i
v > us
ot iL u.
<a <t u.
3 3“
U U
. X z
. uj a:
I- 3
IUZZO
> “ “ o
<1 O a: UJ
cn a. a. a:
U » — (VI a x
<i >- i 3 a u
“ q u + o “
o <r z in z u 3
<i <r <i <r a a
(Ll-J(LI«I»-ltUaUJ<IbJ
zvuLBJuwsaviuozQU
3i-aj_ia._jo_ias_ios_i_i
3 3“
u u
z z
co (vj as us us r« n n <j n md
<l in
it JZ
OVIK
U_ Z 3
o as uj z®asosc3<iasii-as u.
Z ‘X O * Z * Z * Z - Z N Oft
“<ru o#— *“•—#— #*
: as as as as as as u
HLOIlVUIOIL-VSiSMOV)
r jeji JI3DZI-KI-
(oasuasuaiuKiKiaitOK
■ x x in o x
« K « X » •
Ct “
Cl & Z
<1 UJ
(O Cl UJ
a. e
E E 'J
O O CL
Cl O ■_
+ os a: as
x - Ul '
•> © > M
N E
CL CL
UJ UJ
> >
<l cn
Cl -
a. 3
Ntocvjpscvjcnc>jcocvicvj>
x us x a i x u‘. 3 x a.
<r 3 <r ll cl (LtscuoavK as
U'C'lUJ —JOE —I UJ Z UJ UJ OS U. I—
jo— iL_>ujuas_i“as3_ii-CL
STj US CTj eg ui US Ci US fvl CO 0< OS 'jj -
o as
o o
u. u.
> ■>* as a a>
It U) S (T) (J 1U
— (vj to ao as
(VJ (Vi w fvj (VI (VI
NNNNNN
® ® © -S»
USS«0(T)O“('J( r l'»USUSN«S
(u (vi (vi (vi as ps ps ro n ps cs (o n
Ui US 'JS ‘jS UI UI CXi ‘X US VO U> 'JS us
•S €> ® © < O C> ■S* © <3 O
(vi cn
r- n
© ©
«t t
u> us
© ©
© ©
* *t
CD UI U)
© © ©
© © ©
US N aS ff) i
t t t t L
Ul Ul US UI c
© © © © <
© © © © <
as as o
© © ©
— cvi cn «t us
us in us us us
ui ui us CD us
© © © © ©
© © © © ©
U. - CO iri
cn ^
NNNN
© © © ©
us r- « as
in us us us
Ui CD US CO
© © © ©
© © © ©
r- in
(•> N
© T-
CD CD
CO CO
© ©
as Ci i
^ T* '
r
(vi as ’
CD CD C
CD CD C
© © <
- as in ul¬
us in in [f i
a- r~ r- r-
© © © ©
<c u © ■n u"i »•- in as a ui ©
US US (D UI cO CO CD 10 CO CO N
n n i-- r-. r - r- n n n n s
©©©©©©©©©©©
US oCi (T) & ig as *t in f"» cO fft © “ (VI i r i rf US CD l-“ gS iTi © —• (VI
US Ui Ui I- N f- N r- N N N I- oj «S <Cl uS aj uO D «J aj aS a> at <Ti
CD Ul U- *X CD CO CD CD CD CD Ul CD CD CO Ul CO CD CD CD CO CO CO CO CD CD
© © © © <S> © <c» o © © © © © © © © © © © © © © © ©
©©©©©©©OO©©©©© ©©©©©©©©©©©
t N Hi
N f- N
f- I- l «
© © ©
as * us
jj os ai
CD Ui Ui
© © ©
a as
N uD
O' N
© ©
N «S
ai a>
CD us
© ©
© ©
© ©
© ©
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 33
227
TOTAL ERRORS 00000
TOTAL WARNINGS 00000
S 8 EDITHA
A REVISION OF THE FYLSTRA KIM-1 EDITOR PROGRAM
BY H.T. GORDON
College of Natural Resources
University of California
Berkeley, CA 94720
Dear Jim, Tom, etal., Received: 78 April 3
I am herewith submitting an extensive recoding and
enhancement of the editor section of Dan Fylstra’s SWEETS
program for the KIM-1, published in (and copyrighted by)
BYTE. It poses several dilemmas of general interest. First, the
problem of program names. SWEETS is Fylstra’s acronym for
2 main programs, that share some subroutines. The entry label
for the editor (the only one I have worked on) is CMD. I have
given the more descriptive name EDITHA to my revision, on
the grounds that its coding is mostly quite different and that it
includes some major innovations (address information and
modification capability, greater error-protection, and a richer
command structure with modes not found in CMD). It is
clearly an enhancement of the kind that Fylstra himself antici¬
pated would grow out of CMD. I hesitated before adopting the
name EDITHA, since renaming can easily become an idiotic
game, involving personal vanity, causing confusion, and even
trying to disguise software theft. I have restained many of
Fylstra’s names in EDITHA whenever my recoding did not
involve a major functional alteration, both as a courtesy to the
originator of the basic concept and as an aid to comprehension
by users. One of his subroutines (DETLN1) is an inefficient
way of determining the bytecount of a 6502 opcode. In
EDITHA I have replaced DTELN1 logic by the decoding logic
of my subroutine BYTCNT (published in DDJ # 22), with
minor retailoring to fit the special context. / re-use the name
BYTCNT for this trivial modification, because I think it is
better to extend the meaning of a subroutine name to include
minor variations, instead of endlessly coining new names.
There are, alas, no rules defining how great a dissimilarity is
needed to justify a new name.
The second dilemma is the perennial one of software
ownership. I assert copyright (qualified by a special non-
monopolistic free-diffusion clause) for all components of
EDITHA not either previously in the public domain or copy¬
righted by someone else. Exactly what these are is a moot
question. Very little of the original CMD coding is left intact
in EDITHA. None of the alterations is anything but junction¬
al (i.e., there is no intent to evade existing copyright by mere
recoding). None is copied from any work I have had access to
(although since there are relatively few ways of doing some¬
thing efficiently, it is not impossible that some coding is an
independent recreation of already existing logic). Here is the
qualifying clause: The intent of my copyright is to remove all
impediments to free diffusion, including (to whatever extent
my copyright gives me leverage to do so) impediments that
others may wish to impose on enhanced or different imple-
Page 34
mentations, including systems other than the KIM-1. I ther-
fore authorize any and all uses (including copying in any form,
publication in whole or in part, and commercialization) if (and
only if) all software associated with the EDITHA coding is
declared to be equally available for totally unrestricted use.
What I am trying to ensure is not only that my copyright will
be no bar to progress but that it shall serve as an aid to it.
Perhaps this is Utopian, but there’s no harm in trying! It
would be a tragicomedy if micro software had to be diffused
underground, in the style of Russian samizdats, as a response
to the censorship aspects of copyrighting.
The third dilemma is: where should revision of a program
published in BYTE be published? First, let me say that I con¬
sider BYTE a valuable journal. I have had a note (on 6502
opcodes) published in it, and a second one (on a pseudoran¬
dom number generator, 8080-coded) is accepted and will
(eventually!) get published. There are some advantages (a
small remuneration, glossy paper, and a very large readership)
and some disadvantages (among them are: loss of all rights to
your work, and often long publication delay, and no indica¬
tion of the date of receipt of articles). On the whole, my
relationship with DDJ has been a more humanly satisfying
one. Friends have told me its title is zany (but to me it’s
whimsical -1 reserve zany [and its synonyms j jor a world with
tens of thousands of megatons of hydrogen bombs poised for
launching). But publication is prompt, always includes date of
receipt ( a fine ethical touch), and the author retains the rights
to his work. These small-is-beautiful qualities compensate for
inexpensive paper and no remuneration!
Sincerely,
H. T. Gordon
The SWEETS machine-language editor program CMD,
created by Dan Fylstra (Feb. 1978 BYTE) is a major enhance¬
ment of the KIM-1 SBC. However, it has some coding inef¬
ficiencies, logic errors, and other limitations. The major ones
are its inability to allow manipulation of addresses (only pro¬
gram instructions can be seen in the KIM display, and the lack
of adequate safeguards against user errors. It is all too easy to
ignore the CMD error-warning and cause disastrous upmoves
or downmoves of immense blocks of RAM, including the CMD
program itself. My revision gradually became a major overhaul,
involving drastic alteration of both the main program (whose
entry point I have renamed EDITHA) and the subroutines.
Insofar as possible, EDITHA (version 1.0, intended for the
basic KIM-1) is located in the same memory areas used by
CMD. This conforms with Fylstra’s intent of leaving a large
block of RAM free for new program construction under editor
control. However, the enhancements provided by EDITHA
increase its length to 478 bytes (71 more than CMD), and its
subroutine READIN had to be located in 0200-0234. This
leaves only the 459 locations from 0235-03FF free.
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
228
The revision relocates the original CMD pointers in zero-
page: MOV AD (to DE-DF), BEGAD (to E0-E1), CURAD
(to E2-E3), END AD (to E4-E5), and adds a new one, LIMAD
(at E6-E7). This allows operation of a new guard subroutine,
INLIMT, that protects memory locations outside preset pro¬
gram limits from being moved or overwritten. BEGAD is
redefined as one location below the program start (lowest)
address. LIMAD must be set 2 locations below the highest
address that the program can enter. BEGAD and all lower
memory locations, and LIMAD+3 and all higher memory
locations, cannot be altered or moved by EDITHA. The guard
subroutine blocks the action of the DA (delete instruction)
key unless BEGAD < CURAD < ENDAD. In addition, it
blocks the AD (add instruction) key unless ENDAD < LIMAD.
When these conditions are not met, the only effect of pressing
either key is to display CURAD in the usual KIM address dis¬
play, and EE in the data display. CURAD is the address of the
instruction currently displayed, that EDITHA is refusing to
add to or delete. The same message will be displayed if any
hex key is pressed when EDITHA is in the command-entry
mode, but in this case the EE does not signify that CURAD is
out-of-bounds but that hex keys cannot be interpreted and
are being rejected.
Although EDITHA has instructions that allow the user to
alter BEGAD or LIMAD, they are normally fixed and define
the program limits. As in CMD, CURAD is advanced to the
next higher instruction when the + key is pressed. However,
while the + key is depressed, EDITHA displays the address of
the next instruction (that appears when the key is released).
If this address is within limits, 03 appears in the data display,
but if it is out-of-bounds, EE is displayed.
During program writing, CURAD does not change, but
ENDAD moves upward when AD is used to insert an instruc¬
tion and downward when DA is used to delete the instruction
currently in CURAD. If deletions exceed insertions, ENDAD
may move below CURAD, and thereby block the action of the
AD and DA keys. This is no problem, since the user can press
a hex key to see where CURAD is and then use the pointer¬
resetting instruction to set ENDAD to a higher location. In
fact, it is sometimes useful to set ENDAD to the program start
address, so that the user can explore anywhere in memory
with no risk of altering programs by accidental pressing of the
AD or DA keys.
The operational changes in the + and DA key actions are
achieved by quite trivial modification of the original (much
less informative) CMD error-message, together with continual
supervision by the guard subroutine. Users may notice one
more trivial change: one-byte displays by EDITHA are of
normal brightness, while those by CMD are extremely bright.
CMD refreshes one-byte displays 3 times as often as 3-byte
ones; this may or may not shorten the life of the LEDs, but
I found it unpleasant. Therefore EDITHA inserts a very brief
dark period in every refresh of a one-byte display. Both CMD
and EDITHA display two-bytes at about 1.5 times normal
brightness.
Implementation of Complex Commands in
the AD and GO Operations.
Unlike the + and DA operations, which are simple com¬
mands executed by pressing one command key, the AD and
GO operations require complex commands. Both call sub¬
routine READIN, since the user is expected to key in more
information. Although much more complex than its equiva¬
lent in CMD (subroutine RDBYTE), READIN also calls sub¬
routine SCAN1 twice. Unlike RDBYTE (that always error-
exits if a command key is pressed), the first call to SCAN1 by
READIN will accept either a hex or a command key, the lat¬
ter causing a return for interpretation by the calling routine.
If the first key is hex, the second call to SCAN1 ignores all
command keys but returns when a hex key is pressed, insert¬
ing the completed byte in the leftmost display (all others
blank). ADKEY logic interprets this as an opcode; if it is a
one-byte opcode, it is inserted in the program and the oper¬
ation is over. If it is a two- or three-byte opcode, READIN is
again called so the user can complete the instruction. At this
point, it is possible to press a command key and cause a
return. In version 1.0, EDITHA interprets such command-
hex-command instructions as errors, simply wiping them out
as if they had never been keyed-in at all. In an expanded
version, however, more complex interpreting logic could open
a cornucopia (or a Pandora’s box?) of special commands. Very
few of these possibilities are realized in version 1.0. One reason
is the memory limitations of the basic KIM-1. Another is that
I am not sure how powerful a machine-language editor ought
to become,or what operations will prove to be the most useful.
The AD Key Operations
Pressing the AD key has no detectable effect if CURAD is
within limits and the instruction currently in the display is
one-byte. If it is two- or three-byte, it is left-shifted so that
only the previously rightmost byte appears in the leftmost
display (all others blank). When the opcode is keyed-in, it
replaces the displayed byte. If it is a one-byte opcode the
instruction is complete and written into the program (and
being displayed by the program-scanning subroutines). Pres¬
sing a hex key will cause the usual error-display of CURAD.
If the opcode is incorrect, it can be deleted by pressing the
DA key.
If the opcode requires 1 or 2 operand bytes, pressing any
command key will cause an error wipe-out (a quick way to
erase a wrong opcode). If a hex key is pressed, nothing will
happen until a second hex key is pressed. If the opcode was
two-byte, the second keyed-in byte will appear in the
middle display (normal order, an indication that the whole
instruction has been written into the program). It can be
deleted by the DA key. However, keying in the first operand
of a three-byte opcode will cause the opcode to shift to the
middle display and the operand to appear in the leftmost
one (reverse order, instruction not yet completed). Again,
pressing a command key will cause a wipeout. Keying in the
third byte (second operand) will cause display in normal order
(instruction written-in, deletable by DA).
A peculiar “double-command” operation is also possible,
executed if the AD key is pressed twice (pressing AD, then any
other command key, has the same effect but the AD-AD is
safer). The effect is to insert the single-byte in the display
(following the first AD) in the program, “completing” the
instruction. The AD-AD operation is useful only if the instruc¬
tion in the display before the first AD was a one-byte opcode.
It allows duplication of this opcode, a convenient way to enter
a string of one-byte opcodes (00, 0A, 4A, EA, etc.). The
AD-AD was not a planned feature of EDITHA, but an
accidental consequence of the planned GO-AD (to be
discussed in the next section), retained because its implemen¬
tation requires very little interpreting logic.
The GO Key Operations
These represent by far the most complex EDITHA enhance¬
ments, that still are only a minute fraction of a legion of pos¬
sibilities. The only “double-command” is the GO-AD (the
other 3 possible ones are interpreted as errors). This sequence
of 2 command keyings resets CURAD to the program start
(one location higher than BEGAD). (Note that, although the
command keys are read by the KIM monitor subroutine
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 35
229
GETKEY as hex numbers from $10 to $13, the RE AD IN
decoder subtracts 4 from these values and returns command
codes from $0C to $0F to the GOKEY routine.)
All other GO operations require keying-in 4 hex bytes for
completion, the first 3 appearing in the display one after
another, in reverse order. Wipeout can be caused by pressing
any command key following entry of any byte into the dis¬
play. The terminator byte (not displayed) is the command
code that will cause execution of a special operation. Since all
non-interpreted command codes cause an error-message, it is
useful to keep the final key of this code depressed so that it
can be seen displayed. If there is no error-message, the com¬
mand has been executed. Error-messages are always XX 04 EE,
where XX is the command code that could not be executed
(except for codes 04 and 08, where XX is 00). The following
is a list of the 5 valid command modes, with their codes:
Mode I, code 00
This is the ERASE command, that restores the original status
before the GO key was pressed. Although the “wipeout”
feature of command keys (a later development) makes it
unnecessary, it might be useful in later versions.
Mode II, codes 01 to 03
These are IDPR (insert data into program) commands, 01
inserting only the first keyed-in byte (rightmost in the dis¬
play), 02 the first and second, 03 all three. Before completion,
display is in reverse order. When the command is completed,
the inserted bytes will be displayed in normal order (as with
the AD operation) but interpreted as data. Thus the sequence
of keyings: GO-08-18-28-03, that is displayed as 28 18 08
before the command code is entered, will be displayed as
08 18 28 afterward. This sequence would need 3 separate
entries in the AD operation, since all the entries are one-byte
opcodes. Also, the entire sequence can be deleted by pres¬
sing the DA key once (if there has been an error).
In both CMD and EDITHA, to add a new program or data
sequence following the one in the display, one must first press
the + key to advance CURAD. This is necessary to allow the
user to see in the display exactly what he has entered. In the
EDITHA IDPR Mode II, all bytes that will be entered (and
with codes 02 and 01, some that will not be) are visible in the
display before the command is keyed-in, although in reverse
order. Some users may wish to implement an automatic
advance, so that more data can be entered by the Mode II GO
without having to press the + key. This can be done by replac¬
ing the BEQ DACMD at 017B by a BEQ STPKEY (F0 37).
The disadvantage is that one will not see displayed what has
been entered, and not have a second chance to delete an erron¬
eous entry.
Mode III, codes 05 to 07 and 09 to 0B
These are program SEARCH commands, with some kinship to
the GO operation in CMD. There is unnecessary redundancy
here (05 = 09, 06 = 0A, 07 = 0B) that saves a little GOKEY
interpreting logic, but could be eliminated in expanded
versions if codes 09 to 0B can be given another useful inter¬
pretation. One major difference from the search GO in CMD is
that searching is done in the range from the current CURAD
(the address of the instruction that was in the display before
the GO) upward in memory to ENDAD. To search the entire
program, one must first reset CURAD to the program start by
a GO-AD. The reason for this modification is that the same
instruction may recur several times in a program, and the GO
logic in CMD can only find the first occurrence. When using the
EDITHA search GO, the user should keep the final command
key depressed. If a match is found, the display will show the
address of this instruction that will be displayed when the key
is released (while the data display will show the number of
bytes that were searched for). If this is not the one wanted,
press the + key and redo the search GO to find the next
identical instruction, higher in the program. If there is no
match, the operation will display the ENDAD address,with EE
in the data display.
The second major difference from CMD is that EDITHA
can search for only the opcode (code 05), for the opcode and
one following byte (code 06, identical with the CMD search
GO), or for the opcode and two following bytes (code 07).
E.g., the key sequence GO-85-FB-60-07 requires that an 85
FB 60 sequence exist in the program. This happens to be the
terminal program sequence in the KIM monitor ROM. An
interesting test of searching speed is possible if one sets
BEGAD to 03 FF, CURAD to 1FD4, and ENDAD and LIMAD
both to 1FD5. When EDITHA is entered (set address to 019A
and press GO) it will display the RTS ($60 at 1FD4. A
GO-AD sends it to 0400, and 0404 is displayed (although of
course there is nothing there in the basic KIM). The GO-85-
FB-60-70 keying sequence will darken the display for less
than a second, then (with the final key still depressed) display
IF D2 03. This is the addresss of the last 85 FB instruction in
the ROM, that appears when the 7 key is released. Nearly 7K
of (mostly non-existent!) memory has been subjected to a
complex search in a reasonably short time. If one uses the 06
command code to search for only 85 FB, one can find 5 recur¬
rences of it lower in the KIM ROM than the terminal one.
Mode IV, code OC
This works exactly like the GO-AD double-command. It was
the awkwardness of resetting CURAD to the program start in
this way (or in another way possible with Mode V) that led me
to develop the GO-AD. In the original CMD design (largely
retained in this pioneer version of EDITHA), keyings are
recognized in 2 different ways. CMD calls the program-scanning
routines that maintain display of the instruction at CURAD
and detect a depressed key, which causes a return for interpre¬
tation by CMD logic. Hex keys are rejected (an EE EE EE
error-message being displayed while they are depressed), while
each of the 4 command keys causes control to shift to a
special routine. With more elaborate logic, one could interpret
double-commands here (or even, if one were ambitious, triple¬
commands). It would be a cleaner way than that in version
1.0, which re-uses the scaffolding of a primitive approach to
implement a more sophisticated one (just to avoid one more
reconstruction job).
The second kind of key-recognition in CMD is done by the
GOKEY and ADKEY routines, via subroutine RDBYTE,
which error-exits if a command key is pressed but accepts
keyed-in hex bytes. My decision to implement double com¬
mands here was based on the fact that I had already included
a lot of command-code interpreting logic and it was very
simple just to modify READIN slightly. When I started out to
revise CMD, I did not have a clear idea of how it worked and
never dreamed that it would go so far! The structural flaws in
EDITHA (1.0) are the result of its just growing like Topsy,
with its growth halted when it started getting too big for the
basic KIM-1.
Mode V, even-numbered codes from $10 to $8E
These are IDZP (insert data into zero-page) commands (64 in
all), that write the first 2 keyed-in data bytes into contiguous
zero-page locations specified by the command code. E.g., the
keying sequence GO-12-34-10-10 will cause $34 to be writ¬
ten in location 0010 and $12 in location 0011. Before the
keying-in of the command code 10, the first 3 bytes are dis¬
played as 10 34 12 (reverse order); this is wiped out by the
command code, since nothing is entered into the program.
Since the effect is not visible and one has to be extra careful
with zero-page, the third keyed-in (and so displayed) byte
Page 36
230
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
J
must be identical with the final command code that causes
execution. If it is not, an error message is displayed while the
final command key is depressed to indicate a total wipeout.
Because important subroutines are located in zero page
(0080 to 00D4), command codes 80 to 8E skip these loca¬
tions and write into locations 00D8 to 00E7. E.g., the
sequence GO-1C-00-8A-8A resets CURAD to address 1C00
in the KIM ROM, causing display of the instruction there.
This program can then be scanned by the + key, since
EDITHA does not object to its user going anywhere in mem¬
ory just to look at it. Before wandering around in memory,
ENDAD should be reset to the program-start address (easily
checked by a GO-AD), using the 8C (reset ENDAD) command
code, to “disconnect” the AD and DA keys. Codes 8E (reset
LIMAD), 88 (reset BEGAD), and 86 (reset MOV AD) will be
less often needed, and the 3 lower pointers (80, 82, 84) are
available for future enhancements.
Some General Commands on the Listing
Since EDITHA interacts with molasses-slow human opera¬
tors, it is not designed for speed but emphasizes coding
efficiency, error-protection, and convenience. One major sub¬
routine (ASCNIT, 0100 to 01 IE) is not listed because its
coding is basically identical with that of the Fylstra-BYTE
copyrighted CMD (located in the original at 0103 to 0121)
except that the downward relocation in EDITHA requires
that the 3JSRs to SCAN3 be coded as 20 IF 01 instead of the
original 20 22 01. The relocation is functional, since the
JSR DETLEN that is the first instruction of the CMD sub¬
routine SCAN is now the second instruction in EDITHA (at
019B), so that the third one (JSR SCANIT, labeled DACMD)
can be branched to to cause a display not interpreted as an
instruction. My omission of SCANIT may strike some readers
as ridiculous, but the intent is to avert the wrath of whatever
gods EDITHA may offend! It also underscores the reasons for
the free-diffusion conditions (spelled out in my covering
letter) attached to my own copyright.
Listings therefore start at 01 IF (SCAN3), that is signifi¬
cantly modified in order to reduce the brightness of single-
byte displays (the JSR ONE just kills a little time). To be
punctilious, I note that the terminal coding of the EDITHA
subroutine MVDOWN (00C9-00D4) is identical with that of
the CMD subroutine ADVAND. It seems to me that the logic
of adding an 8-bit number to a 16-bit number is so commonly
used that it is in the public domain.
Since keying in 478 program bytes into a KIM is a head¬
ache, I am willing to tape EDITHA for KIM users who would
like to try it out if (1) they mail a blank cassette to me, with
a stamped self-addressed envelope that I can return it in, and
(2) they agree to inform me of any flaws they may discover in
operation (after checking the RAM to make sure the listing is
correct). Regrettably, I can not be responsible for any failures
of the U.S. Postal Service, and this approach will not be usable
by users outside the USA. The taping will be in the standard
KIM format (slow but sure) in 2 sections: 0080-0235 (index
01) and 1780-17E3 (index 02). I am not eager to do this
hundreds of times, but fortunately this is an unlikely event!
Comment on Enhancements
As I have indicated, EDITHA has many possibilities for
restructurings and new operations, and everyone is free to do
whatever he or she likes. It is quite possible that someone has
already written something as good as or better than EDITHA.
More likely, every further revision will have some fine ideas of
its own that ought to be in the ultimate version(s). Perhaps
DDJ can serve as a clearinghouse for pooling these ideas, and
thus hasten development of a super-version (that will merit a
super-name!).
ta
P M
>>
JO Tk-—
< t>»
HCi cj
•H M
ft ®
O 0473
Sh M
M 9
P 03 E
03—M
® -p
-p W-
OT — 2
w o
EhMEhI
£h O 2
«=fc20
fc Q
rH
s
<
o
'hfc^fcpH
co
rH
M
§
§
sz;
o
O
o
Eh
O
CO
CO
O
CO
o
ta
-- rx O'
P c~ .—- 73
Si t>> 9'-' 9 ^
bO ^ d 73 ® P
3 fflrl OP ID S->
O PH!) !»M S Xt
03 D»> 03 Q .JO O 4 -<H d
n-H o E p 3
03 73 +3 O d o
® 43 3 K O O <Vh
+3 ® Si ® ® O
>» MO C fl
JO — 43
.—.
— ® ®
-P
p
---
C- O.
Eh tCM
03 — d
>H
73 O
r-x p ® XI r'
ctf U
®H ft
3 ^.
d
C-* O M d P
-P O
B n
p 2 a
o
■P
cd K
XI Q 0 3
03 43
aJ C
t»»q hh
p
•H
E ISI
dSDtJO
•H
u 3
JO o
c
X
E Q
a) <Jia l
O TJ
b 0 O
o p->
•H
<D
O M
E ® ®
-P ©
O
-d- ®
o
E o p »3 a
Q.J3
o
EUs II
W
2 ISl
M
X=tfc
Q Eh
Bas
ogo
— MO
43
a)
E
O
c
fti <! k c
W Q Q
Q < M <<
>H >H WK X C < K OT
a &4S=COQQEHOEH
OOhi 4 ijnbK
939 s5
o m m p co 1
si ia
O' C '~&4
COHfOW O' rH CO
pqeatao'tac'-j-CM
_d-tatata cm O' q ia ia
^OPCM <d <JOO CUvO
rH <*VLT\CO «! O pt, CM
M CM CM CM CM CM CM CM rb
r~i r~i r-^ HHHHH
taraca ea ea ea ea ea ea
atK koto
^ 2 W 2 WOTOTOO
-ThhCOffl
E-i
S
S5
O
o
caN
ea M
W
o
K
Si
OT
Eh
u
OT
W
Eh
ta
ia
10 tacM p''£>
1 w h
weai
ta
o
o 43
0
60
Si Si
o
-te-M
=tfc «
K OT
£ &
o m
CM
ia
ir\f"\*a q c'-o'
K C'-aOCO w sO
vo ta h oraao c eaea<& ts.es. ea
C.jJPQQQOOQ&.CMCMCQO'
c^um— O' o w fc cacM-d-r~ <: o
r-\ ro rb (A nx ox ox _d-_dCd-pd-d- -d-
rlHHrHHHH HrIHHHrl
eatataeataeaeataeaeaeaeata
-d-<ea
eawa
K
eaiA
o <4 oQ <o ea q
taeaux iacoj-
tA
M CM
cm'O ta
<aJcO CM
co ta
■d K
O' ea
O CQ
O' eaea <d ea<aea
O O' QcO Q CM ra
WiacM
-d-lAMN
UX'O
CO <•
o wtacM cauxcd
XAMX
UMA
in iavO vo no xO vo
rH rH rH
M M
M M
M M M M M M M
ta ia
eaea
eaeaeaeaeataea
Eh 03
O &> K m K 2 ft)
SOO O M C
Q K X K Q >
-«e-2K — k a q
w CQ <3
£3 O W < W K OT
SOS^SOTO
0 camEHCQ bm
JO CO ® »
ta ft k 03
d o o ®
•rl •> 43 K 1 >»
d_d" ra —
pea—W
®— OT
ft X — W
— K W O
OQ K
<AK ZpJ-o!
KM W
X^OT
Q O’ ^ OT
ZWHwO
<; CQ OT O CO
O
«
oxfc CQ_d-#4
ea-d-WeacQ
cMaiAcaea
CM K co o CQ
<< o pqeacM
vO 'O 'O c r—
M M M M M
iaraea*ara
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 37
231
'"'A
A CSP
d-'-'CS X
aX ©
COOT
•H CO •»
•JQ
t» X <4
© © X i
41 si p
I •*<{
■PHp
<D rl <JP
bOol I O
M £ ©H 05
P W-HO
<4 0 — 05
WO 05
05 < W
d
O
^ JJ
43 P
d tj
• a ©
c
•H O
-P
©
43 41
•H O
d a)
I* 33
£h Eh
M M
£8
CM
CS
CSCS
IS.
CMCS-4
W W CQ
©
43
® P
O d
© S
a
OT o
43
D.
d m
®
C
P
® 43
43 .H
t>>
33 ®
43
P
d d
-—' <p
C 43
® t>>
<-.43 Xl'-'
0.43 d
d-H 43 ®
41 d XH
O S ® P
■h C ©
0 . 1 -t o
-h
d 43
X 5
p *
© to
0 ^
A ©CS O
ax>
•H
K A
0
© « 1 k
—=tfc
— *
d cs— d
(25
p
d
d II Eh d
Js CO
>H 3
O PA
0 w
^ pH
<M <d 05 ®
P EH
cstwp
— P O d
& h.
. 2°
— Eh —
M
CO
ffi G^X P 05 C?
co W W P co W
>-3 m p m t-s m
Eh
(X.
W
o
o
<4
05 X >h <4 <4 >HX W to
copggEnSS^^
toHpn«
«
cs
cs
Cd
o
Eh
CO
IS
cs
1-00 CSCA OJ
i WCSW w
e'¬
en
cscsccsescs
cm W o p cm W
(OvOOCMDW
QppqpQ
HnHnrlrl
CSCSCSCStSCS
CS M3 CSCA HCO <4 cscs
oj <<<!CQO'oopvO
cs o-\tr\o- <4 o p pqcs
wWWWWWWWW
r—I p p p r—I H I—t p p
CS cs csts cs cs cs cs cs
®
43
t»»
x>
p
-4
w
05
®
d
P
43
d
o
d
XI
d
OT
d
o
Ch
bO
c
P
■a
o
o
o >»-'
43 cd cs
P cs
x a
OT II
43 p
© TJ 5
OT—- O
— c
CO
W XI
P Eh —
>H
=«fc cq
X X X
P EH W
P CO P
55
M
p
si
05
to X
®
-X'——- ®
>• 43 d
'-'A >»P o
X OT ® 43
d 3d ® ot
o
o d
<4 ®
x>
p
to
d
CQ *H
© <M X
> ©
© TJ XJ
co aj
© -P a5
d d o o
a)
- « d O
n o 43 43
— © © ® a p
d — to— d d
OT d
X—- d
P IS Eh W A
p 55 p W P ®
55 <4 H54d
HDWWH —
X co=*fcco X=te
X 05 Oh O X O CO
Eh CO S O P P EH
co a> o m p co k
s >
<4 -4 <4 *4
a. op
S pcaPS
WfePPWP
Eh <4 -4 Eh55
S O-60-W P
C0=tfc05 C5X
PPPP^KPM^XCXtHWKXXWcO^Ppp
m m rn m c-t m r 'i nr. c-i ^ rrs c-t r\. c-i p 1
cocOcOcOFhcOSoKQEhSz;
C<:cccoh>oPOPcOH
QlztcOEcdlaEc^SSSS
«
CO
Ox
M
«
co
CL,
o
s
ca
cs
mocsiAnj-
HtSPCSWCS
cs
CA OCSCA OP O'
WCSP W WWW
cs
cs
I CA-4-CO
Icsoo W I
PCS
ww
OJ P
W cs
P CO
cs w
OJ p <4 PCSO'CSP O' cs <4 <4 «4 <; vocs O' cs CAP caco j-cscs p -d"Cs cs -koco vpcs
<! co ocoojo 0 '«; wp cscs cscs co nop cs<|0'|iq^pw®HP®^H co p
PpfCAA-<| O WCSCM cO-d-lAvO b-O' O W CSCM J^O ^-CAP W>SW4S(M d-CAt^
CSCSCSCSCSCSCSCSP P PHPPPPPP(MOJMN(M(\l(\|M COCA <aSco CO CO m
PCMCM0JCMCMC\1CMPCMPCM<MCMCMPPC\|C\|C\JC\)CMPPC\|CMCMCM P rPC.p. ic.41
CS CSCS CSCS cs CSCS CSCS cscs cscs CSCS cscs CSCS cs cs cs CSCCS CS cs cs CS p p p
O'-
,—. 1 —.
p
OT 0- .—
XI
s
O, ® .—■ ©
*»
C-*
O A © A
°l
T)
P--' A ©
0
^ ©
d d A © -a
©
a|
-P fi
O s P TJ
>
•H U
P X to
0
TJ
X *H
o
® p
d
O X
43 o
OT —■
® ® cd
43 p
*p Oh
O d OT
d s p
-T3
CO !Z!
W EH p P P
W H C EH S
EhSI>hu
>H M P W C
P P <1 S P
43
<lH
®
A
OT
d
W
fc 15 Eh
co O 3
K P
»KO
=tfc W P
OT
®
•P
a
© TJ
— >>
0 ^
TJ ©
d
© ^
^0
•H ©
O |>>
O
TJ
h-hCS
-p a
O aJ =
d
O ©
rH rH
top
© 0
CU rH
d
B TJ
/a /A
®-60-
rH -“-TJ
0 a
©
O
41
© ©
©
rH O
II II
II
TJ £ ©
p *H
d
<4 a
X
, O
X TJ
3
E O
© to
>H TJ
©
© ©
XJ ©
W -P
d ® =
A
O -P
41
p
0
© ©
to
c W d
0 —
d
TJ bO
+ O
§3
Q 0 3
p 0
'—
W CJ
0
—^ p
d
aJ >5 Eh
® W p
P P a
o H 5
— WO
P CO
CM W tHCSP >H
P X W P <C W
P 5 > S3
-60-Eh O-60-p P
P <tf
P W P
W Eh C
> P >
O p P
S W <5
cd © -—-
43 OOP d
cd h—' © ® o
'd - 33 ot xJ 43
S boo p
w d o p © ot -a
Wpp £ Bp ©
tO>H OT
© OT
P to ©
a © d
OT P X)
p a.’a
TJ m ©
n to to o
ra © © 43
®P^
da 41
'am©o
n p p ©
© TJ P jo
ItrjMfi.©
" 2hB
h x « p
o P x P
ip n jq w
c- cs
W ^cs
o P
P O
© X 43
43 ©
P OT
d «43
JO®
- d OT
CO
Eh P Eh
P C 55
s > 5
p p 0
P < o
C « O « Cf
EH CO O CO W
MbWrjffl
NOP
0Hcoaw«coppoxc<i<:c
SoStztcoocoap i| Q Eh P Eh
OWOWWPQ alB^H JtOiJtO
CLD
JSR
JSR
Oh Cf CO Oh O O’
S W 0 S 0 w
0 « m 0 m m
Q5 CO O
CO O 0
bnffl
JSR
LDX
LDA
BCS
tH>HX<405Wc3^(i|oX
pIhEhEhcoSw^oEh
3wnMbWfflr,®M
HICMD
NOaDD
EDITHA
DACMD
GCMD
>H P
W <4
s >
Oh a
Eh 5
CO
ERROR
INFORM
ERR1
ADKEY
C P
P CS
csp
cscs
C^
p
P-
P
W p-
H P
co W O CS W
W P CAW P
WCOCQJ- P CM CO CAP <4 cs
ao caW ca <A csca WStWcs
cscs
COCS
cm W t^cs 0 w
P CS -4 P CSP
CM CO (A
CQ WCS
Q CM cACM
CO W WCS
WCA<|CQWCQW(!l,vO<;
WWWWPWOqwS
CACSCSCSCS
CO OJ O' CM W
CA CSCAtS «© cs <5 CS CA 4 1ACACACA
O « O Q4WCSP® 4 <JCA-aJ O'
CO cscs
P CM CM
O'CSCS O'cscs
0 w m 0 caw
CSCSCS
CM 0Q O'
CSsO 1ACS
CM <4 <4 m
ca«4vo CACscscsts^tsvO
<4 COCO co CM p W cm OHOO
-4-A O' CQ W
c-— c-— c— t— c—
p p p p p
cscscs cscs
cs
CD
p
cs
P fAlA 0- O' <j| O P W P OJ^tvO CO
COOOCOCOCOCOCOCOCO O' O'O' O' O'
P PPPPPPPPPPPPP
cs cs cs cs cs cs cs cs cs cs cscs cs cs
<4 « W
O' O' O'
p p p
cscscs
P rACAf— O' CQ
■© ■© Hi *© <3 <4
rH rH H H H H
<4 m cq
p p p
cscscs
J-P-CAffl
m m cq cq
p p p p
CSCS cscs
QWP CACACO <4 O W p
mcQoooooooQ
PPPPPPPpPrH
CS CSCS CS CS CS CS CS CS CS
Page 38
232
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
is.rvi'-'c-
H TSlrH
(\l m c\J
II
®f-a m 3a
-P -P
03 03 tfl-H .p
•H .p 0 X> -rl
•H ® X>
x! XIH fi
■P -H >>
bO-P « a) H
3 m 3S». -P 0
® ®Tk ® n
H -P X
®
C!
cm 3a o
x! oj a
-p x>
bO 03 bO'
C! -p C
® -H CD
rH a rH
•i 0 •
03 -h 3a
® aj II
>».p
® Eh
Eh X -H
W &•'—
W O' rH rH
« O HOIAW
o ® x
o to ®
-P .p ® aj H
•H *H 43 rH
X X >>-P ®
® ® X tI O
mcM ® ® o
> > -p
a a a! al
43 43 n oi C
® ® CO Eh -P
Wg ®
X
o
03 O
>H 2 *H Eh WPh CtfQ W
qOQHgSWfcg'
§
XI
Eh
g
EH
£5
O
£
m
isflpaegg
|OCQ<!DQI—IHC0C0D3
. WOH
IN
a o
i H
X>
®r^
«o
2
•HW
S II
032
•PS
rH-P
rH C3
•H 0
sea
® 2
m X
•h o
a ®
-PTJ
§
s
S3
O >
wo
P 2
•h E
* ® a)
> X
03 O to
tH E o
X! Eh
•P Q.
P
2 > w >
> tao Eh O
O S^S.
s=fc^pa —o
CO
X SX <y< WOWX^<<H<IXWiH><OWO<JiO<lOOC0
QSH^gWWHQQQEEaQPHOgHlQqEOSE
aHfflHBQQwaaaMonacjcQmoa^toBHK
c <xx <y<*
9 "
Px
o
O
o
w
Q
Eh
M
re
g
2
O'
TSlCVJHrHCOtStpqtx, mtr\rHUMAOJ
3a wisicDTaojTa.O'tar-itsitsna.ta
CO 2
W(9
<K» H 3 a 0 3 a 0 ' 3 a 0 ' 3 a 0 ' 0 'ta 0 ' 3 a® ®J-_ 4 - 3 a
2 P32CMPOWCMPCMOWC\jWO O®® M3
\A
tst
Oj W
aq
W3aW® WtMOferqt H-
PtaPWPWWPWWW
p±®-3-CM\A
w war --
I raw
lAW-d-
W Q W
\AU\M3® 3a23a'£> 2 M3 3arH_4-r-l-4-3a J--4-3a3a® 3_r\U\lntaM3 3a
2 co <$ w woo Qooco<*m<i;o'WQ2uo'QrH<<;^ocoo'W'X>
3a oj^t^o O'® p w rH oqu\o-cx m qpqwHn
CO COCO CO COCO COCO 0'0'0'0'0'0'0'0'0'2 «:
J-vOCQ
2 2 2
2«QW§ni <r»XAt^O' WOWrl o^lAt— O' 2 o Wtacj-0-
2 22 2m«ninmn«mnouoouooDoqq
©
X
*—^
4-i —
o
©
r—^
X!
0]
— ctf
r- X
d —
X
bO-^
M
P w ctf
-P X
c u
o
C“
—-H X
o
•H
•H ®
•H ©
X
ax!®
©
s
X TO O
X
-P *H
X
O -P
bO H
si
>H
© *H rH
® «
C rH
®
•H
XPH
o
II
O erf
<D X
a ® ®
T3
£
U 'O -P
X n
O O
•*
-P ©
03 O
•rH
O Crf TO
O XI
p»
©
x> ®
^ ©
X cd
•» O
X
rH ^
a x o
OJ
•H
U *H -P
X
TSt-P
X
© O
<D^ -P
xsix
© si —
® Oh
'ti.
3
T3 d
E
9k «
1'——'
■--
— a
o
--—
®
Eh +
O p 3
I H *P
i cr, ®
u
O
>H CO
Eh Eh
£_ .
HBK
M
O
t—C
W
co^j-ta
O® M3
OBOEh 0=ffcCQ
0 2 0 2
o9 q -
S + Eh + > + Eh >< -
“ “_4n — > S co ti >
0 o m w w o
2 P Eh CQ 2
«
M «
XI W
2 co
o
S5
2
>
Q
2
XJ M
WXI
K !z;
CX xi
3
%
w
Eh
Eh
H 3 Eh
2 4J ®
M ® ®
XI Eh rH
S'— O
M
CO O CO
Eh XI EH
« O K
EH X
II
2 «
IH W
XJ
CM CO CM CM (HVJ-rH
w w Wta waw
W w co ta W'OtA
Qtata w Qtata
03
w
2 Eh
M W
9g
a p q co 2 2
2 2 2 w > >
> a > EH ota o
o a o >h 2 2
2 0 2 CQ'-=jfc»^
Q+ &h+ + Ohi_, _. .
o2W S 2 WO —r
Eh +
-BW^W
co
o
o
-p <
C
X
3
-P
®
X
X
o
M
M3 W
S
^fcM
K O >H |k| X >1 <>H
COOEQEQQQ..„
bmcOXcO japcOH
pH Ph
t> O
W O
> XI
O Ph
2 O
X-
t—I
coxMMWcowaw
O'CM Q w P W Q 3a Q
2XWoxw>h>ho<;o2cooop><w
EhSSSPhSQPhOXPQEhOWWEhQS
cOMOHOinPOCOEHCOcOcqpcOcxXlCC)
0 EH w
S W eh
a
o
M3
tarn
co3xv3x\3A3aM3c\i\Aao\A3a3a3x\\A3a3a2 23a3aoota
rH M3 CO 0'W2m2QO'PmpO'WOOQMDHM3
CM W-3-Q W3X\b~- cOH-r^lXc
isiqwwqww wW3aw
3 a3aja3 M3 _ 3 -rH 3a rHco taM3p±3a j-j-ta 2 ixuA3aM3co3a oj §
(MO'CO«jco<!m20'WPWWQ2o O'® w® m o 2 Q
O'2 O QW5C(M4®®20Q&HH<H3U3XO'BOQ|i ( 3aH
cococo ®® O'O'O'O'O'O'O'O'O'2 2 2 2 2 2 2 2 2 m m
c c c c^~t" c c^~*c— c^-c"— r— C' c^-— c—— c^-— c s --c''-c^--r^-c—c^-c'—
CM IA t—O' m Q W rH ®3X\M3® <| O W 3a CM _43X\ p— O' 03 Q W fc H
mmmmmmmooooooooppQppppppPM
c— c— c— c— X'— r— r— r— x- t— c— c— c— x- c^- c— c— rxc^-cX-rX-t^-c^t—
i —I H r—Ir—I i I i—I i—I rl —lr—I i—Ir—li—I H I—Ir—I i—!r—I i—li—I rl i—I I—If—I rl rl
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 39
233
PRELIMINARY SUBJECT TO REVISION
IEEE COMPUTER SOCIETY MICROPROCESSOR STANDARDS COMMITTEE
PROPOSED STANDARD for the S-100 BUS
PRELIMINARY SPECIFICATION
BY GEORGE MORROW
Thinker Toys
1201 -10th Street
Berkeley, CA 94707
(415)527-7548
and
HOWARD FULLMER
Parasitic Engineering Inc.
P.O. Box 6314
Albany, CA 94706
(415) 547-6612
The following is a preliminary specification for the comput¬
er bus commonly known as the S-100 Bus. This bus was first
introduced by MITS Inc. with their Altair kit. It has since
spread throughout the electronics industry and beyond. Today
over a hundred manufacturers make products which claim to
be compatible with the S-100 bus even though, until now, no
complete specification has been available.
This document is a specification for both timing and signal
discipline. Signal discipline is described using the Bus Master/
Bus Slave language long associated with Digital Equipment’s
PDP 11. This point of view facilitated the development of a
simple and highly realizable DMA protocol, the extended
addressing capabilities, and the 16 bit wide data path
proposals. These extensions to the original Altair bus represent
a significant advance in the state of the art of small computers.
These advances are a direct result of a continuing dialogue
with a large number of interested people who have contributed
their thoughts and ideas to the standards committee.
S-100 Bus Signal Definitions
Bus Signal Notes
1. There are three types of signals on the S-100 bus. M stands
for Bus Master. Signals designated by M are those which a
Bus Master must generate. The Bus Master currently
controlling the bus has the responsibility for faithfully
generating all signals of type M during the duration of its
control of the bus.
S stands for Bus Slave. A Bus Slave need generate only
that subset of type S signals which are necessary to com¬
municate with Bus Masters which have the ability to
address the slave.
B stands for Bus. Any bus signal which is not of type M
or S is by default type B. This is not to say that some Bus
Master is not in fact generating one or more type B signals.
Rather a type B signal is one that (a) not all Bus Masters are
required to generate, and (b) not any Bus Slave is required
to generate.
A Bus Master is, by definition, a bus device which gener¬
ates at least all of the type M signals. A Bus Slave is a bus
device which generates some subset of type S signals. A
Bus Master may also be a bus slave and vice-versa. Memory
devices are almost always Bus Slaves while DMA devices
are usually both a Bus Master (data transfers) and a Bus
Slave (accepting commands). Central Processing Units are
usually Bus Masters.
2. The 8 status signals are: SME MR, S INP, SMI, SOUT,
SHLTA, SSTACK (not specified), SWO, and SINT A.
3. The 6 command/control sig nals are: PHLDA, PSYNC,
PDBIN, PINTE (not specified), PWR, and PWA1T.
4. The 16 address signals are: A15, A14, A13, A12, A11, A10,
A9, A8, A7, A6, A5, A4, A3, A2, Al, and AO.
5. Data output is specified relative to a Bus Master. By defini¬
tion, data which is transmitted by a Bus Master is always
data output and occurs on the DO bus.
6. Data input is specified relative to a Bus Master. By definition,
data which is received by a Bus Master is always data input
and occurs on the DI bus.
7. A bus cycle is a collection of bus states (BS a ). A bus cycle
always starts with a BS! state which is followed by a BS 2
state. After BS 2 comes an indeterminate number of B^
states. A bus cycle may have zero BS^y states or it may have
an arbitrarily large number of BS W states. BS 3 is the bus
state which follows BS W (or BS 2 if there are no BS W states
present). BS 3 is followed by zero to three BS, states. A BS 3
or BS; state terminates a bus cycle.
8. The DO bus is the followingset of signals: D07, D06, D05,
D04, D03, D02, DOl, DOO.
9. The DI bus is the following set of signals: D17,D16,D15,
D14, D13, D12, Dll,DIO.
10. These signals should be generated by an open collector bus
driver capable of sinking at least 20 ma. at no more than
.5 volts.
11. During the last half of bus state 1 and the first half of bus
state 2, the DO lines are used to furnish extended address¬
ing to slaves that can utilize this information.
For 16 bit masters and slaves, the DI and DO lines gang
together to form a 16 bit bidirectional data bus with the DO
lines forming the low order byte while the DI lines accomo¬
date the high order byte. The con figuration of t he DI a nd DO
buses is governed by the signals SXTRQ and SXTN. When
both these signals are low, the DI and DO lines become bidirec¬
tional. Otherwise, DI carries the data to the current master
while DO carries data to the addressed slave.
Signal Characteristics
Bus drivers must sink at least 24 ma. at no more than
.5 volts. Except for open collector drivers, they must source at
least 2 ma. at no less than 2.4 volts.
Bus receivers must have diode clamps to prevent excessive
negative excursions. Any bus signal less than 0.8 volts must
be recognized as a logic zero and any signal more than 2 volts
must be interpreted as a logic one.
Receivers are to source no more than 0.8 ma. at .5 volts and
are to sink no more than 80 jua. at 2.4 volts. The capacitance
load of an input from the bus must not exceed 25 pf.
Bus State Comments
BSi is the initial bus state of a bus cycle. The address lines
are in a state of flux during through most of BS t and PSYNC
is active starting with the second half of BSi.
Page 40
234
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
.PRELIMINARY SUBJECT TO REVISION
BS 2 is the second bus state when address data, status, and
ready signals become stable.
BS W states occur as needed to synchronize a Bus Master
with a Bus Slave which has brought one of the ready lines
false.
BS 3 is the data transfer state when a Bus Master transfers
data to a slave or vice-versa.
BSj is a state during which the bus is idle.
Timing Notes
All timing references in the timing diagrams are specified
at the midpoint of the rising or falling edge of the signal. Rise
and fall times are not to exceed 50 ns.
All signals referred to in the timing diagrams are S-100 Bus
signals with the excep tions i n note 6.
1. The falling edge of PWR must occur within the area shown.
The rising edge must occur within a similar area of the next
Bus State.
2. BS^ is either BS 2 or BS™,-
3. Addresses, Data, and Status signals must remain stable
during BSyy.
4. The interrupt lines must be stable for the period shown in
the Bus State preceding BS! of an op-code fetch. The pro¬
posal is that when an interrupt line is true, it remains true
until the CPU responds. Normally, this response would be
an I/O instruction that addresses the interrupting device.
5. The rising edge of PWAIT must occur within the area
shown. The falling edge must occur within a similar area
following the rising edge of the logical AND of PRDY and
XRDY.
6. Signals prefixed by “DMA” refer to internal logic of the
new Bus Master. These signals control the buffers of this
Bus Master which drive the Command and Control, Status,
Address, and Data output Bus lines. The timing diagram
depicts logic levels which are high when these buffers are
disabled.
7. BSo is either BS 3 or BSj.
8. BS!?, is either BSj or BS! .
9. Extended address bits A16 through A23 are multiplexed on
the DO lines. They must occur as shown within 250 ns after
the rising edge of 0 2 during BSi. During a write, data must
appear on these lines 100 ns before PWR is active. The PWR
signal can be asserted as soon as 5 ns after the rising edge of
02 during BS 2 . Therefore, under worst case conditions, the
extended addresses are on the bus for 155 ns. Masters can
generate PWR later as shown. This would allow the exten¬
ded addresses to be on the bus longer. However, slaves
should be designed to correctly respond in the worst case
situation.
10. To avoid conflict on the DO lines during a 16 bit read, as
in the situation described in note 9 above, the extended
addresses must be removed from the DO lines before the
rising edge of PDBIN.
Direct Memory Access (DMA) Requirements
A DMA cycle is a special case of a Bus Master taking over
the Bus to execute a memory read or write cycle. A DMA
device is required to generate all type M (Bus Master) signals
on the Bus.
Th e Bus Ex change
PHOLD is the signal used by one Bus Master t o reques t that
another Bus Master give up control of the Bus. PHOLD must
not be asserted true unless PHLDA is false and PRIORITY (if
implemented) is true.
One Bus Master (CPU) relinquishes control of the Bus to
another (DMA) as shown in the Bus Exchange Timing diagram.
The DMA device mu st control t he CPU’s bu s dri vers throu gh
the use of ADD DSB, DO DSB, STAT DSB and C/C DSB. It
must also control its own bus drivers through the use of sig¬
nals similar to those shown in note 6.
The CPU (current master) and the DMA device (new
Master) must both drive the Command and Control signals for
at least 200 ns at two different periods as shown in the Bus
Exchange timing diagram. During these two times, the
Command and Control signals for at least 200 ns at two differ¬
ent periods as shown in the Bus Exchange timing diagram.
During these two times, the Command and Control signals
are required to have the following levels:
1. PSYNC = 0
2. PWAIT = 0
3. PHLDA = 1
4 PDBIN = 0
5. PWR = 1
The DMA cycle timing sequence which follows is a sugges¬
ted implementation that meets all the requirements of the
generalized Bus Exchange timing. The sequ ence is c ontrolled
by the edges of 0 2 . At some previous time, PHOLD was asser¬
ted according to the limitations described in the first para¬
graph of this section. PHLDA is asserted true by the CPU
during BS 3 of the last CPU bus cycle. The bus exchange begins
on the falling edge of 0 2 while PHLDA is true (labeled 1 on
the timing diagram). The DMA bus cycle then pro ceeds as
described in the following section. At edge 8 of 0 2 , PHOLD
is driven false by the DMA device and henceforth die CPU is
again in control of the bus.
Proposed DMA Cycle Sequence
02 edge:
1. CPU Address and Data bus drivers turned off. DMA
Command and Control drivers turned on. The CPU and
DMA Command and Control signals must match values
described in the previous section.
2. CPU Status and Command and Control drivers turned
off. DMA Address, Data output and Status drivers
turned on. PSYNC = 1.
3. No change.
4. PSYNC = 0. PDBIN = 1 if memory read, or PWR = 0 if
memory write.
5. No change.
6 . PDBIN = 0 and PWR = 1.
7. CPU Command and control drivers turned on. DMA
Address and Data output drivers turned off.
8. CPU Address, Data output, and Status drivers turned on.
DMA Status and Command and Control drivers turned
off. PHCFLD = 1.
Acknowledgement
We would like to thank the other members of the Micro¬
processor Standards Committee for their support and invalu¬
able comments. Special thanks to Robert Stewart who is chair¬
man of the Committee. His leadership and organizational
skills have been a great aid to all of us.
We would also like to extend our thanks to Kells Elmquist
and Steve Edleman of Ithaca Audio. Both of these gentlemen
flew out to the Second Computer Faire to discuss their ideas
about S-100 bus extensions with us. Several of their ideas
were truly inspirational. Their intellectual prodding was the
force which created the extended addressing and the bi-direc¬
tional data bus proposals. Kells Elmquist is responsible for
another proposal which we will term “logical daisy chaining”.
This will be incorporated into the standard soon and will
make possible a significant advance in interrupt structures
within the present S-100 bus.
Number 25
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
235
u'' r»» oocaO'— cmca-tla so r-» co o> o — cm ca -y la vo r*» co <t\ o
CM CM CM CM CM CA CA CA CA CA CA CA CA CA CA -T -X -T -X -X -X -X -X -3" LA
Page 42
236
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
PRELIMINARY SUBJECT TO REVISION
*-'cn > —
- 6 .
U H « wo
O i/i *->
TD CLCO -O a
U OQ U CJ O
C 3
o—o ai cr m
x >* x x o x
*- x- *-> t- i- *-«
-T •— — •
i
C —
o o c o
■d >>m l
— u a
S-
m u- ki
c w — o
(71 O O 3
— i*_ H_ C-
l/l O
c >• u
w O —
3 — O *-*
*-* 4~> W Q.
<0 U <0 3
* O
l- >
O <D
i/) l/l
C
O fD
I — o
* X *-■
) 3 si
6 o
l/l l/l —
■ — — — t— O I
I C( - «
0O — —
<
l—
<
Ju
2 l
**- 3 i/l l- —
3 O — C
O ~ O *0
> X
E 2-
c c *-
dj l/l •-<
*-* «- c »0
COX W
— > — Cl
— 3
- X o
o «-> —
o z
— > H-
41 O X
C — l/l
C7> i/i
— (71
l/l o c
cm —
ci hi a *->
c it *-*
ji tro¬
ll —
i/i x
— ai
6
cc —
:* —
l/l
3 l/l l/l
e —
<u >* o o
x — *-* c
U ■o - ifl o
— C I- >* Q.
X O (0 l/l
2 E *->
m — oi c
— o I- c o
ro o Q. — l-
c — a n-
Oi > I Cl
— O l <DO
i/l "O 1-
i/l w «TJ
i/i O O i/i 5
3 > > X)
X a ro O I-
— — O <0
< i/t i/l X X
o — o
— X c
(71 •<-<
*->3 0 —
X O *-» 3
fo-
cc
►—
X
Number 25
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 43
237
TSA APPLICATIONS AND
DEVELOPMENT TOOLS
News Release Received: 78 March 10
Now available, a full complement of Z80/8080/8085 soft¬
ware devlopment tools. These are disk based, and oriented
towards the popular CP/M Operating System (TM Digital
Research). System development tools include a relocatable
linking macro assembler with linking loader, cross-reference
generator, and full library of modules. With the assembler is
included a symbolic debugger allowing user defined symbols.
Higher level language support is provided by interface with
Micro-Soft FORTRAN.
For advanced systems, TSA/OS is an upward compatable
CP/M-like operating system providing CRT screen control,
automatic library search, an extended batch mode with
turn-key system capability, as well as an advanced configura¬
tion scheme.
TSA Software has available a set of applications packages.
The TSA Database System uses a mixture of assembly code
and Fortran. The system uses table driven screen and record
formats; and has a mini-compiler to optimize record search
capability. The TSA Word Processor uses a normal terminal to
provide natural text editing with advanced formatting features,
including proportional printing. Full use of disk file's is provid¬
ed, as well as file merging for mailing list and similar uses.
The product line is S-100 oriented, but is flexible for all
other main frames, as all special functions are handled through
the operating system. Package prices: $100 and up, dealer and
OEM inquiries invited. TSA Software, 5 North Salem Rd.,
Ridgefield, CT 06877; (203) 438-3954.
THE SOFTWARE EXCHANGE
New Publication Received: 78 April 4
The Software Exchange is a new publication devoted to the
exchange of ready to use software for business and the home.
The Software Exchange provides classified listings for comput¬
er software. You will be able to match your application and
computer to those listed. Each program will have a description
of its operation, hardware requirements, and where the pro¬
vided materials can be obtained. If you have a special program
you need, you can place a Software Search in The Software
Exchange. It is very likely that someone has the software you
are looking for.
In addition, all advertising will be devoted exclusively to
software services available to micro and minicomputer users.
The Software Exchange is a bi-monthly publication available
soon at computer stores for $1.50 per issue, and by subscrip¬
tion for $8 per year (six issues). Box 55056, Valencia, CA
91355.
CORRECTION
Gentlemen: Received: 78 March 28
With regard to your reproduction of the Stanford
University News Release, I wish to correct one of your
references. The “memorandum” from CMU about the robot
was written by Mark Fox (not Mark Gos) and Brian Reid.
Sincerely, Graduate Student
Mark Sherman CMU Dept, of Computer Science
Page 46
240
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 25
Dr. DoBB'S JoURNALof
COMPUTER
(Calisthenics f) Orthodontia
Running Light Without Overbyte
Number 26 June/July 1978
Volume 3, Issue 6
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
SOFTWARE
Intelligent Terminal Implementation on the S-100 Bus Tim Pugh
Disk file transfer under CP/M using the IDS 88-Modem Board
4
Autodump Richard Emerson
A memory dumper for Poly-88 tape system
18
High Speed Cassette I/O for the KIM -1 Theodore E. Bridge
24
LAZARUS Andrew Hertzfeld
A program to resurrect BASIC programs on the Apple-II
31
A Tiny BASIC Extensions Package Leor Zolman
34
HARDWARE
TheZilogZ-8 U.R. Source
A PEEK at the new single-chip microcomputer from Zilog
28
© David Dameron 1979
MORE ON UNIX
AND MORE. . .
Dear Dr. Dobb, Received: 78 May 22
In the April 1978 issue of DDJ, page 3, Pierre duPont wrote
that he is planning to write an operating system similar to
UNIX for his 8080. Enclosed is a copy of a letter I sent to Mr.
duPont.
Jim Howell 555 Candlestick Way
San Jose, CA 95127
Pierre duPont
Salisbury School
Salisbury, CT 06068
Dear Pierre,
Your letter in DDJ attracted my interest. I have used UNIX
for about 2 months and I really like it. Before you start
writing your “UNIX”, you may want to read “The UNIX
Time-Sharing System” in the July 1974 issue of Communica¬
tions of the ACM (vol 17, #7), pages 365-375. This article,
which is part of the documentation for users of UNIX, gives a
description of the structure of UNIX and describes some of
the capabilities of the “shell” program. I can send you a copy
of this article if you need it.
As for some of your questions: (1) 8080 interrupts. To get
more than 8 interrupts for the 8080, the hardware must
arrange to supply a CALL instruction, rather than a restart,
for at least some devices when acknowledging an interrupt.
Intel has a chip in the 8080 family (I don’t know the number)
which can do most of this for you. Each I/O device can gener¬
ate a call to a different location, thus allowing as many inter¬
rupts as you want. The Intel chip handles 8 devices, I think.
(2) One way to store relocatable programs is to have, as
part of the program, one or more (or maybe none?) records in
the file, which are a list of the locations within the program
which need relocating. These records must be distinguishable,
of course, from program records. One problem with using an
unused opcode is that any code may appear as an operand of
an immediate instruction or in an area containing constants
or tables.
(4) 8080 vs Z-80. Advantage of using the Z-80: the
mrogram(s) comprising your “UNIX” may be smaller than with
tfi. 8080. Advantages of using the 8080: the program would
be distributable to more people, (assuming you plan to
distribute it): and the 8080 is what you have now. The disk
would appear to be the limiting factor in the speed of the sys¬
tem, so that the faster speed of the Z-80 relative to the 8080
is probably not an important consideration. The lack of
unused opcodes for the Z-80 is not a problem if you use a
relocation scheme such as in (2). These are the major consider¬
ations as I see them. I hope this helps you make your decision.
(6) I am interested in your “UND(” (or whatever you end
up calling it), but mainly from the standpoint of keeping up
with developments in the computer hobbyist area. My system
is the COSMAC ELF II (using the RCA 1802) and my choice
for a bigger system would be one using the 6800, such as
SWTPC or MSI.
Good luck and keep us informed (thru DDJ).
Sincerely,
Jim Howell
Dear Sirs: Received: 78 May 19
The purpose of this letter is to introduce UNIX for the
8080 microprocessor. The system is called CHAOS, an acro¬
nym for Clairemont //igh A LTAIR Operating System.
CHAOS is currently in operation at Clairemont High, and
offers the user the following capabilities:
* A maximum of nine timeshared processes. A process
may be an interactive user, lineprinter controller, and
executing command, minicomputer translator, etc.
* A choice of three computer programming languages:
BASIC —MITS Disk Extended Version 4.1 (modified
for CHAOS).
8080 Assembly —relocation table allows patching of
relative addresses, and placement of
the program anywhere in memory.
Shell — operating system command lines that are
contained in a file and may reference para¬
meters in the calling command line via a
macro structure.
PASCAL—hopefully will soon become the fourth
language supported by CHAOS.
* User-maintained system. All updating and expanding is
easily accomplished due to the power of CHAOS.
* A complete accounting system that allows program/
file sharing, access rights control and unlimited sub¬
accounts. CHAOS supports six file types: 8080 Machine
Language, BASIC program, sequential data, Shell com¬
mand line, random data and directory. Access rights
include read, write, ownership and execute.
* Interfacing with the Hewlett-Packard 2000 Access Sys¬
tem BASIC minicomputer and a text editor, assembler
and loader on that system.
* Storage of programs and data on a maximum of eight
floppy disk drives and one cassette tape drive.
* Mechanisms within the Kernel (timeshare controller)
to handle semaphore requests and job queuing.
* Program nesting, recursion and inter-language calls via
the CHAOS file module and stack schemes.
Our current hardware configuration includes:
IMSAI 8080 microprocessor
64 K RAM
Memory Switching Device for CHAOS
2KPROM
6 serial input/output ports
Three parallel plus one serial input/output port
Disk Controller
Cassette Interface
4 Video Terminals
1 Printer/Terminal
Diablo Lineprinter
2 MITS Floppy Disk Drives
Cassette Player/Recorder
I would welcome any inquiries regarding CHAOS, and
would be interested in learning about other like operating
systems for the 8080 microprocessor.
Sincerely, 3632 Governor Drive
Mary Elizabeth Kroening San Diego, CA 92122
Aha, do I sense the beginnings of a dialogue? -TRW
Number 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 3
243
Intelligent Terminal Implementation
for the S-100 Bus
DISK FILE TRANSFER UNDER CP/M USING THE IDS 88-MODEM BOARD
BY TIM PUGH
9655-M Homestead Court
Laurel, MD 20810
(301) 776-5253
There is now available a board for the S-100 BUS which,
when coupled with appropriate software, can add a powerful
new dimension to your system. The board I refer to is an
Originate/Answer Modem board and is being produced by at
least two manufacturers: D C Hayes Assoc, of Atlanta, GA and
International Data Systems (IDS) of Falls Church, VA. With
an Originate/Answer Modem you can implement the following
functions:
1. Intelligent Terminal
2. Remote Console
3. PCNET Node
There are undoubtedly other functions which can be imple¬
mented but these three are fairly clearly defined.
The first of these functions (Intelligent Terminal) is imple¬
mented to a significant extent by the program which accom¬
panies this article. The basic purpose of this function is to
allow you to communicate with a large “Time Sharing Com¬
puter” (TSC) and effectively use the various components of
your “Personal Computer” (PC) in carrying on this communi¬
cation. For example, you may wish to use your video terminal
for some of the communications and then switch to a printing
terminal or hard copy device at the appropriate time. Also,
you may wish to transfer data between the PC’s floppy disk
and the TSC.
This last activity is truly significant if you are taking pro¬
gramming courses or are a professional programmer whose
company computer allows Demand Mode access; i.e., access via
a terminal. It has been my experience that access to TSC sys¬
tems in either a school or professional environment is seldom
available during “prime time”; i.e., the hours of 8:00 AM to
5:00 PM. Thus, one must either enter his programs via cards—
not a very exciting prospect—or do most of his work during
“odd hours” when the available terminal lines are not heavily
utilized. However, given the ability to transfer files between
the TSC and the PC one can prepare his source input at his
convenience using the text editor of his PC system. The source
statements are stored on a floppy disk and later transferred to
the TSC. Thus, the TSC is needed only for compilation and
execution. Subsequent corrections to the source “deck” can
be performed on the PC system. I find that most of the time
I spend on a computer is used in editing source statements
and comparatively little in compilation and execution. This
means that only a small portion of one’s work need be
performed at “odd hours” and this can be performed in the
comfort of one’s home.
The second function (Remote Console) is my next project
and should not be nearly so difficult as the first. With such a
capability a businessman who has a computer system at his
place of business need only purchase an additional terminal
and acoustic coupler to bring the capabilities of that system
into his home. Or the professional; e.g., engineer or program¬
mer, can have access to his home system from his place of
work. Or the person who wants to demonstrate the capabilities
of a computer system to a potential customer can do so with¬
out having to carry the entire system with him.
The third function (PCNET Node) will allow both mes¬
sages and program files to be transferred between two or more
PC’s or between a PC and a data facility whose communication
protocol is compatible with that of the PCNET. This capability
opens up all sorts of possibilities. The correspondence I have
received to date indicates that the protocols for this network
will be ready for general distribution in the first half of this
year, with prototype PCNET software available in the second
half of this year. On March 5th of this year a demonstration of
existing PCNET software was given when an 8080 system in
Sunnyvale, CA sent messages to a PET in San Jose, CA. Noise
was injected on the phone lines and the two systems success¬
fully detected bad “packets” and retransmitted good ones.
Additional information concerning this can be had by contac¬
ting:
PCNET Committee
701 Welch Road, Suite 226
Palo Alto, CA 94304
(415) 328-2411
It is quite probable that given these functions and the
ever increasing power of PC systems and software, many
professionals will be able to perform a good deal of their
work in the convenience of their home augmented by confer¬
ences between coworkers at their place of employment.
Modem Selection
In choosing a modem I was very concerned that it have a
stable frequency source and good filtering characteristics.
About 18 months ago I built the Pennywhistle modem (acous¬
tic coupler) kit. It used a 555 timer IC with a two stage filter
and phase locked loop. While this modem would work (after
a rather tedious allignment) with one TSC, it was not reliable
when interfacing with a second and would not function at all
with a third. All three of these TSC’s were within a radius of
20 miles of my terminal. I understand that certain design
improvements have been made in the Pennywhistle since then.
With regard to choosing between an acoustic coupler and
one of the S-100 BUS Originate/Answer Modem cards, the
function of “Intelligent Terminal” can be performed by either.
Page 4
244
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
I have used an Anderson Jacobson AD 342A Originate/Answer
Acoustic Coupler with great success in this application.
However, acoustic couplers can neither provide auto answer
nor automatic dialing; this precludes the Remote Console
function and places considerable limitations on the PCNET
function.
Having decided on an S-100 BUS card implementation over
the acoustic coupler approach I then made a comparison
between the IDS and D C Hayes boards. The following differ¬
ences seemed significant to me:
1. Hayes — Uses the Motorola MC14412 Modem chip.
IDS — Uses the Motorola MC6860L Modem chip.
2. Hayes - Has a 6-pole filter in the receive channel and
no filtering in the transmit channel.
IDS — Has an 8-pole filter in the receive channel and
a second 8 -pole filter in the transmit channel.
3. Hayes — Has two software selectable BAUD rates, 110
and 300.
IDS — Has a BAUD rate which is variable under pro¬
gram control from 66 to 600 BAUD.
4. Hayes - Does not provide dial-tone detection.
IDS — Detects dial tone and sets a corresponding
status bit.
5. Hayes — Requires host processor to perform dial
pulsing.
IDS — Provides auto-dialing in hardware.
6. Hayes — Requires CBT be supplied with internal power
source.
IDS — Supplies current source for CBT thus allowing
the less expensive model CBT to be used.
7. Hayes - Has no published receiver sensitivity.
IDS — Provides communication down to —58 dBm.
8. Hayes — Claims to provide for direct connection to
telephone lines.
IDS — Requires a coupler (CBT or CBS).
9. Hayes — Assembled & tested $279.95
Kit (not available) -
IDS - Assembled & tested $395.00
Kit $245.00
The difference between the two modem chips is consider¬
able. In essence, the MCI4412 does not perform the “super¬
visory” functions that are provided by the MC6860. For
example, the 6860 in answer mode detects the ring, causes the
phone to go off hook (i.e. answers the phone) places the
carrier on the line and detects the remote tone (if present). All
this must be done under software control on the 14412. There
are many other individual points of difference. The interested
individual should get spec sheets on each to make a proper
comparison.
A Motorola application note entitled “Low-speed Modem
System Design Using the MC6860” states on page 13 that “A
complete full duplex system will most likely require operation
with input signals down to —50 dBm at the line input. This
requires a receive filter network having at least 8 poles... and
a local transmit filter having 4 poles to provide 25 dB local
transmit signal harmonic rejection.” Notice that the IDS unit
has 8 poles in both transmit and receive. The fact that there is
no transmit filter in the Hayes unit probably precludes success¬
ful full-duplex operation. While full duplex is not required for
the Intelligent Terminal function, I do believe it is necessary
for the Remote Console function. The console (LS Dumb
Terminal) I am using to generate this article is operating in full
duplex. Were it not, I would have difficulty using my TDL
Z-TEL text editor. When I enter an ESC character to
terminate a string, it echoes a $. When I enter other control
characters; e.g., control Y, it echoes Y. In half duplex this
would not occur.
The —50 dBm receive level spec mentioned by Motorola
agrees with the specs for both the Anderson Jacobson AD
342A Acoustic Coupler mentioned earlier and the BELL 103/
113 Modem. On page 3 of a report by VADIC entitled
“Telecommunications From The Terminal User’s Viewpoint”
the statement is made that “to enable 98% of all calls to be
received, a modem would have to be capable of demodulating
signals as weak as —50 dBm.” Note however, that the IDS unit
exceeds this by 8 dBm — a further indication of superior
design.
The reason for having two 8-pole filters in the IDS unit
rather than 8 for TX and 4 for RX is that the filters are not
actually identified with TX and RX but with high band and
low band. The originator of the call always transmits on the
low band—1270 Hz Mark and 1070 Hz space—while the
device which answers transmits on the high band—2225 Hz
Mark and 2025 Hz space. Thus, each filter is designed for
optimum performance for its particular band. In the Hayes
unit there is but one filter and it is always in the receive chan¬
nel. Thus, it must function as a high band filter for originate
mode and a low band filter on answerback by component
switching. This results in less than optimum performance (even
for 6-poles) on either band. To get some quantitative feel for
the difference in the two filter designs, the IDS unit employs
a total of 32 Op Amps in its filter and detector circuit as com¬
pared with 8 Op Amps in the Hayes unit. As you can see,
— 58 dBm is not easily achieved.
The two apparent advantages the Hayes unit has over the
IDS unit is ability to connect directly into the phone line and
price. Needless to say, price is an important consideration. It
must be weighed against the probability of success each unit
is likely to have in error free communications. This is especial¬
ly true in long distance communication-meaning any distance
requiring more than one telephone switching station to be
involved in the connection. Also, considerable variation in
local communications can result from differences in line loss
and line noise. This variation probably accounts for the mixed
results I described earlier for the Pennywhistle when trying to
communicate with three different TSCs. In the final analysis,
specifications are only indicators and it is the actual perform¬
ance of a unit that counts. Unfortunately I have not had the
opportunity to make any “A B comparisons” between the two
units. I can only say that I have been using the IDS unit suc¬
cessfully for the past three months in communicating with the
same three TSCs mentioned earlier. I have operated with these
TSCs at 110, 150 and 300 BAUD. On April 24 I communi¬
cated for the first time with another IDS 88-Modem. The
transmission was error free at 300 and 450 BAUD. It was
readable but not reliable at 500 BAUD; i.e., about 85% error
free. This test was run between Laurel, MD and a location near
Dulles Airport in Virginia; a distance of about 35 air miles and
undoubtedly involved two switching stations. The direct con¬
nection feature of the Hayes unit is discussed in the section on
Telco Interface which follows.
If you choose to get the IDS kit as I did, be advised that
this is a rather difficult kit to build and should not be under¬
taken by someone who has not built several others in advance
Number 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
245
of it. This does not imply a poor quality board. It is due to the
high component density required to put everything on one
board. The major difficulty is due to close component place¬
ment-raising the possibility of solder bridges—and the fact
that most passive components, i.e., resistors, diodes, etc., are
mounted vertically. In addition, there are several signal level
adjustments which must be made: TX Carrier Level, Dial
Tone Detector Gain, Low & High Band Filter Gain, and
Threshold Detector Sensitivity. But do not despair, IDS will
accept your completed kit and both make the necessary
adjustments and check the board out for proper operation.
Theoretically, this service is free provided no repairs are neces¬
sary. In my case, I was charged just over $30.00 for certain
discrepancies. This is still cheaper than the assembled Hayes
unit ($275 vs $280). I strongly advise letting IDS do the
gain adjustments. When connected up to a data coupler—
the gadget that interconnects y6ur modem board to the tele¬
phone lines—if your signal level is too high, it is attenuated to
the proper level by the coupler. So what, you say. The prob¬
lem is that the received signal will be attenuated by an equal
amount.
For further information on the IDS 88-Modem contact:
International Data Systems, Inc
400 North Washington St.
Suite 200
Falls Church, VA 22046
(703)536-7373
Telco Interface & Protocol
Once you have the IDS 88-Modem board up and running,
it is necessary to interface it to the telephone system. The
conventional way to do this is to install a data coupler be¬
tween the modem board and the telephone line. The data
coupler—also known as a Data Access Arrangement (DAA)—
comes in two forms: CBT and CBS. The CBT uses DC current
loop control while the CBS uses RS232 voltage levels for the
same purpose. The CBT is less expensive than the CBS but re¬
quires an external power source. This source is supplied by the
88-Modem board. Also, the CBT can be purchased for
$125.00 from IDS. Whether you buy the device or rent it from
Telco ($4.00 to $5.50 per month) the CBT is usually recom¬
mended unless a CBS device is already in place.
The reason the data coupler is necessary is that it provides
for ring detection (necessary for auto-answer) and off hook
control (the equivalent of picking up the handset) in addition
to DC isolation, impedance matching and surge protection. As
of June 1, 1977, non-Bell modems may be directly connected
to the phone line without a requirement for a Telco-
provided DAA. However, in order to do this and still provide
for auto answer capability the system must, at a minimum, pro¬
vide for ring detection (the IDS unit provides this while Hayes
does not). Additionally, proper impedance matching and
signal level requirements must be met. If this is done then the
manufacturer must get his device approved and certified. Any
manufacturer who has done so is given an FCC authorization
code and REN number. Since D C Hayes does not give this in¬
formation and since both the telephone company and FCC
regulations prohibit direct connection of an unapproved de¬
vice, I would be very cautious about this. Note also that the
DAA not only protects the switched network from the
modem, it also provides protection to the user from electrical
surges that routinely occur on the telephone lines due to
lightning. Direct connection does not offer this protection and
resulting risk is high that the modem board and/or the compu¬
ter of which it is a part will be damaged.
I can’t give you much help when it comes to CBT installa¬
tion as I rent mine and it was installed by Telco. As I had no
one to advise me in this regard, I decided to play it safe.
Telco will want to know what options you want installed with
your CBT. The suggested options are given in the manual
which accompanies the IDS modem. Associated with the op¬
tions list are some symbols which have meaning only to
Telco but using these symbols for brevity I would say that
options “F-12” and “7.3” are of questionable value and that
“G-14” should actually read l ‘G-13”. If you are timid, as I
was, and want Telco to install the coupler, I believe they will
do the installation even if you purchase the CBT from IDS.
In the Automatic Answer mode the combination of soft¬
ware and modem hardware must supply the logic necessary to
answer a call. In support of this the following sequence of
events take place:
1. Idle The system has been initialized and awaits
call.
2. Rl-on The telephone rings.
3. OH-on The modem commands the CBT to go “off
hook”.
4. DA-on The modem places the CBT in the data
mode.
5. Delay 1 to 3 second delay before CCT. This allows
the automatic billing equipment to register
the call.
6. CCT-on Indication that the connection has been
established.
Normal data communications is performed.
Terminate the call and break the connection.
Leave data mode.
7.
8 .
9.
10 .
OH-off
DA-off
CCT-off
To originate a call automatically the CBT must be com¬
manded to go “off hook”, detect dial tone and generate the
dial pulses corresponding to the phone number being dialed.
When the dial tone is detected, the DA lead must be turned off
and after CCT goes off, the OH lead is pulsed to produce the
dialing function. Thus, the following sequence of events occur
when in Originate Mode:
1. Idle The system has been initialized in prepara¬
tion for this mode.
OH-on Go “off hook”.
DA-on Enter data mode.
CCT-on Indicates connection has been established.
**** Wait until dial tone has been detected by
modem.
Data mode must be off to enable dialing.
2 .
3.
4.
5.
6 .
7.
8.
9.
DA-off
CCT-off
OH-pulsed (perform dialing operation).
DA-on Prepare for normal data transfer (DAta
mode).
10. CCT-on Indicates connection for normal data trans¬
fer has been established.
11. **** Normal data interchange.
12. OH-off Terminate communications.
13. DA-off Discontinue data mode.
14. CCT-off (the phone has been hung up and idle state
restored).
Page 6
246
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
88-Modem Block Diagram
The normal dial pulse rate is lOpps but the pulse rate is var¬
iable under software control. I have been successfully employ¬
ing a dial pulse rate of 20pps. This is almost as fast as “touch
tone” dialing and at this rate the average 7 digit number can
be dialed in under three seconds.
88-Modem Board Function & Interface
The 88-Modem board can be broken down into 5 major
functions as depicted in the block diagram of the device. The
UART function is provided by a General Instruments AY-3-
1014/1015 UART chip. The MODEM function is provided by
the Motorola MC6860L chip. The DIALER function consists
primarily of four 74192 DECADE UP/DOWN COUNTERS.
The remainder of the functions employ a variety of devices.
The 88-Modem requires 4 consecutive I/O port addresses.
Following the suggestion of the manufacturer, I have assigned
them the values of 0C0H thru 0C3H. They may be changed by
using the DIP switch provided on the board. Due primarily to
the sophistication of the MC6860L most of the TELCO inter¬
face activity described earlier is handled automatically by the
hardware.
The following sequence illustrates the principal steps re¬
quired to initiate, perform, and terminate the Answer Mode:
1. Send a mode command to the UART establishing the
number of data bits, stop bits (1 or 2), and parity (even
or odd).
2. Load the BAUD rate value (8 bits) into the Rate Gen¬
erator.
3. Send a mode command to the MODEM; i.e., DTR,
<300 BAUD, BRK-REL, ESD, ELS (mnemonics ex¬
plained below).
4. Send a second mode command to MODEM as in 3.
which removes BRK-REL.
5. Read 88-Modem status and test for Clear to Send
(CTS); i.e., the phone rang & the remote carrier was
detected.
6. Commence normal communications.
7. Test status for loss of CTS and test data for control-D.
8. If 7. then terminate by resetting DTR in MODEM con¬
trol byte.
Steps 1. thru 4. above can be considered initialization. Once
this is done, the hardware takes over. Referring to the block
diagram, the Answer sequence is initiated by the presence of
RI (Ring Indicator) at the MODEM input. The MODEM acti¬
vates the “Ans Ph” (Answer the Phone) which sends OH (Off
Hook command) to the CBT. Since we are not in Dial Mode
(DMD), the presence of “Ans Ph” also generates DA (DAta
mode). The MODEM then places a 2225Hz tone on the TX
line. It then awaits a 1270Hz tone from the RX line combined
with THD (ThresHold Detect). If this condition continues for
the prescribed time, CTS (Clear To Send) is set in the status
byte which carries us through step 5. above.
In step 6., data is transmitted to the remote device by
loading a data byte into the UART. The byte is shifted serially
into the MODEM over the TX line at the prescribed BAUD
rate. The MODEM then employs “Frequency Shift Keying”
(FSK) to impress the serial data stream onto the carrier; i.e.,
a binary 1 is transmitted as a 2225Hz tone for the duration of
a bit time while a binary 0 appears as a 2025Hz tone for one
bit time.
The resetting of DTR (Data Terminal Ready) in step 8.
causes “Ans Ph” to go to zero and results in the loss of OH
(Off Hook command) thus, “hanging up the phone”. A test
for control-D is performed in step 7 since this character typed
either remotely or at the local console signifies that communi¬
cations are to be terminated.
In step 3. certain mnemonics were used which will now be
defined. “<300 BAUD” instructs the MODEM that the baud
rate will not exceed 300. “BRK-REL” resets the BREAK de¬
tect flip-flop. This is a pulsed signal and must therefore be
removed in step 4. “ESD” (Enable Space Disconnect) condi¬
tions the MODEM to “hang up” if it detects a constant space
tone in excess of a predefined period. “ELS” (Enable Long
Space) is the opposite of “ESS” (Enable Short Space) and
establishes the space duration at which disconnect occurs.
SS=0.3 seconds and LS=1.5 seconds.
The Originate Mode is implemented using the following
sequence:
1. Load the DIAL rate (20pps) into the Rate Generator.
2. Set the MODEM to Originate mode; i.e., DTR, OH,
BRK-REL.
3. Test status for Dial Tone Detect (DTD).
4. If DTD then load first BCD digit to be dialed into
DIALER.
5. Test status for Dialer BusY (DBY).
6. If not DBY then load next digit, etc.
7. Load the UART mode—number data bits, etc.
9. Load BAUD rate into Rate Generator.
10. Test status for CTS; i.e., carrier detect.
11. Change MODEM mode from Originate to normal; i.e.,
remove OH and allow space disconnect.
12. Commence normal communications.
13. Test status for loss of CTS and test data for control-D.
14. If 13. then terminate by resetting DTR.
In step 11. the OH bit in the Modem control word was reset.
This does not mean that the connection is broken. Actually,
Number 26
Dr. Dobb's Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, CA 94025
Page 7
247
IDS refers to this bit as SH (switch hook). I call it OH because
when set it forces an off hook conditions. However, the hard¬
ware will maintain the OH line going to the CBT in the true
state provided either that this bit is set or if SH coming from
the CBT is true. In the Originate Mode the frequencies used
for transmission of data are channeled through the low band
fdter and are 1270 Hz for a mark (binary 1) and 1070 Hz for a
space (binary 0). The received data is channeled through the
high band filter with 2225 Hz for a mark and 2025 Hz for a
space. This is just the reverse of the Answer Mode.
Program Functions
As previously stated, the program supplied with this article
performs the Intelligent Console function. As such, it is
designed to establish communications with a large scale com¬
puter which allows terminal access. In support of this it pro¬
vides for both “manual” and “automatic” dialing of the
remote facility and accomodates operator selection of one of
6 baud rates. Manual dialing means entering the phone number
via the console keyboard while automatic dialing means that
certain alpha characters correspond to special phone numbers.
When a predefined alpha character is entered in place of the
first digit of a phone number, it is replaced by the associated
phone number sequence.
Once communication with the TSC has been established the
system enters the CHARACTER TX/RX mode. As the name
implies, it provides for single character—versus line or block-
transfers between the PC and TSC. From this mode one can
enter either the FILE TX or the FILE RX modes. These
modes provide for the transfer of disk files between the PC
and TSC.
The Intelligent Console function requires only Originate
Mode operation. In order to check out the Answer Mode and
supply a limited version of the Remote Console function the
program can be placed in the answer mode. Again the BAUD
rate can be selected from the 6 predefined values. When the
phone rings, the system answers by placing a 2225 Hz tone on
the line and awaits receipt of a 1270 Hz tone in reply. If not
received within a specified period, it hangs up. If the tone is
detected it sends a sign-on message and enters the CHARAC¬
TER TX/RX mode. This allows for communications between
the console operator and someone at a conventional terminal;
e.g., a teletype unit. It also provides for file transfers to be
initiated either remotely or at the system console.
Since it is possible to initiate file transfers remotely, one
can load the appropriate floppy disk, set up the system for
Answer mode and retrieve the file at a remote system with the
PC unattended. The details of system operation are given at
the beginning of the program listing.
System Requirements
The program is designed to run under CP/M and except for
the I/O peculiar to the 88-Modem board, uses CP/M supplied
functions to perform conventional I/O. In order to operate at
a given BAUD rate it is necessary that the console device be
capable of a least twice that BAUD rate. Thus, if a 30cps print¬
ing terminal is used it is necessary to operate at 150 BAUD
or less. Unfortunately, this also applies to an on-line printer
even if the console is a high speed video display.
A second limitation occurs in file transfers. The data is read
or written to the disk in 128 character blocks. This means that
by the time the next record is transferred to the disk, the head
has unloaded—mine unloads after 8 revolutions without
access. Since it takes about 30ms to load the head and
additional time for sector seek, two or three characters can be
lost per record when operating at 300 BAUD. At 110 BAUD
this problem does not exist. One solution to this problem is to
use double buffering coupled with interrupt processing. I have
purchased and assembled an IMSAI PIC-8 board for this pur¬
pose but have not yet had time to write the necessary
software. Another approach is to have the TSC cooperate by
interrupting data transfer on command from the PC and then
continuing when commanded. Unfortunately, many TSCs are
not easily made to cooperate in this manner. Of couse, if you
are communicating with another PC there is no problem in
establishing the necessary protocols to accomplish this.
While on the subject of floppy disk drives, I do not know
how well the file transfer will perform at 300 BAUD even
given double buffering with interrupt processing if the disk
controller does not have a DMA interface. With DMA, the
controller is given the buffer address and number of bytes
to transfer and it uses cycle steal to effect the memory to
disk transfer. The CPU is allowed to handle other processing
chores as necessary. Without DMA, the CPU must control
the transfer of every data byte between the memory and
disk controller. This may load the CPU to the point that it
can’t handle both disk and modem transfers without losing
data at the higher BAUD rates. I have a Digital Systems floppy
disk system with DMA controller and have been very pleased
with its performance. I have successfully run it under CP/M at
4MHz in an IMSAI chassis using a Cromemco Z-80 processor
and Industrial Microsystems Memory boards. The disk control¬
ler is available with “dual density”. This means it is both hard¬
ware and software switchable between single and double den¬
sity. The system uses Shugart 800 drives. Further information
on this system may be had by contacting:
Digital Systems
6017 Margarido Drive
Oakland, CA 94618
(415) 428-0950
Another potential problem has to do with transmitting a
file to a TSC. Depending on the front end (communications)
processor, it may or may not be able to take data continuous¬
ly. All systems seem to take a single line, but since they are
timeshared they may not be able to get back in time to catch
the next line. To help correct this problem I have inserted a
“handshake” routine. This is designed to wait for acknowledg¬
ment of a given line before transmission of the next line. The
current implementation looks for an ETX character before
transmitting the next line. In order to determine the appro¬
priate handshake character for a particular TSC a subroutine
called SHOW can be used. The normal CHARACTER TX/RX
routine screens out all but a select group of control characters.
If it is desired to display any received control characters (other
than CR and LF) then the “SHOW” subroutine can be patched
in. At location 0B62, replace “CALL TCHAR” with “CALL
SHOW”. SHOW begins at location 08A8. Handshaking is only
employed in the FILE TX routine, and only there if specifical¬
ly requested by the operator during system initialization (see
operating instructions).
Pass 8 Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025 Number 26
248
Perhaps after citing all these potential problems I should be
specific about what I have been able to do with my system.
1. CHARACTER TX/RX MODE — I have communicated
in both originate and answer modes without error at
110, 150, 300 BAUD. I have communicated at 450
BAUD in answer mode without error.
2. FILE TX — I have transmitted files in both originate
and answer modes without error at 110 and 300
BAUD. The 300 BAUD rate was performed without
handshake to one TSC and with handshake to another
TSC.
3. FILE RX — I have received files in both originate and
answer modes without error at 110 BAUD. The trans¬
fer is also error free at 300 BAUD but characters (2 or
3) are dropped during the disk writing operation due to
head loading delay cited earlier.
4. REMOTE CONSOLE - I have set up a file and put the
system in answer mode and then left it unattended. I
then called the system, got the sign-on message and
initiated a file transmission both at 110 and 300
BAUD.
Thus, it takes a while to learn the “personality” of each dif¬
ferent TSC but the system definitely functions.
There is one routine in the program that is system depend¬
ent. It is the DELAY subroutine which begins at location
07DA. It outputs null characters to a 300 BAUD printer as a
measure of delay time. This can easily be replaces by an equi¬
valent timing loop. As I recall, it is only used to time the dura¬
tion of a transmitted BREAK. Thus, the program will probab¬
ly work in all other respects as is.
One area of the program you will want to change is the pre¬
defined phone numbers. These are found beginning at location
016E. A rotary dialer is supported for the first 4 phone num¬
bers as detailed in the operating instructions. The last two
numbers are good for checkout purposes. They are the TELCO
time and weather service numbers. Entering a “W” in place of
the first digit to be dialed generates the weather service num¬
ber while a “Z” gets you the time service.
For those of you who may be new to CP/M there is a users’
group headed up by Anthony Gold which is very active and
currently has 25 single density floppies full of software. This
software is available to all members ($4.00 annual member¬
ship fee) for only $8.00 per diskette. I intend to make the
source for this program available to the group in the near fu¬
ture. Additional information can be had by contacting:
CP/M Users’ Group
164 West 83rd Street
New York, NY 10024
I assume you will want to customize this program to suit
your own needs and I believe what has gone before will be of
help in doing so. If you are in the Baltimore-Washington area
and need some help in checking out transmission at BAUD
rates above 300 or would be interested in forming an informa¬
tion exchange group please give me a call.
3 as
X X> X
Ul O m s;
t- 'M n X
W (V 3
UJ • lO X
x x c—
'3 -C-
3 X _1
a. I ui«
in x «—
x n 3 o
Ht)<rn
HO\J«
■*< Q ul
f- 3 :
NUl L
-u jj
3 < as
Ul X
J K D
jaju
3 =
Ul CO
>-t vi
U. 3
V|
3 <
3 Hi
x
< 3
CO CO UJ 00 X f-i I
Z < 3
3 3"
U H
CO X CO
COKH
•X H* 3
UJ UJ
_J l_>
VI U1
U. OS
> X
MlOH
UZH
3 X o
< 3 3 u. as h i
uj o
U. X
00 a.
x uj
X X
t- f-
UJ 3
3 -1
X 3
3 3
X
uj cO
f-
X UJ
ZXld
< UJ
as a. -
ul cO X
a. < z «
3 ^ x
Ul ;
* 3 H a
3 Z —J ►
U. VI < J
■X U
X < b
f-i X • 3
H CO : li
< 3 X
S Z r -
X
X X -
UJ
t- UJ
CO H t
x X :
CO H v
H« c
UHL
X .2 t
CO OS
X 3 -*
UJ Hi 3
X X _J
X X
= CO
e co i
uj 3
3 8- Z •
= X X V.
-t os X X
C Hi
d 3 O z
-• 3 Z UJ
E X
d X a _d
z x ui
-• -o X • J S
a H« uj «
U. 3 vi co s
3 Hi UJ c
_l 3 X
j a. i-i ci
3 z x a
CUJU I *—«
d CO UJ rd Z Hi
-• H* X 3 3
C CO UJ H UJ
d H 3 lO IO x
c\j t-n
■i UJ f J CM < Q
3 Q Z <M
3 H -UJ
sixujilio
a x z x
-» X x Hi 3 co
- uj 3 M co
t u. X uj
S CO U1N r
d Z CO H« X
u X Hi < _l
o -I X o X
U. < Ul l— 3
u VI -« Z O 3
0 Uj i- —I
3 3
-J UJ UJ
o X x
CO X Hi
3 UJ c
E UJ X UJ .
ChHQ:
O 3 H HO.:
UJ 3 3 U
X Z UJ V
Hi X Hi 2
3 3 a.
X o V<
UJ X UJ
! 3 CO a.
CO Z X
. CO X X
-* X 3 X
CO -J Z X
Z 3 3 3
X z z a. uj
H H CO O
K Q QC Ul H
3 x as ;»
u. 3 Hi UJ
O CO UJ 3
= c_> X x
- ' VI Hi UJ
u. H.
U. o
a. X X X a. 3 H< :
X _l a. x
*H Z _J -CO X rd -
3 3 -I 3 < vi vi
X Ul 3 CO _J
CO - 3 X :
vt X “Z UJ X H
X as UJ x _j Hi
Z UJ UJ H < UJ VI
3 H* =» H* z Hi z ►
VI 3 UJ <
CO X 3 Z
co as 3 3
( JlOr>
• UJ X UJ
I > CO Ul
: vi as
« H* til 3
c X
> Z Hi UJ
3 o X
o Hi
X ro
X H« >< UJ 3 3
3ZUJU13.
-• X Hi X Ul
CO Hi Z X
a x x 3
dOrtZHUI
- 3 H< X
a uj ui 3 f—
JHI3UI
e < H« ul h« 3
3
co uj 3
uj ■* c
NCOzli
<_JUJUJXHi3*
X 3 3 -4 Hi X Hi
Hi OS VI o z UJ
H* > CO 3 -I OS
_J Z uj z Ul X
<33330=3-
X 3 3 H uj H* -
as uj ^ H C.
O 3 H« -1 O X
Z UJ 3 < X uj uj i
Z X 3 O. X Hi f
a. X U. < Z 3 < U. ►
= _l -I X U
-I _l < OS 3
vi Z H* L
: z uj x x H*
-* o O x UJ
ce as x ui 3
- uj a. a. vi x
- x as co
< H< uj uj as cO
JHIX4UJ
E Ul H* H« 3 X
— H* 3 CO X h
X Z H" ■
u ul 3
h X H co :
M Ul
a < co
• Ul 3 3
3 uj as _
3 X 3 C
H. a. o
- X co V
■4 X VI «
e 3 x ;
H 3 H *
3 _1 3 X
H I
_ UI Ul CO
uJ -I >-• x _i x as
X < u. • M Ul Hi Ul
H* •—i 3 cO CO Q CO Hi
~ ' * as 3
UJ <
3
O Ul 3
HU1H
a- 3
3 UJ
-J M ►
uj 3 x
Z CO Ul c
3 Z Hi
Hi 3 z c
3 ui :
3 H* a. XHffl
3 X c,
■Si UJ X -
Hi 3
Hi Uj 3 :
H« Z C
-uj VI :
3 3 _J
3 UJ 3
Ul UJ
-J X _l
Ul X
CO CO Z t
< 3 •
CO X H
uj uj x 3
X Hi x c-i
Hi X Hi
< 3 •
z z
HUH
3 X 3
- X =
3 < Ul uj
u 3 3
S X 3 z
Ul VI 3
x Ul
H* Hi f-
X 3 X
H*
3 X
3 Z X 3 >
U. Z < 3 Ul
•-« 3 3 Z < 3
3 s
h 3 lO ;
ui UJ
CO Hi CO :
1 X 3 UJ Ci
a uj uj x ti
S Hi _1 Hi C.
-I 3 UJ «
u < co 3 o
os H ci
J X Hi U
: x iiJ 3 i
- 3 CO UJ :
z
a as Ul 3 Li
< Ul x H 1
X Hi CO b
a H« co
c 3 a; < u
d 3 a
-« U. (O t
J • as
< - ul uj a
c •* 3 X C
t -3 X i-
2 rsl 3 3 a
: x 3 z o
» : coo:
J < X -
' O CO «-
3 a. - i—
a. X -
3 3 CO O
E CO -J •—
(jJ UJ -
E Hi X O
d 3 H* O
X
- as 3 U.
Q X UJ 3
X 3
-• Ul 3 Z
< x x x
h na x
i x uj
* H» _J
1 VI '4
> CO X -
1 M • = X 3
1 X '*1 X Z OS
H* 3 < a.
X X
X X
< ui
t UJ z
-l O
) X 3
- 3 3 UI
Z os X
S Ul 3
3 3 Z
u or <
uj as 3
: X uj 3
C X Ul Hi UJ <
> as as z X X
\ Ul Hi X
J x ui ui
<HXX -X
> H« X 3
■ OS ui Ul
j Ul X 3 as _j
: [-• H ul us o
3 vi h* uj X
J < ■* M u. z
: as vi x 3
' < X X Z 3
X Z X X
1 3 3 Z us
S = •—, < Hi •
S H« US =
Ul < f-i UJ u,
X 3 •
3 3 X
a. Hi ui
JO.UJX j
: uj uj os
< 3 X M 3
3 < VI Ul X
3 H 38 x Hi
Z H X X Ul
< 3 3 3 OS
3 os z X 3
X < X 3
: 3 3 x vi z
> UJ 3 vi
) 3 X UJ OS :
< 3 < —l ui a
J _l OS UJ H Hi 0
ca.4ixu.zc
3 X uj <
j X X uj
: VI VI X Z Hi a
4 ui 3 X C
m = a.
o= 3
Hi X X
z a.
uj 3 a.
z <
'ul VI
c H* as us
< UJ 3
VI Hi U.
as z
a. uj us
4 Hi X 3 < Ul
J X 3 3 X VI
>4 U, X Hi u.
: x vi
J 3 X 'ul 3
i UJ UJ H Z Ul
. X X x 3 a.
3 uj
Hi _1 H
<3 0.
us X X
UJ z 3
a. 3 os
3 3 a.
Number 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 9
249
x 5-h -i -a
3 VS a. -o
2 HX E
x q <
« ys -/I
C d 3
s x ac
Si 3 «
VS 3 ?■
4 -a: <
3 H C
3 4
H X -
3 1 = -
O 3 f.
3 3 ;
: 3 * x
i j 3 J
« X t_> H
) -^ 'J '/J
J d J
j -vs 3
sauiH)
X U] !ij z V) z
JOW
3 vs o
VS z f—
3 z o 4
JHOUf-
O VS
X
3 3 -*
J
O x _j
uJUlH
J _» *—• t_>
J O O 4
1 SI < X
) Z 3 = 4
: 3 4 x
s o x o
f- x
o z
4 o
X O
J Z H :»
►H 3 Z 4
x o o
Z O 4
3 3= H
O J I <
x a as
3 x x ~
I H ~X
Ld — —'
Tt VS -
NUJO J
4 X F-« X
VS JU
3 vs j vs
>< ‘J H
3 vs vs 3
a as
-J J H J X
—I —1 ■•<•—< O
HHSJU.U
X X 3 Z
J C_) C_) C_
V) X X J 3
3 4 4 _i 4
-1 d d 3 US
O VS VS 3 X
o -ia>
It; j d | jj
O JJZHVJ
UHHOUVS
td X x us -j
3 J J X
j 'j q
h vs c/s < vs 3
4 >—«—*
3 3 3 x x
TZ 'x X 4
UJ 'J H H E
y H X H H q
t -* 4 4 z z
H U) Z Ul 4l H
x xj 3 3 y
I U X H H V)
int^ , xs'T>«-
77077^07777
J J1 'J 'J 'J LJ 'J J J J d
HZZ0exH-4HO3-<
j o o q u '/s a y q b vs
vsoo*x_io/Sooz
J3xaxx07I30
-ZOSZZZZ-t-tZZO
ooooooooo as o o o o o
777777707 777700
3 d d d d d d d Ld Id d d d Id Id
q VS J 3 4 ^ d d -J _1 4
4 d Ld d Z H VS VS (-* X _1 d X
OXV5j-/)XtdH H <X < < 0O 3
JXXJOUUJ3 3 d Z 3 • J «—
’ vs /la. jxx u 3 z sc a 3 3 3
• q q q o o 7) vs q * z o x _j _i vs •
o ~
o
3 X
as u, a
H X
X HH
4 3 z z
*—< H 3 3
C/S *-H
X VS VS
X s z z
4 Z OS SC
JldHH
XXX
vs o as
as (O 73
o as o
o "s as as
o 3 as as
7 777
'd td d'd
o m/sBxi
• 3 3 o o
i 3 as x x
•- --33 Id Hr- ■
3 -0 33 -
so ro a
X 3 a :
x x a. >
3 4 X
d d d d
_j as
_j 3
3 to
d X
as 4
3 as
o 3
t-H X
VS 4
H X 3 Ld
J M O X
H x'd d
d X z
CM lf» "VJ
3 — q\ — - -o
X + + + ♦ ♦ ♦
o X X X X X X
x o o o o o o
3 3 3 3 3X3
7 707000
d d dd d d d
Z Z • X O X
3 d Ld ’d X Z
X X X X X X X
o o o o o o o
H XX
id •
H H
J X X
J 4 4
OHC
3 J
SOTS
: z z c.
J d Ld <
> d < 3 Q (->
L O (—* 'd —I d d 3 Z
*« Z d < 'd 3 D *H
I 3- as Ld O Ld <
VS rd m i—• |—< t—,
JJHJHZSJU.
JOXZXXX^-»d<
)OHdD<JTT
3 X X _l 3» Cd O X X
u<xuaiiiidOiH->« jizo x3a
X X E X X X
3 — CM-
3 o as
0 3 0
xxxxxxx-nxxxxx x
CO ^03 Or^XO>»< 003 d Ld 3
030003 3 300303 •-
00 0 3000 330030 O
X X X X E X
~ \j O :r _n
0 0 0 3 0
333333333333333 3
7000700070000000
d d d d d d Id d d Ld d d 'd d d d
3 3 3 3 3 3
7 0 70 77
td d d d td d
_ixxx:— oz_j d — -\j -t ^
3 O H DZ a IU ^'d HJ S o h 300004
- Z X X td Ld Ld < X X X 3 > Ld O XX ••• q as 33 3 Z
II
II
II II II II II II II II II II II
o>- , M^7in>x) T'-t a
30303033303
30030033333
30303000300
03 d Ld O'-'VJ O =T
0333—
3 333 33333
333330030
X O f- X O' 4
Oinoo
3 0X0
0 3 0 0
3 3 3 3
0 0 3X 0X0
r> x x o q o
3 3 3 3 0 3 3
3 3 3 3 0 3 3
O-^^SiXO^BJXXOOJtd O — M X 4 X
3033033333.3 33333 —
3000303030003003 333333
3330303300033 3 33 3333 3 3
• O 3 td
q 4 'd X Ld
U X O X
H* 4 X O F-
X t-« a
Jh t
m r
4 H 4 X c
S X z > = ►
J H 7 < h :
3 H O Z 4
X i-l
'd
X X
JHOi
» Ld X :
X X o
J X o •-
) US O Q 3
JJ O i
3
O td Li
x 3 :
3 t
X X
H X
o
td o
3
3 td
U. X
e z x ■»
3 H < &
7 = -
< O X
0 3 =
3 O L5
X X z
X M C
-HX^ti
X 3 4 a
5 X h x a
5 Z O X -
4 4 I t
3Xo-3 =
J H* 4 Z >-
- X 4
< td O X 3
X M
>-> X X
X Ld 'J
4 4 X ;
x X H -
td f— t
■^3 3 = >-i
e x =
< ■»
C X <
x Cd o f-
3 X
td O C
O M
SOH4
- Ld O X r
H C3
i O td 4 4
d X (J *-i
7 td 4 F-
7 > 3 4 3
C td X Z O O
7 Q 3 4 3 X
4 H
C td td id 4 X
J H> X O X .3
7 0 HOh
3tU>HO
3 X td 3 4
J X H Q 4 X
C 4
-• Ld X Id Ld Z
XUJHHO
“F— 8-* O 4
O X 3 4 F-* td
C X = HZ
- X x O O X
O < H Z 3
E O = H
-I O X td
4 td -j td oe
td =
td 3
td 3
Ld O
H Z
o o
3 O
o a
X «
H X
3 3 td ^
X X X X
O — CM rr,
O O O O
O O O O
0 3 0 0
7 77 7
3 td td td
3 — CM O
X X X X
td td td td
3 3 3 3
0 0 3 0
-X X X X •
3- _J
H X
X 4
— i—I td
td 3 H
sz>zu
XOBHUSQ
X X X td X
OX* U Ld
X td td td o z
>*HO
» x X o H
ItdH LkJ X
1 Jh 4 4 4 3
S 4 X H td td 4
J I 4 4 X -J *—l
=3X3X03
: X X X X X X
J 4 0O o o o o
S O O — cm 4 -0
J O O O O O O
30000000
77777777
td Ld td td Ld td td td
td4HxX^:X3
X3Xtd> X H H
-H X 3 X O X O 3
as x o x
H o H o
X H X H
d 3 d 3
4 4 4 4
■- H H H
4 4 4 4
3 3 3 3
X X X X
4 4 0 0
CM O CM O
O O O O
o o o o
7777
d Ld td Ld
H vH — f\J
O O Z Z
X X H H
• 4 4 X X ■
H td id
> O _| X
J US Ld
O H
3 3 X Z
O O H O
X X Z O 3
H H O 3
Z Z O Ld X
O O H 4
O O H 4 Z
*—i X "d
a 3 3
3 .3 *-« 3 H
as O 3 4 X
XX -I o
X 3 X
X X Ld -v x
3 3 3 3 3
Q340H
O O *-i 4 Z
X X 3 X -i
X X X X X
— — A1 4 X
3 P7 o as o
o o as o o
0 0 0 3 0
7 7 777
3 3 3 3 Id
O 4
3 3 3 3 Z
3 3 3 3 3
X X X X H
X X 3 3 Z
-X X 3 X >-l •
-US —
X3W!
O X x c
3X0
3 0 0
H O O
4 07 on
Z II II
H V V
3 - *
3 O f— L
0 0 4-
mriz
A /\ H '
X X X X X X X
ornama34
0 4 4 0-000
o o o o o o o
0 3 0 0 0 0 0
7777777
3 3 3 td 3 Id 3
3 3 X 3 X
>-l"*3 3 3X'*;
X o X 3 X 3 X
O 3 3 X X H X
X X X X X X X
-X X X X X X X •
'VS vs
X X
X X
d d
Hi— 333333
44003000
XX444444
X X X X X X
3 3
44030300
-I — O O 0 0 3
3 3 — — -0400
XXXEXXXX
0 4 3 < 34 X 34
0 - 0-0 OCV-ICM — —
03000000
03 0 00000
7 7777777
3 d 3 3 3 3 3 3
— -VJOOOOOO
dd — — -7400
HH333333
44000000
XX 444444
• 3 3XXXXXX ■
X 3 3 C
J X 3 H :
: o o z a
J 7 q
* Z Q
3 3 3 3
H OS X
i-l 4 X
Z 3 O
M M C/S
<-> H3 S3
3 Q X X
O • 0 3 x
VS Z X X 3 3 X
C/)KO X X
►-» O vs 3 4 3
H 3 *-i 0 3
X 3 X X Z 'VS 4
3 05 H H *H 3 X
O — CM -O
O O O O
0 3 0 0
O O O O
— CM 4 COO O O O
3000— (\J4CO
OOOOOOOO
oooooooo
4 4 O O
CM O CM 3
O O O O
3 0 0 0
— — rvj 4 ts
0-0000
o o o o o
0 0 0 3 0
O CO X m X 3 4
0 4 4-0-000
o o o o o o o
o o o o o o o
-o 4 id ts 4 -\l i, 4
OO-OO-OAJ - —
3 0000003
33 3 33333
Page 10
250
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
M U - (A.
- - ac
- O Z < L
-jJH.
- - z x
luUX
juiDz
-H LU -
lb 111 Z 'i] .
.J a X x
U c
Z Z X X C
C_> U <
-»-» t/) a: •
- z <
z z x z ;
O < 3 .-
X u-4 o b-l
:h o h -j r
xx o z x
x z z
13 3 Z O <
XXX
- 1-1 --
- -X H
ac ac x o
O O -x
- -Z H
- - uoj
~ ^ -.3
0 3- I
OOU 2
< < 3 X
J1 03 OH
x x
3 0 X
o o ac <
fOOUO
-a - j > u u ■
- a. vh -_j </»
J LU - X ' J - *—t -
0= —1 —J'3 —1
O - -Z •>:■
- Z X ►
- o—io
^ X
-l U lb j as *h f j _J
- - LU
X f-
: O <
J X U
x O C
U H f"
-CO
• 9J>
) u r -
< x i
> X Z :
* X < •
U 3 (_>
VO z -
o tu -
JHQJH J
“ O X _1
1*H!00 Jl_i;
Lx LU X U S
- —1—10- U U 33 33 33
X - j
3 X ”
iu a
- aa c.
j -i x
-co o x
-<XlO
J Z X M
- =3 X CO
• —1 —1—1
LU LU 'U
21 33 33
- — H 'J J '
XOUhZ-
o c u <c —•
H -1 _1 X S '
j O XU O
u lu o a _i
X LU 3X-
O-tXUCO"
■« a < h« a ix :
X -x
Z CO X < u
y> i i x
h a a h h
a -z o o
- < << x x
-x a j o
LU x
LU u _1 _1 LU a
X X
o o
X •
X L
cm "A9
J j -3
X X X
■err
UNS'UjI
Lf 33 T 7
a 3>bb
9999
M — CAPA
!3 » S T
n ■-- < r-
? naa :
9 < < <
0X0— =
X
r
— «M 9
=r n cm
O 73 <
9 3 0
CM 33 <
n o o
o r- x>
o o j
x x x
•a o
X X
X E
i (3 33 <31
9 9 n
Ol o <
>n 9 o
0333 <
993
9 n <
9 9 O
■ o o b o cm o o
3 — cm a 9 n o
03 — — — — — — —
» ^39
X 03 x
9 9 9
•j aua a
x x x x x
E E E E E
CM X X X X
99999
-CMXX-
7 J3 33 1(3 9
X CM 03 03 30
9-C39 9 9
n .r\ 9 9 o
r> 9- 9- 9- M
r— c— >- r- o
O O 3 O CM
>- -O 03 3
X X 3 —
— 73
9- 9
CM C_)
9- 9
3 n
AJ 9
3 X
M n
x —
9 CO
X X
9 CM
CM O
n cm
o —
a 3
x o
E E
r> 3 03
CA AJ 9
9 3 9
oaiirt
X 3 03
CM M 9
3 3 —
<M CM 9
9 -X T-
-O — n
X
E
3 3
CM CM
9 3 3
AJ CM AJ
9: «< 3
3 3 M
< < 3
a a m
3X3
3 X CM
Huaib<vi
1 O X
> O 3
> -X
: o x <
X “« X <C (-•
I z
3
X o
< Q X
X z O (-•
as -X 3
O X X
3
CO (-
X X
) *£ X
1 h UlX
X X H
(-• Z
O 3
«S U
x n n
9 9 9
n o 3
9 9 9
< 03 03
3 9 9
< O X
in x 9
9 9 n
coo 9
n 9 n
< o x
3 9 CM
' X 3
r CM
003— a <M 4 Q N < X 33'”0 U O "M < X nXXCMXCOX-c
03XOXXOC09 X X < X O X 3 — 9 O OX U 3 *
* .X .X X .70 9 9 »=*■ =*=**» =•■ =» ^ ~ - - - - - -
XX— 0X3— aCM<XN<X03- OOX"M<XnXXCMXCOX9XU3Xt—
— Xn>-03X3XXOr09 X«<XCJX3 — 9 X XX U3 — XXX03XXX
OX-OX-OX X -0X999999999 n nn An -An X X X X XXX-ox
333330303000X033333333330333333303
— XX 03 C O U
x n
3 3
X X n- 33
3 0X0
— n 9 cm
3 3 3 CX
X X U 3 — <X
3 U lb O lb O
X X X 3 X X
AJ CM CM CM CM CM
r- c— :»• c—
3 3 3 3 0 3
cm 9 n r— x
CM — 03
<x o x
3 X -x 03
O X o o
03 o X —
X XX 9
c-— t— r— r-—
cx cx ax co
►H X
E Z
z u
3 E X E
3 X Z 3
z z a. -4
3 < 3
Z Z X -u
-n t— x x
o o
Z 3 z 3
x Z < Z
X X O X
Z Z {-
X 3 c =
X lu Z
Z X. XX
«r<X33t—
X O J 3 O *H
X y) -H z -U z
O X X 3 z 3
3333303333
3333333333
3333333330
X X X X X U X X X X
z a z z o j
x «— < E x v> y> y) yi /> x
a x o u o x x J z 3 --3 •
xr~xoc-=zao3xx x
3333303333 3
0333300333 3
f-A 00
O 3
lu X
3 3
3 3
3 3
u X
E X
o n
o 3
— z
< o
x o
aj
X z
X *-H
Z 3
<* X
z z
o o
«< <
X X
o a
3 3
e r
E E
X X
3 3
3 3
—• 3 < ’ J O J 'J
yixx<zx<o
3 X J ~t X —
X Z X X X X --
XX <3
ZXZXM3Q-
X X C << 3 E X
Ih 3 X >-4 X
oiBwaxzib
i i
: x
z < 3 O < 3* X
<HZHH«Z
X C <X 3 3 Z *H
O 3 X < Z < X
X X H
NU<
►H Q
CO X
3 X
os X
X fr-« o
x z co
3 X
z e a y> y) y> yj /3 yi y) y> x a x
33333333303333
.Z X •• J 3 _
ZXXr-«:-»Z3XX-
O X 3 Z X -X 3 X x a
<C 00 3UXXHH’/K
XEEX3V)33za
XEEOXX<Z<-
x a n
•X — —
=» 3 3
O n 3 3
cn 9 A X
3 3 3 3
3 3 3 3
< < < <
X X X X -
O X z X
I 3 O (—
I CO X X
■ *-o O O •
13 3 3 3 3
) 3 3 3 3 X
: «s: c < ■=£ x
1 X X X X o
X
> O 3 O O X
13 A 3 3 X
- -09 n x x
IZ >s
X 3 z
x x >x a
x x y> u
X E E «
3 3 h-« U
O X f-i 3
X E M Z
iz X X X X
X z z z z
X 3 O 3 3
E X X X X
3 X X X X
----ca---
'/»*/» </► • -
— — — a on cm r
!M o o o n — *■
X) >M 9 9 CM CM f
• 9 n n n n — *■
39999 -O 9 -i
Ennnn t —90
999 9C/1C X3C
X---- 3---
X X 3
XXX
(-•XX
X - <c
z x -
I X X
3 “X
3 Z (-•
«e o
-z onx 4
: -c 3
> 3 3c
i x x x <x
: X 3 m - -
i 1 < - -
• 3 X X X X
> 7Z x X X X
C <X 3 -H - -
X <
X 1-t
-3
Z - 3 X
x z r- o :
00 ---
33-A.Q39nOXX)<Cao3
33 3 M "M -A.'A'A'A'ACA-AOA -O
33333333303333
3 3 3 3
x x r— x
0077
■O CM 9 =
CAiACAO
9 n n a
rAPAc-A -c
9 9 9 =
CA PA CA n
n n n j
"A PA CA P
CA PA PA
090
PA A PA
3 X — — 9 O* 3
J 9 9 9 9 9 -M
3 <X OC CM OOA —
J39.A9-M9 9
) < a - o a
J 3 'M 9 CM AJ 9 3
3<XX3CM3<
J 3 9 9 -M A n 3
e 3 9 A » PA PA 3
- o n 9 9 9 ^ a
AJ M
-X 3
3 \l
CM 9
< 2%
3 9
X 9
3 9
a r-
o 3
0 3 3 3 3 3 3
30000003
c—a — nAaxoo 309
=CLJ03— AAOcX'XXX
r- T- r— ,-\j P\J -VJ -LJ AJ cm AJ PM CM
333333033330
Number 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
251
x
3
a o
a c
C 'C
ja c
a 3
i. a
f- x
u
-0 X _l
K/lHHJlINf-.
Mo:>:»<30za
• -a. t. X o X a -s x
UJ
o
o c » » x •» x »
t/lKMQ ouou ;
•OKI X X X X -
w 3
-J 00 x X
—• X Z 30 OX H
x z x a <\j n u. x
< X O-J O 3 MM
•-juuxtowQioto za
a — a X > *s X 3 x o 3 O o
o - » “3 * -a « -a a -
xcxaxoaxoaxoa
o uj
X =»
-Ox -
X x
x o a
c a a
x x o
o - -
(— o a
MM -X
o x a
o o o u
a a -
x o x -
X UJ
X ■>
-U <t
i- yj
e */j a a a x ox
t t oxo'*-i»X'*3oc:«
--a oaxa-WHii. »a «*-»
ja'j.o'u.a.oa.oxMoaa.aor>i
UJ <
a x
coo
-J z a o
h uj n uj o o
x a. o a O x y>
O X O n Z X X
uj - - a a a. - -
yjoau.'Njooa
X M U
o ZU
a -» x
tO>xx4>xox< :
•“Xaaoxaoxao-
xcc^»c:»x<axx<=«x
_iooxox_io_i_i_ioo-9
uj a a x _i x a a
CM-«_j-«_ia_jA.>-ta_i*-«;»a.<:»_ja.
X > u < »cocOza<z o O x o c X
•“X-ioxoa.ox<a.o<xxoxo-9
'non <
o o a a
m ui uj a *- in m o*
oo—ooooo
'Xaau.fNjrr,^-!^-
a a a a uj uj uj u
r—- f-~-c— p— t-— r-—
O'OO'OO^OO
a
a
p- -a p- a a p-a m m n aj y\
a o =r p-ujt— a — niooo
— o r— o o — o — —
o o o o o 0 0 0 3
aaaxrTv^Lncanujij.
o 'n^uioooo»09»
ui — —aa—auj — a< —
''A ai — o o — o o — o -a aj
3SS P- — O — — 5SSi
ooo o oooaoooo
a o o uj r\i < a n uj x n o a —
nao-ocro^-aa-a o u .o r\
— a a uj a a — ac--a a
— o o -a o a — o "A \j — ooo
a o a t*- o o a
o o o o x x 3
T»on*-n o — -no a —
aaooo o a — u. — m
a — a a o n a — o n a o m — o x a -a
o*-o oou.ou.uju.oa^'x.x^-oo
*J'< a o a a x o — aj n
UJ U] UJ 111 U) Ul'il U] x x X X
P— p— P— P— P— P— M P— P— p— p— p—
oooooooooo a a
o a a a — pa a y\ a a •- »
xxxxoooooo — —
p-p-p-*—-o-oaooooooo aa
ooooaaoooaoo
s< ao r\ias< ao a o o> o
— — — AjAjrM.Aj.M \J a a a a a
ooooaaaaooo o a a
ooaoooooaooooo
x — » p- a* o oo — a^->-o\<aoao
a » ^ =r » ^ ^ nnnninnnnnin o
o a ao oaaaaaaaa a ao a a
000000000000003000
o o a a
o o o o
x o nxo^M
o r> o x -- o a
a — aa-vja —
o—oxoa—
a n o a a o m
ooo o o p- p-
a o a a o o o
o o o o o o o
a c t'- x
Mao
o y> _i x
O Ifl < H
•-« Z >
a o < -
< X -
x a <
o a x
s a as xx
c a <* a x < x «x
- _ * a x c o x a x
-O -O -O -OX -O -O
CCMCMCMCMa C M C M
HIUJ< ** C &OIC
a x a m a m x o - x
oovjAjxyjaa -o
uJoxoaoxaacM
U H Old M
o x a x a
hi/)uiau<
x < a a a ^
< - O -03
a < x < r a
j x a x x
j a a a — — x a
) a o a x a. p- a
*0X000X0
: x x x z z o x
a
t\j
a a x a uj x x a r <
a a a x a n <z a x a -r
cyjaoaa — ao-nao
xoxxo -axxo*
Mxxxxxaaxoxt-
a *h a *h
a x a •—< a x
c c ^ < x
o x o x o ->
•h a *-i a f—
> c > c a
x o x o x
S —1 X i-H •—* —4 —< X
c<cOzxoaax
SOXCO-9C<-j
►H »H m a J J H N H a H
aza<r>j<<zz>ca
•-<Ooaoo<-sxox
a —t M C r-»M
a»o>oa oa
•- x o x o a ox
aCMCMXXMMf-
aaoaooozou
•-a oaozzcoa
XC(-<CM-<aC>-lMX
Maoaxo>cazox
•-a oaooxoaco-s
S N P~ p~ C
a o o o o
O AJ oc\jaOAjp-r\jx
OZAIJ O? 0»M
aaaauaaam
'OO -no <^o rnuo
-Tsaao^AiriJOCQ
r— >- r— r~- p—
oaooooooo
a <m < aj
o=ro=r
a a a a o'
mornoo
o <\j in p- <
o o o o o
p~ p- p*» p~ p—
o o o a o
=r x c a p- a aj
p- oop-a"A^r
>n x x x x a—naco'OPA
x — — — — oxaaaooo
-noaaaoro^r-oxjxau.
O O O O OP— p~p-p-p-.p-.p-p~.
p— mp— p—p—p—p— p— p—p—p—p—p—
ooaooooooaooo
p— p— p— p— p— p»
o o o o o o
X ro X X O <M oarvi
0 0-»<\l rnOcOf\j»
o"Aa<aaoAjao7'
aaooooao^oo
ryj3'Ojiox(V»p-3»u
JOOOOOOOOOO'O'CT'O'O'
P— P— P— P— P— P~ p— p— p— p— p—
00030000000
» 3» A| 'A
AJ O O O O O
a m a m c "A cr<
'Aa 'Aa rn a o
a x — .*a n -o <
<»*c c < *<
p- p- p- p- p- p-p-
a O O O 3 3 0
— — o o
o o o o
3fM» ■AOOP-m
AJOfA 000X0
<^<fAooomo\
-AarAOooaQo
aaanincoiaax
cc&am&cacQaj
p— p-p-p-p— p-p-p-p-
000003000
T (AU.< J .'A'A-
a o o a 'A x o n
B^-moacO'ArA
oa a o o "Aa a a
vn x -jn x a o •'Ain p—
Page 12
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
252
a
z
'J H
CO X X
•c z a
• O
= Z Z
_J O
_J Z X
o ^ c
M O X
o < o
u M
x CO o
M M
a h
= O M
=3 CM
X — X
U'J X
C (/)'/) K
— z X O UJ
«a *
3 PO
m o
z o m
\ o.a.
a.
o •< <
o o
t< <
OHh
« to CO
X 9
x — xx*- x
OU X O • J <
X V) C/J X X C/5 X x
r^irojuoiu
x - . -awx
u-o *- ayQu.QiMauau.auaii.ii.H
z>x«<xxz>x<r-»x<or
“JX-'O-SO-jXXU-dXXUX-j
_j uj x —
mV) X -
U. O X O 'J
. J O CO X V) C/5
■< O X O in * r 3
v) « - a m - -a
HU3U.IM
o a x
o x M
o V)
uj o < -
rM -dhtt.
m X CO CO V)
Z m Q _| M
M X < X X
•-_i a to a
u. JUJU,
uj < o
x _j m o a
<OIUI
X M U
COQXXU,
I I X UJ
a o ■< ■» uj
ZhhtOZ
< a O Z M
X < Z < _l
M f—• t—• M H
UJ X UJ UJ ’X
cO CO CO CO CO
J uj :d uj UJ
UJ O'JOQ X X — 3
u!a_j_i_ia_j.jxoca
<axxx<<zazco:o
xMMcoaa:»zo-*roiJ
co x o z x -x -x - -a-
<x<K<j«<n<t’j3u.:
<<<<<<M<M<MMX3
ZMMMMM»M-»MC»><<:
XCOcOcOcOcOZcOZCOZ-JO'd
a co
x o f-
- 3 :
I CO f-
a uj
Z X K
- - a o x -* z o
4 M N M «
: x z > f.
: o -» x c,
-*M_JXMMIN|-
»X<Z<XZ7
E JUTXO-Jl
p.. trj
a f-
uj cj
a <
Z X
a <
X X
3 H U X ul
2 ^ x rax
COM— a-O* - CMXO-J
- a co < « a -o 9- < -xx
uu.axou.x - a < Z O
-» —I -J X _J
—• -I CO M M < _|
<<<MX o x o ;* m <
JUUTXUdUlIiOU
.n a —
o o a
a uj x uj
a u. o x
< a u. o
a a a —
y> C71 C7N
a a a a
90 3>
a a o a
a :n — m -
■vj a < a--- .w
• a m x AJ uj
o a — o o
903* 9- a x
-< aaa aa a
T3(Maj>U.ftt)TNU ft —
~ an o a a X a o a n
... >.« — q -ox — a — o
a a
a a
a c_> n x
— n a x
a
a a
<n avn
a x a
u o a
- c_> o a — a 'j
-\jnr-<aar\iinr-^*aa'vj n x
— — — — — cmajcmajcmajooooo
7'7'aaO'3\7'7'aC^a'aa3'7'7'
aaaaaaaaaaaaa aaa
a u — 9- o n n\u u.
n-0 9999999
aaaaaaoaa
o — — — — — — — — — — a
o aa aoaaa a o aa
o xx p-x<ao9-na9';y.>-n
a r\j <M noo~o-o-o-o9-oa<a
— <r>PVJ — X'MAIPVJCMAJXCMXAIX- a
c\jpnrNjpn<'n"npo-n o*j'o-*j'oo--a
- j o 7>
opo9c-<*Xjj*-»N< a
nnn nn no o o ooo
a t*- cy» «- 9 a o>
a a o a a a o
— r>9--u.»Q' J .t>-0'Oinf\j
oaa — n9-cr\xpooxoa
uaj<auiryui-yuj.-3m
aoxoaxaco-oa-oo
a\ naNji a
a a a a a a
cm nj t> m n x < — r> a-
=r a a 3 a — < a a -o
x \j x - a a < x a n x
x a a - a o a a a x u.
aui-’o«co<aii.'M9f.< a x ai T'-<aaAino
w wi-i-i-i- ss»aflas)co»o' 0 'j> 3 N 31 c iac^txxxx
3'7'3>(7\3\013''7'3'TNT»7»5N.'7\J»3»0< CTi 7> Js J'7'>3»7\3\7\7i
aaaaoaaaaaaaaaoaa aaaaaaaaooaaa aaa aaaaaaaa
— r-
a a a
a x 9 a
o o x o
< j aj a
a -o n a
x a a a
a x x a
T> :r\ 7\ :t>
a a a a
UJ M
M O
a c
< X
:x X
« a
• o
a z j-
< m a
V) a. «s
•/) z
X X <£
rax
<c o
X -x <<
x a x
<c a
X X
X <£
C M
CO X <C
r a r
c a
XXX
a. x 3»
>- a x
x x
X X X
X x -»
>- a x
i-* a z
x x >
•-ax
{-OX
X o
x X
O (-
a * o c
a o x c
x X {— Z U
a x
us a a -o
x x u. o
m - -a
a a a u. o
x ct* x x t— x
z a a x aa , <
xxcocoxxxfco x
'x-»rax-«ro *o
x - - a z - -p o z
— aaau.aoaU.x-
xx «x
<s *c X X «* <
X X - ’X U. X =»
u o x o x t— a
j m a (— - coomx.
x
i - X •* X - X
x -a x x -a
X < {- X M < H
x «* v: Jo x
xxx aaa <c x
•— x a co x x co v) x z
xaxanvc^raza a
- - an < - - ao x a
<aaxrvjroaxxM<x
. < a
j x a
XXX
I- a a
x a a
x < f-
a f— x
xxx x
x a * a
- * z a a -o x
xaxrxaa xx
JXX<<{-
*< o r z m x
a x -j >< a x
z3»x<xr>jxz-»'xzr»>«: a: a r
• -rxoaza-urxaa rxax-s
o ox _j x x
-n M M M M xco — _jq— i ■—i 1 X
tox->ixp>jxaxaaa><o<<-»«<ru
•-a -> a -» a a a -» *-x r a x a r a z
<JMP4MMXXX<<M
c<xzx<azxMx
Joaar_jax-sx-/)x
< z < MQXC»X<M!N|XX
•zM<x<aaoaxzar
: mo xaxxxxazx-j
n o t> a a a
— p- r— >- >- x>
ox o x x »
a a a a a a
oa o=rao no
aa a aaa aa
9-ana <-ao»<n9 )>< n
— n a a aa>a^a<axa
x — a x x x c\j x — a x x — -» •
a — a x a 'x a a — a a a'
— xoa\Xax — xoa«ax>- 9 n
OSOOcO O O 7171 > JMJ < <
xxxxxx oxxxxooxxx
aaaaaoaaaaaaaa aa
<-vja-vjaax-vj xrsj Xcnrvj
3939 MBS 9 AJ 9 o rvj =r
xi<x<»j<x< nxa—axa ^
x a x a x a x a 'x pn a x a po a o
txau.iM9p-3» aaxAjxxxa
<<<<xxxx aaaaaaaa
xxoxxxxx xxxxxxxx
aaaaaaaa aaaoaaaa
a a o 9 - a a a
a a a a a a a
o o n x n t> a n — o
'-noxxiaao n c—
a «— a x "vj x »- a •- x x rvi
a •— o x a a — axa<xa
OX— 9 O 3> aj " M n 3
ooaaaaaaxxxxx
xoo oxxxxxoxxo
aaaaaaaaaaaaa
■o a x a x a
pp» a x 30 xx
n < x x o cm — — m <ja —
x x n — x x cm — x ■— x x o x
< a x x — cm nxT>< axa —
xxxxxx x x x x x x a a
XXXXXX XXXO 0-0 7171
a a a a a a aaar> aaaa
n p-
a a
Tl o\
a a
Number 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
253
'X X JS
•JHCQ X
< z x h
-J H 3 Z
a O z
H <
< > Z
H < O
V) a
<
t-«J c—« t—
-1 ■< C/1
Q Q !J
C/1 H
z UJ
O -1 -
uoto
5 </l UJ
X H - Z Z X Z <
-c/ia«*< J)Oi/)H :
< a z - oxo.Ho.axx*
z a x
a O < Cl.
HfflCM U.
KU'J U.
t CO H Z K V) V) li.
J 3 z < z X a 3 :
- a < o - -a -
iix'-uaii.aaaa<
c/l
Jc CO
<5 -jj
■4) >-
z a z
*-t a O
JHI
Z CO Z 'X H
HOX
til H a;
c/1 c/1 H
>- o
z <
< H
H CO
H 3
UJ H
CO CO
til U1
O' Q
> a o o. o.
C CO H 3 Z - 3
> 3 H tOXH
C'J<<tflXXO. - CO
z o
cO -
o. <
«M X CM
+ til +
O-J z _1
ja o as
t4.HO.XH*
H Z O O. Z
O Q H -X
< to X < «
'll Cl.
X X
33 3
O O o
HZ'
O cO (-
ZO.C/
a z
—1 <
a x
h o
o z
1U.4IH
X f-
X -
O 3
Z CO
Z X
o a
a c_>
ui
X H
H H
til 'il
CO cO
X 3 -Il X
a -I CO -J o
CO (4. a H X til x
aoazxc/irz
a -a < -xQ -
^.4 1£(J
' 5 X X _J -1 X X
XC»*-« M tOlO JHJHXO. 3 C 0 H-
ooa.rxo.M 03 < 3 <azx o :
xxoxoxn.o.oo.cja.t-1-^a.o.x :
J JZHH JHlOXX :
<<3:»x<<o30E
ooax_lo_|o.a.ai
> Z o m o c.
a. a < < z -X z HH r
j x axiNiozoa .1
>XS-*_ 40 -sZ>-«ZO-
* X _i a. H _1
» H X X X X
: co co x _i co
< < z
Z H O
X CO z
o _i z
z X --H < —1 O H H _
s :» h < > x «
TZtSlUHX Jl
► X<^H-<>H«<>
E JUXCOUttOOX
a a
— o
X a a <
til HU, U
t— x O' x
XO O X
< < < <
0 0X0
(MOO 3-
ix < in n a —
Ij. u w u o u
til O co? 'ACO
•O r— H t— H r—
<<<<<<
o o o o o o
iku a iij
t— r- r» r-
< < < X
o o o o
CM < IT* a
O O O O'
in ui ui a a
Ul O •— o C_)
•- (AJ 3 O O'
cOtO *0 3) 9
< < < < X
o o o o o
co O a
OOU.
OM^tflll,
o mo a
a — o— n— oix — < m a < a a o
o-uouuosauutjuouiii
H- X H H- < X
o o o o o o
a o' x cm o oo a
-u «— < aj m 3 ^ a
< to a < a q o -
uui'-7'-coj\4auii.ocno(j'u a»- ^Nxiauauio
xx) 0 ' 0 ' 0 ' 0 ' 0 ' 0 ' 0 ' 0 ' 0 '<<< < < < sK a xxxxxxxo
<<<<<<<<<<<<<<<< *t x xxxxxxxx
oooooooooooooooo©o oooooooo
a
o
a cm
■ — • • . m
"l < P- < — m — u cm
m X O a AJ a a O
rsaaoauio
-a — —
5 0 0 0
3 (M til X
} 0OvO 43
o o c
U. < oo C
(i. ro<o c
muicMCMo.-
U.oOrnrMOCMtM<oOti.O
(J "O *- CM U, CM •- r
on o- vO O'
uouu
X < X X
O O o o
UUIM
o o a
< X X
o o o
tflOC
a a c
X X -
o o c
o o
•—ax
o CM <
ui cm a
on mo
m o
o o
O' o >r»
O f- o
tAH< a j
Ul Cil til (Il Li
<•<<<*
O O O O C
-f> O — C— — H-
o o o o o o
o'aiau.ua-aao'
o x o a mo'mcM<o
uir-aui.-Mauicsjatii
o—ommommoo
=r oo'U'j’-? ootu
U.U.U.U.U.OOOOO
<<<<<XXXXX
oooooooooo
c- z
co UJ
CO H
ui o
< H
—« UJ
a o
< H
M O
a <
Z X
CO C—
z o
X H _1 t
o a < :
< O X X > ^
<uiaxa<x^
> a u. o u. ui a
a < < <
cm ui o
ui
. a h z >
* c x o
* = a o
ui cy h on a tii
a co x < x x
o a ui z ui h x
< x a a a ui x
a - o -o co -
Ul X Ul Z x co z <
: a z x :
- O ‘ * c
c x o a l
O H
H CO *-
o a
•*< z z
a h a o z
Z CO H H -
o x a a o
r o co o
x o Ul
-a co
a ti.
z »-• o h o i ui J
X CM Ul Ul CM rj
a a h
- o o
< x z -
a h
ax c
o *♦ f-
t t— a a
> o z z <
. < o o =
o x
o u.
z u.
: - a
> •• •-«
i - a
a h m
< a a a x
Z X < O < X X
n co on « « • «.
<zo aaxaaxa
■«x>>-t'-ia><
: o o > x < o h
e a x x a a x co
xxaoxoo-
at—• h-hhx'—«h>—«{■
> o > o I > 3 >:
zxaxou.xox:
a <
■/an
. x < a
H H< «
> o a c
r a a :
. z J t-t
) x < z o
. -» o o -
a x
Hjx*-»ox-«--«a=»x>
<xozao>x<020
jcoo.<zxxaax>-«x
i ••
i o
• -a
< UJ
Z X
• a
CM O O O'
o o o a
o' x _n •— no- < u. -j .
o x* o o o o r» vT> j
O' *- <
o o o
' AJ U. X O-
sr a u. ■
m?o>to< 3 u'i.
ooooooooo
O' O' O' O' O' O' O' O' O'
ooooooooo
c\i ss<ui>-? axxaoAirs
aaaaaa x x x x a a u. u. u.
O' O' O' O' O' O' O'O'O'O'O'O'O'O'O'
ooooooooaoaaooo
O tM ? ^
a c_> mca
a m a m
-n a ma
amama-
maonao*-
3!M»9fl<t
o o o o o o :
<<<<<<.
o o o o o a ;
H- < H-
o o o
a o' o
— — Ai
a < a
o o o
aj a a
nco*-
a £> m
o x o
o m x o' o a
aj o
o a
o'» m
a a o
a — a
o-o
— no
CM M AJ
XXX
a a a
AJ AJ < T(
a om rt
a m<
~n a m x l
O'Qaa*-
aj aj Ai m CV
< < < < 4
a a o o c
< H-
O O
mvo a
in aj o
- m a a
. o o a
O O' <
_ m a- m_
< a < a <
o ■ ~ ■ ~
m aj x
mx m
I*. m .a m
a a a Q o o o
o <m m c- < a a
3-33333^
<<<<<<<
o o o o o o a
ax m o o
am a a o
— AjnxH-ao'-o'amx
aj aj a x o tn *— aj *— n aj in
mvo O' < o a a a m 3 mx
nn nnnnnxxxxx
<<<<<<<<<<<<
ooaaaaaooooo
Page 14
254
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
3
O
O
—‘ o *-«•-« X
12X«>*
« O O.
^ X o
• - .. •- as • -
X < < 3 Ci
. 'J x u. 3 E ;
) X H ■/) ix - :
) < O UHUli
J < X X a.
>< — OHOX3
) 2 'x O O x x ;
! X'J -OH L) < CQ • Q
)i->l*.HU.ZT -M -O
.UJhXHHUOl<l:
O -S x ■« to o z
:<UCQ^*3*-3 LUO
- a. X X -yj c 7) D X 'X t
Jjl7)xl JHU
o aa _j ox ■» —
r < x c/> x -
<t'jhx<oxc [ Ha
: « < x x .-« _
• X X 3 < rg :» «
) •»< y) o -a x c.
to _J X _J
• "I HNhOJHHWj:
>a.('ga.z<oo<»33< ;
.o-so-3_i_ixoxoa.c_>c
< X -I
:zi-i:4303XNa
e->yiTaxoa. oo-s_i
x ^ a. < < < < MH
-= f- T T as 3 as x >
~«-/)-axxy)_iO-3X
3 3 --3
<>j < >- -\J 3
O f^3J O O
X O O' u
o o o o o
x) n x Q x
0X30-3
X X n Q Q
3 0 0 0 3
'J^3 l AJ3'»-
> 3 3 o 3X o
J J < X o < o
)u.o3uioa
■> O X X O X CM
j 'X :u u x X X
J X X X X X X
>003033
X — o
3 3 3
=r — o o in
o 3 3 -» 3
x < < •j cm
X o c3 u. o
» -0 0*0 ij
X X X X X
X X X X X
0 0 3 0 0
> JO 7\ 0X0'
>03 33 — '
> o o o o o ;
>30 3 3 3:
>o — t— o — X
>0 3 0 O O O O
>-7\ rvj 3 o — cm r— -o 3 -Q
>3 3- no no CM O =T 3 AJ 3 3
ex CM < t— 3 X 3 3 3 — » X> O -M -M TO
> X O v >»onOQoOOO->-XonOO
>3 CM 3 O "T\ O X O — » 3 O t— O X
* CM CM MlMMCVIM-O-OcorOOnO-O-OO
>00 OOOOOOOOOOOOOO
>30 00000030 0 00000
O O — — X —— o
O 3030 030
x — <33 3 x 3 t— x x
< 0 3 3 3 -03 no 3 O 3
n 3 — 3 X < < o aj 3 xcm<mm o
X o X -5 X O no 3 "Ou < 3 3 33 O o
M'OO'^TNXX — 3) 3 330X33
»»»»»»»/> n ft 3 ia r* 3 o o
O O O O O O O ’3 O O O O O O O O
000 0 333000 300000
C v " C** N W H “
s or or X X a
M-ZCEzaviVia
O C3H O
to y> Z < 3 (O
tOih-ZOH
•a*W* *3 3
3 X —' O < O X X
C3 O X =T
x r 0 0 3
XXX X CO X
— X03X03X05
z ZMOr-a: • -a:
<<<XXO<OOX
> O as o
X < X
x XXX
.3X003=
> OHH O :
X O X X X U
: x xxx <—• • • x
:3X3X(3033-XCMXi->0
>OOX -33-/) 0X0X03
<Xt-iM<XZXc3‘-.OasXz<
-* X * J 3 _J -H
X<0<PM><X
JOXO-aXOO
M < < X —« H H _J f
zz<-.xzzngr»x<-
">XX-»*H<->XX03
X X X
—t XX<< X H NJH J
5XrsJZO<3Xr>lOXZ=»<l
-<<3-«XOX0-aXO3XO^
—1 I-. X X -H —( HM < < X X J X >-H rH >-i —<
J>OX3XMXiNlX-ZXf-*ZO<r>J<XfMXrMXn>lXr'
3X:0-aXO-aO->03XX -9X0-9 0 0-5030-30-
O O — 3 X -n 3 O 3 X 3Q
^030 003030 O O
-irv^aj 0M30»3\3n 3 AJ — 3 ^ — — 3
DOOCM 3 3 O » — DN3 — 3 3 3 AJ 3 O 3
U3XCMU.CMc33JO<X— 3 — 30<XJ<333
3 O X O < <3 o 3X0 3 — o AJOXO>-XOOAJO
euu. -? j)5oaau.i\j» n < 3oajx»o»oox
- — — AICMCMAJA4AJAJ-0 3 3 -3 3 :T Z =T :T =r :T Z
0X00X03000X00 X 30X00X000
3000000000030 O 333333333
o — a
O 0 0 3
3AIO- AJO n
0X0— AJO r\ 3 3<AJ3 — '—< — O J U, AJ CM ? O OAJ
O 3 3N O 3-3 -O 3-03rT03>-30T« -O - >3 3\ 3 3
3 O < O .3 3 <■— < — UAJX3-Q 0<X33 — X<X< J X X M3
3X0 3X0 300 XX 030 3 X O 3 3 O XX O X Ox O < 3 O
0<0x— M I'D JNO 3XAJ=Tn-3\OX0.AJr»O3033CM 30 T>
3 3 .3 30 3 O O 3 0 0 O'— r— C— *-Nt—0"0'C'0'OOJ53'3'7'J.>
oooo aaoooaooaooooooooooooooooo
0033300 03300 3 0 0300003303003330
OOO O O O O O
X — O-TXAJM — X 31 3 00 — 3
— 3 M — O — 0X33000X03
3 < 3X<U<X<X<X<3X
O O O X 0X0X0X0X03 X
OX M 3 C- < O X — -3- O 3V3J U 3
9>-7N<<<<<<Q3>aXOOO
D-anooonxoo.ooeQOja
33 0 333033300300
Number 26
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
255
DOUBLE-HEADED DRIVE FOR $755
* (-• 3
ox x
> H U. < O H
U U 3 - - -
Kunuiara<«
c/l
«* 5 'J <
r- to X
3<lODU
a. 3 je x
■3 _J QC 3
x aj x x
'jj w I f- r o
z r X *: x a:
<*: x o a: 3 *
x-o-o-
<c x: <c x o
oo oo
X O Q
-a ;
3 X C
Hi c/1 C/5 -A O
00 f— f— - -
x o o 3 x
■ “ f- MO X x ZUH
xxxo^xcc^oc^a
“5 _IXX_IOXXUO“
ljHMHHXXN*N<<N«<<Na,Q
><zz^x03*zoz3a=Z3aszxz
:u<nr jaxOTaT.JO-jjDnu
C/l X
I o
I f-
c_>
o
O'
<
rn
o
-- o
3 3
3 3 3 <
"O 3 X> —
< X -O i— ET' -U
(O f\ ■- fM •- ri
O' n a
3 3 3
a o •-
3 -O^
3 3 a
0 3 0
<A o
3 3
«- aj x <A ct\ *- LA
30300^0
uj ro lij ro y r- a
A 3 A 3 3 O
aj o aj a
ros? O
3 3 AJ O
O'jIO I-
X 3
X 3
X X
X ?
*- a xi «- "vi n
3 3 t- a o —
3«- r* —
3 3 O O
o -a: «a
x -a
•AJ «< --aj < f- AJ A
o axo -a 3 oo
c o\
3 3
*<
O' O X 3 AJ A O O Tl'J X
*” »- >- AJ AJ AJ AJ AJ AJ AJ AJ
3 3333333333
3 0330330333
AJ 3- sO A5 < O X
•n "O-O ro-o'O-o
3 3 3 3 3 3 3
0333330
AJJA C O X 3*-AJ -A OJ\oa3fO»t'4
=r =r a- a a a a a a a a o
3333333333333333333
0330303333333300030
News Release Received: 78 May 10
Pertec Computer Corporation’s Pertec Division announces
the FD650, a standard-sized (8-inch), double-headed flexible
disk drive capable of recording and reading data on both sides
of an IBM (or equivalent) Diskette 2 or 2D. The new drive also
features double density recording to offer an immediately
addressable unformatted storage capacity of 1.6 Megabytes.
The FD650 is media compatible with IBM Diskettes 2 and 2D
and electronically compatible with the current proposed
ANSI standard. It will be incorporated into several MITS/
Altair and iCOM systems manufactured and marketed by
Pertec Computer Corporation’s Microsystems Division.
The new two-sided diskette drive is capable of double-
density operation using MFM encoding. Each drive is equipped
with a door lock, and the drive has die-cast construction. All
electronics are on a single printed circuit board. Track-to-
track access time is 3 msec. The user can daisy chain up to
eight drives. Head positioning is achieved by a steel band
attached to the head carriage and to a drive pulley on the shaft
of a four-phase 1.8° permanent magnet stepper motor. Each
step of the motor causes the head to move one track.
The FD650 is priced at $755 is single quantities. OEM
quantity discounts are available. Contact PCC, Pertec Division,
9600 Irondale Avenue, Chatsworth, CA 91311; (213) 822-
9222, Neil McElwee.
GO X 3 00 00
= CO
H Z
X —I
X 3
X
3
X X
= f-
x O
3 X
. O - X
< U C/l CO
1 XXX
> X X f— X
O X O -Z
X t— •— X as ♦ X
>-.(-• X f-- 3 t— X X X ♦ X CQ x
<t >< U << < Z < X 3 >1 X X + X CJ oo X
ai na ju ♦ o x o x
XX 71 X X •/) Q X 3 MX - XXX* t - - 3 <
OMXOMHE'SMrXHXXMMOH ♦ U3XX«
3 O
: x — x
• <_> 3 X
.astOcOf-
. -% X 3 3
) - “3 <
1 U Q X X
3 X H-
O 3 D e
X .X o c.
; 3 E- X 3
-33X3
) X X X X
> X c
u :
X X 3
> f— 'X
< 3 X a
: x x t
- * x ~
> 71 O Cl
: x H c
XXX«*XXX'X1*Q
: 7) 3 COM -TlOTlMX
» 3 X •- X 3 :» ICO X
3 O X X -3 U M 3
xxHx«:xxxQ^a3
xx x xxm >-< e>j *-< x ->j a* _
*<xx-<r>ix<zcgz:x-s^3zx-
33X33 - 33s<3'-»33X3 3-aC,
>»-l3-93-33-93 - >3-»X3X
XX X X X X
a,_ja_xoOxa-I—<oOxxx-<^«
a -'»“’-»:x3X33:X3XcjXD
50 X
x xe-xxx«*:«<
NszN>Dl < X H
3--—
■» X 3 X CO
t- 3 ^ 3 3 3 3 3 3 A-3
33 3333 3 3 33 3 3
<3 X =T O AJ AJ X ■— 033 /I Q 3»-
33 -->COnO OOOOAJ O 3 O A
3 'A o<-ootKadAio Atroq-o
3 0 3 3 3 3 'X O 3 X 3 3 3 o 3 3 3
3 3 3
3 0 3
AA O JA O
•- JA O 3
x — a 3
3 •- 3 3
*- =r o
3 3 3
O O' X JA
3 3 3 3
AJ X *- 3
3 O •“ O
3 AJ A
3 3 3
X O AJ
3X3
3 3 3 3 3
*-«tO 3 3 <- O =Z
3 «S X 3 X < 3 3
0330X333
0 3 3
3 3 3
f— 1 A O 3 X
O •- X 3 •- 3 X
X X < 'X < 'X <
3 x O X O X O
U,3'Oq»
A1 <«
X X < A
X 3 X 3 X
c— x> o
o o o
AJ <*, O'
=r x <
3--33
3X33
AJ C ■X AJ
X 3 =r
A 3 — 3 X A3'
X 3 X 3 3X0!
-O'- 3 3 3
3 3 3 3 O
<3 a i- < r- cr.
X 3 «C33333<
3<A-<X3«ZX33
33X33X3^33
A X J]J -- J n- AU J 3 3 A OCAOX
OO O O — OO X) O O C O
33 333333333333333
33 OOOOOOOODOOOOOO
AJ ? N O d i- 3 O
J'7'7'0'5 \ON<j:C<
333333333
333333333
3>XO 0 3002
XXXXX
333 33333
033 33333
3 3 AJ A — O' 3 X «—
X 3 3 333333
333 333333
333 333333
AO-OBOOr-J'ATJ
3 3 3 3 3 X X X X X
3333333333
0333033333
XOX3'AAOON«<30 — ^-3XX3X AJAX
X X X X X X X X X X 3 3 O 3 3 O O O r—r—T—
333333303333333333 333
333333303033333303 030
Page 16
256
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
AUTODUMP: A MEMORY DUMPER
FOR POLY88 TAPE SYSTEM
BY RICHARD B. EMERSON
158 E. Butler Ave.
Ambler, PA 19002
© 1978
There comes a point in every programmer’s life when it
seems to be a good idea to store the contents of memory on a
permanent medium like tape. This usually comes about two
seconds after said programmer realizes that a particularly
brilliant piece of code has just been clobbered by a stray glitch
in memory. By then it is too late, but for those who plan
ahead there is hope and AUTODUMP. This program of 1047
bytes will dump the contents of a POLY88 onto tape in either
BYTE or POLYPHASE mode. That, in itself is not much, but
AUTODUMP will also write a banner or comment record
block of 255 characters and automatic execution of a program
dumped by AUTODUMP. If you are sufficiently impressed
with your handiwork, you can command AUTODUMP to
produce up to 255 copies of that file. All. that is required of
your system is that the POLY88 USART kit be installed on
the CPU card. There are three monitor subroutine references
and four memory references related to the monitor. Each one
will be explained in the following paragraphs.
The accompanying source listing has arbitrarily assembled
to begin at 6000H but there is no limitation on where it can
begin. The absolute references are all outside of the program
and the various constants do not take advantage of page
boundaries or any similar technique. The data area at the start
is preceded by a “JMP” only to make sure that the data is not
accidentally erased. The actual program starts at the label
ENTER. If you wish to load AUTODUMP first and examine
its workings later, be sure you read the following paragraph!
There are some very interesting features in the program and it
would be a shame to miss them.
Operation
As stated above, AUTODUMP will dump files in either
BYTE or POLYPHASE mode. On beginning execution, the
first message is:
TAPE MODE:
Type either P or B depending on the desired mode. Do not
forget to connect the correct output lead to your tape record¬
er as this is CRUCIAL! With the mode selected the next
message will be:
TAPE NAME:
Type in the file name that you want. All characters are legal
except <RUBOUT> (A note about notation: <CHAR>
denotes an ASCII symbol. Resist the urge to type the eight
characters mentioned above to clear a letter.) It is suggested
that names be limited to alpha-numeric characters. If a wrong
character is typed in, typing <RUBOUT> will not appear in
the file name as it does with some POLY88 routines. With the
name loaded the next message will be:
START ADDR:
AUTODUMP is asking for a hex address that marks the
start of the area to be dumped. Typing any character other
than 0 through 9, A through F, or a carriage return, <CR>,
will cause the question to be repeated. If you realize that the
address typed was wrong, typing any invalid character will re¬
start the request in progress. This rule applied to all hexadeci¬
mal entries in AUTODUMP. With the starting address loaded
the next question will be:
END ADDR:
The address that marks the end of the dump area has been
requested. It is suggested that, if the area ends at FF42, that
the entry should be FF43. As you will see from the code, the
area need not be on a page boundary. With the dump area de¬
fined, AUTODUMP will now want to know where the data is
to go upon reloading. This address is requested with the mes¬
sage:
LOAD ADDR:
The address may be the same as the address for START
ADDR or it may be completely different. Bear in mind, how¬
ever, that AUTODUMP does not perform code relocation but
merely tells the tape loader routines where the data is to be
loaded. If you assemble a program at 8800H and reload it at
2000H, it will not run unless the address references were based
on 2000H. The final address requested is the place where pro¬
gram execution is to begin and the message is:
EXEC ADDR:
This address may be any address in your system, it does not
have to be within the dumped file. Thus you could load data
and then go execute a program that will munch on the data or
you can execute the data that has been loaded. Naturally it is
also possible to begin execution anywhere in the dumped area.
If you do not want the file to auto-execute, enter any address
or type <CR>. Omitting the banner record will keep the file
from causing automatic execution. With the execution address
entered, the next question will be:
NO. COPIES
IN HEX:
Page 18
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Number 26
Type any valid hex number and you will get that many
copies of the dump, each with the banner or comment that
will be typed in, each will start at the same place, and each will
end at the same place. No additional type-ins will be needed
save that of starting the next copy. The banner or comment re¬
cord serves two purposes, first it allows a file to identify itself
and second, it serves as a flag for auto-execution. If there are
no characters in the banner table, at the end of the dump the
file is closed without an auto-execute record block. The ban¬
ner is requested with:
COMMENT CCTRL/D TO END>:
Avoid typing in control <CTRL/*> characters as they can
confuse the POLY88. <RUBOUT> erases characters but
each <RUBOUT> counts as a character so it is better to erase
the banner when more than one <RUBOUT> is needed.
Typing <CTRL/X> will clear the banner table and also clear
the screen. If your keyboard cannot produce lower case let¬
ters, don’t despair. AUTODUMP looks for a character that is
reserved as the “flip” character. This character tells the banner
routine to flip from UPPER CASE to lower case. Note, how¬
ever, that you must “flip” back to upper case before typing
<CR> or <RUBOUT>. Clearing the screen with
<CTRL/X> also resets the “flip” flag. You may flip from one
mode to the other as often as you wish; use of the “flip” char¬
acter does not take up banner space. When the banner is typed
in, type <CTRL/D> and you will get:
READY TAPE, AND PRESS ANY LETTER:
AUTODUMP starts dumping only when you give it the go-
ahead. It does not start before the banner is finished unless
you have typed more than 255 characters. If you find AUTO¬
DUMP has begun before you are ready, press RESET on the
POLY88 and then <CTRL/Z> to enter the front panel mode.
From there just type <SP Jaddr> where addr is the starting
address for AUTODUMP. You will have to re-enter the ad¬
dresses and so on, but at least you won’t be waiting for 10K of
core to dump out in BYTE mode! It is possible to dump dif¬
ferent files without reloading or restarting AUTODUMP. When
the last copy of the current file has been written out and its
execution address listed, AUTODUMP will clear itself and say:
TAPE MODE:
This is where you came in. If you want to, go play with
AUTODUMP and then come back to see how it works.
Description
In effect AUTODUMP is an oversized “block move” com¬
mand except that the receiving area of the move is a tape and
not a location in the memory of the POLY88. Additionally
provisions are made for breaking the transfer up into 256 byte
blocks to allow restarting a file in the middle of a read. The
USART is driven much the way that it is in BPRINT, PolyMor-
phic’s printer driver for BASIC, except that there is no large
buffer. The USART generates an interrupt and AUTODUMP
makes sure that data is ready when the USART asks for it.
The monitor references appear at the beginning of the list¬
ing. SETUP is a routine that initializes the USART with the
data that follows “CALL SETUP”. Notice how the manipula¬
tion of the stack saves much time and confusion. HEXC is a
routine that accepts hex characters 0 through F and converts
them to a hex address that is put in the HL register. B contains
the number of characters in HL. If there are less than four
characters the leftmost bits are set to zeroes.
Any non -hex character causes a return from HEXC and the
last four valid characters are in HL. DEOUT outputs the con¬
tents of the DE register as a two byte hex address. TBUFF is
a two byte area that holds a status flag and data for the
USART when it is in the tape mode. SRA4 is part of the inter¬
rupt vector table and it points to a routine that will service the
interrupting device. WormHole 0 is the keyboard driver and
puts data from the keyboard into the A register. WormHole 1
is the entry to the CRT driver and puts the contents of the A
register onto the CRT.
The data area of AUTODUMP consists of two areas, the
record header text and scratch space including the banner
table. The order of the header area must not be modified or
the POLY88 monitor will not be able to read the tape. This is
because the data stored here is copied directly by use of the
HL register. The scratch space is not restricted and may be
placed anywhere that has enough space. The jump over the
data area helps to define the data space and is there for psy¬
chological reasons more than anything else. If you need the
three bytes, take it out and start execution at ENTER’s
address.
ENTER puts the address of TISRinto the Interrupt Service
Routine Address table so that when the USART causes an
interrupt the CPU will know where to go. After TISR is set up
the screen is cleared and the mode request is displayed. SHOW
is a simple routine that takes data from a table and ships it to
the CRT via WH1. This wormhole takes the contents of the A
register and puts it into the memory dedicated to the display.
This process will continue until a 00 byte is seen. There is no
limit on the string’s length or content except that the string
will end with a zero byte. The string is selected by putting the
proper address in the HL register. WHO is used to get the type-
in and that character is returned in the A register. Bad data is
ignored and good data is displayed or “echoed”.
With the mode selected, SETUP is called. This routine takes
the bytes that follow the call and outputs them into the
USART command register. SETUP pops the contents of the
stack into the HL register. Since this is the address of the call
plus two bytes, HL now points at the first byte after the
operand of the call. If “CALL SETUP” is at address 6000,
starting at that address memory will look like this:
C3 AD 02 05
When the call is executed the stack will contain 6003 which
is the first byte after SETUP’S address. If “POP H” is executed
HL will contain 6003 and a “MOV A,M” will put 05 into the
A register. The question is then how to get back to where the
“CALL” originated. As SETUP goes along it keeps sending out
data and increasing HL by one until it hits a zero byte. This is
the signal that there is no more data. All that is left is to put
the HL register into the program counter with a “PCHL” in¬
struction and the program comes back to the byte after the
last byte of data! Thank some unknown wizard at PolyMor-
phic for writing that gem.
Even though the USART had data put into it, it still will
not run and it is just as well because there is still more work to
be done. The file must have a name and a size. The name is a
fairly straight-forward process. The area where it is to go is set
to spaces and then data is filled in, letter by letter. It is
Number 26
258
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
RUBOUT’s job to back up over any character that is to be
erased but not to go past the start of FILENM. When there is
no room for more letters or when a <CR> is typed the file
name is complete and the starting addrsss is requested.
All addresses are brought in by HEXC, a monitor subrou¬
tine that puts a valid address in the HL register, the number of
digits typed in are in the C register and the last character seen
is in the B register. HEXC also displays the data as it comes in.
A check is made in AUTODUMP to make sure that HEXC
ended with a <CR>. Anything else is invalid and the address is
requested again. This allows errors to be corrected without re¬
starting AUTODUMP. Once the starting and ending addresses
have been entered the length of the file is computed by sub¬
tracting the ending address from the starting address. This
takes place shortly after GETEND and the start of the subtrac¬
tion is “MOV A,L”. Ordinarily the carry flag would have to be
cleared before the subtraction can start but the “JNZ
GETEND” instruction insures that the carry flag is cleared to
zero. The program can only transfer here when CPI ODH sets
the zero flag and at the same time clears the carry flag. This
may seem a trivial thing but it is important to know that this
little trick saves two bytes of code. It would otherwise take
“STC” (SeT Carry) and “CMC” (CoMpliment Carry) com¬
mands to clear the carry flag. With the subtraction completed
the length of the file is set. By figuring the length it is possible
to test for the end of the dump without having to test two
address bytes. When FILESZ is less than 100H the last block
has been written and the dump is over.
After all of the file size data has been collected the load
point and execution address are requested, then it’s time to de¬
cide how many copies are to be made. Each item is a simple
type-in and their values are not really used until the file is re¬
loaded. For that reason discussion about them will be delayed
until the tape writing begins. What remains, then, is the ban¬
ner. If a simple <CR> is typed in, a one byte long banner is
created and the whole matter is ignored. On the other hand,
if data is typed in, it will be displayed when the file is re¬
loaded. Remember that short files read in with POLYPHASE
do not take long to load and the banner may not be displayed
for long.
Each byte typed in belongs to one of three classes. The
most common class is a simple display character. It is placed in
the table after being ORed with the B register. If B has a 20H
in it, the character becomes a lower case letter, otherwise it
remains as it was. The next possible class is the “flip” charac¬
ter and it may be any character you wish, excluding CTRL
characters. Its function is to change B from 00H to 20H or
vice versa and this “flips” letters from upper to lower case.
Because the “flip” character is not stored, it is possible to
“flip” as often as one wishes. Note, however, that some char¬
acters like <CR> do not survive being “flipped”. The final
item that may be entered is <CTRL/X>. This is the character
that causes the screen and banner table to be cleared and
allows new data to be entered. This does not clear the ad¬
dresses or number of copies counter. It does mean that 255
characters are again free and that all old data was removed.
The <CTRL/X> is the best way to correct the banner because
<RUBOUT> does not remove data, it only covers it up and
takes up banner space as well.
With the banner loaded the program waits for a type-in
that indicates the tape is ready. This allows time to change
cassettes and check the recorder. On receiving the type-in the
size of the banner is checked. If it is one byte long the pro¬
gram goes on to dump data; if not, the banner is dumped to
tape. The dump procedure is similar for the banner and data
records. Each record contains 16 <SYNC> characters, a
<SOH> (Start Of Header), the file’s name, the number of
bytes in the data area, two zero bytes if the record is a com¬
ment otherwise the starting address for loading the data, 01
for a comment or 00 for a core image, the checksum for the
header, the data or banner, and the data’s checksum.
The program transfers to DUMP and it displays the address
being dumped out. The inter-record gap is generated by GAP
while SYNC outputs the <SYNC>’s. These characters are used
to ensure that the USART knows how fast the data is moving
so that the USART can either say it “knows” what the data
rate is or that something is wrong. Notice that there is no
“OUT” instruction in SYNC, the data is actually sent out by a
call to TAPOT. We will discuss it after the header has been de¬
scribed. After completing SYNC, a <SOH> is sent to indicate
that the data that follows is the header proper. The A register
is given the number of characters to be output from the header
and HL is set to point at the beginning of the header data,
FILENM. Since the header will be concluded with a check¬
sum, CHKSM1 is called. Notice that all of the data for the
header is grouped together in the constant area at the be¬
ginning of the program.
Checksumming allows the verification of data and, al¬
though far from perfect, gives some measure of assurance that
what is received is what was sent. The method used here is
based on modulus 256 arithmetic. The data ranges from 00 to
FF (0 to 255) and if each byte is added to the sum of all the
previous bytes we have the basis of the checksum. Naturally
the sum will go back to zero if 1 is added to FF, but for the
present scheme that is acceptable. When the last item has been
processed, the l’s complement is found and 1 added to that to
give the 2’s complement of the checksum. To verify that all
has gone well, take the sum of the data and add the check¬
sum to the summed data. The correct answer is zero and
anything else is a sign that something is wrong. Look at
CHKSM1 and CHKSM2 and you will see the steps described
above. Keep in mind that the C register keeps track of the
number of bytes yet to be written. When C finally equals zero,
program flow falls through to do the complement and on to
TAPOT which writes the checksum onto the tape.
TAPOT saves HL, looks at TBUFF, and saves PSW. TBUFF
is a two byte area that holds a status byte and a data byte.
When TISR services the USART, it will set TBUFF to zero in¬
dicating that putting data into TBUFF+1 will not damage any
existing data. The three instructions “TAPOT 1 MOV
A,M/ORA A/JNZ TAPOT 1” may seem to be a closed loop
but HL is pointing at TBUFF. TISR can put a zero into
TBUFF so it is possible to exit the loop. At this point there
are probably readers who are trying to figure out how the
program gets to TISR. Up at the very beginning of AUTO¬
DUMP, at label ENTER, the address for TISR was stored in
SRA4. When the USART generates an interrupt, the CPU will
“CALL” the address at SRA4 effectively calling TISR.
TISR clears TBUFF and then puts TBUFF+1 into A. With
the data in A, an “OUT 0” sends the data off to the USART
and the tape. The stack is restored and control returns to
where the CPU was when it saw the interrupt. With TBUFF set
Page 20
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
259
to zero, the data is loaded into TBUFF+1, TBUFF is set to
one, the data pointer is restored to HL, and control is returned
from TAPOT.
With the header written out, the data itself must be
dumped out to tape. The process is controlled by DMPFULL
and DMPPART. A check of the data block’s length is made. If
the block is 100 hex bytes long, DMPFULL causes the bytes
to be output along with a checksum. This process continues
until the size of the remaining data is under 100 hex bytes. At
that time there is a “JMP” to DMPPART. Notice that the pro¬
gram falls directly through from DMPPART to TAPOT1. At
the end of TAPOT1 the “RET” causes a return to the “MVI
A,2” after the “CALL” to DMPFULL. Here the banner size
is checked. A one byte banner causes a simple end of file re¬
cord to be written. A longer banner causes the execution ad¬
dress to be put into an Auto-Execute record. If the number of
copies requested is zero the program goes back to ENTER. If
not, the counters are reset to their values at the start of the
dump and the program goes to NXTCPY.
That’s all there is to AUTODUMP. It is a program that
scans memory in 255 byte chunks which can be passed to
tape. Now that you know how the files are written, why not
try to write files in other formats? Since you know how the
files are constructed it should be easier to write a program to
read those files. There is no reason why your POLY88 can’t
read other tape formats.
MICROSOFT’S COBOL-80
News Release Received: 78 April 13
Microsoft is the first COBOL for 8080/Z-80/8085 micro¬
processor systems. COBOL-80 conforms to the 1974 ANSI
standard, thus giving users immediate access to programs
already written in COBOL. All Level 1 features and the most
useful Level 2 options for the “Nucleus” and for Sequential,
Relative and Indexed file handling facilities are included.
Additionally, Level 1 Table Handling, Library and Inter-
Program Communication facilities are provided. Of the
advanced Level 2 features, Microsoft has included the verbs
STRING, UNSTRING, COMPUTE, SEARCH and PERFORM
(varying/until), along with condition specification by way of
condition-names, compound conditions and abbreviated
conditions. COBOL-80 allows a packed decimal data represen¬
tation to conserve memory on floppy disks.
The COBOL-80 system consists of two packages: a com¬
piler for translating source code into relocatable object code,
and a runtime system containing standard routines needed by
the object code at execution time. The whole system may be
run in less than 32K bytes. Rate of compilation is 250 lines
per minute. Complete documentation is supplied with the
system or may be purchased separately for $20. COBOL-80
is available off the shelf to run under the CP/M and ISIS-11
operating systems for $750 per copy. Microsoft, 300 San
Mateo, NE, Suite 819, Albuquerque, NM 87108; (505) 262-
1486.
z
UJ
X
z
u
z
l-l
X
X
X X
UJ
CL
uJ X
X
CO
~l
J X UJ
z
M
Pi
LL
z
P
- X _!
X
UJ
z
UJ ^
UJ UJ
UJ Z
co a. m h
LU
LL
I
X
UJ
_J ©
A CO
© E-
-J LL
UJ
x
X
£
(J
Pi UJ
UJ Cl
© uJ
□ ..
□ Z
X U i-i
J
n
CO
~i
z y-
lL X
CO ©
Z uJ
X ©
a □ u a
*—•
UJ u lO
Pi
LL •—
lU X-
CO UJ
►— LL
CL E- X
Ul
y—
□
LL
UJ UJ LL
r-t
I Pi
ul Cl
UJ Cl
LL A U *-•
•z
LL
U LL \
X UJ
X LL
ll X
□
Z X
_l
E- Zt
x a j; z
□ CO
o
Ll
UJliMHiL
X Pi
LU
U 3
X U Pi
LL
ll Cl
UJ
□ ®
> E-
Cl u! ul CJ Z'
E- CL
□
_' l-l
ll
lL
l—
i- a □ z
© ©
co a
_l
X
Cl *
© UJ
uJ CJ Ul Z ZE-
Z
-1
Pi Z Pi □
□
UJ
Z LD
z
UJ
LL
©
X
CO
© Z □ E- © X
UJ CO X CL
UJ
LL LL
X
Pi
u. y-
I
Pi
LL X
LU 1- CO
UJ
U'
□ v
•I
z
Cl ' £i
CL ...
X « E- > > UJ
X e- CJ z
LL
Z Z
«5 uJ >■ y—
□
Z
(J —'
XhD CO X
LL ©
M
1—
in
□ Ul
□
X> © E- Cl E-
Z X Al
co x
•I
X UJ LL
UJ
CO
LL
•>> UJ
X X UJ '_'
UJ
X I
Z
Ll o
LL
Xr J X e-
X l-l CO E- CJ
sit
—• (J
CO P O
1- _J
►—
LL
Pi
□ uj uJ LL i-
© a
LL
E- Ul
UJ
X X Z Zt UJ
□ 3
CO X
Zt y-
LL •—
•—<
UJ X
CO
X X Pi Z
Z y-
UJ
r-t
X UJ UJ ©
>
E- I
X E-
A3 □ ZZUJCLd □ E-
z
i — Zt • *■
Z u
u
Pi <J
CO LU
X UJ Pi ll
a
CO
LL 3
uj © co a
CL
LL •■£>
Z CL
Cl □ e X u UJ Z
J E- Pi -1
A.
□
UJ LU
Pi
z □ •=• —
y—
X E-
Ul LL
CL □ Z (J
_J C)
LU
CO
E- □ X X
Z aJ
X Z o
□ u UJ - XX
•- _l 3 □ CL
N I
y- ll
CO U.
.. LU
X' z
LL >•
□ X CO
UJ
y—
•-« E-
x □
CO —'
(J W ♦ E
U. X u CL CL
CJ
E-
CO CO UJ LU
□
2- X
X LL
Pi h-
Ll '£' ID
z* y—
LL
Cl
i- Cl
□ LL UJ
..
Cl X' »
UJ Cl X> I
J UJ □ A □
.»• 3 CL Z V ©
cj
_J CO
>
LU _l _J
CO
u z
l_jl
Pi
LL LL X (-0
x > a
Z
O
y- h* co e-
Cl
\ X
CL \ UJ
I Cl E Cl ^ © E-
E- Z X 3
II
LU
z E-
z
i- □ O
UJ X
¥—i x
Pi CO
Z Pi
Cl O -• CO
*—• ©
Ll
CO
l-
C O Ul >
>-• LL O
■I H LL
CO 1
CO E- X CJ II CL
LL
— LL
—1 ' I I
X t—
Pi
Cl
Cl
UJ X f- UJ
r—
ll Cl
t— Ul LL ©
Cl y- v _J *h v y-
UJ LL CJ
LL
r- UJ Cl
LL > X X
l£l
D Ul □ Ul
Pi □
LL UJ LL LL
LL U
u
Ul z
□ ” ”
a ”
Z UJ X 1 CJ X
3 Ul □ CL *•
CL
□
*-« i_i
vt
1- LL LL LL
U X
X _J
N
Z u
U r-J Z* Z Pi
•I □ □
1—
CO UJ
HGE e-
©
X E- I
k x y- i
UJ CO UJ t— II •_> e-i
•3 CJ E X Z ' 0
X
•J
X •_<
I—I
Zt u □ o
UJ UJ
LU -•
a UJ
X' — UJ y- Pi
►—
UJ
X _J
□ Ul UJ UJ
•I
UJ ■=•
UJ (J UJ ©
_l UJ CO 3 _l II U □ UJ u Ul U I UJ
X
Pi
□ CO 3 3
Pi _l
I- Ll
LL CO
-J Cl
Pi CO Pi '. 0 Z
co t:
j;
l£|
*-• '_'
CL CL Zi CO
©
UJ CO 't
Z' UJ CO
J Cl X' f -- CL I u H Cl LL Z Z> UJ O >
CJ
E-
•»
□ ...
...
...
...
_'
X
z
X
X
X
X
Cl (O
LU
I-
z
•I
X E-
Z LU
X X
□
Cl
a.
X
•I
z
X Ul CL X
UJ E-
m ij
I
X X X X
LL
Pi
Z
CO
I
E-
q
a. o
X Cl ©
3 X J I -1 E-
_J 3
Z
Pi Z
«■*
CO X o •T
UJ
X
’t '_'
© 3 UJ
X
X X' »
X CO 1- © U X
3 — a
X UJ
Z Z
Pi
■=• — CU OJ
I-
1
y—
©
1-
•I o
-h X □ © E-
N E-
hET
E he I
© CJ © IL 0J XX
□ u co © - I ©
X
h- LL
OJ CO
CO
O
X
X
©
LL e.
I - I I « >
Cl UJ X uJ If'
LU I UJ •■£'
,. Ul • » « z *
I e. . I I U 3
A
—• LU
©■ ©
®
® ® o ©
UJ cu
Z 00 cu —
CU -H
UJ
— ^ 0J cu cu
cu cu
T-t
I CO z
3 X CO 3 • ©
\ in
3 (,/i c
III 3 CO ©
X CL CJ X X X (J X X
CO X CJ 3 3 N CL
©
3 Ll
LU
UJ
LL
y-
t LL
Z
CL
CU LL
►—
LU
L-l
©
_l _J _J
_l -J
-J -J
A
_l _J -I
> □
Xi 3
X<
Zt X' Zt Zt
Cl
X
z
_l r-< _l _l »-«
N _l _l
Cl _J _J
hJhmhXClN'1
_J i-i i-i _J _J •—
i—'
E-
G c;
U O li G 0
X CO
UJ CO
CO CO
CO CO
UJ i/t 1,0 CO ', ' '
co co
i/t
X I >
Z X Z Z Cl f J Cl X
•I Z ©
X Z Z ©
X X > X > CJ O X X Z X > 'I LL CL r J
Cl
X £
UJ UJ
Ul LU UJ UJ UJ
J Pi
E- Pi Pi Pi
Pi Pi
X
© © © Pi ©
© © ©
_J CO X
U JOOOI
O “)
O CJ A
-i O O A
J CO X J X © © -} J CJ J x Lt CJ O
CJ
3 5
LL
u.
Pi X
M
UJ X
ll ll
□
_J © © CL
Li LL □
CL
□
LL
e-
Ll
1- CO
Pi X
X' N >
© N © © >_•
©
Cl
A
X J
X
1— ©
—1 (J
X
Ll *t
LL LU
Z UJ
X co co y-
Pi
y- n/t z z co
Z CO
Ul
X
UJ
X u
X
•
E- X
□
X* z ® —
Z _J
LU _J
M
7~
LL LL l _l LL L-l
© X
LL
►—
E-
y-
E- X
y-
z
UJ UJ
UJ
Pi Cl X I
I- •-•
X —
LU _l
a uj
UJ
X X X y— Ul
□ uj a
Ul
5-
UJ Z
UJ
" ”
CO X
Pi
y- (/> 3 3
». C O Ll
... u.
LL Pi
_J CL
...
© © UJ CO z
_i _i
o
.. uj
z>
©
l£i 2
ID
A Z ^ CO Z> O t
z z © o ^ cu cu
>\j co ' v > i_> i_j i_i o
'■£'
u
!_j lli
®
0J O 0*1 CO OJ © O «-< I_I OJ ©
•£' © O v£l *.£i © -£l •.£• rf- •£> rf
•V -it CJ U CO •=• CO © © ■=• *T X •£■ CO © X
U — O oj ‘it •£' OJ rt \r, CO OJ X 'X UJ If' Oj -r 'X
«-• OJ UJ A «-i A A UJ 'I LU OJ A © If' *•£' l v i m A •£'
OJ CU CO (j OJ CJ CJ U CJ Ll. CJ © lu Q i_'i ©
•=• o ©
© '.£| -.£)
© 1=1 CO
o o o o
*-< OJ LU
0J OJ © OJ
CO
‘■it
CO CO © LjO CO
X> ‘it ‘ it '£' © © ■.£'
CO Pi CO If.' 'X' © "t U Ll ©
•XI r - • £' © © OJ CU N *T o
©acu^©-hujaaujxuj
OJ © O CU OJ © O O U O' li.
© 'l‘ !f' Pi u.
‘■St ' it 'it 'it ' it
•XI
'■it
U- OJ If! l- 'X Pi O CO l it CO 'X Pi © CO N •! © © CO f •- CO Pi LU O CO Ifi 'it N 'I Pi CO IO 00 A A ©
—• oj oj cu oj cu co co co co co co -r rt xt ifi 10 in to to in ■.£■ -xi -it x« x> x« x» r- n nnn r- co
'■it X' X' X' X' Xi X' ' it X' X' X' X' • £' X' X' ••£' X' X' X' X' X' •■£' X' X' X X' X' '-it X' X' 'it X' X' X' X' X* X' • £' X' X X X X X X
Number 26
260
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
CL
a. u)
x z
i □
“* uJ i
lit ►
□ .
uJ
Z Q.
Z UJ
□ Z
'£• □ a.
x j.r i
_J UJ X '!
x lit i— :
□ X
UJ E uJ UJ
X X
•_> *X
J 1=1 -I
i X 4-
■ UJ
lit > X
M LL UJ
: □ x x x •.
>UJIZ.
X
1=1 UJ X'
N X
J ~ X Z
: " 3
: co o»
I □ M w it J
i □ :
1 11 LL X Z L
Cl
k- ►
a •.
X uJ
I
□ a
• x UJ
11— i=i
X D
Ltlhll Z X
X X* Z X 1=1
uJ ■_>
co lit
a
UJ X' X* Ul UJ Z UJ □ X'
t- i=i UJ UJ Cl UJ X
x- x jijoi
... .x* 4- —
O *-< X
UJ
:> h-
X UJ
>
z
1=1
□
X
I
lit
O
X
CO
O
4—
•=•
X
X
X
N
X
4-
a
>-<
O
>
>■
a
r—
CO
®
X 1=4
1=1
X
N
jL
Cl X
If .'
lit
=4
O'
a a
'j-
co ir>
X
X
X
•X
X
•:u
4-
□
1=1
X
X
X
X
0 1
lit
X >»
N
□ 4-
a
4-
X
X 1=1
•—1
X X Lt
LL
X
1=1
X
CO
4=1 1=1 X
X
z
>-<
X
f—
X
z
III I
= 4-
X x X
4-
X
X
•=• X
— a —
X
X
«-« 4-
X
a
1=1
Cl X
X x Ct
r
lit
Z »£■
X X
O O'
a
_i
N Lt
■=• □ X
X
• r.
CJ
4=4
— O
As X 4—
X
X
CO X
** Cm X
z
lit
K
M
v 1=1
X
'HZh
D j UJ
illMill'
f J
lit M A I (
x r© □ . •=•
« J X CU i
: x x z z x i
> Lt 4
' X I- 4
I Lt I .' 0
« X X Ul J X Cm 1=1 x Z Ul J I
I i—i lit I- CL •=• Z > UJ
• = u Cl (j •=• X' 0. _l
i x ' 1 x co •=■ z. u •-«
I M W Ul M l J h It E
' □ □ • w . Ul X • *
.JJIIIitZIX
ui to
O' i=i
CO □
x q z x M a x x x x z >=•
- — ••• *- a - - — — 11 x-J■ ‘0 e z i/) x co z v) _j >_i i x •..••.i _i I.i x co o< i»—< » _i (I _j >: i _j co _j co j x □ i a x co o Jmm jh- —,
x
□
CU •:
• UJ f -
■ UJ *t
—* *r '
•‘•J CU >'
.-.j ,-.j .■
J •=■ •
> r - Q co <_■ i'u •
'» r- oj •=•,
i ■=• «-• oj u' •£■ r--
< - u. — oj •
• -ill o •=• — .
J X OJ UJ OJ i
I OJ 0'<
I OJ OJ I
I 'XI •£. '
X I
OJ Cu •
■ ’t ’f "t rt
I OJ OJ OJ OJ
> •£• •■£• '£' •£•
UJ -« *T •£• '
t If' If' If' l
•‘•J OJ OJ OJ >
=•*-'*-' OJ *-« OJ *-• O O i'O •-< «-• <-« O <-• O »-« O O CU •=• CU O CO r-t *-> o
Jl> •£' •£' ••£* ’ ll' ■£■ •■£> •■£• •£' ■£' •£• •£' •£' •£■ ■•£' •£' •■£> •£' •£• •£' •=• •■£> •£• •£• X* <£i ■ £' • £■ ••£' •£>
2 2 ^g jj 2s§J8222Sfe2 2 2£22222S°g * x*<* oj^
•J X CU 1=1 UJ OJ X UJ X UJ -‘'J X OJ UJ OJ 1= — IT- X X OJ X OJ — OJ — CU CO ^ UJ i y'l Lt i'O Cl I ^ CU ^ 1
o '.'J CU 'X' CO CO CO X O CO* CO OJ 0J CO CO O CU CO O OJ CU CU CU CU OJ CU OJ (J CU f - <£t CJ CO X CO o CU CU CU CU 0
ti rt r. x >_■ u. oj t r . ij. i_i u. -'u *t r - x i= uj —■ t r. x i= •=• co •£« <j> >_■ u. ■=■'-< ^ uo •£> a- uno co u
11 • £■ •£■ '.£i *.£i ■•£' '.£i r. r . r. r . r. r . o:> co co co co co o- >? ■ >? • >?• >7- x x x x x x u a a a a n n m o 6 (
'J*0j "J >'0 '"'J OJ OJ |'|J OJ I'U OJ 0J CU 0J -'0 OJ CU OJ 0J OJ CU CU OJ OJ <'|J OJ OJ OJ CU >'|J CU CU OJ CU OJ CU OJ CU 0J CU 0
£' •£' • £• •£' •£• •£• •£' • £• •■£' l< •£' •£■ •■£• •£• '-£i •£< • £• •£' •£' •£> ■-£' •£' • £' •■£• •-£' •£' •£' • £' •■£• •£' • £• • £' '■£> •£' •■£> •■£< •£• •£' ••£' ■£' U
UJ Z
Lt X
=. uJ
=i _J
X —
X □
lit Lt
X X
I- X
</> u
Lt
z
X
•_> CJ
» LLl
o X Lt
; x i
i — c
i a l
X i/ t
</>
. >- uJ
I lit Lt
- X =4
• H- =»
L ) X
]
■ ►- X
>/> uJ
J X
=i N X
L=l •—< Ltl
X </> t-
: CO
U.
x
X
O lit
uJ X Lt
wQi-UJw
X I- X' 1=4
Cl □ X
*- —I Z h- L-)
Lt X □ <!' '/>
X 1 J 4- X UJ it
»- X X — Lt X '
W « □ - M =1 I
K P X O CJ .
> X CluJX
H- X <
. CO
■ l- X
I UJ X c
i X' CJ I
' X I.
J l 0 uJ l
. co i ;
Lt □
. CJ ►— X' CO
1 CO X CO
X 4- — UJ Lt
I Ul X 1=4 Lt X
- _J <-« I 1=4 X
:• □ a m j i
: a a. _i x
CO LL UJ
co a x
UJ CJ
t— C O □ X
X aJ i- a LL
ox ox
X UJ
X z
□ □
o o
J
: a. □
-J X
4X1 X
X
»— o
Z X
O X
*— CO
• CO II Ltj CO
: co
x x
) X X
XXX' CL
■ 4- X » X. X 4- x . x
1 x x a x x x x 1 □ □
> X' O' X CO X Z l£i '_' X _l
CO 4
»- 4- X
X <- X 0- X
Z A. Z /S X y\
O 1=4 O' X 4=1
. X
X A. o CO _J X X X □ X X X
J •—* *—1 Lt L_l Lt O X *-4 □ X' O' X' X
.xx O' > o x ;i x o x x o< =4
4— V' x X •» LM 4— v XX •* X •» 4=4
4- X CO 4- X 4- Z CO 4-4- > .1 il
CO UJ X II X X CO j 1 II UJ > X X
X X 4=1 X O' 4—
xxxxaxx x
O Z O X Z X X
X V VOX 0 a. X
X □ X □ CO X LM
X II X II I X CO
O Oi v X v X
X »X X X
4- X CO X - II X II X
X X X I □ X X
O' O > X X O X O'
X O O' XXX
-S
D X i
X X
«:• x ■:
' X X 3 O
• X X O X 1=4
A »- » I X »
:• co x co i x
X 4- X XI
I—4 LLj » »• •
•=• O' X X X X
r J X 4— 4—4 4—4 X 4— O' 1=4 4-"
CO 1=4 □ 4=1 o O X 4=1 >
X 0 □ 3 0 _J X CO X 3 X X X 3 O
'ixzxox«XKaaxa x 4=4 x 4- x x
' *-• X » X X ' 4=4 X □ □ .IX »I=4X X . X X »
4 X X X X CO I X '=• O' X X X • ' X X •=■ 'O X X CO X X
I -Q4— 4- X Z 19 —<
XX^^Xx □ XX X x
O z J X CO 1=4 X O' ® X
11 - j a. o □ h « a o o x i o* •=• - oj .1 x
4-4 X . O . I . . m . I X CD I . x . . 4-
O' X X 00 O' X X « 3 ^ w H O' X 3 X Z X O' O'
O' x _ _ __
n oxoxxi x xxgxxi«ox'i'ioxxaoaoSlo^iX'X'ioxrxxxocxoxzxv.r.inx^o2xx>xx>.rxr4x r -i i ' i ^x^§oo ^
' « L_I • . Vi X O *0 e- '_' 1 CO X X O' Z O • Z CO Z Z • ■ Z CO CO X O' O' Z O' “ ( :• CO X O' Z O' —■ CO X O' O' Z O' “• Z CO X O' Z X CO Z O' O' “ O' 1 E IJ E Z cl O “J
X
H-
X
Page 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
r- □
x c—
x □
I -J uJ
X
x a
it X a. UJ
■r tu t- cx.
x r □
o uj r t-
x a x ai </)
•x > h- □ x LU
X -X MKLL
t- UJ LL X I— ‘
X > i- — X ,
X X UJ — □ UJ
X CO IX ■_< X in
CL tt X I I I ' ' i
_l H H :
x :■ uj '
□ X
■ □ □ a. n x cj x x :
-I X X _J X
' _j y- uj • :• > _i x x i j a. k uj
'iuJhjDiXitiaiuht
Ct X X *-H □ l LL LL i
CO If
• iL x ■.
rf If' if if if if if' if'
t-i rf
•=• OJ
UJ Cm iT.
If If' <■£>
•£' •£' '£'
•=• UJ X
ll‘.i rf CO
— •=• U*'
OJ rf
rf — X
rf *r co
UJ •=• OJ
OJ in
u-. — >r
rf *t co
CO •=' OJ
OJ U*<
</)
X
' rf OJ
■ O .X
OJ 0"i
:• uj cm co r - oj «- >t.
:• r- >_■ oj cm i_i
• *t If CO O' x l
• i> '1. 'll ai •
• rf •=' rf •=• 1-4 CO rf *f •=• If rf •=• o rf O y. •=• rf ■=■ UJ CO U"' UJ CO
• OJ rf O If I OJ rt O U'l If' rf '=' rf OJ rf •=• rt OJ rf '=' rt OJ rf ■=■ rf rf rf rf If
I If' U. lm If' «■* •=• l-( OJ rt i_i ■-• rf •=• |Z| rf rt •=' Cm CO rf O t=4 •=• O' O' If '
• rf rf OJ rf rf OJ If rf CO O OJ rf OJ O rf rf CU ■=' rf rf CO O OJ rf rf rf ■
U. L
l=i rf rf O 0- h rf (J rf U0 L) If) O
rt U~> If i rf OJ CO rf |fi CO rf rf rf rf rf
X UJ CO X Ll rf O |f) O u* UJ CO <=■ rf O
rf rf rf OJ rf rf O rf CO rf rf If CO CO If) CO
co y« co rf uj cp co 0 * ■=• *-• o co O ' rf ir
rf rf CO rf If rf O Iff |fi |f. rf If If If If) CO
> )-4 Cm CO If' 'I P rf h O O CO UJ If CO •:
> rf CO U" 1 OJ rf CO rf rf CO CO If' rf rf If <
!' f-- tt w n|fi O'* Cm X
. r - r _ r -. co co co co co c
• CO CO CO CO CO CO CO CO CO c
■0 '£• ■•£' •■£' ••£' •£' •
• D • !' ' ll '.£) • !' '
I a . Cm CO f •- Cm Ll CO t - CO O '=' rf 0’.' CJ ® CO N CO X CO f -- Cm U. 0'' N
i Cm Cu i j u U M m P M LU UJ UJ UJ Ll U. U. Ll Ll O O •=• ^
' CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO CO rf rf rf rf rf rf
I 'Ll 'Ll • O 'll 'Ll ' Ll 'O ' 0 'Ll •£' •■£' '•£' 'Ll '-L' ' Ll 'O •■£• ' 0 ' 0 'Ll '-L' '0 ' 0 '.£> '.£) '■£'
I X □
; uj i-
I LL X
I UJ h-
X iJ X
i )“• >y>
H UJ l U >/.i t- Cx. Cx.
I— ■■ X Ll )— UJ
> LLl X OJ X LL LL f J
Cm iXi I i/f Z) X
CJ LL D X' Cm • ' a
)- X
< X t-
Cm X
. x uj i :
: uj > h ii i.
' _j □ uj __i :
i x x- x i
—' LU _L H rl Q. UJ K I- □ U. □ I h
I X X + X X X X J— XX)— X
. h '_"j □ h i uj □ h - ,=. X' >- —
1 _• X J X II J □ X x — X Cm x
I □ M X Cm 'I' I |_I I ' X " I' P « h ll
□
X X
X X
I— LJ r— im i/f Cl
n x x a »- □ -• i > x
-iXhKUHXHih r- -f 'n X i- _
x 'j xx xx x x co x u.
XXX • f— X X D (• h i- ll r-. iX X'»—
1 Li; X X X X X X X X Z> *■ lD _1 Cm X
X □ r-i <..■ ) i_i >-h t— i_i Cl X X' i-4 Cm u. •-< X CO X X
)- a x )— x a x x x x □ i— x x x ■ • x
x u-i xx x x □ t- j xx o x x •:> a z<
' X LM » X X ' I I— 71 > h- r Cm r (- I “i X X
i- a x □ > xx x •'!—<!- x i— u. a »-
1 X I— I O C □ H X u. r-Ofl u. Cm X i— • ■')
iwl □ □ X O )— X X . □ ll h- )— x
I X r 1-4 1,0 |_. W h X □ J r II x U I- j x X CO r- )- x
□ X Cj □
£. t- XX Cm h-
•- t- C O XX h- I . 0
□ XX XX XXX
X CO X m. O '— 1 1 •> X
co >r
X X
X X
X X
X 3 I-
□ _ X
X L-4 3'
•X X □
CO X X
,r • r
X CO I J
□ X X
X X
□ X
• J X
X CO z> CO
X CO
•x a □ x
XXX
□ - Cm
»- □ X efr
i CCi iX X X i
H X
□ CO
> X X c
:• X X
IIXIIJ-IXZIXI
I H h o I i
X X X X X in i_' X h- Q CO
H x X X N
□ X 1-1 CO CO .
» X r. r X X
X I— X X Cm
X CJ X X X C
X > X X *
'_' □ t- x :
X
• CO X N x
' x '=' ? 9 z ^ -'CDll iiaboraxMii-wZ'DDDD
' 1-1 ■' *. U m 1 X J X X □ ' h X X P m x I o x CO X □ X X X X
Cm in _j _j z. _J
1-MhJIJjMMXXt N hm JCt N
— UJ > X- X O X X X •_) □ X X > > X X
UlitXD J X J UJ M X □ x E '_' 1=1 “•
J-
X
_ j _ - J X
> x > X X 1=1
I u E J o -J
J J m X 'I J J
X X X X X -I X
_J __l —• X )•_' |_|
• L' x UJ CO If •:
•=• rf r _ oj u. •:
OJ rf 1 /
M U L
OJ
'J OJ OJ OJ OJ OJ OJ I'lJ OJ OJ
V 'V '•£' •£' ••£' *•£' • £■ ■ £' '£' • £'
CO rf
UJ UJ
•■•J OJ
• cu co — r --1
i i_i cu x r •- -
OJ ■=• Cm U'i L
' ’-i "-t Cm O'* UJ CO X Cm Cm Cm *
iOU.ll CO Cm nj LJ C
OJ OJ OJ I'lJ OJ
UJ UJ X X
OJ OJ OJ '-.J
'•£. ' Ll '.£i ' £i '.£i •
OJ CO rf l
XXXI
OJ oj nj
'•£' • £• • £' ■ £'
'.'J 00 UJ CO aj o AJ CO
•£) •-£• 'JJ *.£i '£i '-£i *.£i .f,
f- O ui no r. rt DO LU If CO X .Vi CiJ Cm U* y.
H -r UJ UJ CO •=• X '=' =' Cm '=' Cm ■=■ X X
Cm i_i f - CO UJ UJ M M CO UJ Q UJ n p ii I P n rf X m O
CO h- Cm •_) •=• 00 X' •=• O CO O CO CO O CO .'.j j Cm >r
• rt if I '.£• CO IwliJ *-< rf r - CO C
'•£' ••£' • £• • £• ••£' ••£'
'I w X r< rf y.i CO X Cm X OJ UO .
OJ CO CO CO CO CO CO CO 00 '
CO CO CO CO CO CO CO CO CO CO CO CO '
’•£> •£' • £' •■£' '•£' • £' ••£' •■£' • £' '.£i •.£• ■
Number 26
262
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 23
HIGH SPEED CASSETTE I/O
FOR THE KIM-1
I
BY THEODORE E. BRIDGE
54 Williamsburg Dr.
Springfield, MA 01108
This high speed cassette tape handler will load or dump at
12 times the speed of KIM-1 or twice the speed of the
MICRO-ADE 1 Editor-Assembler. It replaces and overlays the
editor routines CREAD and CWRITE at the end of the third
4K block of memory (2EA9-3000).
If you are not now using the MICRO-ADE 1 Editor-
Assembler, you should consider it. I think it is well worth the
$25 I paid for it.
Stand-alone operation is permitted with this high speed
tape handler. You may call it from any program as follows:
20 A9 2E JMS CREAD Cassette Read
20 54 2F JMS CWRITE Cassette Write
If your program is to call CWRITE, be sure it first loads the
starting and ending addresses as given on page 47 of the
KIM -1 User Manual. This is just as if you were dumping with
KIM-1 before starting at 1800.
You can use these high speed routines to dump from the
keypad. Load the addresses as with KIM-1, but instead of
starting at address 1800, start at address 2F54. You can also
load from keypad control. Instead of starting at 1873 with
KIM -1, start at 2EA9. This loader will save starting and ending
addresses ready for you to copy the file on cassette by starting
at 2F54.
Trade-offs
You pay a price for the increased speed. When you use the
MICRO-ADE editor, with its HYPERTAPE 2 tape dump, you
need a better cassette recorder than you would with KIM-1.
I have had good results with my Realistic 3 seventy dollar
recorder.
When you try to double the speed using these routines, you
lose compatibility with KIM-1 and you lose the search capa¬
bility of the monitor. You always load the next program on
the tape rather than hunt for the (ID) you want. You need a
meter on your recorder so that you can position the read head
just in front of the program you want to load. Also, you must
keep a journal showing the cassette number and the meter
reading for all data you record on tape. You really ought to do
this anyway.
Loss of the search capability is not altogether a disadvan¬
tage. If you have only one copy of a program on tape, a blip
on the tape may prevent your loading with the MICRO-ADE
loader. But with this high speed loader, even if you flag a
checksum error, most of the program will probably load
properly. I have found it helpful. Either way, you really need
two cassette recorders: one for input, and another for output.
You pay yet another price when you use these high speed
routines during an assembly. When you load the object tape,
it will reside at address 0200 where it was assembled instead of
at the ORG address where it belongs. After loading, you must
use the BLOCK MOVE command to put it in its proper loca¬
tion. After all units of your program have been properly
relocated, you must perform a SAVE operation to get a usable
object tape.
Apart from making a quicker compilation when using these
routines (even after relocating as described above), you can
also recover more quickly from checksum errors encountered
while reading the source tape during compilation. I have found
them very convenient for general housekeeping as well as for
compilation.
Description
These routines are similar to the MICRO-ADE HYPER¬
TAPE 2 routines that they replace. They simply gulp the entire
8 bit byte at once instead of taking it in two nybbles. Thus,
they go twice as fast. The CREAD routine cannot look for an
end-of-data symbol (“/” = 2F) to terminate the load as this
might appear anywhere in the data being loaded. Instead, it
reads the start and end addresses at the beginning of the tape.
It terminates the load when the loading address (VEB + 1,2)
equals or exceeds the end address. At the end, the display is
lit; so that you can see if a checksum error has occurred; and if
you have the right ID.
Since we are not loading ASCII characters, we lose the
validity check on each character as is made in the HYPERTAPE
program. We must depend on the checksum error to flag all
errors. This has not been a problem for me. Actually, I think
it is easier to recover from a checksum error when using these
Pa 9 e 24 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 26
263
high speed routines than when using the HYPERTAPE
routines.
At the end of a tape load, this high speed loader will halt
with the LED display showing:
00F9 (ID) if there was no checksum error, and
17F9 (ID) if there was a checksum error.
You look to see if the ID is the one you want. If you depress
(C = Continue) you will return to the calling program. If you
depress (B = Bad tape) you will read the next program on tape.
Of course, you can rewind to try again on the same data if you
wish. The VU-TAPE 2 featured by Jim Butterfield is incorpor¬
ated in this high speed loader. With it you can see the loader
lock on to the sync pulses when it starts to load.
At the end of a tape dump, you will halt with the LED
display lit. If you depress (C = Continue), you will return to
the calling program. If you depress (B = Begin) you will load
the next program on the input tape. If you depress (RS, AD,
2F54, GO), you will dump another copy of the data to the
output cassette.
Remote program control of the cassette recorders is
provided for in these high speed routines. I use the HELP
RELAY PACKAGE 4 . Application pin 11 activates the input
cassette, and pin 12 activates the output cassette. If you are
not now using automatic tape control, you should consider it.
Later, we will describe two patches: one to permit manual
tape control, and another to slow down the speed if your
cassette recorder can’t handle the high speed tapes.
Tape problems are not to be taken lightly. I have adopted
the following procedures to try to minimize these problems.
1. Always rewind before ejecting a tape.
2. Stop the recorder before removing remote control plug.
3. Use short tapes. Short tapes can be obtained from
PYRAMID DATA SYSTEMS 5 - five 10 minute tapes for
$3.00, or five 20 minute tapes for $3.25.
4. You need a medium quality cassette recorder. Robert
Tripp 4 reports good success with Panasonic RQ212 DAS,
and Radio Shack Realistic CTR 39 model 14-819.
To load these high speed routines from cassette, you use
the KIM-1 tape loader at 1873. Therefore, you must keep a
copy on cassette in HYPERTAPE or KIM-1 format. I can
furnish such a cassette for $4.00 or a paper tape for $2.00.
Patches
This patch for the Micro-Ade Assembler-Editor will link
with the high speed routines:
2E97 4C A9 2E JMPCREAD
2E9A 4C 4F 2F JMPCWRITE
This manual control patch will permit you to operate
without relays for program control of the cassette recorder:
2EA9 A9 1C LDAIM $1C
2EAB 85 FB STAPOINTH
2EAD 85 FA EA STA POINTL
2EBO 20 24 2F JSR DISP
On entering CREAD, this patch will display 1C1CXX on
the LEDS to remind you to start the input cassette immediate¬
ly after you depress C to continue with the reading of the
tape.
At the end of the load, the CREAD routine will display:
00F9 (ID) on the LEDs if there was no checksum error, and
17F9 (ID) if there was a checksum error. At this time, you
must remember to stop the input cassette before depressing C
to continue, or B to reread the tape.
On entering CWRITE, this patch will display OCOCXX to
remind you to start the output cassette and to wait a few
seconds before depressing C to continue with the dump:
2F56 85 FB STA POINTH
2F58 85 FA EA STA POINTL
2F5B 20 24 2F JSR DISP
Before leaving the CWRITE routine, this patch will display
COFF on the LEDs to remind you to turn off the output
cassette beofre depressing C to return to the calling program:
2FA4 A9 CO
2FA6 85 FB
2FA8 A9 FF
2FAA 85 FA
2FAC 4C 24 2F
LDAIM $CO
STA POINTH
LDAIM $FF
STA POINTL
JMP DISP
A patch to lower the recording speed is given at the end of
the listing. This patch is necessary only if your cassette record¬
er cannot handle the higher speed.
Conclusion
I think it is very worthwhile to speed up the tape opera¬
tions by use of these routines. I recently wrote a program to
compare the dental record of a corpse with up to 60,000
missing person records to seek a match. In writing this
program, I was very conscious of the need for faster cassette
reading. With these routines, it would take 4 hours to read
60,000 records. With HYPERTAPE it would take eight hours.
With the KIM-1 loader it would take 48 hours.
In writing a program like this HIGH SPEED I/O, with only
two overlays, the assembler reads the source tape twice to
edit and twice to compile. Also it spends the same time to
save a corrected copy, being equivalent to six reads. If we
make ten corrections during the debugging, we would spend
one hour for I/O using HYPERTAPE.
Furthermore, it is very convenient to use these routines
Stand-Alone. It is nice to do a little housekeeping without
needing to fire up the teletype and the Assembler-Editor.
Notes
1. MICRO-ADE^^ for the 6502 —Assembler, Disassembler, Editor,
by Peter F. Jennings. Micro-Ware Ltd., 27 Firstbrooke Road,
Toronto, Ontario, Canada, M4E 2L2.
2. The First Book of KIM, Hayden Book Co., Essex St., Rochelle Park,
N.J. 07662. Cat. 5119-0. $9.00.
3. Realistic^^ CTR-39, Model 14-819 by Radio Shack.
4. HELP RELAY PACKAGE, the Computerist, P.O. Box 3, S. Chelms¬
ford, MA 01824.
5. Pyramid Data Systems, 6 Terrace Ave., New Egypt, N.J. 08533.
Number 26
264
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Ul
to
V)
Ul
x
Q
Q
X
h
P
P
Ul
>
x
t—
U)
tO
V)
*
u
Ul
X
O H
§
o " 5
H Ul p
X O
Q o 2
Q H 4-4
X V)
X
Q
Q Ul
P to
J w
k—
Ul
H P
£5
H X
H U
>< W
Ul X
2 O
H H
0.
<
H
« 2
Ul 4-4
0. *
>*
X
x o
2 o H Ul
O H
C X % H
u, o s u
o vi
2
H
ft.
2
O
_
II H
uJ
X
Q 01 n vi
<
o
Ul
2
x <
o x
X X
X
CM C/1
X
H H CO O
X
X
u
V)
ul
Ul
O
u
X V)
>
CD 0
Ul
H X
u>
X
t-
X
<C X H Z
X
< & 2
X
UH O
>*
2
x
X
Q *-i p-* O
X X
X O O H
o
w
Q
Ul
•-«
H
k—
o
< X X
<X D
X H D
X
2
X
H
2
2
2 X
Q
H O
H
2
P
M
V) X (- X
CO H
H P E H
2
UJ t—
O
Ml
O
X
O
—
CM
<C X X p
X X
X X P D
X
VI V)
VI
o
u>
X
X
ca
ca
U vi i/i h
X X
VI i/l H O
+
+
X
P
X
h
X
X
2
H
X H
X
H
H
H
H
(M
(M
O'
<C
Q
X
•7
<
*-4
X
P
0 > x
t—
>
Q
X
X X
X
2
<a
<s
sO
X
<
H
>
CM
X
H
CO
o
X
<t
P X
H O
X
X
o
<
o
X X o
X
X
c-
X
X
u
2
X
V)
X
H
o
« X
X X
<i ^
CM
X
&
p
O
CO X
2 X
X
X
2
X
Q
X O P
X
Q
O
—•
ca
GJ
<a
M
X
2
2
x <2
x 2
vO
Q
o
*/>
X
VI
X
V) >
*-1 X
o
>
X
X
O <t X
o
<n
X
to
V)
VI
u)
VI
P
VI
Q
o
»—i
> X
> X
VI
V)
VI
M
X
2
V
2
2
2
H
Nil
H
N
D
X
X
<C
K -J
<1 <C X X
X
X
X
o
X
XXX
o
o
X
<c
<5
< <c
X
X
X
CJ
X
X
X
X
X
<C X
<0 10
X
<5 to
<
<5
X
X
V)
k-
X X
P H
to VI
V)
to
to
o
Vl
2 2 X
X X
2
H
P
X
H
to
VI
s
X
2
2
s CO
x s
Q X H
X
P H
p
H
H
X
"0 V)
P X
X V)
"0 *0
•o
"0
X
*0
□ a -d
VI
X
CO
X
o
CO
*0
"0
o
X
O
a
*0
*0
"3
X O
xxx
X x
X
X
X
P
<
Q
X
o
J
Q
3
X
Q
X
Q
X
§
ft.
to
UJ
>
|2
Q 4-4
H
X
O
Q
X
Ul
H
to
m
to cm ui co
<a <a :> u> q
uc-c-r'QmH^zU.f^
<a — u, — <tU2w3tQ-
2 2 £ 2 2
Sxqxxxkxxxx
QHZHQHtoQHQfr-
jvi<m JWO Jin JW)
ui
h
Sfc§
X
c-
O' x
o
c-
X
X
r-
X
c-
X
X
X
X
O'
7
7
r-
<31
c-
r-
C"
c-
O'
r-
CM
—
—
— CM
—
—
CM
CM
tM
“•
—
—
*-
CM
”•
—
— -«
—
—
—
—
—
X CO
Vl
r-
P o
CM CO
o
o
CO
CM
CO
c-
X
CO
CM
X cm q
CM
O'
< O
r- X
CM
O'
o
P c~
X
q
<C
CM
O'
O CO
r-
CM P O
CM
ca
X
co
ca <r
X
X
CO X
CO
■51
X
CO
X
q 1
X
Ca
q
X
ca
x ca ca
ca
MO
ca
ca
ca
X
<
X
X
X X
X
X
CM
X
MO
X
ca
ca
X
ca < X co
CM
X
X
q
cm ca
P
<C ca
O' Q
ca ca
ca
ca
ca
G>
ca
Q
ca
ca
co
p
ca
X Q O'
Q
ca
ca
O'
ca
O'
ca
o
CJ
ca
P Q
Q
Q
ca
ca
p
ca
m
Q
O'
Q
O'
Q O' p
5)
O'
in
O'
p
<a; cm
O'
u
—
<t CO
CM CM
CM
CM
CM
O'
CM
U
p
X
CO
X
p
co <t ca
X
CM
CM
CJ
X
o Q
q
q
CM
< o
<31
X
MO
CM
< MO
<31
CO
<31
CO
CM
CO < CO
CM
< CO <t CO
as
p
ca
co in
X
r-
CJ
X
q
in
co
A
C
F
q
r-
<S o
X
ca
CM
X
CO
X X
_
q
c-
co X
X
X
q
M>
O'
X X ca co
MO
co
< o
X
u.
X
X X
X X
X
ca
ca
ca
ca
<a
ca
—
CM
CM
CM
CM
X
CM
co
co
CO
CO
CO CO
q
q
q
q
q
q
q
in
in
in
V)
in m mo
MO
MO
M)
M>
MO
XXX
X
X
X X
X X
X
X
X
X
X
X
X
X X
X
X
XXX
X
X
X
X
X
X
u.
X
X
X
X X
X
X
X
X
X
X
X
X
X
X
X
XXX
X
X
X
X
X
CM CM
CM
CM
CM
X CM
CM CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM CM tM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
X CM
CM
CM
CM
CM
C\J
CM
CM
CM
CM
CM
CM
CM CM CM
CM
CM
CM
CM
CM
<s ca
ca
ca
ca
ca ca
ca ca
ca
ca
ca
<a
ca
ca
ca
ca
ca
ca
ca
ca ca ca
ca
ca
ca
ca
GO
ca
ca
ca
ca
ca
ca ca
ca
ca
ca
ca
ca
ca
ca
ca co
ca
ca
G>
ca
ca
ca ca ca
ca
ca
ca
SI
ca
f» co
O'
Ca
CM co
<7 uo
'O
c-
co
O'
ca
CM CO
q
Vi
MO
C" CD O'
ca
—«
CM
co
q
V)
MO
c-
co
O'
ca —
CM
CO
q
v>
MO
c-
co
O' II
—•
CM
MO
r-
co
O' ca -
CM
ro
q
in
MO
8
8
e-
<a
S £ ^ & £ 6 s
8
8
8
8
8
8
8
8
COQ'CC'O'ONQ'Q'ttG'C'Q'X
BcsSSISiIsSqSqSh
g
g
S
8
g
@ ca ca
5
S
s
ca
2 -
o r
x c
4-> |
r x
C -V
ul
P
J
o
J
.. o
*-• N.
i X . !-•
P O H
s, O UJ
>■ I
O i
J
J P UJ ,
4*J «.J — ■
X -• •- •» i
i.Q U C_
i .-4 I-. U, I
*** O' P tv 1 *
1 —• -• vjJ la ca
1 to) ;■) ul u’) vl
l CO q Ul «o,
i m U, »t
P VJ
X Ca
p x
ia —•
VI -)
tVl —• Ui
q q x
X t"
M> CO O' O CM X CJ
X Ui U. X CO CO i*J UJ
i td w w
lo ********
c -M m o
u - :A
r oOi
OhHI
o t_> _j i
2 O I
X fr '
o o
*****************
Z)
U
u
i-
2
—
s:
<
t—4
X
t—
X
o
u.
>-
p
X
X
Nt
X
o
z
P
>-•4
X
< 4 .
O
do
o
X
M
7
0 -
P
CJ
4-4
u)
P
l •
X
p
UJ
<
1-*
n
x
<£
0
O
p
H
II
<il
p
2
X
•7
u
p
<
p
u
►-4
;•»
H
0
u
17
X
2
P
2
1-4
4—4
4—1
H
p
V)
4 —.
O
l«l
P
t-.
X
2
p
>*
X
>-
p
P
o
■7
4-4
<
u.
P
>-
O
X
4—4
t-
►—4
t •
ft.
1-4
o
0
0.
—»
H
•p
C
H
UJ
Nil
l-
*-
0
H
>'
P
t-
VI
p
*7
X
X
4-t
X
Vi
X
X
X
p
P
l-
t J
CM
> i
X
X
4-4
X
vo
Nil
P
<C
>
oJ
. 4
X
P
P
p
X
X
vo
p
7
4_,
H
P
P
Vi
o
X
H
H
X
VI
X
-•
X
P
VI
X
VI
P
CO
CJ
H
—•
H
ca
H
P
Csi
CJ
■7
T*
q
4-4
P
O
u
q
U
PI
q
u
UJ
l"
t—i
.—t
X
co
p
p
V
*T»
r»
r~
MO
>-»
6
c-
<C
H
p
tie
—•
X
—•
X
o
o
c-
—•
Ul
p
X
Nil
—»
>•
p
CM
Vi
p
p
ul
11
Vl
tl
m
X
X
V)
VI
VI
Ul
X
O
u
O
V)
vl
VO
u.
VI
to)
*■-
X
*-*
2!
::
2
X
2
2
2
V
•—i
4-4
</,
<
u
■U
x
'-u
Ni.
X
•Ml
■Ml
U4
X
<C X
X
<
X
X
X
p
X
X
P
X
<t
P
H
-•
t—
p
H
4-1
e-
P
H
P
p
H
VO
VI
U.
H
2
2
VO
»—
*7
VI
X
X
•u
V)
P
t-1
P Vi
P
VI
U
p
VI
~0
P
O
VI
VI
U
Ui
•O
Vi
G
X
~0
Vi
i 3 :
b't-
l- 3> 3»
X C.-
r r_ >,
ON O' I
p ^ .
0
p
P
1 -
4—4
4-4
4-4
p
P
4-1
P X
p
*r*
_
P
X
X
fr-
4-4
0
77
4_
O
0
X
P
p
X
X
X
P
—»
—
p
l-
p
X
p
H
X
X
X
VI
X
VI
VJ
p
t—4
-
Z>
0
1 1
H
C-
C"
r-
X
C-
X
C-
X
r-
■“*
-•
—
—
CM
-*
CM
—
0
to
U4
cM
O'
X
C"
X
X
CO
CM
p
O
P
ca
M)
U
u
X
CM
p
X
it-
X
u.
X
r-
q
q
q
X
X
X
q
—
X
q
q
CM
X
q
p
X
0
p
O'
P
O'
Vr
O'
V;
O'
p
CO
O'
p
x
Mi
Ui
in
p
O'
Cu
p
p
ca
ca
p
V)
X
co
to
CO
X
CO
X
CO
X
co
P
X
co
cu
q
X
co
CO
O
P
CM
co
CJ
p
CM
co
CO
O'
O'
O'
0
O'
O'
O'
o-
c.
O'
O'
O'
O'
O'
o>
O'
O'
O'
O'
O'
p
14
P
Cl
Ui
O'
vl
p
ca
_
CO
VO
X
P
X
CM
q
M>
O
p
ca
CO
M>
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
. I
UJ
p
ft.
X
P
p
u
u
0
0
0
0
0
0
P
u
P
p
P
P
p
p
P
P
X
P
U4
P
p
p
p
4 1
p
ul
X
p
p
p
p
p
p
P
P
p
p
UJ
p
P
X
p
UJ
p
p
p
p
p
p
P
p
P
p
P
p
P
p
P
V\J
kVi
CJ
CJ
t\J
cJ
CvJ
tM
CM
CM
CM
tM
tM
CM
CM
tvJ
CM
CM
CJ
CJ
CM
CM
tM
CM
CM
CM
CM
CJ
CM
CM
CM
Cm
CM
CM
CM
CM
CM
OJ
CM
CM
CJ
«• >.-M —
X X X W.
C, o
V.V. l J *■
ix o.l. U U U c
Lf) M) C" CO O' ta
ol Csi O. U U i
UcJGWUuUtiu^CjlWUlCiiiiiC^CiJCjCilU’GtjGlCi
0 "ii -- '\l CW U‘; <JJ OLi O' c-i — CJ CO C Vi \D r- CO O'- X — CM co n Ui ^ C' CO O' CJ - Oi O Cf in NO C- C 1 J O' W O <f Ifi 'll
U « OJ fl CJ w w CM 04 tv. CM Cw CO O CJ CO CO O l‘J U O O <1 >J •C Cf <1 ^ C C C tfl u» ifj if) Ul l/) l/)
-it'lv..y<sj^v>fciu.Llui^>OtJut.ti{Jt.Otiicii v- bi v^ Cj M O O CJ Ck u SI tJ Cj M S S S a S L j CO B i^i ^
Page 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
265
>> I
X) c
*o
oj in
d-
O'
<T
N]
aj m
UJ
<j:
CU
Ui
2;
CL
f-
UJ
x
UJ
in 0
_s
CVJ
CM
<
ta
Ll.
0
ca
OJ u_
<T
U Pd
X
2
CVJ
2
3
J
X
_
!_«
0
CVJ
"O
UJ
UJ
O
VJ
ca
CM
0 ) T)
X
x
H
H
UJ
UJ
M C
0
0
X
H
Z-i
2
ra
UJ
X
2
6
nO
O'
0
O
Q
<a
fci
-L
H
H
H
03
U>
H
2
X
T» Li_
oj
OJ
■y
X
Z*
O
J
OJ
•y
ID
d' u_
UJ
x
m
oj
O
H
ts»
ta
*
dj rvj
d-
ca
x
H
CO
c
—
0
OJ
x x
u, <j; co
C' X UJ
-* CVJ —
H
JUh
X 2
CO — X
X X X
X O'
— OJ —
UOUOWtgC:
U. u M', n. k X
k k k k ui k
CU — CU CVJ CU Vi. C\J
4 — Q
J ” \ H M i-K
k) U 1 - J H h "
k <1 kJ o u k 6
2 X X k-s L'if- K1
O' X X X CVJ
<; U n k <T
UJ x ui X t>
CVJ CO —• C\i —
o x
X X
l, r»
CVJ —
UJ
UJ to
-k t—
tc UJ
H UJ
2 Si 2 5
Ot-OOK
o n k ,
I o ca r* 1
uJ -J 4- 4-*
i— 4- k x s. h
X 2 O o U k u
^XL_:roo_H4-*c:x
X O • ' - * ' • • — •
O X I
uJ Ul
Q Hi 1
ts]
w
to
0
H
UJ
J
tr|
W tr)
W
u w
>) TJ
0
0
O
Ul
X
2
0
u.
u.
i/|
H
s
TJ
OJ
X
u
CJ
40
IX
O
?
X
0
UJ
CfJ
<
j.
in
U
Q
UJ
UJ
2:
H
H
4 ->
OJ
0
U>
If/
ca
co
<U
la
<
CO
UO
—.
OJ
X
UJ
X
X
Q
Q
CU
II
II II
» II
I-
—«
u.
CM
CO
U,
0
Ui
<
l*.
u
u.
►a
O
in
M
u,
ca
UJ
u.
O
u.
w
UJ
va
u.
f'
va
UJ
2
in
dJ
•
UJ
CVl
ca
— •
CM
ca
CM
CM
—
ca cm
—•
va
vu
»-«
ro
JD
0)
M
4 -*
J
CJ
u
E
c
co
Q
J
H
2>
H
D
2
2
3
•H
— •
UJ
c;
X
1-
h
UJ
O
t-
CU
«—*
*—1
k
C
H
0
u.
0
:>
Q
0
2
X
CO
CU
2
H
a:
CU
«
h
-J
2 2
0
<£ H
»-*
O
J
0 1-
\
n.
u
CJ
CJ
0
2
Ul
_*•
<5
2
0
D
O
UI
<
M
UJ
in
(L
(U
>
ca
<C
U
0
Q
0
M
J
O
CU
C-.
CO
H
4 —
in oj o> o 1
UJ
m
r~
ca
ca
CVJ
CO
O
(U IU
-1 UJ
U«
ta
ca
u
ta
u
u.
0
►—k
n
c JO
L)
u.
NO
O'
t—
ro *h UJ
U.
^J -
<r
ta
NO
ca
ia
<C ca
ta
ca
M)
ca
ca
CM
CO
co
UI
cr
v£ ta
u.
u.
u.
0
u.
co
•q 1
O' <
u.
u
u
nO
ca
0
ta
t^
tr
c
CPTD H
Ca
CU
CU
CU
UJ
•H
C (U
O'
Q
U.
ca
CVJ
NO
CO
<C
«
0
Q
UJ
a
in
•H 4 -> _J
UJ
UJ
UJ
UJ
u.
lu
u.
u.
u.
u.
u
u.
u.
u.
UJ
3
T 3 n 0
UJ
UJ
u.
u.
U,
u.
u.
u.
u.
u.
lu
u.
u.
u.
u.
u.
UJ
D u B
tx
CM
CM
CVJ
CM
CM
CM
cvj
CVJ
CVJ
CU
CU
CM
CU
CU
U_
4-
O *H 2 ?
U
X
2
u
in
—*
H *D Jh
C ‘
O
X
u:
h
s
ta
<a
ca
G)
ca
ca
ca
«a
ta
ca
ia
ca
ca
ta
ta
“
"
co
<7 in
NO
c-
CO
O'
ca
—•
CM
CO
<7
in
O'
11
6
t^-
ta
L) Q
ca
t"
ca
t-
ta
s
s
e
8
8
8
8
8
6
H
h
1
BOS
UJhHh
> i-i 2 h O
^ZDo^^ko
h h o x u: in o'j h to
2
UJ
CO
ex
CM
t -4
m:
^s
UJ
H
CO
UJ
tu
<
2
4 —
II
Cs
U.
<C
H
6
UJ
Us
O
X
<
Ui
4 -
OJ
4 —
u
Ui
u
4 -*
2
k—4
H
kX
4 —
O
2
u
U.
2
X)
in
H
k-k
O
O
-a
oJ
UJ
Ui
.J
H
>•
2
<x
X
00
t-
•
u
vj
O
0
O
U
ul
H
O
0
UJ
—»
, ,
4 -
ca
UJ
>-
UJ
H
ul
Us
Us
y
<r
H
UJ
t 4
2
<
Us
Sr*
Us
2
CU
UJ
<A
tx
t—
(J
CM
X
o
4 —
U,
Ls
in
2
0
ul
X
X)
ul
UJ
UJ
H
k-r
u
Ul
2
UJ
H
tx
2
2
X<
t-
Q
O
2
—r
h
l *
0 J
uJ
X
UJ
ul
tx
U 1
r?
tx
S
CU
O
>s
u.
Ui
H
uo
in
10
•3
O'j
UJ
UJ
r
uJ
Us
O
H
fr-
0
<j;
h
4 -
t"
4 -
X
X
u
H
w
4 —
X
CM
CJ
Ul
X
O
O
<c
Ul
>
c.
J
O
X
0
V J
L_
u.
O
ca
M)
0
<Z h*
<x
•A
H
t-
UJ
t—
0
2
•r 4
h
X H
CU
O
l"
CO
o- (X
O
4 -
O
u.
H
CM
ca
<
D
X)
UJ
u>
2
*—*
X
Xj
X J
Cv
ca
s-S
—s
l/)
h
t ,
*n
X
0
tn
in
O
IX
>
0
k—r
UJ
O
O
0
0
vj
in
x
tl
.1
b)
O
H
O
4 -
Q
NS.
v
2
2
>•;
»■;
2
2
u.
*-H
*-•
►H
►-»
<5
k-t
k-k
X
X
lU
<1 IX
X
<
IX
>i
y u;
tx
u:
0 <c
tX
<c
Us
2
c:
iX
<
•X
X
U
X
» s
X u.
X
O
u
Q
OJ
UJ
U)
u
UJ
U)
UJ
tx
in
UJ
UJ
0
UJ
UJ
UJ
OJ
UJ
Q
in
UJ
ui
E*
0
H
X.
in
J
LJ
J
J
T>
J
J
J
"O
Q
UJ
•o
•O
"0
UJ
J
T>
J
n
-J
J
0
01
T)
U/
u.
*0
u.
Ul
<
0
H
Q
<C
tx
X
H
2
O
0
X)
y
Oi
, t
IX
u
X
X
u.
u,
r-
U,
u.
u.
l-
U,
c-
U,
Cs
o-
0-
Us
u.
CU
CU
CU
—
CM
CM
—
CM
—
CU
Cw
—
—
CVJ
Cvs
ta
vO
u<
< UI
<T
in
UJ
f-
0
Ul
CO
n
r~
UJ
CO
y
CU
■cr
Us
CU
CO
CU ^
_
U-l
U*
“*
<L CU
BJ
ca
u>
Ul
u.
UJ
U)
CO
u.
UJ
UJ
UJ
UJ
ta
Cm
x;
Cm
Cm
ca
IN/
IL
Ul
u.
CU
O'
<a
O'
ta
CM
UJ
Ui
<1
ta
ca
ca
ca
Cm
CJ
ca
UJ
ca
CU
O'
va
U
o>
y
U
UJ
CO
Cm
to
UJ
C
<1 CM
C
CU
<C
ul
CU
O
CU
CM
CM
O'
<
CM
vX CU
X.
CM
ca
co
■c/
00
•cr
CVi
UJ
0
u,
—
co
vO
co
tu
UJ
ta
CO
NO
0
0
u.
<J
£-
< ul
Us
■sT
0~;
O'
0
u.
CU
Ul
0
vO
t-
c-
c-
r-
r~
co
CO
CO
co
CO
CO
CO
O'
O'
O'
O'
O'
O'
<
•X
X
X.
X
LJ
»-s
1
k -4
u.
u.
u.
u.
u.
u.
u.
lu
u.
u.
u.
u.
u.
Us
u.
Us
u.
Us
u.
Us
Us
l '
u.
Us
U,
Us
Us
Us
Us
Ls
CM
CU
CM
CM
CM
CM
CM
CU
CU
CU
CM
CM
CU
CM
CM
CU
CU
CM
CM
CM
0 J
C'-
CM
CU
CU
CM
CU
CU
CM
CU
x
Us
v-s
X
LJ
l_s
X
X
0
u.
H
Li
X
a'*
*••
2
X
0
VM
X
X
4 -
X
UJ
la
-3
3:
O
•
X
X
ts
UJ
ui
Vj*
4 -*
U)
—>
O
X
X
—>
ia
X
4 •
X
0
2
i 0
X
X
Li
l!
X
X
p
Ul
X
—)
0
2
X
X
X
4 -
4 -
b
X
O
4 -
O
k-s
X
L
H
UJ
X
X
.4
CJ
O
X
CJ
•
X
u
0
Ui
L.
—>
X
0
Ul
X
X
X
*—k
UJ
H
4^
S-S
•
ul
4 -
H
2
X
0
tu
X
Ls
X
X
0
0
4 —
•—1
U a
LS
X
t—
>
H
l-
«r
0
H
4 —
-J >*
mJ
X
Z>
4 -
u>
Ul
X
t —1
4 -
'-S
X
'Ss
Ul
t-
X
X
>-
X
LJ
X
X
X
X
X
0
X
b
0
to
U)
Ui
X
C_J
X
X
UJ
0
0
0
X
X
4 -
X
2
ul
i-J
4 -
r-
X
CU
X
UJ
4 -
CO
tu
rJ
>r
X
X
<?
X
y
X
X
O
2
X
CJ
►J
CM
k-k
O
4 -«
X
c-
2
r-
-»
• 7 *
4 *
k-k
O
X
UJ
0
O
ia
Us
O
X
2
X
—s
b
13
s-S
<3
CO
—s
u;
b
UJ
X
0
S
O
v>
4 —
X
O
X
l/J
*0
4 —
X
X
vJ
If)
X
X
M
O
ifi
2
2
>*
>:
2
us
NJ
k-s
X
X
>_S
lJ
Ul
X
Us
0 >-
>s
>-
X
X
X
X
X I-*
X
X
X
X
X
N-C
X
O
X
f -«
4 -
Sr'
CJ
4 -
Ul
4 -
U)
H
4 —
X
H
Ul
X
HH
X
X
4 --
X
Q
4 -
(•
X
—>
UJ
tx
»—«
"O
-J
C|
-J
UJ
UJ
J
Ul
X
X
L 4
Ll
X
Ui
X
X
U 1
CJ
X
a
X*
X
0
2
H
UJ
4 —
H
X
2
k-l
H
O
X
lJ
4 —
2
4 —
>•
2
UJ
i-»
O
X)
u.
O
6
O
u.
O
H
Nl
M
O'
Ls
r~
X
c-
c-
CJ
—
CU
—
—
0
CO
CU
CU
UJ
O
X
<r
VJ
r-
X
X
•y
CJ
t)
CU
va
>r
CJ
Us
>r
Ca
X
Ca
X
X
X
X
X
if
X
X
ir
X
VV
■y
Us
Ls
X
va
ca
ca
la
va
>r
in
O'
jj
%n
0
X
va
O'
X
u>
O
X
in
'O
X
u
0
CU
X
CO
X
CO
co
-1
CO
<
vU
—
.J
w
X
y
co
co
O
X
CO
X
LI
LJ
ca
CU
*v
0
C“
.4
X
X
v J
Jj
Dj
Ll
L.
tu
<r
X
LI
n
Ul
»-j
0
0
O
u
0
O
X
X
UJ
^i
*.-1
X
X
LJ
k-J
X
X
Us
U,
X
X
Ls
Ls
u.
X
X
X
X
Us
X
ku
l.-.
X
X
X
X
X
X
cJ
CU
CU
CJ
cU
CU
CU
CU
cU
tu
CU
OJ
CU
OJ
Cd
CU
CJ
CU
tu
CU
tu
cU
Qca<aasjcaieii(S)Gc s icsJcatsiciJtacbJtutajc2Ciiviii A .^vic. i k-jc.iiiciikiJciwNii^Cit>c>iC J JvijGiCuc*iu^
co o cvj r> <7 i/j o r- co O' t-j — cvj co <r in no co O' — cvj cn o’ u; o c- w O' — cu to >1 u) no r- (vj n\
— r? r* & & £4 ^ <y CVJ CU CVJ i*> co co CO CO O 10 co - - •- -- - - - - G ^
Q O O (3 K O Q O O W ki CJ Q ^ (J Ci C.' Gi O l-i f - cd ic .j n Nj i? . ' ,
L U li ui a ti G >J k’
ii C CJ u O vi' k.' c. 01 wi k O
. - - -- - v . _ -• CVJ C> -y U) VO cx> o X -• CVi
5* jf ^ i 0 4Q in in in in uj in in in uj »n vo vo o O so uj vC vn r- d- t"
C! .V u G O Ll k il O vi t:l til 55 Cl X ci w k U l: t o v. v.4
Number 26
266
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 27
THE ZILOG Z-8
BY U. R. SOURCE
Zilog’s New Z-8 is the first of a new generation of single-
chip microcomputers. It is also capable of being used as an
8-bit microprocessor which can address up to 128K bytes of
external memory. The architecture of the chip is such that
under software control, it can be given a variety of different
I/O and memory configurations, the most important of which
are: a) an I/O intensive single-chip microcomputer and b) a
memory intensive microprocessor with up to 64K bytes of
data and 64K bytes of program memory. Such flexibility is
made possible by merging the multiplexed data/address bus
(and the associated control signals) with the I/O-oriented
ports. Thus external memory can be addressed while as many
I/O lines are needed can be maintained.
I/O
The Z-8 has a total of 32 pins dedicated to I/O. They are
arranged as four 8-line ports and are capable of being config¬
ured for input, output or bidirectional operation; They all
have pull-ups and pull-downs compatible with TTL loads. In
addition, all ports are programmable to provide status signals,
timing and parallel or serial I/O features with or without hand¬
shake.
Port 1 can be used as a byte I/O port or bidirectionally in
conjunction with Port 0 for accessing external memory. In the
latter application, the lower 8 bits of the address are multi¬
plexed with data. If more than 256 external memory locations
must be accessed, the upper 4 or 8 bits of the address are pro¬
vided by Port 0.
Port 0 is nibble programmable as either address or I/O. If
the address requirements are 12 bits or less, the upper 4 bits of
Port 0 can be independently configured as I/O while using the
lower 4 bits in conjunction with Port 1 for addressing.
Port 2 has 8 buffered lines which can be programmed in bit
mode as inputs or outputs. The output buffers can be pro¬
grammed to inhibit the active pull-ups and thus provide open-
drain outputs.
Port 3 is a control port and an I/O port. Its 8 lines are fixed
directionally as four in and four out. In addition, two of its
lines can be programmed as a full-duplex serial asynchronous
receiver/transmitter. Port 3 provides handshake control lines
RDY and STB for the other 3 ports when required. Other con¬
trol functions of Port 3 include timer in and out, status out
and interrupt request.
When the two lines of Port 3 are programmed as the full-
duplex asynchronous receiver/transmitter, a bit rate of up to
62.6K bits per second can be generated with the crystal fre¬
quency at the maximum of 8MHz (4MHZ true internal opera¬
tion). This configuration also provides for programmable odd
parity.
Interrupts
The Z-8 has six maskable and prioritized interrupts as well
as reset, which acts as a vectored nonmaskable interrupt of
highest priority. The six sources of interrupt are the four input
lines of Port 3 and the two timers, TO and Tl. There is an In¬
terrupt Request Register for storing the requests. The Inter¬
rupt Mask Register can store bits to disable the six interrupts
individually or use a seventh bit for a global disable of all in¬
terrupts except reset.
In handling prioritized interrupts, the priority encoder, con¬
trolled by the Interrupt Priority Register, outputs an address
which points to a vector in program memory. When the inter¬
rupt is serviced, the Z-8 globally disables all other interrupts,
pushes flags and program counter onto the stack and branches
to the location specified by the vector. Disabled interrupts can
be re-enabled either globally or individually and the use of
separate Interrupt Request and Mask registers makes it possi¬
ble to use interrupt nesting and interrupt polling together.
Z8 Block Diagram
OUTPUT INPUT
XTAL AS DS R/W RESET
(Bit Programmable)
(Byte Programmable) (Nibble Programmable)
Page 28
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Number 26
267
The Z-8 is equipped with two internal 8-bit counters with
individual 6-bit prescalers. The counter/timer circuits can op¬
erate independently of the processor instruction sequence and
thus unburden the program from such functions as event
counting and timekeeping. They have two user-selectable
clock sources: the microprocessor clock (maximum internal
operation of 4MHz) divided by four, or the external timer
input line at Port 3 can function as a external clock source
(max 1MHz), a trigger input (which can also be retriggered),
or as a gate input for the internal clock.
The prescalers can be programmed to divide their input fre¬
quency by any number from 1 to 64. The counters count
down from any number from 1 to 256 which is stored in a
holding register. At the end of the count, an interrupt request
is generated. The two software-controlled operating modes for
the counters are: a) stop at zero, and b) automatic reload and
continue count. The counter/prescalers can be started, then
stopped anywhere in the count; they can then be restarted
anywhere in the count or restarted at the initial value. One of
the Port 3 lines serves as a timer output for Timers 0 and 1 or
for the internal clock. It toggles each time the end of a count
is reached.
CPU
The Z-8 can access an internal Program Memory, external
Program Memory, external Data Memory and an internal
Register File. These different memories are implemented as
separate address spaces and other address such as I/O and con¬
trol registers are mapped into the Register File.
The first 2K bytes of Program Memory are on-chip mask-
programmable ROM. The first 14 bytes of this on-chip mem¬
ory contain the address for vectoring the reset and six inter¬
rupts to the proper locations in Program Memory. At addresses
above 2048, the CPU automatically addresses external Pro¬
gram Memory.
In addition to the 64K of Program Memory, the Z-8 can
directly address up to 64K of external Data Memory using
Port 1 and if necessary, all or part of Port 0 as described above
in the secion on I/O.
The internal Register File consists of 4 I/O port registers,
124 general purpose registers and 16 status and control regis¬
ters for setting the various configurations of the Z-8. This lat¬
ter group includes the input and output registers for the full-
duplex asynchronous receiver/transmitter. The Register File
is organized into 9 working register groups of 16 registers each.
The current group of working registers is selected by a register
pointer. The working registers within the current group require
only a 4-bit address field.
The fact that the I/O and control registers are mapped into
the Register File allows any instruction to process I/O or con¬
trol information and thus eliminates the need for specialized
instructions. Each of the 124 general purpose registers can
serve as an accumulator, a pointer or an index register, and
registers and register pairs may be directly or indirectly ad¬
dressed.
The lowest group of working registers includes the four I/O
ports. For I/O intensive operations and interrupt handling, the
register pointer may be set to this group and fast instructions
used to address the four I/O registers while using the 12 re¬
maining registers for temporary storage and calculation. In like
manner, all the registers for timers, port operation, serial inter¬
face and interrupt control are included in another working
register group so that when the register pointer is set to it
those sections of program dealing with system configuration
can be substantially reduced in size.
In addition to these, the remaining seven groups may be in¬
dicated by the register pointer to perform calculations and
other program operations. The Z-8 can still access them direct¬
ly at any time regardless of the value of the register pointer.
Instruction Set
The Z-8 provides six main addressing modes: Register (R),
Indirect Register (IR), Immediate (IM), Direct Address (DA),
Relative Address (RA) and Indexed (X). There are in addition
other addressing modes implied by certain instructions (Auto¬
increment, Register Pair and Indirect Register Pair). Basically,
all instructions can use the Register, Indirect Register and Im¬
mediate addressing modes. The Load instmction may also use
Indexed Addressing and Program Memory space instructions
use 16 and 8-bit Relative Address modes. These register ad¬
dressing modes can imply any register in the Register File of
ony one of the 16 working registers. The Z-8 instructions per¬
mit the addressing of registers in the Register File or working
registers or a combination of the two when two addressing
modes are used.
The fact that the I/O and control registers are mapped into
the Register File means that any register instruction can exe¬
cute I/O or control operations. Using the working register con¬
cept, a programmer can execute an input or output operation
between any I/O port and any Register File location in only
two bytes (6 cycles).
The six levels of vectored interrupts—maskable and priori¬
tized under software control—plus the capability of mixing in¬
terrupts and polling give the Z-8 a very flexible interrupt
structure. To support this interrupt structure, the Z-8 is pro¬
vided with a flexible stack scheme and fast context switching
capability. Context switching is the saving and restoring of
such pertinent information as flags and working registers when
an interrupt occurs.
The Z-8 can use an internal or external stack limited only
by the available memory and all under software control. One
of the registers or register pairs in the Register File contains
an 8-bit or 16-bit stack pointer. The stack is utilized by Call
instructions to the 16-bit return value of the program counter.
When interrrupts occur, the 16-bit program counter and an
8-bit flag register are automatically saved on the stack. Push
and Pop instructions can also save any register from the Regis¬
ter File on the stack. Any bit within any byte in the Register
File can be set, reset and tested by the Z-8 including any I/O
port and control registers. Thus, any byte can be used as a flag
byte to be set, reset and tested by a single instruction.
In the Direct Addressing mode, the 16-bit addresses for
jumps and calls are contained in 3-byte instructions. Indirect
jumps and calls are 2-byte instructions which point to the
register pair containing the actual 16-bit destination address.
Two instructions which operate on 16-bit values stored in
register pairs are Increment Word and Decrement Word. They
manipulate 16-bit addresses for Program Memory and external
Data Memory and can also be applied to 16-bit data words.
High-speed block transfers between external memory and
the Register File in the Z-8 occur with the Load Constant
Autoincrement and Load External Autoincrement operations.
Number 26
268
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
These instructions automatically increment the source and
destination address much the same way as the DMA operation.
Other forms of address manipulation are possible for block
transfers such as using Load Constant and Load External in¬
structions in conjunction with the increment/decrement byte
and word instructions. The following is a summary of the
Z-8 instruction set:
• Load and Exchange. Clear, Exchange, Load, Load Con¬
stant, Load External, Pop, Push.
• Arithmetic. Add, Add With Carry, Decimal Adjust, Decre¬
ment Byte And Word, Increment Byte And Word, Subtract,
Subtract With Carry.
• Logical. AND, Compare, Complement, OR, Exclusive OR.
• Program Control. Call; Decrement And Jump On Non-
Zero; Interrupt Return; Jump Conditional; Jump Relative
Conditional; Return; Set, Reset and Complement of Carry
Flag.
• Bit Manipulation. Test Under Mask, Test Complement
Under Mask.
• Rotate and Shift. Rotate Left, Rotate Left Circular, Rotate
Right, Rotate Right Circular, Shift Right Arithmetic, Swap
Nibbles.
• Block Transfer. Load Constant Autoincrement, Load
External Autoincrement.
• CPU Control. Disable Interrupts, Enable Interrupts, No Op,
Set Register Pointer.
When operating on working register data, most one- and
two-operand instructions in the Z-8 require 6 T-cycles. This is
the minimum instruction execution time. With a crystal
frequency of 8MHz (giving a true internal operation frequency
of 4MHz), one T-cycle is 250ns. Two-operand instructions
manipulating Register File data generally execute in 9 T-
cycles. The longest instruction, CALL, takes 19 T-cycles.
TEST FOR SWTPC GRAPHICS DISPLAY
Dear Dr. Dobbs, Received: 78 May 11
The following is a program which I have found quite useful
in hardware debugging my SWTP GT-6144.1 hope some other
readers will benefit by it.
The program should be self explanatory. It is relocatable
to other memory locations as the following MIKBUG dumps
show. The first one is from the enclosed program:
P
SI 13 AO 14FEA0028600A70186FF A7008634A701BD1F
S10C A024E05 5FEA002A70020F69D
The next one is from the program which was reassembled to
start at $0100:
P
S1130100FE A0028600A70186FF A7008634A701BDD2
S10C0110E05 5 FE A002A70020F650
Those who are not familiar with MIKBUG may notice that the
last byte on each line is different. This is the checksum gen¬
erated by MIKBUG and reflects the different address (2nd and
3rd bytes) in each line.
Sincerely, P.O. Box 60725
Jim Lanford Sunnyvale, CA 94088
NAM GTTEST
a TEST program for the SWTP GT-6144
graphics display unit.
written by Jim Lanford
for the SWTP 6800 using MIKBUG
this is a quick and dirty data inputer
-it inputs hex from the terminal
-thru the MP-La (port address at A002)
-to the GT-6144 (usually hooked to the M A“
side of the MP-La)
-this test program will also work on the “B“
side of the MP-La if it is jumpered for output
and the port address + 2 is in location A002
This program is very useful for hardware
types who want to debug the GT-6144 under a
controlled, one-byte-at-a-time environment.
It is also useful for some specialized
software display bugs.
If you get lost or type a non-HEX digit, the
program returns to MIKBUG, and is warm started
by typing “G".
The HEX address of the MP-La parallel
interface should be set in location A002/3.
Port t3 (800C) is usually used.
GT-6144 Data reminders
Horz bit select t> write $40 -> $7F
Horz bit select & erase $00 -> $3F
Vertical bit select.... $80 -> $DF
$F0 « invert screen
$F1 ■ normal screen
$F2 - enable CT-1024
$F3 - disable CT-1024
$F4 * enable graphics
$F5 ■ disable graphics
MIKBUG subroutine
E055
BYTE EQU
5E055
inputs two HEX char.
• register addresses a
nd select definitions
A00 2
PIALOC EQU
SA002
PIA port address from A002
0001
CR EQU
1
control register
0000
DDR EQU
0
data direction register
0000
OR EQU
0
output register
0000
SELDDR EQU
$00
select DDR
00FF
DEFOUT EQU
$ FF
define all bits output
0034
SELOR EQU
$34
select OR
• initialize
6820
A014
ORG
$A014
A014
FE
A 0
02
LDX
PIALOC
get port address from memor'
A017
86
00
LDA A
*SELDDR
A019
A7
01
STA A
CR, X
select DDR via CR
A01B
86
FF
LDA A
♦DEFOUT
A01D
A 7
0 0
STA A
DDR, X
all bits output in DDR
A01F
86
34
LDA A
♦SELOR
A021
A7
01
STA A
CR, X
select OR via CR
* input/output loop
A023
BD
E0
55
LOOP JSR
BYTE
input a byte
A026
FE
A 0
02
LDX
PIALOC
reload index to allow warm
A029
A7
00
STA A
OR, X
output to GT-6144
A0 2B
20
F6
BRA
LOOP
do it again
END
NO ERROR(S) DETECTED
SYMBOL TABLE:
BYTE E055
CR
0001
DDR
0000
DEFOUT
00FF
LOOP
A023
OR
0000
PIALOC
A002
SELDDR
0000
SELOR
0034
MAILING LIST SHOP-AROUND
Dated: 78 April 13
Here at PCC we are collecting sources of mailing list pro¬
grams, especially those with enough coding space for use by
small magazines. This is not only for our own continued well
being, it seems that there is a tremendous variety of people
and businesses which use mailing lists—from salesmen to
public interest lobbyists. We’d like to invite our readership to
send us any sources, or suggestions in this project. If our
research uncovers anything of interest, we’ll try to let you
know.
William Bruneau,
Circulation Manager
Page 30
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
LAZARUS
A Program to Resurrect BASIC Programs on
the Apple-11 Computer
BY ANDY HERTZFELD
2220 Dwight Way, #210
Berkeley CA 94704
(415)548-3072
Many unfortunate souls have experienced the frustration
which occurs when you realize that you have just accidentally
erased the program you were working on. Kicking the compu¬
ter may provide some emotional satisfaction but it won’t bring
your program back. This article describes Lazarus, a short ma¬
chine language program which can resurrect inadvertently e-
rased BASIC programs on the Apple-II computer.
When an Apple-II integer BASIC program is erased, it is
usually not destroyed. It is probably still sitting around some¬
where in memory; however, the BASIC interpreter no longer
knows where to find it so it is effectively lost. Lazarus scans
through memory trying to find the largest valid BASIC pro¬
gram that it can. If it finds one it resets the interpreter’s point¬
ers to point to the found program, thereby resurrecting it. If
no valid program can be found an error message is printed. In
either case control is returned to the BASIC interpreter.
Of course, things are not quite this simple. If there are
many program fragments floating around the workspace,
Lazarus might not resurrect the one you are interested in. If
you had performed some deletions of low-numbered state¬
ments prior to the erasure, Lazarus may restore the deleted
lines along with the rest of the program. If your program was
located in an unusual part of memory, Lazarus may not know
where to look for it. Finally it is possible but unlikely that
Lazarus could introduce spurious statement at the beginning
and end of the resuscitated program. In practice these prob¬
lems are rare; Lazarus should be successful most of the time.
The Details
To understand how Lazarus works, you must first know
something about the internal representation of an Apple-II
integer BASIC program. We will examine this briefly here; for
a more detailed exposition see Steve Wozniak’s article in Dr.
Dobb’s #23 (vol. 3, issue 3) or the Apple reference material
when they finally get around to putting it out (the current
reference manual isn’t very helpful).
The BASIC “workspace” is the area of memory used to
store the currently active BASIC program and its associated
variables. On the Apple-II it is defined by two zero-page point¬
ers: LOMEM, which points to the lowest addresses byte in the
workspace and HIMEM, which points one past the highest.
Program statements are placed into memory starting at
HIMEM and are pushed down as each successive statement is
entered. Another pointer called PP (for program pointer) is
used to point to the first, lowest numbered statement. PP de¬
creases as the program grows; a program is erased by setting PP
to HIMEM. Thus all Lazarus has to do is scan memory from
LOMEM to HIMEM and isolate the beginning and end of the
longest BASIC program residing there. To accomplish the res¬
urrection, it simply stores the address of the start of the pro¬
gram into PP and its ending address (plus 1) into HIMEM.
As each line of BASIC program is entered, it is translated
into a compact internal form consisting of four parts. First
there is a length byte indicating the total length of the state¬
ment. It is followed by a 2-byte line number, low order byte
first. Next comes a string of code syllables or tokens which
make up the body of the statement. Finally there is a special
end-of-statement token ($01) at the end of every statement.
Knowing this information, it is not too hard to find a
BASIC program segment; simply scan through memory search¬
ing for an end-of-statement token. When one is found we can
check if it ends a stanement by examining length bytes. The
fact that the statement’s line numbers must be in ascending or¬
der is used to perform an additional validity check. The pro¬
gram segment ends as soon as this structure is violated.
There may be many valid fragments floating around the
workspace (like pieces of the Startrek program you played an
hour ago); Lazarus will resurrect the largest one since that is
usually the one we are interested in. Since that is not always
the one we want, another entry point is provided that causes
the last segment (which tends to be the most recent pro¬
gram worked on) to be chosen.
Lazarus was implemented using SWEET 16, a very useful
little 16-bit virtual machine that is interpreted by the Apple-
II firmware. SWEET 16 saves a lot of code at the expense of a
significantly longer execution time. Since Lazarus does a lot
of 16-bit operations, Sweet 16 was able to spare me a large a-
mount of tedious coding. (See Woznick’s article in the Nov 77
Byte for a detailed description of SWEET 16).
Using Lazarus
The code for Lazarus is relocatable since all of its branches
are relative and the only local storage it uses is in page zero.
$300 seems to be a convenient place to load it. You can load it
for the first time by going into the monitor mode and typing:
Number 26
270
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E f Menlo Park, CA 94025
DO 02 A9
0^1 00 16
59 42 D5
44 D5 07
05 04 29
05 00 84
BC 01 EF
02 AB 21
2B 71 11
20 2D FF
00 85 FO
4A 00 17
07 F8 22
12 27 D4
38 01 E3
D1 06 OD
29 32 E2
3A 24 3B
4C 00 2C
4C 03 EO
85 FI 20
4C 00 66
FO 38 39
05 OE 24
22 FO 34
El 10 FF
B4 31 18
29 3C 01
EO 71 00
BO 3A EO
67 37 22
D3 02 18
68 31 E4
D1 F4 F4
02 CO 24
68 06 04
06 11 11
FF 4C 03
Once it has been manually loaded, it can be saved on tape
by typing “300.3AOW” and then subsequently loaded back in
by typing “300.3 AO R”.
Lazarus is very easy to use. After cursing yourself out a few
times for accidentally erasing your program, return to monitor
mode and load Lazarus. Then return to BASIC and type
“CALL 768” or “CALL 772”. The former will cause the long¬
est program segment in the workspace to be restored; the lat¬
ter will cause the last to be selected. When it returns, do a
“LIST” to see what it found. If nothing could be dredged up,
an error message is printed. If both entry points recover the
wrong program, you can adjust LOMEM and HIMEM accord¬
ingly and try again. If all else fails, you can still always kick
the computer.
A useful extension to Lazarus would be to recover the vari¬
able table along with the program, which could be very impor¬
tant in some cases. I would like to thank Bruce Tognazzini for
providing the initial idea for this program.
A complete source listing follows...
increasing
"neinory free 5 paQo
Mdtess^
- uomEv\
PV
UndofiOnoblOll*)
pro 3 r Mn)
BASIC. vJOrtepace. memory map
- PlftEfA
□ (EO© 1*3
lemtVi line number uxttftjUnWtsj erei-0f.si5re.mtnv
tt*- tody of ■tV'ie *+okt.o
£flSlC statemerit representation
4 h c
w o
p
c
0 0
0
P E
hD 0 PT 3 XOAd-P
c
3
c
E
0
0 P 0 o
Ad
• 0 0
CP *P 0 O rH
0
w o
0 c
0 o
r x c
E
C 0 >3 C 3 X
O
X 3 P P
0 > C rH 0 P 0
p
•P 4 h
C 0
X 3 P
E P
0
- ? X 0 c
P
C W 0
•H X 0 0 TIP >
c
O to P
O 0
o a
P
0 - Ad -P T 3
3 P
p > c >3 co a
•*H
E w
0
E rP
X
0
5 0 P O P C
P
O 0 W
5 X 0 C 0 X 0 -P
WOW
0 -P
»P ip
3
sc s
P
h X P C 0
0 c
4 h >
0 P 0 -P r il
C a C
c
rP rP £
vO E
4 h W 0 S 3
w
4 h 0 0 O
X 0
•P T 3
C h£) C 0 P W
o o c
he E
0 0 O
tP 3 0
o SOS
1
•P C c /1 O (O
p E
C W • -P
C he W X W C P
w C w 0
O 0
C p
Vh
0 0 O X
0
0 W T 3 rH
0 0 P P 0 0 *P
•H (Uml 4 h
c c
O 0 O -P
Eh O *P
h 4 w X X
o
0 ? C 0 r rl •
O P
0 0 0 0
C O C
a td
P Ad P 5
W 0 CO
W o 0
1
0 OX P 0
P 0
X O X >
P P W 0 •
0 w 0 o
o
0 W
r r}
O O 0 O O to o
X 3
W 4 h X 3 P 0 O to
P
O O
0 -p - T 3 0 X P
o- cx C C W P
P c
hC’p ho
0 X
P P C P P .P P
C
•P X C*P
W 3 0 P
OX P rH X O
p
£ w £ 0 0 C
w x
0 0 0
CO X 0
0
O >3 P-P rH
C 1
0 W 0 C
PP 0 O OPCC
0 X 3 0 OOT 3 0
0
P E
vrxrxxs • vo 0 O'-
P - H 3 W 0
X C 0
C C X 0
coco wwCPE
hi p
4 h >j 4 -. P
C
cc x 0 s x -p cc
c
S rH P P -P
o o
C o
W 0.3 CLP W
E
0 0 3 CK:
C W
0
0 O O
W p
0
P 'll 0 A!-PPP
a i
P O W 0
X 3 WW 5 3 P P
C
p C J C XJX 3 O 00
0 0
P ? P P
P c c
p p p S p -p P
W S C O *P
X 3
C -PC
P O 0 -P
hi
C O Ad O CCVhEw
rp rp
0 rH 0 0
C 0 0
0 0 0 FH 0 C 0
c
0 M -P .P W 4 h C
o c
0 w
X. Ad 0 -P C Ad X
•p 4 h O 4 h 0 0 hf
W 0 W W
0 to to
w w hC X w -p w
o
P X 4 h P,.P *P -P
p 0
E Ad S P
E O Ad O 4 h
O 0 * 3 0 0 X
0 0
4 h
0 O Ctl w
cx JD »P C C to W 0
x x
P 0 S O
X OE-P X X.-P
c
m O O-p E
p p
c
0 XhE
C - <H<H in X
0
POX
Q Q
>3 0 W >3 W 0 <H
o o
o
W 0
►p i—i
0
L) O C C C CCEEO
w w
s s
w
X
>3 C X
X X
P
vO
r il E
w o
0 P O P
X 0 H 02 S E 4 h S
hi hi
E S
0
z o
CO > - 4 - >
•P c P p P W W X 3 T 3 -H OS
0 0
w
Eh
O M
O X
ccxrAZOv^J-Xvnz
X-PCXCSS 00 X, S
rP rp
|i. KO
CLJ
4 PX
q z
o -p q o
K^XHXXiXH
3 0 O 3 OQKHWW 0 14 h
4-1 4 -h
Cl, O O O r-i
'il O
X CM »P
4 h rH 3
X
0 EO 0 OXX 33 EXX
P 3 hfAh, Cl,
•
O rH O vx rxvo MCiOWKN
•
CM CN-r-lXVfX-<(XJOCOO
0 O 0
0 0
O
coxxxxxxx<wxx' 3 'x
0
CC X«<WxSXKKft;
0 > 4 h P
X X o Q x cm
-C X
P
c
P >3
ZQSZqxQSZ
p p
0
0
0 W W X
MXOX-dtoXoX
c'll << <
CC CQ
X Ep Eh £h Q Q
X
X P, CM
X
T 3 E -P
P
rH CM r ~'-4 vrvvo 6 -CD (>H rH rH
w w
Q Z Q Eh Eh
•
MDEHZEfaWWQtffHQtf
Q S O Q S Z Q
O EH Eh
•PC P
KEOCKKKKKKKKa
p 0 p w r/i
W
PWWHWWWWPWwiPW
w
rH o m M o ffl p
TS O 0 W
0 0
c
p
C «M C 0
X
*
w w
0
c
o
p
0
o
O 0
o
O
p
o
D.-O 0
X
o o
rn
•p
rP
0 -P X
«
rxrx
X
hi
P-rH P
o
0
a
FP
P O 0
Eh
C
o
c
C O > O
p p
00
o
s
•P rH C P
c c
rH
O -P
•P .P
to
O O O
o o
•p
CC
O O O
c
C C P
rp
•p
W -P 0 C
**************
O' o O'xnxn
*< Q <00 00
O CM -4vO 00
OOOOO
c r '> tn f r ' f r '>c*>
O O •< O C^-nOvO MNP
cm pq r> w c r VrH ,p »p vo rx cwc o
•<QUli.OH 4 L'<mOQU
0000*P.PrH*P«P«PrH»PrH
(nmtntntn m\ m r r v m m c^v m m
•H 5
X O X o
P.
rH +■>
P O CON
C 4 H 3 a
h o h rv .4 vncNcoo^
rHCMCMCMCMCMCMCMCMCM
c r vc r vr'c r Nr'\rNC'vc r vc'\r r \
co 00 ex cm ov -4 -4 w e'¬
er} .4 Q o < rx-d- Q o
tq o D W O h (M rx-xf
CMCMCMCMf^rxrxrxr-i
px rx ox px rx px px px px
Page 32
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
271
NEEDED: SYSTEM IDEAS FOR THE BLIND
■a
>> 3
01 -H O
X © «M
P P
© b£
—H C
• P *H
0 ) ftx
• o p
■H P O
—' ft c
ft
© rf «m
W »H
P s
3 r q =
oscc
O M 02
X M
w =
P X
•H q P
3 q
C -H
3 ft P
p a. ft
W P
as a> •
X C/J p
O • ©
P
HS ft
W P
C s 0J
•HHP
(dx q
E -H
•a
© © o
X X H
P O GO
CO C
C © cq
0) P
X 0)
5 OT X
rt P
p x
c o
•H P P
O 0)
ftp c:
Ct P
W *H 3
•HOP
X P 0)
P P
c
x co c
a o 0 )
© ot X
0) p
P c:
•H X
© © C
3c E ©
P 2
g>S
P EH
ftX
ft p
3 PQ)
P'0
« 0)0*
© rH
© © C
X © «M
V. cm
P TJ S *rH CV
£ C O
O O
-H C
O O
bf
•H
E O ©VA
*m *H OT
P OT
>> O
P Xvn
O OT OT
P OT
© ©
X ftCVl P
©
O rH ©
© • P
P P
P o
VArH OX
N OX
OT TJ
•H PvO © PP
•H P X
TJ
X
OT © ©
O ©
P 2
O >*0
M
P
q rq
P © OP
© ©
©
© 2
X ©
X OT X
ft X
E M
C P X C
P P P
CL P
© X
=3 bf ft 3
P C EP
•H
P
P P
P P
O P
© cm ©
© ©
c ©
© -H 3 ©
bO-H bf
OT bf
•H OT
P P ' r ~3 P
02 ft
o ft
O 02 •
rq
2
hX Ji
»h rH • CV <—i hH i
hiz,hhKhhok rq •
02(^0202^020202^
_ Q Eh IK Q 2 02 ft-2 Qd <
QNCqq^WQZEH^OTSCH uj|
►HXCO^lcOrO^HCOO2'-0^Q2 bf
ft o U. O
ft. [Il U. Ul
'f
• CP»h»-(OOwHOOOOO «J
ICV1Cn-,h(VJMC^ 0(\J40CM jF
oq&.n r>4 mco •< cq cq £ *2
C^O-C^-COCOCOCOCOCOCOCOCO^^X,
nr'nnnnnrMnnnr
Dear Jim, Received: 78 April 10
A printer in a nearby town lost his sight a year ago. I have
been asked to take a preliminary look at hardware and soft¬
ware that might help him maintain a useful role in his business.
He is undergoing the usual training. His partner values his
judgement and knowledge but he is restricted in access for the
data on which to act.
My initial reaction is that a small data-base system with
audio response would be a good place to start. An audio
response type-writer keyboard should be feasible for input
although audio input is the ideal. I have looked over your
articles in Dr. Dobb’s and am hoping you might be able to
supply an update. I know there are groups working in this area
but lack references.
Fortunately, some financial resources are available. If a
suitable proposal can be assembled, I feel there is a good
chance for Department of Rehabilitation assistance. This is,
of course, speculative until we can get an initial reaction.
I have written Lloyd Rice from Computalker and will
send out inquiries as I run across references. Any information
you can pass along will be appreciated.
Sincerely,
James E. Tarvid Dellwood,WI 53927
Systems Consultants, Inc. (608) 339-7259
Any readers who may be able to help out are urged to
make contact. -TRW
TJ
o
o
s
q
bD
o
o
©
OT
X
X
•H
P
c o
p
p
P
c
o c
C ©
bf
©
©
©
CO P
3 3
C
«m
P
E
X
x C
P
O C
© ©
O
P ©
©
P
© © p
©
q
Cm -H
q © p ot
© E
©
P
P
©
bf
3 q .h © tj
© ^
E rH
P ©
E P
q
X ©
C
OOP ©
o
3 0-
© P
bf £
© ©
© O
© >
•H
O X P >» OT
C TJ
TJ ©
© <SJ
P E
* O
X X bf OT
P rH
© H
P P
OT E
>j ©
ft p
c
x © © q ©
TJ © rH
© 02
© X o
3 OT
©
X P
bf o
q ©
•H
P P Cvo O P ft
X
C p
E P
©
C bf
o © P
bf
© bf- VArH C
•H
E C
O P
rt ©
P P
•H
p o q
©
p q © © cm © p
>>
3 -H
rH X ©
OT X
P P P
OT OT
X X
w ©
X
> 1 © JX o e c
> tj r q .h
>2
C
P X
©
bD q ot
©
p q
4 P
X rH P © O bi) OT
ft
p
©
P -H P
x q
o ©
rH TJ
o ©
X OT
©
- C P © -rH
© 5
o
P E TJ
q
X ©
X
P © rH P O OT
© X cd P P
E
c ©
5 OT
©
P. © -H
© rH
p
E q x
p
X X © O bf OT S
•H OT
©POT
OT X
P rH
X ©
O © P
© P 3 Cm P © 'q
° . -E 1 S
o
rH
C .H ©
P P
p >
©
p *
p
q cr © -h x s-
.. >?<» W tj -
TJ
rH
c
•H P >
X P
P A2 X
X © rH > P o
bfiH C © ©
© q
© ©
© ©
O P
p ©
O -H
Cm
© P X - - .H
X ©
E C
© P
P OT
bf
CA © O
X -H © © © ft
TJ
p
P © -H
© *H
> TJ OT
©
- P
X X
bp
vSl,v*>3ai
g ot bf ©x
©
P.
P E
•H P
4 rH
4 O
P
c
- q © p
COT© Q.O.
rH
p- c
P* E 5
X
X Cm
O © rH
•H
ft© >)©<mX © 3
•HO 3 ©
©
3 -H
3 0©
P X X
© Cm
©
II
X
bf P. P © j
> O
1—1
o C
OT ©
>
P X
O' O
P P -H
O
© X © © »H
P X
y m x >
02
M
X
O © bf
C p
X OT
P *
P
.x ftp pp J bC©
X • © o - Cm
OT
O TJ
OTJCh
© P o
p x q
•H
X P
p P .H © -H
P C
•H rH
•h q .h
X -H be
TJ OT P -H
O «M
«m
3 O rH
©
•HOCMq©CMO©
P. O
p. ©
p 5
C © X
Q. o
•H
OT Cm X
OT
ft O -H -H P -H ot E
X
^ c S Q
Q
X
O >>
o
ft
ft ft
© KH
H
o
© © q
o
O
o n
P © X
rP
o
X x © ©
rH
©
33
OT X OT <
c
rH
p p p
z
VA
X
ft
© P >
CO
-4 >
«
>>TJ
M
•
cq ^ 2
CJ c^-X- Z 4 O Cb
02 rH -4" 02 rH 22
On CO X
TJ Cm X C
(M O 4 O' <
4 4 4 rH
c
4 2 - HH
p *
® 02 02 l-H O'. 02 02
02 X ^ Q2 H
X X o
© O .H
X X X X S
X X X X
©
X P X
o
(P'XQxxxsxxsir/j
OT P
OP pi.
02
Q
02 Q P
© P © P
X
X
X X X Eh
c
. b r? o s E c
3 O Eh
Q Eh 22 Q ^ S
Q E* X
© >1 rH -
QOhSNUUUW
© ©
ft ft 02 Eh ft O ft
« ^ Jon-
IPtfl
»H CO
h v—i o cn
HOT©
P X c
HQtnuCPQQQW
5 E
PZNZWSZQ22K
© TJ
©
ftp
•H *H
O ©
O P
ft
o-x: ©
X rH p ©
rH OT
O
p >
rH
o
C
bf rH
rH
? X P. -
c ©
z
P rH
•«H *rH
<
• c
P ©
t-H
* P
o
C o C +
O *rl
tn
H C
•H c c
O
O
p p
o
<M M
P
m 6 M
-4
r>
Ml
VA
© c
•h 4 h O
O
M
xoow
Q
O
x ©
P O.P.Q2
P E
P P »A-4 O O
CT)h44h'A
ONOC tH
<VJ O 4 OnvO 4 4 4 rH
bf
*2 P NDOWfi n
vr< on cq vc Q O
(VI PO
P O' (VJ «M
(M&, AQ6ri,(L,6,H
c ©
COQO WhQOINJQOO
X
vr co <( rn o
n cq
[t.Oh N
-4 vavt
coO'Cmouci.OH
4 VAvO CO O' O Q ft O
C~\ fA (A (A fA
rvrN-4 -4 -4
4 4-4
4444444VAVA
VA VA VA VA VA VA VA VA VO VO VT>
AArvAr'A
pn aaapn
AAA
AAAAAAAAA
* *
♦» >>
c a
OT «H
E Q>
© X
P P
bf
o o
P P
a
OT
© o
> ft
© o
02
X
C -
3 P
O C
<M 0)
E
a) bf
> ®
© OT
X
a>
© X
? p
o cq Q
CP EH P
&■ < 2
•oo a o m
ov(\hm4hcdq;Ehhc
02 02 02 02 02 02^X302 022
9 02 CP Eh Q ft O
^2D^ r -qqNQ2;2
c/n-Hc/Jcoc/jrHcn.HocQ
o ©
ftp
>>
OT X
•H
X -P
P OT
p
-P -H
< «M
X P
X
X
© c
P -H
rt <m
Xo
3 bf
IX
o
z
rH NH
2 02 02 02 2
at
E
q Eh q Eh Q C-h 02
H OT H OT H OT P
O
Q
ON(\JCN4rHOOCOvOrH < CM
(\ir'Wmr>HvooNQo
'Avf) NCOCb-<Q WOhCJ
vOvO'OvO'TvOVvf C^C^-C^
f r M T >r>r\f r \r>r»r\r\r>r\
4 vavo c^co <
c^-r-
(A r> ca ca (A ca ca
Number 26 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 33
272
A TINY BASIC
EXTENSIONS PACKAGE
BY LEOR ZOLMAN
362 Memorial Dr.
Cambridge, MA 02139
After getting Li Chen Wang’s Tiny Basic up and running
about six months ago, from the version published in Dr.
Dobb’s Journal , I knew I had finally found what I had been
searching for ever since first getting my IMSAI up: a well
structured and documented Tiny Basic interpreter which could
easily be modified to let me do my own thing. Thanks to Dr.
Wang’s consideration for the needs of his Basic’s users, there
was ample space available in the command and function tables
to implement the extensions presented here.
The routines fall into three independent catagories: cassette
tape I/O, video I/O for the Processor Technology VDM board,
and a set of four routines to perform IN, OUT, PEEK, and
POKE ala MITS Basic. The cassette routines are intended for
use with a Tarbell Cassette Interface, but shouldn’t be too
difficult to adapt to any serial storage device with a little
rewriting.
The listings are presented in a “pseudo assembled” form as
opposed to an absolute form for two reasons’
1. Since there are two versions of Tiny Basic available
the one from Dr. Dobb’s and one published in
Interface Age more recently, the absolute addresses
intended for one of the versions wouldn’t necessarily
work for the other.
2. Many of you have undoubtedly implemented some
extra features of your own already (into the Dr.
Dobb’s version) and would need to relocate addition-
al routines into higher memory anyway.
My own particular configuration, for those of you with the
Dr. Dobb’s version who may be interested, is as follows:
I used the free space from 074F to 07FF for my VDM
routine (I call it ZVDM) and a TTY output routine (ZTTY).
The latter was an overflow from the OUTC section, where I
didn’t have enough room to check for the TTY output switch,
output to the TTY, and output to the VDM. This problem
doesn’t occur if you use Dr. Wang’s own VDM driver, pub¬
lished in a subsequent issue of Dr. Dobb’s, but I preferred to
use my own VDM driver due to some of its special features.
Since the ZVDM and ZTTY used up all the space alloted
for customized routines, I simply changed the several locations
which specify TXTBGN (address of the start of the text save
area). Then, each time more routines need inserting, all that
needs to be changed are those same locations. They are, by the
way:
For the Dr. Dobb’s version: 022A-B, 0237-8, 061A-B
For the Interface Age version: 0136-7, 0145-5,053E-F
(in low order first, high order last format)
These three locations are within Basic as it stands now.
There are also three such locations within the cassette tape
I/O routines to follow—two in ‘SAVE,’ and one in ‘CHAIN,’
making a total of six location-pairs that need modifying when¬
ever the starting location of the text-save area is changed. If
the idea seems a little troublesome, then you can always cheat
and pull a little trick: change 5 of the six LXI instructions into
LHLD instructions which reference the operand of the one
remaining LXI instruction. Then only that one LXI instruction
would ever need changing, instead of six!
By “semi-assembled” form I meant that all opcodes are
defined for you, but you must fill in the operands of JMP,
CALL, etc., instructions yourself. Once you have decided
where the routines are to reside (they may all be put into a
single continuous block-probablly the best way to do it),
then you fill in an address to the left of each line, correspond¬
ing to where the first byte (out of a possible 1,2, or 3) or the
instruction will reside. It may be desireable to leave NOFs
between routines, just in case you ever desire to add bits and
bytes to the code. Also, this padding may save a lot of sweat
should you miscount the addresses and need to insert bytes
afterward.
When finished, you’ll have an exact image of the code,
tailored for your software configuration, and it can be hex-
loaded (or toggled, if you haven’t yet written or acquired a
hex-loader) right into where you want it.
Page 34
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
273
The last chore that needs doing is to add the commands
and functions to the appropriate tables. If you’re using the
Dr.Dobb’s version, you simply insert the ascii string for the
commands and functions, together with a two byte address of
their first location (in HI-LO order, not the 8080-normal
LO-HI) whose most significant bit has been set to one, in the
appropriate tables. You may call the commands whatever you
desire, but shortening the names (say, from SAVE, LOAD,
CHAIN, and NAME to SV, LD, CHN, and NM) would leave
more room in the tables for other things. I ended up running
out of room for commands, so I took out some of the padding
following the function table and transferred it to within the
command table, shifting the function table starting address to
higher memory in the process. The only reference to the func¬
tion table is at location 04E7-04E8 (Dr. Dobb’s version)
which should be set to the new address of the first byte of the
function table minus one. The instruction is the one at label
EXPR4. This procedure is only necessary if you need more
space in the command table, and happen to have plenty of
extra space in the function table. If you are running the
Interface Age version of Basic, then you must shift the entire
command and function tables from their present locations to a
free location, leaving plenty of space between the two tables.
In that case, there are a few instructions referring to TAB1,
TAB2, and TAB4 which will need modification. When that is
accomplished, set TXTBGN (in all the places it needs setting)
to the first free byte of text area. Some of the routines
presented here may be inserted into the space vacated by the
command and function tables, so that it won’t be a waste of
space. When all the tables and routines are intact, you’re up
and running!
Tape I/O
Four commands have been written to handle the naming,
saving and loading of programs, utilizing the Tarbell Cassette
Interface. The commands all center around a ten-character
program name, stored in a special buffer in memory called the
“name register.” Whenever you save a program on tape, the
dump is preceded by this ten character name. When loading
from tape, you tell the machine to search for a particular pro¬
gram by inserting that program’s name into the name register,
and then executing the LOAD command. Basic will then pro¬
ceed to compare the name register’s contents to whatever
comes in from tape, until a match is found. The restrictions on
a program name are as follows:
1. It cannot exceed 10 characters in length. Leading
blanks are ignored when setting the name, but any
blank following the first non-blank character
become a part of the name.
2. It cannot begin with a *?’. Any other non-blank
character (except, of course. Basic’s input routine
control characters and some VDM controls) are legal,
including most control characters. These, in fact, pro¬
vide an elegant method of ‘protection’ of programs
from unauthorized use, since no one can see the
printout of the program name.
Examples: “ NAME1” equivalent to “NAME1”
“NAME 1 ” is not equivaltne to “NAME1 ”
“7ABLE” is illegal; “?” not allowed as first character.
“THIS IS A TEST” gets truncated to “THIS IS A”
If you enter less than 10 characters, blanks will always be
padded in on the right for you. If you want the current
program name to be printed following every RUN and LIST
command, and for it to be cleared (to all blanks) following
every execution of the NEW command, then change the
following 3 sections within Basic:
addr. in Dr. Dobb’s
version
0233-0234-0235
0267-0268-0269
0226-0227-0228
addr. in I. A.
version
0141-0142-0143
0175-0176-0177
0132-0133-0134
change to
this
CALL RNAME
CALL LNAME
CALL NNAME
Command Syntaxes and Operation
1. NAME command
syntax:
NAME (name) return
or
NAME? return
Sets the name register to the given name, where (name)
follows the rules for a program name given above.
Examples:
NAME WIMPY return (OK)
NAME WIMPY return (same as above)
NAME A BIG DEAL return (OK)
NAME YOUR PRICE! r eturn (exclamation point
is lost)
Typing NAME? return causes Basic to respond with the name
currently occupying the name register.
2. LOAD command
syntax:
LOAD (name) return
or
LOAD return
Loads a program from cassette tape. If the name is not speci¬
fied, Basic assumes that you are looking for the program
whose name is currently occupying the name register. If a
name is specified, then Basic first replaces the contents of the
name register with the given name, and then searches for it on
the tape.
There is no need to set the tape player running in any
particular place before the command is typed. In fact, you’ll
find it easier to first type the command, then hit return, and
only then set the tape going. The tape may be started
anywhere, and Basic will skip through any random programs
that may pass by before the one named in the name register.
Of course, if you know where a program is located on the
tape, it would speed things up to set the tape going just before
that point.
Number 26
274
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 35
w
The LOAD command executes an automatic NEW before
searching, so that the program will always get loaded at the
start of text memory. The program resident before LOAD was
typed goes into oblivion, of course. If you wish to append a
routine from tape onto the tail end of the program currently
active, see the CHAIN command.
PROGRAM LOADED
OK
gets printed. If the program does not load correctly, you will
be treated to the message:
CHECKSUM ERROR; RELOAD
OK
whereupon you may try it again. Note that all you need to
type the second time is:
LOAD return
because the name has already been “registered” from the first
attempt. Should you repeatedly get checksum errors, or no
response at all, then try adjusting your Tarbell or your player
as per the Tarbell manual.
For IMSAI owners, there is a special added bonus. Whatever
the input routine sees on tape is echoed to the programmed
output leds on your front panel, so that by watching the
behaviour of the leds, you can tell whether a program has been
found yet and is in the process of loading, or if it has not been
found yet. You can also tell whether the Tarbell has lost a bit:
Since bit 7 is usually set to 0 in ASCII, then programmed
output bit 7 should stay pretty solidly lit (reverse IMSAI logic)
during the load process. If this doesn’t happen, then one of the
other bits will appear steady and you can bet that the interface
has dropped a bit or two.
Typing a control C at any time during a load will terminate
it and restart Basic.
Examples:
LOAD JOHN return
NAME HORSES
LOAD return
LOADED DICE return
(OK)
(this combination will
search for HORSES)
(will search for a program
called “ED DICE”)
3. SAVE command
syntax:
SAVE (name) return
or
SAVE return
Saves a program on tape. If the name is omitted, Basic uses the
name currently in the name register. Specifying the name
alters the name register and then performs the save under the
new name. After hitting return, Basic will say:
HIT RETURN WHEN READY:
whereupon you position the tape to the desired point, hit
record, and hit return when ready to save. Basic will prompt
OK when finished. Control C aborts the save.
Examples:
SAVE THIS MESS return
SAVE THE TIGER return
etc.
(names the current
program “THIS MESS”
and saves it)
(names the program
“THE TIGER” and saves)
4. CHAIN command
syntax:
CHAIN (name) return
or
CHAIN return
Loads the program into memory following the last byte of the
program currently in activity. The command is identical to
LOAD, except that the automatic NEW is suppressed. It is use¬
ful for loading common subroutines.
Restriction: the lowest numbered statement of the CHAINed
program must be greater than the highest numbered line of the
program currently in memory. Exceptions to this will give
Basic (and its users) headaches in text editing.
Example:
CHAIN RULE return (loads a program named
“RULE” onto the end of
the program currently in
memory, and also changes
the name register to
“RULE”. If this is not
desired, you can change
the program name back to
what it was with the
NAME command.)
That’s it for the tape I/O routines. May you never need to
key in a Basic program twice again.
Special Functions
This section consists of two functions and two commands,
all based on their MITS 8K Basic pseudo-counterparts (mean¬
ing that they work toward the same ends, but do it different¬
ly).
1. PEEK function
syntax:
PEEK (expr.)
This function returns a value from 0 to 255 corresponding to
the data stored in the memory address specified by the argu¬
ment expression. In order to PEEK at any address in the
8080’s address space,
a. Take the decimal value of the address you want
(0-65535).
b. If it is less than or equal to 32767, leave it alone.
If it is greater than 32767, then subtract it from
65535, add one, and negate that result.
c. The result from step b. is the argument to use with
the PEEK function.
Example:
to set the variable X to the contents of location 0D97.
a. 0D97 is 3479 decimal (7 plus 9*16 plus 13*256)
b. 3479 is less than 32767; leave it alone
c. X = PEEK (3479) performs the assignment.
Another example:
to see location CC00:
a. CC00 is 52224 in decimal.
b. (65535-52224) is equal to 13311; 13311 plus 1 is
13312; negative of that is — 13312.
c. PRINT PEEK (—13312) displays the location’s
contents.
Page 36
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
275
The strange values which result for addresses greater than
32767 are a result of two’s complement 16-bit values being
used by Basic.
2. IN function
syntax:
IN (expr.)
This function returns whatever happens to be present at the
input port whose number is specified by the low-order byte of
the 16-bit binary equivalent of the given decimal expression.
In other words, you give it a value from 0 to 255, and it comes
back with the data at that input port.
Example: to set M equal to the data on the sense switches:
M = IN (255); REM 255 IS THE SENSE SWITCH
INPUT PORT
3. POKE command
syntax:
POKE expr. return
This command presupposes that you have set the variable P
equal to a value between 0 and 255. It then deposits that value
at the memory address specified by the expression. To
compute the decimal equivalent of a given memory location,
use the procedure outlined in the PEEK function description.
Example: fill the VDM memory with ASCII blanks (VDM
memory is located at address CCOO):
10 P = 32; REM 32 IS AN ASCII SPACE
20 FOR I = -13312 TO -12289; REM VDM RANGE
(CC00-CFFF)
30 POKE I ; REM POKES VALUE OF P AT LOCA¬
TION I
40 NEXT I
4. OUT command
syntax:
OUT expr. return
This command outputs the value of variable D to the output
port specified in “expr.”
Example:
Turn on all the programmed output leds on an IMSAI:
10 D = 0; REM A = 0 TURNS LEDS ON
20 OUT 255; REM LEDS ARE AT OUTPUT
PORT FF.
NOTE: For the commands POKE and OUT, only the low
order 8 bits of variables P and D, respectively, are used. Thus,
if P or D were equal to 3, they would have the same effect in
POKE or OUT as they would with the values 259, 515, 771,
8963, etc.
VDM I/O
The program I call “ZVDM” is a “character output to
video” routine using Processor Technology’s VDM-1 video
interface board. The program will reside at location 074F, for
those of you with the Dr. Dobb’s version of Tiny Basic, and
there is ample room between the end of it and location 0800
to insert the ZTTY routine to accommodate both a TTY (via
the ZTTY routine) and the VDM. This is a general purpose
routine; it will run with anything that supplies it with a charac¬
ter in A and a stack in SP.
ZVDM is a scroll-based video driver. The cursor originates
at the bottom left of the screen, scans across for a printed line,
and returns to the beginning while everything scrolls up one
line. When given continuous data (a listing, or extremely
wordy run), scrolling is held to a maximum of about 4 lines
per second, utilizing the VDM on-board one-shot timer.
The output rate may be increased to full speed by typing
the F key during output, or may be halted momentarily by
typing the space bar. If the keyboard you are using happens to
latch its data, then typing any other character (after you have
sped up the display with F or stopped it with a space bar)
resumes the normal 4 lines/second rate. If your keyboard is
not latched, then simply letting go of the special key (F or
space) returns to the normal speed.
There are two other special VDM control characters: When¬
ever a control Z is received, ZVDM will clear the screen and
restart Basic. Typing a control V shifts the effective bottom of
the screen up by one line. Since implementing this feature,
though, I cannot say honestly that I have found any practical
use for it.
Carriage return and linefeed characters (CR and LF)
function just as if the VDM were a teletype, except that you
shouldn’t linefeed from anywhere except column one. Violat¬
ing this may cause your cursor and subsequent text to be
invisible, since I use VDM hardware blanking to curtain off the
portion of every line following a CR.
When ZVDM receives a backarrow (ASCII 5F, or under¬
score), it physically backspaces on the screen, wiping out the
previous character. If the Basic you are using currently inter¬
prets mb-outs as character deletes, or any other special char¬
acter for that function, then I suggest that you change it to
recognize 5F’s for that purpose. Then, change the “print”
handling routines to recognize, say, a $ for the linefeed
suppression character within a print statement. Another
feature of ZVDM is automatic wraparound. You may print
many continuous lines without a carriage return, without any
ill effects.
Following the ZVDM listing is my rewrite of the OUTC
routine. Simply deposit it over the existing OUTC routine,
and then insert ZVDM and ZTTY wherever you want them to
go, inserting their address at the appropriate CALLS in OUTC.
When running, control 0 should still turn teletype output
on and off, but VDM output should never be affected. VDM
dip-switch options should be set to: cursor on, blanking
enabled, and control characters blanked. The other options
are, well, optional.
Last and least, you’ll probably need to hit a control Z
immediately after starting up Basic, in order to clear all the
garbage out of the VDM memory, and initialize the scroll
control port. The listings to all the described routines follow.
HAVE FUN!!
Number 26
276
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 37
CHAIN" AND "LOAD" ROUTINES
03 C
tuj
p
p
QJ
Ih
C 03
rH
c
>>
Q)
X
r-r
QJ
aj
c
P
C TJ O
•
X
X
^ QJ
d
CO rH
0 ) C
E
03
p
X P
C/ -H
•rH I-H
P 3 P
03
P
0
s c
p d
tiD 0 )
O O X
e
c
R *H
•H T 3
Q> XI
03 X QJ
. HO
E
d
0
X
e e
C c
p 0
O >>
QJ X
O M
d
d qj
CO C
U P
p
X
PC <
(U Eh
X 5 X ••
03 X
«M O- to
•H
QJ
O
C w
E
e o ox
rH
to d
c 0
d X • s
•
03 E
Q> * Q) P
QJ
E
E C C
QJ
qj d d
a>
rH
PH+JH
c
c o
> P to X HO
QJ X
3
3 3
>
C O X 10
c
O
c c
Q> .
Sh
O X O O C
P P
E to P
CO O 0 )
•H
•rH --- CO CO
•H
c
0 Q) O C
> p
X X
QJ QJ
>» E
3 >: C
.* X
MP QJ
P
P to
X U X 0
&
X
•H .H rH
o
P C CO O rH
X QJ 3
to 0 3
0 X
3 O QJ O
3
E O
M
HO rH
a>
•
C d HO
C CO
qj 0 u
O’ Q) OP
0
OH Q) 0
O
0 +j
•h E d to
D
<
(0 QJ
CO P o-
03 >> 5 E «> •
X QIJC
0 X O Q)
QJ X P -
p
C to C 3
e
0 d
C P T)
Eh
X
W 10 X
co ;>> oj p e « d p p
HOX O Q)
aj 0 P
code
d x to
p
O QJ d QJ
X
0
•H QJ J-,
0 ) X
5
CO P P X C >1 CO
H J QJP
X PC
O E O •
e
E X
E
c to
c E n x
Eh
o d
(4
d
•H 0 HOX C X X >)p
O 5 C-H
TJ P *3 >1 QJ
QJ £ QJ
0)
0
0
d
0 ) O Eh
TD P
c
- - O -H
CO 0 X ‘H
0)0)0
QJ P P
CO
P P QJ 0
p
X rH X CO iH O
P
T 3 QJ
P CO to -H C S to
•H
O C E X
QJ
- CO
3
CO U c C
CO
rH X rH P
QJ
0
*a d p,p
d HOX
O QJ -H O X O
p 03 QJ P QJ
£
0 d
>> d 3
>: qj
0 X. Q)
CO
T 3
C qj
0
C >> C r - •
CO QJ C
QJ U X
• to to C rH
CO P Qj 0
to
0 X
0X0
QJ
P CO
p
p
• P
•HCOPOX>OEQJ
CO 0 )
rH
to > c
QJ J-r T> QJ C X
c
•a
to <m a>
a>
(0 <hIh£<h 0)
H 0 ) Q) H T 3 0 lQ )3 C
QJ O X QJ
QJ PQ QJ d C
PQ
X 03
C x d 0
c
C *H C
HO
E
•H -H 0 *H HO
P Wi W) CO
03 CO X X 03
>»TJ -H X
p
Eh C CO 03
Eh
O Eh
d 0 EH QJ
d
w
fe
CD X
CD
X
CD
X
(\f
Eh X m
Eh
CQ
s
w
<
D
Eh
Uj X Eh
or.
Eh X X
5 °.
? e
Q to PQ pQ
Eh «
W PQ [fi
Eh EhCO
Eh
X
X Eh W
< rH
X X
X O X < X
< X O X <
A
D
Q X N 3
CC X to
X
O
X
X X <
X Q X -to
IH Q J H »HH
•Eh -h -
O M
X Eh -
X
V.
0 Z X
Eh X
P O CD <VQ X
£ to X O to _ w _
Q m S
B
B
D
H
A
E
x m u: a
<
O Q <
O
W H H Ci, Cl
X
O
X
X r —1
Q Q
Q 0
X a
X
X vO
VO
a
*~H X to
mxhmP>P>PhJ>C>xX>
<
CO Q X H<Jfn
H10 fH fH
M x X
o x x > b
X < s
ZXXX< 0 < 0 X>< 0 Q 0 uX 0 X
2 <SNXCC<WlXr
< is) < X X X X b r X
X X s
•H 00 S 0 »HU 0 '- 3 »hu , - 3 US 0 SQS 0 S<SQ>hS 0
^UU^QXUXCOQXOXU'H
<bHOir
X(/lb
X
to
to
Q
O
;£
Q
<
O
X
I I
I [WO I &H Ito
K> P to
WW4W^HQWc\jr>Wt\jQWQN<vOQNON«r><r\(MacO<HWQNNHfeQNQQ\ONCQ f^O
W WO r°»Q NOfflONWOO^O'ANOO tN-CO 4 HN NW O OCQ OH < O O N H <UOOXWoQQO
g
QJ
X
0 )
H
£
X
03
5
X
p
p
QJ X
E
c
Q>
P CD
0
3
o
C" P
tJO
p
E O CO
V—
p
tj d
d o:
d
X Eh
3 .*
c
0 )
CO Q) QJ P
Q)
QJ
QJ
X
X
toP 10 H O
a
o
•H P
(0 C C >)
P
E
e
P Eh
p
Q X >; O Q)
CO
•H
X
X -H
Q) H H X
>r
d
d
CO 1
HO
QJ 0 C EX
CO
o-
•H
E P P
X
C
d X
c
C P QJ P 3 0
o
d
co a>
d c
O P
3 3 P
p
rH S
QJ
•H X C Q> CO P
QJ
«
3 P
P o
QJ C
X 0 O U
0
E
X
. O
rH
XOOPQJ^JCC
X
P -H
d Q
X QJ
QJ 0 e Ih d
c
d
QJ
X EH
■HO O >> X O QJ Q> 3
o
P
qj d e
T 3
CO CO
W) P
>-r
U
P
to O X
aj
•H Q> XdQJCPO
c
p p 5
o
c
d U E E to
CO
HD
P
Q Eh
X
pnc px Coe-
QJ
d
>> co
p p
QJ -rH
CO d Q) 0 )
O
X -H
•c
p
XC*HOd OQ)-H TJ
>
P X o
Q)
E
CO X P P rH
rH
U
O
C T 3 QJ
QJ d rH X P C > 0 X 0 )
d
03
rH P
HOP
d •
QJ O CO CO rH
r —1
X
QJ
•HT 3 P
p
ojpd doodXEX
to
0 )
d rH
•H
VA C O
E >; >> QJ
QJ
• P
d 3
3
x m *h >: n p co 3 to
u
QJ >>
•
CO
P to CO X
X
QJ
e d
Qj — X
X
P O QJ XX -rH
a> X 3
X Qj
P 5
p co e
u
>
•a ho
> P E
P
r 0 p.HQ)P>'OTJE • C
co
T3
> U d
d >
CO QJ X
qj d x ffl d
d
d
T 3 QJ
d qj 0
3
CQJCXQ)d 3 C 3 QJ-H
aj
c
d d Q)
QJ «H
C C-H
ttfrH Eh Eh Eh
Eh
CO
d c
co HD 0
O
d HO’H o H 0 CO d dXTJX
d
CO EH C
>j HO
X Q 2 -
POOQ
cd to b X
HQO J
CD 2
Eh ►h
- C/J X
•• Eh Eh O
• cc w no w
•toCD -O *
< < <
X X X
H JJH.J H
><<><>
S O CJ s o s
w
H
s s
O to
CD
PQ
6h
S X
•Q O
< Eh X
„ w q a - -
Q Q O ^ X <
X X J
< x
x <
B S
JOIO
•o *o
< x Q < :
O X X o ►
X
Eh
X
■ 6h
Q X <
CD X X X CD
><>><>1 JP><>hJ>hJXH
^ — 00SI0UX<X0<0<
. ' - SOSO
H Nj . ^
XXXOs = i‘--»'-'S. , -JOit«a.
UhP^OSSUKXPQ
Eh X Eh Eh
X X b b ^ X
Eh O O S O < Q to ® O co O IS
- - Uj * O * * £ • O X Oh4(/} W
xm < mfflxQ<wQ< o wnoX'O
' X X xo
SHQSObSOKWH<bXOK
X X CD X X *
g >P>JXHHP>JQ>X>s'><M> >
o<o<ux><0<Q0X00XX0<
HHSOSOXQSOSO<S'-HQSO'- 3Sc
X
§
O X
o o
0)
TJ
o
c
to O I to
vO CM I VO
pj toW-3'rHWQQWQWQrH<Qmtoc\J.HQtotoOtoC^-Cq<0'< v '\QQoQeQ »-»'0 q WQOr-n«<nNC0QNVVll'0NHr\O
ol WWOHnoononOHHOHWONNWVONN'OrdNHNNONOWwOUNOCO^tNJHNCqoNOOWQWOWQO
Page 38
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
277
e o
E p c /3
0 ) Cl) C <
P E 3
to rt o p
>> E o E
tO 0
p p to
m a) «j c
Eh t*0 CD -H
to £ 0 )
3 0 0 0 C
E p E 0 -h
x 0 p p
H£H W-H 3
(0 JH-H O
O rt C E I
0 O X -rH i
to .o S x Eh
•H 0) < P GQ I
X O £ 2 -H h
P P
a-H ^
O (O+^XU
0 ) (h (DO
P E Eh O
< X
X E 4* •'
c a o
3 ttJ
*Xp .O
0 c
> -H P
rt Ed)
to a, no
1/3 >H X * X
t/J 55
HKX X H
X • O < <
X <
z
z
»-3
Ub.QQp 200
Z[qw[i]gx 04
B§
X
Z 2
Q
Eh Z
H JEW - - -
P -
X <
X Q w X
HX 4 < xmsmxos
£h X
Q X
X X < X X
X O
XXX X
OhOJ jHHH
XXNHh
O O
to t /3 X X X X Eh
X c /3 O < X > >
O z z > x
X X
2 D < O O < [il
h t/j O^SS
PHbSX
X
X X O X X 0 x
HOHK
X w w
W X rt Eh •• (NJ
Eh
X w
Cx 3 X
Z W 1/3 w w
•«
z Eh
W
§
X Eh
|
X < z w z z
X
X S
Eh ZZ X Z Z
0
Eh O
X
* * * *
* *
E
E 0
O
O >
•H
•H O
P
P X
O
0 rt
3
3
E
E <
X*
P
P Eh
X
to
t 0 C /3
E
E
E
•H
•H >3
•H
X
Eh
z
=*h
3 >
M P
O
<
0
P
X to
E
X
E
O
O
O P
•H
0
0
T 3
X
E
Q
0
e
E
X E
tj rt
E .*
0
•rH
e rt
■P
E P
0
•rH 0
X
P
rt e
0
rt to
r-H
P 0
3
E 0
HD
E E
X
P
3 tO
0
O
0 X
0 O
rt
•H
O
HO
E
(X OX—'
X O
•H
E 0
O
O'—X X
0
O
E <
P
5
P T 3
z z
a: x
< P Eh < O
X -< - *
<Q XJI
P X
P > < > X Eh
<O^ZO>W
O 2 03 X S 2 OS
3 e to rt x :
o *h a> >> > o t
E a to
P E P 't
PQ a> O PQ 0) s
Eh MX Eh M l
Z
X °
•f CQ
Eh a:
a. <co
P Eh > O <2
- P - • » • >
<OX(OJtJ< >
(X
0 ,><hhQ>>p
XO^X>QOO.
WSi/) Js<?»sc
E E , E
0) -p -p .h P rt
P rt 3 X
to X XP
>> ? *H
< 2 < <
<P <X
^ggsga
OSSXSK
rt x> td -a
to -h rt o n
03 E *H -P 03 rt
0 rt 0 E E X
E > 3 rt -h -p X
-T3 P X > a
tJ-H e rt a. rt
rt 0 > x P
0 P O <
p > to p p ;
0 rt >» 0 0 <
M to to M bO (
x < p p < x :
x x
XC/3XhHQ>>XP
xz>x:>qoooc
xxP5<ssx;
Eh
X
X
fxj
Eh
w
X
X
w
0
0
X
X
QrHvovo w^r^CNJ^O On
o rt o no (\3 o no
vp,\t\Q HrlQ^
W Q U Q fil u O
O Q 04 PQ CE'O ON
O rtt^Q'O f\J O
^QfVJHtillAlL, Wr\N
Q C^.r^r>»r>cONO S- Q X
Q WEENOv
O C^-NO < NO O
EiAH WiAEWHNrt
Q W (NJ f^QO no C''- X X
0
X
t/ 3 —*
o-
E
2
•H 3
0
O
^3
O
E
E
t,.
£ E E E
w
ro
C 3
0
5
E
O 0 0
X
E
Z X
Z
E
0
O
X E P X
O
E
P to
f-H O
O
ra
E
< O 10 X
0
E
E 0
X
X M
E
P
^ P -rH 3
E
P
O >,
£h X s c
Z X
P
c h
—'
.
10 HO X
. 0
E
P,
t/j O < •• X P
<
X P
E
E
E rt
X
X 0
0 >> 0
0 X
3
to
X
• Z X Ul <
O
x 0
rt
rt
0 P
£
X l-H
E t 0 \E 0
E P
O
E
rt *h
EH—'X P < O
X
X W
E
5
p to
• Eh t /3
rt _ E
O O
O
0
p
p
X 0 P < 2 X
X
hL
to 0
Q <
e m 0 -h
^ ^ c
P
rt p—'
P C Eh PI P PI
2 0 '
0 w
O O
p
•H E
E
< 0 m
Eh| E rH
E rt
TJ
O
x ox
Eh rt W X t/j X
< O
Eh
0 E Eh 0 0
to
HO
0 O
O Eh
0 y rt p
E 0
E
rt e
t -1
E 2
P>X ( 3 sC <
X *
s
E Xc /3 E E
3
0 T 3
ja'
X X
e/ e e e
3 E P
rt
E E
«
TJ *-3
P to < Z O —
O r
• <2
•H • Eh -H *H
E
E E
rt
X 0
1 3 O
P rt E
to
rt 3
E X
Z — Eh PI PI X
O P
r X
p tM X P P
rt
E P
-w
X X O E
0 0
E
X P
C 3 Eh
rt -he
< O X x X 0
X PI
z 0
, 30 X 33
0 +-» 0
0
W EH X
•hI OoX
E 0 t/j
0
0 0
X
O CN- O
x X i: O x
X P
P O
O O O
k- ^
E
J rt
2 t/. W
5 E
P
E
X 0
X C_> E^—-
X r :
s
X X
E to E E E
■H P
rt
0 p
< H P-.
c X* E* 0 E
0 -H
E
>t
0 p.
>S *H
M ..
r X
to O
•
E
E to
z 0 z
•h Z xi P rt
bo -
•H
E -
X
0 H£p
Eh W ••
E 0 X E E
P
XP
0
X f-n
rt x >>x
rt to *
O
rt to
<
OPE
C/J 2 x 04
2 X
0 E 00
O
3
rt E
* X 0
VT\
rH E rt x o,
•H 0 0
a
E 0
Z Eh
E 3 rt
X < Eh Eh
Eh
O O
PTJ<PP
E
• O
0 X
X rt
E >1 E
X
>>
0 c
E P EP
CJ Z 0 j t/^
CQ
X <
tO T 3 10 W
to
P T 3
X u
P
E 0 p p p
E
E
O
0 p
3 E to
men co
S 3
X w
>> rt E >> >>
X
0
0 E
X 2 Eh
to
O rH 0 0 0
rt x x
3
O X
OOO 0
X
to rt to to
•H
to rt
< X
E
O O HDHOHOO"H*HX
P -H
X P
>> O XJ E
X w
p 0
Q Z W
0 X
Ctl
0 x
« 0 rH x CQ
M Eh
X <
2
Eh O
Eh no 0 EH Eh
X fil
O
<
< X
W
0
X X W
CNI til
0 . X
X w
5
Eh
< Eh X
U . >h
«
§ ►-3 i -3
m C oM<h36hX1Eh
OXZXXCc/'jCcq
xoppxoxox
- < z <
X Z X O X <
XOOZ * - Q CJ
j.i^xm^. sx
§ H < XI H»—(< H > X X X N Eh
O X CO <X>QXN022asW
HUhO JS^UXShhQHjX
< X
• O
s x q m *o
PI X
X
X O 04
Eh
4
X
ws £
X O
CJ W
P"N
O W On NO X
X
H< X
5 6 * ,
X
X O O
PI 04-4 NA -4 ^
4
Z 0
2 pj x
eg eh
X
X
X P
Z Eh X
X N Eh
Z X Zt /3
< O 04 -4 O O
O
X XX
X Eh
CNJ \Ti 4 - 04 4 ^
4
X < X
• x O
Eh <
P
x 0 X X
O
Z O vr rH P X
O
i
Q <
x < d d 1
c n
X 04^-44 -4
04
00 p
x rx
XX <
X X < <
C 3
X
604 iAnava
P 04 NTN 4 VA 4
P
4
X O
Eh
P x 0 0
P
o o 'nrvj r^CNj
b, tNJ 4 VAVP\VA
EWrtHEQ C^-Q Cn»
U3XOXCOOOO
ewcQhvo < x cu r^- c'n rN c\j q,
Iilb,UO(MOrib,t)MNJHGUG
iq N O N
Q X O O
o o w n«
CNJ 04 4 4 ^
O -4 ^OVOiCVJ
04 vn 44 ^
O O'oo 00 X
04 4 4 -4 4
O CO C^-rxcsj Q
C\J -4 NTN4- VAO
II II
II II
Q rH X Q Q O'
OH «<000
Number 26
278
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
05
o a-
£ P
•H p
CO O
X
>3
. X X
05
P X) O
O 05 P
E VI O
>3 M 03
£ Cd
Ct P, O
P
p -n
- £ P
cop
CO CJ X
•H 05 P
10 3
P O
P 13 r
C 05
p x
05
P
O 05
E £
05 X
E
O X
CO O
p
p -p
H C
03 O
5 O
P
05
P C
o o to
>1 05
S cd-H p
X P
Q P p 05
£
> 0. *H P
r-H .M
X CO C/3
o o
O CJ O-H
• Pi X
P X UD
05 +J
Eh 05
E £ >»
P> P P
OOP
. -H O
X O O
P Cd CO 0)
E
•HP P P
O rH 05
p 0) P o
CiOrH F
05 X P O P
o
> P O CO
X p S
ro p p aj
£ O Q
CO O M P
cd CO >
X
Vi CQ S
Eh jE S CO Q ~i O
X ft, to3CO •>0', o
<co&,(\jo,>os x n: o x
s o 2= n o o
* * xcehxxxxeh
N2fcNO^P>IOOril(q-. ;
'-J H u b ft, u O S W O, P. K n 'Q
o 3
csi >
•• <
a-a-
^ s
n Q
> >
3 3
> >
Eh
o w
cd •
Xi
X
X Eh
>-t
P >3
05
(0
w
<
Eh
P -H P
05 A*
•H
o
W o
Eh
O 05 P
£ CO
X
CC X
S Cm > 05
£
p p
£ P
o w •
Eh X
o
Q cd P P
P o
P 05
X C/3 —' 2
O X
T3
> E <U P.-H
cd £
X XX
05 p
- o
X <
O rH
X X
•H P
X o
-PQ X 5H
X
O
O O CO CO
p
S °
P X
2 CQ X C/3
< X
tiO
P P 05 -H Cd
o
Cd-H -
P
•H O X X
o
£
CO x
< X CO CS3
'V -H
S Q < W
W >H
P X to 05
p p £
M) p cd
H £
O Q X >
o
£
05 W) O -H E
P -H
S m <H
•
3
s
1 X W • or
< w
o
p p to x cd
ox •
UP OP
O •
Q
X X CC W W
X cc
POO P CO
0)
> 05 x P
p
O -
>
X Q u
Vi W
(0
-Cd£-
p
X P P
cd
CS3
P .. M <
X
•H
£ P 05 0) X 05
o
CO X
CL, P -H C P P X
sojowon
*"3 O 05 >3-
bO CO P ■€*•
o C -H >5 -a:
p -h x p oj oj x
X -P 0)£HQ
T 3 -p > -p x
0) 05 05 05 E EH
M E C/5 05 03 2
C O 3 P P X Hf
03 CO 05 CO 05 cc
x o p £ X
OC+J'h'H P -
-P 03 E o
05 -H -P Hp bfl
P J CT1H c
03 05 05 *-H
>>T1 5 -P O -P
03 05 PH'H P
E co P a x to o
p o p -m ro aj
>3 to ? rQ x
O 05
05
i x> <M P C x
P P --H -P C
P P co 03 E
P CO O 03 O ►
to -h cq -h ;
C • <M
•H P O P -H J
05 -H c 'CJ H
O >03 03 O V
•h oJ 5 e :
Eh P CQ
W P P 0)
cc >
s c c o
05 Q -H OX)
X > Eh X Cd
Eh
05
Eh
X
w
w
W
3i
o
cd
£
O
X
«m
P P
o
>3 >
Q
p
£
w
D
X
w
X
X
X
X
05
•H
p
0>
P
05
o
p
05
W
£
>
05
o
X
O
w
Eh
X
CJ
Eh
W
o
o
P
P
P
X
cd cm
X
cd
p
£
X
O
Vh CO
(S3
X
•H
Q
cc
X
<
C/3
p
•H
P
CO
X
P <m
p
■
•H
A-
•H
O -
p
P
2
Q
<
X
X
X
2
X
•H
P
p
P
o
05
O
CO
CO O
>3
cd
p
O
P
O
CO
X
P
05
cd
<
X
Eh
<
cc
5—>
w
3
o
P
o H
p
P
3
cd
cd
X
P
cd
P
P
05 X
cd
W)
o
X
O
w
Mi
w
CO
£
X
E
3
P >2
E
XX
O
05
05
CO O
X
o
o
cc
w
Eh
Eh
W
p
P
>H
05
P CO
p
p
P
X
>
O Q
p
p
X
o
w
w
Q
M
X
Cm
<H
p
o
Eh
X
o cd
p
05
p
o
X
Eh,
X
X
o
M
X
w
•H
•H
o
£
Eh
p
>3 E
o
bO
o
bfl
Eh
P CO
O 05
co m
T5PH
05 P
CO P O
3 Cd 05
05 Cm
P H P
HOC)
Eh w w
cq >h w
w w w x
O CO X X Eh
< CQ O Eh
XI W O
ft, X W Eh Eh
W Q C/3 D
X Q O
< X CO
2 Eh -W
< W • CO
CJ X X CQ CQ
Eh O • X
S Eh 2
• Eh Q
5-H O 5-< X Q
Eh H X O <1
X CO X
o < X X w
X CQ W O X
CQ H £h
CO >h co
5-hX W X X ~
x 5 -h x w o x b o
EhEhEh>X Eh O X
**** + + + + *
X
g£
X X
<
5-3
5 X
g w
CQ
>h b x
Eh CQ O
Eh X
A3 -
O S
X g
6 h?>
O Eh W N
CO C/5
a -8<
X
CO < <
X Cl X
X 5-3 O
e -0 X
5-3
S XhJX
o < o
X X O x
X
o
HNHEH5
X X >■ X ?
0X202
o p c
• Eh O
P X 5 1
P O J
O (0 ^
X 0) to
X 05 i
03 P P I
T> P
03 C X
X
■ CHP
rHH 0J
1 X *H
IH^Pft!
: x >h .m x
5 -H Eh CN
5 Eh P O
CQ
I
j p • p c cd x
X O 0) *H O X
P + 0)>)>J-HCMN
3 -h x o cocdcdo
O ^ EH X X P p
>3 -H 0] O 05 ie - co
X
3 r co
X >H C/j X H
X X EH X X a
X Eh
M X EH X
X X iso O X S
h<h 3 xo ' : 5
>H
Eh
Eh
ICO X
IO X
ISc
< m .'<1 < x cj cam) c\j >—i»—i O' o o
uaxuxncincMXWuoo
IO O Q
IO O O
UA< A-
X cacq
WHQOOftIO WNWOn
OXOOOXO<AQcAO
CQMD < rH (MCA
QWUXQO
O H4 <QMH
O'fflOWXH
(M cm cm cm cm (A
a-a- a-a-a-
o o o o o o
05 0)
£ £
• H -H
CO *H
p
a
05
£
X P
X
o
£
£
0)
05
4 r“1
3
05
p p
P X
05 P
(0
O
P
05
* o Cm
O
£
(0
£
K 05 05
(0
O P
P
P O
P
•H
P £
0) P P
O P P
A-
05
£
£ 05
O P
P
X
•H O
P CC-H
o o
£
o
>> E
bOP
CO -H
>3
X £ T5
£
Cm
P P X
o co cd
p
o
cd 05 p
•H c
cd
SO £
P
p
p
05 P P
p p
p
p
3 ox
•H
P O
3
b CJ • 05
3 P
£
05 05 x
P O 03 P 0-
o cd
p
X
cd cd o
• O
Cm T 3
cd
£
P • P
P 05 P
05
P X P CO
O P O Eh
0) P x
A- 05
X o
CO X
•H
05
cd CO -H P 05 P
05 P P
p
OP U-H
cd O O CO >
bO o
p
O A-
o w
05
A-
X O A- O
05
10 -H P o
P £ cd
p
co Cd £
P p cd P
s*
p
bfl 05
bOr* E
>3p X>
co a- b£/csj bo
P
P
05 05 X £ Cm
•H P
3
P P P-H
cd P p cd
Cd CJ M
•H 05
o
o o
£ P
T3
O
p
X X -H 05 -H
0) O W
o
3 oj cd «m
X P cd o
x ido
X bO
• cd
• cd P «M Q5
X
• 05 «
x —
P CO
cd
o
bO* POP
bO x
O > X
O 05 X P
c X cd x cd
CO XP X Cm
•HEX
O
CO 05 03
O P
• cd
p
•H
>3 £ CO -H x CO
cd O Cm
O CJ o
P CJ X-H
X
CO X-H
05 CO
o
0) CO
P
05 V-, 05
P o
to 05 05 TJ
co
CO
Cd-H p 05
•H P p
o j* bi
X C -H
. 0)
P-H P
>3-*
£ -
P -H p
>3 0) SP £
05 X X £
05
cd
E £ • 3 XP
P 05
o
CO -H P P CO
CO > P
X P P
O
w
O £
£
£
£
>3 O P cd
P CQ
^ cd 03 • E
P co
s "s
P O 05 P cd
0) O 05
0) p cd «m cd «m 0)
05 -H
O X -H X
O «M
05 05 O 3 O
cd 05
X X t>0 co 3
>3 E bo P co o
-H X
•H >>
TD P,
O
•H X -H
O -H
E >3 £ X bO o P
co cd
P vS
05 >>
P X
£
viB
— £> 05
rH O £
cd -H Cm -H
E P O rH
•H *H
O (0 X X
05 O £ O
X X 05
P £
O 05
X
p
X o
O X
p p
05 cd
(0 P
0) CO
p
05
• x:
>jp
i P
o o
E P
05
P 05 P
>>£ O
£-h P
§ +*
a e
> *H
X o
05 X X
c E
05
O JC
t»D O
O X 05 S
-X O > i
P O
O P X *
£ - £ 05 r
£ 05 5
X O
•H'd -X
CO -H
05
P,Ow7>
P
P
9.
CO P
•H »
£
0) p
E X
0) X
X P X 0)
H >j P CO
o x cd co
X
5 s
was
X X > -X CQ
< C^-O
X X Q
S CQ W > m 5-H
DIOZX
x X 5-3 s <0
2 > O
*-i S H
3: CQ
WXXK
x a
x _
XCQ5-
03SXN
X X <Ob
o
o
o
Q O o
cc
Eh i-3 g 5-3 X W
XX * X H 3 M3 X 5-3 < W -
»A2<nQl>HU* XH5 x
> CQ 5-3
X ^ ^ *h *-HMM5HX>5-H
X2O2NgSXNft.M0/2;X>2O(n
o^s<x3So'-^oh)O h ^5-3SHSo.
LAO
V.. A- < g - 5-3 <
•0 5-3 os - 3 --o-
X<noOCMQSX>S<Ot-3
>
HHX>H^JEhH > X X H > 5M >
*“* “ ^''"~'2oqXoOXS>OXO
s < s
•O -M
<COS>
> Hi > X
O X o s
S o s X
g
>
X
o
o
5-3
o
n
w
w
Ml < O
-o - -
<-3- 5-3 <
> M > ►
O Q O ‘
s < s;
<
LAX
< 5 CA
•Q -
X X > < 5-3
o > X 5-H <
Q O s > 2
< s X s <
S X X
Q • O O
> < a cq
S >hm
0X2
X S O X
Q
>
P
X
E
•Q H X
X > o o
5-H c Ml 5H
> a q 2
S 5-3 < <
>j
£ P
5 cd cd
< rO
1, 05
P 05
) CO o
i cd cd
? x
cq - Eh -
X X b <
CM - O -
XO x
C/3 5H 5-H
D 2 X (SI X
X M O X O
vava < WMD W
WXNNWX
l§
CM W A- rH V
O CAA-X f
IS
Q I CM
l§
IX
IrA
:mcAfi3-
5 CM O X C
JHVOAO
5 CM (ACM A-
W CM A'-
Q O O
W < A-CAfA'X Q\0 X M'O A-CA QvQ X tl O NiAWLACM O ft! C
X Q NCM U AN W^O Nft, NO A*-O'O CACO vO O <A < O A-X C
CM M3
O
) LAX W < PI
1 X Q X O X
Page 40
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
279
SOME USEFUL SYSTEM ADDRESSES
ROUTINE DOBB’S VERSION ADDRESS
I.A. VERSION ADDRESS
PRTSTG
063C
0560
GETLIN
05D6
04FA
CRLF
OOOE
OOOE
ENDCHK
05A0
04C2
FNDLN
0614
0538
PARN
04FB
041A
AH0W
00A0
O0A0
TWO S-100 GRAPHICS PRODUCTS COMPARED
Dear Sir: Received: 78 May 12
Since I have benefited so frequently from the philosophy
of DDT s communications I wish to pass along an evaluation
which may help someone else decide between two expensive
graphics interfaces for the S-100 bus. The Super Dense Merlin
and the Matrox ALT-256**2 cost about the same but have
different features which may not be obvious until you have
gone to the expense of purchasing both. I already had an
established computer system and needed a graphics interface
as part of an economical prototype suited for self-instruction
by simulations of physiological systems.
Initially the Merlin was the only alternative so I invested in
the double board and a third tier to get 320 H by 200 V dot
resolution graphics plus ASCII characters. The factory-
assembled board was complete and met specifications but it
was very exasperating to implement in any of my collection
which includes two Altairs, a TDL ZPU, and a SOL. A major
source of difficulty was associated with its DMA on the S-100
bus, a familiar problem to many these days. A major part of
my memory investment was not compatible, the Z-80 was
usable, but not the 8080A when the DMA was enabled. In the
SOL (with no front switches) I could not disable the Merlin
DMA to even initialize the display parameters.
In the meantime the ALT-256**2 became available, and to
meet a pressing deadline I took a chance on a second invest¬
ment in it. This factory-assembled board had a solder bridge
which kept two of the port decoding bits high and made the
screen respond to addresses as commands (how did that pass
a “24-hour burn-in”?). Once this was found and removed it
has been sheer joy to apply the graphics. Within a day I made
up for several months of lost time.
The Merlin can be configured for keyboard and cassette
tapes, may have an on-board ROM monitor and editor; thu..
it can be a basic operating system. The Matrox, on the other
hand, displays dots on a screen, and nothing more. A compari¬
son of the features of each follows, viewed with a bias of my
particular needs.
The Merlin DMA slows down the CPU to 43% normal oper¬
ation speed as the video signal is being generated whereas the
Matrox does not. If there is any flicker in either one this is not
noticeable and not as important as the computation speed in a
simulation application. The user must supply 8K of memory
for the Super Dense graphics whereas the Matrox has 8K of
dynamic RAM included on board (a costly component).
On the Merlin, dot information is in successive 8-bit mem¬
ory locations, the addresses of which do not easily relate to
the X and Y coordinates on the CRT screen; but since the
Matrox has 256 x 256 dots the dot addresses correspond
nicely with the position on the screen. The CPU communicates
with Merlin by memory addresses (not moveable if the sup¬
plied monitor is used) whereas the Matrox uses 4 output ports
and 1 status input port. For the latter one output sets the X,
another sets the Y, and a third turns the dot off or on. A
fourth output clears the screen within microseconds whereas
the Merlin requires a software routine lasting seconds.
The Merlin has several display options including hardware
ASCII of 16 lines of 40 characters; three different densities of
graphics, and both mixed characters-graphics and splitscreen
displays of the two. The Matrox requires software generated
ASCII characters to be placed in memory, however this board
may be synchronized with an ASCII board to give mixed dis¬
plays. Also several graphics boards may be synchronized to
give multiple levels of intensity to each dot.
If you want to get an integrated operating system and
graphics package and expect no DMA problems, the Merlin is
worth your consideration. If you want to add graphics to an
existing system then the ALT-256**2 is apt to be more suit¬
able. With the growing interest in graphics capabilities, compe¬
tition is apt to produce packages at less cost than either of the
ones described here.
Yours Truly, 609 South Jordan
James E. Randall Bloomington, IN 47401
SELECTOR II REPORTING SYSTEM
News Release Received: 78 April 28
Selector II is a data entry and demand reporting system for
users of CP/M and Microsoft Extended Disk BASIC. It
provides timely information at the user’s fingertips, as well as
allowing on -line updating of data files.
Unique reports can be generated in minutes, with no pro¬
gramming experience required. The required information is
simply selected with any variety of conditions desired and in
the order wanted. Output can be used by programs, displayed
or printed as a titled, columnized report.
One-time license price of $225 includes 1-yr warranty.
Selector II is available on single-density 8” diskette complete
with user’s manual from Micro-Ap, 8939 San Ramon Road,
Dublin, CA 94566; (415) 828-6697.
QUAY 80 FI-S-100 DISK SYSTEM
News Release Received: 78 May 15
A floppy disk system for use in S-100 bus computers is a-
vailable from Quay Corp., P.O. Box 386, Freehold, NJ 07728.
The Quay 80 FI system, priced at $795. includes the Q/80
FDC-floppy disk controller board (capable of supporting up
to four disks), QDOS—disk based operating system, the
Q/FD1 125 KB 5%” band-driven disk drive with power regu¬
lator and interface cable, and the Q/80 FC—floppy disk cabi¬
net. Add-on drives (Q/FD1) are priced at $395. each. In addi¬
tion to the floppy disk support, the Q/FDC has available a
programmable 8-bit, TTL compatible, parallel I/O port capa¬
ble of supporting standard peripheral devices such as line
printers, tape punches, keyboards, etc. Product availability is
30-60 days ARO.
Number 26
280
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
A Z-80 Disassembler inTDL 8K BASIC
Dear Dr. Dobbs: Received: 78 April 20
In the March 1977 issue of DDJ you published an anony¬
mous listing for an 8080 disassembler. For any student of
BASIC this was a beautiful bit of work. I can’t hope to come
close to the original in compactness of code work but anyhow
have tried to build on it as best as possible. Enclosed is the
Z-80 version, written in TDL’s 8K BASIC and generating
TDL’s mnemonics.
The line numbers are fairly well preserved from the original
version but all of the comments have been omitted for
memory compactness. You shouldn’t have much trouble figur¬
ing out what was done from the original listing. Some changes
were made for my own convenience. First, it was necessary to
use “escape” characters to control the screen clearing, etc. on
my relatively smart terminal. Second, the listing is controlled
by a start and end address which are specified after the “>”
sign. Third, the listing is continuous and I have eliminated the
“J” routine. Fourth, the screen clearing activity is made to
progress during the time that the files are being loaded. This
goes with the smart terminal. Finally, the machine codes are
printed along with the mnemonics. I still like to see the
machine code since I grew up that way.
In the spirit of the original version, please omit my name
and address from this article.
This is an example of how the disassembler works. It is
disassembling a portion of the BASIC (TDL 8K) on which it
is running, of course.
Note the limitation on memory address, so the BASIC
had to be moved to a lower address for the disassembly.
40 DIM B(b)
50 GOSUB 9O40-.HEM BASED ON BOBO DISASS.— DDJ MAH 1977
102 PRINT ES$;CH$;ES$;CS$:GOSUB 9030
110 PRINT " Z-B0 DISASSEMBLER".'PRINT
160 PF=TRU£
210 PRINT
215 GOSUB 220:GOSUB 5600
216 IF C*=" " OR C$="Z" OR C$="-" THEN GOTO 430
217 GOTO 210
220 GOSUB 5600
250 IF C$>="0" AND C$<="7" GOTO 300
260 IF PH THEN GOSUB 6200:GOTO 220
300 T=C-ASC("0"):N=1
310 GOSUB 5600
320 IF C$>="0" AND C*<="9" THEN D=C-ASC("0"):G0T0 400
330 IF C$>="A" AND C$<="F" THEN D=10+C-ASC("A") :GOTO 400
340 IF C=127 THEN PRINT CR$;ES$;EL$;:G0T0 210
350 IF PH THEN GOSUB 6200
360 GOTO 310
400 T=D+16*T:N=N+1
420 IF N<4 GOTO 310
425 RETURN
430 PC=T
440 IF PC<=32765 GOTO 450
445 GOSUB 530:GOTO 210
450 GOSUB 220:GOSUB 5600
452 IF C$=CR$ GOTO 455
454 GOTO 450
455 PE=T
456 IF PE<=32765 GOTO 900
530 PRINT "ADDRESS TOO HIGH":RETURN
900 PRINT CR$
1000 REM “MAIN LOOP**
1002 Nb=0
1010 X=PC:GOSUB 5450
1020 PRINT ”: ";:PRINT TAB(15);
1030 GOSUB 5000:OP=X
1040 GOSUB 2060
1045 PRINT TA6(33);
1046 FOR 1=1 TO NB:X=B(I):PRINT SPC(1);:G0SUB 5100:NEXT
1047 PRINT
1050 IF PC<PE GOTO 1000
1060 END
2000 L=INT(0P/B1T(6)):M=INT(0P/BIT(3)) AND 7:K=0P AND 7:RETURN
2060 GOSUB 2000:ON L GOTO 3010,3210,3510
2120 ON X GOTO 2210,2410,2510,2610,2610,2710,2810
2132 IF M=1 THEN S$="EXAF"
2133 IF M=0 THEN S$="N0P"
2134 IF M=1 OR M=0 GOTO 5700
2136 S$=JR$(M):G0SUB 6000
2136 GOSUB 5000:GOSUB 7000:GOSUB 5450:RETURN
2210 K=M/BIT(1)
2220 IF OP AND BITC3) GOTO 2310
2240 S$="LXI ":GOSUB 6000
2250 S$=RP$(K):GOSUB 6000
2260 S*=" , ":GOSUB 6000
2270 GOSUB 5400:RETURN
2310 S$="DAD ":GOSUB 6000
2320 S$=RP$(K):G0T0 6000
2410 S$=02$(M):GOSUB 6000
2420 IF M<4 THEN RETURN
2440 GOSUB 6100:G0SUB 5400:RETURN
2450 GOSUB 5400:RETURN
2500 REM
2510 K=INT(M/BIT(1))
2520 M=M AND BIT(O)
2530 IF M=0 THEN S$="INX "
2540 IF M=1 THEN S*="DCX "
2550 GOSUB 6000
2560 S$=RP$(K):G0T0 6000
2610 IF K=4 THEN S»="INR "
2620 IF K=5 THEN S$="DCR "
2630 GOSUB 6000
2640 S*=REG$(M):GOTO 6000
2710 S$="MVI ":GOSUB 6000
2720 S$=REG$(M):GOSUB 6000
2730 S*=»,":G0SUB 6000
2740 GOSUB 5200:RETURN
2810 S$=07$(M) -.GOTO 6000
3010 IF M=6 AND K=6 GOTO 3160
3020 S$="M0V ":GOSUB 6000
3030 S$=REG$(M):GOSUB 6000
3040 S$="Z ":GOSUB 6000
3050 S*=REG$(K):GOTO 6000
3160 S»="HLT":G0T0 6000
3210 S$=AI$(M):GOSUB 6000
3220 GOSUB 6100:GOTO 3050:RETURN
3510 ON K GOTO 3570,3610,3805,3630,4005,4120,4210
3530 S$="R":GOSUB 6000
3540 S$=CC$(M):G0T0 6000
3570 S$=C1$(M):GOTO 6000
3610 S$="J":GOTO 3650
3630 S$="C"
3650 GOSUB 6000
3660 S$=CC$(M):GOSUB 6000
3680 GOSUB 6100
3690 GOSUB 5400
3695 JF=TRUE:RETURN
3805 IF M=1 GOTO 7200
3810 S$=C3$(M):GOSUB 6000
3820 IF M=0 GOTO 3850
3630 IF M=2 OR M=3 GOTO 3900
3840 RETURN
3850 GOSUB 6100:GOSUB 5400:JF=TRUE:RETURN
3900 GOSUB 6100:GOSUB 5200:RETURN
4005 IF M=5 GOTO 7400
4006 IF M=3 THEN I$="X"
4007 IF M=7 THEN I$="X"
4008 IF M=3 OR M=7 GOTO 7700
4010 S$=C5$(M):GOSUB 6000
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
281
1(020 IF MOI ThEN RETURN
401(0 GOSUB 6100:GOSUB 5400:JF=TRUE:RETURN
4120 S$=C6$(M):GOSUB bOOO
4130 S$=" ":GOSUB 6000
4140 GOSUB 5200:RETURN
4210 S$="RST ":GOSUB bOOO
4220 X=8*M:GOSUB 5100
4230 JF=TRUE:RETURN
5000 X=PEEK(PC):PC=PC+1:NB=NB+1:B(NB)=X:RETURN
5100 PRINT HEX$(1NT(X/16));HEX$(X AND 15);:RETURN
5200 GOSUB 5000:GOSUB 5100:RETURN
5300 REM
5330 GOSUB 5000:XL=X
5340 GOSUB 5000:XH=X
5350 X=XL»256»XH:RETURN
5400 GOSUB 5300:GOSUB 5450:RETURN
5450 T=X:X=INT(T/256):GOSUB 5100
5470 X=T-256*X:GOSUB 5100
5480 X=T:RETURN
5500 WAIT TS,KB:C=INP(TD) AND 127
5525 IF 0=97 AND C<=122 THEN C=C-32
5530 C$=CHR$(C):RETURN
5600 GOSUB 5500
5640 PR=C>=32 AND C<=126
5650 IF PR THEN PRINT C$;: RETURN
5700 GOTO 6000
6000 IF PF THEN PRINT S$;" :RETURN
6100 IF PF THEN PRINT " :RETURN
6200 PRINT BS$;ES$;EL$:RETURN
7000 IF X<=127 GOTO 7040
7030 X=X-256
7040 X=PC+X:RETURN
7200 GOSUB 5000:OP=X
7212 L=INT(0P/BIT(6))
7214 M=INT(OP/BITC3)) AND 7
7216 K=OP AND 7
7220 IF L=0 GOTO 7280
7230 S$=CB$(L):GOSUB 6000
7240 S$=CHR$(48+M):GOSUB 6000:S$=",":GOSUB 6000
7260 S$=RSG$(K):GOTO 6000
7280 S$=RT$(M):GOSUB 6000
7300 S$=REG$(K):GOTO 6000
7400 GOSUB 5000:OP=X
7410 L=INT(OP/BIT(6)):M=INT(OP/BIT(3)) AND 7:K=0P AND 7
7430 ON L GOTO 7450,7690,7440
7440 S$="- GOSUB 6000:RETURN
7450 ONK GOTO 7480,7500,7550,7600,7620,7650,7680
7460 S$="INP":GOSUB 6000
7470 S$=REF$(M):GOTO 6000
7480 S$="OUTP":GOSUB 6000
7490 S*=REG$(M):GOTO 6000
7500 K=INT(M/BIT( 1)) :M=M AND BIT(O)
7520 IF M= 1 THEN S$="DADC"
7530 IF M=0 THEN S$="DSBC"
7535 GOSUB 6000
7540 S$=RP$(K):GOTO 6000
7550 K=INT(M/BIT(1)):M=M AND BIT(O)
7560 IF M=0 THEN S$=''S"
7570 IF M=1 THEN S*="L"
7575 GOSUB 6000
7580 IF K<>2 GOTO 7590 ELSE S$="-?-"
7585 GOTO 6000
7590 S$=RF$(K):GOSUB 6000
7592 GOSUB 5300:G0SUB 5450:RETURN
7600 IF M=0 GOTO 7610
7602 S$="—":GOTO 6000
7610 S*="NEG":GOTO 6000
7620 IF M<=1 GOTO 7630
7622 GOTO 7602
7630 IF M=1 THEN S*="RETI"
7632 IF M=0 THEN S$="RETN"
7640 GOTO .6000
7650 IF M=1 OR M>3 THEN S$="-t-"
7660 IF M=0 THEN S$="IM0"
7662 IF M=2 THEN S$="IM1"
7664 IF M=3 THEN S$= n IM2 M
7670 GOTO 6000
7680 S$=ED$(M):GOTO 6000
7690 S$=CP$(K):GOSUB 6000
7695 S$=CP$(M):GOTO 6000
7700 GOSUB 5000:OP=X
7705 IF 0P=203 GOTO 7820
7710 L=INT(0P/BIT(6)):M=INT(OP/bIT(3)) AND 7
7712 K=OP AND 7
7714 ON L GOTO 7770,7790,7799
7720 ON K GOTO 7724,7736,7740,7750,7750,7760
7722 S$="==":GOTO 6000
7724 IF M=4 GOTO 7731
7725 K=1NT(M/BIT(1)):M=M AND BIT(O)
7726 S$="DAD":GOSUB 6000:S$=1$:G0SUB 6000
7727 IF K=2 GOTO 7730
7728 S$=RP$(K):GOTO 6000
7730 S$=I$:GOTO 6000
7731 S$="LXI":GOSUB 6000:S$=I$:GOSUB 6000
7732 S$=",":GOSUB 6000:GOSUB 5330:GOSUB 5450:RETURN
7736 IF M=4 GOTO 7739
7737 S$="LI":GOSUB 6000:S$=I*:G0SUB 6000
7738 S$="D":GOSUB 6000:G0SUB 5330:GOSUB 5450:RETURN
7739 S$="SI":GOSUB 6000:S$=I$:GOSUB 6O0O:GOTO 7738
7740 IF M=4 THEN S$="INX"
7742 IF M=5 THEN S$=“DCX"
7744 GOSUB 6000 :S$=I$: GOTO 6000
7750 IF K=4 THEN S$="INR"
7752 IF K=5 THEN S$="DCR”:GOSUB 7754:RETURN
7754 GOSUB 6000:GOSUB 5000:GOSUB 5100
7755 S$=»l":GOSUB 6000:S*=1$:GOSUB 6000
7756 S$=")":GOTO 6000
7760 IF M<>6 GOTO 7722
7762 S$="MVI":GOSUB 7754:S$=" ":GOSUB 6000:G0SUB 5200:RETURN
7770 S$="MOV"
7772 IF K=b GOTO 7780
7774 GOSUB 7754:S$=",":GOSUB 6000
7776 S$=REG$(K):GOTO 6000
7780 GOSUB 6000:S$=REG»(M):GOSUB 6000:S*="Z"
7782 GOSUB 7754:RETURN
7790 IF K<>6 GOTO 7794
7792 S$=AI$(M):GOSUB 7754:RETURN
7794 S$="~":GOTO 6000
7799 IF M<>4 GOTO 7810
7800 ON K GOTO 7804,7802,7805,7802,7808,7802,7802
7802 S$="—":GOTO 6000
7804 S$="POP":GOTO 7809
7805 S$="XTI":GOTO 7809
7806 S$="SPI":GOTO 7809
7808 S$="PUSH"
7809 GOSUB 6000:S$=I$:G0T0 6000
7810 IF M<>5 GOTO 7814:IF KOI GOTO 7802
7812 S$=”PC1":GOTO 7809
7814 IF M=7 AND K=1 GOTO 7806
7820 GOSUB 5000:D=X:GOSUB 5000:OP=X
7822 GOSUB 2000
7826 IF L>0 GOTO 7840 ,
7830 IF K<> 6 GOTO 7B02
7832 S$=RT$(M):GOSUB 6000
7834 X=D:GOSUB 5100:S$="(":GOSUB 6000
7836 S$=I$:GOSUB 6000:S$=")":GOT0 6000
7840 S$=CB$(L):GOSUB 6000
7842 S$=CHR$(48+M):GOSUB 6000
7844 S$=",»:GOSUB 6OO0:GOTO 7834
9030 DIM HEX»(15)
9040 FOR 1=0 TO 15:READ HEX$(I):NEXT
9050 DATA "0", , 1","2",*3","4","5","6" ,"7" ."8","9".A,B,C,D,£,F
9080 DIM BIT(7)
9090 FOR 1=0 TO 7:READ BIT(I):NEXT
9100 DATA 1,2,4,8,16,32,64,128
9130 DIM REG$(7)
9140 FOR 1=0 TO 7:READ REG$(I):NEXT
9150 DATA B,C,D,E,H,L,M,A
9180 DIM RP$(3)
9190 FOR 1=0 TO 3:READ RPt(I):NEXT
9200 DATA B,D,H,SP
9203 DIM RF$(3)
9204 FOR 1=0 TO 3:READ RF$(I):NEXT
9205 DATA BCD,DED,HLD,SPD
9230 DIM AI$(7)
9240 FOR 1=0 TO 7:READ AI$(I):NEXT
9250 DATA ADD,ADC,SUB,SBB,ANA,XRA,ORA,CMP
9280 DIM C6$(7)
9290 FOR 1=0 TO 7:READ C6$(I):NEXT
9300 DATA ADI,ACI,SU1,SBI,ANI,XRI,0RI,CP1
9312 DIM JR$(7)
9314 FOR 1=2 TO 7:READ JR$(1):NEXT
9316 DATA DJNZ,JMPR,JRNZ,JRZ,JRNC,JRC
9330 DIM CC$(7)
9340 FOR 1=0 TO 7:READ CC$(I):NEXT
9350 DATA NZ,Z,NC,C,PO,PE,P,M
9390 DIM C1»(7)
9400 FOR 1=0 TO 7:READ C1$(I):NEXT
9410 DATA POP B,RET,POP D.EXX.POP H,PCHL,POP PSW.SPHL
9440 DIM C3$(7)
Number 26
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
9*150 FOH 1=0 TO 7:READ C3*(l): NEXT
9460 DATA JMP,- -,0UT,1N,XTHL,XCHG,D1,E1
9490 DIM C5$(7)
9500 FOR 1=0 TO 7:READ C5$(I):NEXT
9510 DATA PUSH B,CALL,PUSH D,- -.PUSH H,- -.PUSH PSR,- -
9540 DIM 071(7)
9550 FOR 1=0 TO 7:READ 07*(1):NEXT
9560 DATA RLC,RRC,RAL,RAR,DAA,CMA,STC,CMC
9590 DIM 02$(7)
9600 FOR 1=0 TO 7:READ 02$(1):NEXT
9610 DATA STAX B.LDAX B.STAX D.LDAX D,SHLD,LHLD,STA,LDA
9625 DIM OBJ(3)
9630 FOR 1=1 TO 3*READ CB*(I):NEXT
9640 DATA BIT,RES,SET
9655 DIM HT$(7)
9660 FOR 1=0 TO 7:READ RT$(1):NEXT
9670 DATA HLCR, RRCR, RALR, RARR, SLAR, SRAR, —, SRLR
9680 DIM ED*(7)
9690 FOR 1=0 TO 7iREAD ED$(1):NEXT
9695 DATA STAI.STAR,LDA1 ,LDAR,RRD,RLD, —,—
9700 DIM CP$(7)
9702 FOR 1=0 TO 7:READ CP$(I):NEXT
9704 DATA LD,CP,1N ,OUT , I ,D, 1H ,DR
9620 TRUE=-1:FALSE=0:RETURN
9840 TS=2:TD=3:Kb=2:SB=2
9660 BS=6:BS$=CHR$(BS)
9670 CS=74:CS$=CHR$(CS)
9880 EL=75:EL*=CHR$(EL)
9890 CR=13:CR$=CHR$(CR)
9895 ES$=CHH*(27)
9697 CH$=CHR$(72):RETURN
READY>
RUN
HJ
Z-80 DISASSEMBLER
>3000 30IF
3000:
XTHL
E3
3001:
POP b
Cl
3002:
XCHG
EB
3003:
XTHL
E3
3004:
INX B
03
3005:
LD DR
ED
B8
3007:
INX H
23
3006:
INX D
13
3009:
MOV B , D
42
300A:
MOV C , E
4B
300B:
POP D
D1
300C:
RET
C9
300D:
PUSH H
E5
300E:
LHLD 01B6
2A
B6
01
3011:
MV I B , 00
06
00
3013:
DAD B
09
3014:
DAD B
09
3015:
CALL B11A
CD
1A
B1
301b:
POP H
El
3019:
RET
C9
301A:
PUSH D
D5
301B:
XCHG
EB
301C:
LXI H , FFD8
21
Db
FF
READY>
COMPUTER NETWORK POLL
DDJ: Received: 78 April 28
I read your letter by Jef Raskin, in Volume 2, Issue 10,
about the D.C. Hayes modem board.
Randy Suess and I now have one on-line 24 hours a day in
a computerlized call-in bulletin board system. We are quite
pleased with it, and wanted to pass on our experiences, and
also invite your readers to try it first hand. But first, some
background on the system.
On January 16, 1978, I thought up the idea of a hobby
computer-based bulletin board system, as a source of material
for our club newsletter. I talked over the idea with Randy
Suess, and we decided to go ahead and do it. I would do the
software, and he would do the hardware.
We based it on a 24K 8080 system, using the Tarbell disk
controller, and an Innovex floppy drive. The D.C. Hayes
board, going thru a DAA, provided the phone link.
Within 30 days, we had the system designed, built,
programmed, and tested. Shows what can be done if you
really put your mind to it.
It has undergone very minor changes since going on the air
in mid-February. A few resistor values were changed on the
DC Hayes board, and a higher precision op amp was substitut¬
ed, all based on work by Randy, and suggestions by Dennis
Hayes.
We are now quite happy with the system. It is regularly
called from California, Georgia, Ohio, as well as lots of local
calls. It performs well with the possible exception of having
trouble when the modem being used does not put out a strong
signal. Very few people have had trouble receiving the signal
we send out.
We are currently using a revision 3 modem board, and
expect to be trying out a revision 4 board shortly (should be
in place by the time this letter is printed).
We invite your readers to give it a try. We will take an
informal poll of success or lack of it, and will report back to
you.
Here is how to access the system: Any ASCII terminal, 110
or 300 baud, should work. There is no “protocol” associated
with the system. It uses 2 stop bits at 110 baud, 1 at 300. It
echoes everything typed, character by character, but this may
be changed after signing on. For the time being, no password
is required to access the system. We encourage its use, but may
have to go to a password system if it gets abused.
Dial the system (312) 528-7141, and when you hear the
answer modem tone, connect your modem. Then press return
several times until the system responds. (C/R is used as the
speed determining character). You will be prompted from then
on.
NOTE: People who are successful will of course be known
to us, but people who are unsuccessful won’t. That’s not right,
as it gives a falsely biased view of the system’s success. I there¬
fore ask people who are unsuccessful in communicating to call
me, Ward, at (312) 849-6279. I have a recorder on the phone
in case I am not home. I would appreciate the callers having
the following information ready to give in case the recorder
answers the phone: Where they tried calling the system from;
What type of modem was being used; What type of terminal;
What speed; Any comments they think might help. I don’t
have the budget to return all the calls, but will try to handle
those of interest and particularly those who might have useful
suggestions.
Both Dennis Hayes and Dave Caulkins (PCNET) have
received copies of the software, as they are very serious about
setting up their own systems. We encourage other clubs to set
up similar systems. The software is copyrighted, but something
should be able to be worked out. The copyright is just to
maintain control, not to limit its non-commercial use. A more
detailed article on the system will be coming out in a Fall
BYTE.
Happy Computing, 688 E. 154th St.
Ward Christensen Dolton, IL 60419
Page 44
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
283
MORE DOPE ON NIBL
’NUFF SAID
Dear Dr. Dobb: Received: 78 April 3
Mike Fern’s “nips at NIBL” inDD/No. 22 contained sever¬
al errors which deserve correction. The mysterious “JS”
instruction he refers to is a pseudo-instruction recognized by
the SC/MP cross assembler, and is documented in the SC/MP
Assembly Language Programming Manual, publication number
420009C, January 1977. The JS instruction generates a
sequence of five instructions occupying seven bytes of code.
The actual sequence generated is: LDI, XPAH, LDI, XPAL,
XPPC; the effect is to perform a long jump or subroutine call.
In the NIBL source file, the assembler was directed (at line 2)
to list no more than the first 2 bytes produced by any direc¬
tive capable of generating more than 2 bytes of code, such as
the JS instruction or ASCII directive. Thus, there are exactly
five missing bytes of code in the listing at each occurrence of
a JS, not 4 or -1 (!) as Mr. Fern claims. I suspect his hexadec¬
imal arithmetic was a little rusty when he make those calcula¬
tions.
By the way, SC/MP users will be pleased to note that the
missing code appears in the load module produced by the
assembler, and that the version of NIBL published in
Dr. Dobb’s actually runs, bugs and all.
The bug in NIBL (actually a design error) regarding the
definitions of “true” and “false” has already been beaten
pretty well into the ground by Jef Raskin. There are two
possible fixes for the problem:
1. Change the definition of “true” in logical expressions to
-1, rather than 1.
2. Change the code for the IF and UNTIL statements so
that only the least significant bit of the logical expres¬
sion is checked for 0 (false) or 1 (true).
At the time Jef reported the bug to me, NIBL had already
been released and was being made into PROMs in great quanti¬
ties for shipment (another way of saying the program was cast
in concrete). If you don’t like the way NIBL works, don’t
panic—change the rotten interpreter. I would implement
fix #2 above by changing the OR instructions at addresses
5DB and 932 to ANI 1 (referring to the listing in Dr. Dobb’s
—the released version of NIBL will have slightly different
addresses).
NIBL was not designed to sway followers of any particular
Comp. Sci. guru (such as Dijkstra) away from their discipline
of programming. It was built as a tool for helping a few hard¬
ware engineers debug their applications involving SC/MP, not
as a language for writing business software or compilers.
Admittedly, it is an atrocious language by most standards, but
I would prefer that people compare it with languages in its
class, namely the various dialects of Tiny BASIC. In all
modesty, NIBL doesn’t seem too bad by these lowered stan¬
dards, aside from the fact that the interpreter is twice as large
and 50 times as slow as Lichen Wang’s excellent TB implemen¬
tation (a result of having to use a hopelessly weak, slow
processor).
I can’t seem to find two people who will agree on some of
the non-standard features in NIBL. Raskin hates the
notation for memory access, while Albrecht likes it; yet Raskin
likes the DO/UNTIL structure and Albrecht condemns it as
completely contrary to the spirit of BASIC. Personally, I find
most dialects of BASIC (including NIBL) to be distasteful for
writing large programs (i.e., programs longer than 10 lines).
NIBL should have remained in-house at National, but the
marketing people (to whom all us peon programmers are slaves,
more or less) saw it as a good gimmick to promote sales of
SC/MP chips. Thus, I was pressured to publish both the listing
and a quickie write-up full of errors before NIBL was really
To All Multi-Micro Media Customers: Received: 78 May 15
Thank you for your order. It is most appreciated.
The purpose of this letter is two-fold: to acknowledge your
order and to explain when, if ever, you can expect to receive
it.
At present we have not received sufficient orders for some
of the products to make it economically feasible to produce
them at this time. The schedule below is our best guess as to
when the order level will warrant producing the most minimal
quantities for shipping.
PRODUCT
FORECAST
PROBABLE SHIPPING DATE
H8-BG1
Unclassifiable
Unknown
H8-BG2
Unclassifiable
Unknown
H8-MG1
Unclassifiable
Unknown
H8-MG2
Unclassifiable
Unknown
H8-MG3
Unclassifiable
Unknown
H8-MG4
Poor
July 1
H8-CODE
Unclassifiable
Unknown
H8-KING
Unclassifiable
Unknown
H8-DISM
Good
June 15
H8-EDUC
Good
June 1
R8-BG1
Excellent
May 1
R8-BG2
Very Good
May 15
As of May 1, 1978, we intend to re-evaluate the status of
ALL orders for ALL products. At that time, any product
whose forecast is still “Unclassifiable” will be cancelled and
the orders for that product will be returned.
In the meantime, anyone who wishes to cancel an order is
invited to to so. We will return your original order document
and if payment was rendered by check, we will return your
check. In the case of money orders made payable to Multi-
Micro Media Corp., we will write a refund check for the same
amount back to you.
Unless advised to the contrary, products will be shipped
when produced and for credit card customers, you will be
billed one at a time. In the case of orders for a combination of
produced as well as cancelled products paid by check or
money order, an appropriate refund will accompany the first
product shipped.
Again, thank you for your order. We, like you, hope that
interest will increase in our product line to make it possible to
bring to you what we feel are good products. Your patience
during this trial-time is appreciated very much.
Sincerely,
MULTI-MICRO MEDIA CORPORATION
Operations Department P.O. Box 1025
(303)425-5221 Arvada,CO 80001
ready to be loosed upon the world. Judging by the generally
unfavorable reaction from readers of DDJ this seems to have
been a mistake.
Sincerely,
Mark Alexander 149 Jackson Ave. #200
Redwood City, CA 94061
Number 26
284
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
SAM76 Language Update
H The current position with respect to
I Source Code 11 availability of the source code is very
I I Availability j| staple: It is available la machine
IJ_LI readable form under the following
conditions:
1. - A relatively complex test must be passed with flying
honors to demonstrate the requestor's understanding of both
the language philosophy and pragmatics; one of the ten test
problems might be:
"Write a procedure named "FETCH" that precisely and
completely mimics the "FT" function".
2. - The requestor mu6t demonstrate shill and knowledge with
respect to assembly language programming as it relates to
the version of the source code desired; If the source code
Is desired as a model for Implementation In a new machine
then skill in the target machine must be demonstrated - team
work Is encouraged In this Instance.
Active and neutral execution of the "*I"
function reTeals the creation date and
version number respectively; versions
<0022” with a date equal to or greater
than 14CC have been modified as required
to permit portability of the actual work space. The creation
date code may be decoded using the following procedure:
< date*
,3i mr
Note that scripts output with the "OT" output text function,
are not in question and that the new version Is only
required If the user desires to move his work space to
machines where that space does not start at *h4 00.
fed, 1, fe u, fed, fe@n //, feu, 31, fe 1, fed, few n /,
i version |
I <0022* |
IJ_L
This function was added to delineate the
limits of the user work space; It may be
used at any time, but generally prior to
executing the "EX" exit function; formal
definition follows:
iI New function j j
11 "IQS" 11
IJ_LI
272 |xqs,s0|
X Query Save
3. - The requestor must be prepared to agree to contribute
free time towards the advancement of the language; this can
be In a number of ways Including Improving the efficiency of
existing source code, publishing algorithms and examples,
giving talks to school and other educational groups &c.
4. - The requestor must agree to make available for
publication at no charge any programs written either for
other machines, or as additions to the source version
requested. This does not, however, include any application
programs, normally referred to as scripts or procedures
written in the SAM76 language Itself.
The foregoing requirements are an attempt at preserving the
current Integrity and portability of the language until
enough Implementations have been made that a "DE FACTO"
standard Is established; the benefits to users of such a
position should be obvious.
The value of this function are two numbers, each preceded by
the string "s0" representing in the normal number base of
the machine the starting and ending adresses of the user
work space that should be saved.
Normally the "cws" change work space function would be first
executed to reduce the work space to a minimum size, then
the "xqs* function executed to ascertain the limits of the
required save, prior to doing an "exit".
Version <0022* 14CC corrects the non
functioning of the "XI" experimental
Input in the 8060 versions of the SAM76
language processor. The following shows
the changes that can be made In early
versions to correct this problem:
j failure of i
I "XI"
I in 8080 code |
J_L
Early version coding:
Corrected coding:
XI: MVI
A.KINP
XI:
MV I
A.KINP
Through an oversight all of the 1^3 calls
IT Tl
STA
CHA1
STA
CHA1
were not made through the vector table
II 1^) Vector j |
MV I
A.KRET
CALL
MSXX
created at “h400 In early versions of
the
11 Patch 11
STA
CHA142
MOV
L,A
object code distributed at San Jose;
this
II II
CALL
MSXX
MV I
H.KRET
anomaly was brought to our attention
the
STA
CHA1+1
SHED
CHA1+1
second day of the WEST COAST FAIRE,
and
the changes listed
CALL
CHA1
CALL
CHA1
below will correct the problem for users
with other than
JMP
MSXRB
MOV
C,A
“ZAPPLE" monitors:
JMP
MSXRB
Version location from
to
NOP
Z80 80C6 & 8116 CD 15 F0
CD
21 04
CHAl: 04DE
| KRET =
C9
1
KINP =
811F & 81CD CD 18 F0
CD
24 04
XI, MSXX, and
MSXRB locations
may vary
between
versions
8080 80E7 & 813B CD 15 F0
CD
21 04
8144 & 81F7 CD 18 F0 CD 24 04
"Tl The normal location for the Interpreter
I| Location of I j object code was assembled to start at
11 object code 11 ~h8000; this was a compromise selection
1 1 _ 1 1 due to the desire to have all of the user
work space In one continuous area
starting at 0 for the Z80, and ~h400 for the 8080; the idea
was to permit saving the user work space as an executable
load nodule that would be portable from machine to machine,
regardless of the location of the object code Itself (be it
below or above *h8000).
Since then it has become painfully obvious that such hope
could not be realized with regard to the POLYMORPHIC and
HEATHKIT systems; consequently changes have been made In the
object code to normalize certain pointers at the time the
"EX" Exit function Is executed, and restores these same
pointers as appropriate to the machine in which the smfed
user work space might be reloaded.
i r
ii
"CFC"
Tl
II
11 superfluous 11
II
11 -
argument
II
II
It was pointed out that the "cfc" change
fill character funtlon did not function
as defined - requiring an extra argument;
this may be readily corrected by
replacing with NOP the call to the
subroutine that moves the argument
pointer In the expression being evaluated:
CFC:
MV I
A.NULCT-TIR
; 3E IE
CALL
STORNO
IJSAS
; replace In
z80 with one NOP, 8080 3 NOPs
DCX
H
CALL
HSR9
MOV
M,A
IJRQ
Z80
version IJSAS
Is an RST2, In the 8080 version
In the
IJSAS Is assembled as a CALL to MSAS; the locations of CFC,
STORNO, MSAS, and MSR9 may vary between versions.
Page 46
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 26
285
SAM76 language afficlonadoes night like II II
to receive advance copies of material 11 <PREPR1HTS> j1
scheduled for publication. At this time |J_LI
it is suggested that those people wishing
to receive preprints may send to SAM76 a self addressed
envelope containing one dollar; this dollar will be replaced
with preprints as available and the envelope mailed - then
to continue if so desired %PREPRI!frs/.
An object code version tailored to the POLYMORPHIC should be
available by the tine this is published. The price is $6.00
postpaid for this as well as for version «0022». The 190
page textbook is priced at $12, and a system loader
information booklet is $2; all of these are postpaid.
Specify loose-leaf or bound preference for the text book.
SAM76 Inc., Box 257, R.R.l, Pennington, N.J., 08534
THIS IS SIRIUS
News Release Received: 78 April 13
Sirius II comes complete, using a unique combination of
two micro processors, the Mostek Z80 (for main computa¬
tions), and a Fairchild 3870, that handles all keyboard and TV
interface overhead. Also included are 32,768 characters of
read/write memory, RS-232 interface for I/O, 8,192 charac¬
ter PROM board with 1,000 character monitor supplied, mini¬
floppy disc drive, a 64 key keyboard with alpha/numeric and
graphic capabilities, and TV interface. Other features included
are a full disc operating basic interpreter, monitor and soft¬
ware programs (ranging from home management, personal
finance, educational learning programs, process control, to
games and more games). The Sirius II is also capable of run¬
ning the full complement of business software that its big
brother (Sirius IV) runs.
Presently available hardware includes additional RS-232
I/O, additional parallel I/O, add-on 16,384 BYTE RAM cards,
A/D-D/A converters, and additional mini-floppy disc drives.
The Sirius II is manufactured by Digital Sport Systems,
and has a suggested retail price of $1,850. Contact Digital
Sport Systems, 7th and Elm Streets, West Liberty, Iowa
52776;(319) 627-4211.
A BELL FOR YOUR SWTPC TERMINAL
Dear Sir: Received: 78 Feb 5
Enclosed is a circuit for adding a “bell” function to a
SWTPC CT-1024 terminal. The circuit consists_ of a 556 (dual
555) timer IC, four resistors, five capacitors, and a speaker. I
built the entire circuit on the 14-pin Wire-wrap socket that
the 556 is plugged into. The bell is triggered from an unused
output pin of the 7445 decoder on the computer controlled
cursor board in the CT-1024.
The left portion of the circuit is a one -shot with a duration
of about Vi second. The right portion is an astable oscillator
with a frequency of about lKhz. The output of the one-shot
is connected to the reset of the astable. When the one-shot is
triggered by a low-going pulse from the 7445 decoder on the
cursor board, its output goes high for Vi second. This high
pulse allows the astable to oscillate at lKhz for Vi second. The
IK resistor at the trigger for the one-shot is required to pull-
up the output of the open-collector 7445. The astable is
coupled to the speaker through a 10 mfd. capacitor. The
circuit I built plugs in “piggy-back” onto another 14-pin
IC (with Vcc= 14, Gnd=7). The cost is less than $4.00.
Sincerely,
Stuart Brown 12814 Taber St.
Ft. Wayne, IN 46803
TIME-SHARE FOR NORTH STAR
News Release Received: 78 April 6
A Time-Share Disk BASIC System is now available for
users of the North Star Floppy Disk System. Designed to oper¬
ate with either 8080 or Z-80 processors, NORTHSHARE tm
provides up to four independent users with selectable memory
partitions and buffered terminal outputs.
Minimum memory requirements for operation are 24K
bytes. There are no special hardware requirements outside of
additional terminals and I/O ports to support the multiple
users.
System includes one Diskette and Release 3 North Star
Basic and DOS with NORTHSHARE tm Supervisor and Docu¬
mentation Package. Price is $48. Byte Shop of Westminster,
14300 Beach Blvd., Westminster, CA 92683; (714) 894-9131.
Number 26
286
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 47
Dr. Dobbs JouRNALof
COMPUTER
(Calisthenics f) Orthodontia
Running Light Without Overbyte
Number 27 _ August 1978 _ Volume 3, Issue 7
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
SOFTWARE
A Compact 8080 Disassembler & Dumper Richard Greenlaw 4
How it works and how to use it
A IK Utilities Package for the Z-80 Les Hancock 22
A companion to the IK Debugger published by Dr. Dobb’s
A Shorter Printer Driver for PolyMorphic’s BASIC Richard B. Emerson 27
With an explanation of circular buffers
Fast Cassette Interface for the 6502 Carl Moser 31
A BASIC Renumbering Program John B. Trenholme 34
Adaptable to various versions of BASIC
Custom File Routines for ALS-8 Larry A. Marek 42
Common PILOT: Progress Report Larry Kheriaty and George Gerhold 46
HARDWARE
The Intel 8086 Mike Gabrielson
A look at Intel’s new 16-bit microprocessor
19
Unix
Dialogue
Continues
Dear Dr. Dobb’s: Received: 78 June 28
This is a follow-up letter to the UNIX tm letters that you
have already published. As the chief initiators of the CHAOS
project, we have faced many of the issues that Mr. duPont and
Mr. Howell discuss. Specifically:
1. UNIX typically interrupts upon every input/output signal.
For example, whenever a user types a character upon a
terminal, an interrupt occurs. The system then stores the
character in a buffer and, later, the user’s program calls
a system subroutine to retrieve the character from the
buffer. This gives the “lookahead” feature. There is, how¬
ever, considerable overhead in buffering characters in this
fashion. Ignoring the memory required for the actual
buffers, in a modular system such as UNIX or CHAOS,
several modules must be invoked upon the interrupt. These
modules must determine the source of the interrupt, locate
the buffer associated with the device, read the character
and place it into the buffer, and finally determine to which
process control should be returned. On reasonably fast
computers, such as the PDP ll’s upon which UNIX runs,
these operations can be handled quickly. On the 8080,
where searches are slow, we have found that full character
buffering entails a substantial percentage of processor time.
Thus, in current versions of CHAOS, only disks and the
real-time clock cause interrupts, and so eight levels of
interrupt are sufficient. We do use a one-character buffer
for input devices, as this permits the system to check for
(break signals) for computer-bound processes.
2. We know of two reasonable techniques for handling re¬
location. One method entails a bit vector with one bit per
byte of program. A bit is set in the bit vector if the address
at the corresponding location must be relocated. Obviously,
this technique will make a program 1/8 larger on a byte
machine.
In CHAOS, we use a somewhat similar technique. At the
end of each program is a “relocation table” which contains
the ‘distances’ between those addresses in the program that
must be relocated. These distances are stored in a single
byte if possible-when a distance is greater than 254 deci¬
mal, a 255 is placed in the byte and another two bytes are
used to give a 16 bit distance. A zero byte terminates the
relocation table. Our assembler has an option to generate
the table, and all addresses are put into the table except
for those preceded by a # sign. The relocation table is
actually stored backwards so that the system can easily
find the start of the table. As a short example, the pro¬
gram segment:
START: LX I SP.TOP
LX I H, 0
JMP START
DS 1000 ;1000._ BYTES OF SPACE
TOP: LDA 65000 U
UNIX is a registered trademark of Bell Labs.
would have a relocation table of:
high
memory
There are a few important points here. One is that addresses
needing to be relocated usually occur far less frequently
than one in eight bytes. Also, examining a bit vector can be
slow, as each bit must be tested individually. Finally, once
CHAOS has used the relocation table to patch the program,
the main memory space occupied by the table is reclaimed.
3. In our current version of CHAOS, we allocate time on a
simple priority basis. Essentially, every process at level n is
given time after a single process at level n+1 has used its
slice of time. Processes that serve devices requiring frequent
but short segments of time (such as a disk-head controller)
are put at low levels while processes requiring infrequent
slices of time (such as a line printer queuer) are put at high
levels. Also, a process may be suspended by the system.
4. The size of CHAOS is only about one fifth to one third the
size of the language (BASIC, PASCAL/S, PASCAL) that the
users are working in. A prime consideration in choosing a
processor is therefore the availability of suitable languages
to build into the system and the compilation/interpreta¬
tion time and space required by the languages. The amount
of disk activity depends to a great extent upon the level of
the users. At our high school, students learning BASIC use
very little disk time. UNIX and CHAOS supplement disk
space with sharable core buffers. This has a major impact
on disk overhead, especially when several users are trying to
access a file, such as the directory containing the system
commands. Also, sharable buffers make filters easier to
implement.
6. We believe that many people are interested in UNIX-type
systems and that even more will be as the word gets out.
UNIX is written primarily in C (see J Madden’s article on
page 130 of the October 1977 issue of Byte and any micro¬
computer with a C compiler should be able to run at least
part of the system. There have already been some notable
successes in transporting software, such as the UCSD
PASCAL and the PASCAL-P compiler.
Our own efforts are directed towards producing a docu¬
ment of CHAOS detailing our algorithms and data structures
so that other users can develop yet more advanced systems
without having to start with the basics. UNIX and CHAOS
offer great flexibility and promote rapid program
—and have already spurred us and our students to create word
processors, interactive debuggers, and even compilers.
Let’s keep this discussion going in Dr. Dobb’s (anyone for
TINY-UNIX?) ....
Sincerely, Clairemont Computer Group
JeffLevinsky 1541 Loring
Robert Haas San Diego, CA 92109
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 3
289
A Compact 8080
Disassembler & Dumper
BY RICHARD GREENLAW
251 Colony Ct.
Gahanna, Ohio 43230
Many important programs, such as BASIC interpreters,
assemblers, editors and some of the most sophisticated games,
are sold without source code listings. Others were written
directly in machine code. When you want to modify or repair
them this program will help you find and understand the
desired routines and can make a source file which can be
edited and reassembled.
This disassembler is compact enough to fit in memory with
your assembler/editor and the program to be modified, unlike
disassemblers written in BASIC. It operates on a program
in memory to produce disassembled source code or a hex and
ASCII dump.
The disassembled source code can be displayed or printed
or can be appended to a file in memory. Labels are formed
from their values in the original program, thus carrying some
useful information and requiring only two bytes each in the
disassembler symbol table. They can, of course, take on other
values when reassembled.
The optional symbol table building pass and the output
pass are independently controlled by the user. Either or both
may omit or reorder parts of a program; thus labels can be
generated on instructions referenced only from outside the
area outputted.
Actual runs are shown in Figures 1 and 2.
Something for Everyone
Any 8080 system can use the disassembler and dumper
(Figure 3, 1165 10 bytes) with the command interpreter
provided (Figure 4, 288, 0 bytes).
Users of Processor Technology’s SOLOS™ and CUTER™
monitors don’t need the command interpreter. Instead, they
can use the routine in Figure 5 (81 10 bytes) to define the
disassembler and dump commands in their monitor.
The basic disassembler subroutine, DISL, is small enough
(723 1 o bytes) to form the basis of a tiny disassembler in your
own monitor.
How to Use it
A simple one-pass disassembly is shown in Figure 1. The
“>” is a prompt from the command interpreter or your
monitor. Commands end by carriage return, not shown.
First we define an empty symbol somewhere in RAM,
at D500 in this case. This uses two bytes for now.
>ST D500
Now you are ready to disassemble something. Labels will
be generated on all instructions because the symbol table is
empty. The following command requests disassembly over a
range of addresses with output to your display or other out¬
put device according to your version of the output subroutine.
>DS D9F1 DA06
During this output the input subroutine (SINP) is called
at the end of each output line to see if you want to pause or
stop the output. The space bar will cause a pause until a
second key is operated. A control( or MODE on a SOL)
will terminate the output and return to the command
prompter. Otherwise, output continues without pause.
If the second address had been omitted or was zero, it
would have been defaulted to FFFF, which would never stop
to output since it can’t be exceeded. In such cases use
controlto stop the output.
The next command in Figure 1 requests a hex and ASCII
memory dump over a range of addresses:
>HA DA60 DA79
The hex part pairs the bytes to make the line fit on a 64
character display. There is no other significance, but it is
convenient when counting across the dump to a particular
address. In the ASCII part, values from space (20H) to, but
not including, delete (7FH) are sent to the output subroutine
unmodified. Others are converted to periods. There is one
exception: the underscore (5FH) is converted because it
would be converted to a backspace by my system monitor.
This assumes your output device handles lower case alphabetic
characters or converts them to upper case as my TTY does.
The method of Figure 1 is fine for a quick search for input/
output drivers, etc., but you can’t see which instructions
receive control from calls and jumps and this format could
Plcrire 1 - A ^lpassenbly with A 0 ?TT/hex r >n’n
> ST nS'T'l
>ns r»9ri nA<?»A
unpin i x i sp , Hr>4F°l
Fnpri cai \ wnsrs
wn9tr7 mv/j p,7«tm
nnQfc-Q r*4l l. wnqrp
H09E-C 1 x I M, Mb ARC
HD 9 rr r:4l l ungro
pnano J7 Hngrjr
un4?is y>v m,a
H nAH A CPI f 10 H
>WA nAAf} n479
Hn a C9S1 sans ns/i* a l n a iiqap siny hvaa sioc . SI • • ha > • ms • *os •
VDA7P 0944 4 All f D9SP SP^ir HV^'1 P4I>'4 DAVE V I '111 . Uh .. AA .
Page 4
290
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
overflow an assembler’s symbol table if a fairly large program
were reassembled.
To suppress unused labels, a symbol table is required to
tell the disassembler which instructions are referenced.
Actually, this table contains only the addresses of such instruc¬
tions.
Figure 2 shows a two-pass disassembly. The symbol table
is initialized as before by:
>ST D500
Then it is built by:
>BS D9D0 DABE
This runs the disassembler through the specified range without
producing source code output. Instead it appends the last two
bytes of each three byte instruction to the symbol table,
unless they are already in the table. This assumes the value is
an address. If it is a constant it could cause an unnecessary
label to be generated on some instruction in the second pass.
Flc-ure ? - rwo-Fft«s Disassembly
> m nvA'i
>RS H9rv* nnor
>ns n9fi
H n 9 F 1 X 1 9P,WDAF'»
Gftl I wnqrs
v\/| n.iru
r./\\ | wngcp
i xi n , Mnaur
m n9k f rai I Mn 9 Fk
,17 wnqFF
V/
PHI ‘inw
J7 MltATT
PPI 7fw
,im7 uda i f
ixi n ,whapf
rail
.IMP wnqri
op x w
> xx
Note that the symbol table should represent all programs
which could reference a label in the routines you intend to
disassemble in pass two. If the range of addresses for the
BS command is not continuous or contains data tables, simply
use BS on each range separately. (Only the ST command
empties the symbol table.) If you don’t know where data
tables are just include everything in the BS range. You may get
some false symbol table entries and you could misinterpret
a few instructions if a data area doesn’t come out even when
interpreted as instructions, but it’s good enough for a first
try.
Note that Figure 2 used the control-@ to stop the output
and then shows the XX command exiting from the command
interpreter to the system monitor.
If you want to build an assembler source file in memory
instead of displaying the output, just use the DF command
instead of DS. You must specify an end address since there’s
no visible display to interrupt. Each disassembled line is
appended to the end of the file, so several DF ranges can be
used.
Source files created by this disassembler exist entirely in
RAM and are useable by several popular assemblers, such as
Processor Technology’s ALS-8. All line numbers are 0000, so
ALS-8’s RNUM command is needed before using a line
number based editor. It renumbers the whole file without
regard to the original numbers. The current end of file pointer
is assumed to be in RAM at EOFP. This symbol is defined
correctly for ALS-8. This disassembler doesn’t use the begin¬
ning of file pointer and doesn’t set the highest line number
field in the file control block. RNUM does that.
Processor Technology’s Software Package No. 1 uses the
same EOFP address and file structure, but doesn’t have the
RNUM command unless you have patched it in. Some other
assemblers are based on this package, or on an ancestor of it.
Operands of three byte instructions are disassembled as
labels consisting of the letter H followed by the four hex digits
of the value. If it is really a constant you must edit it before
reassembly. Instructions referenced only by data tables or
programs not represented in the symbol table may need labels
not generated, and must be edited. Labels pointing at RAM
areas and data tables must be defined by EQUates or other
assembler pseudo-ops.
Operands of two byte instructions are disassembled as hex
constants beginning with a decimal numeral and followed by
the letter H, as required by the above assemblers. Any address-
dependent values, such as one byte of an address, must be
edited before reassembly.
How it Works
The functions of the command routines have already been
described and they and the command interpreter are relatively
straightforward, so this discussion and the flowcharts are
limited to the process of disassembly itself.
The basic subroutine to disassemble one instruction begins
at line 2435 in Figure 3. It can be entered at DISL to produce
a label or at DISNL to omit the label. The HL registers point
to the first byte of the instruction to be disassembled and the
BC registers point to a RAM area to receive the disassembled
source line followed by a carriage return byte. It advances
these registers and if it is a three byte instruction the carry
flag is set and the DE registers have the value of the last two
bytes. One and two byte instructions reset the carry flag. No
other registers are defined at exit from this subroutine. No
other RAM is used except the stack.
7 6 5 4 3 2 1 0 Bit
D
S
OP
N
GROUP
C
RP
OP
s
D Destination Register (A, B, C, D, E, H, L, M)
S Source Register (A, B, C, D, E, H, L, M)
N Restart number (0-7)
C Condition (NZ, Z, NC, C, PO, PE, P or M)
RP Register Pair (B, D, H or PSW/SP)
OP Group and Op determine the instruction name
Figure 6. Operation Byte Format for 8080
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 5
291
The 8080 operation (instruction) byte format is shown in
Fig. 6. OP GROUP and OP represent the bits which are not
dedicated to variable fields, such as register names, in a given
instruction type. An instruction may or may not have a variable
field or it may have both the D and S fields, as in MOV A, B.
If an instruction has one or two additional bytes they simply
contain a number which is interpreted by the disassembler as
described above.
After generating or skipping the label field, disassembly
continues by calling subroutine GTPTR which analyzes the
operation byte of the instruction and produces a pointer to a
3-byte operation format block within the OPTAB table, as
shown in Fig. 7. This block gives us, in tightly packed form,
the name of the instruction, its length and its format. The
7
6 5
4 3 2 10
FORMAT
NANS 1
0
LENGTH
NANS 2
-1
KAf'lS 4
NAME 3
Bit
B.yte 0
Byte 1
Byte 2
FORMAT CODES
NAME 1-3
Letters of instruction name
0 OP only
coded as ASCII minus *A'-1.
1 RP-PSW
2 RP-SP
NAME 4
Last letter of name coded
3 S
randomly for table lookup.
4 D
5 DS
LENGTH
Number of bytes in instruct-
6 N
tion less one.
7 C
Figure 7. Operation Format Block Layout
DISL subroutine then converts the operation name to ASCII,
using table lookup for the fourth letter. Conditional jumps,
calls, and returns complete the name from a variable field.
Then the operand fields are generated from whatever vari¬
able fields are specified by the format code in the format
block and from any additional bytes indicated by the length
field of the format block. Small tables and simple algorithms
are used in these conversions.
The only inner subroutine worthy of discussion is the
GTPTR, at line 3650. This subroutine and the tables it uses
make possible a compact disassembler by allowing OPTAB
to have only 58 format blocks for the 256 operation byte
values.
First, GTPTR determines which of four operation groups
the instruction is in. This is simple -because the group is
simply the left two bits of the instruction, as shown in Fig. 6.
Group 0 consists of many instruction formats so the entire
remaining six bits of the instruction are converted to an opera¬
tion format block number by direct lookup in the GRPOX
table.
Group 1 consists only of the MOV and HLT instructions so
either format block is selected by simply checking for the
HLT operation value, which has no variable fields.
Group 2 instructions all have the same format, with variable
field S. OPTAB is arranged so that the three remaining instruc¬
tion bits are the format block number.
Group 3 is complex like group 0 and is treated the same
using the GRP3X table.
SUBROUTINE TO BUILD POINTER TO FORMAT BLOCK
Interfaces with Your System
If you use SOLOS or CUTER you can use the command
definition routine in Figure 5 with the program (Figure 3) and
omit the command interpreter (Figure 4). Verify the addresses
in the PSCN and SCONV jump vectors (lines 1150-1155 of
Figure 3) and all references to CUTAB in Figure 5 with your
monitor listing and correct them if necessary. Then simply
execute the command definition routine from your monitor.
It will return to the monitor and the disassembler and hex/
ASCII dump commands may now be entered just like other
monitor commands.
Page 6
292
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 7
293
If you don’t have SOLOS or CUTER, use the command
interpreter (Figure 4) and omit the routine in Figure 5. Link
them together and to your input and output routines as follows:
1. Check that the jump vectors in lines 90-150 of Figure 4
point to the corresponding symbols in Figure 3.
2. Point the RETRN vector in line 200 of Figure 4 back to
your system monitor or, if you don’t use a monitor, to
the start of the command interpreter.
3. Point the RETRN vector in line 1135 of Figure 3 to the
start of the command interpreter.
4. Point the SINP and SOUT sectors in both Figures 3 and
4 to input and output routines which do the following in
your system:
SINP: Check for keyboard input. If present, return it in
the A register with the zero flag not set. If not
present, set the zero flag and return (don’t wait
for input). Always preserve all registers except A
and PSW.
SOUT: Output the character in the B register to your
display, TTY, or whatever. This is used by the
command interpreter as well as the DS command.
Wait until it can be done, then return with all
registers except A and PSW unchanged. At the
end of a line this will be called four times: for
carriage return, line feed and two nulls (00H).
This routine is not responsible for pause control
or control-@ detection from the keyboard. The
CRLF routine in Figure 3 does all that.
5. Point the PSCN and SCONV vectors in lines 1150-1155
of Figure 3 to the corresponding routines in Figure 4.
6. Give control to the start of the command interpreter.
You are now ready to go. Try the examples in Figures 1
and 2.
r*i
a
.1
E
r z e z
U Z H C
_J u c -
a u x
i OL > C
u c z
IT c «
V C _! <1
<r i* c z
cr c c 2 -
— x *
c c
s
a
s
cc
■ ir c
cv e
• Lx r- -ID
t- -1 c 3 a.
_J 1 c LxJ £
— c i— r
r i- • x a
a j) u: x
- -I J c -
u c c - ui —
a cc u. a
a i </> in
<!>->- C O <T
r- tr S' r- ui
>- w c
- >• c <r c z z
c i- z -) z <r
a. a uj x u. -
£ £ X m X S X
>- U X — X s u-
cr c d <r s i
T,
iX ’ r-» i—i j| n
■ — U CVJ CVi CV) (/) cv
z x x x x x
■ c — a o o u c
■ lx' u. c o o a c
: cr u c <r c £ c
■ c/ c ^ r —
• u z
x x j: jc x u. x
CL C £• C O Z C
z c- oc c — c
. cr c <i c <r -j c
£ C C. lx f- !
c c c If 1/ i
*»■*•»*
sirsifsifsifs
ir s it s if
sj it ir >£ <
s s s s s
c c cr O' u
uuu»-
u. t- u k u.
x x c r it
c u or e q
> Q IT
cr 7 O: U
- c CT C t-
7 C <j z
’ i* c k- c
<T T ~ Z
cr cr c
cr c £
: u a _■ £
. cr c c c
. sr i- cr c
■Of 7 U
c c -
' c
' li h _
- X <3 C
C -
: 7 u
c u
X
k « cr »- t-
C - it N
v ? C
-Chi
i •“ C
c z
7 * C O'
C £ £ C
h- X
UL W c C'
ii cr h ii
h- C C
1* J?
uc C X h-
Q cr z r
Lt (- X
ix a u z
I- C £ -
Z i*
U X 1
£ l* si U
z c t —
c r t
£ z c c
u
h-
>■ c
c a
c u
a
i- cr a a
b £ £
cr cr — -)
ix cr
c u
H X Z
c c x x
u c i- z
;><ru —
* * ♦ x cr
Getting It Into Your System
The program start addresses were chosen to use RAM usual¬
ly available in systems configured for the assembler systems
described above. If you want to put them elsewhere I recom¬
mend getting or typing a source file so you can assemble it
anywhere. Unfortunately, the source file that produced
Figure 3 occupied 20K of RAM! You can divide it into three
parts at lines 2405 and 3925 with a minimum of broken link¬
ages. The first two parts would occupy more like 6K without
comments and unnecessary blanks. The third part consists
entirely of constants in tables and is not address dependent.
The machine code relocater in BYTE, July, 1977, could also
be useful.
If you can read my tapes and don’t like to type I’ll supply
copies and special editions for a copying fee.
My system is a SOL-20 with 32Kof RAM. My TTY does not
have paper tape. I have a MICROPOLIS™ METAFLOPPY™
disk system but don’t have it doing assembly language yet.
I can offer K. C. standard audio cassettes at 300 baud or at 1200
baud (uses lower tones). The recording format is compatible with
SOLOS and CUTER monitors. I can also send the results of a LIST
command to the tape without formatting or error (CRC) checks. The
software to read this from an appropriate tape interface is trivial.
Prices: machine code of Figures 3 and 4 in normal 300 or 1200 baud
format, $4; same at special address, $8; source file with com¬
ments (20K) in normal formats, $6; same in three parts, $8;
unformatted LISTing at either speed, $10.
Specify speed and format. You'll get a cheap cassette unless you
send one; they work for me. This isn’t a business so there could be
delays or rejected orders.
X — —
— CV)
tx z
-J c
QLi —
XXX
> <r ■*
-p-
s r' r-
CUC
5> s
- <r c r tr- u. x u
> i a c c c_ c
c/> <r x
x _j *
o a x x c i
X c X X c c
-£££££ i £
c c c c c c c
2 o e c c c c c
—■ x
a c
i _
<T
c c
z
<J
£
£
C
C <!
* I
<jxrr<T<iz>rc <rzc c<izc
c _x x c c £ a £ o — 1 £ cc — c
nj a — 3
z c ^ c
“7 a i £
5 IT ? if t if Cif5iferif5ifCifSif5ifSif®if5ifff'ifElf5 if 5 if f if
ififiCifPMCfff-asu^ — c\ftrr<i^ifif'C'f(‘Paa9'a'?5 - — cvcv
— —-— — — — — — cvcv.cvcvcvcvcvcvcv.cv.cvaojcvjcv.cv.cvcvcvcvrc'rrrr
a a u o c
c c c c c
c c c a
c c c c
u
<i
c
> x
C £
<1 V
u i r
a <j
c
c cv o-
a a r-
x cv. oc
ct i^ s
u u cv r «r
oc cc r- — —
s s ^ s
U U lx Lx L. Lx
<1 C <3 <3 <1 <1
C C CL C. C C.
CSS S.
U Lx Lx U U
<T <1 <J <3 «
C C C C C
C C K C C C
U U Lx L L U
C<T<T<I<JC
c c c c c c
c c c c c s
L. L U U U lx
c c c c c c
C C CL CCC-
c c c c c r
L U U U Lx U
< c c c c c
c c c. c c. c
Lx
c
a c u. ix u u
lx lx lx U lx lx
<X C C <T <3 <J
a c c cl c c
lx Lx lx lx lx lx
lx lx Lx U lx U
<r <r <r c c c
c c c c- c c
lx lx lx lx cv
lx lx lx lx s
c c c c a
c c a c c
if CC O' C C S CL
® s s s s --
a: ac a a cc ql a
c c c c c c c
r ^ r- oc O' c
a a o a a a
c c c c c. c.
U 5 - ^ if h
— cv cv cv cv CV
a a a a cc a
c. c c c c c
Page 8
Dr. Dobb's Journal
of Computer Calisthenics &
Orthodontia, Box E, Menlo Park, CA 94025
Number 27
294
X
UJ
£ * O
£ C
C O H *
o <r j c
K C U Ul
— X Z C
x c c c
U Z £
• U. U. c
cr c <t
— ct u u
■ c c * a:
c i -J
e <s u <r
^ II c
u: z
cl a
znit-
U) — <1 Ll L
p tp i/i i r- a:
D
<1
j x _j e
J I / 1 - J Ol I • K
r r x «i c c h u
; Q. j c Q- x a a.
: _> >- —• m u: _j — »-
«JNlZNjQ.Z<J«JN»ZMU.
OL <i
ir r
c a a
-ICC
- c *
r <i a c
a _j ~ (a
< i x r
C C J Q
z
l Iti c ®
U. * % •
Cl £ I £ I £ I
£ -J U.
x c. _j a c c _j
: CT X -J U. <3XU^X>X—x—Q.Q._lC»-
’ - C C - C H c CZCZ^»Z>CC<TZU
aaxo “5 xo£~£~£-.£Q.a.c“tt
I Ll x x
CSO-ICI/ 7 CCX
: c o « x x
_j x a: <r — a x nj <j x a.
: x o -J C X IM £ ZZCZ£
; — 1 x a _< c.' “j c' — -j - c'
siruirsirsirsirs^sirri/'Sirsirsi/'Sirsirc'i/’ffirsirisi/'Si/'Si/'Sirsi/isirsirsirsirisi/'F'irjri/sirKir^irsirsi/'sirKifs
ocxo'^ss — — cvC'c r rsi^iirirX'cr~r^cDXO'»'®c — — 0Cvr'r , '^^iirjrx\£jr , ~r-xtte'9'(5'(r — — cv.'Cvr'r^j-giri/'X’xr-i^xxa'O'KPf — — Cvclp"
xxx xr^r~c'~r'~r'r-r-~r-r~(^r-r-r'-i^r-r-r-r-r^r--cLac cc cc ctct iinxctiiicciixxttixij'jf'jj'Uff'jff'UO'j'cr./'O'j'j'j'ff ©'KK 5 5 ?■ S
-— --— — —-— — — — —-—-— — — — — — — —-—---— — —-— — — --— CV.CV.CV.CVCVCV.CV.
c *r - c — a
c u cl c c u
ace c'i*-<s<*‘xr'Ccoc*'a
c a x <j u <s c <r x <j ^ c - it c CLirac < a. rt-^rxrx — — c cv ^ a <x a cuccr-cvcrc
c c u c u. o ccu.cc c s c c cuuc c u r-CLr^cv-ncLp-ucccc u cl u — u c a — c — — a.
•ff'ecucL^iTirxacs — — — •5f' tt 0-ffuu®r‘(rxxr^r-oc.a<jacus—CLirttao'»'0'a'a«xcuuu — <;i/-xo-<ra
r<i<i<i<raaaaaaaceceecccccccccccccccccccuuuueuuujuuuuuuiiuuuuuuue
:ccaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
rrar»cc<i<i<rc<i<i<i<i<iaaaaaaaaceeeecccccccccccccccccccuuueeu
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaxaaaaaaaaa
cccccccccccccccccccccccccccccccccccccccccccccccccccccc
LIUUUUUUULLUU UUULLUU
ccccccccccccccccc
x 3 x _i x c !\
It " li “ S !T »
P* U if U CL c <3
c — 1 c a
X S- f-_I
- * r x c
xxxcccx ac cex
W t/' z
tr a ii j
<j c c
a c x -
- c e* x c a
H -I e-CHCI- h- K X
i <r- k- 3srsrerr uj o
* c z? x»c»c-cc u •* »
) x a it x a c ctt^ovDi/'^ x <r —i c x
x x _j a -i> —• x
<jxxx.vi — <r a _j a — c i- c _ _• — s
»-ZZCZ>^CCC<JZU C <3 * z
— c r £ <r a c' a c “ a c cc _ a
a?>-jaxa _j — j — a c > a. > ai
JCC<ICZ£ <T^»C-<TZ><J£ CDCX
' X £ O 0. —■ "3 C' £ C £ C £ C “3 C £ {/> £ l/'
s it e u* «■ .r s
r r- 9 if if x
r c r- c r-
ifSifSifSifFirsiff iffifj'/i.ifTifSirEiffi/ifs
xr-r^oc a a- O' r <r- oc\rr ccirirxxr-t'-ococo'o-ff —
ifSif?ifSif®if 5 if 8 ifSif'SifSif 5 ifffifEif 5 ifR/ 8 if 8 ir
— cvCLrr-Q <jiriirxxr-r' 0 ccc*'*'®s— — c\ cl <*- r ^ if if >f x m'-
ififififiriTififififififiififififirx xx x x xxx x xxxxxx x
u r* e r* c O' a
M' if r O (*■• CL
u cl e <x e cm u
u u u. c u u. r
arrifMiCL-c-CM?
sso. — crsccccec
C C - if if
c c c c e
— <1 CL —
e see
c - c cv. r
c c c c c
« u c »r r- c — r r
e u. c e c c ® c
r'cxcxcxx
eff-esuffue
cxcxcxcp-
c s c s c e. c c
uccucL-gp* acffccsftr^UuuuiiOifttffocccc u e - <j r-<xae-CLCLCL<\cvir'pirccr<rceucLCL l rt'-<reu-<jt-r-r-ct*<x
o cl cl cvr r r rrrrr^^^^ < i^<!^^^'<iififififirififififif'/'£x xxxxr^f~p~r'r-r-r'r'r-i^i^ r~('-r~ccccctccccix a^9'U'0'W'T-9-tr a
aaffmaaacaaaaaaaaaaaaaaaaaaaaaaaaaaaaa aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
ccccccc c ccccccccceccccccccccccccccccc ccccccccccccccccccccccccccccccccc
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
'S' I—
? >
— ir
C x: X (S
P _i c p u
j. _i <r c
x p x p
— u' — c <r
y 1 c ^ ^
~ c x
c c u p
II u. C
c u : -
I C <1 c c
H- C
u x
p —
i w- a e a a c r — •
r x
a. i-
r- I/ -
Z' P
y y a i —
#**♦♦* c
tsysytsyejycysy
x oc » o> 5 5 - — cv o c r
cv&(\(\c\cvcc.accvc\
cLOLcc—c<r* a a o <s
c <r ® c
i a c u<i a x a
C Q
o <r ii
a a a c c
a
c c
x a
_? x x
_ <3 —
C X C P
x c -J <r
«- <T X X <X
C I- P z c
C 71 — — _J
•- — <T
P *NCI-
<r c "3 <r y
X XX II XX
X X <J — N--<JXC-UUCK« 1 -C>*-C><IX C X X
PPCPP^CJ-PCP-J-J-J^DXCC >cccc KPC
- - j <] ") i <Ttr — _j<to:q:ce: Q._j«-pp<rp _• a.y*-c
CL
a u x
X C <T
X Q- c
C C »
CL
c c
— A
3t - l
x. y
o ~
I U! i
spy
u. <j x
s P
i
IS) X
X II
C CM
— C *
p x ~
x p
•i s <r ^
y u; j y
X S CD X
• y
</) -h rsl x
Z> X p c
X o o x
- a — x -j
c * * c *
ye a - * y c ifpirsirsirsirsiC'SirsirB-irsirsirsi/'sirsi/'sirsirsir
i y y Nt 'tc^r-xtta'O'ss — — cv cv y r <3 ^yyxxr-r'-ctcco'O'S® — — w X r r
i <i <: n <3 <j <j c <3 <1 < 3 yyyyyyyyyyyyyyyyyyyy>>c»c x <c <c <c <c
C O 0 CV CV CV M X W X X X X CV cc X Oi X W Cl CVCVCVCVCVCVCVjCVCVCVCVCVJCVCVICVCVCVCVCV
®ysycy®ysy®y®ysys
^<jyy'CXP'p*xoco' 0 'S-® — — cv
'i. O' c c u-
IT iTlC IT if < <1
x x x c x c x
c c C c c c c
< >L X
x x x x
c c c c
c y c - c <ixxcv.rr<rx <r'ccvjnr'flx>cviu'£cvr, c'fcp-r^i" y — — x x cc y <3 — cv r a a. ^ * if u ^ -
C X X X X — X X « ® --U CC®®--lt'CrcKS-W5SS CSK<irK^ 8 CSS-- — X XX C u
— <3<3yctff'cxcx—cvr<3yp*p‘<Txoxx®cvyr-0'<raxxxs — — cvy'Cr' 0 -«axcxus — — — cv^vj^yr^c
* x 'L'A.vL'f'A.x^xr~r'r-t^r'r-p'r-r-r-p'r-ttccccttttttXXXtta' 0 'ff'aa' 0 'a'a'XO'a'a' 0 'y<r<i<i<x<r<i<r<i<r<r<i
X XXX X x x u c c c c u c c c c c c u c c c c c c c o c c c u c c c c c c c o c c c c c c c x X X X X O X' C_ c x
“C C C C C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCOCCCCCCCCCCCCCCCCC
y x <3 —
X X c X
x c
x p
p —
X p oa
-i c - <r
cd a x i-
<T C
*- P X
C X C
-J X 7
c x - c
y c c s c o x
X o
p p
— c
X c_'
x y
c
: <s <r
<Si
£
y y
y a
<r c
u i _>
c
s
»
s
<s>
a xa cxKcaia;ciia a a
a a a a <r a
i c
<T P
a c a c <_ c
a a ? _i
<r i - c
»- _ p
IX —
* c
PC • c c
c u <? y
a h p
i- — <»
VP X _
p — c r y
— _x —
x u _• C X
rv- c_' t— x a ix<r — Xfl\i- y _j
ZI-XPZ CPCXCCPX’ <i
rjya--: u - juc jti c c
p
X > c PC X
y p p — i x
X
c__
C Z I c
c c a 2
2
<J
i
p a
C —II XXXX X
_ z> z> a. yyx — <jx<jx<ix<xx— c
c c »-rrz>H?i-?i-?i-?>h
paxii — £y — y — v — v — i y
x
* c
y
y c
y®ysysy®y®y®y
y'A.yr^r^xcc^occ:^--.
ssscscsssssss —-
CL CL CV CV CV.CVCV CV CV cva CV CVCV) CV CV cv
# * c c *
<sv®y'5V5yg.y® 4 /‘®ycivsir(sy'Gysv®v®yc
CVjcvyr"^<jyi/-\ANCf^P“ttxa'a\c® — — cvcvyr*^^yyx
---CVCVCVCVCVCVCVCVCVCVCVCVCV
CVCVCVO CVCVCVCVCVCVCVCVCVCVCVCVJCVCVCVCVCVCVCVCVCVCV CVCVCV
—< —1 X X ^J _X»‘_'I
aax_ y
zpc>t-c»-cKcZ'i-c<jpx i c a c c “
^xcpypypycLyyxc-.x x _■ <r c_• ~d a
y v ”
y y c a
<T <* _ l -
y y *- cc
—ray
C CD —
* * * * * C
irsvsysy<sir&visy®ycy®i/-sysv
'£r~r-ococ 3 ' 0 '®®.- — cvcvyy^<jyyyy r-
Ci'ClCiCiaciicvrrrrrrrrrrrr r- r~ r'
acvcvcvcvcvicvicvcvcvcvcvcvcvcvcvcv-c cv cv o o cv
a
c
a
c
a c x
c c c
a ®
c c
c ® s a e
c c c c c
x x
x x
X <J V O' x
x x x r- x
C p*
O' ®
® x — cc r-
cv <3 s ® s
cv p~ o r r
c r c - c
r <j x a <r cv v
-x-cj c
c cv x p- y e-
c a r r- cv r* c
c -
<1 ^ u
y y r
CCS
ucvrcvrcvrcvrxcv
yssssssssys
r cxcvoocvvcv — —cv — ccvy
® c t*> s p* n **• r c v ® c c: c c
a c
c c
a- —
x *
c c y
c c x
X
a
c
X E
X s
a c
c c
c
c
cvyyyxr-v^a.xxxx
S®SSSSS®ESESS
X c c c c c c c C C C C CJ
cccccccccccc c
cvyr-a vca a axxcvy^yyxr*x«accu
----— CVCVCVCVCVCVCVCVCVCVCVCVCV
X c c c c c c c X X X X X X X X X C X X X X X X
xcccccc cccccccccccc ccccc
x ® — cv <3
cv r r r r
C X X X X
ccccc
y «c ^ a x
y r: y y tr rr
xxxx x x
c. c c c. c. c
c s — <3 y
r <i <i vi o
xxxx X
ccccc
< r- oc a u x.
<1 51 C <3 <3
X X X X X X
c c c c c c
xx x x cv y
vi <i <3 y y
X X X X X X
c C c c c c
Page 10
296
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
X
x t-
w c-
I- 2
tt tt! II
i* O <
u.' c e. c a
h j u a > u
>- tt a u. u
a: —' a t- t- a.
u. I h I/ 1
a. u u c c
c ^ c j h
— y
h- 2
<1 —
<T —
X lx.
(x UJ lx)
I- I X
c •> u y ^ y
ccGCcwcf'acyaaQ.ciox: o. o o
— <x c c
K 5 i t' I
>- u c * •>
a s c <r ti i cv
<r cj <3 a <r
i s li li
tt y a a:
f* s < i m
<3 X Q.
1-2 2;
y — -5
> j i ,
C «I C 3 Q_ I
2 e x a. c .
A U.
X _) _1 X X I lx. X X
<rx_ji:> — «j<rr<rxQ.xxxixiiiy<ixeoo —
l-2<TCC2<rCC?t-2CC Z 2 C 3 a C _J _) _J 2 Kj
tf' w CliIflC.'JUC/'N'llLw-H t-Q..JQ.QC0CQC^3
a 3
A 3
H C
2 A
5 Z> <T — K > I> X — ?
c r-C*Xrvja 2 CC 2 X 2 -H
2 iic"5CC22-0"3
e, _j c
> X X _J X o
C ZCJ<XCJl-
2 •- x o x y>
— <J Z> CJ -* — > x
>HC£H2XC22
2y2X<JC2”)-
o
<1 cc
y e y s y
CM CC O' O'
5 K C S 5
r r- r
y®y«sy®y>®y®y®ysy®y®y®y®y®y®y®y. ®y®ir>6rysyffye:y , ®irsysy>sy®»r
®--cviwrr)<i ^yy'C'C^r~ttJ®0'0'®s — — cvjwncr-q •qyyvC'cr-r-occto'O'C® — — xxr“<r-<j'9yy
— — — — — — — — — — — — — — '- — xxxxxxxxxxixxxxx x cv c\ cv cv rrnrrrrrnrrr
rnrnnrinrrrrnrrrr'r'P'nnrrpinnnrrrrrrrrrrrrrrrnnrnrnrrrr:
sy®y®y®y®y®y
'C'£i^(^ya O' O' s s — —
r'r-r-yr'rr'r < 3^-<J<i
rjr'r-r’nr'r. r r r r, r
c
c
c c
c c
c
c
o
c
c
c
c
c
c
c
c
c
a
cv.
C £ 00
t- c cv
CJ
£ r~
<j £ i" cv. f-
■q tt s y
0C
c £ u & y
< fr r* y >c
cv r r
<S 5 CJ
<r c — y> uj <r
r- cj i* tt tt —
cvirrc u . * c <t cm r ^ - r r
®®c_ Mi u - s s u. c cv -
y<r — f^f^t-'£« 3 Lx
ii-cssst uir
<r r* <i u <5
r* a. c u c
a u. r u <x
f" y x tt tt
< r cc c cc r-
y cm u c tt r
r u.cv.a.u.'cua.cfo
c crst-sixU-r^u.®
a c c s r s — oyvcao'oc
£ £ £ — —-.-- -
CCCCC CCCCC CCCC
CCCCCCCCCCCCCCC
C ll - -ft^l'KKO'ClIL'Clil
- XXXXXXXXXXXXX
ccccccccccccccc
ccccccccccccccc
uujix® — a r ■q »c O' c c tt c u
WWCMrrrrrrr.rrrr r
ccccccccccccccc
C c c c c c C C.C c. c c. c c c
— -q y r-~ O'
<i <i q <i q q
c o c c c c
c c c c c c
cj c c
<1 ^ <1
c c c
c c c
u ix cm r
<J <J y y
CCCC
c c c c
•q •qi^r-O'ca.ctt®— <5
yyyyyyyyy'C'C'C
ccccccocccco
cccccccccccc
c a
_i
2 —
C 3
X T
lx
X
y <r
c >
_i i
lx x
-H C
lx
c n
C 2
2 ~ tt
X X
tt 3 >-
— C I-
-J I 3
x ® y
c c x
CV 2 2
y *
x y <r
a y y ii x
r- C X X y o o
x y y
a <r cv.i 3 j a a •
a a 3 -* y y ac a »
<T'CC'Cxyxxxa<iaa
x
- >
3 C
.• <r a. x <r a. x <i _j
c - t-
a ® y
<1 * -I
c\ c c
' c
■ X H C
y — y
M Z X 3 I
3 0 . c x '
> cj c cj — z> x y c > cj — J> —■ m x y - „ . _ ^ .. ^ __
,> iv n. ^ ^ ,r. ■, 2XcZXlv^t-2>2>K2>H2Z>2
xorazcczc
attorc2Xxc
X2 C2Ch.«ix^_lxiv-'|-
3t/)2<'2 0“5yxxcj“32y
cx*—a— <jx — <jx—<o_
2>l-2>h2>-
~)2 y — 2 y — 2
*-• rs/ y ;
X 2 X <
■ c 3 w ;
rv 2 :> CJ
2 C C
3 - 2 X
y ® y ® y ® y
CM 3 r> -q -q y y
i— r- i—
CM CM CV CM' X CM CM
: y ® y is y c y®y®y®y®y®y®y
r-p'ccyo'0'®.® — — xxr'r-'q-qyy
:y®y®y®y. ®y®y®y. ®y®y®y®y®y®
:r»r‘oci^o>sc--cvicvirr)q <qyyy yi^r^a
■ u.ixu'tj'c-'C.— — ^ irif 'i x i'^CCtta'0'C£--CViCVir(*l<I •qyy'C >1 M' K I f (
l'-l'*r~r~t''00XCCCCXCCXCCCtCCCC.(X(X0C(X0t0Cci.XCtO'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'O'<
X X CM XI a CVJ X X CM X X X' CM X CM X X X X X X X X X CM X X X X' X' CM X X CM X X X X X! a X X X X <
X
UJ
U. 1
-J
c
u
u
a
c
c
2
u
ou'U-coccaacccaa <j
XX XX
•— cj> — c><r<rxx<ryx*-
X C C > C C CH22CI-2^
—'<3 2 2 <r 2 _jy — — _jy —2
y®y®y®y®y®y®y®
C - Oi X r (Mi -q y y < sf r-
ss®®«®®ss®sss®
rrrnrrrrrrnrrr
c
c
c
c
c
c
c
c
c c
c c
c
c
CJ
X
® —
<J X
r* sc <. £
U G £ —
£<rr~ £ tt. £ r- r- cc
•qcy yxy y yx
cs x
c u.
£ tt
r x
S £
U —
u
u
£
<s
K
X
<r y u y<r uu.u.u.'ir^ — y
l c I* it c i^sissuyuu
auu. — xyy'cr-a.O'accu
c<xcaaaaa.a;a:acLa:aa
C_ CJ C.' CJ C c C C CJ CJ CJ CJ CJ CJ CJ
ccccccccccccccc
x <r < r~- u a — y tt <r
c u. y u c u u. u cj
tttt — — x ^ y r* < « a c tt
a a cj c cj c_- cj c cj c cj c c
cj c cj cj c c c cj cj cj cj cj cj
CCCCC cccccccc
ttXMirttftrttXr.ttr
rssrcrssrssrc
— r , 'qyf^<rcCtt«s—x-qi^r-
CCCCOCCCCtttttttttttt
C CJ CJ CJ CJ CJ CJ C CJ CJ CJ c CJ c CJ
ccccccccccccccc
tt X <3 c- tt X C r-
tt c 1^ CJ CJ tt CJ p“ s
p~f^O'cccttxxsir^r-tt
tttttttttttttttttttttttttt
CJ CJ CJ CJ CJ CJ CJ CJ CJ CJ C CJ CJ
ccccccccccccc
— cru-tt;cr''<ixr'r<TXrtt
— ttyrty- ®s — — scr
O'octt® — xr-^yxr-a.O'
tt tt tt tt £ £ ££££££££
C CJ CJ CJ c c cccccccc
cccccccccccccc
Number 27
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
297
-1
QC
<1
CL CC
c <r c s
o ~ o c o u u> <r c
u.
o -J zNzciio.1 a c x z u. o •-
d X X M O C U C L. J <1 U-'CC
I • “ * «* ■ • ■ " * “ * * ^ * * - * L' > li.' - C\1 n <5 t
o ~ c
c ot
u uia:
_ o c
' 3 _ _r 2 kD2D2:
{/) OC?C?<3<
doduiocccdoccucccc — » ir w ui u u: i
*- _i
<r x c
qd a. q: ui a.
*- H DDL
d C 0. 2 >
I 2 U. C •— C/> <X CC O O I
o x * # * c ir u c i
o c c c *" a - —
z x a a: 2 s ex
“) CM X X Q: <1 T) U _)
irsiTsifsirsifs
'C^t'ttiCCO'aSG-
f^r-'nnr-r^r^ccctcc'
mncrrirnr-rmr!
u. t-
x c >
- c>«o><r - tt —
2 C C > d C d ex x
<r <r z z <r z _) u u. o. _j
c c
2 A
X — I
Q- X II J
- H- <T I
* C
_1 * c * *
irsiTisirsinsinsirs
- a a* n r ■‘i <j in ir xxr~
CCXKOCCGOGCCXOCOCOCX
otrrwnnnc'inccrr
7 > C C (2 > ~ C
-« c ccoc ;> e •
i <i <r <r i r <r
n" s ir 5 if e ir s i/i sirsi/'sinsirsiririnKirsirK if^ifsirsirsifsir
or cc O' O' © s — cm cm n n * ^ tr m x x p- r~ oc ccc?'Oes — — c\ cv r r 1 <i <j ir if
UlftCC([r(MMMMMMMMMMMMMMMMMMMM S5SK | SSS ' S f : i5 : .
r r r r r rrrrrrnrnrnrrrrrrrrr^ <j ^ <3 <3 -q -q
® cm n 52ix x O'
1 0 e e c* e e e
: ui u' ui lu uj u 1 u
o ji zrnaif
• ~i j 2 71 a. a x
iff'lfKlfSlfSifKif'SifSif'SifSifSfSlff.lflfSlf
>cM'ciC(M>5'5;--c\a i rr<j <jirirxxr-'r-ix;»0'(sjs
cv w r r virif'*-'tri'CL»o'B 5
ssssesses'sesscDS — —
cm a. u. u. x r: — x r- u u <t t' c —
C S & 5 It! c — It' k im if - —
5Tr»notO'<rou.u.u cv,<iu-xoco'<raa.a:aL(i
o o o c c c o c c c ccccccocecdc
CCCCCCCCCC CCCdCCCCCOCC
cccccccccc CCCdCCCCCCCC
cl 5j oc c
<3 <1 <1 5J
— u. — — r u. u « r~ <> ® t*- o u<r ur'sssc cl ^ oc c
— ^ CO tt 1C if r. 1 if C CM <5 <1 ^tT5j^t/ , 'mir^ q q q <I
ce uu.u.®.-cvnu-xc'‘Cccccc<cuuscM5jxcc<reu.uscL^xxxxxxxxxxxxxv©xxx
£ CCCU-UUUUU.U.UU.UXU.UuU.U.U.UU.U-U.U.USSS'SCSSSSeSCC. CSSSCS<D<S<S1CS
c ecocccececccceeccccecececcuuu.' uiu’ U-UU.UU-U u u. u. u: x uj u. uj ui
c ccccccccecccccccccceccccccccccccccccccccccoboo
H • n X
> I Dl
ac - « s :
X •> « <
x <r cd 00 <x h <r .
x a j 3
•» X % IT
1 x <i x <r a.
2 3 x • - 3 • 3
xw uso«c<rc
ICLS* • - _J
I o X CC H H
® X X % c c
a o p“ <r o c o
-J — <TX<I2»-*
<r > H 2 QC c >
c £ <n — x l. z
a. *-> <x x h-
£ > K 2 u
3 Iif Hfl:
• - O > H
>ocui
z <i x a:
:x> j>tf!ccucja-«« a.
■ 2 C <T C C 0: 0: 0: 0: <r c 2 d 0. O d Z
l-ZOllLttttaKolfl ■)
-* X Q. «
X > N 7 Z X
• O Z 3 - 3 o
SifSifSiflSifSlfSiflSifSifSifSifSifSifSlfSifSif.
w w n r <1 5iir'ir*fi>xt^p'xx<>a's® — — CMCMnr?5j ^ m ir x x
<j- | *5i<3<j-<j<r5i5j'q<*-q<j5j5j<j J r l /-)ir. ififififififififififif
ifsifscfsifsifsifsifsirsifsifsifsifsifsifsifsifsiifsifs
cm n n 53 ^irwxxp~r-occco' 0 'S<s — — CMCMmr>5j ^inmxxr-ncccco'O'S
iriDmtririririr'criPiririrtrirxxxxxxxxxxxxxxxxxxxxr^
r' ff m fo r*' rri ro ^ rr r* *c ^ m ^ ir> kt ^ m- ^ ^ — —
X X >1 N N -V N N N N N S 53 5J <3 flfflflflflflflflflflf l flflfl/'^|/'|/>^^^^^^^ l£ X'C\CX'C'0'C'£X'f'vfX'C^
nnnr'r'nnmnnnnmrrnmmmnnnnnnr'nr'r'mnomnrr. rrrDrnrnnnrnp'nrrrnrr'nr
— c CM
ox cs
x o x
* o * * c
s — — cm cm r> O 5J 51 if If x
t^r~r^r~r^r~r-r-r>-r~r'-t^
rnrrrnnrnrnn
d u. a r u. uj n
o r s s <1 no
If K < ff OCCU.
xxxxxxxx
cceccccc
cccccccc
ui &i r O'
n ® <s o
— r u. u. <1 r- o'
— a ir n co if o
® ^ a u. s <t -q r~ scuq
5i (» 0'®mnr-®p' <ia.a
LC\jrcDDifitU.u.itc - x x ui <r x n ujucm —
rKS^uMtssMSScititUitcuu r- u c —
xooo'<iodu.u.s — CL>n5ir^oc«jou—nxxxxxxxxr-o'oo
ttlCCOXICICICO'O'OO'O'lhO'^O'O'tfC^C^^tfCtf^ddd^
CQOCCCCCCCCCCCCOCCCCCCDCCCCCCCQ
CCOCOCCCCCCCCClCeCCCCCCDCecCDCCd
n u- cm u. u: <r o n u
c it c u.nono u.
U.CMCL5jr-t^O'XU.U.CLCM
<rccaaa.xa;xffaoo
ccceecceccec
cecccccccccc
Page 12
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E. Menlo Park, CA 94025
Number 27
co
n
x
-j
0 .
x co
x _j
X _] X
a: _j x
CC O'
9 IT
II II
<1 <x
O H-
-J CO
co co
_J -J
♦ ♦
_J O <1 tO »-
-J O <T to H-
C 1/3
9 Ql
' _ a:
•i ®
X CM
<r ••
CO X
o
X
X <0 X
9 0 . 9
_) UC _)
C X c
♦ + ♦
D <1 (/) h X
c <1 CO t- <1 X
CM
II
o
c
o
9
_J CM
C -J
♦ ♦
o x <r a
e x <x o
CV! r 9
CM CM CM
II II II
era
<x to in
CM CV CV
— 1 —I _)
♦ + ♦
cc-i/r-t/a
tfc-irr-i/ia
IT
ii
X
Z
■x. i"
CVJ CM
II II X
X O CVJ
o <r ii
c c <r
o
O'
CV
II
Z
<r
in n
x x
xx cv
XX _J
♦ ♦ ♦
zxco*e<icc<r<r<iz
zxcoxc<co<r<i<iz
s
r~
ii
x
X
CV
X X
X X
r~
ii
cv,
_)
♦
c X
c X
X
CO
II
9
CO
II
O
X
X
m
co
n
_)
9
X
VC
CO
II
X
<x
X
_)
♦
OX~X_]Ol*Xe>X<T_JX
ox«-*x_Jo^xoix<Tja:
axxxxaaxa
QOOOOCOCC
x a a
c c c
a a: cl a ai cl ao ai cg cc cc cr cc ao
CCOCQCCQQOOQDC
xx x a
o o c c
a xaxxxxa'xxxxxxxxaxxx a a a a a a a a xxxxxxxxxxxxai
cccccaooacooQooQOcaccocccccccocoaaocoaoco
ITS/ISI/IS/K/
'dhM'CCO'O'ES
99999991/llT
999999999
S IP K IT S / S /l
<-cv CV r r' 9 9
iPiPiPiPiPiT'i/iiP
99999999
SlP®iP®lPSiPS
iotr>' 0 'Cf~r»ccocO'
iPiPiPiPiPiPiPiPiP
999999999
iPSlPSlPSlPSlPE
O' 5 5 — — cvj cv) r- r" 9
IT'C'C'C'C'C'C'CC'C
9999999999
PSlPSiPK/S 1
9 IP IP >C >t M' X
vt'O'C'C'C'C'C'C
99999999
IPSIPSIPSIPSIP
X O' O' (S ® — — X CVJ
999999999
SlPEiTSlPSiPS
rr<!9/p^'£r'
999999999
iPSiPElPSlP'SlP
r^xccO'O'®® — —
c^p-r-r-p-xxxK
999999999
CVJCX 0 'U 9 -'-C 09 ^OCCCC 0 XCJU 9 — (0 9 - XCO
-----T 0)-9 0 ! CViK«CO-C-K
w U a; o' U n »■ n v - u n i
-Mlf KS<T®« ITS S 9 i
— %* vsoiSBWs-ns-wsftS-wtt-w* v> » »* » - ».*»«. n »
cvjco9in'cr'XO'cxocx , x® — cvjr9i/3'fC'xo'<rxcjcxxx — xc r 9X'C
99999999999999 IT. iPlfl/miPiririPlPlTlP IT. iTlTlT, 'C'C>0'£C'£'£
X X X X X X X X X X X X X U X X X X X X X' U X U XX X X' X XI X X X’ X X X X
UL;nu.a-wn^w. x,l'ttO'<iaiUCUIXB-
CV]OJCV.CVJCrCOCOCOCOCOCOCOCOCOCOCOCOCOCOC09 9 >i n -n >i >i >i n -s -x -N N ■M’N >* u. u,
X X X X X X X X X X X X X X X X X X X X X X X' X X X X X X 1 X X X X X X X - X X *»- —- •»- t*. •*
DDCCCCODOCCCCOODCCOCOOCOCCOCOCOCCCOCCCiDCCOCCCC
9 if'Ci‘CC 0 '<iacc
------ _i'i't'C'C'C't'C'C'C
X X X X' X' X* X X X' X U' XX X XX X X XX u. ul. u. u. i*.
ccoccoocdcocccccoccccccco
X ® — CV.'
x r- t- r-
X X X X
i i a. x s
• W 9 ®®CCVJ 9 'CCVJ'C
JCVJCV CVJ 9 CO NC O' — —
a s cv.
CVJ 9 NC cv < O'
CO < O' — — —
u u-
rz’Zc ddu:D3dd2>-d:d:dd:
■C?O(jOC?CC200OC?l-OC?!?e{?GC?
.XX X X X X X X X X X X X X X X X
Z ODC'I-JXQCCOX
X C 99999 CXX in
:>x_jcvi<oox-1-J_j_jxxq:v)cc2c
: 3>X*_I_J*CCCCC *xxxxxxx
-J c
on
X h- C
- c 1 - o
r <r z a
- C Z -I X
: X X Q
a c x c
l c x i- o
o m
b’ to z CO
JlO-<««
— to CO
x —
I c x >- X
c cc c.
: to
3 I- to X (O
— H c I-
] CL •-* —
CL >c CC
lO
i coa: jcc j
to D
»- o
-- <r
co in co
■II-tOH
. C* X t- X
) to to to to to to to
X X X X X X X
♦ ♦♦♦♦ + ♦
raa<taoior'Citoa:aj<rz<rxx<rcQc<rozx
[OD 9 :oocoz'QDtoa;DD<r 2 <rxci:<rc a: <r o z a.
X -I H- I
x -i h r
ajccccajcQcrcrcccrcLccaDCctrccGceLccircccoccccoc m cc a a
CVJOCOQOOOCCCCOCCOODOOOQOOC — CJOCC
0 .
o
c
a
IS.
c *******
a.
D
C
X
IS
c >
? z
<
X C I
s x
X +
> oc z
> r' <s z
o z
z c
9 X
X
a cc s a
o c to c l
<0 X
^ - c c ^ - z
3 > ^ O O X « 2
SiPSiPSiPSiPSiPSiPSiPKiPSiPSiP. SiP5iPSiPS^®iP®lPSiP®lPS'lP8lP®lPSlPSlP®lPSlP(SllP(SiP®lPEirKlPSir'SlP
— — CVCVJC0C09 9lOUO'C'Ot^r'KttO'0'S(S«- — (VJCWC0C09 9iniT'0'Or-t^(X)000'0'®®^-,— CVJCVJC0C09 9lOlO'0'Cr^f^XCOO'0'(S!(S—'-CV.0.
— — — — — — — — — — — — — — — — — — CVlCVJCVJCMXIOCVJCVJ CVJ CVJCV1(\JXJOJCVJWWCVCVJCVCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOC09 9 99 9 9
9999999999999999999999999999999999999999999999999999999999999999
5 IP S P S P ®
co r 9 9 lO lO 'C
9 9 9 9 9 9 9
9 9 9 9 9 9 9
— 9 9 — 9 COCOIOCVJCOCVJCVJ — X — CCCM — XCM — COC® » O 9 C X -C
'£5S'C®Sf'-®f'SS'tKlSr--S'C-®'£iS-. <S CS — <1 (S —
O'C0'9C0CVJ0'U
(ccosccs-oos
'C'C'C'C'£’C'L'C'£'CiC'£'C'C't''C'C'C
xxxxxxxxxxxxxxxxxx
DQCDCCOOCCCOOCJCCOC
»c «c *c »c
® ® 5 ®
X X X X
o o c c
'C 't 'C
® ® ® s
X X X X
C D C C
'C vC 'Ll vC
0 5 ®®
X X X X
O O Q C
'CMCff,<MEOC
® 5 5 ® ® ® ® 5
XX XX X X X u
CCC OODQC
XX 8 -Wn 9 P't
o® — — — —— — —
xxxxxxxxx
COQOCCCQC
x O' <r a: c c
xxx x x x x
c C o c c o c
XXX® — OJC 09
— — — CVJ CV CV CVJ CVJ
X X X X X X X X
caoocooe
9 9 lO'Cr-XO'^CD
CVCVJCVJCVJCVCVICMCVICVJ
xxxxxxxxx
CQOCCOCDo
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
299
co
U. k. Il II U. Il II
x ujx u x it x uj o u c uj ui
— <ixixa: — oaocxococ — tjc*-<rxQ:Q: — _)oc«:xa::E: — oco«_jxa:a: — <rcc_JxuaLt~<xo — <txaco:—oco<rxctQ: — c
XI-ZZO>-JZ<rOOZO>aL2XI-ZZe:><X2<TOOZO><r2XI2ZC'><l2<j:iC_'ZC.>ZZXl-ZZo2>l-2<rCCZC.'>£
_ji/)-- — azacDo-Ja — cio:Djifl'-«c£ii: 2 ojo-< oza: d jvi — «-'CZcrc_)c~czo 3 -Jt/>~ — o z i/i : o _j c ~ c z c
CL
c a. a.
a c z
o lc m u
co O' 1/1 cm — acor-r^X'CCM — s^-c^irO'ircM—®t/»
— —cu — — — coi/icm — cm — — — r>ir.-a. — — —
acrcccLcociaDcccrcctiacracaaactaaaa cl
CCCOCOOQOOOCCCOCCCCCCCO
®ifl®in®in®insir8if's^si/'5if 1 ®if'5 , i/'®
r- cc. co O'O' ® s - — cv w n n <i cirirx^r-t^cc
— -— — — CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM CM
i/ii/iiri/ii/ii/ii/iir. i/ii/ii/ii/iininiri/ii/ii/iiririr 1/11/1
r-r-cO'CCM — ®'f'f^cnf“iTCM — ®Kr^r'>C'LCM —
ITCM — CM — — — COlT — — CM — — — CMi/G — CM — — — CO
CLCDQCcDCLQtccGDCLCDa i a a £L a a a a a a. a ai ai
OOOOCOOOGOOCCCCOCCCCCCCJC
irsiTsiftsirsirsiflsirsifisir. s/s itqits
xoo'ss — — aJCMcoco^^i/iiT'C'Ct^t'-a x im> 5
awannrnrrnnrnrrnrrrrrrn^
it it it it in iTi i/iifini/iir>iriri/iirir>inu'iriri/iir. ir, it
r'DiniPCM — ®a>r^p'^'LCM — s x ir a> - s n
■T 1 — — cm — — — cowcm — cv — — — ro <r ^ <j <7
D
CLCDODcrcLOCtracicraacLaiCLCLcr c? x a oc cc cc
CQOCCCCOOCCOOCCC UJ C O C O O
X
co
CL
K
* c
iT(si/isirsir®irsir®ir(si/'isiri®inKifl®i/i
it — — CMCMcocn^r^irir'C'cr'C-xxa'O'®® — —
i/iifli/nriniri/nninriririririr. iri/uftiriftinirm
cno'ocL« — ^acMcuaMtCMO'Qn
s — — ®®®cm»o — — — ®«kcmpo® —
l/ 1 'Gr~X< 7 '<ICQOCUJU.® — CMCO^lT'C
CCCCCLtEQDCCCDCDOrCLCCaOOOOOC
IL L‘ 111 UJ U 1 b . 1 U) UJ It U! It 1 U 1 Ul kl u; U . 1 U U)
cccooccccccocooccc
O'CCL^nO'CLCMCOODC^O'C — O'
— ® ® s a: ro — — — s s s cu n 5 - —
Mio'caiucuu.s - cm co <x 1/1 >© t"
OCUCOCJCOOOCCCOCCC
u; u 1 u. uj u: uj u u uj k 1 u: u u u u u u
occooococccocccco
eff «u»ns<roa:<iir9>oua'c
S 58 -r---S 58 WrSS -*5
OC O' CfflCCU'US-CMr
C C C O C C C C U' U. UJ U U UJ UJ UJ u
u; u u u; u u u u u u u u u; ui u. u u
ocococccococcoccc
cc<t«^0'aii.'<roa<i'c o — o'ooac
® S CM r - ® — ® ® « G. 1 CM CO CM CM &
0'<raiccu u®-wn^^^ifl'CM
UU.U.kUU.UU.kli.UU.U.U.U.kU.U.
uui uj kk k Uk k k k uj uj k uj uj uj u.
coocccccococoooooc
o
UJ
2
X
r
II
0
r
11
in
s
■q
II
a.
z
"5
<r
11
o
2
c
o
CO o
-J u.
♦ ♦
tf Kutfl uiowHuoznn
<r a c i o c i oc/>i-c-ozx _ 5 .j
oc-Jcr a: u »- a:
c<r_ic-Jsau»-a:i
■ -r t t * ♦
o: irt-a.uia.Di/ia.ca.xhi
Qtc/i»-a.oxa-Z>c/)a.ca.xi-x
cv
1 r
11
2
_J
c
CO
to
II
t-
D
C
Q. I
Q. I
*r
if)
II
UJ
1/1
i/I
II
o
2
2
iiaaiiraaaiiaiaia:icita:(Laiiriiairaaaaaa[iaa.aiLa'iiajiia i ita(iaiLiia
ooccccccccoocccoocccocccccccccccccoooococcoc
a a a a a a a cc a. ajQDajOLcca. ccacccra
ccc cccoaoooooocccooc
c
2
2
<X
z
u
a
c~
c
2
<r
s
h r
c
1 - a
0 : a
u
> z
2 —
C </)
e x x
a o
ir h- c
U C/1 _J
j ? or
a —
<x a.
c h u. c
o C'
3 - {/>
C OJ U! Z 5
a: _j x <2
c -J ~ uj u
C 3 C
u. c 2
«J — X
a
c
2
'c
1/1
OJ
o
®irsifsif5irsinsi/isir®ms
cii cm r r sj <3inr'£'iM'iX(j'a'5
XXXXXaXXXKXXXXXXO'
1/lKlTS / SlfClTEifSifSiTSl/IS
<s — — cv. o r'ro •qiriP'L'X r-r'-oecco'
O'O'O'O'^O'O'O'O-O'O'O'O'O'O'O'O'O'
IflSlfSUISi/'SlT, SiTEifSlTSin
(>88 — — c\.cnrr <j <j if~ ir < vc r~
O'SSSGSSSCSSSG®®®®
viriniririfirifiriri/'ir.irifiririr
smsinsinsinsi/isirsirs^sir
aoxoo8®--CMC\inr < j <j it tr »c »c
®®®®——————————————
i/ii/ii/iini/ii/ii/iiri/ii/ii/iirinc/iiririr. vr
— cvee — rcrco^nc
K — SSS®SS — — GS
r'<JiT'ir'KO'«iCLccu
r~f^r^r^p»r~r-r-r-c^r^r-
UUUUU'UUJUU'U-UJU.
CCCCCCOCCQCC
c s <r s sco — cross
<J— U <J®S<TXU.<JS
US-UCO^lT'tl'Xff'
r-xxxxxxxxxx
u u. u u u u u u u u u
COOCOOCCCCC
CMiT-qCMSSCMCO^Sr. X
— S — U.SSC — — — see
<acDuiu®-ar^ir
xxaxxxo'O'O'O'O'O'
UUUUJUU.U.'UUUU u
ccccoccccccc
sir. ro®u.®x<jxroG
it — r-irs — — — x — —
'cr^xa><rxc'cu u. s
0'0'0'00'0'0'0'0'0'<r
U'UUUJ UUJUUUUIU
CQCCCCCCCCC
xo'U-SU.ir^i/iO's ^O's
CCSCMSSCO — ssssss
— ur^iT'Cf‘X 9 'flttcc
U U : U Ul U UJ U UJ U! Ul UJ u u
cccoc eccoaccc
UJ u. s IT u <J X
s S — — S S CO
UJU.® — G.CO'Q*! 5T ^ ^
CCCLCLCLCLOJCLajaDCC
uj uj uj u u u k k u uj uj
ccccceocaoc
Page 14
300
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
Si
3
IT
O'
3
3
® iT>
m r-
r~ S
3 l/ -
S
O'
<3
<T
3
a
3
s
a
cc
<3
IT
CS
X
<1
(T
r-
3
IT K C if
® 3 3 —
r- — 'c r*
3 X 3 X
S) ®
00 O'
O' r
•3" cv
<S> ®
cm r-
O' m
•3 cv
O'
3
3
X
3
3
\T.
O'
IT
3
e
IT
s
3
s
O'
3
S
3
3
3
in
3
n
3
S
in
cn
3
®
x
3
3
in
cn
co
3
in s
3 CM
3 CO
3 3
S
IT
3
in
®
to
3
m
®
IT
IT
CO
s
in
®
O'
O'
3
m
x
IT
3
®
P-
m
co
S ®
m 3
f" <s
3 S
S S
0 3
p- p-
3 3
s in
IT 3
3 p-
3 3
tn ®
3 CO
3 r*
3 3
s in
r —
3 p>
3 3
in ®
— 3
3 3
3 3
s m m
s s CM
3 _ 3
3 in 3
6. in mm
e — —3.
f" x r 3
3 — 3 CM
m in g
3 ® m
3 O' O'
3 3- —
r- x
m cm
— 3
in ® m
sin m
CO O' 3
CM 3 3
® ® ® in
- vO O' O'
s in cm r-
in 3 3 co
in ®
CO CV)
m 3
3 CO
ms s ®
3 x a —
CO 3 ® 3.
n 3 in 3
m
x
3
e
3
3
m ® m
3/ CV
m x in
3 3 —
m m m ® ®
m O' 3 r- 3
S x 3 cv —
CM m — 3 in
m ®
p- r>
CM CO
CM CM
in m ® ® m
X O' CM 3 x
® CM O' 3 O'
m CM 3 3 CM
m m in m ®
3 O' 3 r- in
m O' m cm r-
— 3 3 3 co
® ® ®
CM O' 3
m CM 3
3 - CM
m m ® m
in in O' O'
3 s x in
3 m 3 3
m m m m ® ® m
s cv a m cm ® m
3 cm r co m r cm
3-— CV 3 —
® in m m
3 co x x
x O' cv: cv
— — CO 3
m m ® ® ®. ® m
m — m ® O' cm cm
X 3 O' ®3" p- r-
3 — CM CM CO ro cv
in ® m m m ® ®
® — m O' c m3.
X 3 ® ® ® — X
CM — CM cvi m CO CO
m ® m ® m
3. fO 3. ® CO
CO CV CV — CO
r- — 3 m cv
® ® ® m ® ®
p- co ® c co 3
3 x 3 m in O'
--CM — — 3
s s m m s m m
O' CM CO ® r. 3)
— X 3 X 3 r O'
X 3 3 X 3 — 3
m ® ® m ® ®
in P* 35 3 3 ®
X3CMP-P-P-
CM 3 3 CM CO CO
in ® m s in m s
3 — m cm x c- —
P“ X 3 3 CO CM CO
CO CO CM — 3 — —
m ® m mm®
s m co 3: p* co
3 cm 3 r~ x 3
CO — 3 3 3 3
e r- a> ® cv
O' CV co 3 £
cl a cc c s
a c c c ®
CM — — 3 3 CO
p- C u o 3 ®
c x a cl c s
c o c c c ts
p c. m o: cv o ^ o> u 3 u p* c o x 3
O' u. s a. c cv u <r u u u c^ 3 3 x ®
accocoeaaa cocoa®
00000 0.0 0 0000000 ®
cr x x — 3 r* u. m in
— — 3 3 3 3 3m®
c o c c c a dc x ®
CCCCCCOC®
<xr~®®®®(^®
® UJ ® — 3COO
u.ssscsa®
oc®®o®o®
®®® — 0)3X3
3CM3CMOXCU.
SSSCCkCU
®®®OCOCC
3U.mXU.C0X3O'
<tX®®0C — O'®®
D«im®oxccs
COO®OOCCS
<T ®
® CM
s ®
s s
mi-— x x
OC Z X 2- c CL CV
CQ.CC <3 X-ll-
o _> in <r a _j cn m m >- c
<T 33 axa-atraxc
u c p- o x — a <r
C 2 C — CM 2 P- -J QC H 2 X
i CM_J
zxxxxxxxxxzc a. on a. c.
C C c (J O <J C C C C C' c c o c c
- -J -)
XC-1ZXX X _)
-imcnmm _) ox CMtn«j
U.tN»-HH|/)iflu 2 C OOOC *- 1
ccccccocxxxxxxxx
XXX h JZ
x m x ® co co h x >- x ff >-
XX CMHXXXX _) a J 2 V)
zxxtnmcxxxi-33xxxxx
xxxxxcsocccxxxxixx
r> cm
"5 -1
X _J
O I
X h-
X X
X X _] X UJ
m — i- p- o _j~i- x h in — p- o
Z)oin ul z <rc«n c “ zzm z
xcocxx-ozoo^ocxx-oc cja.mxxD- 5 '
X
cj •— o- a. i in —* p- x x o -r- p- x m •- p- x
2 x in c H Z> z in o o z x in c — zxm a —
>ZcnXXX“DXcX<rXXX“3Xo3XX x x z> c cj x c xxmzx
■ Pr'WW'Cmo'-
rm33CM3333
nrcoco'Cmp - CMcop*33)mo'
m33CM33m3m3mCM3
— ®fooco'3mp- — scoP'S'Cmo' — mmx — 3m —
333in33CM3333CM3inc03 333m33P-33m
>- 3 a m u
xxxxffxxaxoxxaa'xxmxxxxxxcixxmxa a a. a aa xxxxmxxxx xxxaxxxa o a a a a
000000000000000000000000000000000000000000000000000000 0 0
Z 3 Z
in in 0 c
X C O X c
_J x
x a
* * c
®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m®m® m®m®ms.m® m ®me m®msm. sm
xxcocn 33 mm 33 P'p*ttK^O'®s — — xcjcor) 33 mm 3 > 3 P‘P-ttao' 0 '®® — — CMcvJcocn 33 mm 33 P‘C^Ka<T' 0 'es — — xx
mmmmmmmmmmmmmmmm 333 33333333333333333 p-r^f^p-r~p-i^p-r'p-pp-(^r^i^p-p-r-ppaccixcra:ci
mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
0 3 2 0
m a > z
* c cn x
® m ® m ®
cn r 3 3 m
x x oc x oc
m m m m ir
CU^^CC'CWO-ff'iTXSPUJCO'IJ'O ff <?'XXO^- 0 'XX®CXCXl> 3 XO'
^ xxnxcnxm—xxcnxc^xcr — xxcnxnxm — xxxx—xn
is m u u u «• w uj «.
m — xxxxcnxx
0'Cmx®cxcxo3X0'Ujxc — cpr-a ®xu cra'3aa'®x
(M«fti(fi_«.AAiAi_fti» pl fti^(rXrxn-XXrcvrR.rftia
s ®
x x
s s
X X
cpccocxx® — xn3m3t^xo'<ixooxx® — xc r )3m3r~xo'<rxooxx® — xn 3m3c^xo'ca ooxxs—xcn3 3 3 <r<
xxxxxxx®®®®®®®®®®®®®®®® — — — — — — — — — — — — —^jxixxxxxxxxxxx xxx cn cncr co mm cn me
XXXXXXX'XXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXX XXXXU XXX XL* XXXXXXXX X XU
oocccocccoocooococoooccccoooooocccoooooocoocccccocccoccccccccc cc
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
301
U. «*5 U a 6' c l c
<iiL^ircviC£(j<iu
— oousscc-
a u cd a r m. - q
u U‘ c c s r c u u*
ucvqocvccuaq
ouuo'Sr'-—c —
o o cv c ri <\ o r- c
p“Xcoesco-o
<ir?<ia'&-iica
<x-c- e s c c p*
cl <r cl s u p- a c
Ui — — r- r r o u c
O' o u r u c c u —
ccii(\ rcccc
i-uii'ru-ac
c ® u r- s q c (" c
qcv<rUk/-ccv<jq
CO — h. C C 6 a «
CvrruiTr-irc
c-r c s o- u c
accii-cv-cir
COjCCUSCCC
p- o u o- c s s — c
O'CU'P-qcvcqc
ci/’rcvsiu.^fl q
ceccvqrscx
— c r c s r c a c
cc — ccsc-'cc
— uo'O-p-cvO'O'c
u U-OU-CSt'UC
s s s s s s s ® s
LLS-ar^iT'f
a a e o o o c c c
ccccccccc
c i' 1 ii. i' 4 n n s
- LltO/'O®
r r'c , mcv<ru'®ui
— e®cc<j<-'nr>
rs-ocirsfT'Cu.
S U ® C U q ® o m
cv q — c — ui o. x n
su’ccvuusp-x
s<r<r<rr~ir. soo
q — ® C m U m O C
c. " — r- — ui cv u.
esqueumuu
CCVXC'CCCCVl —
c s x c u coo —
S SSCV U ® X ® P*
c q c i^o — cmos
<3 q u q u cm r~ u <r
C o r> O Q O C u t*“
USUSU'CJTQC
— UquSSmQC
qu—uuuux®
u r-xur-urev —
cccirct^nncv
-ccucmsco
rt^xs—'Ccvit-s
-xuucvsemu
r^-'Cc'Cruu
s c s u o u it r u
cv Lifcif«ru.rc
s — o — up'nsc
S'cr~aeoccvx
q u ® — q c o ® cv
®s®s®®®ss
r^xo'cccocu u
o o o o o o o o o
cccccccc
Cf^<r it 1 c s n n i/i
CP* — II c it u (Oil.
xoircaujooo
CV (J U C U U ® C P*
nnnqruuiuJD
os — qevt^nue
ro.rc'C'Lii.-L.
ssasoir. UJ« — 00
cvjc — r^cuncc
® c c a css co
sa — c t- cd a q o
cvcvup-mr^si^r-
u cv. n u <rwocnr:
r , c'®mu®qc®
r <r cvj c c\ s ui o cv
s — scsnncvjs
cv ® <x c u u 1 o u x
® <r — 'Cuncnq
<ru c<rn cuo'U
— UCC* 0 0 X 00
niocr'uoono*
— U.I'SiT'flOSO
n — C'ccnncvjr-
SU-OU P* O ® ® m
CVOP~^C^C®q
scsscnccvx
— M^SMiJ'CplS
^cu^qcxou
wof^socuen
cac—eqxqu
ap'ccuxp‘r*m
®sss®®®«®
s — cvi r q iT'cr-oc
ccc c c o c c c
cccccoccc
qnr — — <rnno
e*ec — xmqt^®
<tuocuujcvcvx
ccnoqqqs®
qqcxuixsm®
nee c o o m cv — —
ui — cc n'Coo no
u — cosqq f -<s
®c<rr~ — x®or>
tr c os — q cv ® q
qcvxqqr*®q —
cast 1 — qmss
ucvu'ur~qm — cv
somsmqqq—
q®qu«i®®qu
uiqr^sxcvmsq
— U UU ® O' U^T —
uu u. s e c q ® s
cuocujr-® — cv
CP-ccnmmq —
XCCVUU«® — ®
O'Coovneccvqf^
cqcvcvrsnc —
op*eex®qq®
unssuunouj
soo&onnqq®
Ut^UUiqUUX —
sshhhiir qq>c
u.<. couirsmcv
socccxcvq®
uccvccq-<rqcv
sccouxmq®
sssssssss
O'CXOOUJU® —
OCCCOCOU’U
qccogccco
0'ncvo'CVQ®n
®ncv® — q® —
x — mujn<®x
m<i—cv®®®x
oqo — cvncvq
cv®®® — ®u —
evom — cvqqx
— cv n ® — — — —
uon — nnms)
®cv — ® ® — ® —
O'xa>qoocvu
x q ® ® ® ® — s
cvnnqao®®
— — CVJ® — S®lT
no — — o»n®n
®cv®®®®qp*
qooo'q® — nin
®q®cvn®ui —
a-oqxnco®
s s cv — ® ® co in
<■ - -non — x
n®®®®®qcc
oqwqcvcvnn
k in q ft n - ®®
'Cnnxu — ®®
— — ® — ®®® —
u — oou , 0 'cv®q
®® — ®s — q —
cq — O' cvj o 4 r
c qawrsiii-
qoqo'W — ®cv
— ® — s—® — o
KSSSSSS®
ftnqiT'CMcO'
Ul h h h U U U! UI
occecoco
uc^qi^O'qq't
® — — — — nn — n
ucvcv®uja>a>0'a>
® — — — ® cv cv cv cv
smmccccoo'Un
® — — — — cvncvn
O' O' O' O' O' c ccc
srnnrftftftft
q — non-uiuuu
® cv cv — cv cv cv cv cv
®q<««»nn-ou
® s ® s s — — — —
O'GCdjODCXSS®®®
®®®®snnnncv
moooca a cc a s
ssssscvcvcvcvcv
qO'O'O'O'Xincvn-s
— — — — — cvnnncv
innn — UO'O'O'O'S
n — — — ® cv cv cv cv cv
ucooc — — — — s
®®®®®nnnncv
®» 0 ' 0 ' 0 'CCOC®
®nnnncv^icvcvcv
uiqwqin'CU' uiuhi
cv®cvwcvcvcvcvcvcv
O' Ui <X <1 <1 <1 * cc u. ®
® S S ® ® ®-— cv
CLiraa.curca'O'O.
oc — s®s®wnnn
ssooooaa cccc
— — sssscvcvcvcv
®® 5 ®®SS ®®5
<rccoou)U® — cvn
Ui U 1 U Ui UJ u u u u u
cccoocccco
cv
V
n
I*
u c
h- _]
U T
it L.’
Ol u
• r r
U w
a>
.2f
IZ
c C
2 :r
— c
y. c
Z X
c o.
V X.
: u
c a
c ^
: u
\r
> t/
a c
c r
-i c
: u i- <r yi
a x <n x i
'l x
i. x
~3
<J IA>
X CC
sssssres
— o nqir<r»a
eeesess s
sssssc ss
css
O' s —
c-
css
O' c c CL
c ccc
s
c
O'
c
X
i
w
tn
<r
o ccc
esse nnrsr'CO'
ccccccccccc
O'O'O'O'O'O'O'O O'O'O'
CCCCCCCCCCC
r> in
cv —
cv* a
n q
c.
q
£'
U"
m
cv
O'
q
®
O'
q
in
O'
oc
q
s
x
x
q
m
n
m
q
®
cv
m
q
m
s
m
q
® ® ®
n in 'O
— x ®
n q in
ip in in it
q x n —
* ® x P“
n n q q
s ® in in
r f ft if
< O' q 'C
n cv q q
m
®
s
in
®
r-
O'
q
® ®
q x
x s
q in
it ® m
r n cv
q ® ®
q in m
s in in
cv r- oi
q o r-
q q q
in ® m s m
q q q n r-
q in O' — q
— q q m- q
s s in m ®
q r q r- q
q in x ® q
— q q in q
® s s r ® m
r s x q ® r-
q v n if c i r
— q cv q m q
s m ® inm
O' q i*- O' cv
q n q q o>
q cv q n cv
® ® s ® s
® q m q O'
q q q m O'
q q — q q
s m m s
p* s — q
m q m r*
q q — q
® s s
cv — r-
r- q —
cv n r
m m mm s ® ir
O' m r — x cv s
f~ n o — r- q r
— q q cv — — q
8 m m £ m
cv s cv n
— m q q q
cv q q q q
in m ms ® mm
I'mso'ftmto
q x r» ri n q x
q — n q r r ft
® m ® m m m
p* cv — n cv x
r? n m cv- m m
q q --q q
m m m m s m ®
s-mminr-
® O' q m n m x
m q cv q q cv r
m m. m m ® ® m
s x q p- — — s
q x n q r* r-
—-q n — cvi
5 if if SS 5
x ® s q q q
m—mr^xr
r r r - ft <j
ir m m m m s
cv O' q — x o-
a q t" ® m cv
q — — cv — q
m m m ® m
f- O' O' — r
O' m cv q m
— q q q q
CCroO-DiiJif
CCWCCChifl
rftcu r-0'<rcv
C'Cif ftOSO
scoucvm — m
— c «** u c o o c
r'ccammof'
c c e c — s a O'
rqc^r-cvuc
c a c r o c q c
<roucvr-a:o —
r e a u s c c o
r* m- o u cv r- m x
c o e f* ® O' c e
emu u u o m. cv.
c-on-ucvocn*
a h r u it — u c
— c cvi t- r. c C c
r'O'Cisatro'U
cr'O — ccr'D
s — u. q O' cv — q
c s a — r- s r
uac—cvccr -
— c c u u c c ®
r ft h a g — cv a.
cxr-ccvcxc
n q m <i <r x u
U S >i) U O 111 h
s' c « u ® m q
s a o r* u ui r*
— 'f. O' >£ <r CL c-
o u U U U D CV
<r e* c x- u — u
COUOf'UMi.
O' <r q cv q
usocuicr-
c •* c r- a c_'m
e s O' u c c cv
I'CflCif—ft
q c p* o a < f*
iT'iiTO'GCC'-
cj u O' o e c cv
a c a a <r m n
c o p* U' c c r*
cv o c — r u a
xsccuou
c q q c c O' a
c s u c o r c
carcs-r
s c O u s u
uo'<rcsa<r
u <r c c cv c c
® 0 'Cvcjf-qxou'
quiosmr^cv®®
sacsccc®®
®co®ccc®®
qo'®s®sx®ui-
nncvqqau<r®x
uussss cs®e
cossssc®®o
q cv if s s if. u 'C
®r>xu — qu®
uxxxsoq®
ccccscc®
C u ® C X O' (T
r* u u c — u u
a c <r c s c. q
O C C Q S C C
— q r - u. O' q m q x
CU— S 1 ^-— —
CCS C u ® s s s
cc® cess®®
q x >
XX CV H C
z> O CDH
sxxjzctniz
_J-l_lJ_J_l-JiZ
-1 X
zucex_Jh-x
uz?qqqqqq
CCCCCCCC
PO X z u o
x <r _i m x x z
U I- H D X In o 3
c xxzi<icxxmtn
c cccxxxxxx
U X Z 3 .
c f- x «n
CL (1 t— X
u u u x a
x a a x x
> a
?Xfth I-
c z x r i
c — x c m h->h-
m in in m m m m f—
> x
> X
m r u cv
u — u s
x cv a. c
sees
q m p- u
— — r* r:
C r- <j c
C S O
x oi O' a
cccc
c ® X X
O' X C f"
O' s c
0" c c
u
c q a
s c
<r
u r c
<r c O'
o
X s ® ® ®
2- u s - x
r <r cr cr cc
c c c c e
s ® s ® s ®
r- q m 'i r* oc
x x x a x x
c c c c c c
q u ui o a
U U U X c
C u <T C O'
C hcch
S — S O' C
S X U C C
S S S S S
O' <r ere c
a x c or a
c c c c c
Page 16
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
302
X 2
<1
c ?
c
C 2 1/
i CV V
L
t- 1 . u
• - C
7* i C
S' tf c
U 0£
£
C U.
2 C
£ -K
£ C
c c
c c
x l
U
X c
2 b
c z
o a
a c
2
b <J
N £
— k
-) C
c a
h- £
-~ c
2 X
— u.
2
C ~
»- c
—■ a. in
£ C b.
C
X u. u.
u. — —
i. H-
C ~
X W
2 — C
i u
t*
C b
C - i
2
H C
__ x X X l
0 2 2 2 :
— — C\
X »- K
I- X X
HHCCV){/)C/)(TU.UXI-
WWIIIIHIIDCQOXIl
- (— * H * t- • H * »-• CtC
C 2
H C
or
m u.
u
2 <r
— u
l- i r
Z IS
c u
a or
a. c
r o
in <r
«> ?L r 11
roc- u-zcrai c
i
f—
e. x u; C- c o x
ji—cx— £ x x _j r c
XI - C I
—J a. •- a X •- i A i J x q •— — — — •— •— >- COCO <T -*
rcxczxNcooxoca.isja.Njr£a 2 - f c a. a. c c c <r * c
jxjjH(jTi/!oxi/!X_'i;2ctt:v:L‘ji/'‘:<:c‘)COCc " -
a.
s c e 5 f
a o g — cv
I' r- i CC i
s s s s 6
SCGS&GSS&SS&GSSGSG&SSSGS&GGGSS
<jiT'cr-xo'® — cvio'cin'Ci'-xo'S—&io'Cir'CP“XO'S> — evo:
xaxaaxO'O'OO'O'O'O'O'O'O'GSSGSSSKSC — — — — .
sgsssscs.kssssssc: — —---—-—
css ggsggssg sc
ir'Cr-aos—cvio'cif'xo
-«-cv cv. c\j cv cv cv cv c\
ggcssssss
o-s — a r ^ it < p*
Cirrrrrrrr
<T
C
<r s c
os c
<1
c
c c <r a
c c c o
<J O' — O'
IT C <3 C
03 O' n O'
IT c m C
'£0X0'
<3 c in o
s c g g a <r a — a c g a
o s cv. rose—evs—cv.
o
0
c it o r r o- O'
e c --c u
rrct'CKO'^c^
irc*o*G«*c*
u x u s
C m lx K
<r a: — <i r uj <r
CV U CV — — lx C
aacva<iixccux'£<ju<r*
— liCVU — U-C**C_'CU u. ix c
C'tucvo'O'O'O^uro
ucixbcvcvcvcv a * — e
■<3 O <1 <
ir in in ir
<1 <3 <1 C
CCCC
<i a cess
if 1/ if if >f *c
c <3 <r c c «
c c c c c o
<i <t <r <i <r <
c c c c c c
r- o clou¬
's < vc 'C *
<i <r <r c <r <x
c c c c c c
03 if r* O c C <3
i*“ r- r- r- t- r~
<s <r c <r <i «i <j
c c c c c c c
<iccu—cvninxao'«3
ot'-r>r-xxxxccKxx
«<r<r<r<i<r<r<r<x<i <r<i
ccocccccoccc
Cixix — cv'Oirr^cc
XXX O'OO'OO'O'O'
<3<i<x<i<i<r<r<rc<i
CCCCCCCCCC
ix — <j'cxaecu u.G—o
0'c<i<r<i«j<3c<rcacia
<rc<x<r<i<3<r<r<r<c<:<r
CCCCCC.CCC-CCC
If If If If If
x a a. a a
< <i c <1 c
C O C c c
<- _J 2 • ;
c c - c :
x —
= X X I .
u c <r u ■>
O Ijl V — — ■
- 1 f- 2 S S
r x r — o <- 1
ocx j r
2 </»
nee
b c J
£ 2
x - : a c ? r <r
lx>
U
c
£ C
X X
<T
C lx
>• c
I u C J I If
z cl - u. e m
s c a c u u
u r — <j in u i
ii-TX-a *- c 2 <r c
ot-ac Z2XXC
aaxacxc xx
> c a h > c
c ucc c_r c — -x
c*-a»-bc<r+ -*
= C k X
a c x
C' r -- a
- C b
c t- 2 x r a
0 . b
r- C
X
0 12”
- > - is, b - _ C
Xts<CX2l_'X<32
c ■: I i: -3 <IJ c “
X — J X — _
C‘ 5 <3 2 x <1
C 2 C' “ J C
1 X — .
x a rv
2 k 2
— C
C X > <x
c 2 C c C
C b. h- G* 2— — k
j J c b a r- .jt ix u c
if u. i i: ix 1 x ? r i- b _ i b ->
COOC>^-CU C US c b
hi-Hi-i*if'ni**ca*# *2
SGSC. SSSSCCC 5 GGGGSS 3
cv r ■q m 'i a ocgsgs — Ci o <i / >i
-—-- CV 5 GGGCVO cv CV cv O
GC GS^GG^CTGGGGGd SSSS
GSSGCir. T GSG. GGC5 GGGG
CCO'G — OG'Cif'Cr-XO'G — 0G<3
cvcvGrrroroGor'^’qc'g'q
SGSGGGT GGGGG GGGGS
SG- GSGSGGSG. SSSCGGC
XO'G — 0jO<3iT'£O'X0'S — O O n'
VlClflflflflflflflflflf'f'l'f't-f
G. E SCSSGGKSG- SCS SG G i
C G C G G S S
ais-cvr-Jif
'Co-o-f^r^o-i**
G G T G G GG
CL (J CL X G ^ G
c c c c c c c
c O' O' c o O'
c c c c c c
<T < COO
c c c c c
O' coo
c c c c
oo cccc c c
oc cccc c c
lx x cv u o c
<3 — O' x — — e
if' ii a
bob
b X b C 03 lx b
abb G O* (" —
— G
c_ c
a c
CV if
a
00:00 o o o.
C C C C_ C_ c_ <0
C < CL — CC r-uc^UCV
CSC CV C_ C b C b C.
c a a < c r
c c cv cv c c o.
c cv
c c
<CO — cv C— C 0 r~CCCV< 30 C.CV
see cvcvcv — — — aeae — — a c
e b. cv m a x a
c c b e u u b
O' O' O 0 0-00
c c c c c c c
a b---
bbblxblxbb.
O O O' O' O' o oo
cccccccc
---^ r- o
U U b b b b b.
O O O (X- O O' 0
c C O C C C c
c c b. cv u- ȣ x a
bb.bGG SSS
OOOCCCCO
CCCCCCCC
eb.- ■vjr'-ca
GG---
C<T<3C<1<X<IC
ccccccc c
eu — cv if a a a a
— — cv cv cv o tx a cv
ccccccccc
ccccccccc
c s o o 'C o e
cv r r o o o o
ccccccc
ccccccc
b-G — CViT^Oca
occccccc^:
ccccccccc
ccccccccc
C b X G — CV O
'j'iNirififir
c c c c c c c
ccccccc
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 17
303
Lt iVt IWL Sfc)cJ/. 7 Sl i«v t\u» m>‘j I U*. VdvU
l Obtf'S I ddllU JlilWV i llllli.llj U duel wo7 l lU bbVU
AUOJd u*j< du biijduuv- M l.ri MivitJa I Ivj ob? 1 vij wZ. uj ^avu
rccuao'^cccru'Cvr
O S C — u c -- C C 5 u c x
xrccvcaccer— dCO'O
C O C C (_' lx C C C IT CV - C CV C
a c i» ii ii c - ar-^aaacra
• ! 3CflCf^irc.''fi/'CCU l* < $J lx.’
r~ O' — u'tu. — cvro'ccca>r
C-CVU.Gr — C — CCCU.CV.U
i r a- r~ a <flcr.
:cc<iMcii-ccceM
c N ' j. i— z r: r
& s L ■ U *? l/> ^ '/I / c 6
C 2 X ■* Li CU.CC ti S
vl
S
U. J J
•* u. x c- «
r ? h c a
1 X z a. i- a-
* r # c c w 7 s
e
<5
rcrcc'-cr-yssr s c 5 ®
— 0 '-«<r J*‘0cc-y— or — >£ — r
cv s <g
----— — c — 5: c
r sryisyryrr?
n <;r<rrM.ai — r r-
ICCEE 5 C:t;-Sf'
gorges sires
— <31^ — *. a cv x cv
■qC'cr'oa ® ^ r
— csss—-cs
SEES s s s s s s s
9 "£a^'iai'sa<i&
cv a it cv a ^ ci. s » ff 1 a
cgsssss — see
— CO <J a o tx r'r'r-ccvucc
ecu c a c 1 — - if c o u. ; b
rucc r '0'U<i<ja&/ECi oa —
c — cr»eucv~c*succve
<x r u <r — cvi <x <3 — O' o a a cv c
ccf^cucccucc — cv u c
iitt'tcci^c<ir<ii<r< 5 fl
lx. C <S S CCCU“C'CUCU — r-
c - 1 cv o> e o-cvicvcvc — cc—sue
o oc q u c u: Ci c c * it x r u c
orirr-cvoaesaa < * c it
c c u <*“ u e c c <1 ir c c c w
u a c o c <r — dOO'O-set'Oe
c c c c c c c c c c c cv c c c
r (^cu.<xs — ccr^ruuscO'
CC'CU.CCCVCV * C C U CV C »
uuu—uuriu
u - c a 'f 1^ — o r
sc<T<rs<i<r<i
SCCCSCCC
<J c 1 o-
a 0 u e
L ii _ fir 2
2 CCUUUUUGG CVS U U a c c c
acraaccracrcccu a. rrrc—iXic
<!<r<i<r<'<i<r<Tc<'c<r crcrai-iici?
C.OZCCC.CCC.CCC OCCCCUUU
— u so — <ro roiru<iaii'£sE»'Ciiru.c'i | r
a u 'CiiLiTirrca ur-uuECU.cu u c c c c
<Oa<30'<I<TG.<CO'GO'0'<S4GO'0'0'0'00-0'
cccccccccccccccccccccccc
0 . 0 . 0 . SL T' > X Ci U
—' —J -Jc— cv>x20l?o.i- ore _i
ex x 3 h 1- it o c. ^ c ? r i-<ii/!ifl:ita. <n-
■? c C uuxxff«j(/ue-cxxh-occccxt^
UCCX?2 , 2c 10.ttiri/!(/;l/lt/;l/l|-hl-l-f-hl-
a. c c u c a. — c
<J
c — c — a> — r —
u c r c — CV u
s
erasotco-r
O' c — c u c c c
XSSSSCSS
xcuus — cv. r
_0'0'O'C<JCC
cccccccc
cc^i'iru.ar'
C - IT <J - It CV c
rer^<raccr
a * ir c — c x —
rro O' 5 c — u.
-u c s c — *
ggessggs
^ ir \c t^coaco
o<j<r<i<ic<r<j
cccccccc
Page 18
304
Or. Dobb's Journal of Computer Calisthenics 8c Orthodontia, Box E, Menlo Park, CA 94025
Number 27
BY MIKE GABRIELSON
Box 2692
Stanford, Calif. 94305
Memory Organization
The 8086 can address one million bytes of memory, using
a set of “segment” registers. Every byte has an address. Loca¬
tions FFFFO! 6 through FFFFF 16 are reserved for the initial
program load routine (the CPU jumps to location FFFF0 j 6
on reset). Locations 0 through 3 FFi 6 are reserved for inter¬
rupt pointers (described later). Addresses are 16 bits and
stored byte-reversed in the 8080 fashion, but a 20 bit address
can be constructed before a memory access by offsetting a
16-bit effective address four bits to the right of a segment
address contained in one of four segment registers, filling in
the four low order bits of the segment address with zeros
and adding the two. The segment registers define the
base address of four segments (a “code” or instruction
segment, a stack segment, a data segment, and an extra data
segment) of 64K bytes each, with each segment falling on
16-bit boundaries. The segment registers are named:
CS code
SS stack
DS data
ES extra data
and each is 16 bits in length. As described above, they are
extended with four low order zero bits to form a 20 bit seg¬
ment base address. The entire megabyte of memory can be
divided into these four segments and is dynamically allocat-
able by changing the contents of the segment registers. In
addition, an entire memory block up to 64 bytes, can be
moved from one group of memory locations into a complete¬
ly different group. Word (16 bit) operands can reside at even
or odd addresses. Referencing word data (but not instruction
fetches) at odd addresses does require an extra memory
cycle, so it is worth it to locate word data (especially the
stack) on even address boundaries.
In addition to the segment registers, the 8086 includes all the
8080 registers (but with different names), plus a few new
additions. The four 16-bit general registers have high and
low order bytes which are independently addressable. Thus,
the 16-bit accumulator, AX, contains the bytes AH and AL.
The other 16-bit registers include four pointer and index
registers as well as the instruction pointer (program counter)
and flag register. A breakdown and comparison to 8080
register structure looks like this:
8086 8080
Name Name Meanin g
General Registers
AX — 16 bit accumulator
AH — high order byte of AX
AL A low order byte of AX
BX HL 16 bit base register
BH H 8 bit register, high order byte of BX
BL L 8 bit register, low order byte of BX
CX BC 16 bit count register
CH B 8 bit register, high order byte of CX
CL C 8 bit register, low order byte of CX
DX DE 16 bit data register
DH D 8 bit register, high order byte of DX
DL E 8 bit register, low order byte of DX
Pointers and Index Registers
SP SP 16 bit stack pointer
BP — 16 bit base pointer
SI — 16 bit source index register
DI — 16 bit destination index register
Instruction Pointer and Flags
IP PC 16 bit instruction pointer (program counter)
flags — 16 bit status register
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 19
305
Intel has been slowly leaking information on its new 16
bit microprocessor, the 8086. Except for the concluding
paragraph, the following is intended to be an objective report
describing the various features of this new device. I have pur¬
posely skipped most of the hardware details (such as pinouts
and interfacing), since that is not my area of expertise. Of
course, all specifications are subject to change by Intel, and
no endorsement of this article by them is implied. Other Registers
The 8086 status register contains all the 8080 flags plus four
new flag bits:
DF direction flag (for string operations)
IF interrupt enable flag
OF overflow flag
TF trap (single step) flag
When TF is set, an interrupt is generated after the execution
of the next instruction. This allows efficient implementation
of software to allow single stepping, such as in a debugger.
Addressing Modes
8086 instructions can be from one to five bytes long, with a
large number of addressing modes, but the basic two-byte,
two-operand instruction allows byte or word operations from
register to register, register to memory, or memory to register,
and is formatted as follows:
Field
Name
# Bits
Effect
opc
6
opcode, selects instruction
d
1
defines direction: operand 1 “to” or “from”
operand 2
w
1
selects operand width: word or byte
mod
2
sets addressing mode (whether r/m is a reg)
reg
3
selects an 8 or 16 bit register with w
r/m
3
same as reg for one mode, else selects which
registers compute the effective operand address
The various combinations allow a memory operand to be
addressed in the following ways:
• as an 8 or 16 bit immediate operand
• relative to a segment register (CS, SS, DS, ES) using a
16 bit offset
• with an index register (BX, SI, or DI)
• relative to a base or index register (BX, BP, SI, or DI)
using an 8 or 16 bit offset
• with a base register (BX or BP) plus an index register
(SI or DI)
• relative to a base register (BX or BP) plus an index
register (SI or DI) using an 8 or 16 bit offset
Instruction Set
For every 8080 instruction, there is a corresponding 8086
instruction (or, in some cases, a short sequence of instructions)
to perform the same function. Nearly all instructions can
operate on either 8 or 16 bit quantities in either registers or
memory (push and pop are notable exceptions). And of
course, several additions and extensions have been made . . .
• An XLAT (translate) instruction searches a table to find
the corresponding value of an incoming variable. Once
found, this corresponding value is substituted for the
original value. Therefore, using the iteration control and
string primitives with the translate instruction, a task such
as translating a string of EBCDIC characters into ASCII
characters can easily be performed using only seven
instruction bytes.
• An LEA (load effective address) instruction automatically
computes the effective address of a memory operand.
• There are single instructions to add, subtract, multiply, or
divide signed or unsigned 8 or 16 bit operands in binary,
BCD, or ASCII, carried out in two’s complement form.
This allows easy implementation of multiple precision
algorithms.
• The CBW and CWD instructions convert (sign extend)
bytes to words and words to double words.
•Variable length shifts and rotates (using a count in CL) are
implemented.
• A set of one byte instructions use SI and DI as pointers to
a pair of byte or word strings (the pointers are optionally
automatically incremented or decremented after each
operation). These are the “string primitives” and during
their execution, the SI and DI pointers as well as the CX
count register are updated after each operation:
Move move source string to destination string
Compare compare strings
Search search destination string
Load load from source string
Store store (fill) destination string
• A REP (repeat) instruction automatically repeats a follow¬
ing string instruction (move, compare, etc.) for a specified
count in CS, or while or until the Z bit is set or reset.
•CALL, JMP, and RET instructions can transfer within the
current segment or to another segment. Calls and jumps
use relative addresses to allow position independent
(relocatable) code. Conditional transfers must be within
±128 bytes of the instruction. A return can automatically
pop a number of parameters off the stack.
•Various LOOP instructions perform a decrement of CX
and jump ±128 bytes depending on the result (and option¬
ally testing the Z flag as set by instructions in the loop).
•Software interrupt instructions provide efficient break¬
point and overflow handling.
• A WAIT for external interrupt instruction is automatically
re-executed at the end of interrupt handling to allow syn¬
chronization with external devices.
• An ESC (escape) instruction places memory operands on
the bus so that other processors can receive instruction
streams and use 8086 addressing modes.
•A LOCK instruction can precede any other instruction so
that while the instruction executes, other processors in a
multiple processor configuration are locked out and
cannot interfere. This allows easy implementations of test-
and-set or semaphore operations in software.
Speed
Both five megaFlertz and eight megaHertz clocks are supported.
At 5 MHz, one clock cycle is 200 nanoseconds; at 8 MHz, it is
125 nanoseconds. The fastest instructions, such as register to
register moves, take two cycles. The slowest instructions, such
as a signed 16 bit divide, take over 150 cycles.
Instruction execution is overlapped with the fetch of the
next instruction. In the 8086 up to six instruction bytes can
be accessed and queued prior to actual execution. The queue
forms the pipeline of instructions and time is saved because
the instructions are accessed while the instruction execution
portion of the microprocessor is busy, thus resulting in signifi¬
cantly improved operating efficiency in the microprocessor.
“Dead time” on the memory bus is greatly reduced, thus
Page 20 Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Number 27
306
allowing moderate speed, less expensive memories to be used
while still achieving high CPU performance. Intel consistently
claims ten times the “performance” of the 8080.
Interrupts
The reserved memory locations 0 through 3FF 16 are divided
into 256! 0 4 byte interrupt pointers, where each pointer cor¬
responds to an interrupt “type”. Every interrupt supplies an 8
bit type number, which is used to select the appropriate 4 byte
pointer. The pointer is interpreted as a 16 bit segment address
and a 16 bit offset in the segment, and control is transferred to
that address. The first 32 interrupt pointers are dedicated:
type 0: divide error
1: single step
2: non-maskable interrupt
3: breakpoint
4: overflow
5-31: reserved
The 8086 also provides software maskable interrupts. The
total overhead at each interrupt (for pushing flags, disabling
interrupts, transferring control, returning from the interrupt,
and so on), is 88 cycles.
Another feature afforded by the architectural enchance¬
ments of the microprocessor addressing capability is improved
input/output addressing. The improvement permits a maxi¬
mum of 65K bytes of I/O port space. The ports may be either
8-bit or 16-bit ports and the 16-bit ports may be located at
either odd or even addresses. Moreover, indirect I/O addressing
is now possible with the 8086, a feature not available on the
8080 or 8085.
Conclusion
The 8086 is a sophisticated device with a very large instruction
set. At one time, the various types of CPUs (micros, minis,
midis, and maxis) could be differentiated by speed and
addressing capabilities, but the trend is to minimize those dif¬
ferences. The 8086 may be “micro” in size or price, but
certainly not in performance.
For $360, Intel is marketing the SDK-86 System Design
Kit, a complete single board system including CPU, 8K
ROM, 2K RAM, and I/O. The board also contains an inter¬
active LED display and keyboard. The system monitor is
contained in ROM and there is a wire-wrap area for custom
interfacing. All bus and parallel I/O signals are TTL com¬
patible and serial I/O is 20/rA current loop TTY or RS232.
The system comes with a comprehensive design library.
TINY-C’ INTERPRETER FOR 8080 AND PDP-11
News Release Received: 78 June 22
An interpreter for a subset of the C structured program¬
ming language which runs on both DEC PDP-11 and Intel
8080 processors is available from Tiny-c Associates. The tiny-c
Owner’s Manual includes a complete reference description of
the language, a tutorial walkthrough of a training program, lots
of sample programs including comments on their programming
style, and a description of the Program Preparation System. It
also includes commented source code listings of both the 8080
and the PDP-11 interpreters, and a chapter on how the inter¬
preter works.
Tiny-c is intended primarily for the education and hobbyist
markets. The tiny-c language handles integer and character
data, and arrays of either type. Other features include com¬
pound statements, if-else and while statements, global and
local variables, pointer variables, and functions. Functions may
have arguments and may return results. Recursion is allowed.
The interpreter also recognizes calls to functions written in
machine language. These, too, may have arguments and return
results. A minimum of 16K bytes of memory is recommended
to run tiny-c.
The package includes a Program Preparation System with
which the user can write, edit, run, debug, store, recall, and
link tiny-c programs. The PPS includes a standard library of
tiny-c software tools. The PPS is written in tiny-c. Thus it
serves as an example of a significant use of tiny-c, and is also
easily adapted to a user’s or operating system’s requirements.
The Owner’s Manual is available for $40 from Tiny-c Asso¬
ciates, P.O. Box 269, Holmdel, New Jersey 07733. Machine
readable copies of the interpreter are available separately on
several formats of tape and disk.
ERROR MESSAGE MANUAL
FOR NORTH STAR DOS
News Release Received: 78 June 15
The NORTH STAR DISK SYSTEM ERROR MESSAGE
SUMMARY is for users of the North Star Computers floppy
disk system. This manual is a compilation of all DOS and
BASIC error messages given by the North Star system. The
manual gives the meanings of these messages in easily under¬
stood terms. Numerous examples extracted from programs
serve to illustrate what program errors cause these messages
so they can be avoided. The manual serves as a reference
source in debugging programs when occurrence of these
messages appears. Also illustrated are error messages resulting
from improper DOS input commands as well as BASIC com¬
mands. It is available from HSC COMPUTER SERVICES,
LTD., P.O. Box 43, Brooklyn, NY 11236, by sending check or
money order in amount of $5.00 plus 50 cents shipping and
handling, available from stock.
MKB-2 KEYBOARD
News Release Received: 78 June 26
The MKB-2 Keyboard by MicroAge, is designed for use
with the new 64 and 80 character display video boards.
Included as standard in the MKB-2 are a numeric key pad,
upper and lower case, cursor control keys, 2-key rollover,
and auto repeat on all keys. The MKB-2 is assembled in a
heavy duty steel case with parallel interface, strobe or pulse,
on-board regulation (5v, 12v), complete with standard DB25S
connector, and black double-injection molded keys. List:
$149.00 Contact MicroAge, 1425 W 12th Place #101, Tempe,
AZ 85281;(602) 967-1421.
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 21
307
A IK UTILITIES PACKAGE
FOR THE Z-80
BY LES HANCOCK
305 Lexington Ave. 7-C
New York, NY 10016
This is a companion piece to the IK Debugger, written to
run on a Digital Group Z-80 system with ZE audio ROM,
TVC-64 interface and TVC-64 monitor (see DDJ no. 24,
p. 12). Starting the program causes it to clear the TV screen
and print this menu:
TVC-64 UTILITIES
0 MONITOR
1 SEARCH
2 COMPARE
3 MOVE
4 HEX MODE
You can pick any item on the menu by keying in a number
from 0 through 4. (Anything else is ignored.) 0 returns control
to the monitor and 4 sets hex mode for routines 1,2 or 3. (De¬
fault mode is octal.)
As soon as one of the three utilities is chosen, the screen is
erased and a new banner appears. You’ll be prompted for the
appropriate addresses and data entries. Carriage returns are not
used to signal the end of an entry, except in the case of the
target string for item 1. When a utility has all the parameters
it needs, it runs to completion, then waits for you to press a
key. The space bar restarts the utility; any other key sends you
back to the menu, reinitializing the program and resetting oc¬
tal mode. There’s no way to recover from typing errors. You’ll
have to use the RESET switch to abort, then start over.
Item 1 is a string search utility. It searches any range of
memory for a string up to 9 bytes in length. Bytes are speci¬
fied in octal/hex notation or in ASCII, and any byte in the
string (except the first, of course) can be left “wild”—in other
words, you can search for discontinuous strings.
This last feature is really handy. Suppose you’re looking for
jumps to page zero. There are 256 possible 3-byte strings to
hunt for: C3 00 00, C3 01 00,... C3 FF 00. You can find all
of them in one go by specifying the target string as C3 // 00,
where // is a wild byte.
The syntax of item 1 is as follows:
SEARCH A-B FOR STRING
A?aa
B?bb
STRING?
where aa and bb are two 16-bit addresses entered by the user.
As for the target string itself, you can define it in either of two
entry modes:
1. Octal or hex notation. Simply type in a string of bytes in
octal or hex. Don’t try to separate them; the program prints
a blank after each byte entered. To specify a wild byte, press
the slash key (/). The slash will be echoed twice or three
times, depending on whether you’re using hex or octal. To ter¬
minate the string enter a carriage return. If your string is 9
bytes long no c/r is necessary; the program will take off as
soon as the last number is typed.
2. Text strings. There is provision for entering text directly in
ASCII, but it’s necessary to distinguish between the two
ASCIIs supported by the Digital Group. One is the code we all
know, with the high bit off. The letter A is hex 41, the numer¬
al 1 is hex 31. The other ASCII, with bit 7 set for use as a
strobe, codes the letter A as hex Cl, the numeral 1 as hex Bl.
Where you want to search for text with the high bit on, enter
a single quotation mark (’), then type in the characters. For
straight ASCII, enter a double quotation mark (”), then the
text. No wild bytes permitted in either case.
The address of the first byte of each occurrence of the
string will be displayed at the console. If there are enough ad¬
dresses to fill the screen, output ends and the program waits
for a keypress. Then it erases the screen and goes ahead.
Some examples:
SEARCH A-B FOR STRING
A7 000000
B7006000
STRING7315 372 000 (c/r)
000350 001237 002016 002073 002101 003232 003324 004176
004262 004277 004316 004361
SEARCH A-B FOR STRING
A? 000000
B7000377
STRING?315 _/// 000 (c/r)
000114 000130 000133 000153 000156 000162 000170 000214
000223 000226 000350 000357
SEARCH A-B FOR STRING
A? 05^ 00 - hex mode
B? 05 FF
STRING? 'Assembler < 9 bytes, no c/t needed
05 9A
SEARCH A-B FOR STRING
A7000000
B7 010000
STRING? "Assemble (c/r)
NONE
Item 2 is a routine that compares corresponding bytes in
two ranges of memory. It reports out every mismatch, giving
addresses, the bytes themselves in octal or hex, and the ASCII
Page 22
308
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
equivalent of each byte. (Note: the Digital Group’s TVC-64
board uses an MCM6571L character generator with special
symbols and Greek letters below the blank.) Output is slanted
across the screen for better legibility. As with item 1, you can
clear a filled screen by touching anything on the keyboard.
An example:
COMPARE A - B TO C - D
A?010033
B7 010045
C7005255
(erases screen)
010033=311='I 005255=343'c
010034=311='I 005256=357=’o
010035=311=' I 005257=360='p
010036=301='A 005260=371='y
010037=377= 005261=000="*<
010040=310='H 005262=000="*<
010041=310='H 005263=000="°^
010042=310='H 005264=000="
010043=300=' @ 005265=000="K
010044=276=’> 005266=000="*4
010045=301='A 005267=000="*<
Item 3 copies a block of bytes from one range of memory
to another. You supply the starting and ending addresses that
define the source block, then the starting address for the new
block. The utility transfers the data and prints the new ending
address.
MOVE A - B TO C - D
A7 000000
B7001000
C? 100000
D? 101000 - this line printed by the
program itself after
the move is completed
Footnotes To The Code
1. Line 180: The TVC-64 monitor contains a routine, here
called TVE, for printing a string of high-bit ASCII charac¬
ters at the TV console. Before calling it the user sets HL to
point to the first byte in the string. A rubout in the string
(hex FF) will erase the screen; a value n from 1 through
hex 7F will print n spaces; an empty byte (0) ends the
string.
2. Line 200: The monitor subroutine NUMIN gets a byte from
the keyborad, entered by the user in octal or hex notation.
(See note #3.) But what if we already have the first of the
two hex or three octal digits that represent a byte? In that
case a call to FINISH will dive into the middle of NUMIN
and come back with the rest of the byte.
3. Lines 310, 5910: By Digital Group convention, the byte at
hex address 01A7 is a mode code. If it’s ASCII ‘H’, the
current mode is hex; if not, octal.
4. Line 1570: SEARCH keeps its not-found flag and its
paging counter in alternate registers E and B respectively.
The counter is initialized to 96 because the first page of ad¬
dresses is printed below the routine’s headers and parame¬
ters. If the first page overflows, the counter is reset to 127
for subsequent pages. (Space is left for a slash to indicate
that there’s more to come; hence the odd number.)
The Code Listing
67E9
0100
• • •
• •
87E9
0110
• IK UTILITIES* BT L6S
M4NC0CK •
67E9
0120
•
•
•
6769
01)0
• VERSION
OF M4Y 12*
1971 •
6769
0140
• • •
• •
6769
0159
•
799#
9160
ORO
7000H
7999
01 70
•
7999
0100
TVE
E0U
0200H
SEE NOTE #1
7999
0190
MONTH
E0U
0500H
NON 1 TOR ENTRY 4D0R
7999
0200
FINISH
E0U
0449H
SEE NOTE 02
7999
0210
KETB0
E0U
0 14 8W
6ETS 1 8TTE FROM KET80
7999
0220
E84SE
E0U
00E6H
ER4SES TV SCREEN
7900
0230
NUMIN
E0U
9446H
GETS HEX OR OCT BYTE
7000
0240
•
FROM KEYBO
7000
0250
NUM0UT
EOU
02 46H
PRINTS BYTE 4S HEX OR
7900
0260
•
7000
0270
• INITI4LI24TI0N
7900
0280
•
7000
31
00
70
0290
START
L0
SP.START
SET ST4CK POINTER
7903
36
CF
0300
LD
A * • 0 *
SET MODE TO 0CT4L
700b
32
4 7
01
9310
L0
(0147H)»A
SEE NOTE 03
7906
21
78* 73
0320
ST4RT2
L0
ML »UT1L
CLEAR SCREEN AND PRINT
700b
CO
00
02
0330
C4LL
TVE
MENU OF ROUTINES
7906
36
81
0340
L0
A * ’ 1 '
70 10
CD
47
70
0 3 50
C4LL
NUNS
7913
21
36
73
0360
L0
HL*SRCH
7916
CO
00
02
0370
C4LL
TVE
7019
06
36
0380
L0
8*620
70 IB
CO
91
70
0390
C4LL
LINE
70 IE
36
62
0400
L0
4* '2*
7020
CO
47
70
0410
C4LL
NUNS
7023
21
30
73
0420
LO
HL»CMPR
7926
CO
00
02
0430
C4U
TVE
7029
16
30
0440
L0
8*610
702B
CO
01
70
0450
C4LL
LINE
7026
36
83
0460
L0
4* '3'
7030
CO
47
70
0470
C4LL
NUNS
7033
21
45
73
0460
L0
ML»MV
7036
CD
00
02
0490
C4LL
TVE
7039
06
40
0500
LO
8*640
7030
CO
81
70
0519
C4LL
LINE
703E
36
84
0520
LO
4* *4 •
7040
CO
47
70
0530
C4LL
NUNS
7043
21
44
73
0540
LO
ML *MX
7046
CD
00
02
0550
C4LL
TVE
7049
0660
•
7i«9 «57» • SELECT SOUTINE
7049 9580 • TO BE USED
7049
0590
•
7049
CO
48
01
0600
INPUT#
CALL
KEYBO
OET A BYTE
704C
FE
60
9610
CP
080 M
IF NOT AN ASCI 1
704E
38
F 9
0620
JR
C•1NPUT0
NUMBER 0<«N<S*
70 50
FE
65
0630
CP
0B5H
6ET ANOTHER
7062
30
F 5
0640
JR
NC * INPUT#
70 54
E6
0F
0650
ANO
0FH
CONVERT TO BINARY VALUE
7056
07
0660
RLCA
TINES 2
70 57
6F
0670
LO
L*A
6ET RESULT INTO HL
70 58
26
00
0660
LD
H*0
7054
11
65
70
0690
LO
OE • TABLE
7MD
19
0700
ADO
HL»DE
ADO TABLE START ROOM
70 5E
22
62
70
0710
LD
( INNE0)»ML
STORE AT INNEO
7061
0720
D8
2AH
INSTRUCTION! LOAO
24
7062
0730
•
HL EXTENOEO
7062
0 740
IHNEO
ON
TABLE
OPERANO FOR INSTRUCTION
65
70
7064
£9
0750
JP
(HL)
JUMP TO SELECTED ROUTINE
7066
076#
•
7066
0770
•
TABLE OF
ENTRY POINTS
7065
0780
•
FOR
UTILITY ROUTINES
7065
0790
•
7065
0000
TABLE
ON
MONTR
00
05
7067
0010
ON
SEARCH
B4
70
7069
0820
ON
CONPAR
56
72
7068
0830
ON
MOVE
FO
71
7060
0840
ON
HEXNOO
26
73
70 6F
0850
70 6F
0869
SUBRS AT
THE F0LL0NIN6
70 6F
08 70
LABELS! •
SPACE* PRINTS
70 6F
0880
1 BLANK ON TV SCREENS
70 6F
0890
■QUEST* PRINTS CHARACTER
70 6F
0900
IN ACCUMULATOR* THEN
•?■»
706F
0910
■TV"
PRINTS CHARACTER
IN
70 6F
0920
ACCUMULATOR
70 6F
0930
706 F
F5
0940
SPACE
PUSH
AF
7070
3E
40
0950
LO
A *0A0H
70 72
18
06
0960
JR
SPC
70 74
CO
79
70
0970
OUEST
CALL
TV
7077
3E
BF
0980
QUEST 1
LO
A.*?*
7079
F5
0990
TV
PUSH
AF
70 74
03
00
1000
SPC
OUT
0
70 7C
AF
1010
X OR
A
70 70
03
00
1020
OUT
0
707F
FI
1030
POP
AF
7060
C9
1040
RET
706 1
1050
•
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 23
309
7081
1060
•
SUBR
TO PRINT f OF
BLANK
7114
2170
•
ELSE 1ST BY Tt INPUT*
7081
1070
•
SPACES 1 NO 1CA T60 BY V41UE
7114
2180
•
IS BYTE ' 7
708 1
1080
•
IN 6
7114
20
06
2190
JR
Z *SETL 1 T
YES; STRING KILL NF
7116
220#
•
STRAIGHT ASCI 1
708 1
CO
6F
70
1100
LINE
CALL
SPACE
7116
FE
A2
2210
CP
0A2H
IS IT-?
7084
10
F6
1110
OJNZ
LINE
7118
20
09
2220
JR
N?.NUMBER
7086
C9
1120
RET
711A
ce
CB
2230
SET
1 *E
YES; STRING IS ASCI 1
7087
1130
711C
2240
•
K1TH HIGH BIT ON
7087
1140
SUBR
TO PROMPT FOR
TKO
711C
CB
FB
2250
setlit
SET
7 *E
708 7
1150
2-BYT6 V4LU6S* RETURNING
7111
CO
79
70
2260
CALL
TV
ECHO • OR ■
708 7
1160
THEN
IN HL ANO DE
7121
18
09
2270
JR
INPUT
6ET 1ST BYTE OF STRING
1170
7123
F 6
60
2200
NUMBER
CP
0A0H
BYTES THAT ARRIVE HERE
708 7
36
Cl
1180
66 T48
LO
A* 'A'
7125
2290
•
ARE NUMERIC; IF BLANK
7068
CO
74
70
1190
CALL
OUEST
7125
28
05
2300
JR
Z » 1 NPUT
I6N0RE THEM
708C
CO
46
04
1200
CALL
NUN 1 N
7127
FE
AF
2310
CP
• /'
IS THIS A ■KILO" BYTE?
708F
67
1210
LO
H » A
7129
20
2A
23 20
JR
NZ*NTKIL0
7080
CO
4b
04
1220
CALL
NUNI N
7126
7093
6F
1230
LO
L * A
7128
2340
• BEGIN KIL0-8YTE ROUT
INE
7094
0b
38
1240
LO
B * 560
7128
2350
•
7096
CO
81
70
12S0
CALL
LINE
7128
M
2360
LO
4*0
OFT 0YTE COUNT
7099
36
C2
1260
LO
A •' B '
712C
F 6
09
2370
CP
90
IS THIS 1ST BYTE?
7098
CO
74
70
1270
CALL
QUEST
7126
CA
00
70
2 380
JP
Z .START
YES* ABORT
709E
CO
46
04
1280
CALL
NUMIN
7131
30
239#
DEC
A
OEC BYTE COUNT
704 1
67
1290
LO
D»A
7132
0?
2400
RLCA
7042
CO
46
04
1300
CALL
NUMIN
7133
07
2410
RICA
7046
5F
1310
LO
E*A
7134
07
2420
RLCA
7046
C9
1320
RET
7135
F 6
Cb
2430
OR
0C6H
7047
1330
713?
32
36
71
2440
LO
(81 T0).A
6 NOK CONTAINS OPERAND
7047
1340
SUBR
TO PRINT ASCI 1
7136
2450
•
OF FORTHCOMING BIT-SET
7047
1350
NUMBER IN
A* THEN
ONE
7136
2460
•
INSTRUCTION
7047
1360
BL4NK SPACE
71JA
21
FC
71
2470
LO
HL *MASK
704 7
CO
79
70
1370
CALL
7130
2400
oe
0CBM
INSTRUCTION! SET <HL)*N
7047
1380
SUMS
TV
ce
7044
CO
6F
70
1390
CALL
SPACE
7136
2490
81 T#
OS
1
MHERE THIS BYTE IS N
7040
C9
1400
RET
713F
2500
•
7046
1410
•
713F
2510
• KMEN
BYTE
COUNT IS 8
» THE ABOVE INSTRUCTION
7046
1420
•
SUBR
TO K4IT FOR KEYPRESS*
713F
2520
• KILL
BE SET (ML)♦7;
KHEN 7* IT KILL BE
7046
1430
•
THEN
COMPARE INPUT
K1 TH ASCI 1 BLANK
713F
2530
• SET
( HL ) *«
6; UNDSOKEITER
7046
1440
•
713F
2540
•
7046
CO
48
01
1450
KEY PR
CALL
KEYBO
713F
36
AF
2 550
LO
A* •/'
ECHO SLASH TKICE
7081
F 6
40
1460
CP
0 A0H
7141
CO
79
70
2560
CALL
TV
7083
C9
1470
RET
7144
CO
79
70
2570
CALL
TV
7084
1400
• •
• * •
• • • •
• •
7147
36
A 7
01
2580
LO
A*(01A7M)
IF MODE IS OCTAL* ECHO
7084
1490
ROUT
INE TO SEARCH ■
7 14 A
FE
C0
2590
CP
•H*
ANOTHER
7084
1600
SPEC
IF IEO
RANGE OF
MEMORY
714C
28
05
2600
JR
Z.MEX
7084
1510
FOR .
A GIVEN STRING
714E
3E
AF
2618
LO
A * * / '
7084
1520
7150
CO
79
70
2620
CALL
TV
7084
1530
INITIALIZATION
7153
18
03
2630
HEX
JR
NEXT5
7084
1540
7155
CO
A9
04
2640
NTKILO
CALL
FINISH
COMPLETE the HEX or
7084
4F
1650
SE4RCM
XOR
A
clear kilo-byte flag
7158
2650
•
OCTAL BYTE l ECHO 1T
7085
32
FC
71
1560
LD
(MASK)»A
7158
CO
6F
70
2660
NEXT5
CALL
SPACE
7088
06
60
1570
LO
B *960
SEE NOTE #4
7158
00
77
00
2670
LOAD
LO
( IX*#)*A
LOAO BYTE INTO BUFFER
7064
CB
C3
1580
SET
0*E
SET NOT-FOUNO FLAG
715E
DO
28
2680
DEC
IX
OECR POINTER
708C
00
1590
EXX
7160
15
2690
DEC
0
OECR COUNTER
7080
CO
66
00
1600
CALL
ERASE
CLEAR SCREEN ANO
7161
20
99
2700
JR
NZ * 1NPUT
IF 9 BYTES NOT USED
70 C0
21
36
73
1610
LO
HL*SRCM
PRINT BANNER
7163
2718
•
YET* GET ANOTHER
70C3
CO
00
02
1620
CALL
TVE
7163
2728
•
70C6
21
53
73
1630
LO
HL»A0
7163
2738
• SPACE TO I
NEXT LINE
70C9
CO
00
02
1640
call
TVE
7163
2748
•
70CC
21
SC
73
1650
LO
ML »F OR
7163
3E
09
2758
ENOPUT
LO
A *90
6ET NO* OF BYTES
70CF
CO
00
02
1660
CALL
TVE
7165
92
2768
SUB
0
USEO INTO 0
7002
21
61
73
16 70
LO
HL *STRNG
7166
57
2778
LO
0 • A
7005
CO
00
02
1680
CALL
TVE
7167
ce
78
2780
BIT
7*E
KAS INPUT ASCII?
7008
06
26
1690
LO
8*460
7169
20
04
2790
JR
nz.short
7004
CO
81
70
1700
CALL
LINE
7168
07
2888
RLCA
TINES 4
7000
1710
•
716C
07
2818
RLCA
7000
1720
•
GET 1
>ARAMETEHS
7160
06
01
2020
SUB
1
MINUS 1
7000
17J0
•
716F
C6
08
2030
SHORT
ADO
90
PLUS 8
7000
CO
87
70
1740
CALL
66 TAB
GET SEARCH RANGE
7171
EO
44
2840
NE6
7060
65
1750
PUSH
HL
SEE N6XT9
7173
Cb
40
2860
AOO
640
SUBTRACTED FROM 64
7061
65
1760
PUSH
HL
7175
47
2860
LO
B* A
PRINT THAT MANY
7062
06
1770
PUSH
OE
7176
CO
81
70
2070
CALL
LINE
BLANKS
7063
06
33
1780
LO
8*510
7179
2880
•
7065
CO
81
70
1790
CALL
LINE
7179
2890
• SET
UP FOR SEARCH
7068
21
61
73
1800
LO
HL»STRNG
PROMPT FOR STRING
7179
2900
•
7066
CO
00
02
1810
CALL
TVE
7179
El
2910
NEXT6
POP
HL
GET TOP Of RANGE
7066
CO
77
70
1020
CALL
QUEST 1
71 7 A
Cl
2920
POP
BC
1 START OF RAN6E
70F 1
11
00
09
1830
LO
DE *0900H
SET 0 TO 9 (MAX BYTE
7178
87
2930
OR
4
RESET CARRY FLA6
70F4
1840
•
COUNT) ANO SET E TO
717C
2940
•
(OR NEXT INSTRUCTION
00
21
45 73
1850
ZERO
717C
2950
•
MIGHT BLOK UP)
70F 4
1860
LO
IX* INBUF
6ET INITIAL INPUT
717C
60
42
2960
SBC
HL*8C
GET SIZE OF RANGE
70F8
00
65
1070
PUSH
IX
BUFFER ADDRESS
717E
65
2970
PUSH
ML
(KMICH GOES
FO
61
POP
IT
717F
Cl
2900
POP
BC
INTO 90
7180
03
2990
INC
BC
PLUS 1 (IN CASE THE
70FC
1900
INPUT OF :
STRING BEGINS. FLAGS AS FOLLOKS.
7101
3000
•
STRING FOUNO IS
70FC
1910
BIT
7 OF
E IS SET
IF
INPUT ■ ASCI 1 STRING*
7181
3010
•
COTERMINOUS KITH
70 FC
1920
0THER8ISE
INPUT IS
ASSUNEO TO BE A SERIES
7181
3020
•
THE RANGE SET)
70FC
1930
OF BYTES
IN HEX OR
octal representation.
7181
El
3030
POP
HL
START AOOR INTO HL
70FC
1940
7182
5A
3040
LO
E»0
SAVE BYTE COUNT IN E
70FC
195#
IF THE FIRST BYTE
input is ■ THEN the
7183
3050
•
70FC
I960
USER
KANTS TO SEARCH
FOR ASCI 1 BYTES
7183
3060
• SEARCH TILL FIRST BYTE OF
70F t
197#
KITH
THE
HIGH BIT
on*
IN THAT CASE
7183
3070
• STRING IS
FOUND* OR
TILL
70FC
1980
BIT
1 OF
E IS SET*
7183
3000
• SEARCH RANGE IS EXHAUSTED
70FC
1990
7183
3090
•
70FC
2000
IF THE FIRST BYTE
INPUT IS • THEN THE
7183
53
3100
L00K2
LO
D»E
BYTE COUNT TO 0
70FC
2010
USER
KANTS TO SEARCH
FOR STRAIGHT
7184
FD
E5
3110
PUSH
IY
RESTORE POINTER
70FC
2920
ASCII BYTES* KITH
THE
HIGH BIT OFF*
7186
00
El
3120
POP
IX
TO STAR T OF BUFF
70FC
2030
IN THAT CASE BIT 1
OF
E IS ZERO.
7188
00
7E
00
3130
LO
A • (1X*0)
GET 1ST BYTE
70FC
2040
7188
60
• i
3140
CPIR
SEARCH FOP IT
70FC
CO
48
01
2050
INPUT
CALL
KEYRO
GET BYTE
7180
28
07
3150
JR
Z»NPXT7
FOUNO ITI
70FF
F 6
80
2060
CP
80m
IS IT C/R?
718F
09
3160
BCZERO
Exx
OUT OF RANGE: CHECK
7101
26
60
2070
JR
Z»ENDPUT
YES* END INPUT
7190
CB
43
3170
81 ?
0»E
NOT-FOUND FLAG*
7103
ce
78
2080
BIT
7 *E
IS STRING LITERAL?
7192
20
59
3180
JR
NZ.NONE
TAKE APPROPRIATE
7105
28
06
2090
JR
Z »NOTL 1 T
7194
18
50
3190
JR
FIN
EXIT
7107
CO
79
70
2100
CALL
TV
YES* ECHO IT
7196
3200
•
7104
CB
48
2110
BIT
1»E
IS IT STRAIGHT ASCI 1?
7196
3210
• 1ST
BYTE
KAS FOUNO;
SEARCH
710C
28
40
2120
JR
Z*LOA0
NO* LOAD AS IS
7196
3220
• FOR
SUCCESSIVE BYTES
IN STRIN6
7106
66
7F
213#
ANO
7FM
ELSE KILL HIGH 81T
7196
3230
•
7110
18
49
2140
JR
LOAD
7196
15
3240
NEXT7
OEC
0
OECR BYTE COUNT
7112
F6
47
2150
NOTH T
CP
0 A 7 H
BYTES THAT ARP 1VE HERE
7197
28
25
3250
JR
Z.PRINT2
FOUNO KMOlE STRINfll
7114
2160
•
ARE EITHER NUMERIC OR
7199
78
3260
LO
A *8
BC * •?
Page 24
310
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
7T9A 8 1
7198 26
7190 C5
719E
719E 78
719F 92
7TA0 47
7141 34
7144 96
7146 26
7147 97
7146 19
7144 C8
714C
714C Cl
7140 00
714F DO
7162 26
7184 23
7166 96
7166 16
7108 ED
71 BA 29
710C 16
71BE
7186
716E
7166
710E 6b
71BF 08
71C9 09
7ici ce
71C 3 19
71C5
71C8 36
71C7 CO
71CA CO
71C0 CO
7109 96
7102 09
7103 26
7104 10
7108 29
7107 SC
7106 CD
71 OB 50
71 DC CO
710F CO
71E2 CO
7165 01
71E6 61
716 7 78
7169 81
71E9 29
71E8 16
7160 21
71F9 CO
71FJ CO
71F6 CA
71F 9
71F9 C3
71FC
71F0
71F D
71F0
71F0
71F0 CO
7299 21
7293 CO
7296 21
7299 CO
720C 21
720F CO
7212 06
7214 CO
7217
7217
7217
7217 CO
7214 13
7216 05
721C E5
7210 01
7216 El
72IF EO
7221 05
7222 E5
7223 06
7225 CO
7228 3E
7224 CO
7220 CO
7230 67
7231 CO
7234 6F
7235 Cl
7236 El
7237
7237
7237
7237 EO
7239
7239
7239
7239
7239 06
723B CD
7236 21
7241 CO
7244 16
7245 05
Number 27
3270
OR
C
7246
5 A
4380
LO
E»D
F 2
326#
JR
2 »BCZERO
YES* YOU'RE OONE
7247
CO
46
02
4390
CALL
NUMOUT
3290
PUSH
BC
IS NEXT BYTE ■BUD"?
7244
01
4400
POP
OE
3300
•
LET'S FIND OUT
724B
CD
46
02
4410
CALL
NUMOUT
3310
LO
A »E
NUMBER OF BYTES IN STRING
72 4 E
CO
AE
70
4420
CALL
KEYPR
BAIT FOR KEYPRESS
3320
SUB
0
MINUS CURRENT BYTE COUNT
7251
28
AA
4430
JR
Z*MOVE
IF SPACE BAR*
3330
LO
B * A
RESULT IS SHIFT COUNTER
7253
4440
•
MOVE AGAIN
FC
71
3340
LO
A »(MASK )
GET MASK TO BE SMIFTEO
7253
C3
00
70
4450
JP
START
ELSE BACK TO MENU
3350
ROTATE
OEC
B
ROTATE MASK LEFT 0 IF
7256
4460
• • •
• • •
03
3360
JR
2 * TES T
NEXT BYTE IS 2ND IN
7256
4470
• ROUTINE TC
1 COMPARE TNO
33 70
RICA
STRING* 1 IF NEXT BYTE
7256
4480
• BLOCKS OF
MEMORY AND
F 4
3380
JR
ROTATE
IS 3RD* ETC
72 S6
4490
• DISPLAY MISMATCHES
7F
3390
TEST
BIT
7 » A
IF BIT 7 IS SET* NEXT BYTE
7256
4601
•
3400
■
BILL BE 'BUD*
7266
4510
•
3410
POP
BC
7256
4520
• INITIALIZATION
28
3420
OEC
IX
OECR POINTER
7256
4530
•
7E
00
3430
LO
A»( 1K♦• )
GET NEXT BYTE
7256
f 1
00
00
4540
COMPAR
LO
6C*0
SET NOT-FOUNO FLAG
04
3440
JR
2»N0SKIP
IF BYTE BAS B1LO* 60
7259
C5
4550
PUSH
BC
1 PAGING COUNTER
3450
INC
ML
RIGHT ON TO NEXT
725A
CO
€6
00
4560
CALL
ERASE
CLEAR SCREEN ANO
3469
OEC
BC
7260
21
30
73
4570
LO
HL*CMPR
PRINT BANNER
06
34 70
JR
NEXT 7
7260
CO
00
02
4560
CALL
TVE
41
3489
NOS*IP
CPI
FIND NEXT BYTE OF
7263
21
53
73
4590
LO
HL»AB
04
3490
JR
2 »NEX T 7
STK1NG?
7266
CO
00
02
4600
CALL
TVE
C5
3500
JR
LOOK2
If NOT* START OVER
7269
21
60
73
4610
LO
HL • TO
3510
•
726C
CO
00
02
4620
CALL
TVE
3520
• PRINT AODRESS OF
726 F
06
28
4630
LD
B.430
3530
• STRIN6 BHEN FOUNO
727 1
CD
81
70
4640
CALL
LINE
3540
•
7274
4650
•
3559
PRINT2
PUSH
ML
7274
4660
• GET 1
PARAMETERS
3560
PUSH
OE
7274
4670
•
3870
EX X
7274
CO
87
70
4680
CALL
GETAB
GET START
83
3588
603
RES
0 »E
RESET NOT-FOUND FL46
7277
06
38
4690
LO
6*560
1 END AOOR
00
3590
DJN2
NEXT8
OECR L OC A T 1 ONS “PR 1 NTE'J
72 79
CO
81
70
4700
CALL
LINE
OF BLOCK 1
3609
•
COUNTER* SKIP ON 0
727C
3E
C3
4710
LO
A * ' C 1
4F
3610
LO
A * • / •
PRINT /
727E
CO
74
70
4720
CALL
OUEST
GET START
79
70
3620
CALL
TV
728 1
CO
A6
04
4730
CALL
NUMIN
AOOR OF
48
91
3630
CALL
KETRD
BAIT FOR KEYPRESS
7284
F 5
4740
PUSH
AF
BLOCK 2
66
9 0
3640
CALL
ERASE
CLEAR SCREEN
7285
CO
A6
04
4750
CALL
NUMIN
INTO IY
7F
3650
LO
8* 1270
RESET COUNTER
7288
Cl
4760
POP
BC
3660
NEXT8
EXX
7289
4F
4770
LO
C » A
3670
8AKUP
DEC
ML
GET A DDR OF 1ST BYTE
728A
C5
4780
PUSH
BC
3689
OEC
E
IN STRING FOUNO
728B
F 0
El
4790
POP
IY
FC
3690
JR
NZ »BAXUP
7280
4800
•
3790
LO
E • H
PRINT ADDRESS
7280
48 10
• COMPARE BYTE N FROM
BLOCK 1
46
02
3710
CALL
NUMOUT
7280
4820
• BITH
BYTE
N FROM BLOCK 2; IF
3720
LO
E *L
7280
4830
• NOT
IDENTICAL* PRINT
ADDRESSES
46
02
3730
CALL
NJMOUT
7280
4040
• ANO
PRINT
EACH BYTE
AS HEX OR
6F
70
3740
call
SPACE
7280
4850
• OCTAL AND
AS ASCII
6F
70
3750
CALL
SPACE
7280
46 60
•
3760
POP
OE
7280
7E
4870
LOOK
LO
37 70
POP
ML
728E
FO
BE
00
4880
CP
<IY*0)
ARE BYTES EQUAL?
3760
LD
A »8
DOES THIS FIND
7291
20
00
4890
JR
NZ *FOUND
3790
OR
C
COINCIDE BITH ENO
7293
23
4900
NEX00
INC
HL
YES* BUMP POINTERS
98
3610
JR
NZ»LQ0K2
OF RAN6E? IF SO*
7294
FO
23
4910
INC
IY
96
381#
JR
FIN
STOP* ELSE SEARCH AGAIN
7296
05
4920
PUSH
OE
SUBTRACT BLOCK 1•S
68
73
3829
NONE
LD
HL»N0N
PRINT “NONE"
7297
E6
4930
EX
OE *HL
POINTER FROM
09
92
38 30
CALL
TVE
7298
EO
52
4940
SBC
ML » OE
BLOCK 1 ENO A00«
46
70
3840
FIN
CALL
KEYPR
BAIT FOR KEYPRESS
729A
EB
4950
EX
OE*ML
84
70
38 50
JP
2»SEARCH
IF SPACE BAR IS
729b
01
4960
POP
OE
3860
•
PRESSEO* SEARCH AGAIN
729C
38
2E
4970
JR
C*ENOALL
IF PTR ■> ENO* OONE
00
70
3870
JP
START
ELSE BACK TO inf MENU
729E
18
EO
4980
JR
LOOK
OTHERBISE CONTINUE
3880
MASK
OS
1
72A0
4990
•
38 90
• • • .
• • •
72A0
5000
• SUBR
TO PRINT
3900
* ROUTINE TO MOVE
72AI
5010
• BYTES THAT DON'T MATCH
3910
• A BLOCK IN MEMORY
72A0
5020
•
3920
•
72A0
Cl
5030
FOUNO
POP
BC
POP PA6IN6 COUNTER
66
00
39 30
MOVE
CALL
ERASE
CLEAR SCREEN AND
72A1
CB
41
5040
BIT
0*C
IF BIT 0*C IS ZERO*
45
73
3940
LO
ML * MV
PRINT BANNER
72A3
5050
•
THIS IS THE FIRST
09
02
3950
CALL
TVE
72A3
5060
•
MISMATCH FOUND
53
73
3960
LD
ML »A8
72 A3
28
06
50 71
JR
NZ•ONGO
00
02
3970
CALL
TVE
72A5
CO
E6
• 0
5080
CALL
ERASE
so be clear screen.
60
73
3980
LD
ML • T 0
72A8
01
01
0F
5091
LO
BC*0FfTM
SET PAGING COUNTER
80
02
3990
CALL
TVE
72 AB
5100
•
TO ISO C SET FLAG IN
2F
4000
LO
8*470
72A8
5110
•
C TO SHOB THAT THE
91
70
4010
CALL
LINE
72AB
5120
•
2 BLOCKS ARE NOT
4020
•
72 AB
5130
•
IDENTICAL
40 30
• OET PARAMETERS
72AB
C5
5140
ONGO
PUSH
BC
4040
•
72AC
E5
6150
PUSH
HL
87
70
4050
CALL
6ETA8
GET START
72 AO
05
5160
PUSH
DE
4069
INC
OE
ANO ENO
72AE
CO
E0
72
5170
CALL
PRINT
PRINT BYTE t AOOR
4170
PUSH
OE
ADDRESSES
7281
5180
•
FROM BLOCK T
4080
PUSH
HL
FOR BLOCK
728 1
FO
ES
6190
PUSH
IY
4080
POP
OE
CALCULATE SIZE
72B3
El
5200
POP
HL
4100
POP
ML
OF BLOCK
72B4
CO
E0
72
1210
CALL
PRINT
THEN FROM BLOCK 2
52
41 10
sec
ML » OE
7287
16
20
5220
LO
8*320
4120
PUSH
OE
7289
CO
01
70
5230
CALL
LINE
4130
PUSH
HL
72BC
01
5240
POP
OE
38
4140
LO
8*580
72B0
El
5250
POP
HL
81
70
4159
CALL
LINE
72BE
Cl
5260
POP
BC
C3
4160
LO
A* • C•
PROMPT FOR
728F
10
08
5270
DJNZ
NEX 303
IF PA6IN8 COUNTER
74
79
4170
CALL
OUEST
DESTINATION
72C1
5280
•
IS 0* PA6E IS FULL
46
04
4180
CALL
NUMIN
ADDRESS
72C1
CO
A8
01
5290
CALL
KEYBD
BAIT FOR KEYPRESS
4100
LO
0* A
72C4
CO
E6
00
5300
CALL
ERASE
46
04
4200
CALL
NUMIN
72C7
06
0F
5310
LO
B»150
RELOAD PAGING COUNTER
4210
LD
E » A
72C9
C5
5320
NEX 30 3
PUSH
BC
1 SAVE ON STACK
4220
POP
BC
POP BLOCK SIZE
72CA
18
C7
S330
JR
NEX00
4230
POP
ML
< START ADOR
72CC
5340
•
4240
•
72CC
5350
• BRAP
-UP
4250
• MOVE
THE BLOCK
72CC
5360
•
4269
•
72CC
Cl
53 70
ENOALL
POP
BC
BERE ANY MISMATCHES
B0
4270
LOIR
72C0
CB
41
5380
BIT
0*C
FOUNO?
4280
•
72CF
20
• 6
5390
JR
NZ.FINI
4290
• PRINT END
ADDRESS
7201
21
97
73
5400
LD
HL * 1 DENT
YES* PRINT •SAME*
4300
• OF MOVED BLOCK
7204
CO
00
02
5411
CALL
TVE
4310
•
7207
CD
AE
70
5420
FINI
CALL
KEYPR
BAIT FOR KEYPRESS
38
4320
LO
8*560
7204
CA
56
72
5430
JP
Z *COMPAR
IF SPACE BAR.
81
70
4330
CALL
LINE
7200
5440
•
RERUN COMPARE
94
73
4340
LO
ML »ND
7200
C3
00
70
5450
JP
START
ELSE BACK TO MENU
00
02
4350
CALL
TVE
72E0
5460
•
4360
OEC
OE
72E0
5470
• ROUTINE TO PRINT ONE
4370
PUSH
OE
72E0
5480
• BYTE* BITH ASCII EQUIVALENT
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025 Page 25
311
7269
1269
7269 SC
7261 CD 46
7264 SO
7266 CD 46
7286 36 8D
7264 CO 79
7260 56
7266 CO 46
7261 36 BO
72F3 CD 79
7266 76
7267 6E 89
7269 39 94
7268 96 42
7260 18 94
7266 98 47
7361 18 96
7393 C6 89
7385 66 89
7387 39 92
7399 18 94
5490 • ANO CURRENT POINTER
5588 •
5519 PRINT
5629
5539
5549
5559
5569
5570
5580
5580
5600
5610
5620
5639
$640
5650
5660
5670
5680 ASCI I
5690
5700
5710
001
LD E*H
CALL NUMOUT
LO E»L
CALL NUNOUT
LD A#*
CALL TV
LO E»(HL)
CALL NUNOUT
LO A * •
CALL TV
LO A »(ML )
CP 89H
NC»DO I
B *9A2H
ASCI I
B»0A7H
NEX2T
80 M
80H
NC*NEX2T
NXT220
JR
LD
JR
LO
JR
ADO
CP
JR
JR
400RESS
735C
6100 FOR
OC
•FOR •
C6
C6
02
A0
PRINT 400RESS
7360
6119
OB
0
00
7361
6129 STUNG
OC
•STRING 1
03
04
02
C9 CE
C7
7367
6130
OB
0
PRINT BYTE IN
00
HEX OR OCTAL
7368
6149 NON
DC
•NONE*
CE
CF
CE
CS
736C
6150
06
0
00
IS IT ASCI 1 KITH
7360
6160 TO
OC
•TO C -
0'
HI OH BIT ON?
04
CF
49
C3 40
NO* PRINT ■
AO
A0
C4
7375
6170
OB
0
YES* PRINT •
00
SET HI6H BIT
7376
6190 UTIL
08
06 FH
NON IS IT A
7377
6190
OB
240
PRINTABLE CHAR?
19
NO* PRINT SPACE
7378
6290
DC
•TVC-64
•jtilit
7306 6E 66
5720 NEX2T CP
0FFH
YESl IS IT RUB?
04
06
C3
40
B6
7300
5730 •
(RU80UT MOULD
84
40
05
04
C9
7300
5740 •
CLEAR SCREEN)
CC
C9
04
C»
C5
7300 20 08
7306 CO 6F
7312 CD 66
7315 19 09
7317 65
7318 78
7319 CO 79
711C 01
7310 CO 79
7320 00 04
7322 CO 81
7325 C9
7126
7326
7326
7326
7326 3E C8
JR NZ#NEX45
NXT220 CALL SPACE
CALL SPACE
JR I NO
PUSH A6
LO A* B
CALL TV
POP AF
CALL TV
LO B»4
CALL LINE
RET
5750
6760
5770
5780
5790 NEX45
58 0 9
5610
6620
58 30
5840 INO
5650
5860
5070
5800
5990
5990 •
5919 HEXNOO LO
NO* YOU CAN PRINT IT
PRINT • OR '
PRINT BYTE IN ASCII
• ROUTINE TO SET
• HEX NOOE
SEE NOTE #3
03
73B8
65
7399
B8
C9
7302
3C
7393
00
7394
C4
7396
98
7397
A9
40
D4
CO
CF
6210
6220
C 6 CE
02
6230
6240
6250 NO
6260
OB
DC
OB
OB
OC
DB
6270 IDENT OC
CO C5
1010
•0 40NITOH•
600
0
• 0 ?'
0
• S4NE'
7328
32 47
01
592»
LO
(0147H)*A
739C
6280
06
0
732B
C3 08
70
5930
JP
START2
00
73 2 E
5940 •
7390
6290 •
732E
5950 • TEXT
FOR
7390
6300 • INPUT BUFFER
732£
5960 • BANNERS
7390
6310 •
732E
5978 •
7390
6320
OS
00
732E
5980 MON
OC
•MONITOR •
73A6
6330 INSU6
OS
1
CO
C6
CE
C9 04
CF
02
NO ERRORS FOUND
7335
5990
OB
0
00
FILE :
3000
67E8
7336
6000 SRCH
OC
•SEARCH*
READY
03
C5
Cl
02 C3
LTA8L
C8
AB
7353
ASCII
7303
BAX *JP
7103
BCZERO
718F
733C
6010
DB
0
61 10
7136
CMPR
7330
COMPAR
7256
001
7266
00
EN04LL
72CC
ENDPUT
7163
ERASE
00E6
FIN
71F3
7330
6020 CMPR
OC
•COMPARE*
61 N 1
7207
FINISH
04A9
FOR
735C
FOUND
72A0
C3
C6
CO
00 Cl
BE TAB
7087
603
71C1
HEX
7153
HEXMOD
7326
02
CS
HX
734 A
I06NT
7397
IMMEO
7062
INBU6
73A5
7344
6930
Ob
0
IND
7320
INPUT
706 C
INPUT0
7040
KEY80
0148
00
KEY PR
70AE
LINE
7081
LOAD
7159
LOOK
7280
7345
6940 NV
OC
•MOVE •
L00K2
7183
NASH
716C
MON
7326
NONTR
0500
CO
C6
06
Cb
MOVE
7160
MV
7345
NO
7394
NEX00
7293
7349
60 50
08
0
NEX2T
7309
NEX 303
72C9
NEX45
7317
NEX T 5
7158
00
OC
•HEX MODC’
NEXTb
7179
NEXT?
7196
NEXTB
7102
NON
7368
7344
6060 MX
NONE
7160
NOSKIP
7188
NOTLIT
7112
NTVILO
7155
C8
C6
08
40 CD
NUMBER
7123
NUMIN
0 4 46
NUMOUT
0246
NUNS
7047
C6
C4
CS
NX T 2 2 0
7306
ON 60
7240
PRINT
72E9
PR INT2
718E
7352
6070
08
0
OUEST
7074
QUEST 1
7077
ROTATE
71A4
SEARCH
7084
00
setlit
711C
SHORT
7166
SPACE
7066
SPC
7074
7353
6080 AB
OC
• A - 8 •
SRCH
7336
START
7000
START2
7008
STRN6
7361
40
Cl
40
AO A0
table
7065
TEST
7144
TO
7360
TV
7879
C2
40
40
TVE
0200
UTIL
7376
736B
6090
DB
0
file
3000
6768
00
READY
PILOT ON NORTHSTAR DISK
Dear Dr. Dobb: Received: 78 June 9
Through the kind cooperation of the author, Dr. John
Starkweather, the source code for 8080 PILOT which you
published in your Journal last year is now available in machine
readable form from the North Star Software Exchange.
Anyone interested may order diskette NSSE5 from:
North Star Software Exchange
2547 Ninth Street
Berkeley, CA 94710
The price is $9.50 including the cost of the diskette. The
diskette also includes a remarks file and an executable file con¬
taining a preliminary version of PILOT modified to run with
the North Star DOS. This file also includes the standard
PILOT demonstration program.
Sincerely,
Thos Sumner
Page 26
312
THE 6502 PROGRAM EXCHANGE
News Release Received: 78 June 13
Apple II users can now run an extended version of the high-
level language FOCAL (DEC trademark). FCL65E, as it is
called, is available on an Apple II format cassette ($25) and
occupies 1000H-2665H in memory. A Mini-Manual ($6) pro¬
vides I/O information and descriptions of FCL65E’s com¬
mands. The FCL65E User’s Manual ($12) contains 104 pages
of programming examples to help you exploit the power of
the language. The complete source listing in cross-assembly
form ($35) will enable the enthusiast to customize FCL65E
for his particular applications. KIM and TIM cross-assemblies,
paper tapes, and KIM Hypertape cassettes are also available.
For further details and information on other available 6502
software, send $1.00 to The 6502 Program Exchange, 2920
Moana, Reno, NV 89509.
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
A Shorter Printer Driver for
PolyMorphic's BASIC
BY RICHARD B. EMERSON
158 E. Butler Ave.
Ambler, PA 19002 COPYRIGHT© 1978
I am the proud owner of a PolyMorphic Systems Poly 88
with an 8080A CPU, Video Terminal Interface (VTI), 20K of
memory from various vendors (Godbout, IMS, and IMSAI in
order of preference), A Poly Cassette Interface, and a Poly
Printer Interface. It is this last item that led me to write this
article.
Sooner or later every computer owner wants a permanent
copy of his triumphs (the very non-permanent CRT is fine for
the less memorable events!) and at the same time it becomes
painfully clear that a hard copy device is not cheap. Most
printers that warrant any serious consideration are priced at or
above the cost of a CPU and cabinet. I am fortunate enough to
have access to a TI-745 portable terminal. This fact removed
the first obstacle to getting a printer running. The second
problem is the matter of finding the electronics to drive the
printer. Unfortunately, most printers lack the good grace to al¬
low you to hook your printer up to your particular bus, be it
S-100, SWTPC, Benton Harbor, or Greyhound. This is where
the manufacturers of parallel to serial and serial to parallel
interfaces come in. They make boards that put the right signals
in the right places so that your printer can be “heard”. My
first thought was to buy a printer interface from PolyMorphic
but a shortage caused by problems with the printed circuit
manufacturer meant that the interfaces were as scarce as
programs that run perfectly the first time. I decided to look
elsewhere.
I didn’t have too much success finding replacements be¬
cause the Poly 88 CPU clock runs about 9% slower than most
8080 systems. This is so that the VTI can use the system clock
to generate the needed sync signals for an essentially flicker
free display. When I tried to use a Franklin Electric 3S+P I/O
board the baud rates came out all wrong even at rates as low as
110 baud. The card is capable of running as fast as 9600 baud
and every rate was off by a significant amount. If you do have
a need for three serial ports and if you have a 2 MHz clock, the
Franklin Electric board at $150 is a bargain that is hard to
beat. Actually, even had the board been compatible with my
Poly 88, I would still have been faced with the problem of
software. Poly’s printer interface uses a USART with connec¬
tions to ports 0 and 1. Because the cassette interface also uses
the same ports, just changing the IN and OUT instructions to
new ports would not have the desired results even if one as¬
sumes that just changing ports would work at all. This is prob¬
lem number three; without the software to drive the printer
interface, all you will have is an impressive looking drain on
your budget.
While standing around waiting for my printer interface kit
to be delivered I reviewed what I needed to drive my printer.
The assembler that I had just bought (PolyMorphic’s Assem¬
bler version G02) has a driver already written into it. My
BASIC doesn’t have a driver in it but Poly does supply an
auxiliary program that will drive a printer connected to their
printer interface card. It seemed, then, that I was spared
having to write anything to make my printer work.
My waiting was rewarded by a phone call from the good
folks at Personal Computer Corporation in Fraser, PA. My
interface had arrived! Before leaving Personal Computer I de¬
cided to check the parts list against the parts that were actual¬
ly in the box as there weren’t too many parts to check. It was
a good thing that I checked because ALL of the parts for
driving a current loop device, such as a Teletype, were missing.
Personal Computer offered to replace the parts with some
from another kit in the shipment, but the parts were missing
from that kit, too! In my case the loss is annoying more than
anything else, but for $65 I think that PolyMorphic could have
done better.
The kit went together with only one or two bits of excite¬
ment. The first thrill was finding out that what I thought to be
a 1N5252 diode wasn’t. Thinking nasty thoughts about kit
packers, I double-checked the manual to see if an alternate
part number was listed somewhere. Sure enough, four pages
later, buried in the instructions was the other number,
1N5254A. The second thrill was finding that the resistors R2
and R5 were not mentioned because they seem to have been
dropped from the design (I like to see sequential numbers
when it comes to parts call-outs.). A note saying that they had
been dropped would have saved me much page flipping. By
following the rather crude sketches on page nine of the manu¬
al, I set up the jumpers needed to test the card. The next step
was a smoke test so I pulled all of the cards in the mainframe
except the CPU which is where the interface is connected. This
may seem a bit extreme, pulling all of the cards out, but it is
cheaper than having a short or wiring error smoke more than
just the new card.
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 27
313
Having passed the smoke test properly, I ran the test pro¬
gram which echos data at 9600 baud. This ran the first time
off, a very pleasant surprise. All that remained was to hook up
the TI-745 and try it out. The owner’s manual from Texas
Instruments told me what pins did what on the terminal’s
connector and so it was easy to connect up a cable. Well, it
was almost easy, the control leads took a little tinkering. The
TI-745 requires that the Data Carrier Detect (DCD) line be
pulled high before the terminal will run. By connecting the
DCD line to the terminal’s own Data Terminal Ready (DTR)
line, the terminal tricks itself into running. I did not want to
put the jumper between the DCD line and the DTR line on the
TI-745’s connector so I borrowed pins 5 and 6 of J1 on the
interface card. Ordinarily, pin 8, the DCD line, does not ap¬
pear on the jumper block, J1. However, by tying the pin 8 side
of the CF jumper near J2 to the pin 5 side of the CC jumper,
it is possible to make the DCD line appear on J1. All that re¬
mains is to tie pins 5 and 6 together at J1 and to remove the
jumper that PolyMorphic recommends go between pins 9 and
10. While the steps discussed above are fine for a TI-745,
other printers may need different connections. The printer
interface manual suggests connections for Teletypes, Dec-
writers (available from Heathkit at a fair price), and Hytypers.
My first attempt to use the printer with the assembler was a
great success. I was also able to use BPRINT, the BASIC
printer driver, to list off programs written in BASIC and also
to copy the program’s output from the screen. I soon found
that BPRINT has one major flaw. It takes up over 500 bytes,
and, since I’m cheap, I’d rather put program code in those
bytes than a space-eating buffer. The majority of the space is
consumed by a 256 byte circular buffer while the code resides
in the remaining space. The obvious question was, could the
buffer be cut down without hurting performance and the
answer is yes (Why else would I write this article?).
The accompanying listing of BPRINT retains the essential
features of PolyMorphic’s BPRINT. It switches on the printer
with CTRL/Q and the keyboard is switched on with CTRL/R.
CTRL/S and CTRL/T turn off the printer and keyboard
respectively. The restart address is not the same as the one that
Poly specifies. Use 4A8D instead. The baud rate table on page
five of Poly’s writeup for BPRINT still applies for the most
part, the only change is that the constant for the baud rate is
now at 4A42. If you want to change the number of pad char¬
acters from the current value of 10, put the new value into
4A7C but be sure that it is not less than 1 or evil things will
happen. Sharp-eyed readers will note that the buffer extends
from 4B0F down to 4B00 while ERRMSG extends from
4ACD up to 4B03. This is not a real problem because either
BPRINT loads, in which case ERRMSG is excess baggage, or
BPRINT doesn’t load, in which case the buffer isn’t likely to
be needed. If you are still bothered by this, all that is needed
is to shorten ERRMSG and be sure to end it with a zero byte.
For those who understand circular buffers, that’s it. There is
only one final caution. Sometimes the printer will start print¬
ing one character over and over when restarting with the
CTRL/Q. Don’t panic, just type another CTRL/Q and hit
return. The USART is being asked to drive two devices and it
appears that noise on the CPU card can sometimes cause the
USART to start sending nonsense. In the writeup that comes
with PolyMorphic’s BPRINT, they insist that you must restart
BASIC through the point labeled START (4A8D on this ver¬
sion). In fact it appears that 99% of the time you can restart
through 2003 as always. This has been tried in both versions
of BPRINT with good success. The only “gotcha” seems to be
that WH1 (0C24) and SRA4 (0C16) must not be modified. It
is, in fact, possible to type CTRL/Q, CTRL/R, return, and
then record type-ins made after typing CTRL/Z. The screen’s
display of the registers and so on do not come through WH1 so
they are not printed, but any type-ins made will appear on the
screen as always and on the printer, too.
One thing needs to be made quite clear about circular or
ring buffers. The name describes only the concept; they aren’t
really circular. But it makes it easier to visualize how the
buffer functions. What happens is that a range of addresses is
selected such that the highest and lowest addresses seem to be
adjacent. The accompanying sketches show how this feat of
memory topology is possible. In this program, the lowest two
digits of the pointers’ addresses meet this requirement. If you
look at the lines after the labels WRITE and SEND you will
see that the L register is decremented and tested for zero. In
this case L will be restored to OF making 4B00 seem adjacent
to 4B0F. A buffer that is 256 bytes long would be restored to
FF automatically by the DCR L instruction. The HL register
pair may contain either BPP (Buffer Put Pointer) or BGP
(Buffer Get Pointer) but for the purposes of this discussion all
that matters is understanding why address 4B00 can be
thought of as being adjacent to 4B0F. Study the sketches of
how the pointers move. At the start of the program both BPP
and BGP point to the same place. As data comes in BPP moves
ahead of BGP, and BPP will continue to advance until it is
again equal to BGP and the buffer is full. Any time a character
is read from the buffer, BGP advances and it may continue to
advance until it is equal to BPP and the buffer is empty. In the
second example the buffer has started to fill with the string
“THE QUICK BROWN FOX”, however, the character “3”
is left over from something else that was in the buffer.
BPP is loading an “N” and BGP is getting a “T”. The one thing
that must not happen is to have the “get” pointer move ahead
of the “put” pointer. If this should happen you might wind up
getting back characters that haven’t been put in the buffer yet!
Actually old characters would come out but in any case the
results would not be valid.
The example of the buffer is one character away from being
full. Since BPP may not pass BGP or “wrap-around”, what can
be done? The easiest way out is to stop BASIC from producing
too many characters for the buffer. WAIT does this by making
sure that the interrupts have been enabled and then halting the
CPU. When the USART asks for the next character it generates
an interrupt, forcing the CPU to start running at routine TISR
(Terminal Interrupt Service Routine). There is a chance that
something else generated the interrupt (The console keyboard
and real-time clock both use interrupts and you may have
added devices that also generate interrupts).) so the first thing
that is done is to verify that the USART did, in fact, cause the
interrupt. If it did, READ or WRITE is executed, depending
on the USART’s status buffer, otherwise the CPU is sent off
through IORET, the monitor’s return point for all interrupt
service routines, to see what happened.
There you have it, circular buffers are in fact handy bits
of software that allow you to tie together a fast CPU and a
slow printer without resorting to magic incantations or lots of
expensive chips. As you can see, circular buffers are quite easy
to understand once you, ah, get a-round to it. ..
Page 28
314
Dr. Dobb's Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, CA 94025
Number 27
Number 27
CS
ill
2
o
d
_ C*
in
I s 3
o'
ui
u <J
u. -r
D
cQ
ul
£
C*
ui
_i
§ X
X X I
*- xl =t
X X
E2G
I
H x
•xi jj 21 X
x a
□ □ • X) Cl
^ MU -
-<LL
ix aJ
U-Z
■XuJ
>co
*-*r--
ix cr.
UJO
K- w
X
— □ LL CJ
•i
> h- x
a. co
six
x •=• uj
•X ■=■ o
</) OJ OJ
(/> </)
■I •!
Cm CO
x o <r i
c- > /> i
x> to x* :
I I CO
w w r-
Uj x- X
CU 'XI □
W I rl r
X -t •.
'*u - V o •:
a. aJ UJ l
'I 1 LlI X L
I 'X a. □ C
o
: x« x> X- x> •:•••':
x ♦ x
IX IX ^
: i uj ■ ix co
j *r u. w j j .
* Ul CO *t
CO
:• X _i X' x> ld
:■ 'X G8 G> IX
J UJ LU LiJ □
IX
• a. uJ •! ix
■X t
' *1 ■!
] — ix
: > •• to
■ i/J IX'
. uj • X
IIW'I
• — IX I
•! O
• O
. a
: i x c
< *- i- uj •:
x I
J □ X UJ '
■I 'I a _j
•- -X -I > t-
h- 1 - i- x •••:■
I X CO Z'
a □
LL X 1=1 H -X
U. I I- UJ
□ uj h I r
LL Ji-MO
-• </> > 'I _J
1 □ UJ —■ uJ J
« x > a. •!
' -i .=1
1 1 - _j
i x .
J X> X '!> A A A
□ UJ i
i— </> l.
□ " '
II
LL P H
•X* -< L
:• -x x ix .r i=i
X' X
□ □
ix ix
'I Cl ll h I j •;
ll r j x x x x h i- i i
□ “) M ”1 H "l £t IJ .
: J 3 J CO o .
■ ix a
. _j </> a
; •! x cl x
z -I
IX ixi
UJ XI
. h- z •-
□ X' X' LL
• □ CL LL LL Q
•I □ X
IXI l£r f—
■» CO CO
J M □
Z X z
w w ..
X' UJ Tf
H CL 'I •
uj o ll :
i— (s) :
Z U. C'J -t I U. X
• 'I
: 'X* Cl
j x
« CO OJ *t •=■ u.
:• o o o ix ixi
:• o o O rf rt
IXI LL 'I U. OJ
'T. .J. . 7 . ,7 17 .
’t rf rf rf
•I 'I
’t
r. ir«
-1 r - .1 Mi 1
1—1 Ll f - -t Q £
1=1 '=' 01' •=■ '£' a L
OJ UJ OJ CO CO LU 0
'_' '-'J '-'J 1=1 '.
t_. u. "j £' r-- OC' co 1=1 '=■ oj it.' r -
L"J M M M M M k-l M 111 UJ 111 UJ
■7 >7 >7' '7 -7 >7- '?■ '7- -7 '7 i7 >7 17 .
'I Cm (J
UJ UJ UJ
•7 <7 - '7 .
’t rt
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
315
•—i X I > uJ ul a. a.
□ □ I J j. CL IX X •
LL LL J 11 □ ij I- U ^ “ 1
t- t- r- . > x . . > =' ^ ,
Z' uJ t- D I I *•*■ X 7J
a. '£■ lL ul X uJ — 11 X i— i
LL r J LL —' > I
ll ii Z j G □ CU <£> X □
Lu ill □ I t— r- Z r- i
X u. Z tO aJ — Cl ,
X X > > UL ►- X >••0 h- r lu i
GDhhOZCQDni— UII
w w i— H - 3 — • a. i. i
•• •» •* •» •' LL LU * X 'I — <
LL I Cl LU I-
X LU
Z ii I CO
lu x -x •:
*— I uJ
i— _i ll
>■ X LL LU I
:< > Li z
LL * Zl—
1 - -I to x *— •
lu I uj □ □ lu • ■ ■:
• £• O > Z a. I I c
uj
C-> i/\ ll Z LL
LU — -« X
</f I 1=1 X
Cl '_' f— □ I
LU 0J OJ — — OJ XXX '
►— h- X H LU
Z t- h- Z X X
j i=i to to to to to a h- a x :
. Z Cl W M Cl M IJ U □ I- 1=1 .
X Z X
X h- 'll o
(-0 X Z' U) Z h
•i' i- ji a h-
X III ■£' to □ X □ _J X
J X X J J X □ Z X LO ID X
X X X' X X X X H-
: x n — _j x x x _i _i — _j x ►— — > x _i x x x
: >_• z x i x h- t- i x x i z — x □ x w x z z z x
• X -> _l to X to . I _J I I _J to li) "I UJ UJ J X □ ■ U M -I Z C
X
ax x
z □ □
Z X X
XX X
.. UJ LU
X X
_ ’f t
Q X N X
8 ~v X U‘ OJ >?•
ij. ft W o H rf If' I- O' X X
f r - r- a< X' oj X- o:« x< x co
X X X X X X X X X X X
rt rf »f rf rf rf rf rf rf rf rf
LU LU 1- LU
O ij X
CO H H UJ I UJ I^J CO I
X oj — •=• — X (J oj .
w uj i’ 't r - oj x i
iYi O'* O' o. O' O. |7-, |7. I
X X X X X X X X I
rtrf*ff»frt*frf
x x o x x x a - o ®
•t «t OJ *t *t ■=■ rf rf o CO
•i' X t-< *7' X If' X X U"|
' J> •=■ If' X' X' OJ X' X OJ •=•
1=1 OJ — OJ X OJ Oj x oj — OJ X 0*1
»-* •=• <_i OJ oj il CO CO OJ OJ CO OJ X CJ
X X »-« rf I'- X' X X — rf P- X X
O' O' X X X X X X X X X X X X
X X X X X X X X X X X X X X
’trfrfrfrf'frfrfrfrfrfrfrfrf
17' o .7 ' U* X
f •- CU’t a- X'
x x ■•_' x <_« a« co x« *7 .
rf «t •=• *r X' co u"i r . x> •
IT* OJ rf OJ Ll 07 ■
LU CU u • £> CO rf '*u h- I
M H UJ N <1 Q 07 07 •=• •=• CU 07 OJ I
X CU IX X I_j |*U O Sfl CU *t t r - •
LU Ll CU X' rf f - XX LU CU X' X LU '
X X '_' '_' O O O X 1=1 X L-i I
X X X X X X X X X X X X X '
rfrfrfrfrfrfrfrf rf rf rf rf rf •
^ © Cd .=' rf © |J,
X' OJ x OJ N ITJ rf
'*0 rf U- x © CO CO O
X' N X' I'- OJ IS- if' o
■=• oj x in x cr. — —
oj cu x r - x x ’t i*u
'7' UJ 00 o 00 «7J 07
rt x x cu r- x t
IT' a- X »-< If' X- X *-i
LU LU LU Ll Ll Ll Ll •=•
X X X X X X X X
't’tTfrfrfrrrtrf
- a ll
a
r > x
X x _i _i —
cl x _i «- a 3
I- X X Z f- r- r
G ft u ii Z •
. i uj m i i i uj i;
■ i it J j 2 Cl ' • l
i —' OX ul O Z' i
X UJ f iL h
' 0 »— to to lG to ►— .
.XJLUXUir-UlUJ.
< *-• lu x i- > to ll _i •:
I-* *Z* uJ to
ZZ Jr
-< □ x X z>
Z O Cl O aJ
i— » CL
x r- □ X I
X —' x Z 1 X uJ
UJ'Im X
D uj i j xx a
XI »t—
*- a z I- I to
X I— □ UJ ■=• x
X' tO Z tO rfr x
J • z z to
J X X •
: □ I c
» X 3 »- Z
:« n X
xxx z
J it J ' J X □
: □ a x x x
■ x xx
to h- x x x
: x x x z x
] x to x x x
•- *T |£| Zi »
t- X X H- X
» X X X ' ll
i i • i a to —
*- *— X
X' — 'Zi H UJ X J
X X X X X Z X
x X Ll X X X
X □ X XntfiH 1.0 x
*- CL to x X CL N Mil li X
'JDjHigMuZt.QE rj I 5 ►
J X u. u. LJ X Z X X “• z X '_' “!• to X l
XI XX
to to — XXX
? x im
* X X X • ' I ■ .X I
_ X x z
•—< »—< h- X xxx
U. It M J J M (: a. i X x i :> X x a. xx
p o X I _|I Z X X I— z X X t- Z X X
LL x X t-.i to Z □ I x to X tO ~f X O Q
UJ UJ (J
i X X
XXI h-
] □ X I- - UJ
> £L X X UJ CL
to a. ll z x
— *t CU LU □
X <x o to X
•►XX
LU 'Ll —• U‘| CO i.
u. r - xxx'
: x x x -r X x i x
X OJ o
•=• t •=• rt
' -V X X X
i - x x
>;u cu x • £■ ■=• .
X X X x
’t t rj- rt
x in r - r -- — cu
•=• co ixi cu •=• r .
I *-« cu CU X co CO
1 X CU OJ 0J 07 1=1
) i7- i_i x OJ •£> 07 '7- '_' X *7J rf >.£/ it. i
V 'v! % t t t ** * *»■ u*. uo ijo i
: '5 i 2 2 2 ' r ,r 'I * 'I 'I 'I X X '
oo
— X 07 X i7 -
X 0J X X O
cu o:* •.£■ i - co
r - r ■ r-. r. r-.
X X X X X
rt rf rf »f Tf
Page 30
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
Fast Cassette Interface
for the 6502
BY CARL MOSER
3239 Linda Drive
Winston-Salem, NC 27106
The February 1977 issue of Byte (page 82) contained an
interesting article on a minimum hardware cassette interface. I
have used this technique to develop a cassette I/O to record
and load on tape at over 1600 baud. Because I don’t unpack
bytes for recording, the effective data rate is over 160 bytes/
second. The accompanying software listing for 6502 systems
provides a record start sequence which requires at least ten 16
bytes followed with an OE byte to be inputted in sucession be¬
fore loading can commence. At the end of loading, two byte
checksum is used to detect errors. The hardware consists of a
direct connection from a one-bit output port to the micro¬
phone input and a non-inverting hysterisis circuit incorporat¬
ing an LM339 comparator as the playback electronics. Actual¬
ly, I’ve used a direct connection for the playback with success
but some cassette decks won’t work unless the comparator is
used. My General Electric and two Sanyo tape decks work
very well without the comparator but the Realistic deck won’t
operate at all without the comparator.
An interesting note is that some tape decks put the signal
on the barrel of the record and play jacks instead of on the in¬
ner tip. I’ve found that in my Realistic deck, the earphone out¬
put signal is on the barrel and the record input in on the inner
tip. With both the record and play leads inserted, this creates
an effective short.
To use this software, enter data in memory locations 0180-
0184 as follows:
0180 = LOAD/NO
0181 -0182 = Start Address
0183-0184 = End Address
The record routine will record from Start Address to End Ad¬
dress. LOAD/NO has no meaning to the record software.
The load routine will load from Start Address to End Ad¬
dress but store data in memory only if LOAD/NO does not
equal zero. When equal 00, LOAD/NO can be used for verify¬
ing and conditionally selecting modules on tape.
The load and record routines have callable entry points at
C/WRITE (3E00) and C/READ (3EA5), and non-caUable en¬
try points at LOAD.ENTRY (3F41) and RECORD.ENT
(3F52). If C/READ is called, the Z-bit of the PSR will be true
on return if no error was detected and false if errors occurred.
If execution is at the non-callable entry LOAD.ENTRY, a
break (via a BRK instruction) will be executed at end of load¬
ing and register A will indicate if the data was loaded correct¬
ly: R(A)=00 for good load, and EE for error.
To sum up, this has been a very reliable scheme and works
error-free with the cheapest tapes (even Concert tapes which
can be bought at many department stores at 3 for $ 1.00).
♦sv
Cassette z/o /Vardujare.
« O
C_> N
O
o rs
or co
ir
• o
o <1 «J
uj uj —
a o' >
^ n x
o o
O — CO UJ
s *— o
— o •—
UJ — UJ
uj cr cr ►—
►— o UJ
uj .. to
CO ►— UJ CO
to cr ►— o
•a o ►— o
o a uj
to o
to *—
5 . *“ <1 7
• I « o —
II UJ u*
a ice ►
a. uj uj uj o
►— o o •— UJ
r: • • — or
o cr —
v. s o
0.0 0
Z M UJ
— cr or zr
o o *— Z'
ii a a — o
II WHO
•» o o — —
o
o
tv o ^ cr ir «c
o o o o o o
V ♦*- U_ V
<3 UJ Z - >— <3
— > ►- => ^ a.
an >- o o o
<3 to x o o *— z
» x ►— * + o w 3 s i—
o z J a • rr cl o cr
II UJ 3 O- Z •- O Z« 7 <lO
II I O O >- — O — O »— Z
••OOU-tOTC<r •• •• _l to UJ
iSKiSR.issR5iS(S'Se;f;sp:isis.&sii.siS(sss
•-Mfneiir. (f^ao - so(\jn^musor<T'S r_ (\jcnTiin
«—«— *-«—*— ojojcsjrsjfvcu
f 5 ®S(SKK(S(SSISISIS<S)ISeJISISiSIS 3 S®ISIS®S
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 31
317
_j o cr
iu a o
O O Q. C
O \ l
<3 <J <J
1X0" <TO«J<3 x y iD 1/1
T O rr ►— _j I <j co o ^ ui 7 *—
a. —iocoo-O-i——d i <1 i/ia i- d i Q-
v ♦
to ♦ CO
to — tn in ts 7 in z
o: s ir ir (f uj cr uj
QO-OO-f^sO V.
O — OQO>— 00>—
«TX'<l<J70'«370
♦ CO* * UJ 7 * U. 7
uuju<iao«aoui/i
7770X^00X0 Ui ►— «
— x — _jO(T_jo<rcoa:
o o
is o o
IT O UJ
tsts.ssis.isK. ssssensssisis es
co<ris«-cvjw<iri(frv(roiis»-(\jn^irtc(>.
or® cncrcrCT'crcTfTCTcrrT s ss. s 5 ms <s
®®ISISS5i®ISI^ISS(Sr-«-r-^^^r-^
IS.KIS^I&KCt.KISIRrCSKiSiSS.ITlSK-S'SStSKlStS.PisisiS.ISIRlS'SSIS^^'E^IS.S^'rtRIS'SIC;
oc cr ps »* tj it t£ r- or ® s «— (v, co ^3 iru.'^cc<T l «Sf-c\jn« mu ^a'eis,r(v/o*tfltC'*-rrt' <- m m « in
•S ^ 1 * *“ * r ~~ r ~~ * ^ c\j <\j cvj i\j t\j <\j cvj fv cc c\j ro ro co 00 co m ro co n r > co tj ^ q ^ ^ m in in to 10 in
UJ UJ UJ UJ UJ
tc ic co m ic
is.T»es> a is 1 R o
s is. is S R lx. S u
CT-Ocroccocc S D (T- Qcr <1 <• «S is
tj <iis(rt£^«3(\j<(\j(ri£< o o t c
<s
ro u
tvj K:
o O
*- tc cvj r»
<r o cr o
o in o in is
« op < or tr
if N n r>- t or u no »—
usuucrsuocs
U rsu iTOSiPOISaS
U)Oiii<iu(r<U(Toic
'TS tr 'JL
SOU.'
<\J CC •s
«s or M
u is ro m an cr «3 cc uj *— co tr r>» ar cr cr
in ic if it tr ififiicifsNNN r»«.rxfs.
UJUIUJUJUJUJUJUJUJUJUJUJUJ uj uj uj
rororororororororororororo ro ro m
IS. (Vj
or at
UJ UJ
ro ro
t MTOUJ
an ar or or on
U< UJ UJ UJ UJ
ro ro ro ro ro
ul o nin n « o uj >" 'p *
occTcrcra'cr cr rr <j «i <3
U 1 U 1 ui UJ UJ UI UJ UJ UJ UJ UJ
ro ro ro ro ro ro ro ro ro ro ro
m r- rr
«j <1 <1
UJ U' UJ
— *— X
ar x o
* UJ CO
•a O Olfl
*— •— ►— UJ
nr tx »si
o o o —
►— Q- sj a. _j
X o
— UJ
»— o *—
7 X
<v x cr
ro *— m
7 UJ
7 7 X
O O CO
o o o _»
o cr o uj
* ui •* o
o N U V O
7 •• 7 Q. 7
X H- X O X
•— 00 — CO o m
** ♦ O * _l
or
< <1 rr u uj o
Q o l/l UJ ? U.
_j co —j o cr
co co
r x
o o
UJ UJ
X X
o o
* ♦
x x a. •—
• <r j «
CO \ o O
cr uj u v
3UI3XX
to > co cr o x
x «i x n ►—
O to O UJ — o
UJ Ul>- I I
o
o cr
co
<1 <3 <j ar <y —
o x o co _j cr
_j cl _i ~5 a. *
I CO CO ►— UJ *—
o *— 7 ►— X 7 a.
o — ox*— ac o o o
oujccocc-uj* cr o o •
♦ 7 0*CC70UJ0_J.
x o or • x • o 7 cvj • ^ (
o •• ►— cr o •• uj <1
1 co x or - o cr *— * *— — ►—(
.5C3ISCrilUJD!tDir<li
O O ** # ♦ N O U O * O I
crcr<T<j_jc_>crorrc_3Uj
■cocoo*—coocoujtnui7 •
' ") ■) _j co « i o rr o o r.
k 5 «s is IS
if v or cr s
(V (V, c\j c\i ro
IS S 5; IS IS
MSSISSRISISRRRISE'SSISISe:
oMn-oirifsa O'S'-MrowiotfKcr
ro ro ro ro ro ro ro no ro
SlSRlSISiSISISlS'S'SIS&iSRiSiSIS
is R s r is Ki-KssK)ira'sr-(v,si—(1 JS IS(S S ( SS( - 5 | SS | SK|ISS55SSKS5;SS
^ ^ *“ cv ro ir cc o-o-arcTiS)'—nocsjcorororo^jinif NccO'<T®»-MrO'o tcNcrs'-mro^inirN
”' ”~ SJSSISISSCSSSSSRSlSSISSSRSSSSS
is S 5 R T is R R I
; 5 IS R RR S S R R Rl R I
R IS R
o cr o
« is or
5 If tf •“ R S Q S O'
(\j O
O' if O 5
<1 ar cv o o
UJ UJ
ro ro
s cvj ro cc r- u. tn
<s o o u ua u.
(Vj If tr s R R
«j ar ar <1 cvj cvj cr
o 0^3
in cr if r on
<1 TJ «J (S l£
iucnn«ifuroQifis
> RuuRp-smuu.
IRirirXRRRRtfR
J(VJ< 0 )S(TMU.MOO
a < u uj
S R R R
UJ UJ UJ UJ
no in
cvj ro
UJ UJ
UJ ®ro I C
cm ro no ro
UJ UJ UJ UJ
ro ro ro ro
CP< CC OR
no ro ro ro 4
UJ UJ uj uj ui
ro ro ro ro ro
«— roxO’IQli.f-ttfOfl
■*i'<»'ff'«j*jT»^Jininininir
LU XI 111 UI 111 III It! III HI III III II.
rorororororororororororo
Page 32
318
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
e.
' ti st co x x
II «I « T II (*) f"
"> <r O UJ T UJ © II ||
i n <i m iuuj ♦ «so
5 UJ \ II fO IT 4 Q U . 1
C O- *_ O II II O « V
J II (/• 7 «— 7 X cr * X
•lOiluNtr + lHSm
• im\art-c;3 ii
- c. >•— — --Ol/'O
soooxx^traco
^ _J 2 ? U) ir * x u i
rr. o O rr «a x
+ O 4— + + +
2 • •* s >: >
or ►— *— tt *r
o — — o •/> o
n ir <"a. < u.
« « 3* « O «
o _j (_> uj <x r « w
_J O x 7 O vO O —
O IT O T J T J i
n. or
V. s
UJ o *•
X
<1 <1 a i/i
4- 0 7 4-
_J ■» X
♦ ♦ ♦ ♦
3 : r 2-2
rr o rr =>
(✓> cr tr tr
t y x y
a c o <_?
u.i ui uj uj
T X «S T T
O O T. O O
« • » « •
OOO « «J C3 <» to
_j _j o *- o o »— —
o o <j cr_/ <3 co ur
r uj c x i i a. cuj a- x a a. a
w 7 O IT 002 07 IT CT O © 2
“3 x 7 7
is. «- cr
■o<y a cr o x r~ i/'
'f IT UJ <■ li’ 111 r— u.
U 1 uj co cr uj co co x x co
co po ii lu co ii ii ro cv ||
II II >- CO || UJ «— II X 2
X >- o ii o or + *~ co cn
on j o « o o- * ii a.
O* UJ 7 C •- O (/> ►- <4
_j o cf O — i i/i u. ui j or u.
\ 7 •'^'v'V -4 UJOtJO
«ujujninai-uau. +
►— * roc — o — — o \ n o
ii uj x o x <j or 7 ii 7
n u y a ui __ i/i ■» n — nr uj
CS KR'S'S'-(Mi!ns,<riS(^-j;Kis*-fVjcn»JU)|£^(r(TK'“(Vnn4lS'SS?K'»'(«;iSSSK'rE-S! , ;»p:SKS
cc ^-or'T , sss'“(vj'»-nuiu'i'crcrcr(r(r(ra''r crcr('(T'rfTiT\i— (V' r '«LPu'^o - r’' •- <v ^ ip ^ i—
*— '-■-'-fMM(\j(\j(Vj(\J(\JfVjCoOJ(\|MM(V('.OJfVi<Vj(\f\){'j(\(V(\J^cr rr r r, f rc"rrr'Crcr, 4 ) « 4) vt «
ru rocvjC'j(\i<>jruc»i<Njt\jrsjcvtvjoJCvj<\jfvj<Njf\jcvjcvjfVi<\JC\jtNjcv<\j<\j«\j(\jcvjcocvj«vjfvjc\jc\j<\JCv,tvj<vjrvjc\j<vicvjOsicv<\j
xf j~ sr **
O O UJ O -c- O
or x i ix uj ’S jt r.
*- rv O O «» cvj <i x
u 5 (V| « It nr a. a
«- (V (\i cvj cvj x; <vj cv.
u X X X X X X X
CO CO co CO CO CO CO co
rv. cv © co co
O OPOO
j or 10 u“ <r t uj s
■Oif or o tr or if
cr w or «s o UJ is.
-o CO CO CO CO CO ro Tj
x x u u u u u u.
co 00 co co ro co co co
in t s •— u 1 tr os
< t U 1 X R
rR(ris«!«U.'an; cc «R «s «s
M O « S IJ Uj w <3 0 (VI K UJ U 1
c- « « or <r « t uj s
U.ILU.U.U.U.UU.U.
co ro ro co co (o <0 c»i ro
1 tr cj or r*«, uj (
1 UJ n- UJ UJ U co
j co u. uj co <3 uj 11 ;
11 ur co 1 , uj co ui (
•— UJ II CL CO H ►—
— co uj 2 11 o - v <
(C II 7 O O i£ T >
• UJOUc \ \ ■
0 4-.. sum o ►
ar — t—ocroo-
uja r 7 \ o uj-
t 'vj * o — t_J _j cr :
O 2 UJ CO CO *
• 4— _) *— O or o -r jr (
. 7 S 7 « <J OO
. rr> a. — uj uj uj uj t
•00 c <3 cr u a: »s t x :
-00 U S N S \ S U O (
i « _i • * o * o ** « * :
o uj ♦ co uj
uj rr ^ 2 x 2 x uj
►— o x a. riuru*-
»- O • 2 <X CC> co >-
x 7uii/'OicxuJxuj'r
\\\tru\u>o>\
a o a. o \ a uj *i uj «i o
<3 «3 — OOOXCOXCO<I
uj o <i 7 o o o uj
U* *— O 4—0 O »— © XI *— v/“ 4 — CO *
o rr x rrx o rr •— o or to rr co uj
• o * o ■* • o •* • o ui o uj *—
0 Q. 4 — 0 — >— a.4—oa.cjo.0 <j
^ n - v — rr — \ s c \ o •—
UJ 7 c 7 c CS X 7 « UJ7 T 7 QT ©
*y — it — * «• « — ■» rr — d. — a. tr
a ui u uj v >- o a uj
7 7 Z 7 00.027
O IT — X _J O T O ac
O •— 4- to
_l CO CO —1
>o- ►c<iro««'<«Mrfl'iuj'r«jfi(/)
.-COOUJI— toooxoi co _j 2 7 to _J 2 4 -
<5 3 _J I CO -)T_jQ._ia.~5Q.OT -30.00-
« <J (O I
_J Q 4— 1
a. _j cr »ni
or rr c- rr uj
co to UJ '0 7
-3 -3 x “J t
cr c ct o © cr uj o to
CO UJ CO CO UJ CO 7 UJ o
"3 mcr t to t
IS5SKSSSSRISS ® R •“ R R S IS.
or or CT'iSi' - (Xjco^Tiocr r^-ar nr IT s r- oj
if u' if if it if if tr if tc tr if if ic if 4- r» n-
R , "RKSIV®'SR I SIS' _ (VIRRISRS • _ (V 1 ' r 5jRf(\JCJISRl^SSRS'S l SISSISRRiS'S'lS , SS , Sir , S Rts-R® iS’S’S'*:
or nr rr s «— cvj rf'oific^-’^r-cciTR' rvi(\.'(V(\i(\j' r 'rfrfrc»jirtC'^x i TS'— (VjrfTjifitct^crCT'iS: <— Mm^ififp^cftT' r—cviCOyj
ifici£^r.N4>4-N.f.4.r«.N4.Nor®ii ixacrccorir‘r(r(rcrirarccir'J’'3''T9'<y'(riTa'ff'(j'iS‘S®isisissis(sisr-i-'-r-
*“ *" •“ •“ T-^ *— w— 1- r- r- *— •— r- f— ^^^^r-^^-^*-(^(\;r>J<\J(Vjt\jrVjC\jCNJ<VJ<\J<\jCM<M
T SI X If tCOTU-O- R N (*l 4j
»— © o u. o ® uj >s uj s uo ir
(Teste's- -9 s s cr ® s 9 9 s
OOUJQ <1 O cn O O « ff or (vj
•X ■S Cu 'X U *“ T- f\, |J_ 9 Mt r* X
u> or !S o or x o o x< o es u< o u_
sois<-KRif(ririsorir 5 is t it s or rr r
(M*rU.«(VJ(r< 9 <J 9 (VI X O D CM if O -X LC <3 tc
xx oc ~r
cv j x e>. o
e: >s cr uo
<vj o < or.
x rr. s- x on x X *—
cvj x cr ro es (V, X cs
•se; rr r ©<s.oc«s.
cv. X (Vi (\j x CVJ O co cc
O IJJ tSi (NJ ^ (C or *1 o U' R I\ 9
•O <1 T T XXXXX XOOO
lil Itl III 11 J 11 J 11 i 11 i 11 i 111 ui lii iii hi
CO CO CO CO CO CO CO CO CO cocococo
v « Q X s| tcor<rxox<s Cv. SJ c-<r<ixox
OOOOQOQQQOQQXXXi X X X X X' X
XXXXXXXXXXXXXXX XX'XXX'X
cococococococoromcorocorococo co co co co co co
XX XX
XX XX
CO CO CO CO
•— x a.
■s © © es
xx xx
CO CO CO CO
<3 o x (Vi in r» c_J o
©©©i-r- r-*-r-r-
X X X X X XXX X
co co co co ro co ro ro co
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 33
A BASIC Renumbering Program
BY JOHN B. TRENHOLME
120 Montair Ct.
Danville, CA 94526
(415) 820-0909
This program renumbers Microsoft BASIC programs. It has
been designed to have all its routines self-contained so that it
doesn’t depend on the BASIC interpreter for subroutines. This
makes it larger than it might be, but also means it will work
with a variety of interpreters rather than just one. The specific
version presented is for 3.1 8K cassette BASIC, but simple
changes (below) will adapt it to other versions.
The program allows you to renumber starting from a line
number in the middle of the program, rather than just from
the beginning. This is so you can identify logical blocks of pro¬
gram statements by giving them line numbers starting with (for
example) 1000, 2000, 3000, etc. Debugging is much easier
when this is done, and other people can read the listing with¬
out getting hopelessly lost.
Input to the program consists of three numbers in RAM:
1. The increment to be used between lines (stored at
0004H & 0005 H).
2. The new line number of the first line to be renum¬
bered (stored at 0006H & 0007H).
3. The old line number of the first line to be renumbered
(stored at 0039H & 003AH = 57 10 & 58 10 ).
These numbers are stored in low RAM postitions so that
BASIC can POKE them to the desired values. The first two are
in places that BASIC uses to store the addresses of internal
routines for the user. These addresses are never used by
BASIC. The third argument is stored in two NOP locations fol¬
lowing a RETurn in RST7. If interrupt is used via RST7, an¬
other location will have to be used.
The renumbering program takes 512 bytes. The version pre¬
sented here is for use with a SOL, so it is assembled in the SOL
scratch RAM starting at C900H. To put it elsewhere by hand,
just change all the C9’s that are the third byte of 3-byte in¬
structions to 3E if you want the program to start at 3E00 (or
whatever), and all the CA’s to 3F (or whatever). The first C9,
for example, is at C90E. The program uses two bytes of RAM
which are presently at C8FE and C8FF; so C8FE will have
to be changed to somewhere else. Except for these two bytes,
the whole thing can be in ROM.
The following short program will renumber BASIC from in¬
side itself. It is especially handy while writing a program, since
you can quickly make space for more lines if you inadvertent¬
ly leave something out. When done, you can move the first line
of the program up to 10000 or so and renumber the successive
blocks to higher multiples of 1000 (then hitting RETURN dur¬
ing input and typing more numbers probably won’t clobber
the program). Then just delete the lines containing the renum¬
bering stuff, and you’re set to go.
1 INPUT “Increment between lines”; I
2 J = INT(I/256): POKE 4,I-256*J: POKE 5,J
3 INPUT “New number of first renumbered line”; I
4 J = lNT(I/256): POKE 6,1-256*J: POKE 7,J
5 INPUT “Old number of first line to renumber”; I
6 J = INT(I/256): POKE 57,I-256*J: POKE 58,J
7 POKE 73,0: POKE 74,201: J = USR(J)
In the last line, 73 and 74 are the locations of the user-defined
function, which depends on the version of BASIC being used.
The 201 is the high byte of C900H in “split decimal” nota¬
tion, which is what BASIC uses when referring to memory lo¬
cations. Change 201 if you move the program. To reuse the
same increment you used last time, type GOTO 3 instead of
RUN. If you’ve added new lines between old ones and want to
clean things up, just use GOTO 7.
Be careful when using this program. No error checking is
done to insure that you don’t renumber the program in non¬
ascending order, allow the line numbers to get larger than
65535 so they will wrap around to 0, or otherwise screw
things up. The author, from painful experience, always keeps a
backup copy of the program before making changes.
The one check that is made is for non-existent line num¬
bers. If the program finds GOTO 300 and there is no line 300,
it makes up a line number which is one more than the line
number that would follow the last line and puts that in in¬
stead. For example if the increment between lines is 10 and
the last line number becomes 540 after renumbering, the
GOTO 300 becomes GOTO 551. This is easily picked out
when reading a listing, and avoids incorrect jumps if (as is of¬
ten the case) you start typing new lines in at 550.
In Microsoft BASIC, the program is stored in RAM as a
series of lines. Each line has a two-byte pointer at the begin¬
ning, which points to the next line. Then there are two bytes
containing the line number in lo-hi binary form. Then the text
of the line is written in ASCII, except that reserved words such
as FOR, GOTO, SIN, etc. are replaced by one-byte “tokens”
which have their high bit set to 1 (i.e., they are “negative”).
In some versions, tokens may have more than one byte. The
text of each line is ended by a 00 byte. The program as a
whole is ended by a 0000 pointer, so the end has three 00
bytes in a row (one for the line, two for the pointer). Because
the pointers (which are used for fast searches in GOTO’s and
GOSUB’s) are in absolute address form, the text can’t be
moved unless the pointers are reset; it would be better to use
one byte to specify the length of the line so the program
would be relocatable and shorter. This would limit line length
to 256 bytes, which should not be a problem.
The program works by moving the program text as a whole
up near the stack, which is presumably well above the end of
the program (if not, memory is almost full and disaster may
occur-you did keep a backup copy, didn’t you?). It then
starts reading the text of the program, looking for GOTO,
GOSUB, and THEN tokens (ELSE also in extended). When
a token is found, it then looks for numbers after the token
(leading blanks before the numbers are copied unchanged).
When a number is found, it is converted to binary and a new
number is created. Instead of making a table of old and new
numbers, the program makes up the new number by using the
Page 34
320
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
Old line numbers that are stored in the program text. It starts
at the first line to be renumbered, and counts from the first
new line number by the increment amount, stepping once for
each line encountered. When the line with the old line number
is found, it has the new line number. This new number is then
converted to ASCII and inserted into the program text. The
program looks for a comma after the line number; if one is
found, it assumes there is a series of line numbers (as in ON K
GOTO 10, 20, 30) and looks for another.
As the search and conversion occur, the new text is moved
back down in RAM, and the pointers are reset appropriately.
The moving up and down is necessary because the length of
the text may change as (for example) line 214 becomes line
10160 (life would be much easier if the line numbers were pre¬
converted to binary before text storage). After all the numbers
in the text are reset, the numbers at the beginnings of the lines
are set to their new values. A jump is then made to a section of
BASIC which resets the stack and zeroes out the variables
(since the renumbering has very probably clobbered them).
The stack is preset before the jump so that the RETurn from
this BASIC routine is to location 0000, which causes BASIC to
give its OK and wait for more input.
The one word of RAM used is the storage for a pointer to
the beginning of the first line of be renumbered during the
text change phase, and for the new line number storage when
the numbers at the front of the lines are being changed. The
only tricky part is the updating of this pointer when the line it
points to is moved back down in RAM.
The method of using the lines themselves to make up new
line numbers is slower than making up a table (see Steve
Wozniak’s recent article in DDJ no. 23 on renumbering in an
Apple), and in fact takes time proportional to the square of
the number of lines to be renumbered. However, the program
renumbers a 400 line program in about 7 seconds on a 2 MHz
8080 system, so speed should not be a problem except in ex¬
ceptional cases. The space saved means larger programs can be
renumbered, so the tradeoff between time and space goes to
space in this case.
Other versions of BASIC can be renumbered also, but a new
version of the program will be needed for each one (sorry
‘bout that). The things the program has to know are:
1. TTie location of the stack base pointer STACK. This
is set by BASIC’s initialization routine, after it knows
how much memory it can use. Look in this section of
the code to find where it is (or see the listing of NEW
below).
2. The location of the pointer TEXT to the beginning
of the BASIC text. This usually follows STACK in RAM.
The text usually begins at or near the beginning of the
initialization code, so you can look for locations con¬
taining this address (plus or minus).
3. The location of the pointer SCALR to the end of the
BASIC text and the beginning of scalar variable storage.
This usually follows TEXT in RAM.
4. The location NEW2 of the entry to the routine for
NEW which does everything except text removal. NEW
will set SCALR to equal TEXT to delete text, then erase
array variables and strings similarly, reset the stack, and
RETurn. This program has to jump in after the text re¬
moval phase. See the appendix below for more about
NEW.
5. The tokens for GOTO, GOSUB, THEN, and (if ex¬
tended) ELSE. These are most easily found by writing a
short program containing them and looking at the resul¬
ting text of the program (starting where TEXT points).
In this version, ELSE is not used, but room has been left
for testing it by testing twice for THEN (see after label
NONUM). This makes hand patching easy.
There are a number of useful subroutines buried in this pro¬
gram. Comparison of DE and HL is done by DEMHL. TSDIG
checks to see if a byte represents a numeric character (0-9) in
ASCII. ASCDE is a standard routine to convert an unsigned
ASCII number between 0 and 65535 to binary (without error
checking). And DEASC will convert an unsigned binary num¬
ber to ASCII in RAM in about 2000 machine cycles, with lead¬
ing zeroes suppressed (the heart of this routine is a modified
version of one found in an article by Tabb and Roginsky in
EDN for January 5, 1977, page 46).
I hope you have a lot of fun using this routine, modifying
it, and (hopefully) improving it. If you come up with some¬
thing nice (the needed addresses for other BASICs, faster or
shorter code, etc.) drop a note to good ol’ Dr. Dobb’s so the
rest of us can know about it.
Appendix
The NEW routine can be found by looking in the command
address table for any specific version of Microsoft BASIC. In
3.1 8K cassette, this starts at 0170H. The entries are in the
same order as the literal table of commands, which contains
the ASCII text of the commands, functions, etc. (the first or
last character of each reserved word will have its high bit on);
this starts at 0088H (3.1 8K cassette only!). Just count off
two bytes per routine until you come to the entry for NEW,
which will be the address in lo-hi order. Then look in that
location for the routine. In 3.1 8K cassette, NEW starts at
039DH and looks like this:
NEW
RNZ
QUIT IF SOMETHING FOLLOWS
NEWl
LHLD
TEXT
GET POINTER TO TEXT AREA
XR A
A
ZERO
MOV
M, A
L0 POINTER =0
I NX
H
MOV
M, A
HI POINTER =0
I NX
H
SHLD
SCALR
SET TEXT TOP
—
---THIS
IS WHERE
WE COME IN-
NEW2
LHLD
TEXT
POINT TO TEXT
DC X
H
NEW3
SHLD
NTEXT
POINTER TO NEXT TEXT
LHLD
MEMTP
TOP OF MEMORY
SHLD
STRNG
ZERO OUT STRINGS
CALL
RESTR
DO "RESTORE"
LHLD
SCALR
SHLD
ARRAY
ZERO OUT SCALARS
SHLD
ENDVR
ZERO OUT ARRAYS
NEW4
POP
B
RETURN ADDRESS
LHLD
STACK
SP HL
RESET STACK
LX I
H,SLOTS
RESET TEMPORARIES
SHLD
SLOTP
L X I
H, 0
RETURN ADDRESS =0
PUSH
H
SHLD
STEXT
TEXT IF STOPPED
LHLD
NTEXT
NEXT TEXT
XRA
A
STA
VARFL
FLAG FOR FOR, DIM, FN
PUSH
B
RESTORE RETURN ADDRESS
RET
ALL DONE
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 35
321
X
o
X
c_
UJ <-*
X O
or. o_
01
ix
Uai <r j i :
•* *“X * •*
X X CJ UJ O .
X X
o X
o
ci
o
^ x x x <r ?- x x
x — X H-« o
e: e: o e: e: ci e_ x 2
• * • < * ~X X O •-<
XOXCL J <tX' U -X'XU.’xCiOOX^''CU lj: ~
UJ
X
Q O H o O
r r o ^ h:
X
^ <t
X
* o
>X <C 01
£3Z7: LC *-H NJ :
: «£ ui a.
X ^ ^
I X <c o
XnI>X>XX
^ 2 CJ O 2 CJ CJ E.
M -3 X F._ £“ X -1
X
<c
I— 1
X X Cl - J
ci :> x 2> :> <x oixr>x 2 >xxcLOQ-C-oa-x
XC^OOXJsjX^OZ'OX-CIC^'. Oi-h OU1
x F- —. ? J O-j0.h-i?:.-hF_JoX-DX-301XX
ff
■X x
* * * X
e: x
CJ X 2 o X UJ
01 X > 01 LC
01 5T.
X
* ■» x n
o Xc
X XU
01
i X
in CD H- CO C7 S — CM tO ^ m U X CX C7, S —• CM tO -TinCJXCCj'. S— CMtO-^TinCJXCO J. S —« CM fO <3 lA CD CX 0'S- -(\j fO <3 A CJ X »’ <7>
in itua irwn cjcjcDCDtDCDiDCDcDvjxxxxxxxxxxa cx'CCcccccx. cxcococx o c- cc o o o o (7 a k o fa f3 c ^ s r. cs> s •
sss s Q S S r3CslOir3f.'OSI^r)n?llS!SC3Nl3!5firjSRnRQQr)iS*?RKK)S^)^NS'S''--------<--'
S S S S S ®Q SRP5SRK s S S i51"IR^G l SQSr'' “
* * * 3-
; — Cm io ■?: iT' <t)
£7
CJ
£7. £7
CJ CJ
<7
O
Q (7 <7 CT
SO o o
J<
O
o
to x
M X
Cl
in
(7. j- o s
ro in in <r
s
<3
O'- S Q
■«T
X rO
<r
r-1
rO
Nl
X
X
to CM
X
to to CO
01 to
in
Lxj tO
CO
C7. S
c
in to
X
to vc
<i
o —
— to r-
— <7.
<3 S
X
in c
_
n cl
vj cj in
in
r- CM
x o
CM
CM
CM
<t
X
CM O
X
CJ r-
X CJ
X
^ CM
<T
r~ cq
CJ
CJ CM
in
cm in
CM
CJ x
X CJ CJ to
X CJ
r~
O' o
o CJ
X
X CJ
m u? t— r-
X
(Ti <X
X o o
X
S
—
CJ
fO
fO
<T m
a
a cm
o o
s
s
s
s
— Cm tO
<r in
O- <l CSJ
o Q
X
— -«T
m
X O' CJ
Cl x
X
X X
I*.
S —<
CO to
in
in in
in
vj r-
CM CM CM CM
X
CM CM
CO CM CM
CM
fO
Kl
fO
to
to
fO tO
iO
to to to
to to
■*r
<r
<r
<T
■<T -5T
<T
■<5 <1
<3
<T
<T
■<T <3'
*3-
in in
m
in in in
in m
n
in m
m
co m
vj
VO CO
<o>
CJ CJ
CJ
CJ CJ
O' CT> CT>
<T>
(7> (7>
0)0)0^
O
<7.
<7
C7-
C7
a
<7 O
<7>
ooa^
C7>
c
a.
C7
O
O O'-
C71
O O'
C7
C C7
O'
<7 C7 .
O <
C7> CA
O'
O' C - O'
C7 <7
(7>
C <7
a
O' O'
(7
<7 £7
O'
<7. o
C7
<7. O
O CJ O CJ
CJ
O O
CJ CJ CJ
O
O
CJ
CJ
CJ
o
CJ) CJ
O
CJ CJ o
CJ o
CJ
CJ
CJ
o
O O
O
O CJ
CJ
CJ CJ
CJ
O CJ
o
CJ CJ
CJ
CJ CJ CJ
CJ CJ
CJ
CJ CJ
CJ
CJ CJ
O
CJ CJ
CJ
CJ o
CJ
CJ o
* *
* 01
* e:
* <x
* X
* O
* O
* X
* X
*
* o
* >—l
* 05
* <X
* X
*
* X
* X
* o
* UJ
* o
* X
* o
* *
* *
■# X •
* X 2
*
*
*
*
*
* o
* -3
*
* X
* x
O 01 *
> 2 X ■*
: <i *
: -J x *
J -JO *
: <c —< *
* j> #
x *
r oo *
: x 2
£7 ■
* F-
1 <£ X #
- X 01 *
O X *
i * I— *
* n: 2 X *
* CJ O <£ *
* X * ft *-H »-H *
-# X * X 01 O *
* X # >- 01 X *
* e; * x
' * o
* o
i *
* <vo
*
* 2
■# X •
* X ■
* * * *
X
01
*
M *
o *
X >- *
X Oj *
e. e: *
X ^ *
X o *
X o *
*
* * *
0J
+ 00
X X + X
-UH 7
^ <i. X C
CJ I— x «o
S C/1 X S
X
01
X
X
X 2
X x — X
K' g < X
CCK Sh
X D D D OX3XXJ
CJ (J Gl C? 0 C3 U u
X X X X c/1 X X X X
X
X
CO
OXXCMOOX2X
< x <r :-t h h ui u o 1
I— X o x o o x x
O t- 01 ^ * C OH X
X
X
E-
CJ 0.
O X
o
X 2
3
o
X
e:
x -*r
o o
oi
o >-
X X
o <r
Uj x
o
x x
o e:
x x
x
X
X
<0
e:
Q
2.
X
y £
o
X
o
X
D3
xxx
X
X
CO
X XX
7T
CJ
<7'
X
CJ
X
Cl
X to
X XX
s
tO
DC
<c
S X
XT
o
1
X X
<E E EX
X
O X
s
o
X
• X
►—1
X
»
CL - »
CJ •> X J>
2.
s
-s-
s
s
s
X c/1
XXX
X x Q
•
X
Ul o X
C/l0lX<a:QFg
Cl
o
X
X
o
X
CJ
X
X
a x
X Cl
X X
X
Cl XXX
X
X
X
X
CJ
xxx
►-H Ul X
01 X X
CJ X
s— t
O J> >
XXXXXKil/1
<i
CJ
<t
CJ
X
3
o x X
X X>X
X <c o
2S X
X
<go
ICJOQXn^D
1—*
X
X
X
o
X
x oi
X 0_I
X CJ X
X X
X
O ^ E-
XCldEToiOIX
X
X
X
X
X
3
X
X
<r r
>
X
X
—•
X
—■*
X
X X
o
X
•«-
3
O Cl
t—l
Ul ^
e:
X
X
X
O
X
>
*
2
o
*
X
* X
*
IZ
—• cm to -«t incor^ cc cr, s —• cm *o <r in ^ h K 1 (?i s —- cm k> -^r in cj x do q — cm ki in ^h cg c7 s — cm to ^ in 'C h do C7 s — cm to ^
rjMQRQfisiOK — — — — — — — — — — cvjCMC0C\)(XCvJCM(\iC^(MfO'O'OfOfOfO'OK)rOro < 7' < T < T<r<ro'<T<r<r- | 7ininininin
SddRrniQnsriSSUSNQQilQSS'lS'^Sl'lSQPvSlSQQNSQSQSQSIQSSSlS'SlSQISSQ
GfirjilC5J3P?OOSOQQRClSSKKilRGKlCSnQGlSJOlSS(5r5(Sf5!lGSfOKKir\!PilSRP5K)KlKlRr3POr2
CM s co cr.
S S S (J
X
X
CO
s
<7. <7>
O O
o
s
s
ts
OSS
s s s
s s s
css
s s o
OSS
s s o
s s o
s s s
SOS
s s s
s s s
s s s s s
S S O Q S
S S Q S S
o o s s o
s
s
to
S
s
in
X
s
s
<T
■sT
X
<T
in
s
c
O'
—
m
<t
in
Q
_
S
—
£7
Q
■q-
c
00
CD
X
00
Q
CM
m
s
CM
X
CM
X
CM
X
CJ
Q
X
CM
tO
■»T
CM
s
CM
X
s
CJ
CJ
CJ
s
s
s
s
s
s
s
s
s
s
s
s
s
X
s
s
to
X
X
X
CJ
X
s — —
•«r
in
CJ
X
CO
CJ
Q
X
<3-
s
s
s
s
s
s
s
s
s
s
s
s
s
X
s
s
s
s
s
S
s
s
S
—. _
- _
_
_
—•
CM
CM
s
s
s
s
s
s
s
s
s
s
s
s
s
X
£7
O'
£7
£7
£7
O'
<7
£7
£7
O' O' O'
£7
O'
£7
£7
C7
£7
£7
£7
O'
£7
£7
K
s
s
s
s
s
CJ
CJ
CJ
CJ
CJ
CJ
CJ
CJ
CJ
CJ
CJ O CJ
CJ
CJ
O
CJ
o
CJ
CJ
o
CJ
CJ
CJ
322
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
UJ
2
cm m —
X X X X
x-sr. o
' -J U W
3 CD <£ _J X
; UJ CUJ • ►
I ^ X Q O CD :
cd
UJ Ci • <X is
- - C5--
:_JXXXQX* WQD
El“ CD «
UJ - O I
CJ X X <C • *-1 <
— X —
O El 3
-J UJ UJ
O Q •i'
HEO
o •• •
x x o <x x
—> X _J X >- _J X o
JQ.H J>>a. 1> <X <£ M X X X X -H CJ I— ►-< X W>r>OOQO^H>HHQX"XX:
CO»-i<rQOO OX ^ ^ X 2 2 2 El X X CJ X El X <t X<I0^)00<I<t<t<lX0^><I.0 O 2 I
i(_>xxu^^xE:o“3t^ c T-'»-'^) <T o x o o x xcjxxE-EqoooldEieiqxxx.-.:
5 O *-. Q
X <t o X
J (_) X —J
X o
CD X J> > X
x x o o 2
X E M
uj o »— x cd n m ox x _j h-
<3 ^ CD CD a <t OO 2 CD O 3 3 x
UJ CD CD*-* CO UJUJUJ
* * h- -#*#(—• * * # C Q * * 2 2 2
C\]fO^^^r^Cfia>o--CsJ*O' <T ‘ rv '^ r ^‘ CtJ ^SJ~"CVJ^-«T»rv'Dr“Xc7NCi--«0J»O<T»r*V£>r^C30^Sl--C0'O^J‘‘^^ >r ^CCa'S5 — Csl»O- , TiA'^r'C0<^«S3—■• CM *0 *0
COCCCOK)COCOCCCO(7\^^^a>^^£A(7'^SSSC3®C3SQCJC3 — — — — CMCMCMCMCMC>JCMCMCMCM»0'OrOrO»OtOrO*0*OrO - «r^''«T , *r*T-«T
— — — — — — — — — — CMCMCMCvlOOCMCMCMCMCMCMCMCMOJCvlCMCMCMCMCMOOCMCMCMCMCMCMCMCMCMOOCM CO CMCMCMCMCOCMCMCMCMCMOOCMCM
SSQSSQSSOSQQSISQSONSlSQSiSElQSOISSQiOfSQS'SSlOlSSCaiSSCaSSSSQSQISQSnsnSQSSISQSS
*r»iD Q — Qq-«T— UJUJ<tCVj^“0sjK)rO»O UJ CO UJU Oi -DCO^CW^O'^^WJu.^C^a; —*0UJUJ<I*0 <OCJO<Cin<UJ^rO
UJ O CJ UJ CJ ^ <TUJMi.L)®ffiUS(MU X Q U. rO CJ — OOXCDVDcMCsJ —• OJ D >T> — — UJ UJ (\] r- U. (J U CVJUQCJUJCM^C' CO
r^coa'(7iOQQ(S-wio<r w ^<couJii. s^ p O'0^in'^coc7'<<r<t<iQP3-WfO -«t *rv cd t- cc ctcQUJU.ks-w^ rv <i< <rcQe5-<nACO^<r
UUOUUUUDDDQOQQDQDQUJUJUlWUJUJUJUJUJUJliJUJUlWU.lt.lj.li.li.lj.li.U.U.lx.li.li.li.li.U.SSSQSSSSRQ-----*- 1 -
O'OsOsOsOO'OsOsOsOsOsOsO^OsO'OiOsOsO Os O' Os Os O' OsOsOsOsOsOsOsO, OsOsO" O' OsO OOsOsO, OsOsO^OsOs<L<X.<Z<Z<X.<L<X. <Z<Z.<Z<Z<X.<X.<X.<L<X.<X.
OOCJCJCJCJOCJCJOCJCJOCJOOCJOCJCJOOOOOCJOCJCJCJOCJOOCJCJCJOCJOCJCJOCJCJCJOOCJOOOOOCJOCJOCJCJCJCJCJCJ
o*
H
CD
X
CD CD
CD
<1 X
X
H- X
X *-*
X
CD X
X
<r i— 1
1—
X 2
H K CD
o
IH
XUi •—
CD
t- o
X 2 X
X X
1— 1—■
X
CD *
X
*—*
X •
A O CD
x •
1 X
1—
2
1—•
X S> ^
2
X X o
CJ
CD *-*
El X X
•> O X X •>
e: x
El Q X X O O X
1 uj xxx c
2 o ED E 2
x- t ei *-. eh^iwduj
>•> •> - X •• O 2 O 2 X
<txxx<cxxx<rx miccjo jh,
) > r> — x
X > X >
£i5£
X O X
x CD -J —1 NJ '
C X) x <C 2 x
X 0-IOTJ
x x <r
' 2 2 x M
I -• *-« C -3
^><IXX>5xX>5xXX^*-h m m
0H-Z2p^220H*X220XMX M X I
J.WHHLoTHHrc/ihHHEuTo “30'
IWWSt El
■ JUJ ?cc
UJ h- X) X X x c
UJ CD
J 2 o
i M CO
1 -J« X
IhN <t X X >
X 2 I- 2 2 o
O -J X * CD EI
mu E>-U)
El *-* ZD X Q
• x> a 2 <t o
2 CD O 2 CD
• JH2h<
X
XNCUHc
O ~D CJ “D X O
X
>
, ^ - CvlfO
• oo oj cm cm
<3 iTN CD r~- CO ^ Q
cm oo oo oo cm cm *o
—• X *0 -«T >T\ VD I
rO rO *0 rO *0 *0 I
| *0 *A CD
•«T -ST -<T
sr- < T^iAin»r*inir*inin*n»r»ir\cDCDCDcD cdcdc
I COh- 00 OiQ —
r- r- r- r~ to do
: rs OS>OOOOS)S)S><S)SG2
M53QSQC3Q8QISSQSQC58BQ S IS (
Si s s s si q
CO CTi CO
uuuu
O- Os O,
CJ CJ CJ
CM <1 Q ^ -(O
X X «T <T CJ x
fO-HfO 8 - ^ COCM - - 'OSOIXCM'O'O^CUCM'O'OXCM'O^XCM rOK)XX<rX<CX<I XX
xr--xf'^Qcjxcjoxf'~xr'“Xr-c3®xxcjc''‘®sjxf'~c3«s>c\jt-is ocMf"-Uou.oU_o x o
Os Os Os Os
CJ CJ CJ CJ
si *r* r o — <£
X X X <c X
X*0*0XX<tQc Q
SSCMf'kuUQ CJ
vm vm - - '-'J ^ RCM' S - u- 0 “- Ul*- U u-CJ CJSCMr-Li-UUQ CJ
<1 Q 8 — C\'>r'^COWCCJr^CO(7i<iCOUU.CM^CCcr. <xm(jDXli.8-<TinM9r^OC(7n3;XCjDXXU.®-fOWCOQ]OESCM^ir\incflr^COOaIlX'-«<r<r
^<Dt^f^ r -^r^i^ r ^ r -r^f--r'r'r-C' r --xxxxxKxxD 0 cccAC^<7^<7ic^c^cA<7'C^(7.c^c^cr5(^(7i<i<r<x<x<i:<x;<rxxxmxxmmmxmmooo
0< O O O'' O Os O OO O'OsOsOsOs O'* O'OsO'O' O' O', O, OsO'O'OOsOsOsOsO'OsOsOOsOsOsOsOsO^OsOsOO'O^OsOsOsOsO'O'OO'CXO'O'OsOsO'OsOsOsOOs
CJUOUUUUUOOUOOUOOOUCJOOUUUUUOUaOUUUOUOOOOUUUOOUULKJUUOOUOUUUOUUOUOL)
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 37
>-
OJ
r- -<T — rO CO vCi VCCC X
m —
X
X
CO <S <Z rO «0 CD <S —* X
<X
X
-J
x
X
o
CD G s c <r c Q C «j
CO <s
<r
c
-J
o
=*
{—
1—4
L) S ® G D O C?G O
s s
o
f:
X
X
1 —
2
03
S f—
—i
o
X
t—.
c
1 — x
+
o
o
<t
o
2
{—
o
CD
(—• X
UJ
1 —
03
h-
1—1
i—i
2
X
X
2 <t - 2 ) 1 — CC XI—
X
x <r —i
<1
CD
2
X
0 J
od
X
X
X
o
o
mHXQ>-F - H 2
X 2
o
-if
i—i
2
<
2
f:
3
<L
1 —
<IX W 2 [C D 3 X -1
<X X
C_) t—i 1 —■
CO
3 ?!
i—i
X
Dj
X
o
X
O
1 —
XXX *-*—.2 XXO
OCDUJXxX^^CL
o X
X X
t—i
X
-J
<x
X
CD
X
X
• Ua
X
CO 1 -
H<tH
II
o
X
Z?c
CD
o
X
•
o
mH X
O
<L
2
X
X
f—•
X
2
o
• 1 —
<t
mom
<z
CD
m
O
o
2
OD
•—«
*-«
X
x x
UJ
<£ ~D
o —
CD CD <t X c
m >
'H XD U
X f— I—
X 2 — 2 . *-
CJ CQ <L 4 -, 3—4 F^ —4
•> *>0 O UJ O ~ 23
CL ffiXJXL i fl.X^a.XX<CXFG
o
x
x r- x ?:
X —' F.
UJ O •>
CD CD X X C
ST. <
XX-J
O CO
<L X X
LHCCD
2 OD •—
3 _J UJ
uj ? jo:
CO
UJ
X ^
^QQfjK'jJ-Ot? S ro m
eg ho U J -sr tx: c^. — cc ro rsw ^
<I<t< 7 '<?«tSC 7 ' <C<tC 2 C^i CO C"
OOOOCvOOOCDo^O
-< <t CD
t— x> a: <i
u: *: x ru
UJ
2 >
e
o
O CD (-
O J>
* m
O C O KLX N H
cj <x 2 2 o 2 . x
< n i hQ t x
X OfllDD X CJ CD <J
<XO->>JJCUJO-W>X< X -1 X X => X >
HZOCC-XJ. 2XI02c^!XNUIG^020
od —i x t > o j —J o—it/ja. o.r m cxjXJXm^mJ-
cd cd
JO Jl>
X <1 X o c
JQoja. 5:
X > >
200
m sr
CL X
O X
X “3
O
X
X- if *
CL 2 {/I UJ
FI X C >
“D X aD <=■
I— CO
UJ UJ
X t— H 1
O 2D (
<s 2 n :, .
■if * * .13
K-—covo-^invcr-oocT-Ki — coro «r m vc? r~ co cd s —• co ro m vc; r- oc cr <s> —• coro<rinvjr>-coc 7 -'S — cOfO^^vor^-occT'ts
- - - - --■ — — CO CO CO CO COCOCOCOCOCOrOrOrOrOrOrOrOrOrOrO-^T ^ ^ <r <r <nA ^ in JMA lA lA iTM^
rO^'O'OfO.O'O'O'O'O'OfO'OfO'OiOfO'O'O^tOfOfOi'O'O'OfOfO'O^fOfO^fO^fO^'OfO'O'OrOKirO'O'O'OfO'OiOrO
K^GIORKSSOOKISIKS: GGGGGGGSSSGSSSGGQGSGCjCG5JSGSGG
o f-* x f uj
CL CO h CD O UJ 2 — X I— X
F. <1 L n ' 2 H 2 3 3 D 2 X UJ
DUJhhOmUJUJ J WU1I
jiDQLO J2ZOXH3
mUJOL'<U^C4<lOff^
v? m m r- m vc> — s ro <xqc~
<x <x <x <x c <r < 7 '. <r <x <i < 7 ^ <r
CJCJCJCJCJCJCJCJCJCJCJCJ
JH S H2 >- 53
W<mWXJ<HH
nHC^HHh^? —»COJ—
OD> mmGHDUJODIiJUJ
CC CJ CD X CJ ►—I F? 2 C 3 f - ’ f -1
<t
<r
CO
CO
K DO
<
CO
s
d:
<r
rO
o
o
s
o
S CJ
CJ
CJ
s
CJ
o
s
<i m
X CD CJ
s
ID O'.
—
— — rO
x co
m in oo
s
n- <r
<x
VC> X
s
.n
X
in
X
VJ X
o
X
<r
UJ
CD
o.
o o
o o. s
<r
O rO
CT'
<t CO C7D
—•
c-
VC
■^r
X
ru x
c
X
s
X
DC
<c
CJ CJ
CJ CJ s
o
CJ S
CJ
O S o
VC X
cr>
x r- Cm
ro >n co
O'
COrO—*<7>SC0<Iin
<1 co —
in X rO
^<rcc
<r m ro ro ro CO
<r O'
CO
— X ro
07 X
rO
—• ro
— <c
CM
CO cm CD
CO — O
o
S s X M3 03 CO
CO X
co co x
x r— co
m cj x
COXCOf^-COr-
CO —
CO
x r-
CO
07 07
O
X CJ
UJ s
x m
X
S'
X CJ
CD CD UJ
xo-
<T in V£>
o> C
<1
c
CDJUQXX
CO UD
vc? a o
Q X X
ts —. <T
in0D^<EU
CD ts
—
<r in
07
r~- od
C7-
uuu
CJ CD
CD x;
X X 3
X CL CO 2D
CJ
■05 lO
vo
vo n- r-
r- n- t"-
r-
r-
f— r— r^- r-
CC CC
CC CO CO
DC CC CC
^ C7>
(?) CK O^ CK 0~ 0
o< <t
<r
<c <r
<1
<i <r
<t
<c <t <t
c <t
CJ X
Fl—. co
m
C 3
2
H < Q
<t <r
<c
<E <t <L
<L <C <C
<1 <i
c
<t
<£. <t <t <t <r <c
<£ <C
<r <t <r
<1 <c <t
<c <r <i
<z <t <r <c <t <t
C <z
<r
<r <i
<c
<t <r
<r
C <£ <C
<z <x
cn x
x <c o
C7
O X
O
2D h- C/D
o o
o
o o o
O O O
o o
o
o
UUOUUO
CJ o
CJ CJ CJ
uuu
CJ CJ CJ
O O O O CJ CJ
o o
CJ
CJ CJ
CJ
CJ o
CJ
UUU
CJ o
<r cj
CD X cj
*-»
X 2
2
m c/d i—
CO
2
OJ
X
X
t —4
•
o
2
CS
X
o
I—
OD 1 —
X
CD
s
X
*
X X
1 —
(.1 A
X
C/D
—«
M
1 —
2
o 0 D
1—4
CJ 1
C/D
•
X
o
XX
03
X X
C/D
—
°e
OD o
X
CD
X X
r-
X
1 —
1 - X
X
0 D
OD 3
o
X
C'-
M O
CD
1 —
QC
o
2
X
OD •
X 1 —
3
<L
s •
2
>-
X
CJ
—1 X
X
* s
CC
{—
f—
o
1 - —1
X
UJ
m
X
X
OD
s s
X X
CD
OD
CD OD
2 4—4
f:
*>
CC
>- x
X
“
cs s
X CJ
CD
X 2
<x
—< o
1 —
o
23
X
X
X x
C/D
s
s s
X —4
4—4 2
*—4 •—1
X x
X OD
<r
X
2
o
m
<t 3
—•
—
OD X
f: —4
X
X -1
X c
f:
2
C/D
1 —
X
X
*-. CJ
X
OD
*— 4
>-
1 —
2
<£
X
2
x 2
O
s
l—
CJ
<z
>-
4—4
1 —
1 —
CL
4—4
X
C/D
CO
CO —.
—1
00
3
L
m
X XXX
X
f. f:
X
X X
X CD
4—4
CD
<CCDX<I s O
B
G
c
G
D
1 — CD CD
c
<r
c
•>
►X
X
•> X
2
x t—
M •*
1 —
CJ
►U *“
•> 4—4
^ 4—4 » (—4 »
X -
m
••
f:
2
CU x
<t
X
X
w
H
B
C
CL Q fl]
2
X
A
D
B
D
4—4
CD CD
2 C/D
<C
X ^4
X
Xi
CJ m CD X UJ x CD
CD CD CD CD <r
x <r h
— X •
3
3
F 7
X
X
X
O
CJ
X
2
4—4 4—4
2
o
e;
>-
01 —<
4—4
3
4—4
l— 31
CD
X
2
2 CJ
CD
X
CJ X
X
X
X 1 -
X X
<
> X >
m
2 0 - C/D 2 >
=> X CD
X Ou
X
2 > QJ M 0 - 1 —
2
1 XH
= OD
<£ =>
C
03
XXJ>XJ >>—0 _ 1
2 > X > > O
CJ (J CJ X ■>
X
*—. CD 2 >
X 1 -
ac nj
Q 2
O
3
fsl
X O X Q
O X <L
i- f:
2
C X 2 O X
X
O 2
X
<E
X O
X M
X
cj <r
O <L O
O 2 > O <1
o <r o h o x
X X
X <t o 1 —
2 f: N
z> n
o
2 x
o
“3
f; _
e:
03 “D
F 0 .CL F
FT. X CD
X-D
4—4
F u 3 q. a;
X
CL —.
X
1 —
x f:
O J X
x o
f: o ^
^ X o
F' cj y: x f: x
X X
X o ^
cox
F <r
f;
—1 X
X
*—4 O
o
o
X
X
m *“■
X
CJ
1 —
X
>-
i
1 — CJ
1 —
h-
s
2 a.
>-
<£
<t
VC? X
—1 C/D
X CO
X
OD
f:
m
F
3
— n
3 <X
X CJ
X
1 —
—4
3
O
X
*— 4
X
1 —
* m
X
-if
2
* * *
■if if CD
-if CD
•if
X
*“*
07
r-
DO < 7 ;
s
__
CO
*o -^r m 07
r~ oo o>
S —
CO
ro •‘T in vc
DC
< 7 ? O
—
CO rO
m ^7 r-
00 C 7 D Q
— CO rO «n
VL? r— C 3 C C 7 D
(S — CO r -3 ^ vn
VC? f-
CC CMS —
CO r <3 <T
in M 7 n-
CC o
■«r
■^r
in
m m
m in m in
in in in
VC? VC?
VC?
ID ID id ID ID
VC?
id r-
r- r~ r-
r- r-
n-
00
CO CC
DC' 00 CC
CO X X 00
C 7 V O O Oi O
O O O O' ^
s s s
s s
s
S KJ
CO CO
CO CO CO
co co
CO CO co CO
CO CO CO
CO CO CO
CO CO CO CO CO CO
CO CO CO
CO CO CO CO CO CO
CO CO CO
cococococococococo
CO CO CO CO CO CO
CO CO CO CO rO ro
ro ro rO
rO ro rO
ro ro
s
s
S S
(S
s s
s s s s
s s s
s s
S S S s S
S
S CD
s
s s s
C 3 SS
s s
s
Q S
s s s
s s s s
G G Q CD S S
s s
S S Q S
s s s
s s
s
s s
<r <x
o cj
s <r <z
so o
<1 <c <z
o o o
<t
o
c
ro
CO
rO
< 3-00 VC?
S — CO
in
VC?
QD CU S 00 DO
vc? ko s m m
—. x s
03 S ro
VC? <r rO UJ ro <L
mo ■*■ co r- o, o
— vnQ^r<i;c 7 irOtO'OUJCOCO — O — rn O'
uju^^n^^ow^cooo cd — c_?
cro<tm(LCJunicr'UJ - o so- <x u_ u. u. u. o <x
r'CQOU}u]o < J'o^ < J , -uJoinuin r^- s s s s o v-"
w uj to o* foe??
uJmo—ccr-coo
CHUU.Q-W'OW^r'CO^cQUJk(M^^^COc7'<I <r q] O QQOQOnUJLL-COrO'^O' CCmOQU-KfOCO- 00K)(^<tCQOpS——K)0'^0'CO CO <£
— — — pjpj^CviCJCOWWOJ(NjCJWC\J f o»oiO'Oro'OfOfOiOfOfOfOrO'OfO'OrOfO^ < T'Vi^ , 'vr^r < i < r < iintfMnininininininin^^3v/3v/3ii5«^vci/3ii?wv/)
<i<t<t<r<i:<t<r<t;<i;<r<xc<r<c<t<i<r<c< 3 :<c<x<c<t.<i<r<t<r<t<i;<i<i:<r<c<xc<t<x<i<r<i<£<r<t<i<t<c<x<x<t<i<t<c<c<c<i<i<c<tc<i:<<r;<i<i;
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
Page 38
324
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
YET ANOTHER 6502 DISASSEMBLER FIX
Dear Dr. Dobbs: Received: 78 May 22
The Basic language disassembler for the MOS Technology
6502, published in Dr. Dobbs volume 3, number 1 (page 6),
has proved to be an interesting and useful program, but ap¬
pears to contain a number of errors. Some of these were cor¬
rected in volume 3, number 3 (page 3), but further bugs have
since been found. I would recommend that the following
changes be made, in addition to incorporation of those pub¬
lished previously:
DELETE STATEMENTS 611 AND 908
MAKE THE FOLLOWING CHANGES (ADDING NEW STATEMENTS 601 AND 645):
240 DATA 14100,35304,56100,56100,56100,35305, 3303,56100
300 DATA 36100,24210,33130,56100,28300,24300,33300,56100
310 DATA 12200,24222,56100,56100,56100,24203,33203,56100
320 DATA 16100,24304,56100,56100,56100,24303,33303,56100
330 DATA 42100, 1221,56100,56100,56100, 1200,56200,56100
380 DATA 23100,56100,53100,56100,49300,47300,48300,56100
390 DATA 4200,47222,56100,56100,49203,47203,48204,56100
520 DATA 45100,43304,56100,56100,56100,43303,25303,56100
601 Dl=-123456
645 IF c=56100 THEN 1000
902 IF Dl=-123456 THEN 909
1010 GOTO 910
These changes correct a number of errors in the five digit
codes used for deciphering the instructions. A bug is also cor¬
rected in which a spurious operand with a value of zero would
be printed if the first location disassembled contained a single
byte instruction. Another change is made so that disassembly
will not terminate if a non-valid opcode is sensed. This change
was made both for reasons of convenience and to allow
verification to be done, as described below. As with the
original version of this program, no attempt is made to convert
addresses or opcodes to hexadecimal or ASCII representation,
nor is any attempt made to improve the nicety of the output
formats.
When a computer program is written that includes a com¬
plex numeric table, it is desirable to devise a method of verify¬
ing the correctness of each entry, without the necessity of
waiting for all possibilities to be encountered during execu¬
tion. For this program, an exerciser was devised to generate
each opcode possible, so that the program can be seen to
properly disassemble every opcode and format combination.
This method of verification is desirable, since the disassembled
output generated by the program can then be considered to be
reliable. The verification technique was performed on a PET
computer, and is detailed here so that it can be repeated in the
event that further program changes are made, to re-confirm
that new bugs are not introduced.
To perform the verification, first load the disassembler into
the computer. Then add the following additional program
statements:
2000
FOR J=0 TO 255
2010
FOR K=0 TO 5
2020
POKE 6656+6*J+K,J
2030
NEXT K
20*40
NEXT J
This program will generate every possible opcode and will
repeat it six times, to allow the disassembler to treat it as
having 1, 2, or 3 bytes. The block of opcodes occupies 1536
bytes, and is placed into the high end of the PET memory (for
an 8K machine). A different area of memory may have to be
used for other computers. The opcode generator is executed
with the following command: RUN 2000.
When the program returns to the READY point, the dis¬
assembler is executed with the normal RUN command. Enter
starting and ending addresses of 6656 and 8191, respectively.
The disassembly that follows will include all 6502 opcodes and
formats. Verification can be made by comparing the computer
output with the MOS Technology manual (MCS 6500 Micro¬
computer Family Programming Manual, Second Edition,
January, 1976, Appendix D). Note that the summary cards
distributed for the 6502 may be lacking the ROR instruction
from either the alphabetic table or the numeric opcode table.
The PET computer output will scroll across the screen at a
high rate. To slow down the display speed to a more conven¬
ient rate, hold down the RVS kev during execution.
For the convenience of users of the PET computer desiring
a cassette copy of the corrected program, I will be happy to
send a copy to any reader who mails me a blank cassette and
50 cents for return postage.
Very truly yours, P.O. Box 575
Bennett Meyer White Plains, NY 10602
M6809 MEMORY TEST
Dear Dr. Dobbs: Received: 78 June 15
Congratulations on “Resident Memory Test Systems: With
an Example for the 6800” in Number 25. Not because it was a
good 6800 program—which it was not—but because of the
reason it was not.
My 6800 based S-100 CPU would no more know what to
do with a LDU, TFR or PSHS instruction than it could deal
with a MOV or CALL instruction. Apparently, Mr. Ritter has
given Dr. Dobbs a memory test program for the M6809,
Motorola’s new enhanced 6800.
Some of the features of the 6809 were described in the
February 2, 1978, Electronics, p. 95; others are evident in Mr.
Ritter’s article. The program in the article shows that the
6809’s instruction set is much more flexible to use than that
of the 6800. It includes long branches, two, rather than one,
stack registers and two index registers with a full set of load
and store instructions for each, the ability to selectively push,
pull and exchange all registers and compute and load effective
addresses. The instructions vary from one to four bytes in
length and appear to use mnemonics which are consistent with
those for the 6800.
I hope that Motorola will continue to make software (and
other data) for their 6809 available and that Dr. Dobbs will
publish it.
Sincerely, Three Embarcadero Center
Kenneth Drexler Suite 2300
San Francisco, CA 94111
How embarrassing. Not being a 6800-er I failed to look over
the code closely, assuming that if it came directly from Mo¬
torola, they must have it working, which indeed they do. . .
on the 6809. I have learned that the 6809 should be available
in the fourth quarter of 1978 at a very reasonable price. It
will be compatible with the entire 6800 chip family, have an
on-chip oscillator/clock driver, 2 accumulators, 2 index regis¬
ters and 2 stack pointers. The 6809 instruction set will be a
superset of the 6800 instruction set. It will have 11 addressing
modes, will be able to carry out 16 bit operations and . . .
when you get one you ’ll be able to run a memory test from
Dr. Dobb’s. -TRW
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 39
325
APPLE USERS CAN ACCESS DOW JONES
INFORMATION SERVICE
News Release Received: 78 June 14
Apple Computer, Inc. has announced a new service which
will provide owners of its computers with stock portfolio in¬
formation and other financial services. Using a telephone link
up, users of Apple II Computers will be able to dial Dow Jones
& Co., Inc.’s Stock Quote Reporter Service for fifteen-minute-
delayed stock and bond quotations. This information along
with software provided by Apple will enable the user to deter¬
mine current portfolio value, short and long term gains, and
rate of return, among other things. At a later date, Apple II
users will also be able to call up current news stories on com¬
panies in their user’s portfolio.
The cost of the stock quote service will include a one-time
fee of $25 plus a usage charge of $3 for the first three minutes
plus 50 cents a minute thereafter for each usage session. It
will be available from any authorized Apple dealer starting
June 26th.
The Dow Jones & Co., Inc. Stock Quote Reporter Service
consists of a large computer facility in New Jersey linked to a
nationwide communications network. The service dispenses
current stock quote information (delayed 15 minutes) and
current and recent past (up to 90 days) financial news stories
from the Dow Jones news media: The Wall Street Journal,
Barrons and The Dow Jones News Service (Broad Tape).
Presently, users wanting access to network information
have to purchase a terminal, such as a teletypewriter, and
modem. For most users, each request to the network requires
the entry of a series of statements into the terminal to log
onto the system and thereafter to enter another sequence of
statements to acquire each piece of information desired.
Like the terminal, Apple connects to the network via a
modem and accesses the network by way of a password ac¬
quired when the user purchases the service. The password is
presented to the Dow Jones network via the Apple II key¬
board. However, the Apple brings to the network computer
power which simplifies and performs the task of logging onto
and processing information from the network much more
efficiently. Moreover, because Apple is a computer, the
amount of information processing that can be carried out is
greatly increased. For example, with Apple Financial Evalua¬
tion Service II—a portfolio analysis program-the Apple auto¬
matically calculates long and short term profits and losses, rate
of return, etc.
To log onto the Dow Jones network with Apple, the user
loads Apple Financial I—a stock quotation program—then
follows the instructions displayed by the program. These tell
the user to dial the local telephone number of the Dow Jones
Network and then insert the telephone receiver into a modem.
Once a telephone link is established between the Apple II and
the network via the modem, the user is only requested to enter
his password to log on and gain information from the network.
Besides the logon feature, the Apple II is also very cost
effective in its use of network time. With Apple Financial I,
all symbols for which a quotation is desired can be entered
into the Apple prior to logging on. Thereafter, Apple requests
the desired quotes from the stored information without fur¬
ther keyboard input from the user. Thus the time on the net¬
work is always spent accessing and transferring data and never
involves costly manual input typing time.
Apple Financial I permits the user to access quotes for up
to 21 stocks per portfolio. This number is increased by adding
additional cassettes, each of which can contain 21 stocks.
Thus it is possible to have one large portfolio or a number of
small portfolios. In this way an investment counselor can
quickly access quotes for each of several clients simply by
loading the appropriate cassette. Moreover, stocks in a given
portfolio can easily be added or deleted.
With Apple Financial II, the amount of processing per¬
formed is much greater. The program permits the user to
calculate his/her portfolio’s current value (up to 16 stocks)
and calculate short and long term gains and losses for each
stock and the cumulative profit and/or loss as well. Thus, an
investment counselor with a number of clients has instant
access to the performance of each stock in any of the many
portfolios he/she may be managing. Like Apple Financial I,
this second program will be easy to use for the investor.
Other programs planned include a news retrieval routine
which will permit the user to enter a company’s stock symbol
and receive a series of headlines associated with that symbol.
The user then has the option of selecting a headline and receiv¬
ing the text of that story on the Apple display screen or
optional printer. Other such programs as this are planned for
the future. See local dealers or contact Apple Computer,
10260 Brandley Dr., Cupertino, CA 95014; (408) 996-1010.
News Release Received: 78 June 19
WINTER has added a new 5-day hands-on advanced pro¬
gramming workshop to their microprocessor training schedule
for Fall ’78. The course objective is to develop those skills
required to plan, prepare, test, and document 6800/6801
microprocessor applications software. The course is offered
November 27—December 1, 1978 in Lafayette, IN. For infor¬
mation call Jerilyn Williams, (317) 742-6802; or write
WINTER Corp., 902 N. 9th Street, Lafayette, IN 47904.
News Release Received 78 June 26
The Personal Computer News is a monthly newsletter
edited by Donald L. Wallace, and is published from Dayton,
Ohio. PCN is dedicated entirely to a variety of reader serv¬
ices, and contains no paid advertisements. PCN features a
regular news column detailing developments in the micro¬
computer industry and related technologies; objective product
and software evaluations geared to the small businessman and
the hobbyist alike; and two features due to commence this
summer include a PCN-operational Software Exchange and a
Trading Post classified advertisement section. In addition, a
Software Sources listing culls the latest entrepreneurial offer¬
ings from the microcomputer media, and an Index to Com¬
puter-Related Articles cross-references features in the popular
computerist magazines. Subscription Rates: $9/year in the
US; $ 15/year in Canada and Mexico; and $24/year overseas.
Personal Computer News, PO Box 425, Dayton, Ohio 45419.
PERSONAL COMPUTER NEWS
Page 40
326
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
FIX AND MANUAL CORRECTIONS FOR
PROCESSOR TECH S GPM
Received: 78 May 1
Users of Processor Technology’s General Purpose Memory
Module (GPM) board, part of the widely advertised Subsys¬
tem B, will find that they can not load or use the cassette
tape version of the ALS-8 Assembler without first modifying
the GPM board.
The problem is caused by the fact that the GPM board
responds to memory addresses in the range of EOOOH to
FFFFH, whether or not any ROM chips are installed on
the board.
The following modification to the board disables this
response and allows locating a standard 8K RAM board in this
address space, so that the ALS-8 tape can be loaded. The
modification does not affect operation of the CUTER monitor
or of the PHANTOM startup feature to the CUTER monitor.
In the following instructions, all location descriptions
assume the board to be held with the component side facing
you and the edge connector down as shown in the card outline
drawing (Fig. 5-1) in the GPM manual.
1. On the front (component side of the board), cut the thin
trace connecting the pad located near the top end of U30
and the pad located under the body of R8.
ZF if ■
£F 011 ( t‘1
p/teli ujo
5°Ht>
FAon Al
FlW OJO'l 2- ( Cj)
-D* 1
uo
To 031-IS
cs
GPM Fix ptn. /u.s-8
i/‘fjrs
The following GPM manual errors, discovered during the
course of the above design, may also be of interest:
Table 3-1: The SI-8 description should read “allows phan¬
tom signals from auto start (on GPM) to S-100 bus”. Switch
settings should show SI-8 “ON” for an IMSAI, if auto start
from the GPM is desired.
Figure 5-1: (card outline drawing) and Figure 5-2 (schematic)
both identify U9 as a Prom B, a 2708. U9 is really ROM C, the
CUTER ROM, a 9216B.
Note 1: This is the first thin trace just above the top end
of U31. This trace carries the card select signal from pin 12 of
U30 to pin 15 of U32. By cutting the trace between these
pads, the board can easily be returned to its original state
should you ever install ROM chips for the ALS-8.
2. On the rear (copper side of the board), connect the follow¬
ing seven wire jumpers:
FROM
TO
pin 10 of U30
pin 1 ofU23
Note 2
pin 2 of U23
pin 12 of U19
pin 10 of U19
pin 11 of U19
top end of R3
pin 13 of U19
Note 3
pin 12 of U30
pin 11 of U23
Note 4
pin 10 of U23
pin 9ofU19
pin 8 of U19
pin 15 of U32
Note 5
Note 2: Pin 10 of U30 is available at a pad below U30. This
pad may be located by following the thin trace, on the rear of
the board, from this pin down to the pad adjacent to the “1”
digit of the number “100” located near the bottom edge
connector.
Note 3: The PHANTOM signal is available at several locations
on the board. The most convenient one from a wiring stand¬
point seems to be at the top end of R3.
Note 4: Pin 12 of U30 is available at the pad above U30
referred to in step 1.
Note 5: Pin 15 of U32 is available at the pad under the body
of R8, referred to in step 1.
The overall circuit will look as in the attached logic diagram.
Figure 5-2: (schematic) has several other errors:
The signal at U30 pin 12 (CARD SELECT) should be
shown as active low.
The signal at U30 pin 9 (ROM C) should be shown as active
high.
The unlabeled dual input gate shown connected to bus pin
76, is really an inverter (U23) with pin 9 as input and pin 8 as
output.
Ed Elizondo 6 Cypress Court
East Windsor, N.J. 08520
2 NEW F-8 PRODUCTS
News Release Received: 78 March 24
Comptronics has introduced two new F-8 products for the
serious hobbyist and design engineer.
The first product is an F-8 CPU board compatible with the
S-100 bus. Complete with 3850 CPU and 3853 SMI, the unit
provides sockets for 2K of EPROM monitor, two PIO sockets,
and connections for six I/O ports. The board has 64 bytes of
scratch pad RAM, and a fully buffered data bus. The Model
F-8S100 sells for $239 as a kit, or $275 assembled.
The second product is an F-8 microcomputer with key¬
board and six digit display. The unit provides audio interface
and speaker compatible with the on-board KD-BUG (3856)
music routine, 2K of RAM expandable through an S-100 con¬
nector, and IK of EPROM with 4 additional 2708 sockets.
Model KD80 sells for $375 as a kit, and $425 assembled. Con¬
tact: Don R. Swanke, Comptronics, 19824 Ventura Blvd.,
Woodland Hills, CA 91364; (213) 340-8843.
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
327
Custom File Routines for ALS-8
BY LARRY A MAREK
6008 East Lake Dr., Apt. 3B
Lisle, IL 60532
Here are a set of routines I have worked out to take advan¬
tage of the tape routines in CUTER/SOLOS and the ALS-8
assembler. The ALS-8 assembler has the ability to assemble
source code given to it by an outside driver in addition to the
normal assembling from a file in memory. CUTER/SOLOS has
the ability to appear like it is reading a byte from a tape when¬
ever asked. “Appears” is important because the assembler
could not perform its operations fast enough between bytes if
the tape was actually in constant movement. By combining the
two features, assemblies can be made of HUGE source files.
The only restraint is that enough memory be available to hold
the produced object code.
To use these routines change line 0006 of the listing to
agree with your CUTER/SOLOS starting address, then
assemble the program anywhere in your system.
Before a tape file can be used, CUTER/SOLOS must
“OPEN” the tape file, so make “OPEN” a custom command
using the address associated with the label “OPEN” in your
assembly.
Example: CUSTE /OPEN/ 0000
The command has three forms: “OPENW m n”, “OPENR
m n”, and “OPEN”. “OPENW m n” prepares a file that will be
written to. Optional parameter m can specify the tape unit 1,
2, or if left blank, will default to unit #1. (Note —two tape
files may be open at the same time, but one must be a read
and the other a write). Optional parameter n specifies the baud
rate of the tape —1 or unspecified is normal 1200 baud, 2 is
300 baud (Note—open files can not have different baud rates,
also the last OPEN command used will control the rate).
“OPENR m n” prepares a file that will be read from, options
m and n are the same as in “OPENW”. Plain “OPEN” will
display which tape files are open and if they are a read or a
write file.
When a tape file is emptied or filled CUTER/SOLOS
must be allowed to close the tape file. Thus, another custom
command in ALS-8 should be set up with the address of the
label “CLOSE” in your assembly.
Example: CUSTE /CLOS/ 0106
The two forms of this command are: “CLOSW” to close a
write tape file, and “CLOS” to close a read tape file.
Before the assembler can assemble from the tape routines,
a file must be recorded out on tape in byte format. To do this
another custom command in ALS-8 with the address corres¬
ponding to label “FSAV” in your assembly is used.
Example: CUSTE /FSAV/ 015F
The command has only one form “FSAV”. This will start
the tape and record the source file in the byte format. A write
tape file must be already open and when “FSAV” is done the
file will still be open. The tape file remains open so that large
programs need not be in memory all at one time. Some words
of caution here—when you are “FSAVing” out a large file—
DO NOT—close the tape file until after the very last section
has been “FSAVed”.
The “CLOS” command will cause any left over bytes (byte
format is actually 256 byte blocks) to be saved out on tape
along with an end of tape file marker. Also, the very last line
of the source file must be an “END” psuedo-op. This is so the
assembler can tell when to begin its second pass. Because
VERY much of the tape is blank between ‘byte blocks’
“FSAVed” tape files will use about 3-4 times as much tape as
the same file saved by a normal CUTER/SOLOS “SAVE”.
This makes these tape files VERY slow.
The last custom command should be associated with your
address for the label “BUILD”.
Example: CUSTE /BUIL/ 0180
“BUIL” is the opposite of “FSAV”. It will read byte format
tape files into the current file. By specifying an address after
the “BUIL” command the tape file will be read into the cur¬
rent memory file until the hex address is reached, then just the
remaining bytes needed to finish a line are read. (If no end is
specified the whole file will be read in.) Thus “BUIL” and
“FSAV” can be used to pass very large source files amongst
hobbyists without regard to memory limitation. Each user
“BUILds” a memory file according to his/her available
memory.
The last thing to define in ALS-8 is the tape file input
driver with your address for “ENTRY”.
Example: IODR/CASSI/ 0091 0000
ALS-8 is now ready to assemble any size program for you.
ALS-8 does a carriage return and a line feed at the end of its
first pass. This is your cue to rewind the tape. The motor will
turn on automatically. When a tape is fully rewound strike any
key on the keyboard to continue the assembly.
Remember, all routines work with the file name as found in
the “CURRENT” file in ALS-8. As tape files are written they
will get the current file name. When reading tape files the
current file name must match the name used to write the
tapes.
Here are some “quirks” I found in CUTER/SOLOS as I was
writing these routines. Tape unit two is 42H not 40H as
described in the CUTER/SOLOS manual. A big mistake exists
in CUTER/SOLOS-if a call is made to “FOPEN” when the
designated file is already open the stack is “POPed” once too
many times! Instead of returning with the carry bit set, the
processor takes off to whatever garbage is on the stack. (I
spent several hours one night tracking this problem only to
read about it the next day in an old “SOLUS” newsletter).
This explains the point and push in lines 0072 and 0073 of
this source file. By pushing the error handler address on the
stack the extra pop will put it in the P.C. register and the error
will be handled by “TAPER”.
Page 42
328
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
For those of you using ALS-8 that is now available on a
CUTS cassette I have found a “bug” in it. The problem is in
the “ASSM AAAA BBBB” form of the assemble command.
The assembler is supposed to assemble the code for start
address “AAAA” but put the object code at address “BBBB”.
I have only thought of one real use for this-when you are just
trying an assembly (to get the syntax errors out) before you
break a large source up into byte format. The cassette version
is supposed to handle this and it does okay until it hits and
“ORG” pseudo-op. Then BOTH the “AAAA” and the
“BBBB” address become that of the “ORG” value. In both the
older PT #1 and the old ROM version of ALS-8 an “ORG”
statement just ADDED to
the “BBBB”
address. The fix is
relatively
changes:
simple—read in
the cassette
then make these
RDBP
CfiSSETTE VftLUE
chhmge td
ECBF
22
7D
MOV RvL
ECCO
FI
C3
JMP PRTCH
ECC1
DO
F0
ECC2
C9
F9
F9F0
00
93
SUB L
F9F1
00
■5F
MOV EsR
F9F2
0 0
7C
MOV R« H
F9F3
00
9R
SBE D
F9F4
00
57
MO’S-' D? R
F9F5
00
£R
LHLD BBUF-*-2
F9F6
00
FI
F9F7
00
DO
F9F8
00
19
DRD D
F9F9
00
22
SHLD BBUF+2
F9FB
00
FI
F9FB
00
DO
F9FC
00
C9
PET
CORRECTION ON MODEM ARTICLE
Dear Tom.' Received: 78 June 12
Received your letter and complimentary copies of the
Jun/July issue of Dr. Dobb's Journal today. It is very satisfy¬
ing to see my article in print. Unfortunately, there seems to be
an error in one section of the article.
The last paragraph in col. 1 on page 6 should read: “... the
system must, at a minimum, provide for ring detection (the
Hayes unit provides this while IDS does not)."
The significance of the correction is that it establishes the
foundation for the claim that the Hayes unit can be directly
connected to the phone lines without an intervening DAA.
This claim is basically correct (except for the required certifi¬
cation and certain other technical details that I allude to in the
article) and I certainly don’t deny it.
I noticed on page 44 of Issue 6 the article “Computer Net¬
work Poll” reports reasonable success with the Hayes unit. The
manual I used as reference on the Hayes unit related to the ori¬
ginal unit. I note the article refers to a revision 3 modem board
with anticipation of revision 4 shortly. On the one hand, this
seems to bear out my reservations about the board. On the
other hand, it seems Hayes, with help from users of his board,
is making an effort to correct its deficiencies.
Thanks for accepting my article for publication and keep
up the good work. Your previous issue (Vol 3, Issue 5) was
really outstanding.
Sincerely, 9655-M Homestead Court
Tim J. Pugh, Jr. Laurel, MD 20810
n
LU Lu
CL
M -4 h- LL
UJ
U X > CL UJ
h-
J -J □ lu cq Uj m
r -1 X
lu
UJ
to
_J_J_J^J Jl Q_J
> (J
F
I UJ
ui jtt _J -j □
•X
UJ QL J— X
CL
►—
X
Iuiuhft.zbgx
Z h-
E X A
UJ
CA
CD
•_) U X' UJ — i X
n ~ cl
X Z X LL
0) u
t—i
r-w
uj lu a. n h- i-
a
Z I • 1 — X
X
UJ
z
F •
ZMUjFz'iujrhH
a X Ll
UJ CL (J X
X
> UJ UJ
F
M •
Luai-X'-uji-a-'Z;
uj □
LU X LU CL A Z :3 □ LL
K
r
1 —<
F >
X
Z •(•
fp
r.
F
CL -J > W X > O Z Z'
Hd J
x^u|U.iu , - , F a
X
X'
►H HI
Z 1
Z' X UJ
1
□ (J A E A Z'
Z- LL a
ho. JClijXkUJiIL
Ll
UJ
X LD
$
0 X
c-j
LU UJ F A U
UUJll
u. ►- x u. <: :• FUZit u
F
X X
X
• □ X F
J
J
F
LUUJQFI-EUJUJOF
A ^ *-• F
Ll lL A X UJ LU I - * LU UJ
— i
X X
z
X
X
E F X
<£
*-
(/>
jJI-WEIUJ'Im
ZA Z
h-a A J 0 . X J I
□
U. \ X
lD
X -
A
X x«
1
UhIUlL>_i>Q.uJll
X Z' -1 OJ □
Z u. > □ o »- a
1 o z
X
•
MJ
X F Z X
It
£
(k
U U. CL 3 <•') A l- W CL Z
a x w a u
LU Z □ Q. h- CL 'I> ►h X
u.
Ll
□
C-) UJ CA
X X - F
□
•r
UJ
A
LL XXI— 1 il h q. UI
_l
□ mi-i
r x n
A
XXX —
IL «
t-
o UJ UJ UJ
Ll IX A Z CL Z A (J F J
\
1 »—< >-«
UJ *-< E
X
> □ X
□
o
X X X X X X
oua.
jluz m ZDjm ' x
LL
A ui
».
XXX
X
F £03
in \
u
x X x i u. i j '-'j a * fn
OJ O XXX
OttlUttH x X X D U. O
Z CA CA
A
□ X
X
X □ X
UJ K-,
F- 1 A o « oj oj o ^ —
hCOF hh
UJ X X
Z
A X
00 •
LD 'X X
z
x
q v' 9 — 9 I* o;i 'X op 'X*
X
: E Q_
A
M UJ
u
X
+ + 4 + + + t + 4 +
xxxxxxxxxxxx
z
3 X
z z*
't
K 1
i
o
Q.CLQ.P-^Fiia.Q.a.
•=■ Ij' f - L T A O' O p C'V
•£>
z
Z X A X X
X +
?'t
'i
o
UJLUUuJLULUuJLULULU
_ X
□
Uj x x a
X A X
D h
o
1 — ►— I— I— »— 1 — 1 — 1 — »—»—
X X X X
O O O O — O O |V, CO r- '.£1 OJ
X
CJ
XX-
F
Zi E D n
I
o
DDDDjDXODD
o o OJ Ll
AAAAAALULULULULULU
L-l
□ X
O
A Z' A 3
. IL
•
o
O O o O O (J O (J o
O oj CO’t o
o o
UJ
: CA F
F O
A Z — n
uj Ui
•t
X
► z
— OJ
J h-
►-<
(A X A Z —
H 73
U X X z
IL U
I
F □ X
r.
A X
i
XI
X> D D X X X' Z' X X Zi
X Z* Zi X X
XjjXjj.'j X _i
X
X X X
Z X
> —
XXX-
t U>
■I
0
Q. 000000000
0 0 0 o a
00 00 0 0 0 00 0 0 0
G- 0 0
UJ F t A
X «
X X A X
P 2
.j
UJ
LulDlulululuLululuUj
LU LU UJ LU LU
LULUIULUIULULULULULULUIU
UJ UI UJ
X CA X Z
X U X O
F H
a
Z □
U F
In in
XXUX-*
D D
>-
&
ZmFf a UJ K h-
o HOJh
O
X
X X X X Z
U
CQ
UJ
UjD>?-Q.'XlLA^ —
OOhhQ.
UJ fl. (L U. U. I 0 ) i Z H L
Ll
X
X
— □ CA
(A Z>
r
h-
CL J«KZ 4 Jj-Q.Z£
OJ O H-. n
J L I X X O X CL X I
X
U X
F
X :
Lu
z>
a u m d. -i i h (4 d j
. nwrzl
*- □ □ A A 3 X O X
LL
□ lL X
X
♦ ♦44
4
4 o 4
!LlJ.il 20 Alhll 2
4 W ( -) X X K
4 U. A LU A *-« (/> X X (,■ > 3 U. U
4 UJ Z
♦ 4
4 4 4
4 4
4 □
o oj oo tj- in •>£» h- co ij. o in -a n a> cr- ® — oj co ^ in vd n od o> ® — oj co ^ in ■£> r - co cl o oj co in n co x. ® — oj
o o o o o o oooo-h^h — — ^ — oj oj oj co oj co oj oj co oj co co co o*> co co co co co or* 't ** m in in
O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O •=• O •=• •=• O O O O O O O O O O O ■=■ O o
oooooooooooooooooooooooo ooooo ooooooooo oooooo o o oooooo o
X
-J
UJ lu [
LU X
UJ CO
F CL
r z:§
z> —
. ■ UJ
til5 x
l£l Q_ (/)
F
a z 3
CO ►
c
F
se
a:
Z UJ
sans!
A >
z z
OJ □
OJ
+ CL
Ll Cm
O Z
a z>
CQ Z
6 ■ a
DKiur
fflt— D LU —
X 0 3 1
a a. n p w
£
□ 00 CQ
F U
UJ ±
a - S
cq x a. u. o in
r A (.) r * ».
x n .kip«
st;
x >
D A
□ I
CA UJ
UJ LL
Z UJ X
ui
JI«E
— □ w
> lo a. —
□ JEtD
Z o LU o X
r '
x w
z
, f-
I't P t Q
_ X A X _ _l . X
— n > x ca x x > ~ 0 '<t ~ -J * ~
Nfl.IuhjItPClLI-XX>lif->r
“HJOEtOl J O Z X CL CO J J Z O X (/> Z —
X
CA
oo 4 in x> n ro ^ o cu co 4 in ■ 0 n coco o oj
in in in in in in in so •£• •£■ •£> x •£• •£• •£> •£• •£• r- r - r-
o o o o o o o o o o ■=• o o o o o •=• o o •=•
0000000000 o o o o o o o •=• o o
000000000000000000000
0000000000000 oo o ooooo
ooooo 000000000000 oo o o
00000000000000 oo o 000 o
• O »_• O O C- O O' O O' O O' O O'
O' O O' O' O' O O O O O O O' O O O O'
O O O O' O' O' O O O O' O' O O O' O' O'
O' O O O O O O' O O O O' O' O' O' O' O'
O O r-i o
o
03
O O CD O CO —
A o a O
o
CJ
AO CJ A 01 O
X - CD N a
X CD UJ In N
0J —
— — a a o u in LL
X 00 N o O 0J •=• ^
in ^
loarujdujojix'ojin
X A tt' sD X '.U — — '-D A LL
0J CJ r- X ■=• CO 0J — o 0i x
OJ CJ CA X CJ
XUN
CO x
OOOOOOOCO •-£> A
XI O CO
rt N
03 A X X — OJ in CO A A o
_...... « aj ^
lOOHHHHHHHHdJ 0J 0J 0J 0J 'IJ CO CO CO CO
■ o O O' O' O' O O O O O' C- O O O O' O' O' O' O' 000
> O' OOOOOOOOOOOO O' O' O' O' O' O O' O' O'
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 43
329
P
X
~ £
I X
X
CJ 3
P
X
1—
P
Z:-
p
h- CO
sa
P
>
d
E X
i—
R
CO
(-0
HH it
UJ
s
p
□ I
> in
X
3
X u
X X
UJ
CO
X
I
CO
h-
X LU
X X
H
X CO
3 X
X
D
X
X
3d
3 X
X
p p
LU
R 3
□ (J
« X
X h-
P
x
d CO
R
v z:
± X
UJ 0
1— •—<
3
•t p
h g
P X
CO I£|
r/i
gf
X
t-t p
P IU
CO
H P
U X
X X
X
CO
3 CO
3 3
p p
I/O
d
HH >
X
P
X R
I
P P
3 R
I CJ
X d
05 X X
•* R R
I .
co <r
^ i
P 3
□
x o
J I J J O. Q. (lh
o a i g □ n □ uj
IU J CJ LU X X lL X
r ►— .
x p
~5£
□ I cj
\ :
a; x l
w £
eg □
CL »-•
a. p
co i'
I CL
“ J
n a.
r □
*-* X
2&
iii x
♦ * ♦ ♦
□ LU CJ HI
X CO
CO □ CO > □
<- :i r co 'i _i
<t x 2 cj
0. _l X CL
>-
UJ
X
p hh
i :fe
K • O
CL CJ
P □
x u. □
X UJ >•
CO J J
ttr«
5 3 §
CO UJ P
CL CL
d co
I y— -
UJ r UJ
t- fu cl
□ x x
Z2h
I
X P
UJ X
I
co
R X
X X
CO X E
1 X
p
56’
f d 3
3 X
X X 3
lu X
X P E E
1 X f-
'-Cl lL I'J P E a. H [
x □ e x Uj a: 3 :
SlHlIhhHI
•“* CO f— P
ia«iifl.h
P ' J J Z u. Z H
2 g □ ii h it _
« ru «r c-o CL cl i- co 3 th
3 ct *-< N nr r
JJU"'H CO
♦ * *
J'IUj a: t—
X R 3 X N CL P
O -I □ (J “ X □
-X
3
CJ I-
a h
^ “ Lui
CL UJ UJ □ (J h-
IUEZI- LU -I
R X X J JE
UJ 'I Z Z J I! h Q. □
5- UJ *• U P X
'X 1 Z LU I UJ XU
X ~ P J UJ D
> hHhI CO h
lUEMUZllf-
J X - ~ CL
h zml iu □ o t a iu
lL R 'X > CL X U) L
• IU
co m co
ui x □
co lu _j
a Cl U
P
X P
H
i CO
3 LU J-
CO 0.1 —
□ □ X
JPj
(J
U R
UJ
q£
57
P lu
X
X
X IU
X R
IQWEIiiL
P P
MHH jHltP CL
X X > X X R X X
X
UJ
X P P
X X X
PS :f.r
■ - X IU
!§S3fS
& fe
IU IU I
tv g ^ a j
ujEt^L
_ X J U H(J3
**. IU • IU >— *—• IU hh x
lc LU Cl IV) 3 P -< PI- > >liMDp|-
X X - X CO H3RX <t j-±
iu — i— u x p m CD 03
X UJ IU X P _ K LU , LU P h- UJ r UJ 3
P
I □ IU X X X
: I
P □ U5
P
CJ 3 X □ P h-
: O
® CJ
D
R R R
C O M
x
IU X X
R d I
’t
P
P IU EPh£|l.
E P 3
X +
X
•«
- I x I — P Uj oj
X CJ
U R IL
X
UJ
iiRinzfizcLiih
3 : C-0
3 3 3
X
p
r. r. r. > » 3 □ X Ul
3 P
R 3 R
lu
r— I— IU n. uj ijj U- r— uj uj u h- iu Z UJ 3
IU - EXXPRXpPX mC0>
cd x .j 0 -) xphiztHiup co x x x C Uj
— LlI •—« i.- .i X ' 1 P X h- U P X *-* 3 c- i 3 ip 3
SjLcJ
p y~
p i-
PU|
U P X
h- X
P — X
o.i x
□ 30
P X
.1 .-ij
0 ) i— w l— i— y x P t-i tk
ph kp -*«:o^pp hh h-duj
ids id 135dS -
_ “ X X X P
X R 3 X X C
3 _
•303
*sdl
O-J _ _
□ p p x ►-* x x r j p x X x x p
o i x o x r j o z - - --
P P |_| P - P o
P ± X Kj p
x x x p e o x p n x x x o
O X O') 3 . J O 3 X P (J 3 CJ 3
.3
a
j
□
p
g
op a- o oj co
rt *t 10 UO in u*
rj- U-J r- CO IT, O -
u _ < uo ui in u‘ in •£•
•ij
0 -o
•3 ’t UO
VO P 'D
•-£• N CD iO o « nj (<)
'•£> • £» ' D ' D N N K N N
in i£i [•- CO &■ o r-. oj CO
r- n K r- r-- co oo co co
■& uo
0j 05
•d r- od a - w' — oj co in p r-- co a-
00 CO CO CO X' '3 if- >T- I?. '?• if. I.T. X. 1?.
■ 0 ? cr . 1
^ oj '■
> O O O O O '
o ^ uo \D r - oo ct> o «-i cvj
oj oj ''a «:.j oj oj oj -''j oj oj oj oj oj oj oj oj oj oj oj cu p oj oj
u o
’t R
X R — —• — cr .
05 O CJ R P fJ
05 05
0J O
- oj in uo in- uo no uo co « r c
g g 'J ip o g g g g g c
r uo ^ x u. n
U. 0J H U. H P
X P 0J CJ 0J R x 05 R X U 05
05 U CJ 05 05 CJ 05 R CJ L) X R
:• U in lL U rt N 05 U
:• OJ O rf CU - o rf it,
< ^ X' RhXRiT 05
J -« c- u 0J 05 (J R CJ
U - 05 N U t
P 05 P U0 0J —i
N -
IU o
R U0
R 0J
^ o rf it 05
^ t£i ^ C- Tf
05 K,Oh
CJ P CJ O
UO R ± CO
-| R O rt-
0J O 05 U CJ 05
t CO 0J R U.
•5 R O X
05 ' J 05 CJ R ij 05 P CJ U R
1 R iu u il il iiilu.Il li. u u oj + r - a* p p ^ 05 •£> a-. X cj o o u cj u oj rt r- x r o co <o -o <0 -o
1 y y y y y y y g y g gi g m m r r p q p p p p p p p p p p p u p u u u o o o o
■15 •-£' •■ill cr - ULL « t r - X P P U CU UO 05 P P U 0J 05 Xi ct-
Z- O O O O O ~I T-. r-i rn ^ OJ 0J 0J 0J 0J 0J 05 05 05 05
X
C-0
ir
p
I
X
C- P X
h-
p
0
R h M
R
it
X - P
X •
p
p X
P •
X P
X
X J _tf
X •
p
0J
Cu
« UJ UI X
III D P
• T wi-
:• p 3
‘ * £ '
i
X
3
□
■ £ X
X UJ
J X h-
3
p o
^ -I
H
Uj
LtH X •- X
P R P h- X
r x a X x p
$ 2 P 3 X 1 -
(/) P X (/> □ P X
X - -I IX
I UJ J I UI I— 3
P
c- K
C- i hh l
■ P X c
<1-3:
P
X
i£
R X
r Q
11 u <
pp >-ip •—< P P 3 I
X X U I- U X 3 □ X
3 E 3
XX X
P □ 0J □ I— □
iLHOIhl-HhlltEH 0 J
P3X-«3X^-5-PX3 2
X 3 > ZP r. 3 X X ■ ' “
' CJ X I 3 X I 3 I- CJ
CO
*—' |— |— H
I - I
h- C ) h-
W P
p I-
r- ui 3 —
p □ p p
3 I P 3 —
□ “
cu a
PhH
— 3 3
3 □ •
13 3 1
R $
P X U
S P P P P
X . I 3 R
K CO • H □
• □ X r-
>LhP PP liJ
_X CJ 3 R I— 3 P r
R 3 3 X □ H CO 3 3 r3
I- R P X H CO 3 CO 3
^ □ P IU P COR i-i CO 3 f-
« 3 > lL > P 3 P X X
CO □pHPQj3H3i5 D
X X 0 3 3 X □ U □ X 3 Z)
h- '55 U 3 05 I- R 3
— CO P X CO « 3 3 IU P 3
3 P X ' J P * 3 CO X r
3 X O CO X X 3 X C O X I « • .
□
2
p _
CJ
d
3 X
p d
,AJ *
co X d i- p
3 U 3 H X
hl-Zd
I ~ 3
3 h- >
C ) C -0 r,o J
p
CU
X h-
3 X
*■ I
• R 0J .3
P P
P P I
- ~ r j p p x ~ -« — n p p x > x c-o x x - hh
: X 3 X X R X x r j X X Z X X 3 d P 3 E d X > r J CL
■ - .- - - X 3 E □ E X o
X I P P
X X - CO 1-1 P 3 P X ►- -
I- □ X 3 X X >3 X R X X N X _
CO X P X P CJ P CJ P P CJ 3 P O 3 CJ CJ P P CJ 3 P 3 CJ 0 3 3 C-
3
P X
•-H »- X
N > X N 3
X 3 O X 3
□
X
X
R
3
R
C-0
X
1
CO E
h-
Uj
LU
M
CO •-<
K
C-0
1
UJ
X
i
i
E
CO
•
CJ CO
p
f-. X
X
•
X
CJ CO
u
X
X UJ
d 5
E
X
p
XXI
UJ CO
1 X
►i
d
p
X P
>
R
R □
X
c-
UJ
u
X
P X
. -±
E
PEP
U P P
C- P X h-
I
CJ
CO CO X
• ZE-
X
«£ 3
3 P
P E X -
h-
co
►H
X X
. X
i e p a
LRhLui]
L Z □ I
X
R
*-< 5-
UI
UJ
p a
E^uxd
E h r o p
%
□
U
EXE I-*
3 3 d d
ID P
IU P
X R
U P X
C O h-
• 3 X
P 3
~ a
X X
p ui *-< ± ± I P
EP2UUIU.I—U C
x d
E
>
D
p
I
d
d u
1- X □
- P d X H
\—
iu £u
X P
x
□
R h-
co x
x .
V
h- R
co g p r— '
X
> CO
H
fO
CO
X
X
p
P
R P
CO E
1- X R X X X
kH
X C-0
X
lu u
p
f-H
p p
U P
p
R UJ
IU P
XPEHdd
d
CO X
IU
1-
X
u
X P
□ R
IT.' CD
X X'
X
X X P P CJ R
X
3
P CO
U .
R
>
rt
*— 1
h■ h-
E CO
3 P
P
E
X E
X
X
IU
I
b-A V
*-« X
R f
*:-
P R CO
P
o
X
CJ
X R
P
E
R
~x :
XX E X
c
_i M
X
r 3
M
P
X r . X KH I
LU
W I R
R W CO
X
p
X
CO
Cf X X
x d
W I X
I X
I X
1- 3 CJ P (J
X
p p
E£
X
CO R
h-
♦ M
III P
3 C O CO CO 3 X X r J X X 3 X P
3 3 ;■ 3 Q R X E X P 3 R X
IU X X X IU P d 3 h C0 p _j i_.
X 3
P R
x »-
X E
IU ^
3 ~ X CO P X >h ~
S X RjID3ud(L N X C
P P X O X 3 “i 3 O 3 O ‘
0J
h-
P
♦ M ♦ .j o
05 ^ IT,' • U N 05 '?• >=' -i 0J 05’t U5 'J5 N 05 O- •=' « 0J 05 ^ IT- 'U N '55 0- ■=• — 0J 05 ^ IT' X' f_- 05 '
r _" r j f j r j r j r j: r j ® ® ® ® ® X* 05 ® ® 'I' '7- |J- 'J- 0- O'- O- O- O- O- O- O O o -z- o J
) r- x> o- o ^ oj o-j rf m -o k 05 o-. o -< r
, ^ oj 0J CU oj CU '\l 0J OJ 0J liJ 05 05 C
5 05 05 05 05 CO 00 '
05
o
0J
•55
o
v—i o
0J 05 CO 0J •=•
0
CJ
p
•_1
°
o
o o
P
P U
o -z-
05
N
'£>
p
W
r-
N o R
••U
® U0 N OJ •=•
0J
■Z.
p
4
in
R ® IT'
•X'
- rt r -
0J
^i
in
R
R
X
UJ
X
«-• UJ 0J
R
R X
-IPX
U
R 0J
'P
CJ
05
0J U
CJ
0J u o
r -'
• J 05
0J Cl
in
■£'
r-
X R P
r r
x
CJ
U. 0J rt
r-
X R
o 05 IT'
05
C*5
05
05
!-
*t
4
4
rt
f y y*
lr.
in in
•Xi *•£• •£•
o
o
o
o
O
o
o
o
o
o
o
o
o -Z- -Z.
-Z'
o o
o 'z- o
O I\| 05 o
P P P P
• 1 * o o in
-i '55 X' -
CO <=•
|J o
05
K
LU
? ® ‘D 05 0- R R IU -
R
U
in in In*
IU R O
X N OJ O Oj
*3 R O 05 CO
05 R
<J f_i
’t 0
X R
O O rH
U 05 R U".' •=• X'
O O CJ (U X
*-< x in R *-« X X N UJ X LU X
0J 05 P O UJ U R N U 3 U R
1 rH (JJ 0) ^ t N t' W C
g u u oj if' uo ir« in in in x> r g u •=• 05 ■£' n &- o uj
't- 0 -. ® X X X X X X X X X X X R R R R R R R
• O O O O O «
Page 44
330
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
a.
cE
E
UJ
CE
LU
£ a
X □
R Uj
X -J
UJ rt.
UJ»—<
UJ . «J u_
B ur. >-
d z -- • u. lu
-II d □ X _1 IuJIL'I
x- L' UJ M i u □ I □ Q
I ll -I d U. R CJ Q. 0.
•i □ •:-■:< u u □ iid
U h- pL UhE'
> h- 1 /) g u u g d • 'i j
■i u u r cl h* r □ i id u □
• ■ «d a. ui o CD UE J«wl
h- g a. 0 . z; ll
— >* UU _J □ d G
r r Qo.it z: uu_x
d g z d * 11 •- - □ cj
iCLlLLllUhE'jLLlEwU.
U
a.
>x
d
£
u
Ql
□
u
lu
U
G
R
R
d
*-»
>—<
UJ
d
d
ii
3
&
d
ft
a
CU
£
U-
□
R
r
n
cj
CU O rj- X) 00 cu If) o in rt U. CO R N o
•j- d o .T. o cc oj I •=. cu ^ it. rt •=. ^ n
—< © ©©—<*-« 0j —• CO Oj CU
o •=• (J © © © CJ © © © CJ © © i_i © ©
n 11 m r UJ 11 co. _ _
d cd iu pj iu □ a Uj z □ >- cu lu q d g
□ ihhirvzllj jrKQ.Q.DZi
ji jriEHi-Miii.oLjt: cd cu □
r u cj Uj u u. 1 _i □ ii d cd g 1 - 3 3
(i I • 'Jl Cl N o [j. if) « n K o fi o h O yi
□ Uj R O © If. CJ CD UJ If' Oj L IP o Q -
© -. nj — o o © co © © oj N co
© © u O © © © © © © ©UR ® ■=• u O
I -J
: 'l ■ ' -J u
X 'I 'J _J
Z W I U i- '_i u u. ^
— J d CJ 0. “• E CJ *">
fro
G
U. d
•- r j x
r =rJ 2:
u
u
u
CJ
o
D d
d r r
> I z
to
G frj
G
m to
G frJ
G
G I
o ~ •-
E JO
d
g d
G
d
q d
G <±
G
G CJ
-j
d
t>
r
E
r
c
lL
u
u
d
d
d
rt
G
G
E
□
□
□
□
7~
r
d
cu
OJ
© ©
U
U 4
4 U
4 ♦ d
4 4 d
4 4 3
4 4 3
4 4
•X> CD
•£• r_- *
'?• •=• 0J CO
m ■ £> N CO
cr.
° -• Ol
n y in D
K 'Xi 17% O
OJ 0j
u o
© © o
>_. —. —.
»-» •-*
»-<
Oj CU OJ
CU OJ OJ OJ
OJ CU OJ CO
CO CO Oj
C'j CO Oj
CO CO Oj CO
CO CO
CO CO CO 00
CO
oj CO CO
0j Oj CO CO
CO CO CO Oj
0 j Oj CO
© © ©
© © © ©
© ©
© © © ©
®
o © ©
© o © ©
© © © ©
© © ©
r n r - r ►
•M«a.hzi 2 a.h>
: Z E □ Ii d 'J > □ IT ;
> Q 0 CU ’t rf OJ r-
p © © © © rt. ©
:■ © © © © © ©
3 1 I wzh r r u oj to (i
lu □ iu*-_id~op_iGDb
t; - PILjilEJD 30 lujMjh
JDttZDUDHjHUMUZU tO
•r 0 Q o Lu u lL u. _i r d d’ to to g d 3 3
^ © Ll
rt U. ® G rt
rt LL o O rt
rtliOOrt
rt LL O o rt
U1 OJ .jj
IT. rt OJ OJ rt
in 3 CU OJ rt
in ^ oj cu in
in rt CU CU IT'
cc*
©
— •=• vD
® llj C'J
cr. o u oj ^
a> o lu cu r*
0. o LU cu d.
d. O LU OJ cr.
(J
(J
© ©
© G U
OJ rt U-. OJ
rt OJ rt Uj rt
v- CU v ID
^ OJ rt in rt
rt '1J t in rt
cr . in
X) y -r CO G rt IL G Q O U. d ® CD ®
• £. ©
© ilj cr. G •£' LU ^ O O © ^1 u. CC' 111 ^i
'f
G
O co
Q Qj »-• IT' CO
© oj o
u -• u j d in
u cu in ll in
UJ ^ IT' IL OJ
LU CU If' IL OJ
CO >=•
-i 1 x i O^rtrtrtOO © © © © o ©
°
(J *t
© >1 © © p
•U U j U*' OJ
rt CO rt rf <fr
rt CO rf rt rt
rtCOrt^m
rt CD rt rt Uji
UJ G
© O © UJ © G © © (J ® (J O © © (j
oj d
in q
- d d
f - u oj co x* d oj
—' *-« uj OJ P
in ® o . £i cu p
ipooxi C'J G
in o © r. m g
in o o •■£. r. ir- g
OJ CO U O UJ IL G
r - il (j oj co oj ■_>
OJ rt rt u j o
in OJ ir. rt in O
in cu in rt in o
in oj in rt in rt o
IT- OJ IT. rt in rt O
1' '£• CJ G •=■*-. rt N CO I © U © CO '■£» *0 ••£>
'I 1 1 I « w ft Q w w Q Q u U (J 'J <_«
r u y u
U U UJ u
o © © ©
© rt. *rt *H
© © © ©
OJ OJ CU OJ
© © © ©
•XI N N N
CU OJ OJ OJ
LU G >
Cj G Q
v Q_ CD d tl
OJ OJ OJ
I Ll □ UJ R
cu cu cu
(j □ —i i r
© © ©
d GOGUJ
z R © r —
i l' Ll I > © d d I- R >
□ ZZhiQCUZilHH*
CJ J«> jO-HtrilCt
LL u — Z □ d ( 0 t O I- Z- 3 3
d ~
r
|SE
d co
: 3 '
3 g £
R
»- CD
r co
:5i
B
.j
(t d
R Z
CO
LU
r
3
r r
kS
iis
U. 5
-I U
d -■
W O X
E
- u
? d
fl
6
IU
CD frl
d
h- frl
-1 _J
UJ
3 ft
D J
3 rJ
R
□
CJ -1
hQm
d
-1
ii r ll
Ll
UJ
a r
fV ~l p
iL
d i'D
R
d Lu □ j d
cd y
R
□ d
r x
XOtf J IU
n d
c
u. o
^ R
u d d d i
• d G
uj
d Z Q
• d
d
z z
UJ 3
a. c j fr )
. I □
d
[D i-h
e
d co
Z LU
R G _
3£ !iJ£
QJ 0 .II
C|j DU*-.
to
a!
. J CJ LD
i£i h d d iu r
DR Z G > U
DLODZDhI
r i tt 'I G LL h
is
d *-•
□
u £
G d
R a
to r
lilfi p
-J r r
HZIU p
IL D J □
□ HI U
U. O U.
G p □ S S
r R d i
u : ZU.U
R r id ’ r
u -• u r u
0 R — ID
fro
d
UJ
t V .
3 -jiu
X- lu IU
d X E I
R -I Lu no
HiRUJM
r X D d
D (J □ ll
U R □ d
R > R t -0 ll E
uj d Lu uj d d
ID to _l d IU G
u u
z r
□ a
G G
R J
Z CO R UJ
m3
E
d
P« 2 =
g£ E gn
d 1 d u.
R R d R
> LU 4. D CO
Z G LL X □ frj
EE CD EL)
E •'
IT Z
z
LLDU.DE
L)J UJ d
X
X
>
z > UJ UJ -J
□ GOG •
D d luJJ
ft rrJ
d N
O d Q X G G E •
d G D d •-*
W* LU G G G G
3X3IRIU.I
□ •--Id
Uj g
> •- N HtXXl N R
-= iZ
D
□
d x d e
? ?
PdZ>RZZCJZiU
1 ft
LU h
<3
UJ
(J JUD
R d
E CJ > E fr) — — G ■ d
ft
G G (J
LU
uj d
□ Z LU
UJ d
> R
Z d CD
G G G G I _J _J
i i i 3 c S g p d □ o i
_J to _l to Z _J d U d “I |_1
U d
r e
- “I
d
R
♦ 44
) f in 0
J 0 J 0 J OJ
J CU 0 J cu
:• © © ©
r-- co
OJ OJ
0 J 0 J
I^J CO oo
0 J 0 J 0 J
© © ©
cZ liJ
□ d
e d
0 J Oj * Uj -jj
Oj 0 j CO CO CO
0 J 0 J nj OJ 0 J
r
♦ E
r - oj c
CO 0j c
OJ cu c
£
I
(J
S □ 1
U. R
4 4 4 4 4 4
d
4 LL
□
5
-J □
*- r
K
r il .
t K ^ lL
lu r u t j
I- UJ ll M
> d
G d to IU
-• D ^ U
(J HH
G R IL
diu ^
U I E IU
dRHj
p □ u ?
R R > 3
r d
g *- □ r
r e u
d t- j u :>
E U E >-
E -I ID
□ — r
u u. u to
■> *—<
: UJ •—
G u ID R
-Id M
HDUJ E
D □ I ~
G to R _J
US ,
E5tE
□ > LL h
U J
G I.
E tO
d
£c
d □
R R
IU u
S S';
d 3 ►
d d
u
R G
to E
U D
r r
□ □
R
: r
r
J D
J □ G
«o d
IU
• d
. E
£&
G
5
u
ta
CJ
LU
& -
LL
D -J
G d I —J d G G
. r id
: -i u
Il d
D LL
G □
O r □ d >
►-« LiJ h Lj h G
u □ —J t*- to h- lu
j d *- d r > d
-I ►- LL □ • •-•
□ □:-■• U. U IjlQmI
dGI dddDdED
Ii. d □ □ U U
J IU U h- d d it
J > R '0 QU'IER
Z H 'I IU U Z 1 I J □ I
IL t j 'D d IU I'J O G r G
r r ii a d
U. hh > U IU j. □
Dr g g d d x □
g d i-i r d » u _j
G ll I d I U R E '£ G I
G . GOG I —J J
U > d N XJJJt to J 1 > J O X
IDiLZuIIIQjaDE □ d Z
J E □ ~ G tO _J to _l d C_< d “1 “1 Z O “• G
r
uj •-
_i
•- Q
u. d
u
R d
•J
U U
d G
d
□ R
(J to
d e
d U
□ r
LL •-*
_i
S£
I R
i U.
U □
e r
_j d
E
> U
d d
□
E U
U I
E h-
I CU 0 J (5 '\1 0 J Z 0J OJ 0 J
© © © © © © © O ©
ij. © *-H
in u*<
0 J CU 0 J
0 J CO rt
it* in in
CU 0 J 0 J
© © ©
in vd r - oc> o- © — oj co 4 - iri •£> r--
ir> in in ir< in d d d d d d 0 d
cu oj " ..
© ©
4 4 4 4 4 4
•DO '? • © »" Ol CO rt IT>
•Xi x» f - n r - p-- r - N
0 J 0 J ilj 0 J 0 J 0 J 0 J '\J
© © © © © © © ©
G
i P N © cr- ©■ — nj oj u'i '£> r- © a. © -• oj co
N f'- N N 00 00 00 00 0j 00 0j 00 Oj Oj 0> <t. 0> O. ij.
1 U OJ OJ CU OJ CU Oj OJ OJ oj oj oj OJ oj CU CU 0J OJ OJ
© © © © © © © © o © © © © © © ©• © © ©
in 0 N
O' o. o .
CU CU OJ
CD o
cu — n ©
.H
rt
© © © © CO
o
rt. CO rt. ©
© rt.
o UJ
Lil © LU LU
©
o
p p p p o
u
© LU o IU
G o
in o
uj l£| © ©
© h_ ©
Ll
n rt. u j u. in
o
co &. G o
Il d*
- -D
~ O CD *D
CU Uj o
rt
© u. o UJ rt.
—
rt x> •£. vD
uj CO
, OJ CO
G »- R 0 j
uj Uj oj lu oj co co in oj cr.
d oj d C'j •£' d uo g
d G CU CO
d G rt CU |
: co (j
CJ OJ o o
r- u_ cj rt. oj rti
© u u
•XJ CU OJ CU Tt co UJ U IU G U G CJ
0 J N G >_• 1
u p © co co co oj oj -x* cr
Cr. u Ll Ll LL U. d ■=> OJ In N Qj 0- d R U LL Ll Ll Ll Ll U. U. U. Ii. Ll cu U0 Oj R u Ll o Oj *t t- d G
•t^^^^’r^ininlnin in in in in in uo in uo in uo uo uo uo ir.< iri •£• d •£< •£« -d *d r- r- r- r - r-- r-.
© © © © © © o © o © c
OjOj^-tfTt^^rJ-rt-rJ-^tf^^^^Ujin
© © © © O © © © © O © © © © © © © © ©
© © O © © © © ©
cr • cu
• X< cr .
J 0J CO U CJ U Ii. G r-- • J G OJ
w w w <_• © © co ^ in a» cr . u. cu in • £■ j. d g © — ’t r- ■» cc> oo co
oj co oo co oo oj co oj co co co co or' co >?• >7- >?■ o* a. it. ix d d d d d d d
d g o © © ©
:• © o © © © .
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
331
COMMON PILOT: Progress Report
BY LARRY KHERIATY and GEORGE GERHOLD
Micropi
2445 N. Nugent
Lummis Island, WA 98262
Increasing interest in using microcomputers as teaching
tools in combination with increasing realization that BASIC is
not a suitable language for most teaching applications has
created a demand for microcomputer implementations of
PILOT. This article is a status report on a number of micro¬
computer implementations of PILOT and a description of the
extended version of PILOT which has been proposed as a
national standard for the language. This extended version is
called COMMON PILOT.
The original version of PILOT (often called CORE PILOT
or PILOT 73) was created at the San Francisco Medical Cen¬
ter. The language was designed to work on Datapoint terminals
in a stand-alone configuration. The simplicity of CORE PILOT
appealed to users who wanted a language for introducing
children to programming. The philosophy behind CORE
PILOT appealed to users who wanted a language free of
assumptions about proper teaching strategies. The latter group
added extensions to CORE PILOT to convert it into a power¬
ful tool for Computer-Assisted Instruction and for other types
of interactive computing with an important dialogue compo¬
nent. Fortunately most of the extensions were influenced by
an extended version written at Western Washington University;
therefore the resulting dialects of PILOT turned out to be
similar in form, but dissimilar in details of syntax. Under these
circumstances standardization seems to be both an achievable
and a worthwhile goal. The National Library of Medicine has
assumed sponsorship of the task. Initially it appeared that
there was a sharp division between the supporters of simplicity
(which seemed to be essential for small machine implementa¬
tions) and the supporters of power (which is essential for
acceptance as a general CAI language). One of our reasons for
attempting a microcomputer implementation of the WWU
extended version of PILOT was to demonstrate that the
division was based on false premises. The microcomputer im¬
plementation, which was done under the sponsorship of
Western Washington University, was so successful that the
resulting version was used as the starting point for a detailed
proposal for the national standard. COMMON PILOT, as
described herein, is a refinement of that original proposal;
the refinements are based on extensive discussions with other
PILOT users and on our experience in preparing a version for
commercial distribution. We anticipate that this version will
be backed by a number of institutions at the standardization
meetings.
At this writing (May 1978) we have completed the system
for a 6800 processor, and we are testing a version which takes
full advantage of the calculator board and the multi-user capa¬
bility of the Southwest Technical Products 6800/2 computer.
This version will deliver COMMON PILOT on a 4 terminal
system. Hardware requirements include a 32K 6800/2 com¬
puter, 4 serial interfaces, a dual floppy disk, a calculator
board, the multi-user board, and 4 CRT’s. As the total cost of
this hardware is about $6000, the system opens the way for
schools to begin using CAI at relatively low cost. Southwest
Technical Products will be distributing systems software for
this version of COMMON PILOT starting in the summer of
1978. The software will function on a single or on multiple-
terminal systems.
In addition we are translating the system software into
8080/Z80 code, and we are testing COMMON PILOT written
in PASCAL. PASCAL source copies will be available by Fall
1978 for $300.
Description of COMMON PILOT
At least two microcomputer versions of PILOT have been
described in the microcomputer journals. These versions
are actually subsets of CORE PILOT. COMMON PILOT
includes numerous features which put it into a different class
from CORE PILOT. Perhaps the most significant feature of
COMMON PILOT is the fact that the PILOT program is inter¬
preted from disk. The system automatically pages the program
into memory. While only a few lines are in a buffer at one
time, there are no restrictions on branching ranges, that is,
branches are not restricted to that portion resident in memory.
As a result there is virtually no limit on the length of the CAI
program. A typical PILOT program to provide one hour of
quality instruction may be 1500-2500 lines long and may
occupy 60K-90K on a disk. Workspace in the memory is
reserved for storage of variables, arrays, and strings. COMMON
PILOT uses floating point variables, one- and two-dimensional
numeric arrays, and varying length character strings (maximum
length 999).
Language Summary
Labels; 1 to 6 characters (labeled line begins with *)
Operation Codes Remarks
PR: option list U — force to uppercase
S — eliminate spaces
E — escape allowed
L — force to lowercase
G — goto allowed
W — clear label table
blank option list leaves prior options
unchanged
R: remark ignored at execution time
T: text type text after substituting current values
for string and numeric variables
: text continuation of previous type
A: accept answer into answer buffer (option¬
ally into numeric and/or string variable)
M: pattern match answer buffer with pattern
332
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 27
J: destination
jump to label, last A: , next M: , or next
PR.
U: label
use subroutine
E:
end subroutine or course
XI: string variable
execute string variable as PILOT instruc¬
tion
FI: record, string
load variable from disk
variable
FO: record, string
write variable onto disk
variable
D: variable (N)
create 1 dimensional array
variable (N,M)
create 2 dimensional array
variable $ (N)
create string variable
C: variable =
assignment
expression
C: /variable edit
text editing of string variable
option
Edit Options:
C — capitalize first letter
U — translate string to uppercase
/xy/ — replace all occurrences of character x by character y
/x/ — remove all occurrences of character x
Match Pattern Symbols:
* — match any single character
% — match space, start, or end
& — match any number of arbitrary characters
! — match one answer or another
Modifiers:
H append to T for no CR/LF (TH:)
J append to M for auto jump to next M if no match
S append to M to allow for some spelling errors
X append to A to override input text editing
Conditioners (append to any op code):
Y execute only if last match was successful
N execute only if last match was unsuccessful
E execute only if error condition raised
C execute only if last conditional was true
n(0-9) execute only if equal to answer counter
Rational Expressions (append to any op code, enclose in
parentheses):
execute only if logical value of expression is true
Execution Time Commands (entered by student in response to
A:):
goto destination — jump to destination
@ text — causes U: SYSX to be executed
Computational Operators and Features:
+ — * / ** !! (string concatenation) & (and) !(or) *- diadics
= < > < > <= >= «- relational
'v (not) — monadics
%A — system variable, answer counter (number of sequen¬
tial uses of same A: instruction)
%B — system variable, answer buffer
ABS, FIX, INT, SGN, RND, SIN, COS, ATN, SQR, EXP
LOG, LN, STR (float to string conversion), FLO (string to
float conversion)
ASC, CHR, LEN, INS (instring)
Subscripts:
X(N), Y(N,N) N = variable or constant, 0 to 999
A$(P) character at position P
A$(P,L) substring, starting at P for length L
It is evident from this summary that COMMON PILOT in¬
cludes numeric and string operators which make it comparable
to a good extended BASIC: random access disk files are sup¬
ported (when handled in the DOS), and the conversational and
pattern-matching capabilities are very powerful. We maintain
that COMMON PILOT contains all the features necessary for
versatile CAI, and that it does not contain unnecessary fea¬
tures. We do anticipate extensions to facilitate graphics since
at present graphics can be handled only by loading control
characters into string variables and displaying them via Type
instructions. A set of graphics commands will emerge from the
standardization meetings. They will take the form of a set of
operators which can be included in the text field of a G: op
code.
PILOT has the unusual history of being a CAI language
which was designed and implemented by authors who were
experienced CAI authors and who used the language to
program CAI materials.* The result in the case of COMMON
PILOT is a language which is powerful enough for program¬
ming sophisticated CAI materials, which is efficient enough for
use on microcomputers, on minicomputers, and on large main¬
frame computers, and which is simple enough for teachers to
master in a short workshop. With our implementations it will
be easy for all CAI users to get access to 100% compatible
systems that are extended enough to deliver high quality CAI.
The SWTP 6800 version provides an inexpensive entry into
CAI for new users. The PASCAL version provides an easy way
to implement COMMON PILOT on larger machines either by
running directly or by coding from PASCAL into machine
language. While the exact configuration needed for the 8080
version is not yet defined—and may depend on vendor support
—it will provide an alternate low-cost entry into CAI. Potential
users desiring a more complete description of COMMON
PILOT may obtain an author’s guide from Micropi for $6.
Micropi also plans to offer courseware written in COMMON
PILOT. We will have a number of courses available by Fall of
1978. It is hoped that the library of courses available will
continually grow as the availability of low-cost hardware
encourages more CAI authors. We also have the facility to do
machine translation from COURSEWRITER II and III and
much of BASIC into COMMON PILOT.
So, if you’re interested in CAI that’s like the big guy’s CAI
but at hobby prices, look into what COMMON PILOT offers.
If you are tempted to invent another version of PILOT, please
let us know what you propose. We’ll transmit them, but not
necessarily advocate them, to the standardization meetings.
It just might not be too late to avoid doing to PILOT what has
been done to BASIC.
* We have observed that programmers who are experienced
with computers but new to COMMON PILOT and CAI often
propose extensions to the language which are of very limited
use in CAI programming.
Editors Note: People’s Computer Company publications have
long been interested in implementations and uses of PILOT.
Articles, programs and listings can be found in the following:
People’s Computer Company Newspaper Vol 5, Nos. 3-5
People’s Computers magazine Vol 5, No. 6, Vol 6, Nos. 1 & 2.
A complete documentation and source listing of Dr. John
Starkweather’s 8080 PILOT can be found in Dr. Dobb’s
Journal Vol 2, Nos. 4 & 5 (April, May, 1977). - TR W.
Number 27
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 47
333
Dr. DoBB'S loURNALof
COMPUTER
(Calisthenics Orthodontia
Running Light Without Overbyte
Number 28 September 1978 Volume 3, Issue 8
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
SOFTWARE
EM8080: An 8080 Emulator for 6800 Systems Gary Gaugler 4
Now you can run 8080 code on a 6800
Lisp for the 6800 Fritz van der Wateren 24
Description of an implementation of this list processing language
FORTH Dump Programs John James 26
Some examples of programming in FORTH
Dumping Northstar Disk Files Titus Purdin 38
Vocal Memory Dump Phil Mork 42
Demonstrating a simple voice output technique
HARDWARE
The Last of the First Aubrey Dahl 20
The last Univac II is laid to rest
Making a New Case for the H-9 Terminal Howard L. Nurse 30
Converting Heath’s terminal to display lower case
A Programmable IC Tester for KIM Joel Swank
33
© David Dameron 1979
INFLATION HITS DR. DOBB’S
A magazine depends on the good will of its readers for
its continued existence. Dr. Dobb’s Journal has been
especially fortunate in having readers who have put up with
irregular deliveries, occasional foot-in-mouth disease and
have yet submitted valuable material out of sheer interest in
the subject and a desire to share their enthusiasm with
others. We count ourselves lucky for knowing such folks.
However, Time and Dow-Jones wait for no man, and the
rising cost of everything is forcing us to increase the price
of Dr. Dobb’s. We have gone on for 214 years without an
increase in the cover price and now find it inevitable if we
are to survive as an independent journal which accepts no
paid advertising. Starting with issue number 29 (October,
1978) the cover price will be $2 per issue and the subscrip¬
tion price will be $15 per year. Until October first, we are
including the opportunity to subscribe or renew your
present subscription at the old price of $12.
While we regret the necessity of a price increase, we
hope that it will enable us to continue to present the kind
of articles and comment which will make personal
computing an interesting and rewarding activity. For this
we can only partially rely on money. The other part of the
equation is the continued confidence and support of you,
our readers and contributors.
— Tom Williams
SOME PRAISE FOR A SUPPLIER
Dear‘Doc’: Received: 78 June8
Just wanted to drop you a line to let you know how much I
enjoy your mag. I think it’s first class. I also think we ought
to thank all of the authors who have so kindly allowed you
(and all of us) to share the fruits of their labors.
Sometimes, we hobbyists are quick to condemn a supplier
for poor service, but slow to praise good service. I want to do
my share to correct this by mentioning a company which has
gone out of its way to help me with an equipment problem.
The company is George Risk Industries, G.R. I. Plaza, Kimball,
Nebraska 69145. They are an OEM vendor of keyboards and
related items, and have several low priced models for the
hobbyist market. I had a problem with my keyboard, and I
wrote them a letter describing the problem. To my surprise,
I received a personal reply within 1 week, including mailing
time. The info was helpful, but did not solve the problem, so
I wrote again. Within about 10 days, I had not only received a
reply, but also a bag of parts which fixed the problem, all at
NO CHARGE. Considering the tales of woe we all read about,
I was most impressed with this service. Along with the ‘fix’,
the company included some other useful info. They are dev¬
eloping applications sheets which show how to interface GRI
keyboards to popular microcomputers. Keep up the good
work.
Regards. 2514 Glendale Ct. NE
Lewis Moseley Conyers, GA 30207
...AND MORE PRAISE
Dear Tom: Received: 78 July 24
I have read for many months now your comments about
the widely varying quality and support offered to the Micro¬
computer fraternity. Once in a while, something unusually
good happens and this is the reason that I want to call it to
your attention. The good guys in this case are KEA-Micro¬
design of Canada, the manufacturers of the Graphic-Add
Board which when added to a P.T. Co VDM turns it into a
device capable of excellent graphics for the extremely modest
sum of $50.00.
I originally purchased Graphic-Add when it first came on
the market and because of my limited software experience
was at first chagrined to find that the software basically was
written for SOL and the SOLOS operating system. I had
neither. What I did have was a Micropolis disk system that
used packed BCD for storage while Solos wanted pure Binary.
I wrote to Ken Anderson and got an immediate response
and a number of helpful suggestions. By the time I was done,
Ken Anderson had written me a conversion program using the
peculiar Assembler Language calls of Micropolis so that I
was able to link Micropolis Basic to Graphic-Add.
I was still glowing with pleasure from the help that I had
received, when to my surprise, Ken Anderson sent me a com¬
plete updated set of software, at no extra charge, with a
wonderful cassette which included a super version of LIFE
with full graphics, a graphics version of Li-Chen Wang’s
Robot Language, and a patch called GAX, which when com¬
bined with P.T. Co’s Basic 5 gives a powerful Basic with full
Graphics Control Commands.
I have really never written letters of praise before. But
when one gets this kind of support and interest from someone
really interested in helping regardless of the miniscule cost
of the purchased item, I figured I had to let you know.
By the way, while I am handing out rare praise, may I
also compliment Micropolis for their support and rapid res¬
ponse to my many and varied questions about their system.
Sincerely yours, 1 Rutlege Road
Raymond M. Glueck Pine Brook, N.J. 07058
FLASH WARNING-SAM 76 CP/M RELEASE
News Release Received: 78 July 31
Forty undescribed but working functions. Particularly
dangerous uncautious execution %xu, etc. /=. Watch Dr.
Dobb’s for descriptions. The source program for the disk
functions as implemented in the CP/M version will be pub¬
lished in Dr. Dobb’s Journal, however copies may be
purchased for the implementation of the moment—no
guarantee that it will match the object code furnished—but
to serve as a model for implementation in other disk systems;
price is $10.00 postpaid; available as a xerox printed copy
or in machine readable form on standard diskette or paper
tape [TDL macro format], SAM76 Inc., Box 257, R.R.l,
Pennington, N.J., 08534.
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 3
337
EM8080: An 8080 Emulator
for 6800 Systems
BY GARY GAUGLER
2276 Beaver Valley Road
Fairborn, OH 45234
If you enjoy your 6800 as much as I do, you rarely spend
much time with thoughts of the 8080 or Z80. Nevertheless,
there always seems to be some program which appears in a
magazine that I would like to try out but can’t since it was
written in 8080 code and won’t work on my 6800. Well
now we can run 8080 code right on our 6800 machine via
“emulation.”
Emulation is a technique whereby the code of the “target”
(the 8080) is executed on a “host” machine (our 6800).
The emulation process executes the target machine code
via software written in the host’s language. So what we have
is a way to run 8080 machine language programs via software
in a 6800 system; we do not have to rush out and buy an
8080. All of this emulation capability is not free; the cost is
loss of speed in emulated code. Code which is run on an
emulator (at least for macroprocessors like we use) will be
slower, much slower, than it would be if run on a machine
for which it was intended. Since fast execution was not a
prime consideration for emulating, just the program’s intended
function, the slow execution time can be tolerated.
The emulator maintains a set of pseudo registers for the
8080. These are actually locations in the 6800 machine’s
RAM such that when a reference is made to a specific 8080
register via an 8080 machine instruction, the RAM location
corresponding to that register is operated on to result in a
RAM contents equal to that in the real 8080 register. One
of the most important registers to emulate is the condition
code register; great care must be taken to ensure that this
emulated register contains valid results for all operations
which might be performed.
The emulator presented here provides a bonus feature:
it can execute 8080 code and in addition, it can do so in a
single step mode. This is nice if you want to try out a routine
you have seen or one which you have written in 8080 code
and would like to observe the program flow step-by-step.
This feature is possible because EM8080 contains two levels
of emulation: a monitor level in which the user interacts with
the emulator and provides instructions to the emulator, and
another level which is the actual emulation function.
EM8080 displays the emulated registers when requested
through the emulator monitor (the RG command), whenever
the emulator stops emulating because it encounters an opcode
it does not emulate, or when it encounters an address which
was specified as being a break address. There are certain
8080 instructions which are not emulated—those which deal
with the parity bit. When an instruction is encountered but
is not emulated by EM8080, emulation ceases and a message
“NOT EMULATED CODE” is displayed along with a register
dump.
The instructions which EM8080 recognizes as monitor
commands are: HP, AB, CB, LO, CR, RU, RG, SO, SF, PC,
EO, EF, EX, control C, and space bar. When the emulator is
first executed, a colon (:) is displayed which indicates that
no emulation is in progress; the emulator is in a monitor mode.
The HP command will print out a summary of the monitor
commands and explanations in case you should need a little
refreshing while emulating. The other commands are:
AB — This command will cause EM8080 to prompt for an
address which will be the breakpoint address. When a
program is being emulated and the address set up by
the AB command is encountered, emulation ceases
and a register dump is performed followed by a return
to the emulator monitor.
CB — This command removes the break address as set by the
AB command.
LO — This command permits the entry of octal data into
memory.
CR — This command clears the emulated registers.
RG — This causes the emulated registers to be displayed.
SO — This command enables single stepping through the
8080 program.
SF — Turns off the single step mode.
PC — This command sets the 8080 program counter (PC)
to a value entered from the keyboard.
EO — This command enables the echoing of characters
when received.
EF — Turns off the echoing of characters (normal mode).
EX — Also control C. Returns to M1KBUG monitor.
RU - Also space bar. Causes the 8080 program to be RUn.
The space bar accomplishes the same function but is
ideally suited to use in the single step mode since
execution of each instruction is initiated via a single
space bar depression.
I/O
The only specific care which must be taken before using
the emulator is in emulating the input character function
from the keyboard. EM8080 may be used with MIKBUG
at 300 baud maximum or with an ACIA type monitor at up
338
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
Install a DPDT or DPST switch as shown. When emulating, throw the
switch closed. When operating the computer normally, be sure that the
switch is open.
to 9600 baud. The input character function is handled via
an IRQ interrupt initiated by the start bit when using
MIKGUB or via the receive data register full flag (RDRF) in an
ACIA. The program listing is written for the MIKBUG monitor
with the necessary modifications noted for use with an ACIA.
Both versions have been tested with the benchmark program
and perform the same.
Fig. 1 shows the hardware changes which must be made to
the MIKBUG interface (the MP-C card with the SWTPC
68 computer). When using an ACIA, connect the IRQ (not
the NMI) pad to the “I” pad on the MP-S serial card.
The emulator was benchmarked on the PALO ALTO Tiny
Basic by Li-Chen Wang which appeared in Dr. Dobb’s Journal,
Vol. 1, No. 4, May, 1976 on page 12. This BASIC runs about
twenty times slower than the same BASIC on an 8080 system.
The emulator was run on an SWTPC using a / I CPU board.
Due to the length of the emulator (about 3K),
arrangements have been made with Computerware in
Encinitas, CA to supply KC cassettes of the emulator and the
benchmark BASIC for $9.95 post paid. Computerware’s
address is: 830 First St., Encinitas, CA 92024.
tr z
*- 3
cn a
< *
u
• o
a o
u_ a
_J <
O 03
> z a z
: M i/i o i/i a o
a a a o •-
o « < a i-
a x < x <
<x UKU JU
3 x < i z a
t-4 O C
3 (Vi Q -4 O >-
• U
KOHOUJ
> 3 3 3 3 >
jaaiQ.cc
«t- z ►- z c
> d d —h a
) O X O X •“*
< o
•- UJ
a z
a a
cn 3
a
uj a
u
►— <
uj a
o IP
cr z a
z o
M I UJ
a a
i < <
u i u
z <_
c <X
a o
1ZK
(Vi •->
OUJ-UN440CL/IO
O^Q-IJ-UOCJOO
00—<—<000000
aaaaaaaoaa> <r
z o
OZh®3
O -« O -T CO
OOuJOJC
IP UJ CD < •—
CD » & X
a <
o o
« a
< <
<r <
l/ll/l Q t-
o < j in
►- u. oxo
uj _j u rvj
o o a - 3 z
a <- o a O »-< a
i/i u n
Z Z O
o o
X X a
<0X0
zoo
O Z
X *-« a
<10 1/1
4- t- O H- u.
Z a <1 Z Z _J
o - _j □ o o a
x a a a x x o
tn z
in <r
*- a
x o
3333333333
OOOOOOOOOO
UJUJUJUJUJUJUJUJUJU-'
O *-< in in
3 < i ax i
crt-oxonj 'i in
— e3Z<x3-<3— o
xac*-cDcaca*-<
o < x x a
a a o ►- x
O CD _J IP
a >
< *-•
x
IP z
hBO
-« o
a o o o
o in <i uj
3 < < <
O O ►— *-<
UJ _J IP o
a a a a a x
OOOOOOr-
Z Z Z Z Z ^ if)
< cd < a: cd < <
x>-<a<aa<<o<<<oa<<uj<xa<aa
HUJiPoiPiPotDi±j*-occujiPomzcoiPt-inip
ipiPccjnjuaHPjucDijuccj-OiPCDai
uj o —< o 'r*> o cd uj oo
< o o< o < ar-o
r- o < -< -< o —■ < m a — C ao<o<ucr
ip «a a n a a <\j pjipo —* a o oivipaipcir
ip>pr-co«7'o-<(vjn>t
OU-UN < 4COIPO
Cf^C*3<J(_Ol_OC
OC^H—<000000
aaaaaacoacc<
o o CM ip co
c o o o o
o o o o o
IP IP IP IP IP
c c
c o
IP IP
cc a
-< -< n
«N«9<CDUHlV409UliiU. -<4 'CMJUliJIl.Hn'CO'Oa
rrr,r, r'r.rjjj -4 -4 -4
ooooooococooooooooooocoooooco
LPIPIPIPIPIPIPIPIPIPIPIPIPIPIPLPIPIPIPIPIPIPIPIPIPIPIPIPIP
Number 28
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 5
339
CD < ►—
< UJ CO
Z _l UJ
UJ U h-
uj in in
x uj cr uj
o o o o o o
UJ UJ UJ UJ UJ UJ
a a a a a a: u
o o
CCUDUX J<U
O O Q
-J _J — Q -< <
u. u. a. o <x a. z
k cd y: a cc ic 3
x < in uj < in a
I O O {/)
o o -j in < x
*-_J<U_:DOXt-U4U.
hju.z>-zzh<ikjo
U.H3U33IOUJ3Q; UJ
' *—xo:ina:Q:»a » o (_> a:
inminininininin z in in in
inxixxxxxx kxoi i
u.OfNjrvjt\jnj(>jc\jrvjrvju»in»yuf\iU'T
JUKt-KKt-HKI-JXHQ.hai-
cr a: 333333 Djq:iu303iu3
o»oooooooou*o»o*o
Z>D~a»-OXXUJ<
oo j jwujoa z a
ujiuuuk cr jute®
DahUJHuj<xQ:><aaQ.
oininzinzccoinoininx
UJ“>»-CD*-CDCD_J")_l“>n">
u in a in
Zb- _J b-
a u a
urn a in Daacrcrcrcrttaaaxxxin
Zb- _J t- CJ J J JJJ JJJJJOZKh
*-• a o cr uji_>ui_juuuijuou_i*— incr
Dorxaaaoraaaaaxaxaxa
oinoinminininininininoinoinox
UJ~>_l“5—>_J—>_J—>
z z
3 3
a a
o O' u. <
a o co
< < < < < r\j u.
in in o in in o o
UJ U O Mil O -O O
or-r^njU-CDOJfvj
®UCO(MJU.^-J Nff 1
CCCCCCUjUjIlU.'
oooooooooo
ininininmininininin
in'Cr^-coo'©'—rurw
44444ininininin
MJ O co uj u. co cc co
coo o >c sec u o cc
—•<r-<i.-uj<o«iooo
ininoin—cinujinujinin
OO'DO'C OUJOUJOOUJ
cof^ivr^c\ji\jOGCija or r-
cDCDu-nvo® <o on® O'
UU.U.UUU.UUUOCC-©
OOOOOOOOCF-«r<^
inininininmininininininin
U. O'
r- cr
o cr
u.o c-.(vjn^-om>o r*-
CC U ODCDCDGOQDCDGDO CD
< < <<<<<<<< <
inir inininininininin in
U.U.U.U.U.U.U.U.U.U.UJCCU.O'
r*-r^irr^-r^r^r^Kr^r^oou.n
in in
4 in
4 r» co cd uuu. ivjn^cru i. win® muu.
—* — --^--i\.(\jMV(\j(Vjnnnnrn
in in in m ininininininininininininininin
r- co o —* n4in®NcDO'oiHwn>tin'CN
f*- CO CC COCOCOaOCCCOCDO'O'O'O'O-O'O'O'
CD U. < <
© < o o
o < o o
in in uj uj
OUJOOl
(E O (T CD I
> o cr a* *
t 4 4 4 4
<<<<<<
o o o o o u
o o o o o o
UJ UJ UJ UJ UJ UJ
CD r- co uj
O ffiOO
o < o <
in m uj in
ininininininininininininininin
h(\jh
OJ CVJ CVI OJ
' o ^ (\j n
- o o o o
i <\j r\j rvj (M
in «o n co O'«
oooooo-
(\l (VJ (M (\J (\J (\J f
< U. CO
O CD U
O < O
uj in uj
in in in
4 in «©
rvj oj (\j
a: z
b- o n*
in — _i
in o
a o uj
c a
a cr »-
uj < z
I X o
ZlflH
o cr *-
x
u in
O o
k uj a
z a in ►
*—5 0: • in
o o *— o uj
a o u. z >
J- l/l z
« u_ a
3 3
* a ►-
O UJ
c ►— cr
_J z
*— u!
o a •
o a •
o o
►- H- >
Z Z Z
0 .5 O X
x a x z
»- o c
z o u
ozx~*zx-*xx
xo * z o »z * *
• XOXX^XOJO
N X I\l
- * z
» o X
n > »—
Z - 3
X » o
\ Q. \ l/l \ < X (_) X UJ X X XI_1XQ.XU.XZXU.VE
ajaDaxacooxa 3zooo>-oi-u.>-oxu.xx z
luxQujjoujujauji/iuaujuiuujuujuujH
* N.xx<ixox_jxi_>XQ:xaxinxinxinxujxujxx
O -J
w 3 Z
vijxaxu.xzxu.xExcr
~ ^ ‘ • u_>-oxu_xxzxt-
"* * ".MX
. o
J o
o -• a
in < a o o
u. x ►- o o u. _j
j m 4 a < j u.
(X < O < CD (X CD
u i a cc <j u <
<i a <x o.
a in a x
CD n CD
x<rauj<a.ujxa
ooxzoxzox
jjur jucc jt
<aoxxxx<<a
oxujzzzzaox
DUCDOCDUHUCDUCrOCDOCDUCDOCCOCDUCDOtDUEOCDDaa
oooooooooooooocoooocjooooooooooinx
UJU-U-U-U-U_U-U-U-U_U.U-U_U-U-U-U.U_U_U.U-U-U-U_U-U.U-U.U_UJ - l - 5
cr in
_J H-
i_> a
ooxooxooin
cwoinuiKiflzi-
ujt jni/iiHix
o rvj m r*-
in m ir in
© © © ©
in in in in
z m
o z
X X
o co
CD O O
© « © cr < —* 4 oj ©
inirocino©©©
U1 «— \T1 1.1 li I
occ<rviir<(ViU-'C
«IOO(\J4MO'CCO
irin'EZ'C'C'C'CiD
C CO© c oco©
ininininininininin
® 0'o-H(vjn4iT'0
NMiatCC®!
cc o
O 4
© —
in in
'O^-r^cooccDcoo'OUJ
cc<x(\jooocf\jar^
u.^nin>OMcoo'CDo
©©©©©©ococ
inirinininininininin
®0'o-H(\in4in®N
CCCOO'O'O'O'O'O'O'O'
®<-onoucDn-oj©(vjon-OMn-in^in^ino<© ouj
4in4in4in4in4iririninininirininir. iT4in 4ir4ujin< trr^
©0(\J4'OCO<OUJ©('J4'OCO<OliJ©(VJ4'ncD<OUJ©fVJ4'ECOCOCD
accococccccaaccoo' 00 -o-ooo<<i<i<i<j<i<<cc(rcr:crcrcrcr
OOOOOOCOOOOOOOOOOOOCOOOOOOOOO©©©
ininininininininminininirininininininininininininininininininin
0'O'-(\jn4in'0N®0'OH(vir)4in®N®0'OM(\n*)4ji®N®0'©
0'OOOOOOOOOO-<«-<-<-.rH rt ^^^(\j(\j(\j|\j(\jivjM(VJf\J(Vjn
cr c
o ©
in in
cr n uj n < a) O'
o M M 4 O © O
© <T O O <1 O <
in m uj uj in in in
rvj(\iincocDuJ-*4r-
GUUUUUCCC
©ocooocoo
ininininininininin
Page 6
340
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
Q.
>-
< a z
H- O «-*
< o
cz <j c;
z *- o
o —
—' X t-
►- u •-
u z a
3 <*
a a
in
■ cc
o
UJ (/) OJ ►
a in
u in in (
lu
I- uj s
uj in ~
o Jt-
-• X X Q
ir • * z
x o x o uj
< X
—< X
-• n k o
H- H- * U
a * ouj
s (via <r x 4) o rsj 't u 'C © rvj >j x >o o ru -r .© 13 x «n
3aoioi/iohHhHiHj-t(.(Ma.('ihi\jifli\ji-nin nznhiii't iin-jt-
’ion3noninnunikin<ninnon3noninniijn2nuniniiJOiiJ( r )uj3mn
ja. 03 oaocrocrozooocroa.oo(_>aocrozo*-'oz<j(rzazozoLOct
awu< <n
X ZUJKKX
i_> cd o in in ~>
D<auo<<K<a
O O X Z UJ h O D h X
uj juiroin jjin-)
z)<o_j<xx<aa
0(TZinKODD<I
uj»-<<in_j_i_jH--)
3XCDCDCDCDCDCDOCCDGGCDCDCDCDU)CDCDCDCDCDCCCOCDCDCDCDCDCDCDCDCDCCCCCOCDCDCDCDCCCrCD
OQOOOOOOOOOOOOOCJOQOOOOOOOOQOQOOOQOOQOOOOOO
^lLaU.lL.lLU.U.lL.U.U.U.Ii.li.U.lLU.U.U.Ii.U.U.U.U.L.U.U.U.U.U.U.U.U.U.U.U.Ii.U.U.U.U.U.
CO < U O o OJ
U U U U O C
~ ~ — (\i Pu
in in in in in in
-« ru m ^ in >0
O' O' O' O' O' &
(\J (VI (VJ (VJ (VJ (V
ix cr r*-
4 <\jo<sor>
in c o in o in o in
vC^'0<n-v£)Ljr-uj
acci\j-jcc<u<ih-
cococDOu.oninGo<
O C C © C
(\J(\Jf\j(V (\j(Vj(\jOo(\J(\j
ininininininininmin
o^run^in'Or^-cocr
000000000c
CD u. 'C
nj (Vi cd
(VI (V, o <1
in m o m
ooujo-«4r^a-uo
(vrvrvrvrvfvn.
(Vj(VJ(Vj(Vl(V(Vi(Vj(VJ(VJ(V
inininininininininin
— mi*) 4 in>OMoa o
mmi’immnmmom
iL.<in<r'00(n<vjno^oD(vir**^(vir^«xocoujo<(vj<r:oDa'co<cDo(vjcD<cD(v:(rD'0(vj(r
<u.ivjnoo-J4ir«(vjuoMin^(n 4 .Hi 1 ji 1 .Din-jiruHiri 1 .u^-jukuauD^-ju
(vj<vj«tr)^(vj^r>(vjn^(vj^r)^r)(vj(vj^r^nrvj^r)(vj(vj^r*-m(vj^r)(vj(vj(vif r )(vi(vj^n(vj
inininininininininmininininininininininininininininininininininininininininininin
u.A.-HninMMBQu.-Hnins^cDQu.^ninNa'CDQu.-ninMrcDQu.-'ninMJ'CDOu.
(vivjnnnrinnoo^^ 4 4 ^^•^«tinininininininin'C'C>o<x;»c»c*o*or^r>-r-r^h-r^r^N
(vtvj(vj(vj(vj(vi(vj(vj(vj(vj<vj<vj(vj(vj(vj(vj('j(vj('j(\j(\j(vj('j(v;(v(vi(vj(vj(v.'(vjrvjrvj(v(vj(vj(vrvj(vj(v.(\j(vi(v
ininininininininininininininininininininininmininininininininininininininininininin
ivin>tin<£>r-coo'o^(vjm>tin>or-coCT'0^ojm>tin'Or^ooa'o-.(vin>»in'nr^coa'o-H(\jm
rvjN(vi(virvj(viiM(\jr)nnnmnr»mnr)>t>t>t>t->j>t>t^>t>tininininininininininsOvO'£)«c
nnnnnnnnnnnnnnnnnnnonnnnnnnnnnnnnnnrinnnnni’i
z z II-
cr < 4 >
3 a. oc
h- u. o
UJhQOH
cr uj a in
uj ►- a —
O Z 3
ZhUKK
< X UJ UJ UJ
cr x © o
z UJ Ul
o
UJ X
X <
c z
O Ul
l_> X
UJ
uj a
> o
< z
z <
o z z
— c —
Z Q
O _l Ul
*-• UJ 0
cr
4 u 3
z o Ul
Humu
h- u> a
in a a 3
Ul 3 o o
oouin
* x
• m o
1 <
• x cr
in <-« in o in — in
UJ UJ UJ UJ
H- II >- II >- II >-
o x o a. o
X X Ul
o o cr
> 0 >- x u
I- Uj I- Ul a
cr x 3
> > o
a 11 cr 11 in
o o
iinxwh
UJ UJ Ul UJ Ul
X >- X >- o
z
o
•— 4
>- >- o
U < UJ
3 o cr
cr
H- UJ Ul
in u o
z a a
•-33
o o
o in in
a 4 »-
Qhlfla
O 4 •-« UJ
4 o o cr
uj x
> >- cr 3
a cr z
c o c
X X >- o
x_iin»-Kt-.»-
ui < uj ui ui o UJ
x x >- o o a o
o *■*
in < cr
X 1- o u
U < Q U J
a. o 4 a a:
* a n uj u
j in o x o
• •- a * a.
« uj o o
o o m
o win
a * in
©o-*o-*o©©
UU-4OC0-«O
*«o*i_)»ucr
• oc * cr
ui © in o in r
awi/ixoauiN
#*i/)iroxin*i
J- * O P- ♦ H • Z
troo** cr © uj
O 4 XuJO
ox * cc o
Q “) I O # O
3 x a a x a
o c in in k 1
uj 3 3 3 in 3
)H << 4 < < < 4 <4 <4 < <
C ►-
ox<<cnxxx<ocrcr(r<xo<<OQ.oaoaoQ.
CDQQI-4ZKI-[DZinininhCEZl-CDZIUJlUJlUJ7
)ajjini->-<ini/ii-<jjjini'4ini-4uccu(ru(D3
c *-
in i
> z o
- *-« H-
3 0.
C5 X
3 a
O X
3 a.
O X
<< < << 4 4 CD 4 4 <<CD
Dx<aoao<a.uju<44aujU44a
OOQIUJXUIQXZUJI-QQIZUJI-I-X
ujjJUCDutrjuiroinjjucDOinin 3
3 a. o x 4 x 4
o x uj o o o o
Ul U CD J J J J
^ Ul
00 f"
< ©
in uj
N U CD
4 CD O
© 4 ©
uj in in
in in in in in in
co a- ©
— rvj
rvj rvj rvj
u o
CC CD
4 <
in in
o
© ©
> 00 © IT
r^-
o
UJ
- cvn
(Vi (Vi rvj
(VJ (VJ (VJ
ui'On-'f>oouur»4444r^( fc 4r^N4^r^^n-
u«cc—•ouu-—'Cc>t>r^(r~cocc^cccc(Vjoc(v
rvjinh><aDuu.rvjr>in<o^coGDouj^(vj^^>oo<
eca.ccncc(tao‘ffo(M^affO‘a<<<<44
inininininininininininininininininininininininmin in in in in in in inininininininininininininininininininin in in in in in in in
in'OM»^o^('in^in'OM®(ro-H(vjn4ir>ON®a'
(vj(vj(vjivj(vinnnnnnnnnn44'44 4 >t >t 4 >t
(\j(vj(vj(vj(vj(vi(vj(vj(\j(vj(virvj(\j(vjrvjrvj(\j(vjrvi(vjfvirvj(vj(vi(vi
in © in © © in «
( N -o >0 vO 4 N r
n uj cr cc d 4 cr 1
..I'OaocDOUor
: c o c c o c u 1
< (3 U <
OC CD 4 CD
4 CO 4 04 4
in -h in © in m
0 —« (\J
in in in
(VJ (VJ (VI
in
in in
(VI (VJ
r- cd
in in
(VJ (VJ
© —•
vO ■£)
(VJ (VJ
r>
so >0
(VJ (VJ
l/l'CN
«© © <3
(VJ (VJ (VI
CO O' O *+ (VJ (3
-OONNNN
(VJ (VJ (VI (VJ (VJ (VJ
4 in o sco o o
n- r- r*- r*- n- n- 00
(VJ (VJ (VJ (VJ (VJ (VJ (VJ
-• (VJ
00 CD
(VJ (Vl
-t in «o m» o> o
co cc co co co co o
(VJ (VJ (VJ (VJ (Vl (VJ (VJ
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 7
341
3 I
o
a
UJ
z
3
o
Ui UJ
o o
o
CO
o
CC
II
¥
O
I/)
e
o
CO
o
ao
o
X
II
sc
o
<
t—
X
©
©
co
®
z
a
3
h-
Lkl
Ct
©
CO
o
®
II
*
O
<
h-
tn
o
o
®
®
UJ
*
a
x
<
o
3 <
X H-
UJ 1/1
z *
-H <
3 X
3 3
< a
*-< a.
o UJ
o
0.
z
UJ
z
o x * < * a
a * uj * uj z
UJ h Z O 2 UJ
it I—
h- to
to X
X UJ
♦
o o *
Q. CL SC H-
* • Q H- IO
UJ UJ z to X
Z Z UJ * X UJ
* O Q H-
i- z a. < to
lO ►— *0>-H-
x to uj a ct z
UJIZUJOH
o -h rvj
o < > >-
u >- a: >- x
* uj u u u u
< < < <
< < <
<<<!<<<<
3 < _J < CL 3QCtOtOtO<ICXX<<< <CL
Dl- Dhl OtflhQUlQWOWOOhOKI
0.100.(0”) 33X3030.30.33X3103
3 to to to <
ck oujq:
UJ to J o CD
3IOtOlO<X<X
OhDUJOtOQlO
ujto_jQ_iaja
< 3 3 3 a: < a. 3
O tO tO tO 3 ►— X O
J < < < U tfl ”) UJ
10IOI03<3<<
KOUJDI-DhQ:
ifl3oaioatoai
Diotfltoxxaa
OZt-OOKtfll
u)Mio33toan
3 < ►“ UJ H- UJ lO
a o x z x z
UJ 3 H CC H tE tr
o <
«x to
3
a.
CO
3
CL
to
a
UJ
a
o
z
UJ
o
z
UJ
« n
>■ >
a a
a o
© n
© to
— n- o uj
< O 00 CE CD
n < < < <
to in in to to
u o UJ '
CD CD cc r-
<>-«<© <i n
to © to © io to
fw
o CD
< <
to to
—* N- U O <
OX CD O CD
<X «I < <3 «x
to to to IO IO
o uj - *■« r*>
II CD n o or
< <* n <3 «j
to to to to to
UJ
CD
<
to
N- O 3 O'
00 O CD CD ©
< < < <j n cc
to to to to © to
® o U
CD UJ O
< < >c < o
to to © to ©
®
CD
UJ <
o to
(\jr*-(\jr»uj ou.U4 < 0 <C< 0 <CUJ< 0 N< 0 NUI
n < n < N* CDCCCDf r )CDf r )CDf r )U<CD«X CON*
U.UJ40
CD CD &) (Vi
U.UJ4<O<O<O<O<OCC00(OU.MiJ
iirnanffncc44'jNCDN
L.UJ4(\JN(VJN©
xxnnxmxoj
— 4 U U UJ u o u.
n cd a u u cd t-
OQOOOO 4 N-
ccr^(VJN*(Vin ®co
UJ U CVJ 4
©©•—•»-<>—•
o d n n co
to to to to io
r^r^<o©«^^io®a>uuj-Hfo<o
l Hi«>Hn(Vj(\,(v.(Vi(\i(Vi(Vi(Vir r n to
nonnnnnnnnnnonn
lOlOlOlOlOlOlOlOlOtOlOlOlOlOLO
O' O' o u o
r r ro r. 4
n r, m n n
to to to in to
cvjf\jx®o>oo©^4X®r^
4444444xxxxxx
nnnn cr r> n m n n n co n
totoioioiriotoioiototoioio
<0 OOnONCOCDUU.
to to <0<C<C<0<0<0<0<0<0
nn nnnnnnnnci
tom lotoioioioioioioio
^^rvjto®coujo
r^r^N-r^N-r^r-®
n ci w o Pi ri o ci
toioioioioiototo
CICIOO 1 CCUJO
ct a cc cc ® ® O'
Cl Cl Cl O Cl O Cl
to to to to 10 to IO
*-• n
a O'
n ri
to to
® o< © ^ n^i/i< 0 N® 0 'Ort(\jn^i 0 ' 0 N
C1C1C1.J ^ 4444444XXXXXXXX
o< o rvj m
to ® ® -C 'C
4 4 4 4 4
i0®r^®0'o^(\jn^-i0'0N-®0'
<0<0<0<0<OSNNNNNSNNN
444444444444444
^ryci-jio-csooo'
®®®co®®®®®
444444444
<vj r> 4 to ®
O' ^ O' O' O'
4 4 4 4 4 4
N- ® Oh(\jC)
O' o> o © © o
4 4 IO IO IO IO
<f to <0 ® O'
© o © o ©
to to IO to LO
o
a
u
INI
o
z
o
X
UJ
INI
3
Q
O
u
a
UJ
n ® o tvj n 4 I <o o tvi n 4 ®
lOXlOX Zl0NOl<0O<0l/)<0NNNNNMNh
nujnujujni/inoncinocit/icincinnujcii/i
ozozzoaoaoooaoaooooozoa:
z
o
f- < < 4 < <
>-• N-QN-Q^-Ql-Ql— Q|—
Q 3Z3Z3Z3Z3Z3QH-
z xujcrujcrujaujcrujcKZuj
O 3 3 3 3 3 3 3 3 3 3 3 UJ a
O
O
to -<
X < o
U X N- U 3
3 3 4 3 3 0
a z o a. *- z
* O « CL O I 3
♦ ♦
Z to 4 CD
ici- OX X
►-to O 3 to IO X
to X 0X3 3 •
*X3 o» a x©
♦
(O CD
-• tH 0 3
X 3 I— lO 0 3 3
Z IO X 0X3
© 3 0X3 0*0.
GDCCCDCDCDCDCDaOaD(EGDCDaDGDOOCDanCDCDaOCDCDCD
ooooooooooooooooooooooo
UUUUUUUUUUU3UUUUUUU3UUU
«(CI\J[rCDUMj.<(J'<<DlO(VjClNQ4UJ(DlillVJ
3UOOO®4XUt\J®©ON-403('J®©ON-4
n(Mn(ViM"}n(\j(\j^<j^(v^r)Mn^^4W<jn
u^®u)inirio®ir>i/ii/iinu)i/iioioioioioioioiototo
Hni/INO'COQU.HCllONO'CDOU.-iCllOMMllO
®®®cc®ccccaaoo'0'0'0'0'0'<<4<<<<
cvjcvjcvrvjcvcvcvjojtvjcvjrvicvjcvjcv.rsjrvjcvjfvjcvcvjcvicvcvj
loioioioioioioioiotoioioinioioioioioioioioioio
4l0®N®0'©*-*f'Jf*)4‘l0®N®0*O«-*{Vjn4l0®
'O'O'O'O<O<ONNNNNNNNNN®®00®®(I)(C
connnnnnnnnnnnncnnnnnnrjnr)
o
3 4 0 4 0
Z Z X 3 X O
X CC CD CC CD cr
3
to 4 3 4 a X
O X X X X X X
X CD X CD CD 3 3
3 x x x a o x
OlOQtOUlZ x
3 3 3 3 3 •-* 3
X XXX4444
X XXX
310(0104X404414
OhOUJQDhZI- Cl/O
3®3033tO*-<(03X3
IX 3t0t0l04X4U<
IO X 0>— Q300H-ZN-
X 3 3 10 3033I/)h(0
3
X o o
© —•
n n
* * ♦ o o
o
rvj
n
o
o
m
n
o
o o a n-
® z 3
O C13X
O 0 3 3
X
3
z
4
I
to
3
X
X
o
X
® ©
N- ®
NI\lC)liJlL<ir'CNMC10Cl
_^,_ooococooir:io
X ® 3 X O ®
© ® N- ODN
© < © © 4 n
IT IO 3 IO IO IO
-« N- 4 U
OX X 4
4 4 4 4
to X X to
CVJ to
u u
x r\j o o
to to o o
^ N-
N- OX
n < c
x xx
4 u ro ©
x < -i
<t <i m m
xxx x
®0N“04©X0<0X33 030003
l\j(\J(V(VM\;(\J(V(VJ(VJl\J(VNN X <J CC X 0- h-
334<03N-ON-vC<Cv£)vt)UJ 334®3N-ON-
aiEi'ikUii.irL^^^cis xxcouuuxu
b.HClXMMDOli.HC)XCD
4 aaacr xxxxoooo
<\JOj(\Jt\J(VJ(\J(Vj(\i(\jC'J(Vj(Vj(\j
xxxxxxxxxxxxx
CD CD 3 <J N 4
o o o o o c c
CVJ <Vl (Vj CVI CVJ CVJ CVJ
X X X X X X X
00©r)4f^403-*n4-
OC3UUU.U3U.UUU
CVJCVlCVJCVjCVjCVjCVJCVjCVJCVjfVjCVJ
xxxxxxxxxxxx
<Of^ 4400 h^c.<(J)
uu uuuococoo
cvj cvj NNftjcicicinnci
XX xxxxxxxxx
®0'o^t\ir)4X
®® 0 '^ 0 ' 0 ' 0 ' 0 '
OOCIOCICICICI
®N®0'©H(\JO
O'O'O'O'OO©©
X <C S CD O' C h
© © © © © ^ ^
4 4 4 4 4 4 4
n4l/'<0N®0<OHftjO4
—— ^CVJCVJCVJCVIOJ
444444444444
X® ®O s O»-«('JI34X®
cvj cvj (Mf'jmnnnnnn
44 444444444
Page 8
342
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
z
O < 0 < 0 <<J<X 0 < 0 <
•-* Q.QQ.QQ.OQ.QQ.QQ.
H I2I2I2ZZI ZI
»-• DUJJUJjUJ^UJJliJD
Q
Z
o
o
Z (/)< 0 < 0 <Lu<_l<»—'
o oaoaujazaaorz
mcrcrmfr. rrnrmrrrrm
cl o z
O Z J>
* a uj
^ ct a. a
o <n a: r
UJ
kx o o a. o
m » o o o z
*-• o * uj < Q. UJ
aoj<<<o:a
I/ICOQ hhl/ll
CC<UJ»-l/)in~>“)
COCO O O O
•£• a ®> O ■£> QvO Q 'O O OvOO OsO Q
X<ZKXZX<ZXKZX<K zx<xzxxz
n • uj n • uj f*j » uj r*} » UJ n >- • uj m >- uj m • uj
a o<atr<ao<a o < o: o o: < a o < < a a <
u'QQ'i/iDai/urawzauizcai/izacn/izQ:
CD<CECD(AlCCCCl/'£rCD<CDa;H-'UJ<t’Cr*-«OCDCCOCD
o _j < d < c < < a
coazozcri-r
uj <r »-< _j < < 1/5 “>
(MDOu.^mnNO'CDO u_ u. cu in co co uj « ru
<v(\j<v. rv. <v r; r> r, r r, 4 4
<'4-4-4'4^^«4«4>4>4 -4 >4 >4 >4 >4 >4 >4 <4 >4
inininininininininmin in in in in in in in in in
iD'ON®ao^(\jn4in'CNcc o —< rvj n in ® ^ ® O'
cDODcoooooo'O'O'a'O'O'O'O'a' 0000 00000
inininininminininininminin « >0 <c \o ® ® ® >0 >0
»o in < co
<r cd < r*-
< < n n
in in in in
mmr-r^cocouj'-*
>4*4-4>4«4>4>4>4
inininininininin
^Mn4in®Nffl
\C-C'C>sC'C'C'C~D
UJ UJ
njocoor^>£5o^oocc<<orM^-<ocr'CCon
ujoujooujocujoocoinocoinooaroo
C0'OCOC0(\JOO-4OOOCCO0O<OC2—«C
ocuj<v-ocuj<\jccuj<\iOCUj<'JOcn‘U.’<'Jcrf^u. | <\joDu.<'j
4^)®<OUJOM4'0®<OUJ'<ninN<0liJO(Vj
iriniriririr'C'f'C'C»c>£-»c< l cr^r^r-^-N-r^r-£ca
44444444444444444444444
inininininininirininininininininininininininin
o — njri4-in»or^cco'o^<vfn^in>cr^ooo'o^r\.'
nnnnnnnn( r )444
'C>0>C£I4)'C'04)»0'0XIX3-CX)^4)4)'04)'£ I X)'0'0
<cc
<\j rvjtvj
o 00
o 00
O'r^'4'O'JCcr^uj
r- occ ou. - cc n
OOn4<OQOCDOL.
0 o o-a o o oa 0
«4>4>44>4'4>44>4
in in in in in in in in in
o^(\jn 4 in®N®
ininininininininin
vC»C'C'£)'C'C'C'C'C
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 9
343
a
QC. O
at uj
o at
z a
»- u
o z
a
a
<
u
c
z
o
in
a
UJ
in
o
UJ
a.
cr
u
o
in
a:
UJ
h-
in
o
ui
cr
UJ
>
o
— rvjncxaar- cm 3 cr
•f ^ ^ HU 1 - -f IQJ1 J1U
ooo«£uj>ouj< OO.Z
UUO*-OXOZQUO*-
cr cr n- -• i\j n a a z r*~
o~*mr z z z i ju-o -o
uj>oujooozujoo
ozozouo*-ooo
INNNSNSS Q Q
UJOOOOOOO oo
ZUOUUUOO OO
< in o
X O UJ cz
U UJ X U.O o oo
za* xr o -< z oz
•— » O * UJ * *— UJ UJ
<j in cd in <j
a o oc o cr ^
QQUUJ>< oouxuia^xa. Q
o o uj cr * z o Q- • cr a :> • o z
ooo*o*-*aujo*oroauj
cc
cr
ox X •-*
Q. * * >
uj o I o i
x o
• z
x o
< <
< CD CD < <X
< <
CD < < CD
CD CD
crcDcrcDcrcEaccLCDCDcDcc
oooooooooooo
U.U.U.U.U.U.U.U.U.U.U.U.
CCCCaDCCODCECDCCCrCD
oooooooooo
UUUUUUUUUU
cccrccacrcrcrxcc o <
OOOOOOOOO UJ o
U.U.U.U.U.U.U.U.U. O _J
<XO<JO<COO<ICL
*-ozazozujzt-x
in_j*-*»-<_j<cr>—m3
u<<xu<ux<x<<<ao. x < x < <
ujoi-oujauioooot-Kifli o o o ►- cr
o _j in j o cd o j _j _j _j in in 3 3 _j _j _i in cd
-4 cr
M o
o z
o ►-
< CD
cr cr
o o
z z
o
cr
o
z
<
in cr cr z cr
m o i_ r*- •-*
O UJ UJ o >
o o o ox
> >
X X
z
z
o
o
4
Z
o
o
•—u.xu.UjU.ujcrz<V3u.ujUj4cc:ujCMu_uj4<cr(\ju-Oucrcrz
uj<U'Dccar^o>Jo — 'DcccT'croooO'CcocrcT'Oira— vCxct-<
< < O' u.
cd cr r- <
< < x < o
in it in in o
z
CD
UJ < _
U. X © ©
Z CD
CD M
< r*,
in in
< < oo u. <
CD CD O < CD
< < IT < OU <
in in in in o o in
u. u < o <
CD < CD < <
< © < < in © n
in © in in in © in
co u. 3
N ID ID
n < © < © uj
in in o in o uj
3
CD
< © 3
in o cd
zzxxxxzruzzzxxxzrvtn4xxxxzrvz<rzxxxz
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
<zr-uior-4Z4r'-or<‘Uj < zf v -uj<o<ujzujzf , '-r'-ouj uj z uj n- ©
Mrac<octtu.L(i->jctN n-cccrcjZfMMU.UJOCccnujcDr'- u. uj u. u. cm
UJ o ©
U. Z CVJ
ujoi\J4'Ca)<uujo(\J4
M'lnrrrrnr 4 4 4
ininininininininininmin
inininminininininininin
<3CD<OUJO(\J4'OCI)
4 -4 >4 4 4 in ir in it in
inininininirinininin
inininininminininin
<uujorvj4'Cco< ou.
xxxzzzzzz cz
ininininininininin in ir
inminininmininin m in
cmxx<cdoocm4Xx
r'-r-r-f^-MMxxaaa
inmininininininininin
ininminininininininin
H UJ 4 S ^CDUJxn^C^OUJ'H
a,icM70'0'(M><<<<<<cr
in. ininmininininininininininin
inininmirinininininininininin
4 MM) UJ
cd cr cd a a:
in in in in in
in in in in in
© o 3 in
o o o o
in in in in
in in in in
4XZMxcr©e-<cM34XZMx
333333444444444
a-o - (\j n 4 in-c md o o « i\j n
4xxxxxxxxxxzzzz
>4 ZMxao—« cm34Xzmx
Z ZZZZMMMMMMMMM
o«(\jri4i/i'ONCD»o^(\jn4 z m x cr ©
CDCDCDttlCOCDajCDCDO'O'O'Oa O O O O O
r- r*- m r*- x
cvj 3 4 in
o © o ©
CO CD CO CD
UJ
a
O > O
•— _J <
*- z
o o uj ;
3 _i c
a ccd*
f- O <
inoi-
z
— a a
© z o
© x < u
in
n uj m cm
x in
z u. in in
c UJ
O Z UJ
3 < O
a a o
•- CD o
in
z c o
— z
o
o h- o z
J J z o
* 3 O UJ •
• co a o o
3
uj in
a z
O •-*
O CM O
O © O
< o <
(MOO
o O o
X X O X o
• o o z
o<o < © < a uj
O O X M 3
o a * o z
<1 I.J O 13 lil
< X
ox UJ
© © O X
OHiMnao: in rvjmacrirr- >-• m 3 cr cr cr m
OOOOOU—*© rQ-*—<00—•-‘X'MMrMOO'-'fM
000©/UJ>OliJ<l ©©ZUJ^OUJOOO^Ul^ o
. - CM 3 X a X m
fMZomnoo—«nx
< < CD X < <
< <
a<_j<io<o<<-j<a<
caoaxzozcc>-3croor
xcDXi-a<j<<inaxxcD
a < < x x
in o m m x
3 _i in 3 3
<
M M f*-
3 O ©
© © ©
O O O
CM
©
O
< x < < a
o o M x x
J J OUT 3
CM O
Z ©
© ©
O O
3 <
c cr
uj t-
UJ
< < < < o
o
o_j<x<oaxa
zini-oo < o x
<<l/)JJKI-J3
m
UJ
►— <
©
©
3 cc cd cr cr cd cr cr
caoooooo
UJUUUUUUU
CDtCDCCCCirirCECD
OOOOOOOOO
UUUUUUUUU
ccffitcaDtuEccir
OOOOOOOOO
U.U.U.U.U.U.U.U.U.
X X X X X X X X
oooooooo
uuuuuuuu
X
X
©
X X
a x
< o <
X UJ X
X X
X X
—« Ui < <
© U. X X
X
X
< < X
O X U'
O X ^ CC
UJ X<M
Z © < 3 3
X © X X X
XU X
xx r—
<<003
X X O U X
O' o z
UJ Uj X
4 4 < © ©
XXX © o
I > "' — ‘Z‘ —, ULljUjMCC Z<UUUU<crCT'OCCUUUC , CCZ' — 'CTUU uj cm X
COXUJZXC7'<U'4ZUZCCCrXUCXUZ®0'0'0'4M©ZXa'<0
ZoO'r*-Z4Z4CDM(\JOZo
MlNOr (t(JU.'-r3CHMV
O Z M o Ui
cr < x x m
Z UJ N c UJ
x u < cm r-
r- 4 X M UJ Z z UJ UJ
— X-4XOX C Uj Z
'JZZXXXX-4fMZZXXXX'4fMXZXXXX'4rMZZXXXX'4fM
xxxxxxxxxxxxxxxxxxnxxxxxxxxxxxxxx
CMXM<XOUI©3'4MX
<0<<<<<XXXCLX
>J44'J4'J^44-J44
xxxxxxxxxxxx
< O U. IM 4 N < O©
xx cruooc oc
>J'4 4*4
XX X X X X X XX
3 X M <4XOUJ«4
C C C CCOOCU.U
*44-4 4444444
XXX xxxxxxx
M X < OOUJO(M4ZX<UUJ©CM4ZX<OUJOCM*4ZX<OUJO(M4ZX<0
uu-'u. UjU-U.uu.uuuuu.uocc ccccc<Hnr.^^p.r-^(v J (V(va(\j(\ J (\ 1
4-4 4 44444444444XXXXXXXXXXX XXXXXXXXXXXX
XXX xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
•—<(M34XZMXO'©'-<CM3>4
Z Z Z Z Z Z Z Z Z M M M M M
z z z z z z z z z z z z z z
ZMC^O
r^r-MMcr
z z z z z
CM 3 4 X Z X O'
X X X X X XX
z z z z z z z
O — (M34XZMX
OOOOOOO'O'O
zzzzzzzzz
O « (\) 3 4 XZMX0'O'^(M34XZMX O -h (\j 3 4XZMXC7' O >h AJ 3
0000000000-HHHHHHHHH-.(M(M(M(M(M(Mt\JlM(\J(ll3333
Page 10
344
Or. Oobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
a
UJ
t—
z
to
CL
<
a
o
UJ
a
o
o
<3
o
cd x ^
cr ujt- a) i- h oo oo
XO (Tin*-«l/>l/)OuJUJO o O UJ uJ Q o
• 2 ozx z zz a oiz z zcrcrz 2
• IOH-. * < UJ _J UJ UJ UJ CD CD UJ a O UJ X I UJ CD CD UJ Q OUJ I
* * in
K H O
Q l/l (/)OUJXXXX
zz z z a • * • •
x uj uj uj uj * oom -t
O O X
o o -
* uj uj <
oj
X 3 O O
•• z O <
in uj o o
♦ in
^ a: mo
o a o uj
< < O' < a
oo*o*
3xo< z> a x a. x x x a x
oouja o i/i t- z o z ►- x o
uj j o cd uj -> in ~) jmi/o _j
x x a. x x x a xxxa. x x
z ►- * oz»-x O Z *- X OUJ
*-* in ”> _j •-< m j m i/) _j q
x a. xxxa. xxxaxxxa.
*- X O UJt- Z CUJhIOUJKI
in - ) join - ) jcim joon
CD<X<CD<CD <<<<<<<
x<<o<jii<o<<j<j<q.
oooooinina zap-Ok-Ok-x
jjj<<aat-<oina.ina.in-)
CD CD CD CD CD
<<<J<<<<X
oi-ujt-ctoao
jinotncDjcDj
m *-< n n n m r>
o o o oj ^ ^
o o o o o o o
0<JCJOO<J<J
<n or^r*- f- r-oo u. u. ® —• —• co n m ® u.
DC UJCDUJ CD CDN < < N CD (UN CD (BN <
<oo ®<® <x < m < < n < « m < <sr> <
mo< in in in in in in in in in in mm m mm in
m m m cr ^ cvj
m m r*- o o o
e c o < < <
o o o o o o
u.® -h —• ® ® o ® r*- r^®u. voo ®
<N CD CDS CD 1! h- CD CD N < CDCO n-
<cn < <a m < < ® < < n < o o m < •-<<< < mn
mm m mm m minin mmmoooo c m in o om
UJ < o
U. ® <\J
OU.UJ UJ 00 U. UJ UJ ® U- UJ
a: u. r*- u. o u_ t" u. o u. h-
UJ ® U. UJ UJ ® U. UJ UJ O' U- UJ
u. o u. K u. o u. u. o u. n-
UJ O' u. UJ UJO'U-UJUJO'U-UJUJ
l o u. n u_ o u. r*- u. o u. o
oomO'Oh-r*- <<r^t\jr*><\jr^uj
uj<<uinnocDccccn<n<N
n- < o uj uj —• < n < co uj *-« < in ® m
OOOO OOCC CCCC U. b. U UJ UJ
mmmm m in m m in in in in m in in in m
mmmm mmmm mmmm mmmm m
uj u. cvj m ® o o u. <vj n o 0000 nor>-
U. U_U_ U.UU.U. U.OOO o CO
m m m mmmm in «c <c ® -c o o ooo
mmm mmmm mmmm mmmm mmm
<oo-^^r^<oujo<\jr)<mr“<oujOHr)
•— •-♦cvjjvtvn.cvjcvcvrrnmcnrir, r- n m < < <
'C'0'C'C'0'C'C'0'C'C'£)'£)'0'0>£ivC'£)'C'£'£'C
mmmmmmmmmmmmmmmmmmmmm
co o> o cvjr)<m ® O' o oj
OOO^h '-h —< ^ ^ cvj
®®®® ®®®® ®®®® CD
m < in ® O' © cvj m < in r- ®
oj Oj cvj cvj cvj cvj n n n n n m m
®®® ®®®® ®®®® ®®
o- o <vj r> < m h-®o'©D<-m®
< 4-<<mmminm
®® ®®®® ®®®®®®®®
r- ® O' 0 —< cvj o <m®r^-®0'©^<vj
inmin>£)'£>'0'£)'£>'£>vOsC'0'£>r-r^r-
®®®®®®®®®®®®®®®®
m —1 cvj
00 r- ©
< < © ©
00 00
< o cd u.
GO CVJ CVJ <
< 'D \o m O' m <
mm in o c u. in
vcr'-^r-osoouj
uumucviOMo
®0'00©CVJ>t®
•j -} 4 -immirir
'G'C'C'G'C'C'C'O
mmmmmmmm
<m®r-®0'©-<
r^h-r^r^r-f^®®
®®®®®®®®
Number 28
Dr. Dobb’s Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, Ca 94025
Page 11
345
D
<3
o < < *■* < ox^xc\jxroxr'-xo>rxinx®>x
<<►-<►- XQ.(Vii/)oooo—«oojor)or^«ao>»oir»0'CX
>- l_J ** O »X~*<nQ«*<M«ffCM«ff(M«ff(Vitf*CM>-*'rMV*rM«*(MUJ
UtXtXIOI-tl/lD*U*UtUtUtUUtU*UlUZ
o x a: ►— z
a *o-auj
» uoataz
o z o i o <
cr — o a o
>• *- i\J U uj >- u > X
Nf-lflWUOhUhU
*h-l-»<.~.|-<»-UJ
a x o >- x
a * w a tu
* uj o * a. z
< < <<<<<< < < < < < < <
o « < <<x<<<<<aoaoaoQ.oaooaoaoo.oQ.
zcQ'OttDQt-ohoii i jiiijiiijii 1 jri i )ZiujiiijHiJi
MJCDJCJJI/lJI/lJOOlUiriUffiUCDOflC-OCIlUBUtr")
z> x < o a o a
O C O UJ Z UJ z
uj _i _i cr o cd ->
<h-o<<<<<ao
oi^ujaKaoK jz
jt-ajoaitD jwum
Z) x < a o a.
o o o i uj x
iu j _j u cr
* * * o * * *
O n CD (/' < O CL
UJ CD CD CD CD UJ o
<m<«^<o<u<<oo«nwnnnN®«j -4 o in u. -o cm cm
in<o<oinoin©inin©o©o©o©oooin©cDocD©uin
cc ru cc cm u. « aDcccccrcocvicccvjccfVJccfvjcof'jr- cc cm cc cm co cm r-
coa-o^.f\jn>riD'Or-coc7'o—<cvjn>jirisor-acO' o t\j n ^ ir >o ®a>o-<(\jn4ir'Or-co
(\j(\innnr)nn(*ir)nn4^^^44^44^ipi/iiririripir mi
ooooooooooooooooooooooocooooo cooooocoooo
co oo cd o u. n
a cl a a a c o
r*> r>-
in in in in in in in
o m i\j n ^ in-a
o o o © o o o
rvj in n in cm «t
UJ CD UJ CD UJ UJ
(\j<3C'jO<JUJ < J < 3<3 <1
omonjincininmin
>ccocDOu.(vj'tr^<o o
ccooucoccc u.
r^r^r-r'-r-r^r^r-r^r'- r~
inininininininininin in
®o>o-H(\jn4in'ON®a
r-h-ccoDcocccooococccoco
oooooooooooo
CO CO CD O U. —<
U. UJ U_ UJ lu U.
in in in in in in
•j in ® n ® cr
(T ^ (T Q* O' (T
O O O O O O
X X
3 * o e
o o -■ «-
_J _l X X
o o o o
CO O CC o
O CO O CO
CO 'C CO ^
o x a x a. a
Q. * X * X X
UJOhHKH
♦ O
in —* k u u
in r*- < o cr o
* (/> % QT * 9 x * <
_ ~ « * K K * K * xxcd O' <x o < ru < -4 < o <x> <
«n xo -j in -o I s - •-* c\j m o <c f— < k < k < k < k < < t-
i/i'0(\O'j(\jir(\j'i)i\isrM'H(\i(\ii\jn(\j(\j^u<wuwuw(j>¥Mj>wu
#l/)*UQtUtU*UtU*U#U«008XQ:»X*X»XUtXU*X
3X1- _| .
C UJ <3
X o
- a a. x
j z o UJ
o < u. cr
O
■ * * * <
X<<<<XI/1
O O t- O ►- O t-
U. U CD CD
CD CD CD CD
< o < ^ <
in o in o in in
o o <\j m r- < o
Uj u u u u Ul u.
® >0 ® ^3 ® ®
in ui in in in in in
aoc>0'-*cvjr>^in'0h"co
inifi'O'C'O^®®®®®
(rcrcro'O'iytro'tT't^^
D<auo<x<i<a.j
OCX ZQCK0DU10<D
uj_jucD_jujin_j_/a_j»-Q.
o n- u. in >o
CD «t CC CD
< r~ cvj \C r- < < <
inooo in in in in
® - <C ® h-UJ'O'C'O'OIVJ
CD CC CM CC CD O CD m CD c n
uj uj ^ cn in r- < a o - ^ i/i
UUOOCCOCC*-**— *-•»—
ininininininininininininin
o-.(\jn^in®^®cro-<tvj
NNNNNNSNNN®®®
ooooooooooooo
i < <. _j < a
in a t- zj b- x
aKinai/’T
<<<«!< < <
D<JdO<aOtlOQ.O(1.01IOI10[10<I<<<<<<<<<U<<U<<
oc x uj o x uj x uj x uj x uj x uj x uj x uj tt ot—aQaoaoa zoo: zoo;
X <J X X
O h- —. CM
CM U CM CM
ox o o
CO O < O UJ
^NocroH
00 OC CO <D o o
o o o o o o
< >o D < 4Dino>onr vO--'^fM^-*m.-<ocrr~ccO'r'-©ncMu_ <i <r cc < co «—<
ino^inccMomomono^-o—o^HO<xin<J<u« 3 ii.<ujin<ujin<UJ
vC—<r^-—<r~—.r^-osOf'-o>£!o>£)o>oou>ooo'Co
CECOCMCCCCCVCCCMCOCMGOCMeOCMCCCMCCCM CMCCCCCMCCCMOO(VCCC\.r'(OCMn»COCM
•J4N0'CDlUO(\J4'0<D<UUJO(M4v0ffi<UUj^ninN0 , (IIQU.(M'l'0(y‘CD
cm cv cm cv cv re r, rrn n r c. cr 4 4 4 4 4 4 4 iniririfir. irinir®>t®®®
irminmmminmminmminmininminmmininininmmmmininininininin
r)^m«or^®0'c^fMm^in'Or*'COC7'o^cMfn^in«or“CO<T-o^cMr)>tu^>or>-
(HMMMMrCrooOOOOOOOOiiHHFiHHHHHHCMMCMCMIMNlMIM
O' O O O O O O OOOOOOOOOOOOOOOOOOOOOOOOOOOO
Page 12
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
c. b-
Z uJ
< O
< cr
_j o
U Q
o cr a cr
o z c z o a
< •—I O —< Q O
H- < t— < <
_J u u u u o
< o c o o o
CD
o a: h- cn oc i
o k- UIK-
_jx»-x<oxx_io>— ox> -__-
aouoQoa^ir_i 30 • z> • z> u o o a. * r: * o
ujojjjwcDu»ojoo#oojjifliniri/)jo
x z »-
CJ •-« H- X ►- KCDO
-»-X<lXa.Xa.OX
m m x
O < < O (_)
o :r a m ►-
^ 1 / 11/1 # 3
n i
® < o o
n i n k
CO W 3
* _i » o
<XXXXXXXX<I<XXIO
*-►—oujujujujiij*—otoaioo*—
i/)i/)jOQQOOi/ua _j a _j rr
z a < a < x w
<(/)K(/U-OH
Tt/ni/i ja
c
Daaat-ujKiraaxQx <tt<a cti-uj»-uji-ujx<x<
oi/iji/iviZKjji/ioi/ioci/iQvii/iuizwzirzoKzcr
lUlUIKCDinuUTJIJJlJIIKCIlKCCt-CCJ^'-CC
D 40
O K-
uj cr
X <
uj a:
o CD
3CDoaa<cr<Da<Q:<o
o<ztocoo'io£rztoo'iocrz
UK<(TCDO _ )H<[EO-)l-<
® o- b-
UJ UJ UJ
< < <
ip in in
r*- cc
Ul UJ
< <
in ip
h-UUIO'O'O'O'OU'C'D'O'CUJO'
muuooooouccmccr'uri
ip®iiiuiuoH(\jr)«oa<ouj-
NNNNMC®a.«;tt(Ctt<tacr
CD CD CD CD CD CD CD CD CC CD CD CD CD CD CD
IPIPIPIPIPIPIPIPIPIPIPIPIPIPIP
•tir«cr > -cD(>Or^(\jn4Ui'0^co
r^-f^r'-r'-r-r^®®®®®®®®®
< u < ui ui
c uj o uj UJ
® < ® < <
IT IP IP IP IP
cm ip co cd ui —•
a cr cr a a -a
CD CD CD CD CD CD
IP IP IP IP IP IP
CD CD (VJ CO O O O CD O ® O O < CD O O O
O UJ O' UI UUUJOUOU UI O O UI UJ UJ u
0<®<CT<I<<30<0<I 0®C^CC<<\J<<<CT<0
ipipipiproipipipiripujipoipcuipip^ipcipcipo
('j(\jip®mujon® 0 '(juf'jipr^<<_)u(\jipr^<e)u«-<'t®r^
<<<<<<cra:a a cLauotjoooccccccuuuu
®®®®®®®®®®®®®®®®®®cocccc®®®®®®®
LniPiPiPiPipiPiPipipiPiPLPiPLPiPiPiPipipipipiripiniPiPip
®U'o>H(\jn4iP>OT-®0'o^Mn4ip»oN®a'OM(vjn4ir
(M?> 0000000000 -H^HHHHM«w(Um(ViMMV
^*-<rvjr\jrvj(\jf\jr\jr\jrvjrvj(\jc\jt\jc\j(\j(\irvjc\j(\jf\jc\j(\jf\jf\jfvj(\j(\j
t- ®
(VI OJ
(VJ OJ
a o
n o cr r- o ct c c h t-
t_j u i-*Hn uj menu o
CTO 'C4DO<QN^ D<DN-J
OM ~«®®®cd«-®®®cc^®
<od ooujo(vi>t®0'<oujor)<
UU UUUUUUUU UUUOOO
cc® ®®®®®®a®®®®oo'0'
ip ip ipipipipipipipipipipipipipip
o •-« m<fiPvOr--®cTo^rvjm >JiPsO
m m nnnnnnn-j-t -J •('J
rvj rvj (\j(\j(vir\j(vj(vj(\j(\i(vi(vj(\j(\j(\j(vj
e'¬
er
o
cr
<
I
u
O 10
X -•
U I
MJh
Z
O O b-
*- z
o -*
x v) cr
u uj a
uj >-
• in
io a o o uj
*-• ® z z >-
a
o
u
ip
UJ
KO C
D — v—
a»- _j ip
z IP < u
*-• > b-
D-
(J
O
UJ
o
<
a.
ip
P-
U
O
X
UI
a:
u
>
o
cr
<
o
<
m
_j o
I- < «-H
— k- O
UlOh U
U ■ O P- _J
(TOO *-h <
x *-* u. o ►—
< -J U«D JO
►— *— _J < UJ u *—■ <
u k- < h- a jk j h c
u cr h- (JO a < uu
_i < o o x n < i- o k k
Q.O a o ui -«
►— O O h- C O _J
u uj m j u uj •- a. u
•">0 JHH>D JI >
x<z<3x<tr<o<
iPiP(\j>cE(Pipm>oiP
P-
o
cr
UJ
tsj
a
to ■—
to ip to cr
v _j >- to
ip
ip
u
cr
o
0
in
to
UJ
a:
o
a
u
or
cr
o
cr
UJ UJ
o o
o <
u < o
000 ^
OXXXr-
o uj (_> tj cr
< uj uj uj a
1
o
< o
o z
X UJ
(J o
o >-o o *-oo o
n *-« t_> •— m •—< <_j •—. •—« x *-•
h-xi-xt-x <aioo<oiooo 00
Xmxr-Xt-jr-t_J_Jr-_jr- 0 _Jr-i- ►- H-
ooaoscotpuz «iuipuz<uu - ou
joipomo <oh>o <o*-«>oo»oo
X
a.
ip
X
z a * a a
*-« to ® uj u. uj n
• b- ►— 1 j— T- i- rvj r- o
- t_> - o - o - umow
*o*o»o*o»o*
X
o
P- H-
- o
* o
*
cr
u
o
< < < < <
< < < < <
< < < <
< I- UJ b- UJ
o to z to z
JK UK CD
o cr o a <
o to o _j cr
uj "> ui o ®
0 to d a a k
o »- o ip to IP
uj a u “) cc ►—
UJ K UI K UI tt <
ZlPZlPZWK
CD ►— CD »— CD CD IP
a a < cr < a
ip ip ir to r— ip
”) CD O CC I/)
cr < < < cr < in
(Piri-oiPOi-
m o to j -) j a
o ®
Z K-
*- a
<jto o to _ j_ 1 _j cn
Zb- Zb- (PlOtPI-
*-*cr •— cr < < < cr
do. oaoa. oihcupoip
OIUJIUJIUIIII JZK
UJUCEUCDU(EUCEUm< a
< cr _j < _j
QlPDKD
_j ") a tp a
a
a
CJ
o
a
tp
*
CD
o
o
cr
ui
u o IP
o o <
o
o
IP IP <
GD UI UJ
< < ip < ro
ip IP o ip o
o
UJ
-*
UJ
< O'
IP o
(_> CD U O
< UJ UJ UI
*- H lP<U<< <IP
U'Jiprvjiptvjiprvj
sC U sD ®
UJ < UJ UJ
o < t_) < n <
fO IP UJ (V) IP (Vj IP
o ® ® ^ ®
< UI UJ o UJ
u < < o —• <
uj - ip ip o uj ip
moo
UJ UJ UJ
< < <
IP IP IP
uooooor-r^ufor-
ivucujMujnocvoo
u —■
m ui
UJ
<
ip
® o ® o ®
cd r- (vj <vi
o u o
ct (vj
OOO'DO'DO' 0 Or^OO<Of^OO<f'-' 0 O' 00 '
trccr^(VJT-(Vjr^(Vj®cccD®mcc(icr®CDCC®cccEm
O O' o O'
m m
O O' ® ® ® O'
m < < < d
— cn^tO' ® q (vj (Vj
®(vj®(\j®(v®(v®rvj®m ® cr m cd ro
r~
u u
T- T-
IP IP
< o u
u u u
IP IP IP
O' O'
OOOOO OO
® ® ® ® ® ® ®
IP IP IP IP IP IP IP
<<OU(Vl-tK
COCO ' »—• •—<
® ® ® ® ® ® CD
IP IP IP IP IP IP IP
O-UUJOn^ffi CDQ
^-,^_(\ j (V.(V(Vj(Vj(V.
®®®®®®®®®
IPIPIPIPIPIPIPIPIP
onip®aioor)
nnrrrn^4
®®®®®®®®
ipipipiptptpipip
K-
® ®
IP IP
® CD
CD CD
IP IP
O U
® ®
IP IP
O —I
IP IP
® ®
IP IP
(vi n
ip ip
® ®
ip ip
-(^<0®<t)UIOM-}<0®<
IPtPlPiPtPiPtP®®®®®®
®®®®®®®®®®®®®
IPLPIPlPlPlPlPlPtPlPlPlPtn
m o 0 ^
® ® r-
® ® ® ®
ip ip ip ip
-t
®
ip
h tvj n 4 1/1 ® o- o ^
00000 o o o —1 «-<
ro>t 1 0K®(To^(vn<rin > cT®0'o-(vjn^ip>0K®0'
—• —* ^^rt^(v(vj(vj(vj(vj(vi(vi(vj(vj(vjnnnnrnnnr)n
^ (VI
irivCK® 0 'o-H(vjr)^ip«CT cr o —• cm m
IPlPlPlPLP'DsOsO'D'CsO'D'D T N S N
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 13
347
in
z
o
c o *
UJ l
cc q
o cc ►
CD 3 l
© O l
ou in £
t— o
O CD
a ©
o o
o < z
a ►- *-
cc a: uj
o o fr¬
ee ►-
a
c z c
UJ O U
*- X
< sc
J wu
3 > <
X «* I-
uj in in
*— 5£ UJ
>- < a
uunr
3 CC
or t a ;
lUjU. X JU
Z UJ 3 _l
C • UJ I <
3 — 3 ax
3 O Z <
a O >- *— 3 O
< O 3 Z
J 3 UJ U <
. U. UJ o
3 0V>
L *— O O QL CL
3 3 z a a
- < — a < <
t x in o o o
O
< o
3 <
U 3
U
o
O U
3 O
UJ X
X UJ
X
cc o
o uj a u
< > u. a
3 o > i
3 o x
UJ
>“ O SC 3
•-• < o >
X Q. < <
3 in it in
in
z
o
a
z
o
o
CL
3
in
►-
a.
3
a
a
3
QQvOUCD'00<rr^oocr)r->j-r , ir^O'^<<xoncDrn<3<rr'
3UJinu.3r^aDO‘oircomr*“<tcC'-<u.cof'jcD©aocijcr)^cD
*o<oinin' 0 > 0 'Oir>oinr*»r“'t(\j>tn^^^*©r)>oin-<<
LnininininininininmininintninininLninininininininin
o
X < <
3f-ojnr)cuojr-in'-'inxxx)cfu-*nfvj^
axo-iMn-jui'ONNftjNownm^No
O^rooooooooofVfvnnmmmrio
«gdoooooooooooooooooo
Q
u < cc
3 >- QU
CC CC < 3
U O O O
z ►-
r in
o x
inH«<('jHuno3unc'0'J(E'0(rNMjn'0<(ti-<
cr^coor- < ^ucr'DiO'Coirff'Oivuj'-'-io.^cc ^ 3
<o^0'Do<0'0in'0inNN'J4(u-J>»nn^n>D< ^- <
ininininininininininininininininininininLnininininin
in
z < CD o o
M^J\J(VJ(\JfUn4N4X><4'00<0(\J^33n u_I
U0©^<'JO^in'0'0r~^'0o-*r)-t>0f^3Q:>-Q0X3
uujoooooooooojojnnmrinn< 3 a < o o
<0)000000000000000000000033
•f © a
3 o o © © © <
< < o © © ►—
«n tn tn m «n in «
CDCCCDCC'CrCDCDCDnjQOCDCDCDCDCDCDCCCDCDCDCDCOCCCDCDCDCCCCCDQC 1
oxx xxxxxxxxxxxxxxxxxooxxxxxxxx
uccaxctattCCttttffccaccaccciaCECCuuccttffttctaacc
' v,r ' >- occ cccc
o o 1 < 3 •-» a o t-
<_>3cci_;coo*x>-f—h-au
<U>->II>-l-»-XXX.<0
SC O O O O 3
3 0 3 0 3 3 0
< Z U < 3 > O
i/iinoa juk < z 3 < 3 > o <3 >->-ii>-i-»-xxx<o
x in o x 3 a in ho®aihua>->-Hj-t-uuuuuoacuo
unct-zuii inx<<xinooo3>-»-33000_jinoc.o_j
O CC CD CD CC CD 3
CC O O O C O O
O U U 3 U 3 3
- (vk u cu'Oi/h\j< (\J3m330-*r- 'C in
r*'>to<iinc>30ca''-'>i'0(vj©LncDcrof s 'CDC7'crnjcr3
<©>t^'n't’0'nir>'0'0r^r*“>t>t^ro(vj(\j^©r)<«n<<
in3inininininininininininininininLninininininininLn
o
O a < CD < CD 3
ino©r»njr-^c\jrsr^riKxnjs}-vnno©vO<(\j a o
xooo(\j(\j^in'0'0h-oino^f\j^x)r^r s -a >- 001
d)<oooooooooi\j(unnnnnr)n3Q: <00
4CDU000000000U000000UU00033
aooMfni\j 30 <N'CU.u.'-UicuiMiJO'Hoa ru ^
oinaD<xoo'<r-oa'0<in<(\jux5>xr^ocDcr3'JCD3
ininininininininininininminininininLninLnininininin
cd 3 < r^^r-r^r~f\jr~-f'jf^xof^^x)'C'C'»'^'^oin o
<33 ofij(\jn^C'ONN>jo-'ajnin-cs-<v<Q 1
h- ex in ooooooooofunnnnnnnciax o
<<00000300000030000<JUU0033
3
© © © © ©
« O O O If
NO'<0)D3-nXJNO'<00330«(\)l , 14l/10MMDOQliJO
crcrticra:a:oocccocooc33333Ui3 3 333333
<4<<I<I<<<<1<<<<<<<I<1<<<<1<<1<1<1<<<<<
inininininminininininininininininininininininininininininin
n n 4 ip «o co <
-4 <t -4 >»
© © © © © © ©
<<<<<<<
© — c\jn>tin>nr^ooO'©^(\jr)<jm'Or^coc7'©-<(\jo^iri'Or^ao<7'
wivj^ji\j(M(\j(\j(\j(\jt\jnnnnnnnnnn4-}-t'J-J'J-J-j-Ji
mmonnnnmnmmnnnmmrinnmmnrinnmnnmn
—*rvjm-jin>or-cDC7'o
inininininmininin'O
r'lmonmnnmnm
tvj
X)
rj
O
CD
X<('J3-^<oaiTUJ-J3CEffCCnc<a<-J'£:<30K^
>O'J<3CD0'O3OfllCDOl/'M-3OO®CDaOM0'O
in<o<in>»>t'nininin>#inr^r-fvj4-r)m>t>t — <<x)inco
irinirininininininiririninirinirir. inininininirininin
a ►—
o 3 in <
oinonNNnn- 1 ow-ox«o(vi'jn-jno3 oj a o
<a3o^(\jn^«o^NM*)X'<(\jnin>oN^3 001
cd o cc 000 © oooooNMnnnnnnou; >- < 30
<<CD00000000000U0U00000U003
©
rvj
o
a
m
< 11 < 11 < 11 < 11 < 11 < 11 < 11 < 11 < 11 4 11 < n < n < o < 11 <
tntntnmmmtntntntntntnmointn
• X) • 3 • 1 * •— *0 *u »o * o • o • 3 *3 *0 • a. * x •
0<0000000303030a oa oaoinoinoino30'T
h- a v
3 0 ►—
< O II o •
X < z o <
a -•
3 a <
3 3 ►-
o
o
a
o
in
a
o
o
in
3
cc o <a u
-* h- rvj ►-
** 3 *» 3
» O » O
O
3
a
a
o
o
3
o
o
o
3 o z
000
a < o
o
© ©
x cc cc
000
3 ai ou
< a
a x
o 3
3CDoaoa:occoaDoa)0£EoaoccoccoaDO(Doa)occoacD
0000000000000000000000000000000
3333333333333333333333333333333
OtEUDCOirOCCCDCD
0000000000
3333333333
D a x CL
oincx
3 cc _i “>
3 < a < a
o o in o x
3 _i “> _j ->
~1 CD CD CD CD CD CC CC CC
oxxxxxxxx
3 aaaaaaaa
in o
o 3
3 a
cc cd u o 1
o o
o o
1 _j < 3
•O CD
C C
O O
in in
n- co
>* 4
CVJ OJ
CD O O 3
© c c c
0000
in in in in
© oj m
in in in m
r\j oj oj oj
c — ononomoinoinooooofvjot'JOOomomoinQ'j
0-JOJO.JC.JO^OJO^OlfOlfOlfOlfOlfOlfO-JCC
33'H®<(\J4CC<(\J4inMJ'CC3^UJOCDOtT'CDinr‘©OjOf\Jl/lS
c c • (\j n. >4 >1 lt in a a. c a « a oC33©cfv-(v-3 >1 ir ir x. x
000000000000000000000<!<l<<i<<l<t<i<i<i
ininininininininminininininininininininininininininininininin
in>or^cca'o^njro^in>£!r^cca'0'-<ojn^inx)r^cccro^ojmjjin
TvOvoo«C'£»'£)'C'0>c>'Or^r-f^r-r^r>'n-n-h'h>iocooocccDco
ivyii hi ^ I- w u- v ^ uj n ui i' u, it u « 11 j ui r- uj u 1 o <-< iu ri j it r-cccro^ojn^inx; cc O o ^
in m ininmininx)X)>0'CvDvox)vCvCX)r^r'r'r^r^r^r^r^r^r'CccocDcccDcc aocccDooooooo 0000
oj oj ojcijojojojojojojojojojojojojojojojojojojojojojojojojojojojojoj ojrvjojojojojojojojoj tv oj n n
ao(Vjnn-jsco(j‘<cD
'Cr^r^accaao'aa
<<<<<<<<<<
inminininininininir
r^cooo—•ojoi^mx;
COODCOOOOOOOO
ojrvjojojojojojojojoj
© o-
sC o ©
c ir 3
o o 3 oj
o o o <
< < < <
in in in in
in in r- < u ^u. shiud^iT'O
<<<<< <<ccaaocccrcc
<<<<< <<<<<<<<<
in in in in m ininininininininin
co in o- o rvi n 4 in <0 om o>
OOOOO © r-4 ~ ^ r*
nnnnrs n n m nnnnnnn
Page 14
348
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
o(vj^<£>^ninoo
vT>j>TvTLniriin>y
oooooooo
o n ^ co o h ftj
IP IP CP
S ^ N N N f* S
iP'P'P<tcEa'iPo^(\jn>tt\jr^o^(7''-*nip>onipr^CT'—nipr^O'-Hmipr^O'^nco — >t>co'-<n<tiph- 0'o.-rr\jr)ip>Dcr~-«r-iP0'r'J0'
iMfi(Vj<vjinmai'0'0'C<C'0^oo-<0'oooo'{M(>j(\ji\jnnnnn^^^^^irinir'C>o^)^NNNNN^occDcDXCDi , i^in4ooino
h-p-O'O'r^r^'Cf-^h-r^P'-ooooO'OooO'nfPnmnmmmmnmfonmronmmmnmmc’jmmn nnnnnnnwi\i(vjH« 4
0'r^r^(\jojfvjf^<vjf^'PiPcof^a''X)a'n«£io>cfVjr)-pooof\jipa)-<r)-.>tip^r)f\jnoipo—or^cDC7>'Poa'—>cfvja>vor^f^v£) Hi/icc^ij'on^socvjny
O' n -t ^ co ^-•oocT'—•'-^^r^r^h'iP'Ococpfvj'-'—«'^f\jfvj(\j(\jr r )nc7'Or'r-ia'Or^f\jO(7'r'f\jocO'Of\jrn(\j>x5^-noa' oipo •jN-t^iru/i'Oncor
flco , coa'a«£fl0occor*-0'0-0'co'0'0ecr^r^r^aooooooooorripip^ir)irip»cr r . iriP'PniriP'CiP^DiPir. 'CniT'CiP'O 4irir'£iP'£>4rv.(\.cv^-^-
vi
< CD < CD O
r^- cm r> f- -« rvj n^ir«r'NNrt(\ji\jn4ir'ONx x x x xx)<x«oi\i^«oi\i44)oi\c4«oi\i^«n«Hn«oivin4« o-cvin^ « jho^ouju.
-jiPLPLP'£)vO'P'P'D'0'0'£i'0^r^f^r^-r~h-h-f^O'-<rvjn>jiPv£)h-xoooo^H'-<—<^Hf\jrvjf\j(\jnnr r )n>t'JiPLPLP>0'£i'£i'P'£)r^-r^r^r^r^r'jo^-«r-«Q:ccj
oooooooooooooooooooooiMMCMNiMftjNNMnnnnnnnnnnnnnnnnnrtnnnnnnnnnnnnnrxoQOjjii:
oououuuouooaouuououooouuooouuoooououooouuuuuoououoouuououuouuouauouou
UJl/lCDlTinCDO'XlIIM’lIM-JCDn^.J^CCXJf'XQUU.'T
<<CDCCUOUJ0'NQ-'O(7-rUJ'tOU.| J . ^-JUJU.QliJ(\JlO
f^<r^iprvjojcc<o<(\j(\jcccof^ccor^t\j—im—.c<<rvco
ipipipipipipiptpipipipipipintpipooipipipipipipipipipip
v a c x c »-
►— Q (J 4 O O Z C 4 CD _J <J
t-UJ d DC- X U < — X — IQ < U. ►- X o
*— X U Z UJ < NZ^XhKf-l-«Ji-i/)0*-OZ>-XXJ
cuozziua ou.zoa iiiuu33^o:Duii/i»-DC'ar<
oi^*-h-)-)_j_ji 2 izoocoao.aactQ:Q;Lnip>->
<iQfvj<sOLP<rcru.r^cnujuJ<ujOLLj<TC3a)o>Dcpc-<ufv
a ® r- - ccrijj^^o<iiijcc'u.NCciroDD--iiu.u.
c<-ir4iv<<co(VJir<a «cror^pjc(v<'-cr^-cc>j<
<XlPlPlPlPlPlPlPtPlPlPlPlPlPlPlPUJlPlPlPlPlPlPlPlPlPlP
_j ►- i a t- ^ >-
za UCD JK CD O Z O < •-< < o
a a k a _j _i *- »c ac-*oo»--‘i -- u. ac x oc
H JliiU < «J X ^ Z h<KUH<I“I/1C)hoZV1X>
xuju-zoi ozocr :> o cj a. _> o a □ u i c-du^ok
ujiH^H-j-jjjiiixooooo.o.aaaaatPtPK*-
ltl*.®CD(VNaCO(\J<OMEff'-i^'OMMtUMJmon
cDor r )r-uj^'«Mi*.oipip<o>oujo<o>-^oiij£r('-oiijouj
< o <r irr- ^n<oooi/iooo<-nsnsHHi\jHoo<
iPlPlPlPlPlPlPlPUIlPtPlPlPlPlPUJlPlPlPlPlPlPlPlPlPlPlP
a) o t- —<
< Q Q X h D to 4 a I O CD 4 t-I
I'OaZOQ.DIIIlDKQOUIXUlMhJ —« CJ —« o: CJ
cj_jxou,zxo*:zz*--..-.»_Kj-aQ: u ~ o « >- a. < >-
Q.UJfPZ0UJZ)0>-'00>Xl_)<_>Z)tJ0:D4XJ— l-Okif-f-
uiHHHTTjiiiizoooaaaaaairifliflifli-
-NCDU.Oli.inONO'^UJD'CNOC<<JL.iiJO(CCff'0>CU.U.
f^Q>C'COt\Jf r )(EliJ'}(\J0'CEU. l U,'U<U.OU.'£)UJ^0UJ0U-J
m <\j < ip o 4- -jcO'£>ooip<<<or)(Vin^)r)>j(\jo<c<r-r^
iniPiPiP<iPiPiPiPiPiPiPiPiPiPujiPiPiPiPiPiPiPiniPiPiPip
O' >o >o
4 ~ O'
~ <D CO
rvj oj >o ■£)
ip 4 o co
« <0 co
m o r^- 4
n c\j m 4 cvi
CO —• f\j —■ CD
< a o ic w
o <j<k o u *- a x <
— »- «p a caocD-jc-aaoj 4 — _j
c _j x o zxo—'ZZ*-»»-c-»-aa_j
4 ^ Z
O l_> (_) •— 4
»- o z a
c _j x o zxo*->zz*-'»»-t-»-aQ._j »-©~*zol<»->-
Z4C-ZOluDDXOO>UUUDUCD<lDhhD^t-^U
iiiiiHH-njjxxxzcco(iaa.[ni:aQ:Q:wiflhx
®nuu»c(MMcccoH®u®<'Jin4 -a u.<4(rr.(Mc<c
MCQ4O«n<Ol/l®UC0 4 4UCDOOU.<O(VJOMElIl-
n<4HC04n«(7OO4<C0C0O<O(DIM44N«H44N
ip in ip u; ip iripipiripipiriririru,ir<tipiririririririririr
_i o to <
o H- CD h-n CD to )C cl i o O CD o
_J I to O a O 4 K^XCDC/ltMl/ll/l-IC/tOOCCQ.
o u.oc-zxoanzh-x>->-K-X4»-(00o-<zt-ioac-
Z c-ZZUJDOI/lZOl/lWUUDUH'rowhl-DlUI/lIU
uJir*-«*-"}->_i_ixxxzocoa.aaaa:a:a:a:iotn»-x
o rvj r- n oj
fO PO O' co
^ ^ vC
^■orupaon(vjN^(\jn'4®4^(VjococM*)o^(\M\jN(vjeoM4uin>o
o^-of\jroro(\jt\jcoooooor^—* — r-«^^co(\j(\j>or-(\JO'C\jc r )rom^r r )
^ ~ ^cc^r>r^r>r^r^>or>r^h>r^h-cor^r^>o«pr^cor^r^r^r»0'r^
—* o o> cc
n n co
n n rvj n
o o o
O _J to
< U. X o
CD CD CD O
< < < <
f\jipo(\j®s(\jn>oN^(vjn.40M*)o^«oNo(\jnniP(\i^nco4M
<c niP(\jn>trHPHCo 4coc\j'0'0o nr-ipcocorvjiPtPiPO'O' 4 voipcunn
r*f r )P r )>00'COCD'D'£JCDCC'00'CDCCCC'0'0'C'CCCDflC'00'0'0'CD
x wna z < 4 <j cd 4 <
uj (/) < o « k o o^(\jnNN(vjns-(\j(\inNNN(\j(\inN-H(vicvin
aa-jooxuj ooooooHHH(\jMi\jt\i(\jMi\jnnnn.f4 44
Q O l/l 4 unc ct oooooooooooooooooooooooo
4 4 4CDCDCEIUUUUUUUUUU(JUUUUUUUUUUUU(JU
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 15
349
SYMBOL DEFINED REFERENCED SYMBOL DEFINED REFERENCED
CD yO (V
>© r- dj
me in
r- »c ®
yo in cc
mo -p
dj
m d- yO
m \C m co
in m d- >r
o .p
o -p
(Vi rvi
■c
cc
m
■P m O' co
O' -p t*-
m d- -p
CD
O
DJ
O' —
in >p
m r*-
r*- >p
o
dj rvj
in co
in o
O' .*•
O' o
»n d-
f- n
yO o- r*- m ■£)
yO m in m ir
>* d> m r- Yp
>y o
m (V
O' (VJ
m
m
(V
YC
m
OJ
CO
© m in -p
yd n in (vi m
*$■ r- m r- -p
inoN
o o m
(VI DJ hH
o* Yp
r- yO
>d
(VI
m
00 D- >p
d- in
•p o (*>
(VJ DJ
•p in
DJ o
in m dj p" o in
-t (vj in in O'
r- m r» -p
* «D CD
© hh ©
DJ DJ —
•p co
dj O' o m
h-. o -n
yC
in
m
o o m yo
<n co a -J
m dj cd m
in -j
m -j (\i ®
(VI O' ^
o> m
dj
P*-
co O' co m -j
<p © -j- -n o'
m d- .p in h-.
jno m dj p-
r** ® m o ^ o'
h h(VJ DJ DJ
dj m -«O'
DJ O' CD yO
—• d* in
Y0inm.-*©in'£>c0DJ0'C0m^0'in'^D-~-o>*>*0'D-Y»r^Y0('j.-«_«Y0m-HD-0'DjinmDjDj<n**r*-0j©0'r^-*'0
m^mcDO'0''ninYninD-D~D-Yno^oo'omcDO'om(vr^O'OYODjYno'ininr^D~^<tOYOino^Dj^«^>tm
dj co Djm«tr-D»commc^(viin ^(viHHHHHHHHMmDjH m ivj ^ m yc 4
o «p cd o m CD
•p .p yo *> o m
m m *-« dj co -p *•>
o^mm®inYCj®0'-'inmmo->jDjNjo
^Djh-r“0'ommDj^Di«D-^mocoDi'£iO'( r ‘.
m o o o —• .p .p m Yp Yp o o ^-<<-*DjcomDjDjm
u
n
ii
ii
ii
o in co
in in -«
(Vi o
ccvCO'OvtvcoO'-<coo>c)'C r^cvi
CDOr^D~D-D-DjOinr^OODJ CD o
m m m m p^ p>-
m m
o o
f" yJ
ii
o _j a i-
m d o cd o in < cd
<s cc (E -tin yd t) i-i-i- * rr rr a
QT'-^-'Djmzzzzzzz x
irKY-zzzoooooooaain >>>uj
JJIIIIIIIIIIIIII i i i z
m4 ^ffl-NDjO"C«-4D)4<»4mino
O (VI m-tO'44'O'M-J'J't 4 m O' DJ DJ DJ
(V m r- .-.^Hnmmo
mo-inoo'j'£®®j-<(r®om(vj 4 oin®»iM — -p in in
mmO'DJ^^DjDjDJN®OOm4^DjDJNNDJO»M CD CD O yO
(v •— Dj in in ^oo^->^H^Y»^^^oo'*-*^m j (\. d. j
o a o o x * in in
(no oo^*-azzaa i x i
za. >o<moiiiHHin)xo dj j u
xx
Ul Ul X OOOOOOOOOOQ.33DZ)
zz zooooooooccooooo
o o < oho o <I <m
ox in - dj h in i- h h h j j j x x o in
KHio.a<<<o.ai-i-i-jjin(nin o o o
3DUUUOHMOOO:aDDDDD<<IlilUJlLl
ooaa.a.a.a.aa.a.aacLaa.a.a.acrcrcra:a:
D- m a
yd r*~ cu
P" P*- O
(v a ~ cc m
r> r*- O' m
in <4 o r» o
YO Yp o
C O CD
D- vO O
m DJ DJ DJ «*
O' in «n yc m
-p -jo 1 in O'
—« m r~ dj
in r*“ in dj
O' y* yO O'
m m yO yo o
cc m o' in >p
.p dj d- in o>
o Yfr
•p >p
e co
(\J CO -P in O'
m r in in —<
•per- 'CO'
r- CD D- o o
Y C Dj CD IT rn
yJ dj d- in o
y© m
m in
yC r-
(VI
yO
cc dj
DJ
O CD
r- yo in in
~ O' <t — —
>t o fY- c o
fh m ^ dj m d- o
>n in dj cd yJ >r
Yt co in dj <o in co
dj dj in
m m nJ
yO fw
o o ^ ®
r*- m o o-
in yo y» m
in o
Dj Dj
O CD
o <f ® r- r*~
o p*- m o ©
(VI cc D- 'co
iC mo inir m r-
Yjina ho >t >j
yJ CD y® (Vj yC in CD
O r>- r«-
(V (v m
yT ^ r-
NOIMf O' yC
© r- o m o o
in y* m in yo m in
yO
d» moo o -*
m dj co on © ©
yo co dj r- mo
© o o m m co ^
m p- cd dj mm
yT co yJ in m co
c o
(VJ r* DJ
YO >-< p-
in co yo m —« D- y» dj
p^oD-om o o <t
m m m m yo m m o
DJ DJ
DJ o
DJ DJ
DJ m DJ DJ
dj m in y*
o ® i/i s
y£) yO Dj ^ D-
P- CO DJ © yO
(vj k in cc
O DJ inNN -JO p^ dj
^© — - in®- om
~ -t ® -p ^m m co
DJ ^
DJ
© r>-
m yo j m ®
-P'ONODJ
^ in m in in yo
m dj dj
o o m
m m o
o o
^ o
DJ DJ
0-0 ®
- ^ Yp DJ
m in in r-
cd ^ -J CD yO
y£> CD —• O
dj p^ p-y m co
Ytop-^Yt^m'O cd
O®^ HH^OO CD O
-H-®M®Yp-M-P DJ CD
cd © mm in
m dj yo —» ©
'-y y£) co
O ^ Yp (Vj -rn
ffiNONODJ
© in m in in yc
m m o
o o o
m y£) in
o r*Y -h® pm
y® —• m o yT
m dj (VJ dj •—<
mmmmp“YtDjcoop^mocDooYODjoDjp^m-^mD-p^^
moo-YOooco-«r^p^cDP--tcDococcor~Dj(VjocopY~^
ininin4iniP-N«««®wNNNHHNHHHO-M®
YC®«OHHinNoon®OHO' oo nHNomin®min®ono(VjooDj®'M®®mrMnsm'po®
0inDJinN0Dj40O0©o0'p®>Minin^o®®N0inttiC0s®(Vjffl0(M®®0ooDjOiMYC
Hin-p - j oh HfflDjmnDj HH^r.m n n 4 omnmin®Djmm®YpH(vjHDj(vjH
ii
ii
ii
ii
n
ii
ii
in <d Yp o
o © -M ©
(v in in ir
oin®4 j®omM\i
©mm-Mp>-mmp^mDj
irmmmeccccDccccm
Yp in o
CD CD »h pm
r> p' m cr
o
co
D- P*- © — P*- O
N04-PHDI
p-m p- m m m m
hm m
O DJ
^ m
Oh®
®®h
mom
oin®m(viMn«OHNOHNms
HinoO(*)®ODJMVl®NNNHDj
YpcvD-mnD-YCD.© p- H-.
H-.mDjoomcomom(vj
ocoocoopHoomom
©m^mYDYrDjYp^YC^
p^ cd Yp
HlVJOO
m (Vi — (V
o m <d
yP yP O
in a
u. h (vj m <i u ph cm m a
_!>->>->- < oooooo
aaoo:a:>->- <<<<<0
uuouuoucooccoc
<
or cr
u 0 o
UJ UJ u
O O U. U-
< u. or
li-ZOOO_JI-
x 1 x 1 x u. in
o a o o u >h z
liJ U_ liJ UJ UJ UJ Uj
Q O
z a
UJ UJ
_J >- ►— Q. I
ZH 1300 O <IUI- C J < ® u Q K < X
otp- naaujj®®i- xcrcrcrcrin z_ioooo_j»-aQ.a
*- *- -J-J-JXU XXUJ OOUUUK uj<zzzz<ujx xx
x UJ <UIUJOJ-h nit.ZZZZZZZOOUUJUJUJUJlQ:DDD
xuuui-
< O O O X
o o o o o u.
Page 16
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
350
4®<da.ocu.r-®oj<roinoo'©o-o^coin»-'incr , -in'*C'4u.ujc;oiOjOi
oo<ict'®on-—< r-ojmodO'®oju.coomd®cEa:inudC7'incT'44N-ujN-.~
0o^nNo-j^«o^u(vnooso4ujM i jooNNo^' , )iro(\j4onu
oo44nnLn.*,*r\jin4d40jf\jooj44o40jinooojin44ojd4ddnj
f\jB^)ONniijN 4 40ooaj-Htjaoou»ou.ooao4 o d oj o o ^in>o
t -j 4 44 m
o-r-ooiooa'inoujooujO' 4or>-^u-(7*oofvj«i .-<>44 O' 40dui©or*~©
no(VJ4no44'J4(VI04444'tN444Min->n44^-tW-J4(VJtVl4(\J
OQO^n(’)u,|\jOlflO^0'Ok)rtHNo^(VluJ' , lOO>t4^OO^CMnc0in(\l
noO44'0'>l/HVi4O^)4O444OMUUn44(M(\J444N(\l444in44
noa«oosoo(MQinNoaiHouoi/iani\iuon4oui^®ooin4iviH
4ni/14(\J0ir(\Jl/14'C0O^4l\J-J044'Jl^-JO44(\J-J4l/l(VII\J44^4
or^N-oojoo40inN-ON-r^oindmd4ujinO'inoo»-<oj.-<4*-*'-*4oo4
(VjnoM^O(\u/l-I 4 O O d O OJ 4 44l/144in4M/HVJ4l/'4 4 4 4 4 4 OJ 4
rvjooo4^-«4niijf\jQHr^QOf^on^ujO'4or^nn—« o4ooj(\jooqu
4 ® O O 4 n 4 44domooo40j444 4lDooiT>44 MT4irinM(Vj44
4n4o^o4i/i(M , iniiOBiMii(M/inu.oo40oin4 4noni\j^i\joo
44n^4(\J4444lflMOin'04in4ir4(VI(\JNO(\J44lflin(VJ'J4l*lir4(VI
doN-N-om40joujoj—«nor^—«ojoom*-«or^mo4UuJ©omor^-a>CT'o
4l\jno(M4 4U104lP4l/)(VI0 4inM(\l4in(\l0404 4 4(M04(\in440
o(\iooooc(\i4(Mn(\JNoocoi\ji\(«oin-on«oo^oo4oo-ooi/i
M4nooinrvjui'C4 4iri4no4iH4n(\j44o4M\ji\j 40 ® 4onm(\jco
o4nir^i r )nu.No4nino«rtHrtnawna^Mnfvioo'No(vjnoirN
044i’)®in440(\lin4 4IM44 44Ml/144l/l40ni/l4N00®4440
ddor-r^OLTimo4r)ujnjmoom4oojoujojoor'-®inr'-o^«N'0©do
d4(vjoooj44©4d4d4d(vj4 4 (\JirN4in(\jon4 4©o®o©©d©
NO(\iODO4OI\i4(T0'niiJ4®OUM\JO(M\l»-4Oin(VlO«NOn4U.n
0^4noo<(\|^ 444W4®4l\J44®04J144n^monoo®®4®
OO4n®(\IOU,lT4NOO0'O®4O4H(VJOH«i l jn4nn®OeNNO(M
0044n®(\j4 444IVlM4(Vl4iri\j44S(Vi44 444 4lfllVJ0ir004ir
-hn®onn 4 4 4 o 1/1 - ® o (\j 4JioiiinNon4i/iooini\j-nuooo®
od4njooodd(vj44doj4ojd©44©©4d4oo4d4dojo©oj4
N-N-oojocN~on--Oj^«4—Ojnojo.— oc®omor^cc4d(vr^o(\u4®4
noM4non(\ji/i4i/i4 4 4d(Vj4r'-40j©r*-ojdOjr‘'r*- 4 4 1/1 4 n 4 441/1
000000000000000000000000000 000000000
0lilU.O-Pjr)4t/1®N®(/'<®UDUlU.O-<(Mn4l/'®N®0<®U0WU.O
-*-H«(vj(M{\j(\j(\j(\j(\j(M(\j(\j(\i(\j(vj(\j(\j(vjnnnnnnnnnnnnnnnn4
dddddddddddddddddddddddddddddddddddd
monooomnoooooooooomoooooooonoooooooo
o c u. u u a o cr 4 u a (\iu.<ML®ak®4®iLU uui40.r^od0 44 U-
O O ® « -*(T(Ml/'ONO®®S0(>0'-'(\JN0UUJffiUI/>-' d O © CT C ® 1/1 O ® U
0O(TOO(MO(VlNOOOlLOH-40i/li 1 j0>44(tcoU®®l , lI'-«J-®4O
OO«Oi/1(M\J4O(\ll0N4O4ri4O4 4Oll/ll/lOO4l/1Ol/11/1(M4( , )O4O
^®N®riN®-<QOni/13H(\JOO04(>®HljJ|/lJjnouJQO4®OOQO®
1/1 ® o in ton4oo®i/i4oi/ii\j!\jtn 4 404 4 4 4 —* 01 4 o ivj 4 o oj 0 / o oj 01
r^r-o<_)oa«£>4ccf^O'-*kncr)rvjn<rvjooQu.oi\j4tDm(7'CDouoorn4coco
400Ninon44ff 1 WK1404 4(\nni'JI\J044l/1l/IO' , 14 404004 4ino
do^o©4ouor^od00ooou.o-«^iju.4modo4®©®ojoo4o
40 nn(\i 4 ri 4 (M 00440 Ml/l(VJ 404 l , 1444 in 0 fl(\ll/lH(yji/H\jinMt/l 0
(\j4ccoi\iujno®Q®oo®oni/iQ®iMooo-iO(\joon®nu)®n«n4
i/i4(viwi/i44(viino<M\jN4oinin4oinN(\jin444noinon4oininin4
ri 4 H(\injioo 4 ®N 44 o(\io-*i/i«(\jn<ooi/i(M , )i/iooo(roo 4 ouj
M4441/14004inon®(\)OftJl/i4044M(Vl(\J444^4on40(Vl4M4
©40j-«<om4000duj®®od00o©o(r0jo®o®in4©oN-o0©d
(Vl4in4 4MMf4(\J0n4ir004 4 0(MlT(VJ4l/'lVJir004 4nM40404
®©0'4©or*-r*'Oooj©d40oo©®oodoo®o4o©uj®od®©d©
inf\j4i/i(\Jinooi\jn4f r i4 4oo(\j(\J4oinin 41 / 11/14 —« o 01 4 4 o 4 oj oj oj oj
4H>on(\iooQoo(\jnQU®®i/i 4 o o —« —< < 4o®m®inoo(\j®nco
44ini/i44ooo(\jin444i/)oni/i(vjo(\jin'J4infuo4in40(\jinonoin
u-oo(\j<Mni/i(\iO'oi/iouo®iij®®oi/i4onoQ440(?®(vjQ(viQO
444f\Jin4ri4a'4404rv J ojon4inoo4i/icvji/ii/ioinin(M — o4ono4
O4o-«oooor- — da'0j©oojod40®ooooo-«oo©®o©4©®<
i'j4(\j44(vjwino4i/i(Mnon4n44oo(\jino(\j4i T Mni/iinoo(vj4nin4
OU-MX!Oni/l04QMnoO(\jn0U««"0O0<OQO00N®lil( , lUJO
04 4 1/11004401/140401111/1 4 4 4l0on(1l«O4(U4W4O^in44 4 OJ
'C o •—< O' o^©o®noouj®omod©oodO®'HOOd©<* «—• l/i 4 in o o o
® OJ 4 4 43 , in0Jl0i10JO4O44O40l0JO"14OHiM4 40404d4040
N-o4dor^mccuo-*-«CT'C!UJUJ40jooojooocoooodooojmo40N-
ooifii/ioouun(\joj4n404 4oinon4ri4oooin\Mrvjoji/ii/i(\j(uM(vj
QM^oooo4ooojoo(M>»«rnno(\in(>(\Joo)nffi®on(\ioo®o®
O«i04(J'O(\l4noi00J(Ul04 4O4O(1JI044l0OHi0inoO44(\/l0OOO
ccr^ooN-~.oood(vm<o,©ooinctmroodmcco4cr~©o©c:cino
l0O0jOOno4W0'4 4M00JMO4O44O0J44ON4OHi00JO4O(UO
OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
H(iin4io®s®a<ffiuouju.oH(un4in®N®»<®uDUJU.oH(un4in
444444444444444ini/H/ll/11/1l/1inini/lini/1l/lini/1ini/1®®®®®®
ddddddddddddddddddddddddddddddddddddd
ooooooooonoooooooooooooommmmmoomooooo
l/H/'l/11/)(/ll/ll/ll/'l/l»/ll/ll/ll/ll/1l/ll/l®l/ll/ll/)l/U/ll/ll/ll/ll/)l/!l/ll/ll/ll/l(/ll/)l/ll/1l/)l/l
o II
UJ II
U II
Z II
n 4 d o
in 4 d oj
— -lun
4 O' 00 4 O'
co n r\j
o o —• o o
(U (\j 1/1 4 o
in o> in r- cc
Oj d Oj Oj Oj
«Hin4 4HOjino'OM>o-<Hn4an®ino®N«®N
in'£i^Nin®>CrH^^ r -^inojoj40'ina''-nffl®®^N-
oj oj o ^^« r -^ r - r< (\ i -(v-(v^r)®rii/iooo'-(io
®M*iin«n-<Mnn®®'H4( , i®4®o®
®0'®N®ff‘^-4®®4“ - ■“ *
® ® o. (ij Oj (> r r — — 1 —• —
®®H4n®4®o®-®oooin(M5'«in44
®4SNnH(^inn 4i\/ojnooj(vi®nnin®^
^^^^-riojiVpHtvnr, r r- ® ® © o o *-• a ©
o II
X II
X II
>- II
in n
O > b-
< <■ CD < _j u ic t- z i o o
oo-h—<o-h—« 4 ® u o u u a. —• cc ►- ooxx *-*oao <
ooooo-*^^zzzz>->->-i-aaa x v) <t < x x a i- >- >- _j ►- h-
►-f-l-l-f-l-l-l-DIDDDUOOU* ^ ll O. ® h h o 1*1 r ® k K «J U U
aaaaaffaaaairir®®®®®®®®®®®t-i-hi-i-i->xK
2 ;
3
a
a c c
a: (vj d
o o
o CVJ (VJ
Q O (VJ
0 0 4
(VJ (VJ 4
in <vj 4
o d
4 0 4
d o ©
in o (vj
o o
4HO
o tvj o
(Vj n (Vj
(VJ ON
4 o o
4 no
4 4 0
>0 0 0
4 (VJ 4
o (vj m
OJ 4 4
O 4 UJ
0 4 4
O >o o
(VJ 4 OJ
N O (VJ
O (VJ 4
0 0 4
0 0 4
(Vi ~ >0
in OJ 4
O O O
O —« OJ
O O O
in in in
mom
r~ 4 m © u.
® onhu.
oj d d © o
m oj 4 oj m
HN OtVJO
o o oj 4 m
0 0 0 4 0)
m o o 4 4
n n n (3 o
4 (O OJ 4 OJ
o n r>- o (vj
(vj n o (vj 4
(VJ o o o 4
4 0) 0 0 4
4 n (vj ® ®
4 4 in (VJ 4
d © ® r- o
4 (VI 4 o (VJ
O (VJ UJ o o
OJ 4 4 O O
O 4 O (VJ O
o 4 4 in (vj
4 d OWN
OJ 4 (VJ 4 O
o- o (vj in o
O (VJ 4 4 o
C O 4 4 OJ
o o 4 4 in
4 in >n o O'
4 Oj 4 OJ 4
•H N O M d
4 o oj 4 in
4 C O 4 O
4 o O 4 4
o o o o o
n-Jl/ldN
o o o o o
in in in in in
0)0)0)0 0)
o r-
r- o
>-« r-
o o
n- O
o o
O O
O 4
o ®
4 in
in cj
4 4
UJ o
4 OJ
O —*
OJ o
OJ 4
4 O
4 O
4 O
d O
4 4
O O
(VJ OJ
O (VJ
o 4
o 4
O 4
n* d
O 4
O ©
> OJ
N- O
O O
o o
CO O'
o o
in in
o o
U.’ (VMVj ®
o oj in o
(VJ 4 4 O
O 4 4 OJ
O 4 4 in
o d o O'
O 4 OJ 4
N O OJ d
o oj 4 in
0 0 4 0
o O 4 4
(VJ 4 d o
O O 4 Oj
J N O (Vj
O o (Vj 4
©004
O) 0 0 4
o m d d
4010) 4
0 4 0-0
(Vj o) o Oj
oj o o o
4 O) o o
4 O) OJ d
4 4 in O)
d O n N
4 OJ 4 O
O (Vj UJ O
(VJ 4 4 O
O 4 O' OJ
o 4 4 in
Oj x O O'
Ol 4 Oj 4
O O O O
< CD O O
o o o o
in in in in
O) O) O) O)
a n <
4 ® <
o oj in
0 4 0
® 4 ©
0 4 0
Ndn
0 4 4
o © ©
O OJ (VJ
N- O (VJ
0 0 4
4 O' 4
0 0 4
or*-®
0 0 4
o o ©
4 o OJ
o o o
OJ 4 o
(Vj in ©
4 4 4
4 UJ N
4 4©
d © o
4 (VJ ©
© (V 4
OJ 4 4
0 4^
©44
O- d 4
0 4 4
f- o o
© Oj OJ
© © O
UJ u. O
o o ^
in in in
N- O (VJ
© (VJ 4
0 0 4
0 0 4
mod)
0 4 4
in n o
O O (VJ
O o o
o o o
O Oj 4
4 in 4
o o
OJ 4 o
OJ UJ o
4 4 0
4 O' OJ
4 4 in
>0 0 0
4 OJ 4
o oj in
OJ 4 4
0 4 4
0 4 4
—> >o o
4 4 Oj
in in oj
oj cc <4
o r- o
o <
> OJ
> OJ
o oj 4
0 0 4
©04
O Oj d
0 4 4
o o o
—« oj m
o o _
4 0 0
o o CD
OJ 4 4
oj in r-
4 4 0
4 UJ O
4 4©
d © ^
4 OJ O
O OJ d
OJ 4 o
0 4©
©40
indo
4 4 4
o- © o
O Oj OJ
O © OJ
0 0 4
oj d 4
in 4 4
o r- d
4 0 4
d O O
in O (Vj
ON O
4 0©
Ol/IN
OJ O 4
o o o
4 in d
a cc <j
— — o
(VJ uj o
4 4©
4 O' OJ
4 4 n
d © O
4 OJ 4
o oj in
OJ 4 4
0 4 4
0 4 4
O' d ©
4 4 OJ
N O OJ
© Oj 4
0 0 4
0 0 4
OJ O d
o in 4
d N- o
O O OJ
O O O
o o o
o o ^
4 o in
o d f«-
OJ o o
oj o o
4 0©
4 o Oj
4 4 in
d © O
4 (Vj 4
© © o
Nit?
o o ~
in uj x
04 ©
©40
O d O
in 4 4
p» © ©
O (VJ OJ
o o OJ
0 0 4
d 4 4
o in 4
d N- d
0 0 4
O O ©
O O OJ
o 0 - ©
4 0©
odd
oj o d
OJ O N
4 0©
4 0 0
4 4 ©
d © O
4 OJ 4
o oj d
OJ 4 4
© 4 UJ
© 4 4
OJ d ©
d 4 OJ
N O Oj
© Oj 4
o O ©
< ® U
dinddddddi/'dddddddini/'irdi/'i/'di/'dirinini/i
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 17
351
n lj « n
'C OD «J
u. o aj -j
coinoo
-* CD U. O
<r n cr> m
O o o CD
si n cd co
>* Q r^~ O
OOl/ll/l
OOffi -J
o -» O' CO
r- uj uj
a o o d
u. u. *- ©
ns«o
n •} ui
o < in cd
O u. o ©
'OMD ^
— in <
o oo in u. ri
OQ(M(\JO
n«oocoo
O O >C U 111
H<nNs
u.ir hoo
r-r-aoor*-
O *-< uj O UJ
© < m m
u. u. u © ©
N U. UJ O CO
ID (T III lii iT
CM 00 C5 l*. o
o © o © o
< CD O O UJ
< < < < <
in in in in in
n n n n (f
cn in in in in
in
i —i
(0
3
4-1
O
<c
o
•3
u
CU U
M
O 0]
CO <
o a
44
QJ 0
rn
O'
n
co
CM
o
ac
in
O
•P (3
(\) P
in co
c
n
u
o
■p
w
•H
Cn
a
p
a)
T)
c
c
3
p
D
« 10
-H
0
r d U
M
^ W
0 ^
rs n
CD
c
§
>4
Q
O
©
o
©
o
©
o
n~ o
r c
o
— O
o
U »-
m o in
o u. 3 *—<
a © u a *: _j
.. © — ..on
o o o o o
z Z 2 Z 2
*: * *: * *
a a a: a a;
o o o o o
3 3 2 2 3
in in in in in
o
n
a
- x o
: uj h-
. z in i
z i
a —. >
o a i
u. a. ;
asaas
o o o o o
< < < < <
O A A A A A
> O © Z
j co 3 uj uj uj ui uj
ic a i x x x x
O A K K »- K t-
•—'ll*—.
*- K
K Z h 1
z a *-. x o
*-• o a u h
a u a z in
O A O A o A A
3
* a
o A
a aocor‘~cc©u.'»<i_) 0 ©r*-c;ccc'»u.'»'ca:©^iroou. 0 '
inococroouuj^ococo'r^in<'0'j«jaDr^cMconcra'f*'U.^fMin
uoincinivjconccoccoconcoscoinn-. ccro^to —'©>joo
4o4onmonoinoooino-jir4(\j-j omo-to^oinoo
©Ho^coiMonoQQjiQoo^^oO'j in c_> m —< —< © n m —.
ajniMno^ono^ojoojo^'najaj^'tajin^-tin'Oji-ji
n®o®Q04o®<HcocooHnnocou r)o®o®-j®ocj®
noinooM^run^no^onunninm-t 'fno(\j^inoN4o
•jooosfflwninoooo®oooo4oNoo©noooino
no4o^m-j«J4fvjMofu>t(\j^f\J44Minajooinajooino
o®<--<in4ino^onco®®nino<UHU.-'in®oo<-'-joffl
nin<tn>tin<to 4 o^^ino 4 -jo>t-jn 4 ->t>*ininorn«oinin
nuioo(\jnoaoi\joo40oo(\joO'} nHn®OHn®ou
4-<tojrMinin(MncM>tinnjin©infMinfMtM4 , in^-t©cM'OCM©cMfM
o^onajoo®o®n®n<jn®®o(\iH o^(MOocooo©'t
o4-o^4fv-Lnoooininin<Mninooin>r (\j-jinooot\joon
U'odoooQDooO'joujO'Jori-t^ MjincO'O^nino
rvj(\jninajo4-o-?o(\j-?aj-j{\j-toin-}-j in>jininino<t^sO(M
coooonco\o<^cO'rouoinouffl®HO u.ou.u®i\i<ffOcoH
oooini/in^no>fo^o^o4iro-jo 4-tM>tnj©>t«t>^©-^
QOQo<tcooooonovo©a'©inQ>j-in uajninomujino^
onoi\i4oi\j(\JoM4(M-tf\j >j (\j ^ o 4 in 4mnno4-j 404
■H®®ouoon4®®n®o®r)4ffio® ©>rooccrn-«orn>t
no4o4oo44inonoinon44oo iM-*<MCMinin^fM>a-in
©0ono«soo40in00QSo440 fflH®HuooH(*)n
(\joojn(\jinninMinono4orii\iininoin444(Min(M44in
n®®®nin®nin4o®<r-o©n®n u-^r->t>4‘oo—«in©
4>4inon^oininin4 , nin'jfonoinoin fM-r.r-4m(Mo.j>Trvj
oo4QH4QO4oujninoonH00N ©©O'-joocmcm©©
in(Min©r)<4ofv>4fvj<t<r^cMfM>jin4-o<r r»©^«j(M©^3incM©
n®n4ooNO(joino4oioo®in4in o®®^i\jo®u.»hic
ininin4n(\j40404040400-4-t4 (Min>t^^'Oo<t>t^)
o4oujr p ioir®OrH04oNoocouj(\i iMcoooncoco^co
(M^CM>J^©»tr)CM-tCM>t(M«tinin©(M^in 40 M(\I 400 M 40
00000000000000000000 oooooooooo
'Of*~ooo'<cDUOUJii.o^rMn^in>OA-coa' <®uouJUOHNn
'O'O'nNO'O'O'n'n'O'Of^r^r^r^r^r^r-r-f^r- r^r^r^r^r^r^mcococo
inininminininininininininininininininin inininininininininin
nnnnnnnionnnnnnfonnnnio nnnnnnnnrin
cnininininininininmininininincninininin inininininininininin
r^-cM-.cruii-f^a>rinr'-Hr', r-.couc<iinr^u«ior^r)4<iaccx'c
uj<nu.inu.o©n<ii.O'^f*-ouj<cy'fMUJUJCM'ncor^f**«-.»-icDUJUJ
inoooUUUU44OOUUU0®M440UUU —< CM © O CD L_ U.
noooNffinNffiHoonnHHioMfflnmu^ ® o o ® s to
OUUJOQins®4UJUJHin®niLUJU'00(M®0004UJUJ(7'QlL
l\JI , 0! , l(MJ(MO<Uir®l T IXO®0( r l®nO'®<(\JOM , )NN®HO
<-«0^oOU_OU.O 41MOU.U.UD® ® U O U It U U. 4 ® ® O Q U. U.
^couomocr^r-^ooor^iju^-.u.^o^cor^ncDina'ooou.u.in
-H(juj<nQu.souu<onHN43ujuj4u.ininQUJUJUJ®oinin
^-Hninuo'Cu«^n^®®oooNininn®in'4onrtin«®oo
40000UUUO®l04lLU.lLMJ004lLU.NU.OvONOOirO
inoooncDUj'£ia'-'4-con-.^.r^-HCDa'«oinnf^cDcDo-H-.inr^o
nUJU>4QMnij.QUJUJ4li.-'-4U®UUJCDin^MJUU.UMnU
inin-<in<r'U(Mnmf^-.c_)CDC7'onr*-r)r^oouJUjr)r-.u_ruvto-f
Ol\JOOUUU0O40OinuuU4<(M4UUU®O44-HUin0
cm© >t©(rr~r)f^^Hec^^ccii.roro(M©©©r^u.rnf*>0'cc<ca'inr*“in
ou<oinMnmuiuJ4®inoin®U4UQmnDnuju®u®u4
oNffio®®0'ffiQninou®4<®N®iL(M®ooHa(Mno<o
®(MO®UUUQO®®4U.NMn4® >J <h U. O U. U. 4 4 O 4 II O II
®OOMn®NN®Off'Of0Mi.U.O'4O©^MnUJ'f®OON^U,
®®UJ(jn^onu®uju®HU.Mj 4 uunshhuiuuoujo i u.
offiincc4®'n<MnMno'Uo®nin^inffl4ffi(MMi.u.s®ujo
0MOO0UU.D04 (\JOUJDUIlOOhOI/1QIl 0 44IMOUOU
ouorHNln^N®•40--<uJ'£)I)ffl^lnuJo^^^^4oln©^^'H
~<uj<4UJii.'-'--<inii_ooo-'incDf'-'Cooij-r^r^inh-ujinoi_>ujC7'0
•4ininM-«cocc^MM-.mr-«o'<3 <MnsooO'-®c>ss-'OOo
Uf r l-4UUU.UU.UJ(\JUJOU.UU.U.4CMinoinUU.D440>Jli.lLin
•4®-'®lMQinNOO-®U.U.nCD(7'-<0®NiJ>N-0-<-H-<-H7'l\JN
ino<Mvoinr^r^r^o>nuJUJQ^—»inuJOO'tr^cEininuiJUJOu_Of^
ir©-innffi(MocDnMnoa®un^MU.<©ffi®m^in-(M<o
©C0 ^ 4UJUlLlLO(0(M4000U®00-LinuU 4 U 4 O U. U It
inin®onii.u.Noffluoa'u.inino®-4®Nsu.in(?'0®-<M*)N
©u4®u.inminuuujuua®nujuuj'4^Nu^uiuuJC®inir
(MfMinr*-0'0'0'-.r^h-coin<<<M<Mor*-r)ncoco^©r^r^no<ujuj
ooooooooooooooooooooooooooooo©©
•4in®N®(><fflU0UJUOH(Ml r l'4®®N®0<ffiU0UJU.O^<'J
QCCCa0<X)O0(X)CC<X)<X)COCCCDO'O'O'O'O'O'O'O'O'O'O'O'(7'O'O'O'^^*t
ininininininininininminininininininininininininininininininin
nnnnnnnnnnnnnnmonnnnnnnnnnnnnnn
ininininininininincnincninininincnininincnininincnininininincn
•— cm m ^ in
*
o
® (MU. I U tt ®
O a 4 ® K MO
O © © © 4 - c u.
O ® ® CD >H Q ro
u. u ® -o u in o
®N®Hh(MO
UOOOffll/IU
O' © © CO O' U. ri
r» co uj uj o o in
OhME(Oo4
Q (VI O o -too
P~- •—< -4 © O M >—«
ou4uuuin
uj o- n in ® 4
UO4O40U.
(O ffl ^ O O h ffi
inuuui 4u h
«-• in m in m < in
a ^ >4 © © u_ u_
u O' o o - > n
—. vo uj uj uj cd in
UMOMnCMO
It H Wo o U. u.
n o ® ® o n it
N 4 ®UJ 40 ^
O in CD r-* M CD CD
II (\J 4 O O U U
®0®0-hCD^
m o u u r- o
^ ro in in n © cd
u_ 4 o © © in in
h- o © oo co in co
O O 4 O O IT
o ~ o —• ~ li. ©
o o © o © o ©
cn in <c ® o
<<<<<<<
in in in in in in in
rn m m m m n m
in in in in in in in
Page 18
352
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
A CONSUMER COMPLAINT
Mr. Maury Goldberg
MiniMicroMart
1618 James St.
Syracuse, NY 13203
Dear Mr. Goldberg: Dated: 78 May 2
We have received the enclosed request for assistance from
one of our readers regarding an order placed with you. Since
the complaint seems reasonable enough on the surface, we felt
it would be in his interest as well as that of the home comput¬
ing community as a whole if we inquired on his behalf.
Enclosed you will also find a copy of Dr. Dobb’s policy
statement regarding consumer complaints. May I expect a
reply from you within three weeks of the date of this letter?
Thank you for your help in making the home computing
market a pleasant one for all concerned.
Sincerely,
Tom Williams
Editor
Dear Dr. Dobb’s, Received: 78 April 28
I’m writing in hopes that you can help me resolve a prob¬
lem which exists between myself and MiniMicroMart. I had
hoped that it wouldn’t get this far, but it appears that I’ve
done all I can and it’s time for outside help. I’m hoping that
you can aid me.
On January 5,1978,1 sent an order for three circuit boards
and some documentation for a total of $84.85.
I received a package from MMM within two weeks. How¬
ever, it was only a partial shipment. They showed one board
(their #CMOD 8-2P-100) as backordered, with estimated
delivery of “Indefinite approx. 4 weeks maybe the 8-22 bd.”.
This statement was on their work order/packing list, also
showing my invoice #8222, dated January 12, 1978. There
was no definite shipping date as required by Federal Trade
Commission mail order rules, no offer of refund and no post¬
age paid reply medium, also required by the FTC. Oh well I
thought, two out of three isn’t bad, and I settled down to wait
four weeks for the third board.
Unfortunately, there was another problem with that ship¬
ment. I had ordered their MOD-8 system manual that goes
with the boards I purchased. I found however that the MOD-8
applies only to 8008 based computers, so I sent it back to
MMM, asking that it be exchanged for their 8080 manual
(this request, along with the 8008 manual was sent the day
after I received the shipment containing the boards and man¬
uals). At the same time, I ordered a copy of their Monitor-80
program listing, enclosing a check for $6.00 to cover the cost
of the Monitor and shipping on both the Monitor listing the
8080 manual. The check was cancelled (so they obviously
received the MOD-8 manual and Monitor-80 order) but there
was no sign of the documentation, much less the board.
After 45 days (no FTC acknowledgement of my order,
no backorder notification, no offer of refund, no postage paid
return medium) I wrote, asking what had become of my Mon¬
itor, Manual and circuit board. No response.
One month later, 12 weeks since my original order, I wrote
once again. No response.
Two weeks later, I wrote again, this time sending the letter
Certified mail, with a Return Receipt, informing them that if
I didn’t hear from them, I was going to file a formal mail
fraud complaint against them with the FTC. The Return Re¬
ceipt came back, but nothing else. Apparently they aren’t
afraid of the Federal Government.
So as it stands, it has been nearly four months since I or¬
dered three circuit boards and three pieces of documentation
and all I have is two useless boards and one piece of data, and
a large bill for envelopes and postage.
I have contacted the FTC for a copy of their complaint
form, but as we know, the wheels of justice turn slowly, so
I am turning to you for help, Dr. Dobb's.
I know that your world is very busy and that you have your
hands full most of the time with the Journal, but I think you
would be doing a service, not only for me, but for all comput¬
er hobbyists if you would check this out and see what’s with
this company.
It’s bad enough that I’ve wasted four months on a company
with policies like those of MiniMicroMart, but I think that
worst part of this entire episode is being totally ignored by
a company which takes your money and delivers very little.
A company which also apparently views government regula¬
tions with disdain.
I should add, as a footnote, that I’m not interested in a
refund, I want the circuit board and documentation I paid
for.
Thanks for your time, 2005 Whittaker Rd.
Robert J. Retelle Ypsilanti, MI 48197
Editor’s Note:
Mr. Retelle eventually received his documentation but never
his third board. Dr. Dobb’s has received no written response
from MiniMicroMart.
On July 26, Dr. Dobb’s contacted Mr. Maury Goldberg
by phone. We were informed that the company manufactur¬
ing the boards had gone out of business and that he could
only offer Mr. Retelle a refund. -TRW
NEW GRAPHICS SOFTWARE FOR SWTPC
News Release Received: 78 April 20
GRAPH #1 and GRAPH #2 are utility packages enabling
convenient use of the SWTPC GT-61 graphics display with a
6800 computer. GRAPH #1 is for use with a machine language
program while GRAPH#2 is for use through SWTPC 8K
BASIC version 2. When using GRAPH #2, the user can
program the GT-61 display directly from a BASIC program
without any machine language programming.
Both versions can display, as well as erase points, lines, and
the complete upper-case ASCII character set. Additional
capability for user defined characters (such as chess symbols,
or even space ships) adds to the ease of use and versatility of
GRAPH. Each package is priced at $5.50 (for paper tape), or
$6.50 (Kansas City Standard Cassette) postage paid. Package
includes either paper tape or cassette, and a 22 page instruc¬
tion manual with sample programs and a full source listing
of GRAPH. Contact: Applied Microcomputer Systems, Box
68, Silver Lake, NH; (603) 367-8004.
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 19
353
THE LAST
OF THE FIRST
BY AUBREY DAHL
The Univac II was a marvelous collection of5,200 vacuum
tubes, 18,000 crystal diodes, 184,000 magnetic cores, hun¬
dreds of feet of plumbing, and countless miles of wires. It’s
a wonder that it worked at all; but work it did - for more
than 18 years.
The year 1958 was not exactly a banner year in the course
of human events, but it did usher in a computing classic when
Sperry Rand first presented the Universal Automatic Com¬
puter Model II (Univac II) to the world.
It was not only one of the most powerful computers of that
time, it was a veritable workhorse, persevering in varied en¬
vironments on many different applications, and working on
and on over the years far beyond the time of its expected
obsolescence.
But, inevitably, even reluctantly, the end came.
What is believed to be the last existing functional Univac
II in the world finally stopped reading, writing, and comput¬
ing this March when it was retired after more than 18 years
of reliable, sometimes even incredible, service.
The last 13 of those 18 years were devoted to the proces¬
sing of accounting data for Computer Data Corp. an enterpris¬
ing Gardena, California service bureau, where the first genera¬
tion machine was kept alive with third generation software
developed by the firm.
Univac II was able to support the accounting needs of an
extraordinary number of Computer Data customers, more
than 1,000 who probably didn’t realize or care that their
work was being done on the clanking antique.
Computer Data’s president, Thomas Pryor, bought the
machine from Pacific Finance in Los Angeles in 1964 when, at
a youthful 5 years old, it already was obsolete. But the price
was right and Pryor had a need and a fondness for the won¬
drous instrument.
Reprinted With Permission of DATAMATION © magazine.
©Copyright by TECHNICAL PUBLISHING COMPANY,
A Division of DUN-DONNELLEY PUBLISHING CORPORATION,
A DUN & BRADSTREET COMPANY, 1978-all rights reserved.
The cost of the computer was minimal compared to the ex¬
pense incurred during installation. Much larger in size than an
IBM 370/168 and less powerful than a present-day mini
(in fact, it is being replaced by one — the Sperry-Univac
V76), the Univac II was moved by cutting out a wall in the
building that housed it, and carting it across town to Gardena,
where a building had finally been located that had a back door
large enough to accommodate its unwieldy size. It wouldn’t
have been much more trouble to disassemble, move, and re¬
assemble a two-bedroom house.
When Sperry Rand first built the Univac II, it was hailed as
an impressive achievement in the emerging science of auto¬
mated data processing. And, indeed, it was, even though only
about 32 were ever built.
Think back. 1958 was also the year of the hula hoop.
And it was only a year after the introduction of the
Edsel.
The Univac II had much greater speed (160usec add time
versus 525) and memory (10,000 12-bit words of core versus
1,000 words of mercury delay line) than its predecessor, the
Univac I, which is often acknowledged as the first commer¬
cial computer.
Characterized by tube technology, the II boasted more
than 5,000 vacuum tubes, or “valves,” uncounted miles of
wiring, an immense water cooling system, an enormous,
tricky console, and a central processor that was 9 feet high,
10 feet wide, and 14 feet long.
A Walk-In CPU
In fact, the cpu was so large that it had a door on it and
interior space enough for a person to stand up and move
around in it. The computer and its peripherals, which together
weighed more than 8 tons, required a room with about 2,000
square feet of floor space. Its water cooling equipment was
nearly as big. Input was in the form of !4-inch magnetic metal¬
lic foil tape on reels that weighed about 2Vi pounds — each —
and were, as one might expect, very durable. The foil tape is
Page 20
354
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park. Ca 94025
Number 28
no longer made, but the original tapes worked fine right up
until the end. When a bad spot appeared on the tape, it was
possible to simply punch a hole in it at that point and con¬
tinue to use it; the tape drives would skip over the hole.
The II was not basically a punched card machine, as were
most of its brethren. That magnetic foil tape was the input
medium, too. Data entry was done, as it had been on the
Univac II, using key-to-tape devices — long before the
Mohawk Data Sciences engineers and others put their minds
to the matter.
Unlike newer machines, Univac II had a radio speaker that
was used to “listen” to its operations when troubleshooting
the system. Any deviation in the sound of the noisy computer,
and the bug usually was spotted. Inventive programmers
took advantage of this feature, in dull moments, and wrote
routines to make it play music. What modern day machine
would be able to sing “Auld Lang Syne” at its unplugging
ceremony as the II did?
According to various users of the old machine, it was the
most complicated and overdesigned piece of equipment
ever built — and one of the most dependable.
It was in 1958 that the first U.S. earth satellite, the
Explorer I, went into orbit and discovered the Van Allen
radiation belt circling the globe. Globe? That same year,
another space probe, the Vanguard I, determined that the
earth is slightly pear-shaped.
And Tim Tam won the Kentucky Derby.
Other users of the Univac II system included the U.S.
Navy Electronics Supply Office, the Department of Agri¬
culture Commodity Stabilization Service, U.S. Steel, Metropo¬
litan Life, and Pacific Mutual Life.
These organizations bought their systems new at a price of
around $114 million each. Tom Pryor bought his secondhand,
after it had been used for five years by Pacific Finance. He
estimated that with knocking out a building wall, moving, and
the setting up — which included installing an $80,000 water
cooling system — the machine cost him $250,000. That’s
about $20,000 a year for 13 years service he’s enjoyed — dirt
cheap.
The “high speed” printer that worked with the computer was
actually a Univac I device that was five years older than the
Univac II. It was capable of a then-incredible 600 lines per mi¬
nute on alphanumerics and was good for 8001pm when pushed
a little. It was still capable of this performance at the end.
Photo courtesy Sperry Univac Corp.
Number 28
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 21
355
The Software Lives On
The programming language used with the computer was,
appropriately enough, machine language. But the third genera¬
tion software developed by Computer Data over the years
enabled Univac 11 to perform accounting applications that
included payroll, accounts payable and receivable, invoicing,
and inventory control in a kind of “pipelined” batch mode.
Computer Data had developed, among other functions, a
monitor that allowed each customer’s applications to be
handled separately, but processed all like operations sequenti¬
ally in what might be called a “sub-batch.”
Although all the accounting programs are integrated with
each other, they are structured into standalone modules. The
specific requirements of each client are accommodated by the
coding of selected options in each module. These options are
recorded by entering what is equivalent to a company profile
on each firm whose work is to be processed. The programs
then perform as if they are custom programs especially designed
for that particular company, except that all of the invoicing
for all of the clients is done in one pass, then all of the ac¬
counts payable, etc.
Because of the modularity, a user could begin with less
than the full system and know that when he developed the
need and was ready for it, the expanded system would be
available to him. In a way, the concept was a cross between
tab processing techniques and batch processing. Yet it was
highly efficient in that, unlike batch or even multiprogram¬
ming in batch, it avoided continual loading and unloading of
programs. And of course the machine was built long before
multiprogramming was introduced.
The software has been converted to the Sperry-Univac
(nee Varian Data Machines) V76, and will be made available
to installations using Varian computers in accounting applic¬
ations — like an old man teaching his grandchildren a few
tricks. All of the accounting systems will be offered by Com¬
puter Data; they may be offered by Sperry-Univac’s Mini-
Computer Operation as well.
The U.S. was approaching the end of a decade that had
been relatively calm and peaceful, even though controversy
continued to flare over the continued development of nuclear
weapons. The so-called minorities were asserting themselves
in a way that would ultimately result in the publication of
a book named “Roots ” and a new awareness of human legacies.
The machine was an incredibly reliable worker from its
beginning. “It had only two down times of more than eight
hours in 12 years of operation,” said Pryor.
Through Fire and Flood
But those down times were certainly singular. In one in¬
stance, the machine began to function sporadically and thor¬
ough troubleshooting failed to turn up the cause of the mal¬
function (the computer wasn’t operating well enough to exec¬
ute the fault-finding routines).
Then someone thought he smelled smoke coming from
the top of the cpu. He climbed a ladder (remember, the cpu
is 9 feet tall) and found that there was cable erosion from
what he later called “tired insulation” — the cable, which had
been about a full inch thick, had frayed away over the years
to a 1/4-inch strand. Still the machine had run on. And so
the cable was cut and spliced, fresh insulation material was
wrapped around it, power was turned back on, and the Univac
II again operated with its customary reliability.
Arnold Palmer was the PGA’s leading money winner in
1958 with $42,507. Skirts were getting shorter and the nuc¬
lear powered submarine USS Nautilus made the first under¬
ice crossing of the North Pole on its way from Hawaii to
Iceland.
Another time at Computer Data the big machine went
down due to a plumbing problem. When the door to the main¬
frame was opened, water gushed out onto the floor.
The computer, Uniservo II tape drives, and power supply
all were cooled by a system that pumped water chilled to 50°
at a rate of 130 gallons a minute through copper piping. One
of the pipes that ran under the floor of the computer had
sprung a leak and water was jetting into the air like a small
geyser. The first step taken was to cover- up the leak with what¬
ever material was at hand - “keep operating” was the watch¬
word.
Water or no water, only after the shift was ended was the
extent of the damage surveyed. The floor was soaked and the
drainage hole under the floor of the cpu was under water.
There was water, water everywhere. An ordinary hand pump
was purchased from a nearby builder’s supply outlet, hoses
were attached, and the pumping proceeded. Fans were turned
on and placed to help the moisture evaporate. And in a matter
of hours, the job was finished.
Almost. When the Univac equipment was moved in, an 18-
inch-deep trough had been dug in the cement floor between
the main frame and the console to hold the cables connecting
them. The trough had been covered over with fitted wood
planking. When the cover was lifted, the trough was found
to be brimming with water, the cables completely inundated.
The machine had run in spite of this. And there wasn’t a
single short circuit in the system.
Succumbing to Old Age
Richard Means, Computer Data’s engineer who watched
over the Univac II for the past 13 years, and who worked for
Sperry Rand on a similar machine for three years before that,
said that it was a “phenomenal” computer in terms of depend¬
ability.
“I have taken components out of it for maintenance or
whatever and it just wasn’t supposed to keep on working,
but somehow, it did. It made some kind of inner adjustment
and stayed on. Incredible!”
However, Means added that each morning he came to work
during the months before the computer was phased out, he
kept his fingers crossed and said a little prayer.
To help maintain his machine, Pryor bought Univac com¬
ponents as spare parts when other machines came to the end
of service over the years, and kept them in rented space in a
warehouse next to his company. The warehouse has become
an archive of first generation computer hardware.
President Eisenhower signed the Presidential Pension Law
in 1958, and sent Vice President Nixon on a good-will tour
of South America, where he was mobbed in Caracas, Venezu¬
ela.
And the Supreme Court reordered school integration in
Little Rock, Arkansas. The more things change, etc.
Page 22
356
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
A change in business requirements in the mid-1970’s
and the continuing growth of the company led Computer
Data to the installation of an on-line system that could also
continue the firm’s time-tested batch operation.
Cost considerations and performance were major factors
in the decision to make the conversion to the V76 mini¬
computer, which is currently priced at about half of what the
secondhand Univac II had cost and provides a great deal
more capacity, speed, and power.
The V76 minicomputer has two 64K 16-bit memory
modules. The mini has semi-conductor memories instead of
core, and two 92mb discs. According to Pryor, the continuing
drop in the price of discs was another reason for the conversion.
Another cost factor was the electricity bill. It was running
about $2,500 a month, with the Univac II accounting for about
80% of it. When the V76 was added during the changeover,
Pryor said that he hadn’t noticed an increase of even $100
in the monthly bill. Now that the V76 is being used
exclusively, the savings are, at the least, substantial.
There were other, more particular, grounds for making the
change. Even with the extensive spare parts inventory,
maintenance grew increasingly difficult. And qualified techni¬
cians understandably became scarce.
Pryor explained that engineers trained in tube technology
for computers had become a vanishing breed because tube
logic had not been taught to undergraduate engineers in recent
years. Thus, as the need for a certain proficiency diminishes,
so does the proficiency, itself.
1958 was the first year that airlines carried more trans¬
atlantic passengers than ships and the year of the first jet
service across the Atlantic, by BOAC. Charles de Gaulle
became the President of France, and President Eisenhower
sent 5,000 Marines to Lebanon.
And the John Birch Society was founded.
And Althea Gibson repeated as national woman’s tennis
singles champion at Forest Hills.
Scrap or Souvenirs?
There is, of course, a nostalgic concern that the last
functioning Univac II has been consigned to history. When
asked why he had used the old workhorse for so long, Pryor
answered, “Because I owned it and it worked, and I wanted
to wait until minicomputers became usable and could provide
the right kind of accounting software support to go with our
own system programming.”
The ultimate disposition of the venerable computer is
still a matter of some conjecture. Pryor thought he might
rent warehouse space for it and the spare parts and preserve
what is now a relic for future interest, if he finds it
economically feasible.
On the other hand, he might, as he said, just save some of it
and sell the rest for scrap metal or souvenirs.
Dick Means had some thoughts on that subject. “The
Varian operation undoubtedly will bring in new business
with its advanced technology, but it wasn’t that the demands
were too great on the Univac — it was just over the hill.”
He smiled. “As for reducing the machine to scrap, you have
to remember that it’s Mr. Pryor’s baby — he could never watch
anyone take a hammer to it.”
The Pioneer moon rocket was launched in 1958. It didn’t
reach the moon but it achieved an altitude of 79,000 miles,
30 times as high as any previous man-made object.
The Univac II family set its records as well. Its last member
was operating productively 20 years after the series
introduction, its meter having recorded 43,219.9 hours of pro¬
cessing, 79,637.1 hours of being powered up. Those marks
may never be equalled.
TURTLE’ ROBOT FOR HOME COMPUTERS
News Release Received: 78 May 8
The Turtle is a small home robot invented by William D.
Hillis, a senior at MIT. The Terrapin™ Turtle is believed to be
the first commercial offering of a home robot ready for sale.
It can ‘walk,’ ‘talk,’ ‘blink,’ ‘feel,’ and draw,” says Dan Hillis.
Hillis is affiliated with MIT’s Artificial Intelligence Laboratory
which has used types of “turtles” in various projects.
The Turtle acquired its name because it is approximately
the size of a box turtle, consisting of a chassis topped by a
hemispherical dome 3 Vi inches in radius. The Turtle has two
large wheels and is capable of moving six inches per second. By
turning the wheels in opposite directions, the Turtle can be
made to rotate exactly on the spot. Other endearing features
of the Turtle include beeping its speaker and flashing its lights.
The Turtle can also “feel” and “draw.” The former is ac¬
complished by using its dome/shell as a touch sensor so that
the Turtle “knows” when it bumps into an object. To draw,
the Turtle lowers a pen from its chassis and moves. With these
two capabilities, the Turtle can map rooms by entering them,
bumping into the objects within them, and storing the config¬
uration in computer memory. Then the Turtle can let down its
pen and draw a rough representation of the floor plans.
The Turtle has lights for eyes and a speaker to emit sounds.
It requires a parallel interface: one compatible with an S-100
bus is available as an accessory. Each Turtle comes with ten
feet of cable and may be purchased either as a kit or fully as¬
sembled. Each kit comes with a tested, 20-page instruction
manual.
Brochures are available. The Turtle sells for $300 in kit
form and $500 assembled. The interface is $40. Contact David
McClees, Terrapin, Inc., 33 Edinborough St. Sixth Floor,
Boston, MA 02111; (617) 482-1033.
Number 28
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, Ca 94025
Page 23
357
BY FRITS VAN DER WATEREN
van't Hoffstraat 140
Haarlem, NL 2014 RK
The Netherlands
LISP is an interactive list processing language and very suit¬
able for microprocessors. LISP is very easy to learn and has a
very simple syntax. It is very easy to write recursive programs
and functions, because the system will stack all returns and
intermediate results. When you want to define, for instance,
the function for N!, in LISP this would look like:
(DEF FAC (N)(COND ((EQ N 0) 1)
(T (TIMES (N (FAC (MINUS N 1)))))
) )
“BASIC minded” people would find this an ugly notation, but
in fact it is very well structured.
As you see, we define the function FAC of a variable N.
The function-body is a CONDitional expression, where N is
tested to be EQual to 0, then the result is 1; else (T) the result
is the product of N and the ‘FAC’ of N — 1.
As you see, we recursively call the function FAC again,
where N is assigned to N — 1 and so on. As I said, the system
will stack all the intermediate results. This is done on a so-
called Association list, because all structures in LISP are lists.
Not only data is represented as a list structure, but programs
and functions are also lists. This is one of the powers of LISP.
And by means of the list notation you can directly see the
internal structure of a list.
This interpreter recognizes “inner list” notation only, but
it is very easy to write a program, in terms of LISP, which
recognizes both “inner-” and “outer lisp” notation. We could
write:
(DEF lISP2( ) (PROG (A)
START (TERPRI)
(TEREAD)
(PR I NT(QUOTE :))
(PRINT(C0ND((AT0M(SETQ A (READ)))(APPLY A (READ) NIL))
(T (EVAL A NIL)) ))
(GO START) ))
When we now call: (LISP2). We are in the just defined higher
level interpreter, which has “: ” as a prompt (the input routine
READ will still print so we get : * as a prompt now) and
the system will now evaluate both:
car( (a b) ) which gives A and
(car(quote (a b) )) also giving A.
In outer lisp notation the system does the qouting for you.
For completeness I shall give the definition of DEF:
(PUTPROP (QUOTE DEF)
(QUOTE (LAMBDA (L A)
(PUTPROP (CAR L) (CONS LAMBDA (CDR L)) EXPR )))
FEXPR)
We can now define a function by:
(DEF function-name (list of parameters) (function body) )
The basic LISP interpreter consists of a READ. EVALuate
and PRINT cycle, and will therefore directly execute the
expression, the user has typed, and print the result. When you
type, for instance:
(TIMES-3 4)
The system directly responds with: -12.
It is not my intention to give a complete description of the
language, because a good description is too long for just an
article. But there are some good books about LISP (see Refer¬
ences).
This implementation of LISP is a version which is called in
the literature LISP 1.5. That is standard LISP, or LISP 1, with
two extensions called the PROG-feature and the FUNARG-
mechanism.
Features of This Implementation
• The interpreter uses 4.5K bytes, including the initial
OBLIST, and runs very well in a system with 8K bytes.
• Non compacting garbage collector.
• Advanced I/O capability.
Implemented handlers are:
TTY handler with an ACIA.
READER handler with a PIA (A).
PUNCH handler with a PIA (B).
And it is very easy to extend this by patching the device
table with an address to user written handlers.
• Very free input format.
• Easy error recovery by means of BACKSPACE, DELETE
and CANCEL.
• Automatic storage allocation.
• Extended error messages.
• The interpreter recognizes ‘inner lisp’ notation.
Page 24
358
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
Brief Function Description
Arithmetic functions
Elementary functions
(CAR X)
(CDR X)
(CONS X Y)
(QUOTE X)
(RPLACA X Y)
(RPLACDX Y)
I/O functions
(READCH DEV)
(READ1 DEV)
(READ DEV)
(TEREAD)
(PRIN1 DEV)
(PRINT X DEV)
(TERPRI DEV)
(OPEN DEV NAME)
(CLOSE DEV)
Predicates
(ATOM X)
(NUMBER X)
(NULL X)
(EQXY)
(GREATER X Y)
(COND (A B) (X Y))
(LIST A BC.. .Z)
(EVALX Y)
(APPLY XYZ)
(PROG (A B....)
L (statement 1)
(statement 2)
)
(GO L)
(RETURN X)
(FUNCTION X)
(ALIST)
value is the first element of list X.
value is the remainder of list X.
value is the list: (X . Y)
value is X literally
replace the ‘CAR-part’ of X by Y;
value is X.
replace the ‘CDR-part’ of X by Y;
value is X
read one single character from ‘DEV;
value is this character.
read an atom; value is this atom.
read an S-expression; value is this
expression.
flush the input buffer; value is NIL.
print atom X; value is NIL.
print S-expression X; value is NIL.
print a CR and LF on DEV; value is
NIL.
open a file on DEV with NAME as
file name.
close file on DEV.
if X is an atom, value is T else NIL.
if X is a number, value is T else NIL.
if X is NIL, value is T else NIL.
if X is the same as Y, value is T else
NIL.
if X is greater than Y, value is T else
NIL.
If A is not NIL then B is evaluated;
else if X is not NIL then Y is evaluat¬
ed; else NIL.
The result is a list of all its evaluated
arguments. The number of arguments
may be infinite.
Evaluate X with Y as association -list.
In fact this is the LISP-interpreter
itself.
Apply the argument Y to the func¬
tion with Z as initial association-list.
With this function we are capable of
writing programs in LISP. The first
argument of PROG is a list of vari¬
ables used inside the PROG, and the
remainder is a list of labels and state¬
ments.
Goto label L (literally)
Return from a PROG with the value
of X.
This is a quotation for functions,
return the current systems associa¬
tion-list.
(PLUS X Y)
(MINUS X Y)
(TIMES XY)
(QUOTIENT X Y)
value is X + Y
value is X — Y
value is X * Y
value is X/Y
Some miscellaneous functions
(SETQX Y)
(PUTPROP XYZ)
(GET X Y)
(SASSOC X Y)
X is set to the value of Y; this is also
the value of this function.
The property-list of atom X is
extended by property Y under an
indicator Z. If the indicator already
exists, then its property is altered;
value is Y.
Get the property saved under the
indicator Y from the property-list of
atom X.
Lookup X on the association-list Y,
when found return its value; else NIL.
How to Obtain This Implementation
Send an International Money Order to:
F. v. d. Wateren
van’t Hoffstraat 140
Haarlem, NL 2014 RK
The Netherlands.
Costs:
• $ 10 . -
• $25. -
• $30. -
• $12.50
• $32.50
for an object papertape in SI-FORMAT complete
documentation, and a listing of the I/O package of
LISP.
for an assembler listing with symbol table and the
macro generation for the OBLIST (in GPM)
for the above mentioned two items.
for cassette tape, Kansas City standard, 300 baud,
including description and I/O listing.
for cassette and complete listing.
References
1. Berkeley, Edmund C., and Daniel B. Bobrow, The Programming
Language LISP: Its Operation and Applications, MIT Press:
Cambridge, MA, 1966.
2. Friedman, D.P., The Little LISPer, Science Research Associates:
Palo Alto, CA, 1974.
3. Siklosky, Laurent, Let's Talk LISP, Prentice-Hall: Englewood Cliffs,
NJ, 1976.
4. van der Poel, W.L., The Programming Languages LISP and TRAC,
T.H. Delft: The Netherlands, 1972.
5. Waite, W.M., Implementing Software for Nonnumeric Applications,
Prentice-Hall: Englewood Cliffs, NJ, 1972.
6. Weissman, Clark, LISP 1.5 Primer, Dickenson: Belmont, CA, 1976.
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 25
359
FORTH DUMP PROGRAMS
BY JOHN S. JAMES
1090 Miller Ave.
Berkeley, CA 94708
Here are a couple short examples to illustrate programming
in Forth.
Forth is a stack-oriented programming language which is
also its own operating system. Typically the complete Forth
system fits in only 6K bytes of code, which includes the Forth
compiler, a run-time system including I/O drivers and virtual
memory, a text editor, plus an assembler, which is (optionally)
used for writing new I/O drivers or time-critical code which
must run at full machine speed. Forth object code is very
compact and the system is interactive, yet run-time speeds
can be as little as 30 percent slower than machine code (100
percent on 8-bit micros). Typical hardware is 16K bytes
and a CRT; for serious development work, a floppy or other
random access mass storage for source programs is necessary.
For more introductory info, see my article in the May, 1978
issue of Dr. Dobb’s.
The Forth system is like a root of a language which grows
toward any application area for which it is used. Forth
programs consist of short (usually one to five line) definitions
of new operations, which then become part of the language.
Each large application program is really a special-purpose
language, greatly facilitating modification. Because object
code is so compact, any general purpose operations (such as
the examples below) can be added permanently to the
language. Then they are automatically available to be used
from the terminal as commands, or as instructions in other
programs; and they are used in exactly the same way in
either case.
Here is a Forth program to dump a specified number of
bytes from a given memory address:
: DUMP 3 F = 0 DO DUP I + \@ . LOOP DROP ;
Examples of its use, in decimal and octal:
8100 10 DUMP
32 0 114 31 214 6 18 11 140 6
8100 10 OCTAL DUMP
40 0 162 37 326 6 22 13 214 6
Most Forth systems can use any number base, even above
16, in which case letters after ‘F’ in the alphabet are taken
as digits. These number bases affect only the I/O; internal
computations are binary, so there is no loss of efficiency.
Forth operation names are separated by one or more
spaces. Names can be any length, and can include any combi¬
nation of letters, numbers, special characters, or even invisible
control characters. At compile time, the system first searches
the dictionary of operation names. If the character string is
not found, it tries to make a number out of it, using the
number base which is currently in effect; if this fails an error
message is given. Almost all of Forth, the system itself and
the user’s applications, is part of the dictionary.
In the example above, the first character string is (a
colon), which is the DEFINE operation. It sets up the
beginning of a dictionary entry for the next word, ‘DUMP’.
The definition is terminated by the semicolon.
‘3 F =’ sets ‘F’, which is the output field width, to three,
so that each number which is output will take at least three
spaces (plus an additional space between numbers). This is
done so that the output will line up well. Otherwise each
number would take as many spaces as it happened to require.
At execution time, the number three is pushed onto the
stack, then ‘F’ is executed. ‘F’ is a variable of type INTEGER,
declared by the system and used as field width by the output
routine. Forth users can declare their own variables of type
INTEGER, of other system-defined types such as CONSTANT
or ARRAY, or they can create their own user-defined variable
types.
Any variable of type INTEGER is really a Forth operation
which pushes the address of a location suitable for storing an
integer onto the stack. After ‘F’, *=’ is executed; it places the
second number on the stack into the address on top of the
stack; and then, like other Forth operations, it destroys its
arguments on the stack.
‘DO’ and ‘LOOP’ are structured looping operations. ‘DO’
takes an initial and a termination value from the stack (the
loop actually ends one before the termination value). In this
case, when ‘8100 10 DUMP’ is executed, the stack contains
‘8100’ and ‘10’ before DUMP starts to execute. ‘ 3 F =’ makes
no net change to the stack, but ‘0’ is pushed on before DO is
Page 26
360
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
executed, so DO sets up a loop of ten iterations (index values
zero through nine). ‘DO’ destroys its two arguments on the
stack, which then contains only ‘8100’.
Now ‘DUP’ makes a copy of what’s on top of the stack,
making the stack be:
8100
8100
‘I’ is an operation which pushes the value of the index of the
innermost ‘DO’ loop onto the stack. *+’ adds the top stack
values, replacing them with their sum. On the first iteration,
zero was added, leaving the ‘8100’ unchanged.
‘\@’, or BYTE FETCH, replaces the address on the top
stack value with the byte which was at that address. V, or
PRINT, prints the value on top of the stack, and then discards
it. Each time around, the ‘8100’ sitting on the stack is copied,
the loop index is added to it, and the byte at that address is
printed.
After the loop terminates, ‘DROP’ is executed. It throws
away the top stack value. This is to get rid of the ‘8100’, so
that DUMP does not leave garbage on the stack after it has
finished.
Incidentally, this program could also be written (a little
better) as:
: DUMP 3 F = OVER + SWAP DO I \@ . LOOP ;
‘OVER’ takes the second argument on the stack and (without
destorying it) pushes a copy of it on to the stack. After the
*+’ is executed, the stack contains:
8110
8100
(assuming that ‘8100 10 DUMP’ was executed). The rest of
the working of this program is left to the reader as an exercise
(SWAP reversed the top two items on the stack).
Here is a dump program which formats every 100 bytes
(if in decimal) into a separate block of print-out, with the
starting address printed on a separate line. (In octal, every
64 bytes is in a separate block, and similarly for other number
bases.)
: BYTEDUMP 3 F = OVER + SWAP DO
I BASE @ DUP * MOD 0* IF CR CR I . CR THEN
I \@ . LOOP ;
8000 140 OCTAL BYTEDUMP
17500
234 4 140 6 12 0 64 25 262 14 110 25 246 36 140 6 24 0 100 36
66 15 140 6 62 0 100 36 66 15 140 6 106 0 230 36 166 14 200 4
166 21 146 21 156 24 276 36 214 6 12 102 117 130 104 0 32 37 326 6
136 14 266 27
17600
42 37 356 27 200 37 214 6 6 107 105 122 115 0 142 32 326 6 140 6
36 0 64 13 140 6 37 0 64 13 214 6 3 102 131 105 40 0 162 37
326 6 22 13 214 6 4 104 125 115 120 0 376 33 326 6 202 14 44 31
2J36 21 136 14
17700
266 27 234 4 100 30 200 4 210 21 66 32
This program is similar to the example above, except for
the added second line. ‘I’ puts the loop index on the stack, and
‘BASE @ DUP *’ duplicates the value of the number base
currently in effect and multiplies, leaving the square of the
current base value on the stack, with the loop index value
below it. (‘BASE’, like ‘F’, is an INTEGER type variable
defined by the system, and used by the V output routine.)
Then MOD replaces those two numbers by their modulus,
which is zero if the loop index (which is the next address
to be printed from) is evenly divisible by the square of the
current number base; otherwise it is some non-zero value.
This is done because in Forth, structured conditional
instructions take zero as truth-value FALSE; any non-zero
value is TRUE. ‘0=’ tests the top of the stack for zero,
replacing it by ‘1’ if it was zero, by zero otherwise; i.e., ‘0=’
reverses the truth value of the number on top of the stack
(some Forth systems call this operation ‘NOT’).
Now ‘IF’ tests the top of the stack; if it is true (non-zero),
code following the ‘IF’ will be executed. (If false, code after
an ELSE would be executed, but the ‘ELSE’ clause is optional
and not used here.) In either case, execution continues after
THEN’.
In this example, if the address of the next byte to be
printed is evenly divisible by the square of the base, the
modulus is zero, which ‘IF’ would interpret as false. ‘0=’
reverses the truth value, and the code ‘CR CR I . CR’ is
executed in that case. This code does two carriage returns,
prints the address (the value of ‘I’), and does another carriage
return.
This program in object form takes 64 bytes; it can be left
as a standard part of the system or, if memory is very tight,
it could be loaded when needed. It can be used from the
terminal as a command, or as part of another program. ‘BYTE-
DUMP’ doesn’t care how its arguments get on the stack, so
they don’t have to be literals; the full power of Forth is
available to compute them.
This program is written in the Caltech version of Forth,
which is distributed by DECUS for PDP-11. Other Forth
versions use different names for a few of the operations, e.g.
the equal sign may be equality test, with an exclamation mark
used for the STORE operation, where these examples use
qual sign. Usually software is fairly easily transportable even
when the Forth versions have not been designed to be
compatible, using redefinitions such as:
But Forth versions on different machines can easily be
identical, so that software written on one machine can be
transported to others without change. Currently the Forth
Interest Group (787 Old County Rd., San Carlos, Ca 94070) is
developing identical implementations for several different
micros and minis, and the code will be in the public domain.
This paper hasn’t mentioned other features of Forth,
e.g. nesting of loops and conditional, recursive routines, easy
implementation of multitasking, tree-structured vocabularies,
or modular debugging. Forth is especially suited to real-time
control applications, to large projects, and to small machines.
Software development times are often a fraction of what
would otherwise be required. Today, access to Forth can be
hard to find (e.g. to my knowledge, the system used for these
examples is the only one currently running in Berkeley). We
expect increasing use of this language as it becomes more
available.
NOTE: For more information, see the newsletter Forth
Dimensions, published by the Forth Interest Group, 787
Old County Rd., San Carlos, CA 94070. Price is $5 subscrip¬
tion, $1 single copy.
Number 28
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, Ca 94025
Page 27
361
STRUBAL VS FORTH
Gentlepeople: Received 78 July 5
This letter was inspired by John James’ article on FORTH
in your latest magazine. (No. 25, page 21) I was very impressed
with the ingenuity of this system. It seemed very cleverly de¬
signed to get so much capability in such a small space. Unfor¬
tunately, I think that FORTH fails one of the primary tests
of a good programming language: readability. I feel that a
good language is designed to make programs easy to read
and understand. Easily read programs are easily debugged pro¬
grams. I was hard pressed to figure out that:
: POLY DUP DUP * 5 * SWAP 7 * -10
was the evaluation of the polynomial 5X 2 -7X-10. I think
that a language should express such a statement more like
the following form:
PRINT 5*X*X-(7*X)-10
which is much easier to relate to the task at hand. To under¬
stand the FORTH construction I have to think about stacks,
etc. and the internal representation of data. High-level lan¬
guages should insulate the programmer from such considera¬
tions as much as possible.
The illustration on page 24 is another example of the lack
of readability of FORTH programs. I doubt that any program¬
mer could quickly determine what this program does. I have
seen programs for the LIFE game in many languages, but the
FORTH example was by far the most obscure. No doubt
it is easier to use than assembly, but there has to be something
more readable. I think a well commented assembler program
would make more sense to the average reader that the
FORTH example!
I enclose an example of how I feel the example program
might be written. The language of my example is STRUBAL,
a language that J. Hemenway and I devised. A STRUBAL
eample appeared in an earlier Dr. Dobbs’ (no. 23). STRUBAL
exists as a full-compiler for 6800 systems. It runs in a min¬
imum of 16K bytes of RAM and requires mass storage. The
example compiled into 1888 bytes of object code, which
is considerably bigger than the FORTH code of 475 bytes.
However, the run-time package required by the STRUBAL
code was 3.9K bytes as opposed to the FORTH interpreter
size of 5 to 6K bytes. The STRUBAL assembly code file could
be readily optimized by a programmer knowledgeable in
6800 assembly language to remove 200 to 300 bytes. I feel
that program size (within reason) is not so valuable a measure
of language quality as readability, but STRUBAL and FORTH
seem to produce roughly equivalent load modules when all
memory-resident parts are accounted for. Since the STRU¬
BAL code is directly executed, it will be much faster than the
FORTH code, which must undergo some interpretation.
True, STRUBAL requires the overhead of multiple passes
through the source program, and it needs intermediate files,
but the end result is a program that both works and can be
read by someone else. The example program took me about
20 minutes to write and key in, about 8 minutes to compile
and run, and it ran the first time.
The example maintains two “universes”, each an array
with 25 rows and 81 columns. A “generation” is defined as
the conversion from the present universe to a new universe.
Lines 6-12 set up a random first universe. On average, half
the elements of the universe (called “cells) will have a star
0*’) in them (called “alive”). Lines 13 through 18 copy the
new unvierse back into the old and print out the universe as
the latest generation. Line 16 uses the STRUBAL string
capability to copy an entire character string at once. Lines
20-46 create the new generation. Lines 23-28 count the
neighbors of a given cell. As in the FORTH example, the cell
itself is counted. The STRUBAL keywod “XTRACT’Yemoves
a number of characters from a given string. Lines 30-38 deter¬
mine the state of a cell in the new universe. Note that a cell
counts itself as a neighbor.
The STRUBAL example is rather “self-explanatory” ...
and I feel that this is major strength. The STRUBAL compiler
is available from:
Hemenway Associates
151 Tremont Street
Boston, Mass. 02111
on Smoke-Signals, ICOM, SWTP Flex, and PERCOM disks.
A source-book which gives the entire source listing and com¬
prehensive algorithm descriptions of the compiler will be
available soon. Hemenway Associates markets an extensive
line of 6800 software, including a macroassembler, editor,
linking loader, and cross-assemblers for the 6502, 8080 and
F-8.
I feel that software writers should strive for readability
in their work. What good is a clever algorithm design if no one
can find if among the verbiage?
Sincerely, 148 Wood Street
Robert D. Grappel Lexington, MA 02173
OOOl
0002
0003
0004
0005
0006
0007
0008
0009
OOIO
0011
0012 .
0013.
0014
0015
0016
0017
0018.
0019
0020
0021
0022
0023
0024
0025
0026
0027
0028
0029
0030
0031
0032.
0033
0034.
0035
0036
0037
0038
0039
0040.
0041
0042.
0043
0044.
0045
0046
0047
0048
0049
0050
0051
* PROGRAM TO PLAY LIFE
* INITIAL GENERATION RANDOM
* 80 BY 24 MATRIX TO FIT CRT SCREEN
* INSPIRED BY FORTH VERSION IN DR DOBBS #25 PG 24
*
DSTRING B1(81. 25). B2(81.25)
FOR 1=1 TO 25
FOR J-l TO 81
STRING B2(J.I>=
IF RAND(I) LT 0 STRING B2(J.I>= *
NEXT J
NEXT I
LOOP PRINT ///, C793. NEW GENERATION'
FOR 1=2 TO 24
STRING Bid, I )=B2( 1, I >
PRINT ✓ ,XB1(2,I)
NEXT I
FOR 11=2 TO 24
FOR Jl=2 TO 80
NBRS=0
FOR 12=11-1 TO 11 + 1
FOR J2=J1-1 TO Jl+1
XTRACT TEST-1.B1(J2.12)
STRING IF TEST EQ * ' LET NBRS=NBRS+1
NEXT J2
NEXT 12
XTRACT TEST-1, B1< J1, Ill
* CELL WITH 2 OR 3 NEIGHBORS SURVIVES
* CELL WITH <2 OR >3 NEIGHBORS DIES
* EMPTY WITH 3 NEIGHBORS CREATES NEW CELL
STRING IF TEST . EQ THEN EMPTY
IF NBRS LT 3 THEN DIES
IF NBRS GT 4 THEN DIES ELSE SURVIV
*
EMPTY IF NBRS NE 3 THEN DIES ELSE SURVIV
DIES STRING B2<J1,I1>=' '
GOTO ELOOP
SURVIV STRING B2(J1,U)= *
ELOOP NEXT J1
NEXT II
*
INPUT /.'CONTINUE (Y OR N>?',XTEST
STRING IF TEST EQ Y THEN LOOP
STOP
END
Page 28
362
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
USE OF NOPCODES AS EXECUTABLE LABELS
Received: 78 April 7
Every microprocessor has one opcode defined as a “no¬
operation” (NOP), useful as a filler in program gaps or timing
loops. In addition, some micros have opcodes (defined or
undefined, the latter “illegal” and so not necessarily identical
in chips from different mask sets) that are executed without
causing any detectable change anywhere. These can be called
nopcodes. E.g., the 8080 and Z80 have 7 instructions ($7F,
$40, $49, $52, $5B, $64, and $6D) that move the content
of a register into the same register, and so are defined
nopcodes. Although they must now be the least-often used
opcodes in the 8080 set, they could be used as executable
labels for the next instruction. Such labels, although meaning¬
less to the CPU and with no effect on operation (except
timing), could be assigned meanings interpretable by
debuggers, relocaters and other programs. The information
content of the 7 “monops” (short for one-byte nopcodes)
is limited, but could be increased by using sequences of 2
(“monop-duos”) or 3 (“monop-trios”). For example, the
8080 could have 49 monop-duos and 343 trios. Since
interpreting logic could easily recognize solos, duos, and
trios, this would allow 399 different labels. If the 8080 NOP
(00) were allowed as the second and/or third element, the
total would become 511.
Although the 650X has no defined nopcodes, it now has
a large supply of undefined ones. (This of course will change
in the enhanced versions now in the design stage, but there
are thousands of systems now using the original design.)
It has 6 monops ($ 1 A, $3A, $5A, $7A, $DA, and $FA).
It also has 5 two-byte illegals ($80, $82, $89, $C2, and
$E2) that require an “operand” byte but make no use of it.
I think of these as “binopcodes” (nopcode plus one
“noperand”) or “binops”. Since the noperand can be any one
of the 256 possible 8-bit bytes, the information content of
binops is very large (and they would be simpler to interpret
than monop-duos or -trios). There are also “trinops” (e.g.,
the 8 illegals of type X! C).
Before going on, I should reply to the letter by Paul Schick
( DDJ #21), that is a strongly negative reaction to my article
on 650X opcodes (DDJ #17). Neither in that article nor in my
note in BYTE (2 (12): 72, 1977) did I advocate the use of
illegal opcodes as instructions. In fact, the whole point of
my legality-testing subroutines OPLEGL (DDJ #17 and
#19) and HYLEGL (DDJ #22) was to screen out illegals.
I presume that the 650X designers know very well what their
chip does with illegal opcodes (although they see no need to
document it!). I respect their decision not to support even the
illegal operations that might be somewhat useful. However,
designers are not endowed with divine omniscience and
infallibility. They can—knowingly—do something foolish,
or—unkowingly—do something wise. The point I am trying
to make in this note is that some nopcodes may be so useful
as programming aids that their retention as defined elements
in an instruction set merits serious consideration by designers.
I am presently exploring the implementation of 650X bin op-
labels, but this will require time and thought, so I am
publishing the concept in order to make it immediately
available to other programmers (and to designers).
In thinking over possibilities for scanning-debugging (of
which my program SIMBUG in DDJ #19 is a very primitive
example), it became increasingly clear that the superiority
of assembly langugae over machine language largely rests
on its much higher information content, especially in labels.
This makes assembly-language programs much longer,
somewhat more intelligible to human beings, and quite
unintelligible to the microprocessor. A fairly complex
assembler program is needed to translate them into machine-
intelligible form. The assembler also acts as a scanning-
debugger and as a program locating and addressing controller.
Labels play the major role in these useful activities with
the crucial symbol-table at the core of everything.
In the KIM-1 program SWEETS by Dan Fylstra (BYTE
3 (2): 62, 1978), there is an ingenious use of machine-
language labels. However, a Fylstra-labeled program is not
executable. Labels must be removed before execution, and if
there are execution bugs they may need to be re-inserted for
the program revision. This limitation could be removed by
using binop-labels. In fact, some problems of machine-code
relocation might be soluble by retaining at least some nop-
labels in the taped or disked programs, which could then be
address-corrected by a relatively simple program.
A special kind of labeling is also possible with legal
opcodes. E.g., a STORE instruction addressing a location in
ROM is in effect a NOP, so that both the ROM page and the
location on that page can convey information. Also, any
instruction that is unreachable in program operation could be
used to store non-program information (a trick used in my
subroutine BYTNUM, in DDJ #17, 1977. However, the detec¬
tion of and in formation-retrieval from such labels would be
less convenient than with monop- or binop-labels. A ROM-
trinop ought to use a STORE opcode normally rarely used in
working programs, to make detection easier (the page of every
such opcode would have to be checked to distinguish between
ROM and RAM), but would still involve more bytes and
execution time.
The conservative view of a microcomputer system is that it
should differ from large systems primarily in scale, in the way
that a VW differs from a Mercedes, and that there ought not to
be qualitative differences in hardware, software, or methods of
operation. Innovations should arise in the giant systems, and
then (to the extent that the micropocketbooks of micro users
allow) be copied at the lower levels. I prefer another analogy.
There are no elephants that burrow underground like moles or
can fly like bats, and downsizing to the level of insects allows
even greater diversification. Micro systems are going to be
individualized and customized in ways that would horrify
IBM, and some innovations at the micro level (most will of
course be failures) may well migrate upward.
H.T. Gordon University of California
College of Natural Resources Berkeley, CA 94720
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 29
363
MAKING A NEW case
FOR THE HEATH H9 TERMINAL
BY HOWARD L. NURSE
665 May bell Avenue
Palo Alto, California 94306
Copyright, 1978, Howard L. Nurse.
If one reason you invested in a computer is to take advant¬
age of word processing programs, a display restricted to upper
case is as useful to you as a one octave piano is to a composer.
Here is a simple method for converting the Health H-9 video
terminal to display lower case alphabetic characters.
After studying the circuitry, I found it would be easy to
modify the H-9 to include the missing characters. The key¬
board on the H-9 would be difficult to convert, but Heath
Fig. 1
Detail of H-9 Character Generator board showing lower case modifi¬
cation
Reprinted with permission from REMark Magazine, Journal of Heath
User's Group.
has provided a convenient parallel I/O connector on the rear
panel of the terminal, through which an external keyboard
having upper and lower case can communicate.
This article describes how you can add the integrated cir¬
cuits and keyboard to an H-9 to make it a full upper/lower
case terminal.
Circuit Modifications
A circuit diagram and parts list for the changes to the H-9
Character Generator Circuit Board are shown in figure 2. Two
integrated circuits, an RO-3-2513-/CGR-002 from General
Instruments and an SN74LS27, must be added to generate the
new characters.
The lower case memory, an RO-3-2513/CGR-002, has a
surprise in store for the unwary. For some reason (probably
perfectly logical) the addresses on the input of the CGR-002
chip are inverted with respect to its upper case twin. The H9
modification would have been simplified had the address
formats of the two character generator chips corresponded.
The General Instrument catalog lists a version of the 2513,
the CGR-005, which has correct address levels, but this device
is not readily available through mail order outlets. Fortunately,
the required inverted addresses are available on the inverted
Q outputs from IC202 and IC203. The outputs from the
character generator chips are directly compatible.
The outputs from the character generator chips can be
made active or high impedance, depending on the level of the
enable inputs on pin 11 of each chip. When pin 11 is low, the
outputs of the corresponding chip are active.
IC223, an SN74LS27 Triple NOR Gate, has been added
to the character generator board to select which chip will
be active. When bits 6 and 7 of the incoming ASCII character
are high, IC223 recognizes that a lower case character is pres¬
ent and enables the lower case character generator chip. At all
other times the upper case chip is enabled by the same IC.
Wiring the Two Integrated Circuits
The two new integrated circuits are piggy-backed onto host
IC’s on the Character Generator board. A photograph of a
modified board is shown in figure 1. I found the easiest way
to add the devices was to mount a socket on the original
chip, and then to mount the new IC in the socket. A total
of 7 external connections must be made to the character gene-
Page 30
364
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
rator chip through pins on the socket which have been bent
out at right angles from the socket.
Once the socket pins have been bent, place the socket
over the existing chip (which you should remove from the
board while performing the surgery) and solder the remaining
pins to the corresponding pins on the IC. Note that the chip
enable, pin 11, is also bent out from the original upper case
chip. This is the only pin on an IC which must be bent as part
of the modification.
IC223 is attached to IC201 in the same manner. For this
IC, however, only pins 1,2,7 and 14 are connected to the host
chip. All other pins on the socket must be bent so they do not
touch the host chip below.
The wiring of the two integrated circuits is completed by
connecting the six address lines to IC202 and IC203, and the
two chip enable inputs to IC223 as shown in the schematic
Keyboard Interface
A variety of keyboards which provide lower case alpha¬
betic characters is available at reasonable cost. Look for one
which has a parallel output port and provisions for locking
the alphabetic characters in upper case during the times when
you don’t want lower case. I chose the new Cherry “PRO”
which offers much flexibility in addition to meeting the mini¬
mum requirements.
The Cherry “PRO” has five user-defined keys which you
can wire to provide any output character you desire. I am
using four of them to provide Control-I (TAB), Control-S
(Stop), Control-Q (Go), and Control-C. By adding an
SN74123N dual monostable multivabrator IC the keyboard
has a “Typamatic” mode which repeats all keys if they are
held down for more than a half second.
A schematic for the wiring between the keyboard and the
terminal is shown in figure 3. The data transfer handshaking
requires that the parallel data from the keyboard be present
from the keyboard strobe until the terminal has sent back a
signal saying that the data has been accepted. This handshak¬
ing takes two additional IC’s on the output of the keyboard to
latch the data.
Software
Heath software will support lower case characters. The Text
Editor (Ted-8) and Extended BASIC are the two programs
which can make the most use of the new capabilities of your
terminal. Ted-8 is easily adapted to accept both upper and
lower case characters by typing “L” while in the command
mode, and then answering “Y” to the computer’s question:
LOWER CASE CHARACTERS (Y/N)?
Extended BASIC must be configured to accept lower case
characters. Start with the distribution tape and add any re¬
quired patches. Then follow the instructions in Appendix A
of the BASIC section of your software manual. Type the
prompt L, to which the computer will respond: LOWER
CASE (Y/N)? A “Y” response will configure the software
to accept both upper and lower case characters as String Data.
MONITORS FOR THE 6800
Dear Dr. Dobb’s, Received: 78 June 14
The Motorola 6800 microprocessor is gaining in popularity
against fantastic odds. It has been estimated that some 26
million lines of code have been written for the Intel 8080 so
that all the 6800 owners are busy writing to catch up.
Southwest Technical Products Corp. has helped the 6800’s
popularity with selling systems at prices lower than most
competitors. When they introduced their first systems, the
operating system (monitor) provided was MIKBUG. This mon¬
itor has several problems and for the serious user its replace¬
ment is mandatory. The latest SWTPC systems now have
SWATBUG, a monitor system developed at SWTPC. This
system is also in a MC6830 ROM. For those users who own a
PERCOM, SWTPC, or similar cassette interface, this system
does not activate the RC line and the cassette interface must
be operated manually. M6800 owners do not despair, help is
on the way. First, Shifting Sands Microcomputer Products
Corporation, Box 441, Fairborn, Ohio 45324, manufactures
the RC-68A which is a PC board with sockets to allow user to
plug in 2708 EPROM in place of the 6830. This allows one to
use 2708 monitors such as the SMARTBUG monitor sold by
Smokesignal Broadcasting Co. or to customize one’s own
system when access to programming facilities for 2708’s are
available.
The purchase of the PC board, SMARTBUG, and an MP-S
board which is a must for I/O will certainly upgrade any old
system. This is about the only way to allow use of the Percom
CIS-30+ at 1200 baud, which is the rate used for local storage
by this user, and this done without any errors for over a period
of 10 months of extensive software development.
The owners of 6800 should look forward to a PASCAL and
FORTRAN within the next year so that an update is probably
in order to keep abreast of future advances. I also recommend
for the user the Shifting Sands Dissassembler and Display soft¬
ware. For display make the following patches if one has a ter¬
minal such as the Lear Seigler ADM3A which allows 80 char/
line.
ADDRESS
PATCH
S5E4E
$01
S5E4F
$01
S5E50
$01
S5E51
$01
S5E52
$01
S5E53
$01
$5E55
$01
S5E83
$01
$5E84
$01
I hope that this information will be of benefit to your
readers if you see fit to publish same.
Sincerely, Dept, of Computer Sciences
Chuck Adams North Texas State University
Denton, Texas
366
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
A Programmable
IC Tester for KIM
BY JOEL SWANK
4655 SW 142nd St. #186
Beaverton, OR 97005
With a few dollars in parts and a small program, KIM can
be used to test most SSI integrated circuits and some MSI
devices. The best thing about this tester is that it is
automatically programmable. You don’t sit over the data
book trying to figure out what a device is supposed to do.
You just plug in a known good device of the type under test,
press the program key, and the tester is programmed to test
that device.
This idea was published in the June ’78 Byte by Mark
Thorson, but his implementation is a black box with hard¬
wired logic and memory. I have moved all logic into software
leaving some inverter/buffers, some wire jumpers, and the test
socket as hardware.
The program communicates with the IC through a PIA
(Peripheral Interface Adapter). The 8 bits of PIA port A are
used to receive signals from the IC and the 8 bits of PIA
port B are used to send signals to the IC. While being
programmed the tester sends each of the 256 possible
combinations of the 8 bits on port B to the IC and the
response to each is recorded in memory. During testing, each
combination is sent again in the same order, and the response
is compared with that in memory. A result of not equal means
a bad IC.
Since different IC’s use different pins for input and output,
it is also necessary to connect the PIA input and output lines
to the proper pins of the test socket. This is most easily
accomplished by jumper wires and some easily changeable
type of connector. Unneeded inputs or outputs can be left
unconnected. The power and ground must also be jumped to
the proper pins.
The B port of the PIA is also used in automatic pulse mode
to send a 1 microsecond pulse on its CB2 control line. This
pulse occurs each time data is written to the B port. The
CB2 line is in verte d to become the CLK and inverted again to
become the CLK. These 2 signals are provided for devices
that need a clock signal to strobe in data.
To use the tester, start execution at location 200. The KIM
display will light with 0’s. To program the tester, insert a good
IC of the type to be tested in the test socket. Be sure that the
jumpers are properly set. Press the PC key and the tester will
program itself. This builds the pattern of responses in memory
page 3. To test, plug the device to be tested into the socket
and press the DA key. If the display lites with all 0’s the device
is good. If an error is encountered the display will contain
information about the error. The left 2 digits contain the
byte sent to the tester. The middle 2 digits contain the byte
received from the tester. The rightmost 2 digits contain the
byte from the pattern. The AD key returns control to KIM.
This tester is able to test most 14 and 16 pin TTL circuits.
If 74LS TTL is used for the inverters, CMOS can also be
tested. If care is taken with the jumper programming, some
MSI devices can be tested, and by expanding the software
more complicated devices could be checked.
The program of the tester is the 256 byte pattern in
memory. This pattern completely and unambiguously defines
the logic of the device being tested. Patterns for each device
could be stored in a file for later use. Of course the jumpers
would have to be programmed exactly the same to use the
pattern again later. Are there other uses for these patterns?
Could a program be used to generate the logic from these
patterns? Maybe these or something similar could be used
by the manufacturer to describe a device. The data could be
used to program everyone’s programmable tester.
JUMPER CONNECTIONS
FOR A 7400
Number 28
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, Ca 94025
Page 33
367
1000 : programmable ic tester
<o3 £0 Pi A
p
A
Op
P
A
7
e>
07
"DATA Pfcom DEsJICt
CL-K
CLK II xz.
14 -
Xfc 17
T>P\tA To tC-Jict
Juo^pEP A RSA
l Z 3 + 5 fe 1
R '« u iZ 13 \4 15" l(o
O
X
UJ
3
1-
3
2
V-
»-
CD
X
3
<
►H
<
z
\
A-
a
>
3
X
X
M
l-i
3
z
<
X
CJ
M
3
3
X
2c
a
t-
M
X
X
<
CJ
O'-
<
h~
3
X
10
NO
CO
3
3
z
>-
X
X
X
u
2c
M
M
M
M
>-
X
X
H- X
X
X
f—
M
-J
O
>
>-
X
M
X
C-
3 P- O C'-
CD
o
>
Q
<
X
<
<
X
X
>
X >- X >-
z
X
X
Z
CO
M
X
3
X
»
o
X
*- X X X
X
CD
h-
a
UJ
z
CO
*-
►-
h-
«.
X
X
M
X X
X X
<
CD
a
UJ
M
X
X
X
CD
h-
>
CO
3
X
3 3
3
X
a
M
<
m
CO
Z
u
u
3
fH
X
<
X
<
o <
X CJ X CJ
o
X
X
□
D
CE
JD
»-»
X
X
U
CJ
CJ
CO
>-
J>
z a
>- X >- <
z
>-
z
u
CO
CD
<
UJ
X
X
1-
u
X
X
h-
CO
►H
o
z
CD
z
CJ
CJ
»
■ UJ
UJ
3
<
X
3
<
<
1-
X
' h-
CD
Si
«-
oo
O'
<
CD
Jt
Si
ca
00
00
on
X X
<
ca
<
X
X
<
<
m
h-
h-
X
a
X
JD
X
CO
X
t- CD
X
H—
z
<
gj
CD
QJ
x
U-
U_
5
SI
S3
si
Si
Si
S3
X
^ vU
S3
-J
J X x
X
3
3
Z
Z
z
z
t-
X
3
X
3
X
X
X
i o
X
S3
S3
SI
ca
S3
SI
a
<1.
<
<
<
<
<
a
X CJ
X
oo
X
K-
X
M
M
U t-
CJ
A-
S3 X
X
M
CJ
X
X
3
X
UN
3 «-
XiJXia
3
f-
z
f—
Si
S3
SI
S3
S3
S3
CJ
O
o
CJ
a
O
a
t—
*- e-
S3
on
CJ
(J S)
Q
Q
on
cj cm u
S3 *
♦
*
CO
CD
♦
<
♦
r-
K- «— X
<
3
M
<
O
M
1—
X
_J
_J
_i
_J
_J
-I
<
_J
_l
_i
_l
_j
z
-I _J
-J
X
o
<
<
< X
X
X
X
<
<
<
<
<
<
<
<
X
X
X
C3 < X
X X
UJ
u
O
u
a
o
CJ
i—i
o o a
u
u
CJ
o
cj a
a
CJ
-J
CJ
h—
A-
O h-
z
h-
Q h-
CJ X
a h-
b-
t—
CO
CO
s
X h-
26
a 2 e
X 2 X 2*
z
2
CD
NJ
•
•
•
•
•
•
X
•
•
•
•
•
•
It
• •
•
•
u
X
CD
CO
_J CO
M
CO
3
CD
3
CD
3
CO
CO
CO
3
3
u
X
CO
CJ
QJ O
CD CJ CC CJ
X
3
X
_)
X
<
X
<
<
<
CD
CD
m
CJ 3-
*:
h-
X
h~
t—
CO
X
I—
h~
<
X
_J
<L
X
_j
z x
p-
hH
<
<
UJ
z
z
Z
h-
n
1-
J—
M
i—
CJ H-
X
z
3
3
.. .
" •• «
•• CL
CL
*
M
0.
X •
.. .. .
• a
Q
CJ
Q
CJ
CJ •
’• •• •
• CO CO
a •
■
• n
CJ
.. <
>• —
••
EJSSianSSSISSEilBEdS&lCilSSSUSI
T-oorA^-iPivOr'aDOca«-ojm^irivOt^cDO'si*-i
G)6JscasiaisaBi-«-»-T-T-»-«-»-T-^(\ J c\)i
issieasoacacasis
<
<
<
<
<
<
X
X
U
CD
CJ
a
a
C
CD
*"
*"
T -
3
T-
ON X
oo
S3
U
U ON S3
CD
<
O'
X
<
CM
'O
CM
UN
ca
X
13 - 0^ Si «Ef X
ON
S3
Si X
s
S3
ON S3
CM S3 S3
X
X
X
*"
'O
X
X
3
X
SI «“ X ^
a
O
CD
CD CM
X 3
X
O'
0 O' 0 O'
UN
UN
UN
S3
S3
UN
S3 UN O'
S3
O' S3 0 s S3 O' si CJ
CJ
<
3
3 <
3
X
3
<
3
< 3 <
3
3 3
CM
CM
CJ
X
3
u
3
O X
U X O O ^
S3
e-
ON
>0 O' X
X
X
00
O' O' CJ
X
ca
CM
0^
<
(J
X
ca
(M^vC3<UUJS
S3
S3
IS
si ca
S3
S3
SI
*“
«-
T“ e «
T~
00
CM
CM
CM
CM
CM
CM
ON
ONONONONONONON^J
00
00
00
CM CM
CM
CM
CM
CM
CM
CM CM CM
00
CM
CM
CM
CM
CM
CM CM
CM
CM
(M CM
CM CM CM CM CM
S3
ea
S3
S S3
S
ea
s
S
S3
si ca S3
ca
IS
S
IS
S3
S3
S3
s
S3
S3 S3
si S3 ca s ca
S3
ca
S3
S3
ca ss
ca
S3
S3
SI
S3
si ca is
ca
S3
S3
IS S3
S3
Si
S3
ca
S
Si
IS Si
S3 S3 S3 ca S3
S3
ca
S3
S3
00
ON
UN \Q
(v co
O'
CM ON
UN \Q
O' 3
O'
ca
*-
CM
ON
UN sO
[S3 O' S* -
CM
ON
ON
ON
ON ON ON
ON
ON
ON >3- C <3-
*2 <3 *3
UN
UN UN UN
UN
UN UN
UN UN UN sO 'O UJ
v0
'O
Page 34
368
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
uajcoco<Ocaeuea<3'casis^T*a'si3
uciiciis&ieiic>isssssss&is
(JCOCOCUCCal&lS^SSSCSSS
EJKS&llSSSSSSEdSSISISS
ucococu^ciiejsi^EitjK^ciias
6JS6jK)Seil&lSCilStJSKlSKlS
OXXXUN* - * - * - UN» _ * _ « — iD«~ «■"*-
QcjssisciissssQCJiaejss
UiOCDCD^CJCJS^cjejcjcsieaia
nUMSSSSSBSSQSSKS
UCOCOCO^sisisim-kikisiM'Kisisi
CdSSSSSSS&lSSUSS&lS
UCDCcco^eiaejcj^siHs^isss
SBSSSSSSSSMSS&1SSS
3xxxun*-«--*-un«-«-*“un*-*- , »-
SUUBUSSMSSSISSIS1SS1
ucucua)«j&is&i^6itjtj^6jej(a
SBSBCJHSCijeJMCJBejCJSS
UOaCD^CJCiSCGmU^QQQ
SSSSSSSS&1SUSSUSS
ucDCDQj^cjejcj^isiscj^cjej&j
SSUCISSSCdSSSSSSSS
3XXXUN«-«“*-un*-«-«-un«-*-*-
3sisasi6a6i3tsca3ea33333
LJ
<
C_i
3
<
z
o
<
3
C3
Ci
El
X
X
U
3<<<'DC\J(\JCNJvOC\jr\JCNJvD(NjCNJCNJ
Caeasi5lEl333515iea3Basi5l3
3<<<'Dcnjcnjcnj>ccnjcnjcnJ'0cnjcnjcni
u. E)SSSSSSISSSSS 51 SISIS
l 3<<<U3C\jcnjcnj\OcnjcnjcnJ'Ocnjcnjcnj
r'N SMsstsnassuiBiasssisis
» ll. [iHLiih^nnhnnnM^nn
a easisisisisssisissisiEiscas
z
CC
UJ
<
X
a
o
A
sussoissBisssss&isca
N'-C\jn^ir''OMDO'<CDUQUti. cnj
sssssssssseasssss a
A
LIGHT PEN FOR COMMODORE PET
News Release Received: 78 July 17
A self-contained light pen which plugs directly into the
Commodore PET 2001 user port has been announced by the
3G Company. This light pen makes it possible to bypass the
PET’s keyboard and interact directly with the information
displayed on the CRT screen.
The light pen adds versatility to most graphics programs
and is valuable as a teaching aid for young children. It also
adds unique capabilities for application programs aimed at
the non-computer oriented person. The light pen is complete
and ready to plug into the PET. A sample program and pro¬
gramming instructions comes with the pen. The entire package
sells for $24.95 and is available from 3G Company at Rt. 3
Box 28 A, Gaston, Oregon 97119; (503) 985-7176.
_J
y-
LI
3 X
1
u
LJ
<
U
3 3
M
CD
►H
X
3 )-
u.
LJ
>
3
X
3 3
>
O
LI
3>
3
Q
3
3 X
3
z
M
LJ
3
z
M
K
3
3
y-
3
X
LJ
Z
X
3
:o
>
1-
<
Z
LJ
3
X
z
LI
CJ
z
M
3
► i—
X
l-
LJ
3
X
*
y-
3
<
X
1-
3
3
<
<
3
1-
X
1-
LJ
a
y-
X
3
z
U
X
< Q
y—
y-
<
2
z
<
i-
2
3
3
X
<
3
X
•
X
►—I
z
X
•
CJ
y-i
X
X
3
Z 3
3
X
h-
z
3
y—
y-* >
o
LJ
LJ
3
a
o
X
3
<
<
«L
3
3
<
M
z
>
NO
Z
3
z
X
O
Z
1—
h-
h-
3 M
Z
1—
Z
LI
<
UN
CD
►“
►—
3
cj
CJ
UN
o
<
<
<
I- X
3
<
►—<
CO
CO
CNJ
Q
CO
<
UD
u
z
CNJ
o
3
3
3
>- y-
X
3
u
X
X 3
>-
H-
3
>-
>-
X
•
Z
•
m
o
a
3
Z 3
X
-J
»—
3
3
X
3
3
3 Z
►—
*-
CO
►-
CL
1
X
*—
<3
X
h-
h-
1-
X X
X <
3
<
<
<
_J
<
3
X
LI
3
3
<
X
3
X
Z
z
<
Z
3
<
<
pn cl
ca Q_
3
CL
3
3
Z
X
Sl
3
X
X
3
3
X
X
X
l-H
3
y-
1—
*
ca
*
CL
X
CJ
M
X
Sl
X
3
1-
CJ
*
*
__
♦
<
3
O
►—
Ji
< <
>
>-
<
X
<
>-
LJ
a
3
>-
< X
X
3
>-
3
03
>-
<
<
<
X
3
<
<
X
Z
O f-
3 H-
>-
C/D
h-
z
Z
LJ
(J
Q >
3
2
Z
z
Z
3
y-
h-
o ►—
2
3
y-
3
t-
3
_J CO
-I to
H-
3
CO M
CD
X
X
3
1—
3
CJ
X
w
X
X
X
X
3
Si
“D
X
X
3
X
•
CD
CL
X
o
X
W
a
3
CO
3
X
3
3
X
_J
3
3
X
3
Z
.. a.
CL
"
••
**
*•
t-
f-
•*
3
**
** *•
•• X
**
3
CNJ
CNJ
CNJ
<
<
SI
Sl
Sl
3
3
pn *r-
si
St
SI
ca
X
ud
Sl
ca
Sl
UN
UN
X
X
<
Sl
X
CNJ
Sl
ca 03
ca
3
X
OJ
L
u
Sl
X
X
ca
L
3
L
L
X
L
CNJ
SI
X UN
Sl
^T CD
ca
r-
CD
ca
ca
Sl X
s:
«-
Sl
X
Sl
Sl
^T
UN
T-
UN 3
3
3
ca
< CO
<
CD
O'
CNJ
O' CJ
□
L
<c
O' CNJ
o
CJ
u
3
L
X X
Cl X
^T
CD
<
>D
pn un x O'
CD
U
L
CNJ
m3
X
O'
CJ
3
ca
«-
PN
un o x
3
Sl
PN
nC
M ^
<3-
UN
UN
UN
UN
UN
UN
UN
UN
m3
vC
>D
X UD \Q 'O X
X
X
X
cnj cnj
OJ
CNJ
CNJ
CNJ
CNJ CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CNJ
CM
ca ca
ca
Sl
SI
SI
SI
ca
ca
Sl
Sl
Sl
Sl
Sl
ca
51
Sl
ca
51
s
ca
Sl
ca
ca
j H Q
St
Sl
SI
Sl
Sl
Sl
Sl
Sl Sl
Sl
Si
SI
SI
Sl
Sl
Sl
Sl
Sl
Sl
Sl Sl
Sl
Sl
ta
ca El
si ca
si ca
ca
IS
3
3
n vo x cd
O' Si
«—
CNJ
PN
ST
UN %D
x
CD
O'
El
CNJ
pn ^
UN
UD
(V X
O' si
*-
CNJ
CN ^
X CD
X
3
«—
G vC '■O
vO
nO
X X
x x x
O' X
x
x x cd co
X
X
X
X
X
X X
X
X
X O'
X X
X X
X
3
3
3
- T~
*■
«“ «-
*-
*-
«“
«“ «-
*- «-
*“
CNJ
CNJ
CNJ
uj^u» - f r iscMEic\jc^m<0'eiac\j*-tsmcD<r r >s»u.u.'DCD
3CNJ«-eacasiS!ea3X'0'CL5ia:Ea3<tfLL^TX«-<0UNUN
a3CNJCNJ<<<<<<CNJC\iLeacNJsiea5iCNJ'S5icNjCNJLUC\JCNJ
<SSQOQQQQBSr5iaiSHSSSBiaSfrSIS
Cj q. <X<G3<CDteOZ
iaiJJII<<DirhIHj]hh3hhOJZIJ3D
>JJhhHH|-h2llu < '2LJ<<JZZIIDUhliJJ
J]<UUOOQOCUJUJDHH^a.Q.a.Q.Q.Q.Q.J3tflhK
Number 28
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, Ca 94025
Page 35
369
NEW COMPUTER LAW
Dear Dr. Dobbs: Received: 78 July 17
Computer users should know about SB1766, the “Fed¬
eral Computer Systems Protection Act of 1977”, now working
its way through Congress. The vast, open-ended scope of its
wording makes any use of almost any computer “without au¬
thorization” punishable by 15 years imprisonment or fifty
thousand dollars fine.
While directed mainly against financial crime, the wording
clearly covers students who play games with computer time
intended for class assignment use, or employees who use com¬
pany computer time for unapproved research on personal pro¬
jects. Another problem concerns university and other com¬
puter centers where typically a few files are explicitly confi¬
dential, some are explicitly public, but most development
work is accessible but not explicity public, essentially a kind
of proto-publication of “anyone can look at this but I don’t
assume responsiblity for correctness.” It is common practice
to browse this work for the sole purpose of keeping up with
the field and improving programming technique. Under the
new law, any use of this vast and irreplacable community
library could be interpreted as a felony.
The law could deter public use of open-access community
bulletin boards (which now exist in several cities), open com¬
puter conferences, and other public data bases. These free
computer services are more than just experiments or toys,
as someone setting up one can be repaid many times over by
up-to-the-moment, specialized professional information com¬
ing in. We can expect hundreds of scholars or groups to start
open-access computer conferences or data centers for special¬
ized interest areas (not necessarily computer oriented) as term¬
inals become more widespread. Although using these services
would be entirely legal under the proposed law, it may be
hard to communicate which ones are open, because typic¬
ally no advance arrangements are made. Commonly you hear
through the grapevine “call this number and hit carriage
return”, and often there is no way to even find out who is
running it, short of attempting to log in. If the computer
turned out to be restricted to members of a certain organiza¬
tion, the law would be broken, and usually a record of the call
would exist.
Essentially this proposed law covers every possibility and
leaves the actual definition of what is or is not legal to prose¬
cutors and courts. This is poor legal draftsmanship, as over-
zealous prosecution does exist, especially in hot new areas
of law enforcement, and defendants are stripped of legal
protection.
This proposed law covers so many legitimate activities
that it threatens the natural growth of decentralized computer
use. It appears to have been drafted without proper input
from industry. Congress must hear from industrial and profes¬
sional groups, or it will pass a law with effects which could
not possibly have been intended.
Sincerely, 1090 Miller Ave.
John S. James Berkeley, CA 94708
95th CONGRESS
1st Session
S. 1766
IN THE SENATE OF THE UNITED STATES
June 27 (legislative day, May 18), 1977
Mr. Ribicoff (for himself, Mr. Domenici, Mr. Griffin, Mr. Heinz, Mr.
Jackson, Mr. Kennedy, Mr. Metcalf, Mr. Percy, and Mr. Thurmond)
introduced the following bill; which was read twice and referred to
the Committee on the Judiciary
A BILL
To amend title 18, United States Code, to make a crime the
use, for fraudulent or other illegal purposes, of any
computer owned or operated by the United States, certain
financial institutions, and entities affecting interstate
commerce.
Be it enacted by the Senate and House of Represen¬
tatives of the United States of America in Congress assem¬
bled,
That this act may be cited as the “Federal Computer Sys¬
tems Protection Act of 1977”.
SEC 2. The congress finds that —
(1) computer related crime is a growing problem in the
Government and in the private sector;
(2) such crime occurs at great cost to the public since
losses for each incident of computer crime tend to be far
greater than the losses associated with each incident of
other white collar crime;
(3) the opportunities for computer related crimes in
Federal programs, in financial institutions, and in other
entities which operate in interstate commerce through the
introduction of fraudulent records into a computer system,
unauthorized use of computer facilities, alteration or
destruction of computerized information files, and stealing
of financial instruments, data, or other assets, are great;
(4) computer related crime directed at institutions
operating in interstate commerce has a direct effect on
interstate commerce; and
(5) the prosecution of persons engaged in computer
related crime is difficult under current Federal criminal
statutes.
SEC. 3 (a) Chapter 47 of title 18, United States Code, is
amended by adding at the end thereof the following new
section:
“ 1028. Computer fraud
“(a) Whoever directly or indirectly accesses or causes to
be accessed any computer, computer system, computer net¬
work, or any part thereof which, in whole or in part, operates
in interstate commerce or is owned by, under contract to, or
operated for, on behalf of, or in conjunction with, any finan¬
cial institution, the United States Government, or any branch,
department, or agency thereof, or any entity operating in or
affecting interstate commerce, for the purpose of (1) devising
or executing any scheme or artifice to defraud, or (2)
370
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
obtaining money, property, or services by means of false or
fraudulent pretenses, representations, or promises, shall be
fined not more than $50,000, or imprisoned not more than
fifteen years, or both.
“(b) Whoever, intentionally and without authorization,
directly or indirectly accesses, alters, damages, or destroys
any computer, computer system, or computer network
described in subsection (a), or any computer software,
program, or data contained in such computer, computer
system, or computer network, shall be fined not more than
$50,000, or imprisoned not more than fifteen years, or both.
“(c) For purposes of this section, the term —
“(1) ‘access’ means to approach, instruct, communicate
with, store data in, retrieve data from, or otherwise make
use of any resources of, a computer, computer system, or
computer network;
“(2) ‘computer’ means an electronic device which
performs logical, arithmetic, and memory functions by the
manipulations of electronic or magnetic impulses, and
includes all input, output, processing, storage, software,
or communication facilities which are connected or related
to such a device in a system or network;
“(3) ‘computer system’ means a set of related, con¬
nected or unconnected, computer equipment, devices, and
software;
“(4) ‘computer network’ means the interconnection of
communication lines with a computer through remote
terminals, or a complex consisting of two or more inter¬
connected computers;
“(5) ‘property’ includes, but is not limited to, financial
instruments, information, including electronically produced
data, and computer software and programs in either
machine or human readable form, and any other tangible
or intangible item of value;
COMPAS EDITOR AND ASSEMBLER
FOR 6500 FAMILY
News Release Received: 78 June 23
Computer Applications Corporation announces the
immediate availability of two software packages for the
6500 microprocessor family made by Rockwell, Synertek
and MOS/Technology. These are a text editor (E/65) and two-
pass assembler (A/65) designed to run on any 6500 based
system. Both programs are similar to software written by
COMPAS staff and offered in the Rockwell System 65. Each
program is designed with transfer vectors to link the program
to I/O routines in the user’s system.
E/65 is primarily designed to edit assembler source code.
Line oriented commands specify input/output of text and find
specific lines to be edited. String oriented commands allow
the user to search for and optionally change a text string.
Character oriented commands allow cursor positioning and
character deletion. Text may be loaded from or dumped to
a bulk device other than the system terminal. E/65 also
features a second entry point to edit text which is already
in memory.
A/65 is a two-pass assembler which conforms to the
specifications detailed in the Rockwell and MOS/Technology
cross assembler manuals. A full range of run-time options
are provided to control listing formats, printing of generated
code for ASCII strings and generation of object code. Object
“(6) ‘services’ includes, but is not limited to, computer
time, data processing, and storage functions;
“(7) ‘financial instrument’ means any check, draft,
money order, certificate of deposit, letter of credit, bill
of exchange, credit card, or marketable security;
“(8) ‘computer program’ means a series of instructions
or statements, in a form acceptable to a computer, which
permits the functioning of a computer system in a manner
designed to provide appropriate products from such com¬
puter system;
“(9) ‘computer software’ means a set of computer
programs, procedures, and associated documentation con¬
cerned with the operation of a computer system;
“(10) ‘financial institution’ means —
“(A) a bank with deposits insured by the Federal
Deposit Insurance Corporation;
“(B) a member of the Federal Reserve including any
Federal Reserve bank;
“(C) an institution with accounts insured by the
Federal Savings and Loan Insurance Corporation;
“(D) a credit union with accounts insured by the
National Credit Union Administration;
“(E) a member of the Federal home loan bank
systems and any home loan bank;
“(F) a member or business insured by the Securities
Investor Protection Corporation; and
“(G) a broker-dealer registered with the Securities
and Exchange Commission pursuant to section 15 of the
Securities and Exchange Act of 1934.”.
(c) The table of sections of chapter 47 of title 18,
United States Code, is amended by adding at the end thereof
the following:
"1028. Computer fraud".
code may be stored directly in memory or output to a file
which may be the same as or different from the listing device.
Thus an assembly may be made for listing only, object code
only or both.
E/65 and A/65 are priced at $100 each (Prepaid) and are
supplied in object form on paper tape or KIM compatible
audio tape. Listings of the source code are available for
$25 each. Programs are assembled to start at memory location
200 (hex) but may be ordered to start at any location if a
listing is ordered. Full documentation on the installation and
use of each package is provided. Contact COMPAS, 413
Kellogg, Ames IA 50010; (515) 232-8181.
RUMBLINGS ABOUT DIGITAL GROUP
Dated: 78 July 25
Persistent rumors have been circulating about Digital
Group’s financial troubles including the suggestion they
were about to file Chapter 11. A call to Digital Group gleaned
the following: Ms. Edgar, secretary to DG president Dick
Bemis was rather candid about the fact that the company was
having financial trouble but that they had had a meeting
with their creditors who were working with them to solve
the problem. She assured me that Digital Group was not
filing for Chapter 11. — TRW
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 37
371
Dumping Northstar Disk Files
BY TITUS PURDIN . ■
5901 JFK # 101
North Little Rock, AR 72116
Dear Sirs, Received: 78 Jun 20
Enclosed is a small utility program which I have found very
helpful in designing and debugging disk files. I found that,
with my limited operating system, I could not look at the con¬
tents of such files in absolute form. I was wasting a lot of time
writing utility programs in BASIC to read disk files in logical
form as an aid in tracking down bugs. Problems such as end-of-
record marks spilling over into subsequent records simply
defied detection.
This program was designed to run in a Northstar environ¬
ment and uses the disk drivers in Northstar DOS, but could be
adapted to run with other operating systems. The program
reads named disk files of any file type and prints the contents,
16 bytes per line, first in hex and then in ASCII. Each line is
numbered to show the relative location of each byte in the file
in hex. Non-printing ASCII characters are replaced by periods
(.) in the print out. The print out can be interrupted with a
line feed (OAH) and restarted with a carriage return (ODH).
The print out can be aborted with a control-C. In the event of
an abort, certain input errors, or normal program termination
control is passed to Northstar DOS.
h
X H ~ XXX
WQU.22 H o O O
% % X X •> * O — Ca] CM Cal CO [a]
oxocltocdococjcoocoo
J J J > J
EJ00_4CJE00*}0“50"5
QQ-*Cyn'73SlSSS)S(SSQSS(SS(S' H
r-oocr>cncoooo\<s — cv)n<Tif>NOC'-ooO'® — evict)
i/ii/iinihi/ii/iin<ovOvOvC'CvcvC'C>ovo>r't' f '
CD
<t
O
CD
CD O
O
O
<t
<1
<E
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
m cd
o
CM
in cd
<t
<r
IS
CM IS
CO
«S
u.
(S
(S
O
u.
Ca]
U.
CO
<7 ro <r
CO <1
CO
<r
Q
CO
w
Q
Q
QpQ
Ca]
Ca] <t
Cl]
<t
O
o
s
CM O
O CM
O
o
(a. O
la. O
Ca.
o
in
CO
CD
Q
S
CO
O
O O Q
&
CM
m p* <r
o
o
O
O
P»
t-
C*»
r-
CO
CO
CO 00
00
CO
<r
<r
<t
<r
<1
<t
<t
<t «t
<r
c
<x
<t <1
<x
<r
CM
CM
CM
CM
CM
CM
CM
CM CM
CM
CM
CM
CM CM
CM
CM
— 0. CM Ca]
if- X H _) <%
Q 2 'a. Ca] ^ Q 7
E — X -• Ca. — X
* * x x £ * * x <t
oxcLo 2 oxo.*co
-i -j j
:> •< t: u!
e -J o o
3
_J n.
_ j _ 2 * x i
:> x: <t v: :> — :> 2 o i
E _1 O .J E x •— Q 1
X
X w •£ ■><
O J2W
X *■* -
[a. Ca. CO
- in x
f— —•
a 2 h
Z -J T 3 T 2 O
o q 2 i*. o
O I S H ih o <1 I
T X J
H 8 H h. H h
X
u
Q
Ca]
2
to
H
J
<t D CM D in D [a.
H
J
X
X
«t <t 3
u.
«* O % O t O 2
o
i
0.
UJ
% * O
2
CD a CD U CD U
f—
IE CD U X CJ
J J J
* h\'hQ,
.NQ.25'EMQu20<I5253!f:
)"DO"35!U“DjQ-.j;OS:OSO"3
<t •
I«IW2
O u 2 <t
X <t x
W <t 2 O
u
o O 1x1 co
<r h j
J 2 H t«.
a. —. u. •-«
_ J _ J J
55 jyfllN Jhh j
oo3zoz<t:>y3
EEU-mQTOE-JCJ
i/ississss ^ s s s
QQSSQ-OlO^irt'Oc'COO'S
SKJ'StSQ&'SfStSlSlSQ'SiS®
^ ^ O
^ l •« M •« •. •* •. •. •< M ^ O
a0^iS8SS8S l SSSS(9S8'*Oir)S8QQISS8SS S l S®S)®«S®Qin<S-*CMf'5'CiniSSJ®®(StS><S®®®
fl00'5-wn^ifi\0t'M(j»!8-<Mr)<rifi'0*0'£)v0N!Dos-wn<ri/)'0t^r0ais-cun^ininic«0»0'0'0'0Nc00'®-w«<rir)'0
q®-« — — — — — — CMCMCMCMCMCMCMCMCMCMCMCMCMcor)cocococo< r >cococo<7'3’<7<T<T<7<7-3 , ^ , <T < 3 ,< J , ^ ,J T^ < Jininininininin
888288SS88Q88888888888888888888888888888888888888888888888
o cc cc
CM CM CM
u. in z. to
cm u.
w - .d a
Q CM C O
® CM iP CO
® <3 <S Q
<t <I <r <t
CM CM CL CM
O CC O
CM CM CM
. i. ■c cc ® <r
e p- w r«. <s>
JC — Q — td
S CM O CM S
a: a t* n >o
— —
<t <r <t <t <x
CM CM CM CM CM
<c o
CM CM
<S S) 8 O
CM — U. ®
vo co a cm — ti]
n CM S U CM s
CO <t CD o U. CM
oc « <c ^ <c <c
CM CM CM CM CM CM
o u -di <r «tu o o o <r
CM CM CM CM CM CM CM CM CM CM
<t - Q 01 li. 8 O <7 — — (S — U- — <7
n in ® lO If) if) ® CM 1/1 <7 CM C7 IP <7 CM
UI*)kOl«.Or)0]onCM87U8OSUU
<Jb ( tOl».-^« 0 P<tQU|i. 8 nill 00 <tQ
ciCMCMCMWnnnnnnnn<r<rq , <7<7<7
<t<t<t<t<t<a:<r<t<t<x<t<r<i<E<t<r<r<x<i
CMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCM
o <i cd o cd
CM CM CM CM CM
— m is cm cc
<7 CM U. — CO W
P6QnQCMQW-Q
b^OCMSOOSCMU
Q-*CMin»OP-<tQU.CM
inminininininmino
<t<t<c<t<t<t<r<t<£<r
CMCMCMCMCMCMCMCMCMCM
Page 38
372
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
•- X
3 ^
z
x ® ® c
co o css -
— —■ CVJ C
Q
X
X U * ,
H X tO
X * ■
Q W Q
CD .
H X
3 O X i
0. H H I
2 CO
CD
1
2
: o w
X NJ
U 2
Q 3
X
T H
o
f-
2
X
o
X
U
o
3
o
Z
CD
2 3
to
o
to
X
to
X
u
o
3
X
X
3
Q
to
X
•
Q
to
U
to
2
X
u
H
s
X
2 3
*
Q
h
o
Q
3
X
u
X
X
X
X
o
X
u
Q
2
X
2
o
o
X
u
X
H
X
z
X
CU
H
X
—t
U
CU
U
2
X
X
CU
X
2
®
to
— 3
z
Q
Q
CU
%
Q
—i
CU
%
% *
Q
®
to
X
m x
o
Q
X
CU
H
O
X
H
u
to
X
2
X
_t
H
o
3
3
Q
2
<-•
*-•
3
3
-J
to
. U I
U x
CJ X H
X U
3 a: z
a. <t o
00
X H X
1 X Q 2 U. CO
i -* X ~ 3 CVJ
1 * % x x ®
iUXO-UW
z
X >•
X O U
w - X
X x H
<t 3
to
X - X
H H
X O X
Q X U
3 X
U. CD X
O -
<r
a o h
2 H X
— Q
2 O
2 x z
u o
O to x
X u.
CD 'O
U CO
U. 3 U
0 0 2
X 3
o
3
X CD
X
H U
CJ 2
<X -
- 3
Q X
2 O
<t <t
W
X CO
H X
O
x to
- X
U
X X
H H
> 3 *: o •< rr x 2
. 2 3 £ _J 3 O 3
5 3^2
Z 3 cj o 3
Q X
25
x a
i — oj co <r i
I CVJ CM CM CM <
I CM CM -
X
J
CD
Q
, «* X
l P- s>
i oj co
' — CVJ
® ® ® ® (S ® ®
tr ifi <c t* co o> s
cvj cvj cvi cvj cvj cvj co
StJSStS-
-> c\i n ^ i/i i/i
n n o o o n
vO CO Q CVJ
<o cvj ® cj
OUJU.es
U. X u. ®
x x x m
CVJ CVJ CVJ CVJ
O outset) O CD CQ ®
CVJ CM CM CM CM CM CM CM CM
-* -* x xxcumuxcDmco
8QU. XXCUCU®CJUUCU
U'O-U-.^QCUU — Qpco
nscvic-cviuQscviuou
Ot/)C^<riDlil-<T^O'UU-CVJ
®®®ts®®—-cu
cDmmxmxcDCDCDmmmcD
CMCMCMCMCMCMCMCMCMCMCMCMCM
to
3
•
Q
X
CD
f-
o
X
Q
Q
u
2
t-
U
X
X
X
2
H
X
X
Q
3 Z
t—4
X
X
U X
X
X
X
Q
U
O
—•
X
X
t—
(J
X
H
X
\
O
X
3
to
a
X
to
H
to
3
u
2
(-*
a
3
u
3
3
u
—<
X
M
o
o
X
X
3
X
H
z
o
3
H
z
*
CU
CO
•T
m
sD ®
®
®
CU
CO
X
®
in
in
in \o
co
CO
00
CO CO
®
co
co
co co
CO
CO
CO
CO
CO
CO
CO
X
X
“
“
“
"
-
a
u
u
CU
X
X
u
a
X
X
X
X
CU
X
CU
X
"•
<t co
<t co
CO
m
CO
O'
o
o
®
CU
CU
CU
w
CU
CO
CD CD CO
X
X
X
CU
CU
X
X
X
u
X
w
X
u J
2 \
- X
J
a
2 H
-« 3
X
to
to u
u CD
X
o J
a 3
<r
3
U
X X
H U
H
tO O
Q X
-J X
— <t
5 X
X O
X I
s !-• <i ;
% CJ i
m x o :
-« X 3
3 a o
£ J z
'Cvin^sssssss
a
H
J)
3
u
hH
H
to
U
X
u
U
u
X
to
o
X
to
2
X
o
to
u
O
H
H
u
to
2
2
o
to
to
3
3
H
u
3
>.
«
z
Q
a
2
X
H
_l
2
a
2
3
3
<£
2
<2
O
<2
X
to
H
H
to
o
X
H
Z
■H
X
X
X
o
X
M
X
u
u
X
to
X
H
Q
u
3
X
H
CJ
O
U
3
z
X
X
h
X
o
z
u
v:
X
3
X
U
3
u
X
H
—1
2
X
X
z
H
O
o
H •
•
_■
o
to
to U
X
X
H
X 3
u
u
o
2
—<
5 J
~ Q <t
X X Q 3
3 Q 3 Z
X X
o <
X I
X H t
a <r
►H Q
X
Z :
U O I
X x I
f- U I
2 H 2 • tO
U X
~ X 2 X
X u 3 *
CD tO O o S X Q
: x h
’ U 2
i X »,
X
X X
x5
X02Z30ZQ
XQO<tOS^J
U Q
X CVJ
SOW X
® X <S ®
O X U. — O' <c VO
80^ W8-8
co m oo O' o Q u
co co co co co co co
X X X CO X X CO
« CVJ CM M CV1 CV) W
• wntj/iiOMo^si/isssssss
icococomcocococou'O'S-cvjn^i/i'O
X o
X X
® U ®
■7 0®
u.mcu*cQr^cox
Q®OUCJC*-CU —
® — xinr»<£mu
xxxxxxxx
xmxxxmmm
xxxxxxxx
3
X o
X
2 X
u
X -
3 2
a
X u
H
u to
O 2
3
X 3
X
>. Q X tO
-J
X X
X U
o u
X to
X
U to
3
- o
H *-h
3
2 u
3 X
X
a
— 2
X ~
3 to
2 H
D ~
- Q
u
to
H tO
2 J
X 5
X X
X 3
-J J
!xx
X u t
X J ■
2*!
X o
o X :
H U <
X
» X
u
► 2
— • X
0X00
X o ® ^
- U X o
X o
H (— -
X 2 X
m
X X Q z X 2
J"ThJ3
X «. % X X Z
O O X x o
3 to
X U
2 X
— o
2 H U Z 2
H X
• H 2 X H X 3
Z 3 Z ~ H •
Z X U Q
U 3 3 X U
-J - X H
OJ-i O Z 2
H X X Z O O
3
O Q !
X 2 X
H X
H I
3 I
H
X H 3
H
X
H
H
o
Q
CO
_
z
H
2 X H H
-• a
X
O'
Q 2
Z n
Q
2
X 3
a
H CU 3
X
3
X
3 ® 3 •-«
x -
Q
X ~ w x
X
M
d “•
o
eo
X
Z 2
r- X
O
Q
X % O 2
% ®
H
•« x % •»
X ~
X
X z
to
■>
•i O
a
X
O
®
U X O 3
X X
to
o
H
P
C
H
X a
X
X
o -*
u
X
o
Q
X Q X Q O O
u x
o
Q
o
o
U
>•
u
X
to
z
3
X
to
to
z
X
X
to
to
3
o
•-i
2
3
to
to
X
H
to
X
to
u
X
u
u
3
a
X
z
3
u
to
X
u
o
3
o
3
a
a
X
H X
••
X
X
a
X
u
2
X
X
*—
3
X
a
X
X
u
m
u
a
t—
u
s
X
CO
X
in
tC
r»
X
O'
®
in
CO
CO
CO
CO
CO
co
CO
co
CO
CO
O'
O'
O'
r*
r-
c*>
r-
p-
p~
p*
®
®
®
®
®
®
Q
®
®
®
®
®
®
J J J J JJ
20X0XX23XQi<X23xX3XX3XXXZ
XZ0Z003Z0JJ03ZJ0ZJ0ZJ003
Q
X
-i -< :> x •<
3X0 HZ
r 3 z to -.
x
a
H
K tO
x X rsj H H
2 O 2 3 X
~ Q 3 Z 3
X
3
O
X
C 2
5 - 3
j j <j a
^ x ^
: x o m o x
. X CC NJ M
> z o 2 3 x
: - a 3 z 3
NJ 3
to f-
u z
3 -H
O X
Z X
>wco®®®®®®ss®cs — ■
!®®SSSS8S®S88SS®888'
)®®®®®®® — -
:QO®®®<3 — cvjco
■CO^Ul'O^cOtDSOffl
CD O 03 CD <t
X CVJ X X CVJ
in u u co m m
X ® o U X o
O U - Q Q CO
U 8 CM U u U
X CVJ <T C' <t Q
® O' O O' O' O'
X X X X X X
CM CM CM CM CM CM
o x u o O ® X
CU CVJ CM CM CM CM CM
—•QXX'-"X TO,, ' M
x®« ®
O ffi
CU w
a cd
CU X
o CD CO X
CVJ CVJ CVJ CU
\ ^ aj ^ n
'Or'QP-QUW'OQ
U p> • * *»—»**
QCUU — QU — QU
' l - V4. W Ut. " V, M M IIMV S U Ql W Ul OJ UJ
iXxxxxmmmmmooooooQQQQQ
:xxx<txxxxxxxxxxxxxxxxx
JOJCVJWCVJCVJCVJCVJCVJCVJCVJCVJCVJCVJOJCVJCVJCVJCVJCVJCVJCVJ
m
CD
oo X
CO
00
CJ
<s
<s>
X
u
®
® x
u
X
u
X
u.
Q
a
CO
u —
u
X
CO
CO
a
X
u
VO
co
Q
X
UJ
o
o
® —
p'
X
®
a
®
X
CO
X
®
o
Q
CO
CD
u ®
CO
X
m
'O
p“
CO
m
Q
®
X
CO
X
p-
a
Q
Q U
u
u
u
u
u
u
u
u
u.
u
u.
u.
u.
x
X
X x
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X
X
X
X
X
X
X
X
X
X
X
X
cu
X
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 39
373
<t £
^ X
J <S
CD cn
CD
§
2
X J (
- X r
> £ <
£ O *
S3 <3 l
p» co (
<3 S> r
CM CV) c
. V! 0. <
• U £ I
: a *o .
q u
• <C 2
> U «
• X j
l X U H
!~ m S
) til o 2
: u h
J CO U
: u x
O J H
3 H •—i
: x co
: 2 co
hUil
• X x <J
« H O
O X
. H 2 X
CO o
1 U to H
1 O X
1 O U CO
o u
> -J -J o
• O ffl cd
X
H U J
• 2 X O
> O O X
: CJ £ H
1 2
i to It) o
<t X O
X <*
> H
: h u o
> - X 2
] u
: x x x
) CO CO CO
I CO CM (M
X -1 H 2
x m u j
is x x H
* o _j x
oq m £ <t m 2
— x X <t X
> £ M 2 H £
S U ^ H CO o
O
J
m
CV]
♦
X
Q
Q
<t <C
CM
2 ♦ :
X X .
Q Q t
2 Q £
W <c £
X
X 2
-J —
X
J
ffi
X
•% cj
® S S3
— CM CO
CM CM CM
CMCMCMCMCMCMCMCMCMCMCMCMCMCM
I S S 8 S 8 S (
■ in *o r» oo o s ■
-J
CD
X
o
£
<s s
<7 lO
CM CM
CM CM
<C X
a o
J Q
S3 s>
o p-
CM CM
CM CM
M H
r> to
<s <s
CO o\
CM CM
CM CM
u
X
o
X
o
5
X
CD
X
o cj
J
5 5
CJ £
X H
Q 2 X c
*5s!!
x x o c
8 8 8 8
S) — CM CO
CO CO CO CO
CM CM CM CM
® <s
<y io
co co
CM CM
J J
Zii
JUU
s> s s»
'Oh*®
co co co
CM CM CM
CD CD
Ci] U
X X
: x
• o
i
X
I u
: m
!5
. 2
H
£ 3
* O
CD O X «
: x k> i
: u 2 i
iQTt
5 H <£ H
S3 a S D
«. O •. O
mumu
j j
H JH Jh
£ cj £ CJ X
2 X
o X 2 X
cj s> u <r z q x
•* ■* X CJ * i <1
xmmxcDxto<tmz
Q Q
X X X X > _ J H
XXr>£w22£OOXU]
IOJEOThmTSSJX
8 8 8
O' tS —
n <r <7
CM CM CM
— S3
— CM
CM CM
X
. X
8 8 8
co ^ in
<T
CM CM CM
b.
(£
X
(3 S3
vo p*
>r <y
CM CM
SS88S8888888S888QQQ88888
®os-wnqin»or'coosi-cyn^io»£)^coo'Q-
■q , <yiomir)ioiOioioininir)\0'0^'ONOvOvov£)'0\oc^r~
CMCMCMCMCMCVJCMCMCMCMCMCMCMCMCMCMCMCMCVlCMCVJCVJCMCVJ
CO
m
u
CM
CM
CM
O
<3
CO
U
X
m
CO
5
■q 1
(3
CM
>o
m
co
<r
<t
O
CJ
CO
CM
CJ
CO
S>
X
CM
■q 1
in
00
o
CJ
<c
m
m
m
m
m
m
m
m
m
CD
m
m
m
CM
CM
CM
CM
CM
CM
CM
m
w m
U
W
CM
CM CM
CM
CM
O'
U CJ
<T
*>
CJ
CM
<7
tO <t CJ CM CO
CD O CO CO O
coum
CM CM CM
<t O CO
Q <3
— <T <t Q <£ CM CO
CM CO CO CO CJ CO CJ
o' cj a s> — <y p-
CJ CJ CJ Q Q Q D
m m m m m m m
CM CM CM CM CM CM CM
m CJ CD CO <3
CM CM CM CM CM
id q to m m b
X <3 Q U X CM
DW-QQP)
CJ S3 CM CJ CJ CJ
<t Q X CM lO to
Q Q Q U) U U
m m m m m m
CM CM CM CM CM CM
- m
u
vO Q CO Q CV] o
truwsau
m o x is — <r
u U U X x x
m m m m m m
CM CM CM CM CM CM
CM
Q - <t •
Q ^ Q ^
O Q O Q O'
8 CJ (3 CJ CJ
in <t o X
X X X X X
m m m m m
CM CM CM CM CM
Wo O O U
CM CM CM CM CM
X 8 8 — CO 13 X
■q > u ® — si ts -7
CM — 'OCO<tqn(OWB<t!>
CMCM8ffiU8CMUf“8CMU
tsniOBO'OQW^cMqr*
88888888hhh m
cjcjocjocjcjcjcjocjcj
CMCMCMCMCMCMCMCMCMCMCMCM
H
X
X 2 <t
X I>
X X to
-- O H ® H <t <t
».=>•» ■» CJ ^ CJ ^
3 o£ooo<txm<coxm
J
2 <i
> X X X > <c.
-02220H:
<io£mhhsio:
)5 hhXUm
id
— X
J
to
f— —
2
— u
X 2
X -
J
2
— H
2
X —
u x
H X
o
Sb
U H
O 2
<t D
J o
X o
a
x
<t
O >•
CD -J
>• J
u —
X o
O X
£5
2 H
O
£ J
J
2
H X
X O
X
X
X
<t ..
o
w
x w
X
CJ
u
CM
H
CM
CJ U
o f—
o
2
3
*
D
*
CO
% o
X
m
m x
<x
l-H
£
u <t <t a
o
O X
J
-t o
CJ H
<t
5
to
H
—
X CJ
—
<t to
> x > <r x
<t
3
£ 2
>
X
o
2 O H 2
£ 2
a
£ CJ *0
£
co U
£
— £ co —
£ u a
X
H J
2 (
- X .
X O *
x x :
J „•
o
X
<t x
X
X
H
CJ •
>• C
u
_ u
m u
X
X 2
H
H
3 -
a u
J
w a
to
X
i-
f-
U H
^ to
X
m 2
o •
£ —
i—
CO to
5 X
<£ O
2 X
2 X
a
— a
X
U X
s
CJ o
2 O
X V
M H
2
H
X CM J 2 X
ai^^xai _j v*.
ocjxa.o<tx®o
J JJ J
0£J00X0U1
O
O X
J o
\i 3
<t J
3 -
H
W 2
X D
H
to
D
. X
H X -<
J D <t
X IS 3
J
J —• M
5X2
CJ O "0
O X
I H
H O
CJ
W
2
X J
a x
2 ^
w x
J to
w
X H
w >-
x m
U X
X D
H O
X
5 52
to be -q-
* x •*
£ <t £ O £
D
O
w
X
X
w
El
2
V U
<1 X
o u
2
X 2
CO
W
O X
H H
X
X D
•— i
>-«
2 CO
X H Q> N] H
<c
H
X N3
X
w x
2 ^ £ 2 >
o
tO U
o a
J
£ —
— £ CJ r> £
H X
w X
CO
CO
X
u
x’ a
CJ w
V
X 2
CJ
2 X
m
5
H <t
sj
M H
§
H
H
2
(3
C3
(3
S3
S3
S)
S3
S3
s
S)
s>
S3
s
Q
—
CM
CO
q
s
S3
S3
S3
S3
S3
<s
<S
Q
CM
<s
S3
<S
ts
S3
(3
s
S3
S
_
■q 1
s
O'
to
O'
—
q 1
U>
in
o
CO
O'
S3
—
CM
CO
m
m
in
P-
O'
—>
CM
CO
C
n
m
in
in
m
p“
'O
'O
\o
o
'O
-o
P»
c*»
p-
C'
P>
CO
to
CO
00
CO
co
co
to
to
to
CO
CO
O'
O'
O'
O'
O'
O'
O'
O'
O'
O'
O'
O'
rr»
O'
O'
O'
O'
O'
S3
S3
S3
S3
S3
<S
<S
S3
CJ
~
“
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
O
w
u
a
m
u
CO
m
CJ
m
m
CJ
CO
m
W
CM
CM
CM
CJ
a
<T
X
IS
X
a
S3
CO
n
CJ
rr'
in
<
CC
a
CO
U
<r
'O
CM
■q 1
CO
X
q
X
-ii
X
S3
o
o
O'
<l
X
O'
<t
o
'C
to
CM
W
o
O'
CM
CO
U
CM
a
u
a
a
a
S3
r-
■ty
CM
U]
s
m
a
CO
is
p-
CO
S3
m
U
o
S3
CM
CJ
o
<t
CJ
X
O
o
X
CJ
X
CJ
CM
CO
CO
m
CJ
CO
a
X
CM
CO
<7
m
o
<
CJ
X
CO
in
p-
O'
<t
a
X
S3
CM
in
O
CO
O'
o
X
<y
<t
m
u
m
in
O
o
o
o
*)
o
'O
o
P-
p*
p-
p*
n\
m
m
m
m
m
m
m
m
01
01
01
01
01
01
m
m
m
m
m
m
m
m
m
CD
m
m
m
m
m
m
m
rr
m
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
CM
Page 40
374
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
H H
: x x x x
r o so u.
i a. s >f i - h
IZZnZZWZZmZZsjZZU]
i«<TH<i(i:H<ta:M<i 2 :M« i x
o ••
H Ci]
•• OH
cvj U o
H O Z
x
Q H •
Ci] o <t
o <x r»i
z z x x
H <t <c <£
x X X
O O 2 ;
Z Cl]
ui X :>
CD D H
X 03;
Cl] Q >. Q
H _J
O D U. O
<Z O O X 1 :
XX — SC
S _]
T t/) '-O O
utuo co x
s x a
X S Q
O O' Q Z _]
' 1 . C\J <t m _] <E H
< H Ci]
£ UU1CC
- U3 - 1 ]
u- V H z '
U^hh!
Q Z Z _] •
C NO >J)
3 - NO Q LO
: f'- -j c
> Ci] - n o j
) 7 /) W X o
: o r *a ~ - x
: c >. 3 s
• - - —* CV3 \0 1
•Si £
Cl] o
: z <x x
) •—« UJ u,
. X J X
) U] <£ X
X H U. <1
: u] z o h x
> H 3 HO
Z O H -H
! 3 O Z J H
) O 3 <n
> O X O H <t
] Ci] o 3 J
] £ H
W <X
. H X
T U3 G X £T CO .
Q Q a Q Q Q
C
1 3 |X' LTi X J'j !/) U) !/) 1/1 '/) 7) J) I/) I/) 1/1 U) (/) !^
iCQCCQCQQQQQQQQQQQli]
^->ojn^insssstsisssss , ;sssssssss- , ains3sss(S'HC'jr
c\jcocuajoococo<TLn'Ot^aoo'S — cor)<ri/ivOHcoo'S — coa'cocvjn-q-iovor^rnco o t> ^3 — :
HHHHf«-C-HHt^P*'HC , »P*C0C0C0C00000C0X>00C00'^<>3NO0'0'0'0'0'O'0N0']''>3''':S1
CVJCOCVJCVJCVJCVJOJCVICVlCVJCVJCVJCVlCVJCVJCVJCVJCUCVJCMCOCVJOJCVJCVJCVJCVJCNJCVJCUCVJCVJOJOJCVJCVJOJCVlCVJC^roro
<1 •• •• •• U >• •• •• •• •• H •• •• W *-l •• •• •• •• H M M ••
X —< <\)coq-inNrr*-»c'M:>XHZMi-«<£XXXox QQ *
T r ‘ CX^X-^XXXCOZj^HHXroHQHHiCXJO
C QQCC3CQGCi]O^ZJii]'X<IQOOJ<OH
■ *i X XXXXXTXT>-OCi, 3 XX tQ'tl^CDiXU)
a. 1 l. .l i 1 . 1 .
S ~ T S OSQS'S^'SSSSSSOSSSS'SSSSSSQ
3-*: co iO\CHrocN3-^ojco>TLn\cp~cooNS — coco<ri/ior^cx)
•' 3 3 3 3 3 Si 3 <3 — — — — — — — — — -.CVJ0J030JCV1CUCMCVJCV1
r^r'N-O. - *'. r<i rr\ r<\ r*~‘ rr\ r*\ r^, r*\ rr\ rr\ rr\ r*\ rr\ rry r*\ rr\ rr\
S<TCQQ 3 C 0 -*U. 3 -q- S <S — Cju
(SOCOQ-q-COSt^ T> 3 ) IT) <T tO p-
21'O l IB]'C<tC»DOD''CCOffi'CXE>CI>
QUOQUOQUOQWOQWOQWO
oo<Ioci.-*c'i'Cco<tccQCi.®cv]^uor>ON
— — — -^COCOOJCOOJCOOJCOCOCOfOrOCOCO
000000000000000000
CV3COCU03CV3CVJCOCMCV]CV3CV3CVJCV3C\3C\3COCV3C\3
) 3 3 (S> 3 3 — — — —• — •COCV1COCV3CMCVJOJCVJCVJ
cooococococococorococorococococococorocococococo
in 3 3 3 O 3 Ci] Q U. <T
^ Oj a a q a q q n co
fflinificc'-iooinin co
jo >j <j -q- q co in <1 co
’n 3,Q3CO\OOCOt**Ci]COCO
- cv qqminqmqqinr)
•• u; -* — o fJ o — co u. m -•
■c-q-q , <i-q--q-<r<rin-q--q , co
o'ONWW^ocr'-qos
mqqqqqci/m^inn
x q w w U3 < 1 , QdxQsscuw q"qr>roQCx]u. — co
Vi- c** • O'O'Uicr uaQWii.u.u.isnqqqqqqinin
O OOOOOOOOOOCOOOQQQUlUlCilCdWUlCi]
cuacvjaa-cococvcocjcoojcococococvjcvjcocucvjcococvjco
Number 28
Dr. Dobb's Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, Ca 94025
Page 41
375
BY PHIL MORK
12 Woodland Rd.
Weston, M A 02193
(617)894-7147
Dear Dr. Dobb, Dated: 78 June 13
Here’s an offering for your journal, the Vocal Memory Dump.
It was hand assembled, the listing is from my disassembler
(hence no labels). The comments were added later. For $3 I
can supply cassette tapes of VMD for those readers who
don’t want to type in the program or implement the input
hardware. I’ll include the resistor and capacitor for the output
circuit. Specify Tarbell, Kansas Citv. or Digital Group format.
My hardware is a home made 8080-based CPU board on an
S-100 bus. For memory I have 24K RAM plus another 256
bytes RAM and IK PROM monitor on the CPU. I/O
consists of six parallel input and output ports. I use a Digital
group TVC video and cassette board, and a D to A which I
use for music. My printer is a Kleinschmidt M-311. I have
256 x 208 dot video graphics implemented using a homebrew
interface which uses one of my memory boards and gets
timing from the video board. Software includes Digital Group
Maxi-Basic, Software Technology’s Music System, Wang’s
Palo Alto Tiny Basic and WSFN These last two support my
graphics hardware (PATB has added commands to ERASE the
screen, PLOT a point, and DRA W a vector).
Keep up the good work! Best wishes to you and your
“family ”.
PhilMork
The vocal memory dump (VMD) program pronounces the
octal value for each memory location in a block specified by
the user. As such it is a useful tool for verifying memory
contents (ever try to look at two listings at the same time?). It
uses digitized speech waveforms in the form of a one bit sam¬
ple every 155 sec., which means both hardware and memory
requirements are minimal. It would seem that a one bit ap¬
proximation (ON or OFF) would be completely unintellig-
able noise, but although it is indeed “lo-fi”, it is quite intel¬
ligible and on par with many communications radios. The
trick is to use a high pass filter before digitization and low
pass filter on the “D to A” end.
The Software
The VMD requires slightly over 3K of memory, all of which
may be ROM. It is assembled to start at location 000000
Octal, but may be loaded starting on any other page, then
using the relocator program (listing 2) to fix jump addresses
and memory references. The only modifications which might
be needed to make the VMD run on any 8080 or Z-80 based
computer would be the input subroutine (wait for keyboard,
then input a character to the accumulator), the selection of
the output port (now 013 octal) and a timing constant (now
set for a 2 MHz clock).
The Hardware
To use the VMD program, you will need an 8080 or Z-80 or
based computer with enough memory to hold the VMD and
any other program you wish to “read”. Also required is an
ASCII keyboard interfaced to the computer, the most signi¬
ficant bit of an output port, an audio amp and speaker
(I use a Hi-Fi), a resistor and capacitor. The amplifier should
have a high impedance input (10kf2 or more) and be able to
accept a signal of around 1 volt (the AUX is fine).
Doing It
Connect the most significant bit (bit 7) of an output port
through a 1K£2 resistor and a 0.1 pF capacitor to the input
of audio amp as shown in figure 1. Load the VMD program
Page 42
376
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
(listing 1) anywhere in memory, as long as it starts at the
beginning of a page. If other than page 0, load the relocat¬
or, set byte 000001 to the page number where the VMD now
starts,and run the relocator. Make any needed changes in the
keyboard subroutine (000230), and the output port number
(000117). Turn on the amp, and run VMD. Type in two six
digit split octal numbers: the starting and ending addresses
of a block of memory (any non-octal characters will be consid¬
ered octal, it’s the 3 least significant bits that count). As you
type, the digits should be echoed by a voice (my voice!).
After 12 digits have been entered,the program takes off,
pronouncing the octal values of memory locations until the
end address is reached. The program is then ready to accept
two more addresses. If the voice is too high or low (fast or
slow), try playing with the timing constant at 000121. It
should be OK for a 2MHz clock (no waits).
Your Own Thing
Octal output of the accumulator and digit output (3 least
significant bits) are written as subroutines which can be
called by external programs. Addresses are (000040) and
(000063) respectively. The VMD is a simple-minded program
which serves a useful function, but maybe more importantly,
it demonstrates a simple way to give a computer vocal output.
I chose octal for several reasons: I use octal and hex would
require 8 more digits (another 3K of memory), and there
might be some ambiguity between some of the digits (B,C,D,
although I could use Bravo, Charlie, Delta, etc.). To digitize
your own speech, use the circuit shown in figure 2. Input level
should be around .5 volt, so you’ll need a preamp for a micro¬
phone. What I did was tape the speech I wanted to digitize,
then play the tape into the computer. You’ll probably want to
play with the input level some for best results. Use the pro¬
grams in listing 3 to record and play back speech. I used the
input program to record the digits for VMD and edited out the
space between digits by hand. The sampling rate can be varied
by changing byte 000071. As it stands it samples about 6500
bits per second (or 820 bytes/sec.). I can record about 30 sec¬
onds of speech in my 24K of memory. It would take around
24K to digitize the 64 ASCII characters. If you have a floppy,
you might only need one word in memory at a time while
the computer is pronouncing it and seeking the next word on
the disk. I figure you could get over 600 words on an 8” disk¬
ette.
How about adding speech output to BASIC? Standard vo¬
cabulary might include the decimal digits, “point”, “plus”,
“minus”, “E”, etc. to allow numeric output. Special mes¬
sages for an application could be included in the BASIC pro¬
gram as an array of digitzed speech, or to avoid loading multi-
K of speech, the program might ask you to say “shields
weakening” or whatever during program initialization. This
might also be fun for a conversation-type program.
Thanks are due to Jim Anderson for his talk and de¬
monstration of speech digitization at the April ’78 meeting of
the New England Computer Society.
I
O
*
o
u
U
u
•o
bOTJ
to CO ••
41 4) O
>» C
^ H OH
+* T3 >-(0
•H ” Q .
J • <3
) — </)g
►>
T3
O
£3
>*
45
>
45
4)
C 3
£3
•a
■o
*
O O
c
£ £;
1 u -*-»
l o >»
I <M £3
I £ -H +*
D ao * o
J
<
a
55
CM
® «S
(0
o
55
IO
IO
a
ca <r
—
S
£>
O
u
n
a
CM CL
—
«-•
a
s>
65
G
a
cv
CM
5J
S «S>
6 .
&
5.
u
G.
CM
•—
® X. a
X
G -J
5.
G
o
G5
IO 55
CO
a
to r-
a
*z
5'
<r
<x
<r
<
T 7 *
a
•o
«o
G
_i
CL
-1
<s> • a
*
6 . •
6 .
6 .
GJ
•
5.
G5
•
a
X Cj
UL.
a
m
•
C •“
u. »
u.
•
L «
•
•
—
•
C>
a
5
X c
X <t o
6 , <1
UJ 6
<£
CO
IS
< s<x <
IO l)
IT
o o
S- Oi
X
U-
_J <
O
i»:
ii‘
a su
G
x <t u.
«
0-4 0 -J
d
•»
X
X
X
X
O
X -J X X =» _1
x > a.
-vl >
Q.N O
=>o
u —
-J
r> a c
’SI (Si
in
—•
Z>
—t
<r > x
<1
«
•>
X
r>
o
f-
»-*
O. *v_ X
hJ
x > a
O < 2 U O <
2 O >-
2 O
k. 2
X
•«
O -J —1 2 C
=> ZD
ZD
Cj
c
Ci 0 2
CiC/C
o
r
uoo>
Or
ZD Z>
0 2 1-
2
2 C V
Om
m
x o •- x x u
— XU
X O -3
3
«_>
X cc
u; <r
O
X
OC
i c oz
o
x >* c <
a. a.
a, <i
>■
J 5.*-
—1 X —
y
*“•
_1 X
X
az
O T
0-3 0
TJ
— 20
O
£
io»oirtioioo»nfO«Tiii c\i ir. ?o cm
»o
in in
in
\C
r-
y£
Cs»f~ IO
CM IO
cm
to
cm r*-
O <S> t~-
to If
in cm u\
cm /o in io
in — in r-
s t-
r~ 5.
G.
—
_
5
— Cj <S.
— fO -s
—
<T
a
— U
—•
—
c
a
a a —
vv
X
<s>
tn to a »o — to
a — cm
to —
CO to
IO
O
»o
— Si
es io
IO
a
s. ca
to
— IO CM CO
k;- io
rr
—
a
a -• a
a — a
3
a
a —
a a
to
a
a i«5 a
K5
a — cm
J
&
to <Tt" s> — cm ir\ vtf r-
G» IO
<t tr.
6 .
H
GJ
IO
55
IO
<7 KO
l-~
CM io in M3
r- a
O’
T
u\
O- Q —
CM io
in
(O
r~
a ~
cm io in
(D
a cm io itf
r-
CM IO -sj-
<
<5,
(Si <5i G — —• —
— — —
CM Cm
CM CM
IO
aj
<T
<r
in
If WtCh
r-
r~
n
r-
r~- 55 5.
a a a
a
a
a
—• —•
—
—•
—•
—
CM
CM O CM
c.
IO IO K)
8
a
O 5)
S N.
C-
65
G5 G5
55
G.
(S. 55
G. Si G. G. a 5)
a
a
a
5
a — —
— —
—•
—
—•
—
—
—•
—
— — —
—
— — —
ca
a 65 G G a G
'SQG
G» G)
Cw G.
S,
a
a
a
a
a a a
a a a
a
CM
a
a a
a
a
c.
a
a
a a a
a a a
btf S 8 S Q "5 M
«» G5
■S Gi
G> 6
G»
55
5. (S
a a
a
a a a a
a a a
a
a
a
a a
a
a
a
a
a
a a a
a
a a a
b.
G K> «*L G 55 CL
CC CL CJ
55 S
5J ®
55
GJ
G5 G)
55 55
55
55
a
55 S>
Cw
a 55 a 55
a a
a a
a
a
a a a
a a a
a
a
a
a a
a
a
a
a
a
a a a
a
a a a
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 43
377
s p — c c>, p g g q
\ f) (iKi q p cc to ¥
K; IO PJ e. CM CM ¥j ¥' & IO G ftai
q p vo o: g q «g q vo q
p —■ p ^ g ~ p p <> g *■-• —
— s g to io cm — to g ® g g g
PtiPvtVOiOtOPIOGt' — g
c* k q r- q vi. q — is <v c. Ci t>.
g c\j »o — to —« — g io g c« g g
WMf h h q p — g — g g g
p p p G s. io —b
10 10 K) c - r c io to ro to cm G
io q p q ~ — - ss>6.c»i'j
g — g to to vo c. vt- p p g g <s
GCM— GCM — lOtO — fOIOiM G
g — to p (ve s g r- p — « vo
® *s t p *— p p c* <s q —
fO «-* G «— »0 Ki tO IO <T. G G — C
— g — q in p ip ci ^ g - g >x)
<s p p io to p p p io g g vo —
G IO G G G — S — CM K to — ®
ppppGPpqp q q g s
K/ f. c ts> —• —* — p ¥j SO VO s
K) a w mo s a a a a *o r g
caa—•a-f'SKj^aio s
g c uj w h- q qa io ® a <s
CM K~. K> G — K. C\, a C! a ® c« a
rsppppqpr-pvoGP c.
w • r .K> r~ k> — — — a r a c a
OSSrstOMaiOGCP G
p — — io — to -<-c aN w c
-vpbc. c. <ra<T&r;-(G q
g s a s w — cm r a a a cv s
c*. p p cv. — t' um? a-- to g g
p p p q g — c. p p p
tOfOtOtOtOGtOlO — OCMG —
& ¥.■ ¥i p to q vo p t. g — g g
a s a e c: c g ® io cm g g
•o —
P G
Vi P ¥~ ( M p
p f c. vo * <
. f. ft- ¥ fO fO
- a a c j c»i n
g vo vo p •-
. M*i 10 -* s
- —• U. f' h- f~
t p p ► . —
> G ft. S % g
. p s p g vo
-hc.cr —
)mCCK. e*
— p p t q
- t p — p t-
G — tO tO ft.
q — t' q
P ft ft p p
- r , S G r, —
— *3 % q *
o. t^ r q
- * ¥ <L. ¥
t~~ ¥ t~ q t- •
p ■< r p q
p vi g p io t
vt. P w — C. «
«. ► r • ft K <
e. ft . p ft — •
c * p c. c t
■ a \ f B »•: 1
: p g — G 5 I
r o <■> r q i
— g cm io to >
p *■ q q
r-u. p p c
. ft. s ¥ — G
. t*> g •— f* q
— VP (S h- f- i
G K K G —
' g q r~
r- — — q
— ¥' a ¥
G k* r.
q r~ < t'
^ , — (■/ —•
q v> - '- o
i- vi c r. q g
, ¥. g c ¥ c\j G
a u g
G G P" G O- C
ci esc :-
C S li h M>
u e up
— wlGC: 1
5 vt> r . -.v :j q
p,it<k r — v..»- t- q f» g n g t
h-*-M'^qM i a r-qr-GGGGqG
o K ro O GK. r, K) v w P; rt i 5 5 s C - K>
q
— i^
c —
f' — s^-
» r . <•.. — v
•r f ► • ¥
■*. ' V" *. .-
i* * c c r-
q o r- q —
¥ ’. ¥ f '
vi t- r- q
r- ¥ h- q ;
*j CV —• K
ro -* f > n. (
, ¥. <J c- vt i
. r. ► s. *. «
■ r- q ¥ u
V K C t"
¥• ¥ ¥ 7s-
* 6. G- — C"
t- vl? —
(V — ¥. vv.
. CVMfV
u, — c.
• - M KJ -
r g y£ g w
« r- ¥ r> ^
. fO ^ — Cj
q g g f*~ q
<j? g r* if
<s, g c N V C-
G G G G *i G
C'u G rr G ►. G
5 v£ G f" I" G
r- G G c, G G
K) G CV T G G
<TP !, 5 ' r~
— v cp qp
r S ^ K. K. p.
U — u. r-
u? ¥) c. q r-
o ¥■ -C oi K.
- r~ q g r j if. g c p p p~ ¥ c*
. r- jp q — g f- r- g g- -.
.-nK;C&*-«r,«-isMG
tfP-W' SN<f K.p IT -PSC *{ CCC
r-V-K. L C-wt-q — C»P~ GC- P'GW G q G G
-- G CVJ —• GlVjfOGGGC\jGGGK^G — GG
ipsp-pppsp app cppc <vvx)g
q u > v£) — P K) U'. q r- — P'P'Vl/t^- G G G — —*
G G —• »0 C CO IO K; K' M K KC G G Q S G
h>v6 c « a a a p a p t 6 « a a k cj * g
<f^«»i 0 6 pq««t-i> q g ic g q g g c.
««6iS sionRas^ IO&KJIO - GGG
q l qioapvt-qpvcppppas ^ ’» .v
if if ic-p k cpi- p-r-pccc,!) g q
— <V CJ CV) »C GGrVfOK?GGK. GGG O •—
ir ir it s* k — g r- s a vp ^ (c a is. q g cv g
t'. P- IT' V£ G r- — G q r- r G G G G P' P.
P, ('JP(VCI n lOC('. CP'PICIOCCP'CC
G-qq—K) — P~ qp PPICtfPK'-. *S GG
cvvtacs'fCK.pppqpK — e- g g — r.
-K)-«ssaiocp:oas«-aat.(sa
inciocvwQsasaa®"''. pp r -a c
r-PCVvoujpvDBi qppGPpr q c. p.
SNGNS -K-K. K. C»»«iir C P - — r K-
_ _ G G
c vi/ p — cv) ¥j cv. »o p. r- q — i- g g c g g g
-cjaa-aaiocc-e^csrtces
if«ioeao--RBK5{vr, vc»p p- P K.qr
ItflOCyi-SPP SP «<Mi! <f CPPr GG*— q
«--c\i a nio aicio & b avic c s - a :•
WKiPlO •? rK)P - KCVPP— Gr w. p“ G c
IfiftPWP-CPC. tP PPCvtC GGC.G
--lONioo&ircciciSiiocioio-pjc g
vo k> to K' q p-> ® g q r scsippcs^ios
t'-q cv p — r-PKPP jp cp g o. g g g g
ifi it• to ifv cv ^ p~ r~ p- ¥ cvj q k> g q
c vi/ p — cvj k> cv. to p: r- q — i
¥) r.
p~ g q p- q t
— r- c
¥* ¥1 G. ro ¥’ r
G — P- C — l
— P- — — C_
. CV G C c V
c p- q r p t
r. r- p- — p c
• c. ¥ ¥ , k. .
' q q ci g c
- - g g q
• ¥j ¥) c, CP ■
) c p p p k r
c v p p- v_ r
. c. — — k: g ■
. VO -* ¥ 1 •
• q ^ w c c i
: r.. r ki o k, i
K, p q r* p- -
— ¥ — • P I
Cv. q r. V£» r.
U — U' P- P~ I
¥.¥')¥¥)¥'!
VIP-
t' c.
g r
u — p- — f. t
IT s. P- q r
p. —
G P-
<S —
! co p c wp q p~
q p g p c- p- p
|CIC).0,«|OC.
¥ c. ' —• k> q q r \
o. G ' g • c r.
¥: Cv. & g Ki ^ —
. G VC' P P K P- vi.
• vr< p p~ q t p
> iO CM p-J P-- G K. ¥'
G q q ^ G — G
— p; p c- G vo g
• G cv - cv *0 —
S ic c — p- q vo q p p sj —
VO q q G G P P~ P- C. p-J G G
c »o pi e rcKicccaa
P-GqGGCJP'P-GG — S
— vop-voqqp^GvoqGG
a io o n o sio-iocio
q p- p- p- p- ■? p r, p p p c
p- p. r- p- p- s c c vc c s
ptcioaioscvwsiocv®
G CJ q VO G CM q VO G CM q VO
nioioioa® g g —• — —•
— CVJ CMCMCMOCViCVJCV)
G G G G G G G G G G G G
G G G G G G G G G G G G
IP C M K P 5 iP C
o G q ¥. P- ro VO
G ft.' G K* S ¥< d K.
fO PPPCPP 6
G G P - S P) I' P
CV] G ¥) G l\) G Q P\
s s G P P C to S
G VO C P P VO G U.
cm r <s p)GK' a«
\ \\\\\\\
g _ r^p-r^p-p-r-f'
G -, — ¥ U P — K If
CM Z CM 0 . CM CM tO tO tO
CM 5 CM CM CM CM CM CV, CM
S - G G S G G G FJ
G “ G G G G G G G
G Cl tO P ¥, vi » ¥; G -1
p- g — q L' o. cv ^ g g
— *S- G P> ¥ p, .S S' r» C
v. p p p - p g q q p- g
vOvO’-GPPGPP'GG
fO fO .V G *0 — G to — S) G
■o wpp q — p- sis?
vo p q —• p cm p- g g q G
¥. fO ¥j fO "j G — o. G JO S’
\\\\\\\\\W
p- p-p-p-p~r~ppr-p-p~
P- — tO IT P- — ¥. XT' P~ -- ¥j
lO S G S G — ^ ^ • CM CM
Cm to ¥, ¥. to ¥. to ¥. ¥) ¥, fO
G GGGGGGGGGG
GGGGGGGGGGG
IfV VO CM CM q — P P- —• G
qupif — g — p-c-o
cm o . — g to a & r a g
IfVVOO.. CM — tOGGPP*
p r q K' - p r> — p p
to cv. G G ¥) — to CM* to —
G CM vo G — G P rOGG
to to q tr g vo k ¥. g p
— G CM CM G ¥. G ® O. K'
\\\\\\\\\\
p-ppr-p-p-f^p p-p
= Ii.p-IOITP-IOITP
© O' 0.1 IO ¥j to to g a K
* to to to f. to ¥) q q q q
r GG’OGG GG^GG
~ GGGG G GGGGG
P P P G C O q P O- CM
P-GP&VOVOPPCG.
— 6 G to to to G <S' CM G
— P GP — GGGGG
VOP-VOGGGC G — G
pjlOrOGGGGfOG S
ITG—GqvoPP-G —
Cm G G G P P P G —> G
GGGlMJOGtO — G G
WWW w w
pppppp-p-pp-p-
—• to in -- K/ If P' — K
»-* «-•—*—» CM CM CV O’ K) tO
qqqqqqqqqq
ssaaaaasas
GGGGGGGGGK
IT. ^ W ", P P P ¥ P
to . u vo q r > p ¥> ¥)
rr^c —~:mgg5
g q vO P c q Q G f.
G P PPGPqvo —
Cv] to G to o; IO to ¥' ¥.
StMCv SP C\'«Pf
GGPGPviG — tO
_ tOiO-CJOlOSQW
-\WW\\\\
Z mio in it. ifi to i»‘ ir ir>
u qvoGCMqvoGCvq
^tOtOGGGG — — —
5 q^ if' if it. ir ir in in
r G G G GG G G GG
GGGGGGGGG
If O.
q vo
to to
G GGinPtoqpqtOvop
G GGqif — iro p q G G
to — GfOGtOtOGtO — CvJG
q CM
G —
G G
GPGGP-tOlfiGPGPG
G tO P- G P- G — VO IO >0 P- G
G — G G tO GGIOG — fOCV>
4)
C
o
T3
0
C
o.
o
o
O E
+* o>
o
bC
■M
C
3
O
o
*>
4)
co
P.
o
o
u
41
§
■H
bO
C
o
bO
O. a
4> C
bC
•H
T3
ta
4> 3
> «-»
O "O
T3
»
+J O >> T3 4) G
© "H bfl C
,0 . *H ®
>, > -O 01
JO H
* c r, o
C
* -H
(TO C
U »
- 3 «m
•P U "O *Gfci +> -H
41 £ T3 CO 4) £
bcv « taa ^ «
►»
«
o
Ml
O
4h
O
£5
CO
4) 4>
b C CO
&. 4> -*->
0 > -H
O (0 <0
h in i
to to
CM —
G —
vo q
G —
G G
IO —
G —
G G
q —
q vo
to to
bO •
•H O
T3 O
OS
4)
Q q CM
§
>*
os
o
£
X
z
P- to
— CM
CV CM
CV P
G G
G G
VO IT
If P
CM G
P- CM IT G G P
P If B P CV. P
G CM G G G to
G G CM G G —•
ve G If VO P, p
tO G — — CM tO
6 . — G to G in
g ¥ q if if- —
G G G G CM CM
C ft -CP vf
G ¥ G P- VI P
G ¥) G G CV CM
P- G VO in G to
vr g p — — r-
G G tO CM CM’ IO
g a t. p vo in
CM ft. g in —• P
CJ G to to G CM*
6 - P IO G VO G
g g g q in •—>
G G G — IO CM
p q — to <r p~
p- vo g g q P~
to to G G to CM
Q G P G to q
q g r> g g in
tO G •- G G to
p- to g p q p
P ¥ ■ G P- — P
IO G to — C'J ~
-vop P; C CM
sup vo q u
CM — — tO tO to
p p q pj p ir
pbcppp
--to G G G
— q q «-• g g
VOP il K; p a
t** 1 tO — G IO JO
¥. g p qpp-
tn G P- P P P
GGGtO— —
G p to q -— G
— P VO G CV. G
G to cv: — G IO
P G to G vo q
p — p- q r- p
G IO IO K> CM —
VO P IO P CM P
P tO C - P G ft.
IO — CJ — ~ s
IO CM vo to G q
G VO P G P P
G G tO G — tO
G X Gj
G • G
c < n -r. t r n x
v > a. »v» o. a. Q. p.
Z O 2. Si* C 'O f w-
o2iuoaafl.ir
CMqeviCM-*—— —
cppGvs.0Jq —
io — v\j to to to to to
uvg — CMinvoPG
p - ) q q q q q q if.
G G G G
G Q G G
G G G G
G G G G
G G G G
G G G G
U
q
>-
G
q
G
G p
#o
G
to
G vo
VO
CM
tO G
CM
G —
•—
G
C G
G
CM G
G
G
_1 G G
G
P
q
* G
G
G
•s •» •»
G
G
»
OlUiSffl
G
X CO _I
G
-J
a
-J
-4
•—■ uc pj a:
NJ P
_1
—
a
KU2L
zu:
<
O :> 3>
<t
Z
Q
o
c
JQTQ
“3 CC
O
£E£
O
<
<
i.
Q
— in cm in
CM —
a
m
in vo vo
in
VO
IT.
p
in
iS) — G G
G —
X
—•
q g ir.
—
q
G
tr.
G
G G IO G IO to
o
to
— G G
IO
to
0 *
®
G to q p
G tO
H
G
to q vo
G
IO
in
vo
P
vo VO VO VO
P P
G
G G G
—•
—
—•
•—
—
^ M M
CVJ
CM CM CM
CM
CM
CM
CM
CM
G G G G
G G
G
G G G
G
G
G
G
G
G G G G
G K
G
G G G
G
G
G
G
G
G G G G
G G
G
G G G
G
G
G
G
G
CM
<t G
» G
< < < _J G
Q Q D > O.
M Q C Q O J
X < < T* -o
ap p p p io
— G G G m G
IO CM CM CM — to
g — cm ¥ j q in
CM CM CM CM CM CM
CM CM CM CM CM CM
G G G G G G
G G G G G G
G G G G G G
G
IO »
CM CO
G G O. G
G< G G
G G X G G J
<
to
vo
P G
IO G
CMG -*
G G 00
to —
G —
— r-Gtocvjcvjt^ptov^Pt^
g t. - if. - ^pp q p — g
G GIOGtO — tOGGP, KiG
G VOGqtOGCMG-^IOtOG
g p g to m q vo q in cm q g
CM t^sto — — toto — GK PD
g g p q p to io p q k, p
G GP^GqvO— PVOPP
g si-cvi^-aafiioss
— ?as q g in io vo p to sg
2 a;
a.
3 2 a: i < o w
<
CM
G
CMP — G—CMPtO
io — q
o
“S
Q. — O
-j i_> a. a.
CM
CM
a.
G
G K> — G tO G to
CM CM CM fO
cm in io p
cm m — —
Cd
CM
P
05
q
P G VO VO S IO P
G in <0 P
vo io vo
p — «o —
G
G
a
p
KD G m P G P G
G
GPP
to CM
»o
IO to CM
IO to IO to
G
G
U)
to
G G — CM IO CM —
CM CJ tO G
\
S
\
\w w w
\
w\
vo P —
cm m g —
w
G
G
r
G
G G G G G G G
ft.
G G G
to to
to to to q
q q in if'.
hJ
G
CM
o
G
cvj q vo g cm q vo
¥.
cm q vo
CM CM
CM c: CM CM
CM CM CM CM
ffl
IO
to
G
G G G — — — —
CM
CM CM CM
G
S G G G
G
G
—
—
— — —
G G
G
Q G G
G G G G
G
G
G
G G G G G G G
G
G G G
G G
G
G G G
G G G G
G
G
■
G
G ® G G G G G
G
G G G
Page 44
378
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
SCMCMCMC^^— <TGV 0 -« 7 t-tOGCMvevCGG NQi
GGCM^in cm <*t-vc to t-r-s—c> - r- u> s. o b
CMGGCVG— GIOIOCMtO— CMCM — Si — IO CM G G
GSvcs^vcinGvet- ^ -• sssGSvrveiof-vcinvcGc;
®—intovcscvif'iosst-t-GGGGSt-G — * ^ cv o. ®
G. — G — CM CM — (OfO®lOirtOQ6 5-Q5iCii-t\J-W«VBaS
CMCM^IOGinCM^ — Q <Th IO S G G> G
g — ®cucMCMt'~t-inr-»o cm cv g <r g g
® tO — IO CM CM IO — CM (O IO ® G G — G G
GCMCMint--«TCM»oGt-t-«Tr- g cm ® ®
GSGCM — PO — — P7®®tOP0 B 5l S 5»
CM CM — ® m CM <7 IO IO G — PO 7 IS B S B
<? S&8S
G— GtOGGCMtOCMIOCMtOGGGG®
Q CM <T Gf-t-* — vC — IOV0 Q MS 61 S S
to — -rinvet-'C-q’tot-sp. c-t-os
Q _ CM — — —— — — G — N(0 SB 6 S
g^cm — vet-to<*«r®r-ve<TGGSG
vc s ® ® ®
S«C\lS-*8-®-W®KW - S' ® ®
gg — GCvininvccMr- <r to p- cm ® ® ®
sinr»CMCMCM— < rir>f-mGtove<TGG
cm — to cm — — B^SQIOS^CXISSlS
^ra — —r^cMcvi^r—s u? ® b b
IOG tniO<T<Tin — IT'S — VC ’TW SB S.
®Q®W--K)(\jniO®KMOSiQ(iS
gcmgc— vc—cut—CMr-r-r—t-G®®®
--BC\i- < TU''IOK)r'S--SQBB
GCMCUGtO—CMCM - — CM — —tOGGG
IS G in — Ifl ® ® K) C\l S S G ShRS G
eswQ-ifiws-KiBtfK.winsss
a-,-®—swnioino - s s s
QCVl*-»^U>Slf'^*It'^>OhSSS&
cm m g g to cm — <t vc to it cv. t- ® s — ®
G G CM CM — — — tO — CM — CM G ® G S '"2
RCVSir^VtflO-IOSSf'-tfSBS
BBWSSMf.-h-SBB'lOh-SBB
as - -SIOIO- SSIOSIO - GGG
WB-miT'Cl'TCVBGir'B'rCN’&BS
G — ®r- — GtO'JCumr-t- u? b s s s
Q ® Q - — — CM »0 — (O IO IO 6 8 8 8 8
«ts®' 3—c\j»oc\Jir, K) — f- — <ns n s
S— ^mGIf. CM— VC — CMtO S W 8 W 8
G — G — SI0CVII0®C\JC\)8S»0(8SQ
GG'CSiriO«TVC < 7 < 7GGt-(OSGS
B S ^ GGGPOPjCMiOvC ^MOSG6
® G CM IO IO — CM IO — IO(\MOK)WS8Q
QQITCM— «y)lf'C\I^^WP''^SSS
S «? s g to if. ?o vc t- p;. r- vc s «» s s ®
w asions-»s wnio - s — ® ® g
_ \\\\\\\\\\\\\\\\\
- vClCVCVCvCVCVCVCvCVCvCVCVCvCVCvevC
* _ ko in t- — to ir. r- — to in r- — to in r-
* S, — — — — CVICMCMCMlOlOIOfOGGGG
® « _ — _ — — — „ — — — — — CMCMCMCM
s r- <r vc to <7 p> <r <7 g g ir cj ®
s U/ — a . - cu — b G <r vo u'i is
S S K) - 8 8 — IO 6 S CM®® —
IS — <7 VC CV S C\) B & B G VC VC —
G V£ P m P- <7 f-<J G g cm to ®
®IO~tO — QtOCviSS CM — CM®
® cv <r vc cm ir. cm in s g <r cm in
B <r B W <T tn G CM G IO g g m ®
GIOIOCMtOCMCM®— G — IO CM G
is. — cv. <r — ir ai r~ — »s cm cm ® tn
G VC *? IO vC C< 'MG.C.G. g — — cm
® ® — — to — S G — S CM CM — CM
G G P IO CV CV) — IT**® ® p- cm r-
5 — VC If t- — CM CM C. S' <7 CM — P-
G CM — — — tOGCi — G ® to — to
® BIO - to <T CV1 S ^ W <T CM m *7
G S VC IO — IT — G CV -<7 G CM VC
GGSGCMlOGC'—G — G G CM
SGU. — tOCMCNJlf <T — G «7 <T CM
6 C. <1 CVl ^ B - B If . B G CM CM G
G ® IO CM — G — (MBS ® — G CM
ggvc — ior-c\i^ — — ® «r <7 r-
® G 'J— — — -5TtOM)Ci B <C lO U'
BB-S--SC' vS G G G — G
SSO-CMB<7-BK) G CM P ^
G G VC G If. IT. <7 If . CV vf S - O’lA
BBS— CMBMMa— CM G G CM
GGG-TCUVCGt- CM G ® G If. IO
S G P — <7 -T - IO G — vC G VC — ®
GSCMtOfOlO — CMCVCM GGG —
G G P <7 — <TM5VC<M<T G CM CM —
GG — — If. VCPCMG — CM G <7 vC
G G IO IO CM CM — IO CM CM —lOtO —
C.S — VjCMinCMVC — GX ® — G CM
tsGvcvcin-^to^inG— — <7 in cm
gg — — r — tCGtO — ® gcmg —
g g> <r to — r- «e g cm vc g g in <7 in
G G to I-G — in If. <tt — — G to <7
8 B CV 8 to SO - B BC CM G G —
— ® vc vc — m s in to in cv cj in ®-m
S G — — P P — CM IT -7 0 ® — — ®
G G IO — CM® — GGG® ® ® ® ®
s g p — <r ^ vc cu to — in m <r m ®
GGVC4— VC® — »M«nCM - 0; CM — 1C
— iOCViOCUCMiOR® c G ® — CM
\\\\ \ WWW „ \ \ s\
VCVCVCVCVCVCVCVCVCVCVC > VC VC VC vC
— toint" — toirr^ — to it. ^ in r- — to
___,-,£\jc\JCMCMtOfOtO to to to ® ®
CMCMCMCMCMCMCMCMCMCMCM z CMCMtOtO
cm t- ® r- vcr~tovc® — vc®r- g®
sinintor-®s®vc — ®vc — vc® -7®
CMCM — ®®tO — ®tOCMCM®® — GtO®
®t^to®-«T®r~®r~rovctr\r-^to ®® —
— toinGr-^r^sr^vcGG-vyrow ®g®
— —CMtOfOtO — CMIO— ®® — ®f) ®®®
OJBCMM^Qr-vdSBtO^MO^ CM ® in
CMto- 9 ——veto—-^®® — *7 r~ r- ® t~-
— — CM — ® — GtOtOCMG — Gtoto ®®CVi
— Qins^TvCQtOt^CM^r — ®‘G h- ® h- ®
inCMG-*®t^G* , t-G'— — ®h-G
®®®tOIOfOCMtOIO — tostoto ® ® — ®
— to CM VC vc h- — K 10 t~ Q <T S *T G G G ®
tOCVl^hh-^VCSh GGr-lOCMGVCm
to — — — * 0 ®t 0 » 0 t 0 t 0 — to— ®G®CM —
«r»nr~®r- <r<r^®ro®to® — *ccm®
toG^^r^Gh-tOf-'r-ir.G — ^r-t-iSG
®®CM®OtOIO®tOlO — COS — — GG®
r-CMG— Sh'f-h'r-vC—CMC^GGG ®®
BromB<7iM-— —SGvx-r't- ® <7 ®
®tO®®tO — —®®® — G®tOCM®K>®
m^r-cM — to ® to t«> if cMin-^vcvc<TG®
cm cm to r^- r- <7®®®to — 7 t'f'" 10 ®®
— — ®tO®— OtO®G ®®(V. *OG GG®
r^CM — tO®®r- — 8lOhM'<T6b ®G
VC<7CM®r-vCtOvCr'CM®GG — ®U G®
® to — ® to to ®tOtO®G®G®®tO®®
®r-®®vc®r- — vcr^G-^mf-t-GGr-
it«t r- — t^r-r'GGGr-r-vCGt^
QGGCM— Qto®—lOvM — — ®GtOG —
veev— <r<7<TG<7r-®Gvcr--r-r-<7;sG
— t^|f\t~-Gt~- <t f- IS < TGt'~r~ — — f' GG
tOGtOGGtOtOIOGtO ® to IO IO IO GG®
® CM in S VC t' ®
tOCMVCI'-t'- — vet^vetOGve B 7 - B B
®G — ®tO®—— tOtOG— GtOtOG®G
mvMr-vcr-®vctof~c-ir to®«s.®r-G®
cM^t^r-^rsf-Gtor' g cm r- r- n- g g 7
— trCMCMGIOtOGG — IOGIOGG — G®
mcM'er^Gt'-f'iOGvcGG — g — Gr- ®
h-h6UIKM'68h7B-78'Ch ®
tO—— ®CM— ®CMtOfOCUCCGGQtOtO®
<T®vC®®r^®G®*>«— Gin — tOt^G®
to IO M vet- <7 G r- 7B77l r Jf'8t r -CMB
to GtOtOGGCMtOtO SOB ® — tO GtO G
\\\\\\\s\\\\\\\\\\
VCVCVCVCVCVCVCVCVCVCVCVCVCVCVC VC VC VC
int- — tomt-—toinr~ — toinr- — tom r-
G® — — — — CMCMCMCMtOtOtOtOG GGG
IOtOtOtO»OtO»OtOtOtOtOtOtOfO<7 *? <7 «7
GGGGGGGGGGGGGGGSSGGGGGGGGGGG gggggggggggggggggggggg
rj v>; u r- if, o c . v* g ® e <r
K- if y . (1 - 6. r- l» B G CM G
G to — G G CM f G * CM — G
t--CJ-7t BBS - ® — CM
r-Gver-uV — G ® G G GGG
to cv to to 10 G G 'i ® CV G — G
— I- — r. —to G G
v_ r 7 \ Mf! B VC <7 G
CM — CM S P. to CM GGG ® — ®
vc c r- r- t- b. g *.* cm p ® ® in
vCP r-t-C-GB GG— CM — ®
G K- to CV p S rs BUB G G CM
to vc r f O M — I v - _ G G
10 r. — t- v .• s <. •> cm to —
to G K r p- — r .. ..M -V — CM G
sc — C» K t*i •■'• G K . n G CM CM
N o <v s — c- Cl 4 . C CM G m
® K G C. S r i Cj G Cv — — G
IT 7 - 7 C TIT 7 r . - G — G
r- M:r c r- w p~ p j- vc g g
*0 •? . K. f . — — C: K G G — G G
— t- U G — — Z, r. B S CM CM
.t-UGP. GGPV-SG G — «?
CJ f — Ol B S S 10 B S GGG
r- 7 r- r r-r-o s-cmp. — g to
r— vcp C 1 C v — Ps. CM G ^
— C‘ C. P" ? C f —PR G — G
'< I- 7 7P'f <V (S - — G CM
B - u»h p C. Mv 6 6 — G CM
P. — f f p *• — G ® G — CM
tovcr-?cvr-— p: p* - ® — ®
to f- C'. ® ® I- S. <S — s G CM G
cyjr. scvfssssQ to — cm
P. ■S<7r-t-V£<TCVC.G — G
P CBl-t-t-r IT — B B VC CM G
GGPj— CtOCVG — G — Q to
IT <r f> C\ — — SIS — G G-^tO
7 K. 5 P P B U B vi 8 G G VC
— ft.aiRP’I'^BBS G — G
cvvc®r-tot-t-r~®r-—tor- Gver-t-
7 — BP GP tJ - P - S B p. <rr-t-to
— — ® tO 10 IO ® G to G CV GGtOG — G
G— VCGVCGIO® — <T r~ Pj t- t- ® P> —
SB-6PBBVDBP77-PPSS
G G — to to CM CM to 4.1010 rt G - — CMtO
8K'8PPBP'f7-BS8IOB'CP
— tn®t- — r-tot-r-G^i-t-
GGG to® to CM — tOStOtOIOP)PJP)P)
to-® 78P s «Tr-<7 , r-t-r-r-r-t'-ve
GtO — POf- — G — tot- — — t-t-GIO —
GG—tOtOGCMGGtOGGGtOGGG
8SP8P68MOPS8BIO-86
VCB78P 7PP ® — -^vC<T®-«T^t-
G CM ® G G tO tO GCMGtOIOIOCMtOtOfO
CM — vc to G P- t- tot-—-vrveveGt- Gt-
BtOBBPt/P; G — 8PPP7 — veto
GGGGtOGG GGtrtO — — tototo®
-7-7PI078SPS'C7lOlOvC'H
vc to vc — t- g r- ® g to — r-
GCMGCMGCMtOtOtOGGGGtOCvjtOCM
GGG <7h l- P IOvCGf—PVCG—t— —
— t-VCtO — 1-10 BP7PP P 7 7 S
G G G G ® IO G G — IO— GGlOtOGtO
G — <r — <r — — g Gt-toror- gk>gp
Gtoto^t- ® G t— ® t— G G G t— ®t- —
G CM CM — tO CV CV tO G — Q C: G — CV IO CV
*7" 7W-PBPPP5 <tp:p to to p g
G tO<T<7‘tOV£7P'. t-t-Gt- ^Gt- 7P,P
G — CM tO G tO IO GGCMIOtOCMGtO GtO
W88S5P8PIOPB67 6PPP
®— U/G^tOGGGP-'GVCvCvC— ®P
G CM G G tO G tO GCMGGIOlOtOGGfO
IO-VD8PS8P8SPPP6S7P
VC — — CM I- 8P tO 7 P B P. P 7 P S
G G — G tO tO tO GIOtOG®GtOtOp)CM
--7P&PP — — <* — GGGVCt— G
r-^cMG^r- — G-^t-Gvcvcvet-r-to
GGGGIOGGCM — tOtkllOtOIOGGCM
GGG — IC 5 SPS 7 P 7 P
GG— CVGvcvCtOvct-rOt-G
G®G — GtOtOGIOGGGtO
vC— vCG — mGPtOGt-tOlOVC
8 7 P *j SBIO— SW 77 W"
G — GG — IO — G CM IO — 10 — G
P 8 P B — GGGtOVCPvCPG
— G G 7t)87St:S877
GCMGG G — GIOPjGCMtOtO®
G — t— <7 — 7 BVCIOP - G — G
®G- CMGvct- ^tOCMt-vCt—
tOGGG GGGfOtOGGGto —
t-G—® — ®GP«rp— top- s
t- G G G — CMt-GPG<TvCGve
— K, tOG GGGGtOGtO — tOtO
B Pi S 7 GG^TG — IO-«TvCVC —
GVCVC— GVCGVCVCGPIOP. VC
® G tO G G tO G IO IO CM IO ® G CM
Gr-ojr- GG — G vc — vc ^10 p
VCGGG 8 N 7 «P tPtO 7 G
tO CM G G GG— GlOtO — GiOlO
t- — G — V<r^t-t-Gt-tOl-G
— vc VC G GGG—tOGIOGGVC
G — G ® G CM — GGtOGptOCM
& 7 B IO NSIOP « 7 PB 7 -
G IS G IS GGvCGGPPjPfO <7
CM tO — CM G — — G 10 G IS tO U IO
G G VC — 8-88 —MO—P «
VCVCGG —B—B 7 P- 7 WP G
IO — S CM GGGCMtOGtOtO — tO
vCGGG 86788 PSICWP
— -T®-^ QSS 57 S 6 PjP, -
® ® — G G CM G tO ® IO CM G CM
<TGGG 88777 P 87 -VD
PV B 8 7 G—GGf— G f- tO VC P-
GGG— GGGGIOCM — GGG
f-<TGG G G G CVJ — tOvCt-tOvC
P- CM G IO QS 767 BP 67 -
— GGG Q — GGGtO — tOtOG
B W 8 G CV 7 6 7 Ui B GGG CM - ^®
VC PJ r— P ID P P P 7 8 U) r. « GGG
tOG — IO — CM® — ® — GGG G — G
7PvCG877PG«f?8Q6IOvCW
PGPver- r- to — t- P B 7 B CV 7 w
GGCMtOGtOGG — — S — GGG®
SVC877P«)P7r —GG CV tO CV
t-—c- - P Pi - BP G GGG CM G U
-68810668100688866
— GP^VCCMVCVC 76 7 B6IO
G — PPVCPGG — VCt.BB 7 7S
CM G — — — 8P(M6P)(\86WS-
-PU3 7(0 PtO t VCP — <T G CVS®
<Ct';PPS-7B--BBBB77
tOGIOfOCMCM—GGGGGCM SG®
IO 7B 7P P P1IOP G GGGGG-T G
7 P) P P t B 76B 7VCCVIB BB7 8
IOG — —lOCMlOCMGtOIOGCV—GCMCM
-G7PIO 6-81086108 GCVGG
CM r- in — vc G'VCVCGVCVCGG G CM G CM
G — IO GlOIOtOtOCM — — G — ® — tO G
tOvCPP®®— -sr — CV'GGvC GG® G
7P77VD 7BPBP 66B B77 C\l
tOGGfOtOtOCMtOtO ® G IO — G — v\) G
87»DP8P)-W8P G to in <T — — <7
topto — 7 vc 8 P) v/> P G G <T G — IO —
CM G G CM (0 >0 IO G IO G ® G G C- S Cv. G
— Pt-toto — to in VC to ^ G CV 7 CM G G
VC — 77<TvevetOP®tOGCMCV7CMG
IOGGIOtOIOP>GGCVl®®® GGG®
(MVCVC87 — — — VCP —t-G GGin —
<T IO — IO t- vC VC G G tO G t— G G G vC CM
tO GCMCMGtOtOCMG G S G CM GGGG
P SPP7l0 8- (V'r GG G 8CV17 6
VCVCVC«TPGVC — 76W6666CVIS
— G — tOtOCMtOCM— CVCMIOG G CM G CM
*-. VO Mfvsp CM VO G G P — G GG— ^
— PIOP-.VC — VCGGVCCMGG GG — —
CMIOGCM — IO 10 IO tO tO ® — G G IO ® CM
P-7KWSP)-WQ G G ^
P P/ Ifi Q cv bt to IT 7 G GG —
IO to s G G — — G CV G GGG
G CM — G VC t- G 888QiC^778P VC
8N»C8PGPPPIOPPPP-7PIO
G ® — IO IO G IO tOtOGIO—— tOGtOtOG
GGG 8868718PPS7
GGG — CMGGPvCtOGlOt-
G tO — G — — GtOtOSCMtOG
GGvCP — tOVtovC — tO^T — G G P VC
IOPIOGG 7«6PP 87 6 IO 67 6
G — 6P)Wl08t0P)88t088W86
BP-S-WBB CMCM
Gu.— VCVCG SG— CM
CM G ® CV CV! G — G G G
78-8-78VCPPP
GSGmsr-Gst-ioio
8 B- -.08 8 610 8 G
PIC8VCVC87PP — G
— r-ve — ioppps68
8--888-IOCV16 G
g G g g * r-
® to G CM G G —
G G G G CM CM G
Gt-— GtOvCCMGG — —
7®vCvCVCtO <7 r- vCGvC
IOGIO — (OGtOSGtOtO
vCGr- ® G CM — G CM — —
PvflPIfVPiCS 676 7
G IO. G IO tO — G — G G —
r- intOP-scMirt-®G
r- to t- c\. ® cv u r ■ m — s
— tOCMGSJIOG® — G
\\\\\\\\\\
ininjAinininininirtn
VC QfM 7 & (V 7 VC®
-CVJCVICVJCVOIOK'IOB
in m it tr. it- in tn ir> in vc
GGGGSGGG GG
GGGGGGGGGG
•® — GG^G — t- — 7SP7PP 7PVCGV
i G VC ® — tOGGGGPGGPIQlOP — — t-t
•GGGtO—CMGGCMtOlOGtOGGtOGGlOP
.\\\\\\\\\\\\\\\\\\\'
r777777777 7777777777’
J7VCSCM7VCGCVJ7 VCGCM^TVCGCM^vCGC
1ISG — —— — CMCMCMCMtOtOtOtOGGGG— >
>vcvcvcvcvcvcvcvc*cvcvcvevcvc PPPPPP
tGGGGGGGGG GGGGGGGGGGC
IGGGGGGGGGGGGGGGGGGGG
i«MP8 7P7PVC»rvap 710 8f
r 7 8 op sp 7 P)Pt-itovc *r r
B — G IO — CV IO tO GG G G IO tO PO I
‘NN\N\\\\\\V\\\'
)P>lOtOP)tOP)tOlOlOlOtOIOlOtOI
rvCGCM 7veGCM *7 VC G CM 7VC GC
JWlOlOtOP)8S68 - — — — CMC
t-t-t-t-r-GSGGGGGGGC
iGGGGG — - - —
tGGGGGGGGG GGGGGQ
Number 28 Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025 Page 45
379
Page 46
380
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 28
COSMAC Elf
Experience and Comparisons
Dear Doctor Dobb: Received: 78 March 24
Your magazine is always a welcome sight whenever it does
arrive. Keep it up.
From time to time you and some others have published bits
about the 1802 micro and the ‘Elf computer. Although quite
underdeveloped, this seems to be the lowest cost way for a
youngster or beginner to start.
Two days a week I have been taking my Altair to a private
school to expose the youngsters to micros. One student
became so excited that he wanted to build a micro from plans
in a very old issue of Popular Electronics. I explained to him
that the later issues of said magazine have a series of articles
on a much easier, lower cost micro-computer: the ‘Cosmac
Elf. He came to the conclusion that it is really cheaper to buy
a complete kit rather than one piece at a time.
Presently there are, as far as I know, just two good low-cost
versions of the ‘Elf. The ‘Elf II’ from Netronics R&D in New
Milford, CT, or the ‘Super Elf from Quest Electronics in
California.
Which is better? Well, Timothy bought an ‘Elf If for a little
over $100 and I got the ‘Super Elf for just about the same
price. They are both good. Almost equal, but not quite.
First, the common points: Both are about the lowest cost
for a good micro-training tool. Both use a single P.C. board
with the 1802 processor, 256 bytes RAM and a nice hexa¬
decimal keypad and led display.
The power supply is a single 5-volt regulator on a heat sink
fed by four rectifiers and a 1000 Mfd capacitor. The step-
down transformer is external so that no high-voltage is present
on the circuit board. You must order the transformer separate¬
ly for the ‘Elf II’. Don’t be foolish and try to run it from a
6 volt transformer or a bell transformer. The power supply is
very weak and you must have the right transformer for good
operation. About 8 to 10 volts AC is required. 12 volts AC is
too much and will overheat the already hard-working regula¬
tor. 6 volts is not enough.
The reason is the hex display. It uses as much current as
the rest of the computer. I have modified my ‘Super Elf so
that the average display current is reduced by giving the led
display pulsating D.C.
Both come with good assembly instructions, but some
prior knowledge of electronics is helpful. Although Timothy
has not ever built anything like this before, he did quite well.
The main problem was trying to make modifications before
finishing the kit. He now has it up and running and inside a
very nice formica cabinet his father made.
Both dealers promise additional devices for their ‘Elf kits.
Adding an I/O and 4K of memory will amost double your
micro-computer investment. Still, it is about the only way
you can get going for less than two hundred dollars. Now
about the differences: The ‘Elf If has a larger board and has
lots of room to expand, while ‘Super Elf is very crowded on a
smaller board. One pad is provided for a standard 44 pin
connector. If you wish to expand you must directly wire into
the 50 terminals on the upper edge of the P.C. board.
The power supply transformer is included in the price of
the ‘Super Elf, as is a simple monitor on ROM. However, it
is very limited. You might like to have an address display. It
is available as an option for the ‘Super’. No provision on the
‘Elf II’. The hex key pads are almost identical on both, but
Timothy and I agree that the arrangements on the ‘Super Elf
is more logical. So he rewired his keypad so that ‘0’ is in the
upper left and ‘F’ in the lower right. ‘Super’ includes an audio
amplifier and speaker for the ‘Q’ output. First thing I did was
to try a music program which was not very loud. Timothy has
built his own ‘Q’ amp and used a larger speaker for much
greater volume and better bass.
My ‘Super’ came with large ‘500’ type seven segment
displays. ‘Elf II’ came with similar but smaller displays. The
‘Elf II’ can not single step a program. The ‘Super’ has provi¬
sion for either single step or running a program slowly as an
aid in program debugging.
To sum it up: ‘Super Elf appears to be the winner,
although ‘Elf II’ may be easier to expand. Both are a good
buy. What is needed for both kits is a modification to use a
1702A PROM.
What the ‘Elf needs is a good prom program to read data
from a Kansas City cassette and write into the ‘Elf’ memory.
Tim uses the cassette program published in Dr. Dobb’s. He
first keys in the Read Cassette Program, then loads in his
favorite programs via the cassette. I knew that it could be
done, but the first time I saw him do it I was spellbound. His
entire system cost less than the cassette interface for my
Altair. This is a good example of the cost-effectiveness of
micro-processors. The 1802 doesn’t need a UART or fancy
interface to load data into memory. Just a few simple parts
and a short program!
The 1802 needs more software. I am going to try my hand
at writing a Tiny Basic for the 1802. If it turns out OK then I
will make it available to other hobbyists on cassette tape. I am
using the Altair to cross-assemble to the 1802.
Maybe it sounds like I am down on Netronics. No, not
really. Be aware that what you get is not exactly what you see
in the photo. The 86 pin connectors are extra at $5.70 each.
And the four buttons on the far right may be replaced by
toggel switches. And not all IC’s come with sockets. Both kits
fail to use the required 22K pull-up resistors needed for TTL
to CMOS. One of our units gave some trouble because of this.
Yours truly, P.O. Box 27462
John B. Palmer Tuscon, AZ 85726
Number 28
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 47
381
Dr. DoBB'S joURNALof
COMPUTER
(Calisthenics Orthodontia
Running Light Without Overbyte
Number 29 October 1978 Volume 3, Issue 9
A REFERENCE JOURNAL FOR USERS OF HOME COMPUTERS
SOFTWARE
LEDIP: A KIM/6502 Line Editor Kiumi Akingbehin 4
An expandable program for creating text and source code
Quick and Dirty Routines for BASIC Dennis Allison 13
Subroutines to implement some useful functions
POW: An 8080 ‘Processor of Words’ Herman Watson 18
Whatis: An 8080 Expression Evaluator Mike Gabrielson 34
A program for evaluating arbitrary arithmetic and logical expressions
HARDWARE
The Digicast™ Project Jim Warren 16
A broadcast-based information system for the public
Data-Boy™ Speech Processor James Anderson 30
Description of a new, low-cost speech interface
© David Dameron 1979
EDITING TINY BASIC
A NEAT TRICK
Richard Greenlaw Received: 78 July 24
Here is another extension for Lichen Wang’s Palo Alto
Tiny BASIC. I have modified the GETLN routine to allow
editing of existing BASIC program lines.
To edit a line, type the line number as usual. After that
each control-L (the load key on a Sol) will input successive
characters from the original line in the program. You can
backspace over them or blend them with new text as you
like. The line can be terminated by carriage return from the
keyboard or from the original line if you go that far with
control-L.
If the line number doesn’t ejdst a line delete is simulated.
I typed a source from the Interface Age version (12/76)
so I added this by reassembly, not patching. You will note
that I have changed some of the control codes, such as line
delete, and have replaced the RST single byte calls with
normal calls so I can run at 2A00H under Micropolis MDOS.
A
G£ I LN
CALL
OUIC
lOUlPUl TROi'i A
kJ w32 A
AKA
A
izeko
AAJA
STA
EUFLG
IIiMoICAIE ED 11 POl.MlEK -MOT *|
A A A A
LX I
D#BUFFEk
AA50
GLI
CALL
CHKIO
A AM
JZ
GLI
AA1A
CF1
0CH
JCTL-L (LOAD kEY O-m j^l)
A A H0
CZ
GLEI)
J GE 1 CHAk h kOi»i OhlGlM.AL LIME
0 09 A
CPI
7FM
A 1 AA
JZ
GL3
0 110
CALL
OUIC
A 1 dA
CPI
0AH
0 I JU
JZ
GLI
A 1 AA
Oka
A
0 1 b A
JZ
GLI
0 I 60
CPI
1 bH
JCTL-X Is liNE DElET"E
A I 70
J L
GL4
01 HO
S TAX
O
0 1 90
IMA
O
0 dAA
CPI
CR
Adi A
*2
Add A
MOV
A# E
A dAA
CPI
Ah h h&HiJFEIML)
A'dAA
JMZ
GLI
AdM
GL3
MOV
A t E
AdbA
CPI
0FFKAPHJH EMU
A'dlA
JZ
GL4
a dm
DC X
1)
AdVA
MVl
A,SFH
0 300
CALL
ourc
0310
JMF
GLI
0 320
GLtO
PUSH
K
J ED l lOr?
0330
PlJ4H
IJ
A AAA
PUih
tl
0 3 b0
a 1 AA
u
JUcLlMll fakTIhl i.mPJT
0 3 60
LDA
EUhLG
0 3 70
OkA
A
A 3 60
J.MZ
GLEUA
j n* ptr imio old line set
0 390
* F I .Ml)
LINE WnObE MHk
BEGINS i MPuT LINE
0 400
LA 1
l>» KiJFrEK
04 10
CALL
Tb T.MIJM
J ML = tt 1 MAk Y LI Me. * 0k A
0 420
CALL
FiMULiM
IIJE- >L 1 ME lh L b£ 1
0 430
MV 1
A » 1 hrl
ICIL-A Li.ME DELE IE
0 440
JMZ
GLEDX
J Ih MO 1 FOUND C4MCF.L LImE
0 4b0
I.MX
IJ
JSKlP HIMAkY LIME Mok
0 460
IMA
u
0 4 IA
ACHG
04b0
bHLO
EDP r k
MMIIIALIZE E.Jir POINT EK
0 490
MV I
A* 1
0 b00
b IA
EOFLG
JlMUlCAle. EDIT FTP bET
0 b 1 0
Gl.tDA
LmLD
EDP 1 K
; Ed IT fOINIEk
0 t>20
ho v
4 # M
;pk0i*. 0 PlC INAL LIME
0 b 10
IMA
M
0 -340
SHLU
EUr* 1 R
0bb0
GLFIJA
pop
rt
0b60
r'OH
IJ
0 b 74
POP
rt
0bti0
KE 1
0b90
GL4
CALL
CKLF
0 600
MV 1
A»nEn
061 3
JMF
GE TL.M
b4b/>
Lsr*"
E«JU
5
Vn 1 )
EUFLG
u.b
1
I ED I I ADDKE.bb SET FLAG
b 4 60
EOPT
Db
2
JED IT P n 1 NT Ek IN 10 ^kIGImAL
Dennis Allison Received: 78 Aug 11
This trick using the Decimal Adjust instruction generates
the ASCII character corresponding to the hex digit in register
A. I first saw it in the Intel MDS monitor. Ken Burgett tells
me it was due to Bill Byerley. Both are with the Intel software
group. Assuming a number between 0 and 15 is in the A
register,
8080
ACI 090H
DAA
ACI 040H
DAA
6800
ADD A, #$90
DAA
ADC A, #$40
DAA
gives the characters 0 through 9 and A through F in ASCII.
Just how it works is left as an exercise for the reader.
16 BITS FROM CROMEMCO?
Reports are that Cromemco would be developing a new
CPU around Zilog’s new Z-8000 16 bit microprocessor which
will be sampled this year. A call to Cromemco netted a sincere
“no comment” with the additional remark that Cromemco
was “looking to develop a family of compatible machines.”
We’ll be watching. -TRW
PUSHING 8080 REGISTERS
Mike Gabrielson Received: 78 July 27
It recently became necessary for me to devise reentrant sub¬
routines for pushing and pulling all registers on the 8080. The
push routine turned out to be surprisingly difficult. Can your
readers construct a more elegant version?
1
2
Pusher - reentrant
routine to push all registers *
3
Mike Gabrielson
7/24/78 *
5
6
0000
E3
’usher: XTHL
jswap HL for return address
7
0001
D5
PUSH
D
;save D, E
8
0002
C5
PUSH
B
jsave B, C
9
0003
F5
PUSH
PSW
;save A, PSW
10
0004
E5
PUSH
II
;put return address on top of stack
11
0005
210800
LXI
H, 8
;get offset to stacked H, L
12
0008
39
DAD
SP
;HL :* address of stacked H, L
13
0009
D5
PUSH
D
;now we need DF, so save an extra
14
000A
5E
MOV
E.M
;E :■ stacked L
15
000B
23
IN X
H
;point to stacked H
16
000C
56
MOV
D, M
;D :■ stacked H
17
000D
EB
XCHG
;restore HL
18
000E
D1
POP
D
{restore DE from extra copy
19
000F
C9
RET
20
21
It's unlikely.
but
if the stack is situated so that it crosses
22
between 0 and
FFFF,
then the DAD instruction may destroy
the
23
caller s carry
bit.
In that case, the following longer
JUt
24
foolproof version is necessary:
25
26
XTHL
27
PUSH
D
28
PUSH
B
29
PUSH
PSW
30
PUSH
H
31
PUSH
PSW
{save carry before DAD
32
LXI
H, 10
{now the offset's bigger, too
33
DAD
SP
34
POP
PSW
{restore carry
35
PUSH
D
36
MOV
E, M
37
INX
H
38
MUV
D, M
39
XCHG
40
POP
D
41
RET
42
4 3
45
Puller - reentrant
routine to pop all registers *
46
pushed with Pusher *
47
Mike Gabrielson
7/24/78 *
48
49
50
0010
E3 Puller: XTHL
{swap junk for return address
51
0011
FI
POP
PSW
{ignore junk
52
0012
FI
POP
PSW
.•restore A, PSW
53
0013
Cl
POP
B
.-restore B, C
54
0014
D1
POP
D
{restore D, E
55
0015
E3
XTHL
.-restore H, L and stack return address
56
0016
C9
RET
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 3
385
LEDIP
A KIM/6502 Text Editor
BY KIUMI AKINGBEHIN
Department of Mathematics
Wayne State University
Detroit, Ml 48202
LEDIP (an acronym for Line EDItor Program) is a general
purpose line-oriented text editor program for 6502-based
systems. LEDIP can be used for such purposes as writing
letters, preparing texts, and generating source programs.
LEDIP is designed to be memory-efficient and easy to use.
Residing in about IK bytes of memory, LEDIP uses an effici¬
ent data structure to minimize the memory occupied by the
user’s text. LEDIP performs memory compressions and
expansions as needed after each line of text is entered. Not a
single byte of memory is wasted. In addition, LEDIP allows
the user to select the location in memory where the text
is stored. LEDIP’s small memory requirements make it ideal
for memory conscious users. With LEDIP, a reasonable a-
mount of text can be edited in a system with as small as 2K
bytes of memory.
Running LEDIP
LEDIP Version K4 (assembly listing shown), runs on KIM
systems with at least 1 .IK bytes of RAM starting at location
2000 hex and going upwards. Since LEDIP is a text editor and
not a memory editor (compare EDITHA/SWEETS, DDJ
Vol.3, Issue 5, May 78), and I/O device such as a teletype is
also needed. Readers with such a configuration may directly
key in the object code and enter LEDIP thru location 2000
hex using the G command. LEDIP should respond with the
question, “STARTING ADDRESS?”. This is the cold entry
point; warm entry point is at location 203C hex. Version K4
with the changes indicated in parenthesis will also run on TIM/
DEMON systems. Readers who don’t feel like keying in a
1.1K object code can obtain paper tape or KIM cassette of
LEDIP from the 6502 Program Exchange, 2920 Moana,
Reno, NV 89509. Include a $2.50 duplication/distribution
fee. Versions of LEDIP for other 6502-based systems includ¬
ing VIM (Synertek’s new 6502-based SBC) are also available
from The 6502 Program Exchange. JOLT users should note
that the TEXT command supplies the rub-outs required by
the JOLT resident assembler.
Using LEDIP
LEDIP starts by requesting a starting address for the text
from you. Type a four-digit hexadecimal location. Your text
will occupy this location and subsequent memory locations.
Be sure to specify usable RAM. LEDIP uses 18 contiguous
bytes near the top of page zero to store variables and constants
pertaining to the text being edited. In addition, LEDIP resides
in about IK bytes of memory. These locations should be re¬
served for LEDIP’s use and should not be used for any other
purpose. The FILE command can be used to find out what
these locations are. Once a valid starting address is given,
LEDIP does some initialization and responds with the prompt
character, a slash. A line number or command can now be typed.
A line number can be any four-digit decimal number bet¬
ween 0000 and 9999. Leading zeroes must be included. If a
line number is typed after the prompt character, LEDIP auto¬
matically goes into the edit mode, types a space, and waits for
a line of text to be entered. A line can be of any length bet¬
ween 1 and 252 characters. Any upper or lower case ASCII
character can be entered. Control codes and other special
codes can also be entered. All control codes, with the ex¬
ception of the backspace (control H), are stored as received.
A backspace deletes the last character entered. Carriage-
returns are not allowed within a line. A carriage-return term¬
inates a line. Text lines are modified, replaced, deleted, or
inserted using line numbers in a manner similar to BASIC.
Note that this technique makes edit-mode commands like
DELETE, REPLACE, INSERT, etc. unnecessary.
To add a line of text, type a new line number and then type
in the text. To insert a line of text between two existing lines
of text, type a line number between the two current line num¬
bers and then enter the text. For instance, to enter a line of
text between lines 0022 and 0029, type 0024 and then type
the new text. LEDIP will do the memory shifting and mani¬
pulations necessary, and will insert the new line between the
two current lines. To delete a line, type the line number and
a carriage-return. To replace or modify a line, type the line
number and then type the new text. To create a blank line,
type the line number, at least one space, and then type a car¬
riage-return.
If a command is typed after the prompt, LEDIP automati¬
cally goes into the command mode. LEDIP recognizes the
following five commands:
LIST — lists the entire text with line numbers
TEXT — lists the entire text without line numbers
FILE — states the block of memory currently occupied
by the text
EXIT — returns control to the system monitor program
(if present)
CLEAR — clears current workfile and requests location
for new text
The FILE command states three blocks of memory: a block
of 18 bytes used by LEDIP on zero page, a block of memory
occupied by LEDIP, and a block occupied by the user’s text.
The LIST and TEXT commands can be terminated at any time
by using the hardware interrupt or reset and re-entering
LEDIP through the warm start. LEDIP should always be
Page 4
386
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
entered through the warm start if the current text is to be
preserved. The EXIT command leaves the monitor program
counter pointing to the warm start; hence only a G need be
typed in most cases to re-enter LEDIP. An accidental CLEAR
initiation can be corrected by an interrupt and a jump to the
warm start.
LEDIP texts can be saved on tape in two formats for fu¬
ture use: an ASCII format and a hexadecimal format. To
save a text in ASCII format, type TEXT, start the paper tape
punch or cassette recorder, and then type a carriage return.
ASCII formatted type cannot be reloaded into LEDIP for
future editing. If future editing is desired, the text should
be saved in hexadecimal format. To save a text in hexadeci¬
mal format, type FILE. LEDIP will define three memory
blocks (e.g. 00D1-00E2, 2000-249D, 0100-01C4). Now type
EXIT to return to your system monitor program. The monitor
can now be used to save and reload the data contained in the
first and third memory blocks. When loading your text thus,
LEDIP should be entered through the warm start.
LEDIP checks the validity of commands, line numbers,
line lengths, and continually performs read-after-write verifi¬
cations. An error will result in one of the following error
messages:
M! nonexistent memory or memory overflow
C! invalid command or line number
H! improper hex number
L! line too long
In the case of invalid four-letter commands, LEDIP defaults
and executes the command whose first letter matches that of
the invalid command.
A Brief Look Inside LEDIP
In keeping with the objective of a memory-efficient text
editor program, LEDIP uses a sequential linear list (conti¬
guous memory block) of variable length records to store the
text. While a linked list or “table of line pointers” approach
would have resulted in less code, it was decided that memory
usage should be given priority over code reduction in the
kind of environment in which LEDIP is likely to be used.
The decision to use variable rather than fixed length records
is based on the same consideration. Zero page locations STAD
(starting address) always points to the top of the list and
LOCC (location counter) always points to the bottom of the
list. HEXBU (hexadecimal buffer) is invariably used to walk
through the list. Each record (line of text) consists of three
fields as shown in figure 1. LEDIP makes conservative use of
the stack (page one) and only uses 18 bytes on page zero.
These two pages are therefore largely available to the user.
increasing address
0
N1
N2
§
§
§
0
L — length of line (one byte)
N1 — line number low order byte
I\I2 — line number high order byte
CCCC ... — ASCII characters (variable length)
Figure 1: LEDIP data format.
Since the text list contains no absolute addresses or links,
LEDIP is essentially text-relocatable. In fact, the block
memory move subroutines in LEDIP can be used to move the
text around in memory. Only STAD and LOCC need be
changed whenever the text is relocated.
The other main consideration in writing LEDIP was to
write an easy-to-use text editor. To achieve this goal, three
decisions were made; viz. LEDIP shall be line oriented and
not string oriented, line numbers shall be used for all edit-
mode operations, non edit-mode commands and error mes¬
sages shall be kept to one easily remembered minimum. The
apparent simplicity with which line numbers are used to edit
text lines obscures the actual processes which go on inside
LEDIP during edit operations. The flowchart (figure 2) gives
a clearer picture of these operations and the routines which
are invoked by each. This flowchchart is roughly the second
level in a four level top-down flowchart development of
LEDIP.
LEDIP readily lends itself to modifications and extensions.
Readers who wish to implement additional commands will
find that the routines necessary for most additional commands
(edit and non-edit) are already in the program. It should be
noted that LEDIP does not use any command tables. Three
NOP’s have been included in the command handler (CMHD)
to facilitate this. These NOP’s will have to be replaced by an
appropriate jump to the code extension. For instance, imple¬
menting a single line or line number range LIST only requires
changing the contents of STAD and LOCC and then invoking
the already existing LIST routines. LEDIP features several
useful subroutines which are callable by other programs. These
subroutines include block memory moves, ASCII conversion,
hexadecimal and decimal character validation, save and restore
register, and other routines. Zero page locations defined at
the beginning of the program are used to pass parameters to
and from these subroutines.
Since the CRLF, SPACE, and type-a-byte subroutines are
as easily accessible as the standard read-a-character and type¬
a-character subroutines in most resident operating (monitor)
systems, LEDIP directly calls all five I/O subroutines. All
I/O calls flow thru a series of jumps near the end of LEDIP.
Hence only ten locations need be changed to implement
LEDIP on systems with different I/O configurations. LEDIP
saves and restores all registers during I/O calls. Readers writing
their I/O subroutines should remember to include proper delay
for the CRLF as may be required by the console device.
Readers who wish to add pagination to LEDIP listings should
note that one inch top and bottom margins on the standard
teletype requires 12 blank lines after every 54 text lines.
LEDIP does not feature a software BREAK test since
the hardware interrupt or reset can be used to terminate
LEDIP listings at any point. KIM users who wish to add
a break text would have to poll the 6530 PI A data register
at location 1740 hex. TIM users should poll location 6E02
hex. Since all I/O operations flow thru the restore register
(RESR) routine, a good place to insert the break test is at the
end of the RESR routine. Three NOP’s have been included to
facilitate this. In implementing a break test, care should be
taken to restore the stack and to restore registers destroyed
by the break routine. Since LEDIP preserves the syntax of
the input text lines, readers who are interested in language
translation will find LEDIP a useful basis for the development
of an interactive compiling or interpreting language translator.
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 5
387
3 “ “
u.i ac
H uj
vo K-
— z
O D
UJ O Z
O
v- a ui
of uj cr
-a ►-
a u >
u < a
a ol a
JL < |L
-J t-gr
UiOutc < a cor-sOir-vrmrsj —
ocoooc.eaoooooc
•»**»«f'«****’*‘*‘*‘*v**»**’
MHPNNHI'HNNNNNN
X -J
D D I _j I j a I jI Jl j
CKOQuua u ro o o w i/i
X X < ^ CJ o X UUJIU Z ZUJUJ
inujht-DOujl cd cd uj uj o o
I Ii^w j jK ui *- r ** *. •
* « #
*
It •»
* *
z
CJ
O
* • #
«
• «
“
Z
• •
•
f-
« *
*
vo
X
VO
« *
*
UJ
UJ
C>
» «
•
3
•
•
o
UJ
CJ
z
*
CJ
ac
QC
X
« *
*
UJ
UJ
►—
UJ
« *
*
X
>
UJ
K
VO
* #
*
H
UJ
X
a
O
UJ
*
o
X
LL
t-
“
CJ
►-
U-
ac
“
O
ft «
«
z
UJ
-J
UJ
<
«_)
VO
*
■<1
-J
at
Kl
X
vo
no
1 #
*
♦
CD
ft
M
U
»
UJ
vo
(X
mJ
X
►
• *
_j
«
•-*
CJ
Z
o ©
<
*
h-
U
ft •
U
•
«J
:*
CJ
ac
UJ
UJ
u.
*
f—
»-
a.
a.
X
at
» «
•
tn
UJ
O v
Z
>-
Q.
« t
UJ
♦
t_>
u
X
Z H
» *
Z
•
•»
-J
h-
« •
*
a
» »
*
o
z
* 1
3
»
Z
u
>-
• •
U
<*
UJ
* *
at
*
u
t
►—
* 1
a
vo
e-
<
« »
z
«
Ul
VO
v>
ac
i-
* *
•—•
•
ft-
a
to
UJ
UJ
• «
«J
«
O'
►
UJ
o
X
« *
>
*
»—
V-
a.
u.
u.
UJ o
<_>
«*
O
* «
*
CJ
-J
—j
UJ <J
>-
z o
• «
•
Ul
UJ
o
at
OL
U» »- 3
O
« «
•
Z
<
o
o
* vo O
f-
f-
f\J
• *
•
C
a.
a
•»
» •
«
—i
►—
o
o a
QC
a a
H
• •
•
O
3
z
J vo vo O O
vo z
•
•
* •
•
©
3
•—
CJ
->
—>
3 —J
-> “
CD
• «
»
a
»-
« •
•
a
at
* *
*
m
<
m*
« «
*
o
“
h-
c-
b-
« •
•
UJ
X
vo
<
* * *
*
* *
mJ
k-
t
*-
K
# * *
•
» *
vo
vo
-r
m
-r
no
(\j
<\j
rg
eg
fVJ
uj oj
n-
«#
•r
UJ QJ
m
u.
00 O
O C O' O oo o
O «NJ
rg
< CD
rg o
o
a
ac o
«* o
Ot H
< 4X
X VI
U K K
UJ l_>
— X UJ
to to
< UJ z
or uj
► O X
O VO <
U. h~ -
O — (
vo Z
uj < • :
c UJ
X -j
f ►— —<
ac <
UMU
O K
<t VO vo
to —■
to Q
It J I
X O 4 •
CJ » UJ
at o vo
□ uj «
* X • *
a >- o a
UJ Z UJ
0 3 1
• »- O H
vo u. o
ac o
UJ uj vo Q
UJ u u.
CJ •— U-
UJ > Z)
a uj co
Z uj —
“—JO
hOW
3 to <
O Z
at CD uj
O I
VO fr-
“ u
X X Z
O UJ
<* QC
ac •*
a a -
x — < z
ujOI -
X U' o
-J o
o o o
— o “ o
_J Z -j _J
o z o
UJ UJ “ <
a a h-
>- Z VO
»- <t
—J O
_j vo u Z
Z “
□ Z
O “
o 'T «J x XK 3 _j _j J X X
uo JC < u. O'^O-JXu.cdOOCDCjO
4IhJl»-MKl-<JX<UX<U
OOVOqc* Dl»D/>>aUJHDUJh' O
aIci(u»a*Ouuulviji^j
uai/>tt<tt<(xaaQC4t<44<<<
VOVOOVOOVOOVOr VO|/IDHkOhh
JO joooo Jinvuiflvi
Ohj'MJ'ou.O
OOOOOOO—
oooooooo
N(VJ NNN OJM (\J
- rjr> f in ^ k mao-M’if ir< .o r*. cu a- c «\j m r> uo r» a> O' q —
Nrgf\jpuC'j(\jwM(vjmrifnr'<fln(o«omr' < <r <j < <r >r <r 4 # in i/\ m o oinminoin^^)
iNjni^irtJSajac- 1
O n- © f\j E'J’tH'TOtDfvjOeDirujg <5
f* 1 © —« »r >riM\iircu40ocot)D
OOOOO'OO'Oooouoiriuoininin
rvjf\jconj<f\j<<\j^r\jru<cocD<oocu
rt in od < OU.N4N <QO<\j'T'Oao<
jjHMjj(vjMi\jnjnjmrrir'immn
ooooocooooooooooo
f\j eg rg r\j rororgrgn.rgrg»sjrgr\jrgf\jr\j
'•* m cuo'O-'njr'^K'-oNaiO'O
•r^r>-r~p^r-fu.toaoeDOD(caoBucooDcocz-
Page 6
388
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
X UJ
UJ OL
X x
a
*- X
UJ Cj
to cj
I UJ —
x z
Of —• UJ
1 J >
a. cj
K l
CO 00
I < a
uj i a
to cj z
>
a
3
X
3 X
CD
X UJ
Uj QC
x x
a.
h- x
uj u
*
3
Z
X — —
CJ
u
UJ QC
z o
— X
h- t)
3
O I/O
QC —
1/0
— 3
I <r
>- x
< CJ -J -J cj
O uj CJ
Z UJ
X Q-
QC LJ
z /
u —
CJ _J
►- -J X ►- CM C/ »-
I'll U I X _j I _j
Xft -*UN K UJuUJ ~
UJ 1 «jZ_jOOC.ZQC>I
Xo<-J<a«J— —
x a. r j j < x cj x
UJ* >t-UJ>> J|-
□ woaaoi'i
I J Jf X O X
uaoai'iQ.oau>-<<aaoaa;aa.
to t> uj to cj x uj co r ooj—uoooujc/o io i/i r
u. X
to u.
z —•
< o
QC U
J— X
z a
o uj
CJ oc
* * K «
*“ •> _J
-» -» -I 3
CJ CJ K —< *oj UJ it ji r< (j OD fo ^ m as H
CJ CJ CJ IO I O J «J X to _j X -o UX”>0”)»*|L<
U UONxd-QOJ- CJ Ch Z 0-0 0 CDujOQO»>H-
X CJ —j -J _j UJ X xZtoz_j—'XZxO_jIxXXOCDto
U> » — — OXo-J — :* -J X CJ — — -J-J-JX X J
< >- < a ujaaiuaaai'io.oaa.x^a.oviuaaa
z to to z to x to cj x uj to x o o x UJ cj cj to to *:
_jjtio<on“)(c*in*i«Diffi"»-ojjyeD
“> -> -o o
U. H Z
I/O Z —
z UJ «J
< QC
Of QC S
►— 3 uj
CJ z
to
— u u.
n □
-j
CJ X X
af h- H
k 0 15
z z z
O UJ uj
CJ _J -J
X *
4 -J
-J 3 45
u a, a cd cj
CJ X CD uo X IO JO
□ UJ l > > > H O
Cj j X uj CD CD CD to -a
x<u<aiaaouj
OOCDHt/OtOtOtOZ
J J 1/1 1/1 "O *1 1 1 CD
OOOOC cjUOcjOhitcOOOCOu
(NjiNju-rucc -r u_ r\j -*■ <JercDf\jf\ju_C'jr\.(\j.r
o- cj u. — >r oamuj-mrs x c u- *m in eo
< x « ajicecaiCDajC'UC/uuuuQOO
CC cjOOCJcjOOOcjOC ooc ooo
rj fc
CM cm
mno
INJ CM CM
.notuicoffo cd uj <\j fs. cj
rc < on uj o do cjo*co <
* o f*- m
r- o O' a <-#o>ocjcju..-. w^wu/wwi_»-r^»
CJ O CJ Cj ad x < c m ^ C < q^ujOqo OO*
u> O — —• OOOOOuOOuOOuNh^ o OC O O CJ
< 4 0*0 ONM ON ♦ NIC <r U. IVJ 4 44UU.O)ffMM-f
cDQu^f r i«r.0DcEOo# r 'Oajecoo< r '»C'r» (J ffi O u. N in
C/OOuj uj u- ui hi uj u. u. u_ u- u-u. OOOO O © O O —
O CjOOOOOC'OOOOOOO-i — r-« — —
i\ji\if\jfvjM(\jiNjn,njM(\jnj(vjnjfvjfijnjMnj n <nj n (\j (vj m
INJNNMN*'JI'J(\J('J
,r '' 4Jr '~ cd cr © — fM no -r m « n ai a Oo-fvjm^-uo^n.aj cro*-'«Nim^»n^r*-coO' 0 «- im c >r m z> co cr cj
^ — '• - " ,< «4"4^* , «*-*«x — «* — »4CMfMCM«MCMCMC\iCMCMCMfMCMCMCMCMCMCMCMCMCMCMCM ngcsjoor\jrvjrsjrof\j«\j
to u.
UJ •— P
> U X
- Q h X
uj uj Z CJ
Of CJ X ~
< UJ — LJ
Of » CJ
O UJ to
X * © X O
ha* - uj
to UJ > h- oc
h uj a or
Q CJ Q UJ UJ
Z x > u
x oc uj Z to
4 -J □ Z
u X u o <
CJ CJ to w QC
O Z t
_J J— CJ I
a u 4 uj
K X > to
4 □ UJ CJ *~
X QC X X
Ha *- to a
•— to x
CD UJ
a x to
3 uj
v to a.
QC to ►
H < h-
a Cj
a x
— to Ul QC
o — a 3
UJ to oc z
h a uj <
CJ UJ CD X
X h- X *
QC CJ 3 o
< X Z CJ
X a
CJ x UJ U-
X Z —
a
QC
CD
X _J X
CD X ►>
QC CJ CJ
uj a j a
h- UJ O Z
cj 9- oc -a
x 3 ►- T
Of Z z
< CJ o
X UJ CJ Z
CJ Of X
i- 1
UJ CJ CJ
a < uj
► UJ i
h Of O
io >r 3
cj u. u. cj to * o I cr
CJ J M ► < I CD I X X
M X a #0 CJ c j I > UJ .
« uc * CJ cx O x o cj I :
CJ CJ
CJ CJ
u
X
c-
o a ™ > x
_l Z UJ —J
x •_ x —
CJ CJ
CJ CJ
cj u x- x —
O x <3 or x a. ac of to a a x>-xq.oo- xv- < a uj u
-j OhtoOtotOtOCjX toOQh-I UJXOZHXZtO
CJ —J i/o —> —j •n-oaioijji/iuftoji-touoo ->
— *
-J X CD
—J UJ CJ
XI —
o
Ul
z
x uj uj cj
UJ Of UJ |
CJ h UJ Of
to Z Z UJ
< CD — U
CJ -J to
u z
CD CJ U X •
Z CJ Qf UJ
UJ X J to
zx~
— O h- to *
^ UJ O — Qf
a z uj
X ► UJ J X
I-lOh
i/i oc a
UJ to U H
> — — Z UJ
— a z
ujt hu-
UJ to Q; QC
UJ O UJ
Z X X H UJ
•—tOQfCJh-
h- to X X X
j Jaf-
X QC
_ ui x a
Of X CJ CD
to CD h- or
— Qf rc a
x Qf □ ui a.
»- uj ►— r. x
a r
h- CJ
CJ x
x a
Qf to
X *
X CJ
CJ X
CD
z
o
U
a
a a
X of
X UJ
CJ Kl
z X
CJ
h- UJ
UJ X
C9 CJ
—• *VJ X- —I -J
-X CJ CJ CJ C. iXh-CJCJC/CJ
CJ CO to CJ to (J 1/1 U to U. Cj— CJXOtOCJCJCJ to CJ “>
KOXCJ XCJ<CJX-J_lHf^'h-H-OXCJOLJ'rXCJ c.
uj ^ > I M > X > X > oc • 3tC3W|f*XjjJ>I f.x
0«au*QfoauQ'uiia«0J*au-»xa(j * -j
QcaujxQ-OCJUJcjujcx x a xq; q Q-O >■ xo. ujqx q. uj
toX Z Q* UJUJZZZtOQtOQtoX X UJOHX Z UJ o * z
—> CJ CD JCJCDOIE'-'(OOJ“IJO*1CJ(CJIOCJ(CCCJ CJ CO
IM h IM U. •rOUI^UJOOO*'I o- o - no ^ UJ
oo** - I'Jlf'f'OCUuOC'DCjOhO
& & * a
cj o u in
cr cd x r- cm m
'foooeuoujp
qd a m c> o fjccoocmc - — c o mcc - — oo
OXQjrVJ X NNMD4N4X(JQa.^4UirOUW
CJ o U — 'T 'OO'CJll.-i^MfiCCU.H'J^hO'OO
m m r, ^ -r>r>f44if'ifMrinu'inif'^ci'0i)«<!0
CJOCO cj cjcjccjoooooooooc OcjOO
fMCVJfuCM CM C\JCMCMfMCMfMIMfMC\ifMr\JfVJC\Jf'JCMf\jCMfvj
*r x- ^ o
CM CM CM CM
ocMcj'r—'TcjoxHOcroor- ■*'
x - xifoCM IM'IOOOQQUUO CJ no
ocrcni/o-oc-ooo (?Ol?OucrO'CHHOO , f' cro
M CJ O XCJU-CJOUJOCMXCMXCMXCJUXO-OOUX CJ O
Cioir>MJ(Dau.Hnna3<ou. NtfiMJCOiLtrJ inr~
r- h- h- Hr-Hr-HecaococoaDajajO'ao'O'ao-axx <x
ooo cooooooo oooooooooooco o o
fMCMCM CNJCMCMMCM<MCMfS| CMCMCMrMCMrMCMCMCMrMCMCMCM fM no
riCMm-cui^hcoag^ Mnxici'thfluO'O - KPwirtMuacJHMpi4in«MrffO"i CMmx-ir»u»h-ooO'Cj*xcMc»o*r»n"OHajco — Nm<nncihCb(Jo
OOOOOOOOOOCS OOOOOOOO — —I — — — — — iMNNfM(MNrjNMVJion(i.(OfOM(r. mmr>r4^^^4<h'r + ifMMfMniniiMfiir'ii'ii'0
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 7
389
< cj
►
U. < l
j. r. (\j _j
O n in
ui > > Ui
CD U O O
— X _l U p
Wl/iw Jl —•
Z ID UJ u > >
‘-DO ZOO
‘-ill -l l
<iaa <uui^u<Qiaa era
►■ninCJujirouj»-v»wv) it> X
i/nijwi/iirowT5*> —> —>
► - >■
3 UJ
o CJ
17) —j
— Cl
X co
uil D
2 a -a
»- cj ■
X O U.
u UJ —
— ox
n -I
3 <
er >
*-* — .
l/l UJ z
' <* X < '
z uj a uj
<► nn
-* Z ~
7-0 J
a « u a
3 a uj
o o x
ui* Zi¬
ff a < o
• i a
UJ < O h
■ O mu
C 4 UJ ff <
j — x >- »~
a ff- ff-i/o
—> u u
* < j: :
J o CJ
j * * i i
■ u< v u. u. Z ■
4 1/1 V)
I — —
—J o
u z
a <
►- x
Z X
U CJ
cj cj
o ff-
ff- U- X
a uj
x v- ff- ~
o o
WU40
K «/> ff-
— 17) 17)
4 ff UJ D
3 UJ I UJ
a. Z
o. i/i a a
Z O 3
o 4 a K
UJ ff * UJ
Jl-iu*
• </> —
) U. CO
-J X CO UJ o o o
— UJ — _j z z z
u. I- _J CJ <i «t •<
ff- _» cj «: x x
» » % « c a l
Ot-DhOKCJOQO
C/1 — CO*— l/^«—"1/1CJ CJ CJ
UI/1U.(^U.I/1U« -ft «
I*— U J H X J t /1 (j I
CO H - X * — •
O ft
a x
o ~
o x
o
~ ff- »
— i/o UJ
U UI o CJ
> co cnj m
z * r *
i a* oaoaoacjaoa.aaa.QL
J Z x UJ l LLl UJl UJ I uj CD O O X CO
J 4 CJ CD CJ CD CJ CC CJ CT CJ cc z Z Z O 1
O X z ff-
O CJ UJ 4
CJ »— CO ff-
-UJ * Irt
# o CJ CJ
4 4<<o a. * ff a
OXOIIXCOt/OX
-ja-jaa*o“»3-o
ix — x >- -j ►
Uj 4 o CJ cuu.occ c.cn
l/l UJ 4 h- _J _l «3 ff- «3
Qt^ft-3 -aKDO-3
u « u. □ u. U l/l D CO U
a>><oe>-a.a<Qe<a.
1/1 O O CO Z Z CO G CO C- CO
i j jo-iruo jo
OUl->rU)N(7'BDu.Mlfl a • CD
4 4 CD CD CD CD CD CD CO a CJ CJ CJ CJ
rvjrv.rvjrM<\j<sjevj(\jfsjf\jrsj(\j n n
(\ju-u> fia)«J4 — uui^ri
■J Cj *4 —
Cj 4 cm u
— rc M n
CJ CO GO CJ
Of ICO
v' cr cr Dora on ccr o 4 44uDOajaio®uOOu
4MUUUU.UUUUOUUJUJUJ4 INJ444«Cl#rM(SJ^
UlC«M ♦>0<U<UUJOIM4 «McauU-M<MH«(l CJU.
OOOOOOC-QO
IUU.ILUI
•MrjfM/vrvjfvj»Njf\jfvjr«je\jf\jf\j»\jfNjf\j r\j<\jrj<\jp\jf\j<\ifsj rg pm
ajir>r-«*oujc>< r| «f'oo<
OOOOOO — — -4 — —
rurvj«Mf\jf\jiNj<Mfv'»\jrsjr\.
fMIMf'J»\j»NJCsjfUfSjf\jlMfVJ
— fcim >riT.^jr^-ajCrO--iM ro>4»r 1 ,off-ajC2'0*~‘<\iff'W*r>>off-cuCT-CJ-«
i m pn r'cifiMpipicif''. (cnr'fn(ii(40('.pi(npiniT'mn(
immnnnrir po m m fn m <
inU)N0UO , O-‘MW4lf''ONCUO , t
ininirminoO'fl^-o .o *o -o mj «o ff-
i ffi fo m pi co co pi co co p pi p pi co co co
► O
15
z x
O QC
at uj
co —
O 3
UJ CD
22
0 4 0 XX
on
cj O o z uj ;
z < z uj o i
_i — X X 2
ff ff ff O 4 4 '
CO X CO J O J— (
OO 1 o _I n .
j a c X
_j a. cd
n a - i
O UJ -O UJ > > >
MDjDUOOi
j r <i i xx -
» cj cj o < t» oe oc :
1 CJ Z UJ ff- 1/1 co CO I
I CD •- ffl l/l 1 -> O .
• UQo
i J 4 O
ff CJ 1U
X CJ O CJ >Z)
uj CJ < CJ _J
ff- -J —I —J <
*3 X
ff- >
CO z
3 ~
cj co cj
I CD CJ UJ
I co CD o
CJ CJ
_J o
cj <
4 0 0 0 1
►- o Z UJ :
l/i C — en ■
-j a z
CJ QC —
cr 3 j
1 CJ ac 0 X 3 on i _i cj r 3 cr t—
: o a Pen co cr cj —> co i/i_j~>i «<a.o<
I CJ X > X UJ X UOUJOUJff— o> >>_jff-
: j uj CJ iu o uj O J 4 o jon 4 DUOon
’ — *- 1- X «. X •*- iX<X«j_jXXCOX
[ CJ < QC < 440 xo 0004 ff 0 ffffao 0
)BM/lQff-QjDOU ZUlff— COUJCOCOCOcoX
i co i/i o u i 7 i _j cj —j 4 uj — cn in -o cd ~o “o ~o ~o ~o
Z 17 )
— Z • CC
—J <3 Z IT X
— QC U ► >
ff- — cj a
ff- I- x x
QC CO QC
uj — uj ac er
co co co co
Z 3 Z -> ->
— o —
CC O CD
X UJ x
ui er u/
X » X
UJ
- UJ
z z
— o —
ro po pi p pi
CM (\J M N P: r\J
CJ CD CJ ♦MP 11 D 41 M 4 -* 4 «V.P-I
n «r po ooDDi/DMoaoff 1
(3 17 l\J 4
CJ Cj O CJ
O pvj
f\j a.
WU44P104
D D C O C d ff
OQ<7<DQUJ<MCJ
OOQCjujoOO
C 12 4 INJOHOr^NffCDO
D DO O UJ O -C C N o ^ UJ P’
oooicirnii'iffc^on'ooyooffi - _ _- - -
— <®<aC 7 UJU. 0 DffJNl\J 4 P '4 U <D O -< O IU 12 UJ Iff 4 ^
cr o uj
— ff cj o o
< 0-0 ffnru'O-oooo
oO^-moiniMrcoN—o ooiroovooco
pi 4 ffl 1C O M 4 (C«3 — «343C7UluaOf\JU-fNJC\jrofSj«r
UJ —« -4 ff 03 <3 OUJOM 4 4 j a' |D UI - PI 4 C (D < o Cl U H ff Iff ff <
NfO( 4 PipiPIPlP 4444444 IT« *r> l/> Ifl IT in int^in.cO'O-O'O
Po<MPvjf\jPc»Mf\j<\jporsj<\jf\jf\jM<MPoojfLjPsjrvjf\j rvro r\j rv ru i\j ro r.
C UJ o IM 4 ^J 12 CDQu. O M 4 ^ ® < o u — 4 ff 4 o
42-£ip-ff-ff*r^r-ff-ff*r^ajiu20Da.aia5CDcDCrc7'OO'C2'
— — — — -4— ^4 —
MWMffJNfVJIvjr'jPvjffjNNnjff.ffJivjffjffjpgnjffjfyjfNj
fj pm fsj cm rsj
-(\Jffi4KlCJff®C7C-Mffl4inilfftD(2V-l\Jfn4irajffO(20 -fyff1 '< , ' f 'O^ aj 0 , C3 - MP14in0N®C2C-(\Jffi4ll'iCffroC20-Mr'4lf'^ff®C2o
Pif0PiPlPiP)P)PlPI4444444"P4 4lC'ifitf'HlU'i/llfl|QUMf\^)'0'0'C'0'C'0'<)-0Off'ffiff-^^ffff.^ff.ff(Bloaj0D®BBOE®(2(2(2(2(ff(20‘(2(J'(2 - O
fsjPu^*r4rsjPuro«vjPuooruPur4PufvjiNjojPsjouPuruPuruf\jf\jroru«vjPvjru<>J«NJ^J^^J<NJ«vjiNiivj<vj^opvji\j04f^poPor4«Njr4r4c\jfNj»cf\jrurgiNjro<^PUP4roc\jr\ioocNjrL.p'um
Page 8
390
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
* N
» *
* c
0
it
•
•*
«
*
a
» *
*
*
UJ
* »
*
«
UJ
k-
k
# »
u
*
*
X
<
u
a
U
# *
UJ
*
•
k-
ui
-J
k
UJ
CD
* *
Cj
*
a
a
u.
a
•
k
►-
z
* t
uC
*
•
IX
o
CJ
UJ
k
k
CJ
* »
O
*
■#
3
•
3
3
cn
CD
UJ
* #
-*
*
UJ
a
cr
u
a
<j
•
X
k
k-
« *
-I
*
«
X
k
UJ
•—
X
X
O
UJ
a
►
<1
* *
■«»
♦
*
k-
Z k
X
k
k
cn
«
X
* *
CJ
*
*
UJ
CJ
k
IX
UJ
k
U
CJ
■* *
*
»
»
•u
-t
a
m
in
-J
• *
k
«
*
Q
Z
a
*
k
M
CD
UJ
CJ
• *
UJ
*
*
O
u
<
a
k-
O
X
• *
CO
#
«
*1
CJ
X
•
UJ
UJ CJ
LJ
k
o
a
*
a
UJ
• #
<
*
*
CJ
o
a
oc
u
u
UJ
< o
a
c
* #
*
*
UJ
UJ
«i
cn
—i
k • UJ
-j
»
UJ
* *
a
«
«
Z
X
>
a
k
in
in
X
<
cn cn >
UI
X
I
a
*
-j
#
«
CJ
UJ
u
ft
in
<
<
-j
k
3
x a
a
k
o
a
►
# *
<
*
*
K-
in X
UJ
t_»
3
CJ
3
O
U j uj
►
UJ
M
X
k-
* •
*
*
3
<4
cn
CJ
>
a
CD
O
UJ
k cj cn
in
X
• »
*
#
O
UJ
k
a
UJ
* •
i
«
u.
UJ
OC
o cn
OC
3
3 m a
* *
»
*
cc
I
k
a
< X
3
<o
* *
»
*
3
k
k- UJ
in
X
X
# *
#
*
cn
V
cn X
UJ
ui X k
* *
-j
#
*
a uj
w
►
X
X k
* *
3
*
«
_
k-
k
O
a
oc
□ o
* «
C)
*
•
i/i
<1
z
k O
k
l/'
k 03 Z
o
* N
U-
*•
•«
<i
X
in
ft
<1
<4
X
k
UJ <4
I
z
X
k-
* »
*
—>
UJ
i/i
k k
UJ
UJ
cn a
-j
3
X 3
<4
—
CJ
c
* U
in
•
«
CD
—
LJ
X
<
<
u
r-
uj in
in
a x
u
u
a
CD
CJ cc
k-
k-
* *
m
*
#
<
UJ
cc
k
m
CM
<o
in
UJ
k U-
3
-J
<
X
3
Ok
3
in
* J
Z
*
«
w
J
a,
•**
a.
k
O
-J
a
in »
UJ
k UJ
*
*
* «
—
»
-•
a
UJ
a
o
»
<
«•
«
3 k
a
U
3 k O
CJ
cj in
I
cn x
» *
K-
•
«
m
k-
CJ
UJ
CD
»».
-> Z UJ
UI
a
a
0 *
3
#
«t
k-
«J
► -
k
u
in i_j
in
cj in
X k
H
O
— ft-
a
U
<
<4
< <
X
O 1/1
i
* »
CJ
*
»
M
—i
<
o
3
CJ
a
k
cr k
UJ UJ
z
□ □ □
in
in o
k
-J
—>
* *
OC
•
*
CC
3
a
a
CJ
cd in
a
1/1 QC
X cn
<4
k a a
—>
“5
-j
in
-J c/i
a
UJ
* *
£E
#
•
r
a
3
k
ft.
k
• •
3
«
•—
CJ
ft
in
* 3
UJ
k k in
<
* *
tn
•
•
•—
cn
a
3 uj
U CD
cn
CJ
Z Q£ UI
a
* a
*
V-
•—
a
Cj
o
in
in
_! X
— k o
k
ft.
• »
*
»
in
X
a
CJ
<
a ui
X
*
o z
in
in
□
* «
l *
•
#
k-
<
•—
•—
CJ X
k
k
a ui <
X
X
CJ
„
« *
« <
*
„ .
,,
„
.a .
eo
« «t
cr
<i
. 14 .
« i*
•»
UJ
X
4 •*
in
14-
O
o
m k uj
z k
O UJ
U «/l
Q- O
W a
CJ UJ
CJ pu
UJ •
z c/
— CJ
k CJ
3 -J
o
(X LJ
ec Z
3 <
in
3
c/i 0D
— X
X UJ
►— x
UJ
in
* o
QC UJ
UJ >
x a-
k UJ
O cn
UJ
1/1 «
— Q.
UJ 1/1
UJ
UJ (J
oc
<4 «t
UJ
k
ft-
CD
(X
UJ
CJ
QC
CJ
UJ
a
CJ
t_>
a
UJ
o
QC
CJ
X
o
X
_i — T
3 -J -j 3 x
(C U I B U
X <_> a x CJ
UJ O X u CJ
X _j cj I _i
a uj < a c/i
D * Z O ftT k
JUCC JUft
oc
• «t
a uj h
UJ CJ Cl 1/1
X <4
k ■< in JL
m a
L 1 /UU 4
a ~ ft *
K
UK tt UJ
— a x
« Of »—
UJ U cl
k - UJ □
CJ k
< UJ «
oc uj k- Cj •
< in CJ uj o
-> X Z z UJ
X CJ U oc >
UJ k u- j at
*/> < ► UJ
oc tn uj 1/1
cj c/> * • QC ui
— UJ U U QC
> uj uj j a
uj — x a u
<n ujo x oc ►
x CJ O I-
uj uj o uj Z O
to QC Z OX
< C/1«J <
Z. UJ —
QC Z UI c. >
3 — CJ U Z
ft" k ~ -I < *
UJ 3 > QC o
Oc CD UJ cj CJ UI
I OC O uj k
uj cd «* a o
O 3 Ui k QC
< Iflj *kk
— o a 1/1
a c/> c/i c/i c/i uj
QC — Z — O
X O u
CJ k- O — CJ -*
z
OL
3
k
a uj
uj oc
k l
O UJ
«J CO
QC X
I QC
CJ OC
UI CJ
CJ
UJ 1/1
QC —
X Z
CJ CJ UJ
k C- <n
UJ V* OC
O » CJ
oc a o
CO * UJ
1 u cc
CO
QC
CJ
'T e
M fc
a o o
< N «f
tr o cr o cr o
CJ CD UJ O UI -o
O O Kim IT lf> o
(VI M < 03 < a) «
in «iO«i mo
< UQ< U4J
o a o
<m 0 u
C UJ H
00 CO O'
<\J (NJ l\
ro f\j cm
•T eco
ir a cj- a ao
ru cm cm re fsj r\j
M MM M MM
UJ - ^ CO «J (j
a- «j < -a *t < «i
M MM M M M M
M MM M M M M
Q U_ —• rr iTv k~
< 4 a CO B) CO
M MM M MM
fM MMM MM
CO CC Q
CO c cr
f\J f\J fSJ
CM CM CM
-> m r -r in .£> p-
•r >r ♦ «r ♦ ♦ <r
^ *r ♦ 4
!C O u "* M f
^ <r ui inir in
♦ -r * *■'*■>»
^ IQ i) N OO O
IQ |Q IQ IQ IQ |Q
-r -r ^
Cj »h M m ^ tQ
•o •£) •&>•£> *0 4:
■* -ft «r *r «r
•AJ fM O) a Or-
O vO k k
>r «r <r < ^
M O) -f |Q i) M
r» k r<- k r-
•r -r «r ♦ >r ♦
ajoo-Mn<iQ^Na)Ou-"Mr
kMDCDOJCDcoaiajocDmoooO'
>riQOkWO‘OHM
000000000
M*IQ^)kCDOO
OOOOOOO —
IQIQIQIQIQIQIQQ
X
3
U
X X >- _l k k
CJ CJ CD CJ CO <3
I k CJ k CJ k k
- 3 □ 3 O 3 IO
QC Ui <
Cj CO _J
UJ 3
Z □
— I
UJ c /1 J h- U- < l/l li. u I k
COX UX-Jk«Jk kCJX
a J I uiac</>a«A3Xui
UUUkU JO* O-k
U- oc a uj qc a. ac < ac at a.
COCOCOZcoX in O in in ft
oc cc
U X
U. UJ
t < -4
k
a. a
► ►
► k
3 k- 3 k
ID V CD >■ UJ CJ CD H
X CD X CC cj CO X k-
UJk- UJ k < <X 0 CO
ft UJ t CJ Ml 3 X 3 UQ.Z —
O 2 UUI «»0 • U WO « j
acaacok<cLk<oCQcaQca
lOCOCOUJQOCOUJOCOIOlOloX
TIICEJJ-IOJITI’II
Z k _J
UJ CO X O
to X a. ft
3 c/> -
CJ z t
QC o C
CJ
*• I
QC UI C
k- X *
z k- :
UJ CJ I —
J k-
a * uj
— ft o _i
k s k ~
— X o u
X X k
U Cj >—* CJ <1
-I Xk- CM k k
QC • 3 ¥* 3 CO
U * G * CJ J
<*ja<Q'<oca.
—1 _J to o c/1 o 10 x
1 Z <1 —
UJ Z
O 0
< CJ
oc co
CJ z
QC <
ac OC
CO CJ
UI z*
Q. «*
-I O k
a - 3
Cj » 3
10 C/> QC
— z <
IGk
k- CJ 10
-r -r «» o
CM CM CM C\J
CM CM CM
MMM
>r o CM
CM CM CM
cn cm
CM CM CM
CM CM CM
CM CM CM
>f *r «r cm co c\j
CM C\J CM CM CM CM
*♦ ■+ < O -C *
CM CM CM CM CM CM
Q -f < >0 O OCJ
CM ir> CJ X) CJ CO
bui UOM U <CU- « UIQ
cc cr < cj «r u- k iq mm
-r o co cm o <0
<J < (J O G) <t)
o O ^ U -f
O'CIQU. CM in
M Q -c - C U CM CO ■f’
^ IQ M IQ Cli <» -f IQ
O O IQ O IQ C O
< CM < CM < CM «C
oooooojoo-ooo
MMMOM-CM<MM'C
o 0000 — Oao — OOO O c_>
CM CM CM U CC CM CC CD CM CM <M CM «*■
BCDOOOOOU 00-0
4JOM«tM<M-t M < M
O U CM >*■ k O OJ
—> ^-1 M CM CM M CM
CM CM CM CM CM CM CM
CM CM CM CM CM CM CM
it cm iq od < o 0 co in cd cc
CMCOfOCOCC'CO^^ 'C
CMCMIMCMCMCMCMCMCMCMCM
CM CM CMCMCMCMCMCVJCMCMCM
UJ-.CkO'BOO-BiJffuLI.
♦ IQiQiniQlQlQ^J^^^^ X) •£
CM CM CM CM CM CM CM CM CM CM CM CM CM CM
CM CM CM CM M CNJ M MM CM CM C\J CM CM
Mn^kauiu-
kkkk-kk-ka>
cmcmcmcmcmcmcmcm
CMCMfMCMCMCMCMCM
CMT
an 01 co
CM CM CM
CM CM CM
— CM
k* r»
CO CO
if m 4 J
k- £ £
k 03 O'
k>
cn n fc,
CJ — CM
CD 00 00
cn cn cn
m u>
00 co 00
•C k (D O' O
QD 00 CO CD O'
cn cn cn cn cn
— cm cn in
O' o O O O'
cn co m co co
Ok 03 o-o —
OlMkOOC
(ci cn cn co >r -c
CMCO'T IQ -O k OD O' O — kJ
ooooooco — — —
cn-cmokooO'O* - cm pi -r iq 4 k cd o- u ■* cm pi >r iq
— H»i»<^«CrMMriiNCMCMCMCMM(MCMC*lP1(nmfnr,
^ >r >r >r >r
<ikojoo
co cn co cn
-f ♦ -» «r 'K
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 9
391
Ui tu fr-
oj a z
CO < UJ
O — •
*— ae to
uj at
to U. UJ
Jtf u fr-
o 3u
uj cd <
X o'
o — <
*- x
u-' cj uj
Z CO
ae •—
O u. x
u. — a
- » o
a <
ft UJ t/l
—j —
► UJ
OC O
► CO <
Z •- _l
UJ u.
O I
• < t_>
-4 _J
it u. •
X | o
uj cj z
3 C
0 3 —
ae ar uj
cu UJ UJ
3 to CD
to <t
at
V U. u
ar O
fr- -i
Z to <
UJ fr- *
Z —
UJ UJ u .
_J »- UJ
a z o
— o -«
fr— UJ X I
H Q fr- *- _j
to < u_
— V
X CO
k o —
t_» o
UJ ae
I CO UJ
U-* cc xr^it— X<*Ox x
u uj <_> X'TI-TXrnirox uj
X C. ^^DtiV‘Ut»U(J*U^U x
*0»*<«Q«UJ*UJ%UjI»UJ o
► a ►x<^OB.trta.(/)^(/)M/H)(oxiu(/t
O * O O Q O UJ * UJ » t_> » UlUJhUJZU
j u hmj a uff uaucr uao ea
• z —
j—o»h-
i a uj z uj «
■ a o — to <
*r — oj
^ i x
u 3 •
C_J 3 a: O
CD X UJ
CO x UJ >
f~ Uj I QC
Z X UJ
UJ Z CO
— UJ
z <o ae
O a a
uj O UJ
x o z «
»- uj < o
fr- UJ
co Z UJ ae
O X <
UQH uj
< a. _j
co o
C- K h •>
O UJ UJ
a U o ►
CD -J Z O
3 «* ar
CO >- fr-
ar 3 co
co O co UJ
— Il x o
X uj uj
fr- T- X <
O CC
Z X
fr- u
< ~
o
< ae
a o
u ae
ac ae
a. uj
_j _i -< x cv
3 3 ® 3 UJ
cc CD X cc _j
x x uj x o
uj uj z uj z
X x — x —
QU O
z uj _J
— o
-1 c.
at — ►-
o
<
a
o
fr- o >- o is
UJ CO z Z I
UJ — —
X<UJ<J<UJUJOC0
OOjCkUZujh
—i— juj<coco — cd at
3 < (
o o
ae O t
—J J U i. u »
U U> J U J I
U tJ U tJ CJ >
o o z o z z
x<t_jc_><ujt_»ujato
oo-io^-ozz*-*-
_J _J UJ < CO CD — CD -5 O'
u uj o uj o to < < >r o m »r>
uocjooocj>ro<c;r , cjc , 'CJ uj
oooootooocroo'oaocT'O if o < oo
< >r <<0(ju.uautcutroff —-o uj~o o
ro'uuJu^-J'CaxuiuyN^CMCOtt
OOCOrJ«rt-^r‘^-MNM(MMM CM f\J
mcnmcnrornr-rocomr- n (o m cn (o co co con
f\jrjf\jf\jf\jr\jc\jf\jc\jf'jf\. f\jr\jf\jf\jrjr\jf\j cm fM
o ujo«- n ion a cc
Mrofomitimcopir
focoforopnr-rorofo
f\J CM csj cvj cm cm cm cm im
uuJo^r'iof'CMiuj
m c. 4 # ^ ^ -j- >f ^ ♦
co m n co jr, n r< w n
\ o r» oo cfr O cm cd < tr* -v
•-- - r «# «e *e
)>o -o-o «
• ae
ae uj
< < a. at co
J Jl tflh
ft u oo a
► >
z —
o 3
— X
uj uj
CO x
3 fr¬
ee co
X U
uj o
X
ac fr-
UJ
CO x
3 -
O UJ '
ix to I
CO CO
— UJ I
I CO
fr- <
UJ <
fr
u> to
X X < <
uj uj at —
O O < CD
Z Z I
— — o x
fr- fr- » o’
uj uj uj a
to to o <
3 to
cc <
<w> —
C\j < to CD
: *t < < < <X < fr- << fr- X UJ
i»- x<a. _j_j_j_j<x<oruJUJ< x >- uj co
OCOtOIOCOtOtOfr- LU O to _J Q fr- UJUlZfr—
-j _j _j -o < < <1 < wo JO u <ioq otfa
X o
or z
K Z
— 3
CD
ae uj
a
i z
uj CJ
cd Uj •
3 u> c_> o
co o c_> Z
-j a <
UJ _J
z x X
— o z
»- at — %
3 U O
co ae » CD
3 uj to ae
— O UJ
I ui X
uj fr-
o CJ
a <
fr- ®
uj 3
O to
-J tx —< — i
(JftUUU
o r u j (j
OujUuD
_J fr- -J O _i
Uj < UJ < to UJ CO
UJOCDfr-OUJfr—
co j co co cc o at
co
< i
C_>
Cl
U. _J
o ®
o <
X — UJ
fr-Z flt J
— uj uj
co u.
UJ o LL X
a Hi D
fr Z (L •>
fr- — o
<XUJ
<- fr UJ
3 3 to
CJ to CD UI
at at x CD
CD UJ UJ
3 fr- X ►
to UJ
< V CJ
to ae cn 2
— < <
X X O
fr- UJ fr- <
X CJ
Cl
K
X < z
UJ at u
o < fr- ae —
z i — o
to o fr- CO <_>
X UJ X CO u.
UJ fr- UJ < -J
n X 3 o x a a
** — a * - a u
fr-<atfr-<xaujaco
OCcoXfr-OX Zcofr-
-I -IO - h JU co -> ue
CJ CJ
to to
< <
a- a
D c
o r
< —
X CJ
UI UJ
x o
tr oo tJ“ dj <*
o o o o a
OMif'C«<<j<ir<inOajir'0'<(nCu
< <cD<veJOOCJOoujeD<\J**'00 , tjaoau;
ft. 0--r fr
CD CJ CJ O CJ
cm fu rsj cm ro
CM f\J CM CM CM
cu <ouj— fMcn>j-ir\fr' od«x q ujo ^ ^ir»K
UUUUaOODDOCD o o iu UJ UJ Uj ui
CSJ<MtMr\J«MtMfM«MCUCM fMfrofSjCMf\Jf\JCM*M«M
(Njr\J«MfNJfMf\JrofMfVJfMfMCUr\.rvJ(MCMf\JtMfM
CD a CD o U_ — fD
uj uj Uj uj uj u. u
M f\J CM CM CM <M CM
f\J CM fVJ fVJ CM fM CM
»r so oo co uj Cj u. — f' -
uuu-uuuuoCO
CM CM CM CM (M (M CM (O (r. CO
M M M M M M IM OJfMCM
h t\j rn ^ uo^ofr- coCfro •-*<Mr'rtr>>D'r~. ao- o — CM r ■•■^•cfr-aJtro , - , fMr-'-rcr«ofr-cDCruJ- - <MP r i<'tr'-or^oJO-C5--CMri^-ir'U)fr*cua'0'^rMf»i>#-uo^3fr“aja
irvir<ir>ir\ir>tnir>inu>io 1
Page 10
392
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
o
UUJO V)
ZZUJh-
Mfiec (i
o co i/> af at _j jpi x _j
•f uj uj u.i » o u a a wa w i
UJOOI’IC z Z > z lli uj » uj :
l r * x _i u z uj^uiOuj c. *-< o o o t
« - . v < i. iu |l • i i i » * i » i ;
v <<auiaou<o<wuu<u<wui
o o ►— S Zi/iiuujoir»-uujuiOa:»>uuji
J-xx-j-j CJ — X —
UOUUO u M O M
yujzuiu o > z >
Ob ujDcd O-iOUJO
J( UK •« E t 1
JWW JlrtO J*
• — M
I *- MQ
> > Z
) Z — C_J UJ
— » X E
j < < a. c/ <_> to <_>
’ j J X UJ CD U 111
} a. a. n i/i to ff d
CO IT\ f*» O'
cr- a- cr tr¬
ee co co co
co co co co
O i*’ «*•< OU o O' •-« ro r\j >r ■« h ■* u. m cd
c o u a cj o cjocco o oqcjcjg
C h — p- C (J O ® u' U 1C C OCDicau , 'OOCO
<auroONu.f><uiaJBu(n<ujV8iui7'<
<UUJO* v '<M? < u uj c m ^ ia c ic o u. »<
Craff<<i<<<<<<QjirttcEa a: cr c « u
fncomfc mmpifnP'(rii , 'ncifnc'i*immfnnir 1
r> cororv cof\jf\jcocof\jcoco cococo cj cj m r. cocj
^ O < y in O y O' < IC Cvi — co-r
OOOOO (90000 ^ o o o
(Cu>icmicc0fvj«<O ooo)®oiraoj3
<CDCD<cw<cy uj o -o ^ ^ m uj cd u
ffffOu-Hen^^cD 4 uuju.C^^£(d
OOOOOOQOOOOOOLUUJUJUJUJ
rofooio'ifocoroccfo cneoeocnfococnroro
COCOCOCOCJCOCOCJCJ CJCoCOCOCOCOCJCoCO
c ® a o —< co c •ric^K-ajyc.-c-ci'Ctf'XJcioyoHMp -r IC XJ t- <u ff tf - w rw
-*•■**■' cococo cocococococjco ro co m rc ft -r o ^ « tc ic ic ic ic
to >o r- oo o 0'-»cofn'Tu>^)f^ooo-o-«cjrr, ^ tc .o r- wo'0 ,, "* r ' J<T), ** f ''0
lCiClCiAiA<O<O4)^)4}<O>O^4)4}f>>NSNNC-^h-f k -NID <D C0 < U(DC0(n
c~r^r-c*r^r^c-r^c-r^r*r>-h.r^r-f*.r^C'f^r>r»r^r»r“^-r^r^Nr'C*r^r>-
» •— uj m
Z — •
I O •- Q
Z _J H- UJ
D — >
I U at at
u UJ I/O UJ
i X to
i on O uj
a
• I u a.
< 3
U DO CO ►
•“• — 1 X
h- UJ O
Z O X Z
UJ <1 <
O _J z
— u — -t
_J 3 — CO
u a> jt y
O X X X
CJ UJ o o
CM J X Z Z
>- < u cj o «/> v <a w
OOF u uj h uj o » ►—
jjOBBaojua
< a o (f>-
O J uj ►- I
j ub a .
-J -J O i x
O O F o O
Z UJ o Z UJ
UJ CD Z UJ CO
IKUJIX
< a uj < a (a
OF Z O F h-
jub jua
) < X o
z o
■ — —• I/O
• K X uj •
J w O O
UJ Cj F UJ
J O H- >
O a
► WZ Ul
j a w
: o uj uj
■ i at o a
uj o uj U-
) I Ol
— < F X
o «o to •*:* j c x j -j
UJ UJ UJ E.UJFOE O I/O x
acoo—<» X O uj > uj uj >
OFF F _JZ u Z B CJ B D □
XujFFFFF
► <<uoaaouujuu'u
O Q »- I UJ X CO uj Z Z Z z z
JJl/)UBOOtL«CC->-.CC
m y O m •* o* o
OOOoO o o
C-^COOBr'-u
<Bomi«aiBQ£
( r )lA-/p-f r lMuO‘ACO^jH'lJ
O D U C) O > >0 w* CJ O O O UJ
O - - - C U O O X) o x> >o o
< en O' o u. ■*■ co u. uj o uj uj o
u. -* ci in h- y «x b u u.
^u>if'i/>iAicir'UAicir>
fr m m fn m n n (n in m
co cj co cj r\J cj Co co co cj
O Co >E -O h» O' 00
>0 -O -O >C -O O -£>
CO CO fr\ pn (T CI CD
CJ fv CO Co CO CJ CJ
UUI O M •T O
»o .o r- h- r- c-
C1 CO to fO CO fr)
CO CJ <C Co CO CO
haBOitH-rMTicQuc
r-r^c-r^r-cocoaju/oooaooo'
COfOCOCnCOCOfOCOCOfOCOCTiCO
COCJCOCoCJCJCjCOCOCOCOCOCO
f^ajOC'^c^c^>ru^4JC-(ijoo^c^ro^iCvor^auO'Or-cocn>ric<)r-cuO'0^‘Cjco>ru>^)r-CDO'X:»-coco^-if>'Or-ooO'C^«--*cofO'T»f'^5f^auoo-<coco>riC'0
■jccif'iriAifiiAir'iAif'ir'iA^i'O^iic^^^^'O^c^.f'^-ccsfW'C^BoajeocDffioBBoyyytj'yyyyo'O'O'JOOPOOOoo - — «'•*
'0'0'0'0'G'B'0'0'G'*J'0'0-li'0-G’CO'V'0'G-0'D'0-0^'iJ'0-0'{)-0-0'0'0'0'G'0&'0-0'0-0*)'0'0'0^'0'0-G'00-0'GT* , T*"t^T*‘T*-t , ~l*-T*‘T*‘1‘*T*-f , -r^1 , + T^T , *r-
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 11
o
ID
♦ * *
• * #
V- Qt K £* Q t
U l_) O (_) l-J
<1 u. «a U- ui u.
(t a u
< O' < •£> <i h
x uj x o a h-
U N U W 1/1 m
^ r*- r-
<* m < v-
►- — '
ah- >- co
t/> m tr rv
O Uj Ul (D
«t i/i at/i
u 3 ► 3
aw t— —
LD UJ ID UJ |
a t/i a i/i i
>-3 v 3 i
< x >- co
* h- h-
i/i t/i c > O'
a n a a u\ a a «5aacraocnooi/i
>Oii/i>ujc/i>uji/i>uj(/i> uj uj 2 uj
<1 —« ID <1 — iun — CCUJO
aaaaaaucaaaaaaa-flxv- a a a. t/>
l/l ui I l/l } t/1 l/i X tfl ui X t/i l/1 o Q O CD O O h-
ttCJU. -
m m m •$■
*r ^ -r >r
eg f\i f\i r\j
ecu. uiroucDouffluiuiEiDinr —•
m f\j uj r. in o r < ^jpiaujricicjou
OOoOOoOCoOOoOOm®-*- < < < c
4 LD ID UJ o
MH4)cuJH>f^<c)0(f l ujauujc inj jtw in
'h'h •*>*>» inintnmm>o®*J-0*0'*)h- h-h-h*h-
'T-T <r 4 « <r ^ ^ ^ ^
Nf\JI\MV|MMfVJM(\!(\JMr M MMfSJ fVJ (\| N IM (\J
f f '^g , iu0'th | f f >u.0^Q0C)0 < iCN0Q'h
ir«fui^M^iMjimi«^iNjfnoo © o m m fg m
'0«)<uuJOM'»oa)<uui"iMP, 'nrhO'io
hhhhhCDflOOJCDOOff iDCOaa'O-O'O'O'CyO'
•r ^ 4 ♦ ♦ -I ^ -e <r « ^ 4
rurgrorgfgfSjrgrgfvjrvjrMrgrgrgrgfsjrorgrsjiNjfV
a; cr O — m m m.cr-coo«o^rNjcgf\jf\jrjrgfvjr\jrgmmmm>r.e -e *■ in m m m ®
©«©©©©© ®©®u)(u©a)©uj(D©aj©aj©®uj©iucoco ®®®®®®®®®®cD®®®®®®®®®®a>®®®®<r>cu®
‘ -L -l X .
> O — O o <
Ul —* Uj CJ .
) CD J CT □ |
*- < » _i 3
I MXJ
- moo
• >22
I mt O UJ UI
I * l * W
O © CO <_> ■< l
I UJ CD U UJ h I
I 1/1 1/1 (D Q t /1 C
UJ <1 <x .
X C> <
-J CO .
nj o
♦ ♦ > ©
o a
o o o X -J
O O ©
a o o a <
_J _J _l CO o
X uon i -j
co o © m co •- co
UJ O U > LLi — UJ
O O CJ _j CD O _j O
i « -J w t X <L
**x©<©©©o<co
i-D j oau z uj c- h-
ui _mj «,i<icd—• ® t/> a.
X QC < X UJ
Ol/ll- UJ Z
jOI/lQfll
® uj o mm
«i r > >
o a
> •• •* •••*»-*
cd >0 CJ 004 o Nr < hir m ru ^ m
OOCJ ooc oucjooo o o o o
S 5 C) c
Ou-w-m>» - ®®<xt_jujonj'*'«Oh-<2®Ou.
UJ UJ u u. u. U- u u u. u OOOoOOCOO
mmmr
rMruMtvjMiNjMMMNMrurvjcjrcMNMivj
(TijUJCnjminr^crccou
X«*J —ifgrgcvjfsjcv. pg eg eg rg
^ i\ifvjfvjf\jfvj«\jcgf\jf\jf\j
© f\j in h- ®
m m m m m
*f -r -e -c
rj ro fu Mm
h©0'C-Nfn-etfi<jh©ao- < »'j»0'«’©oN©0'OHNn^©^)r.Eao-<M»o^jfioMD(j.Q^fy< , ’’rif'< ) h®0'0- < M* , '’Cif'^hB0'C‘P<N©g’ino
® <d co a- ^tf'ffaao‘»atf'ooooot>oooo-»i^H*i»i»j^Huwhj(\jNMN(\jNfyjN©j*im' , 'i r i f| ' , '* , 'h©'C'» ■+ '©<#•** * -e •rmmmmmmm
h-r^h-h-r^^h-h-r-h^h-h-r*®®®®®®®®®®®®®®®®®®®®®®®®®®®®®®®®®®® 50 ® 00 ®®®®®®®®®®®®®®®®®®®
Page 12
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
QUICK AND DIRTY FUNCTIONS
FOR BASIC
BY DENNIS ALLISON
169 Spruce Ave.
Menlo Park, CA 94025
Recently, Gene Wallis called my attention to the fact that a
number of BASIC interpreters for the hobbyist are not provid¬
ed with a full complement of intrinsic functions. He was work¬
ing on an energy utilization program and needed sine/cosine,
log, and power functions badly. These programs are quick and
dirty implementations which I did to give him a tool to get his
job done.
A word of warning though. These are quick and dirty in the
sense that they have not been carefully tuned or tested. They
may well contain errors. Certainly the choice of approxima¬
tion may not be optimal. All the functions are computed by
using various range reducing formulae and then applying a
polynomial or rational approximation from Hart’s Computer
Approximations (Wiley, 1968), an encyclopedic compendium
of approximations which is now out of print. The approxima¬
tions given in the algorithm section are all accurate to better
than seven digits, but the programs should be trusted to only
six digits or so because of truncation of the coefficients,
carelessness of implementation, and the vagaries of local float¬
ing point arithmetic.
The programs are also given in BASIC. They have been
tested using the dialect of BASIC supported by the Unix time¬
sharing system. The Unix BASIC differs substantially from
most hobby BASICS, so the test programs were transliterated
into something more generally acceptable. Beware—errors may
have crept into the code.
Lastly, if you do use the programs, considerable efficiency
can be gained by tuning the code to your particular BASIC.
In writing the functions we chose the simplest possible code
rather than the most efficient. A little rewriting may speed
the functions enormously. All these functions are to be
invoked via gosubs; they expect an argument in x and return
a value iny. xO,xl, x2 ,... are used as temporaries.
Square Root —SQR(x)
1. x < 0 is an error
2. reduce range
t= 1
jx =x/100; t = t * 10 | untilx<l
note: x * t * t = original number
0<x< 1
3. make a guess at Jx via a polynomial (accuracy is
.56 digits):
y 0 =.115442 + 1.15442 * x
4. iterate until ly n + 1 — y n \ < 10~ 6 (or so —depends
upon floating point accuracy) using:
5. final answer is:
J'n + i * {
You don’t really have to do the test in 4. as the iteration will
double the accuracy (approx) every time. So:
iteration
0
1
2
3
should be enough -> 4
certainly enough -> 5
accuracy (digits)
0.5
1
2
4
8
16
500
rein
y =
sqrt
(x)
510
if
x<0 then
goto <error>
520
xl
= 1
55e
if
X <=1
the
n goto 570
540
x =
X/100
550
xl
= xl
* 10
550
got
o 530
570
y =
.115
442
+ 1.15442*x
580
x2
= 5
590
y =
e.5*
(y + (
x/y ) )
600
x2
= x2
- l
eie
if
x2>e
then
goto 590
62e
y =
y*x 1
ezz
ret
urn
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 13
395
Log Base 10
1. x < 0 is an error 1
2. x < 1 then j sign = — 1 x = —telse sign = 1
' x
3. reduce range, find n such that
since log (-^) = — log(x)
— <— < 1
10 io« 1
and SCt * =
4. s=/l0 x
5. z = (s — 1) / (s + 1)
P(z 2 )
G(z 2 )
6. lgt =
(n + r —
.5) * sign
^0
3.1878
22082
024
Px
-2.6558
08794
66
P2
.26686
32700
47
Qo
3.6701
15625
115
Q i
-4.2809
73292
83
Q2
1.0
rem y = log(x) base 10
x <= 0 then goto <error>
= 1
x < 1 then xl = -1
x < 1 then x = 1/x
e
< 1 then goto 600
x = x/10
5e0 x2 = x2 + 1
590 goto 660
x = 3.162278*x
x = (x -»1) / (x—1)
y = x*x
x3=3 .187822+y*(-2.655809+y*0.2668633)
640 x4=3.670116+y*(-4.280973+y)
650 y = (x2 + x*x3/x4 -.S)*xl
660 return
500
510 If
520 xl
530 If
540 if
550 x2
560 If
570
600
eie
620
630
Power lO*
1. alarms if x too large positively
return zero if large negatively
2. if x < 0 | inv = true , x = I x I }
e l se | j nv = false |
reduce range to [ 0, x /i\
n = int (x)
x = x — n - .5
_ 2x P(x 2 )
Z Q(x 2 )-xP(x 2 )
result = /TO 10 w (z + l)
if (inv) => result = 1 / result
P 0 69.5569663167251
P t 8.7517567967368
Q 0 60.4164133787158
Qi 34.2951432306918
Qi 1
5e0
rem
y
=
10'x
510
xl
0
520
if
j
< 0
then xl =
1
530
if
X
< 0
then x = -
X
540
x2
=
int
(x)
550
x =
X
-
n - .5
560
y =
X
*
X
570
x3
=
es.
55697-*y*8.751758
5e0
x4
=
60.
41641+y*(34
.29514+y)
5S0
y =
(
2*y
*x2 )/(x4-y*
x3)
600
if
i2
=
0 then goto
640
610
y =
y
*
10
620
i2
*
x2
- 1
630
got
0
eee
640
if
xl
=
1 then y =
i/y
650
retur
n
Page 14
396
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
Inverse Trig
1. If x < 0 return —atan(lx l)
since atan ( —x ) = — atan(x)
2. If x > 1 return ~ - atanf—)
2 x ’
n 1
since atan (I x I) = — — atan (yjy) and x > 0
3. compute atan (x) in [0, tan-?-= 1]
by:
Z = X* X
atan(x) =
P 0 +Pi z + P 2 z 2 _
Go +GiZ + Q2Z 2 +Gs ^ 3
P 0 80.78998484078
Pi 72.5814378046
P 2 11.11774163116
£00 rem y = atan(x)
510 xl = 1
520 if x < 0 then xl = -1
530 if x < 0 then x = -x
540 x2 = 0
550 if x > 1 then x2 = 1
560 if x > 1 then x = 1/x
570 y = x*i
580 x3=80.78£9£+y*(72.56144+y*ll.11774)
£90 x4=80.?£999+y*(99.£1128+y*(28.13286+y))
600 y = y*x3/x4
610 if x2 = 1 then y = 1.5707963 - y
620 y = y*xl
630 return
Go 80.78998647615
Qi 99.5112677199
<2 2 28.13285868067
Qi 1.0
Trig Functions
Sine: Compute as cosine using:
sin (x) = cos (j
*)
Cosine: 1. test arg too large
\x I > 10 d ' 3 , d= # of digits in floating point
then error
2. x = lx I since cos(-x) = cos(x)
3. x = mod(x, 2 7r) since
cos ( 27T + x) = cos x. Range is now
0 < X < 2 7T
4. 0 < x < -y: s = +1 x=x
7r
— < X < 7T : s = — 1
3 7T
n < x < ~ 2 ~: s = — 1
< x < 2 ir:s = +1
x = Iw — x I
x = 17T — x I
x = lx — 27T I
5. z = x 2
y = P 0 +P x z +P 2 z 2 +P 3 z 3 +P 4 Z*
cos = y * s.
500
rem
y
= sin(x)
£10
x =
l.
£70796 -
X
£20
rem
CO
s (x )
530
if
X <
0 then i
=
-x
£40
if
X >
1000 then goto
<error>
550
x =
X
- int(x/6
.283185)*6.283185
£60
x 2
= i
n t(x/1 .5707963)
570
x2
= 1
£60
if
xl
= 1 then
x2
= -
1
590
if
xl
= 2 then
x2
= -
1
600
if
xl
= 1 then
x =
2
141£93 - x
610
if
xl
= 2 then
X =
2
141593 - x
620
if
xl
= 3 then
X =
X
- 6.283185
630
xl
= X
*x
640
y=e
.9999999+xl*
(-.
49£9991+xl*(.04166359+xl*(
-0.
001
365370+xl
*(0
,e000231£393) )))
650
y =
y
* x2
660
ret
urn
P 0 .999999953464
Pi -.499999053455
P 2 .0416635846769
P 3 -.0013853704264
/> 4 .00002315393167
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 15
397
THE DIGICAST™ PROJECT:
AN IMMEDIATELY VIABLE BROADCAST-BASED
INFORMATION UTILITY FOR THE GENERAL PUBLIC
BY JIM C. WARREN, JR.
345 Swett Road
Woodside, CA 94062
This is the abstract of a talk being given before the 2nd
Rocky Mountain Symposium on Microcomputers in Pingree
Park, Colorado, August 27-29, 1978.
Computers have been consumer products since 1975.
Individuals involved in the consumer computer industry
estimate that there are 50,000-200,000 general-purpose
digital computers installed in peoples’ homes. Thus far, these
have been exciting, educational, challenging toys—
to the extent that they have been used for non-commercial,
non-tax-deductable purposes. Their primary use as a
consumer product has been in non-arithmetic or minimal-
computation applications. One difference between their being
an exciting toy, and making them into an obviously useful
consumer product, of value to the general public, is the ability
to attach them to large data-bases of interest and use to the
general public. The Digicast Project proposes to provide one of
the first such “attachments” for personal computers.
The single database facility most widely used by the general
public is unquestionably the newspaper and newscast. The
newspaper provides a large, though certainly limited, data¬
base with updating. The newscast provides a much more lim¬
ited, similar database, with much faster delivery. In both cases,
the database is available to the public only in a human-
readable form, requiring manual scanning. The newscast has
the additional undesirable limitation that it must be monitored
in its entirety by a human listener or viewer, and must be
monitored at explicit times. The Digicast Project proposes to
provide most of the utility of the newspaper; provide much
more content than is economically feasible using newsprint;
provide the speed of access of a newscast; and provide the
data in machine-readable form so that the consumer may use
an arbitrarily “intelligent” intellectual assistant-the home
computer-in scanning of the incoming data. This will be
accomplished at a cost that is acceptable in the consumer
marketplace, using well-known, established, reliable techno¬
logy. The Digicast Project hopes to have at least one facility
operational by the end of 1978.
The Project proposes to transmit digitally-encoded alpha¬
numeric information on FM subcarriers. By the laws of
physics, every FM broadcast facility has at least two such sub¬
carriers that are usable within the laws of the FCC—the Fed¬
eral Communication Commission. It has already been proven
in commercial broadcasting environments that such transmis¬
sions can be reliably conducted at 4800 baud, and some of the
engineers involved have indicated that they are certain that
trivial hardware modifications could double that transmission
rate. SCI Systems, Inc., 8600 S. Memorial Pkwy., Huntsville,
AL 35802, has a printer that includes a receiver for an FM
digital broadcast using a proprietary encoding scheme
developed by SCI engineers in cooperation with personnel
from Digital Broadcasting Corp. of McLean, VA. The FCC
has already adopted all of the necessary policies to allow such
utilization of SCA’s—Subcarrier Authorizations. Only straight¬
forward administrative approval is required in order for any
licensed FM station to begin transmission. The hardware
modifications at the transmitter cost well under $10,000.
The receivers— exclusive of the receiving computer—are
obviously producible for $50-$100. Both transmitter and
receiver software can range from quite simple to arbitrarily
complex. The most simple software can make the system
extremely useful.
The scenarios for utilization are also arbitrarily varied:
International, national, and regional news—all of it—can be
made as accessible to the general public as it now is only to
newsroom editors and reporters. It is delivered to newspapers
and broadcasters by wire services, already in machine-readable
form. Little additional effort is necessary to inject that data
into the transmitter computer for “Digicasting.” The con¬
sumer, interested in specified topics, need only instruct the
receving computer to monitor the local Digicast(s), and save
all articles containing specified keywords. Note that the
keywords need not appear in a “headline;” they may be any¬
where in the article, and will still be noted and the article
saved.
Perhaps one of the most useful services that a Digicast can
398
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
offer is in the area of “want ads.” If one desires a Honda for
under $3,000, then one instructs the Digicast receiver in the
obvious manner. There is no need to waste time scanning
uninteresting want ads. There is also no need to classify the
ads—a boon to those selling a variety of unrelated items.
Stock and commodities transactions can be Digicast,
requiring little or no rekeying upon their receipt from the
wire service. Further, if they are in fixed format, then it would
be a simple matter for the receiving computer to feed the data
to a stock analysis program, again requiring no rekeying.
The system must be financially viable if it is to be a wide¬
spread and useful information utility. It is reasonable to be¬
lieve that it is financially viable. Consider the income sources
of a newspaper or commercial broadcast—commercial adver¬
tising, classified advertising, and subscriptions. Classified adver¬
tising, sans classification, can be conducted without change
from the past as far as payment is concerned, and with vastly
greater utility. The counterpart of commercial advertising can
be continued in a manner quite analogous to its traditional
form. It can be “forced” on the consumer by injecting it in
the beginnings of articles. Subscriptions can be implemented
through encryption of the data being transmitted and sale of
monthly decoding keys that need only be typed in to the re¬
ceiving computer. One subscriber paying for the key and giving
it to several others is no more of a problem than one sub¬
scriber to a newspaper giving his copy to someone else.
This abstract provides only the most brief glimpse of
digital broadcasting and its potential utility and impact for the
society at large. Most of the details of the Digicast Project will
be published in the Intelligent Machine Journal, a biweekly
newspaper oriented to low-cost computing power, edited
and published by the author. The Journal carries discussion of
the design alternatives of the Digicast hardware, software,
systems, and protocols, and publishes Digicast standards as
they are adopted. Discussion, suggestions, and general dialogue
concerning the design of digital broadcasting systems is solici¬
ted for publication and distribution in this periodical. Most of
the information is thereby explicitly placed in the public
domain. Only explicit hardware designs will be proprietary,
protected by the traditional patent process, and the names—
Digicast and Digicasting-are proprietary and protected by
trade mark. Additionally, explicit transmitter system designs
will undoubtedly be protected by their creators via trade
secret methods.
There are a multitude of FM stations. There are a multi¬
tude of interesting and useful applications of the proposed
systems design. There is room enough for all. Let us stand on
each others’ shoulders; not on each others’ toes. *
* almost-direct quote of Dennis Allison in Dr. Dobb's Journal,
January, 1976.
/Vote: Subscriptions to the Intelligent Machine Journal are $18/year
to U.S. addresses, and may be directed to 345 Swett Rd., Woodside,
CA 94062. The author of this paper, the Director of the Digicast Pro¬
ject, will publish all public-domain information regarding the Project
in the Journal. Personal requests for explicit information will be
answered with information about the Journal, due to limited time and
funds. Correspondence offering suggestions may be published. Corres¬
pondence offering experience-based assistance or cooperation is, un¬
fortunately, the only kind that may evoke a personal reply. Please
include day and evening telephone numbers in this latter form of com¬
munication.
CUTTING STENCILS WITH A DIABLO PRINTER
Dear Dr. Dobb’s, Received: 78 July 7
These routines allow you to use a Diablo printer to cut an
ordinary office stencil, a problem with many small systems
printers because the printer head has so little mass, as
opposed to ordinary office typewriters. We used no film in
front of the stencil, and inserted the typing plate behind the
stencil. We then programmed the computer in the system to
output the text to the printer as per the attached program
routines.
The routine CUTSTEN.LIN just types each line 4 times.
This is adequate to cut through the stencil for most letters.
The routine CUTSTEN.CHR does better, though; it types
heavy characters like H or M more times than light characters
like i or 1.
Most computers which allow programming of output
routines should be similarly adaptable. Many word processing
systems will likely require such modification, because the
impact printers used (like the Diablo) commonly strike fast
but not heavy. Our system is a Cromemco Z-2, and the printer
is made by Data Terminals & Communications (San Jose),
using a Diablo Hy-Term print mechanism. The routines are
written in Sheppardson Basic, operating under Cromemco’s
CDOS.
Sincerely yours, 495 3rd Ave.
Richard French San Francisco, CA 94118
» t 72, RIB30N OFF?"
PLATE, IN POSITION?" : @
00 @ : CUTSTEN: TYPES OUT EDIT FILES ONTO STENCIL @
05 REM- VERSION CUTSTEN.LIN: CUTS STENCIL LINE AT A TIME, USING 4 PASSES.
10 DIM F$(13) ,A$(79)
20 SETT 0,-1 : REM- DISABLES PAGE-WIDTH CHECKING.
30 REM
40 PRINTER ON LINE & RESET?"
50 PITCH = 10, WHEEL =
_60 STENCIL BACKED BY PLmt, n
170 INPUT-TEXT FILE NAME ? ",F$
180 REM
190 OPEN\l\FS : REM- OPEN ASCII DISC FILE ON CHANNEL 1.
200 OPEN\4\"$T5" : REM- OPEN DIA3L0 DRIVER CN CHAWEL 4.
210 QUT%0050%,%0084% : REM- SET BAUD*300 ON TUART (I/O BOARD).
220 REM
230 ON ESC GOTO 350
240 REM- IF USER WANTS ESCAPE CO CLOSE FILES.
250 REM _
(13) ;ASiCHR$ (13) ;A$;CHRS (13) ;A$
!60
260 INI
280 eyr
330 03TC
340 REM
350 CLOSE : @ : END
100 3 : CUTSTEN: TYPES EDITED ASCII FILE INTO STENCIL ::::::" : @
110 REM- VERSION CUTSTEN.CHR: CUTS ONE CHARACTER AT A TIME, SEVERAL PASSES.
120 IMODE : REM- ALL VARIABLES ARE INTEGERS.
130 DIM F$ (13) .AS (79) ,C$(0)
140 INTEGER T(127)
150 SET 0,-1 : REM- DISABLES PAGE-WIDTH CHECKING.
160 REM
170 0"PRINTER ON LINE & RESET?"
180 PITCH « 10. PLOT = ON?"
190 §"WHEEL = f72. RIBBON OFF?"
200 STENCIL BACKED BY PLATE, IN POSITION?" : @
210 INPUT-TEXT FILE NAME ? ",F$
220 REM
230 OPEN\l\FS : REM- OPEN ASCII DISC FILE ON CHANNEL 1.
240 OPEN\4\"ST5" : REM- OPEN DIABLO DRIVER ON CHAMvIEL 4.
250 QUT%0050%.%0084% : REM- SET BAUD*300 ON TUART (I/O BOARD).
260 3\4\CHR$(6) : REM- ENTER PLOT MODE. (NO AUTO ADVANCE AFTER CHAR PRINT.)
270 REM
280 ON ESC GOTO 580
290 REM- IF USER WANTS ESCAPE GD CLOSE FILES.
300 REM
310 MAT T=1
320 DATA 3,3,8,9,5,5,2,3,3,4
330 DATA 3,3,2,2,2,8,4,5,4,9
340 DATA 5,6,4,9,9,5,5,2,3,2
350 DATA 4,6,8.9.5.8,8.7,10,10
360 DATA 4,6,10.5.12.10,7,7,10,8
370 DATA 8,7,8,7,11,9.5.5.3.3
380 DATA 3,1,2,3,5,7,5,9,5,6
390 DATA 9,7,4,5,8,4,9,5,5,10
400 DATA 8,3,6,4,5,5,8,6,6,4
410 DATA 3,3.3,3
42u FOR Z=33 TO 126
430 READ D : T(Z)=D : REM- LOAD TABLE WITH DATA.
440 NEXT Z
450 REM
460 INPUT\1\AS : REM- GET ASCII LINE FROM DISC FILE.
470 FOR X=0 TO(L£N(A$)-1)
480 C$=A$(X,X) : REM- SELECT CHARACTER.
49U N=T(ASC(C$)) : REM- OBTAIN PARALLEL NUMBER FROM TA3LE.
500 FOR Y*1 TO N
510 0\4\C$; : REM- PRINT CHARACTER N TIMES.
520 JCXT Y
530 @\4\CH t$ (6) ;CHR$ (32) ;CHR$ (6); : REM- PLOT OFF, ONE SPACE, PLOT CN.
540 NEXT X
550 9\4\CHRS (6) ;CHR$ (13) ;CHR$ (10) ;CHR$ (6) : REM- PLOT OFF, CR & LF, PLOT CN.
560 GOTO 460
570 REM
580 £\4^CH R $j 7 ) : REM- TORN PLOT OFF (REGARDLESS OF PREVIOUS CN/OFF STATUS).
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 17
399
POW:An 8080
'Processor of Words'
BY HERMAN WATSON
P.0. Box 341401
Coral Gables, FL 33134
Note: Normally we would have typeset the text of this
article, but we reproduce it here as we received it as an exam¬
ple of what this program can do. A sample of the “Edit"
or upper case Input File is given for comparison.-TRW
....row_
POW is a program that is a "Processor Of Words" for
the 8080 computer. POW most closely resembles a program
called PRINTER written by Clyde Roby. POW has the ability
to set margins, tabs, spacing, justification, and indention
and in addition provides automatic centering, and automatic
paging with titles and numbering.
This program works on an existing file that has been
prepared with some type of editor and saved on a mass
storage device. I am currently using a modified version of
F. J. Oreeb's editor that was published in DDJ June/July
1976, along with Peripheral Vision's floppy disc operating
system. POW has in the past been used with cassette tape,
and by substituting the cassette I/O routines for the FDOS
I/O routines, it can easily be converted back.
Commands are freely inserted into the source text when
it is prepared. POW will react to those commands when it
encounters them while printing out the file. Commands all
consist of the same format which is a colon immediately
followed by a two letter command name, then a delimiter
with optional data for the command, and/or a terminator.
Delimiters are either a comma, or a space, and a terminator
can be either a comma a space, a carriage return, or
nothing. This allows maxinum freedom from rigid command
syntax. A sample of the command format is shown by the
definition of margins:
:DM,10,70
In addition to the list of commands, POW also has the
ability to allow the use of an upper and lower case printer
with an upper case only input file. This is accomplished
by using special characters representing a single
capitalization, a Shift-Lock, and a Down-Shift. These
special characters are an ASCII Shift-N and an ASCII
Shift-L . One single Shift-N character is used for single
capitalization, and two consecutive Shift-N characters are
used for Shift-Lock. POW begins in the upper case mode and
will remain in it until either a single shift character or
THIS IS 1 Hfc “Eli 1T '* VERS I Uri UF THE MLt US EH FUR
PPEPRRING THE INSTRUCTIONS. THIS IS THE TYPE DF FILE
THRT IS INPUT TO PDW FOP PROCESSINC.
:PT.10*5:PH*IDrO
:TM,48, "POW..
: JT
5PG
i CM* ^_POW_\
>LFV3
: BP * "'PDW' IS R PPOGPRM THRT IS R “^PPOCESSOR ~UF 'WOP
FOP THE 8080 COMPUTER.
- PULI' MUSI CLOSELY
PESEHBLES R PPOGPRM CRLLED ^PRINTER' WRITTEN
BY '"CLYDE ROBY. POW' HRS THE RBILITY
TO SET MRP6INS* TRBS* SPACING* JUST IF 1CRT ION* HMD
INDENTION RND IN RDDITION PROVIDES
HUTCJMRTTC CENTERING* RND RUTOMRTIC PHGING WITH
TITLES RND NUMBERING.
:BP« THIS PPOGPRM WORKS ON RN EXISTING FILE THRT
HRS BEEN PREPRRED WITH SOME TYPE OF EDITOR
RND SRVED ON R MRSS STORRGE DEVICE. I RM CURRENTLY
USING R MODIFIED VERSION OF - S F. \J. GREEK'S
EDITOR THRT WRS PUBLISHED IN "'"‘DDJ J'UNE/"JULY
1976* RLONG WITH PEPIPHERRL ''VISION S FLOPPY DISC
OPEPRTING SYSTEM.
^POW' HRS IN THE PRST BEEN USED WITH CRSSETTE
TRPE* RND BY SUBSTITUTING THE CRSSETTE ''' I -O'
ROUTINES FOR THE ^FDOS I'O' ROUTINES, IT
CRN ERSILY BE CONVERTED BRCK.
: BP, COMMRNDS RPE FREELY INSERTED INTO THE SOURCE
TEXT WHEN IT IS PPEPRRED. ""POW' WILL
PERCT TO THOSE COMMRNDS WHEN IT ENCOUNTERS THEM
WHILE PRINTING DUT THE FILE.
"COMMRNDS RLL CONSIST OF THE SRME FOPMRT WHICH IS
R COLON IMMEDIRTELY FOLLOWED BY R TWO LETTER
COMMRND NRME* THEN R DELIMITER WITH OPTIONRL
DRTR FOP THE COMMRND, RND'- OR R TEPMINRTOR.
DELIMITERS RRE EITHER R COMMR* OR R SPRCE*
RND R TERMINRTOR CRN BE EITHER R COMMR R SPRCE, R
CRRPIRGE RETURN, OR NOTHING. THIS RLLOWS NRXIMUM
FREEDOM FROM PI6ID COMMRND SYNTRX. R SRMPLE
OF THE COMMRND FORMRT IS SHOWN BY THE DEFINITION OF
MRRGINS::LF*1
:CM, s^DMn* 10,70
:BP,^IN RDDITION TO THE LIST OF COMMRNDS, "POW' RLSO
HRS THE RBILITY TO RLLOW THE USE OF RN UPPER RND
a Down-Shift character is encountered. An input file
containing both upper and lower case ASCII can be processed
without modification in the default mode (Upper Case).
Case modifications are only done automatically once the
Upper Case mode lias been exited.
Page 18
400
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
The singlo shift command (Shift-N) will automatically
capitalize only the character that immediately follows the
command. For example, " pow" would be printed as "Pow".
The Shift-Lock command locks the carriage up, until the
Shift-Down command is given, so for example, " pow " would
become "PON", Capitalization commands work in all areas of
POW. Page title capitalization uses the existing
capitalization mode, but will not change the present mode
if capitalization is specified in the title. This means
that when a new page begins with the case set in the lower
case mode, even if a Shift-Lock command occurs in the
title, once the printing of the title is over and the text
is resumed, the lower case mode will be restored.
PROGRAM STRUCTURE
Pow starts with a greeting message containing
instructions, and then goes to the "MAIN:" area to get a
command from the console. The "L"-Load command reads all of
the input file into memory and returns to the "MAIN" area.
Wien the "P"-Print command is given, control is transferred
to the principal loop of the program, starting at "PRIN:".
"PRIN" then gets a character from memory and checks to see
if it is the beginning of a command. If it is, control is
passed to the area called "CMND:" and the command table
"CTAB:" is searched for a match. If a match is found, then
a subroutine call is done to the command routine with a
return to "PRIN".
If the character is not the beginning of a command, it
is then checked to see if it is a capitalization command.
If it is, the routine "CAPRt" handles the case processing.
The carry is set on return from "CAPR" to indicate whether
the present character is to be ignored or not.
If the character-is not a capitalization command, it
is then checked to see if it is a Shift-K. This character
is used to indicate that the character immediately
following the Shift-K is to be output without any
processing.
"PRIN" then checks to see if the justification is on
or off. The routine "UFMT:" is used when there is no
justification, and the routine "TMAT:" is used for both
left and total justification.
The routine "urMT" will output the text as specified
in the input file, honoring all carriage returns as the end
of the line. It will in addition force a carriage return
if the text tries to go past the right margin.
The routine "FMAT" outputs text either left justified
(against the left margin, with as many words on the line as
possible) or total justified with spaces filled. Total
justification begins as left justification, and then
randomly begins filling with spaces until the line is
completely filled between the left and right margins.
In either the left or total justification mode, all
carriage returns are converted to a space, and the
carriage returns that get printed are computed by POW.
It should be noted that POW ignores line feed
characters, and will work with a text file that either
contains them or not. If vertical spacing between lines is
needed, it should be specified with the :LF command, and
not with multiple line feeds or carriage returns.
There are three areas where the text is taken from
memory and used in the program. The main one is at "PRIN"
itself, and the other two are for the page titles and the
centering commands. All output goes through "OBUF" except
page titles. The printing of page titles is done directly
to the printer without any use of the "OBUF" buffer. Title
printing is suppressed until page two is reached. This
allows the printout of the first page without a title.
Since I am using this program with my Selectric
printer, I have included the output routines used for the
printer. The conversion table is included, but might be
different for other machines. The machine is a Datel 1030
terminal. POW itself is written to run strictly with ASCII
code, and as I have demonstrated, conversion can be
accomplished either on input or output to other codes if
necessary.
POW has the provision for stopping the printer and
waiting for the paper to be changed. Pressing the
"Attention" button allows POW to continue with the next
page. The area for that is at "DVDR:", and uses the code
for A.ttn on my printer. This section can be changed to
ring the bell and wait for a press of return on an ASCII
terminal.
The usual proceedure for setting up a file that will
be output with POW would be to first define the margins,
then the top of the page length, with the line for the
title, then the text length o* the nago, and the length of
the bottom of the page. The title can be nut on the bottom
or the top of the page. The sum of the top of the page,
the text length, and the bottom of the page length should
be 65 for a Selectric with a Pitch of 10, or the same for a
Teletype. Next, a page number of zero is specified, then
the top or bottom message is defined. The justification
mode is chosen, and then the tabs should be defined. The
paragraph break can finally be defined, and the last
command before the beginning of the text should probably be
":PG" which forces an immediate start of page number one.
(page number goes from zero to one) The order that these
commands are given is not critical, nor is it necessary to
include them all. POW has all of the critical commands set
to default values, and new snecifications are necessary
only if the default values are unsatisfactory. The ":PG"
command is used, because it tells POW when it is starting
the first page of the file.
With thi3 brief description, the source listing should
be pretty well self explanatory.
COMMAND SUMMARY AND DEFAULT VALUES
:DM,10,70 Define margins, left margin, right margin
:DT,15,22,30,45 Define tabs up to a maximum of 14 tabs.
Tabs must be in ascending order and no error checking
is done on them.
:PL,45 Define page length (the text portion) to be 45
lines long.
:JT Begin total justification mode with automatic
space filling.
:JE Close present line and end all justification
*JL Begin left only justification mode.
:CT,Tab,Text Center the text about the tab that is
specified (Note, the line i3 not printed after this
command)
:CC Close Centering command MUST be issued after the
last :CT command. This closes the output line.
:LF,Numb Line Teed the paper up "Numb" times (Index on
Selectrics). This is really a CR, LF sequence to
printer "Numb" times.
:BP Break for a new paragraph. Since carriage
returns are converted to spaces during either total or
left justification, it is necessary to be able to
specify the beginning of a new paragraph while in
these modes. This is done with this command. The
printer closes the present line, then does the
specified number of line feeds, and then indents to
the specified tab. The indention is automatically set
to the left margin when the margins are defined, and
is also set v/ith the next command.
:DB,1,15 Define the paragraph break to be a number of line
feed's and an indention to a specific tab position
(default is LF**1 and tab set to the left margin) . The
indention can be set at any place either to the right
or left of the left margin.
:NP New Page forces the close of the present page,
feeds it out of the printer, and then begins a new
page.
:CM,Text Automatically centers the text between the left
margin and right margin. This command does NOT need
to be closed with a :CC command.
:PN,0 Set the page number to the specified value (max
is 256)
:SP,1 Set the spacing. If single spacing is desired,
the value would be 1, if triple spacing i3 desired,
the value would be 3.
:PT,LF,Numb Define the top of the page to be LF (10)
spaces long, v/ith the title occurring on line "Numb",
if "Numb" is zero, no message is printed. LF can also
be zero for a page of complete text.
:PB,LF,!Jumb Define the bottom of the page.
:TM,Tab,Text Define what the top of page message will
be. It will be printed "Tab" positions over, and
"Text" will be the message. If in a colon is found
while printing "Text", the present page number will be
substituted for the colon. Example:
":TM,45,PAGE-:-" would cause the top message to be
printed at tab 45 as "PAGE-4-" v/hen page 4 is printed.
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 19
401
:BM,Tab,Text Define what the bottom of page message
will be.
:P0 Will immediately force the beginning of a new
page (it will not finish the present page). This
command should be given at the beginning of the
printing of a new text file.
sOF This command will turn off the high quality
printer but will continue processing of the text as if
it were on.
:0N This command will turn back on the printer after
it has been turned off with the above command, this
allows sections of a long file to be skipped over
after an error has been found and corrected, allowing
printing to be resumed after the error is corrected.
FDOS ROUTINES USED
Cl: Console input routine. When thi3 routine
returns, the accumulator contains the character typed
on the console. If no key was struck, the CPU will
wait in Cl until onp is struck.
CO: Console output routine. The ASCII character in
the C register is output to the console printer. On
return, both the and C register contain the
character.
Cf.TS: Console status check. I* the console has had a
key struck, the accumulator returns with the value
OFFII. If no key has been struck, the accumulator
returns with the value 0OH.
RESTRT: This is the address that restarts the FDOS
monitor.
TXTYP: This routine types the text string pointed to by
the HL register. The routine types all characters,
and the last character typed will have the most
significant bit set. This terminates the routine.
TXTIN: This routine is used to get the file name that is
to be opened.
REDFIL: This is the address of the buffer pointer that
will be used for input from an FDOS file.
FILNAM: This routine checks the syntax of the file name
input with txtin.
LOKFIL: This routine looks in the FDOS directory to see
if the specified file exists.
OPNIN: This is the routine that opens the FDOS file for
sequential input.
FDREAD: This routine is a functional equivalent to Cl:
except it inputs the next character from the open FDOS
file. If the end of the input file has been reached,
the routine returns with the carry flag set.
Herman Watson received his
Bachelor of Science in Zoology from
the University of Florida at Gaines¬
ville, in 1969 and his Master of
Science in Electrical Engineering
from the University of Miami in
1972. He is a Biomedical Engineer
with the Division of Pulmonary
Diseases, Mount Sinai Medical Cen¬
ter, Miami Beach, Florida. Some of
his research interests include model¬
ing and analysis of the Pulmonary
system. Ambulatory Monitoring, and
EEG analysis.
x
z _i
□ ^ LL
I- *+ -
x ■,•>
3 X UJ
: • x ''
□ Lfc ’
■ . D C
ui
UJ
Cl £&
ZL ►—
□
Z
UJ •-*
X lE
X "I
I x
X (-
•X h-
a x uj
U. UJ 1
LL li h
.. □ 'X' X X V) _J H
X' u. ft it z. x _i z
i>i □ it □ to z ll ii •
Z Uj D ll UI D m 111 ll — : : LL
i- cl x co i u I it a = CL
X J ll □ « Z > U z
I— s 1 JD1E / UJ X
h n j w fti I I X Cl ll Z
- LL 3 X CL UI UJ UJ x z:
>2‘ I- I- 10 _! ■:••• ' H □ □ i
/ / / / / / X / / / / ,
OJ rf If
UJ u u
'■'J rf rf
:• i- oj •= if -1
r v u < co v •
. OJ U CO CO
t u- ’t t
-• u. • £' X
J 1 t CO U’.i
J r- o co x
'■<j
•t U" 1
U rf 1
rt rf
V rf ll"
OJ UJ t
OJ CO
CO • M
if Z'
If. OJ OJ l
U X Oj ■:
J rf OJ I
I *t fij ,
I X
i X o
J V CO M U. OJ 1=1
• If 'U OJ rf rf If rf
\ O ' O o x ITU •=•
' rf OJ rf rf rf If rf
:■ If •=• OJ r- ^ ■=' OJ
J UO OJ IT.' If rf OJ UO
jhx^ •=■ •=• v r-
j if •=• y. oj oj if v
If IT' '=■ •=• —
rf rf OJ OJ V
OJ OJ W
V OJ If If rf
•=• If If If M
If t rf |f rf
X CO rf LL U rf
rf rf i
.'.J if OJ •
OJ rf rf if rf ■
- t=i CO CO U OJ u O' M UI X- CO UJ
■|J '=' rf If I "t If rt OJ '=■ rf rf If rf rf
•- . • £. O' ui co co q oj r-
- ~ O _ ^ Oj Oj OJ
O rf O. UJ CO rf |J. UI CO CO t=< OJ r- *•£' Ut ■•£> £0 O If X
*t rf »f rf if U"' U"' If 1 ••£■ X' X fj- K N CO CO CO X' X' X X X X X
402
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
'XI Cj
>1 It ill
H X
■X IX
-« t- X +
' Ui Z. Cl
- Cl X Z. -■ < 7 *
uS'I « 'IX Z.
•X J X X •/• I .1 E 1 J z
Ci it a
I - JL
X _l T _J
I JQ
M M LL I/'' I J LL h It w »—
> X Z :• K I □ IU □ Cl u CL I UI
Z >-l 1 LL X I ' LL X U. X LL
. UJ LU X ' • C Cl
1 —I —I • *- f J »—• •— — IJ h- —'Xu. *- _J _J — L .
ll (_> Cl z. > tx r j a. i □ . c, z. 1 i j x cj z. i ' X .
• 1 - u. " LU Z. _J _l '. t X J Z —• • ■ i l *
. 2 UJ
O |V, |V,
v u’.i cu — - 7 - uj -.'j uj u.
— — •_> UJ "J UJ U. O ll
• r - uj r- * .
"J ll" 1 -X ru U >L •
« N u o n i, r . f . r. i
OJ
^ 'I LL UJ f - CO Cl ■
I-.J |V, rf f. ,-,j C .
I UJ "J 0’> If' •■£» CO '7-
•x ci rf U ' 1 - 'J.ll ''ij u"' cci uj ^ rt n .7
—• — *'0 '"'J '"'J **'J 'U '*'J "J I'J •‘•J ••• ft rt «t -t r t
•x x —<’t -v <7 x
*t ’fr *t If' If* If' If' lf‘ If'
J UJ le. Ll
i h- 'I I'
: <l z (A (■:• « :
- □ ci x a □ d •:
—I LL - J IX • ■ i
\ =■ x z _J X •:
Z* _J © Q
□ I LU LL
LL M It h ■ Ui > LL PJ > X I—
□ O □ Z Z. LU N □ I I □ I 111
> k *r z tt *- it iu z '_' ct n x
X *-• > '_' X 'X > ►
XD JZ J JliD,
x —j z x • x x :. z >:
(/) Cl
« X
'X K JQ
• — r j ►— x hxl'Ih j jh
X Z EOXZZhX'IIUJ
• “i uj “> □ _j u _i o x
x a
□ 'X-
J— Cl I XXX
Z> 'X •! K X X
Cl Cl X N ■ J -H
c- Cl ru If* 'I Of
r - cu r - r- o r -
r - <x x i-i x x o ■— of
Xi Ci C* lm Ci Ci Ci
'_' M X - 7 • £•
'_' '.' Q Q M
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 21
403
u
□
tt Z _J C' - ' Ll is- - ' _i
IOE J I- H 1 'T j D Z> X
■ • • X □ Z> _• X X * X x a. •
i i i i u m □ n i '••• •.* u. -i ll r :
* -i r a:
• m x r-j r
: j D ■ w '
: <x _i > -X x :
• i— X r j □ h-
' •' Z Q k
: a f ii- x :
i i il i ;
J ~• LU — ►
•o v co X
n .-.j r~ .-j
^ X 00
X| oj c-
•=• oj r--
X Cu OJ X Ll X Ll X
CO X CO ^ i_. mj oj ,.j
oj n oj -h r-. rt r - r - r-.
X X 1 »- X
If- t X'
OJ OJ OJ OJ
I '"'J X ''J 0 X ■- X *—i OJ CO X ill X LU M OJ w X LU OJ CO X P X '7- X X '"'J CO CO X f- UJ '"'J X O X CO —■ X CO X 'X « CO M X X M 'I • > oj r. X "J Q OJ ro Cj _ ,t
X CO x i_i ro i‘m i_i ro x co r- co oj o co CO Co co «_> cij o f -_ ll *_> X CO <j oj r-. oj x O o CJ co *r ro -”i co oj * iz. c i_. i_. ... ^
^ co 'L' CO ^ I_I IX O CO X' '7‘ CO X OJ HO CO <J. <_'»=) X X OJ CO X' '?• X h X X c H OJ Tf r-._ i;o rr. i_j X OJ CO rf •£. ij. i i ll OJ ip -J.' 1 O. . . Q O O', rj r ._ ^ LU _ rj
• X X X X X X X X X X X X X X •=■ © O O O © O *■« *-**-* .i —• — — OJ OJ OJ oj OJ OJ OJ oj CiJ CO O'' CO O'* O'* CO CO t 11 rf i t U', u'i IP u IP ip IP v X
‘ T Z Z Z| Z Z Z Z |Z Z Z Z Z ‘!y 'i* 'i* '[y 'jJ OJ OJ 'OJ • jj OJ OJ X OJ OJ X X X X X X X X X Cij x ijj oj Oj Oj Oj OJ OJ OJ OJ Oj Oj Oj OJ OJ 'jj OJ "J Co oj oj Oj oj Oj
x z: a
“• - o x
j 11 - j
Z. X
' •=- .1 f—
Z LL IJJ G
■1 X i
Z' r- X
Z _J Z PC'I •- 1
•I X X 'I X • » X
Lt • ' I J _J X
M i Z*
h J h tf, □ x ;
X X > X !
J J Z □ h O '
^ -I Z> - X
P •— ZL • >■ h- h
' X CO C X X 'X -- -• N
: x := x z> j z j w ii ' j x z .
... z: x 1 —| t— 'i x .j •_< “ “• ■
X XHliil
Q X D I a
h- Z X h- h~ <_• (
Z X Z Cl
'I Z- h-
X 'X
X to X
' x -X
U M X
• 1 • 1 X X
• - a a x
j cr j i j x > —
•x t- i 'j i m o
• .J -j _J Z Z L
X CO X X CU X
CO CO Oj cu oj oj ro
— r - r- r - r - oj r-
* ip 'i co x x co x <x cr- cu <x •-< oj x x *-* cu cu -o
' CU r - oj ll f- CO C 1 * 1 <7- CO rf ro rr. m -'ij ro
X X -X X OJ
CO X X
CO *7- 'I O X ■- CU CO l >7- 'X LM o X —' OJ U"‘ CO <7- OOhI \-.
CO or* CO CO CO .7 .7 . .7 . *7- <7 - >7- cr . ‘7 - *7' '7 - •! -I «X 'I 'X *1 'X CO « Oft «
. 7 . x •- co i r-
Page 22
404
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
r j *1 z z. 0
r_i ixi «I
£1
a
LU
Li.
□
LU
— LL
LL □
J- X
X
U.
a
lu a
) <y > u.
• LU
. □ LU
X ft
a — cl t a i
r - 001 ft _j a.
• lU LU <j Z. • LU -
K X
X •! Cl
a « lD
•X l
ll r J ,
□ Cl
~ 0 □
_JX — C
UJ X
LL I— 0
Cl □
UJ LU
'X a
'X
: b
. UJ LL
X h-
!=- p‘
a j-
CL * ' L
Cl -X >
LL _l
a. •
► 'I x ■
■i i o 0
- ^ P ^
o I j. ,1 ’
> J J - N M J M li ,1 ,1 > 'X LL _l LL f j ll I I- ll M > .I_j.lL
.5- 'I 'I LL Z > '1 / . Z. O CL I 1 □ Q Z I I 'I ; CL K iu w Cl l 1 □ H I m i
■ z _i *-i _J O ' X J |_| tfu ■*' x LL _J O CL X I ' _J _1 ►
X
' ‘X '
) M Z'
: _j a
— _j cl f j :
> 'luxe
x <_• 1=1 -i:
•i i >
*- 0 □
□
Cl
■ □ 'X •
•I' -X
— Cl
•• 1 CD
I H Cl
I- — K
Z
•1 i-i •=■ — n f • a-
= m lu UJ UJ LU lu
•»J i'U >jj ft '''J OJ i'ij
— -X
1=1 UJ
00 OCI
o O i
N
OJ ^ ft
UJ M M UJ I'IJ UJ 1=1 -I
ft (J LL ft »*|J
O 'X
If' l_l
rf . 7 .
O nj cu
f-. f - f -
-t •! r- ix u. -I CT '0 0 cu u. oj ft x uj co ft <-u >x -
ft ' v ' uj I_I rf >:•*! uj I_| I_I O I_i ll ft I_| ft ^ q f._ ,V| ,-g ,
J. Uj UJ — f> sill CO lu uj U. OJ CO •■£• f - 'I w UJ u rg y. ft a. •! m u. '=■ u tj k
LLl LU Ui U. U_ Ll Ll U- LL LL •=' '= •=• © O O O ~ ^ ^ ft ft rg rg
ft i’ij ijj rg ft ft rg rg rg ft iYi ro r.‘. ft ,v, ,v. ,y,
in CU LL -I OO LL © I\J 00 U- ifi Tt
•=> uj cu uj co '■£> if- ui co eg o ©
N r- co co co co co r. ro r ._ n_ r_
=• o o o o o CL 0 Q o o o o © ©
CU ft C
U. I b‘ UJ P m OJ UJ CTi P I UJ 111 1 P ft rg rg x LL ft
rf co ll co o 0 r- oj o o u. u. _■ <_• v *ll co _>
X P UJ U. - 'f IP ct' a. 1 P o i-g tf> N 'I 0 =• ft rf r. X uj I_| LL
eg 'Xi rg cu co co co co co CC' co rj rj -t in in y* /■ y y y y*
CO CO co (O co co i "0 ft CO I V I (O' co ft, ff, ft, ft, ft, .V, ,Y, ,v, ,v, ,v, ,v ft, ,v,
•=■ •=■ o o o o o o © © o o ©■ © -■ t p. C' c r- c b c
rt r -
•=• I-g
r - r-
0
x
-I
UJ LU
'X P
1 Z f-
‘I X <10 i'L UJ •
•I
I Z 0 1 it
•I u
-i *r k
• > U. _•
it t j D •_ ■
-J 'X > X
• I 0 c
0 _J X 0
tb
□ Q
ft X
a
»x«
D Zi
ft 0
ft
(X 0
X UI J- ft 0
ft 0 </. 0.10
ft 0 LL I * Z' LL
Cr;i IT '7 0 0 X a 0
0 0
UJ CO
UJ
I 0 'I 'I 0
X ft 0 UJ
I .o X ' •* ft
1
0 X '0 ('»
UJ Ll :
t D
<X 0
X
ft >
□ *-
UJ - 0 >
'I
ft X (/) co
0 ft C D
I • ft ft
I 0 I 0 ll 0 X X
0 LL LL .
0 0 I
Z' X -
U. 0 X I
a -I
a.
X
D 0
J □
0 X
ft ft 0 0 ;
□
0
Q
> 0 *-• 'I ft 'I ft ft Z> 0 *— a. Z' ►—
UI ft N ft x □ f J ft f .j z X X 0 Z 0 X •_> i
0 X i 0 X ' ft ■ i ■ 0 0 »— i i 0 a. [
•I ft
0 X f J
0 LL ft
ft
I- U.
. Z« o 'X •!
a 0 ll r
' LL 0 CD
□ o
r - 'X 0 LL •=' Oj ' ' . rt
l •!> l u v r - r. r. r.
' 'J |- g OJ rg rg rg i'g ijj i g
x —. rg 0 -X .1 f - 0 CO 0 rg rg ll ' 'J CT.
— i'O nj uj ij f-_ rg o i_i rg iX i_i
r - co 0 ft = co t y< •£• r-- oj 0 uj ft i'U
f - r - r - r - r - a- co oj o:* co o: ft ft oj ft >?•
.g oj rg ft ft rg rg ft ft rg rg rg rg rg rg rg
ft O 0 O O .i
— 0 UJ
ft o OJ
r- k r -
UJ ll UJ 'X r- iX UJ ft ft rg ^ rg t
Ll LL OJ r - 10 ft rg rg rg ft ,
ft IT 1 00 I 0 UJ h CO t y, iYi lu LU U "j rr, .
a. a- ft ft it. a. ii .x ii 'X a a x .1 0 0 i:
(U CU Oj oj ft ft rg rg rg rg rg rg rg rg rg rg .
o o c- o o o c ■- o ■- o o -r ■:
y- ft x
0 0 0
CU 0.1 rg
l_l ft rf y-i .£i ,
0 i.
OJ CU Oj "J oj rg ,
uj eg if 1 L'
k-l 0 0 0
rg |-|J rg rg rg
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 23
405
■X X X UJ
I
X t- X X
_i uj
x uj x
I H it
H X> *- LU
X D ~ X 3
"lira
x x x x
X •/'
- x
•>•• XX -•
X
□
X 1=4
UJ X
N □
UJ D >
(-:• i- x
xx xx
UJ X (J X X X h- ■=• x
x xi x iv. x x oj x a
X X X —J » •- 1 X X X UJ - »
■_> uj X x t <_■ in > x « co x ■:
3 Z X
□ v> a uj
< X X ~
- i- r j x n x I
: i,i -1UIU.Z >_• ~i ■
x •-
X \—
X UJ
1 UJ •- X > X
X > X □ h
1 uj z a z h
□
UJ
-J
_J •/>
□ UJ X
X X <
I
,1 x X M X • X X X 1 J—
x z ci x r -j > z > t- i- ui
' X “ </> _J o “■ Z “ Z IV) • . X
□ ..
X •>•>
x X
1 5*
■ x 1-1 :
I- I- X z z X
Z X Z K XX
X • t- » X Z h-
x u x x x x x x x a j- x x i '
-I X
:• —j x
• X z
z
J X □
□ •:
□ :
> x > x _j *—i x > x xxx x x :
□ z □ z x x a z x ii z r j — z z ;
Z H Z H H J □ z H □ “U -I It H H I
X
□
a x
x x x x
X x •_>
in 0
r - rt
rt U‘<
CO XXX 0J
r - x ci u ci
X
IT' -H CO U"<
o r\j oj o
N rt rt r-
'=' «-4 O 0 ro o
o o o
x x x x co x cu r - >? •
c* x co i_* co co co o
CO X X' X U X ^
xxxx xxxx
CO CO CO CO C'-' CO CO CO
rt X' CO CO
xxxx
co CO CO CO
X X —' ’T ■£•
x u o o o
CO CO rt rt rt
•J. 0 c_.
rt *t
rt rf rf
rt r- x* o x co • £> r -
’t’tTj-TfrJ-rf’trJ-Tj-
O O O O O O O O O
CO X X CO X
0J CU OJ CU CU cu
rt ^ rf rf rf rf
cu co rt in oo x
ro ,V| ,V| iy, ,v, ,y,
’t rf rf rf rf rf
1=1 X X CU
co CO 00 CO rt
rt rt rf rf rf
X' l t
X X
It l I
'I i
h-
X •—
a z
a
a x
_j x
r x
x i •
•i x x x -x □ r
-Jj Z'
x x
h- Z
'I i D j □ >
> t- I/'
X L> X
'I x a.
Z u. X ■
X X □ X
a x x x x
□ QJ X h- i j
-I 3 _ X
X w _■
H M I X □
Z Z i <: - .i
X X D
I—I x X X
Z X X X *
x — i □ cl r x
X *1 H
• x x >_• i—i ;
u in UJ i.
V X x 10 x Q
□ z x x
z X *t
5 Z&
x z x o;
■ 3 □ J Z •
•X
Z > • X 'I
Z *— X
□ X X X
j- X -
UJ X
X t
X z
: x a - ;
. □ z x i
- z u u
■ 'X o I-
i x . □
I Z '1 UJ
. x x ;= .
MitD.
' _J □ Z .
Z' I- X
D X • '
X
^ 0 . X
^ ” x ••••
X X X
Z X- X 3
X UJ
X J— □
X z
X X X'
X X
cu cu
N CO
•=' ■= rt X o O X
'.Jj co '*u
X X X 1=4 X M jj <7- '•£' rf i
;• co co x T
«r - ■_> rv o
co —< x
cu x <7 -
X — •£• <7 X X •=• — ro rt u - ' CO O' XXX
■£• r - r-- r - r-- r- >■- oj co co co
ro ro ro ro o'i ro ro ro ro ro ro ro ro ro ro ro r>
rt u - ' CO *J. XXX •=' —' oj i;o rj- u -, (J-, <T
CO CO CO CO CO CO co |J- O' |J. .T. IT. IT. |J. |J> if-,
x x x •=■ cu u - ' r- x x
,T, .7, ,7. -T x X X X X
Page 24
406
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
z c
—' lit I
■X D .
□
N D !
•X > IZ Z'
11 li : ii : .
; H U r J h •
• Lt •! a >T D •
’ I
« j h j ,
_l > 'X x .x i
K □ LU Z._I aJ ►
Z IIta.LtlXLta.LtU.LLri.LtLta.LtLtLLiXU.Lta.
ggDggogpbQggDggggggggggagDD^agouQc
■ Ll) Z
'* t- z
• a
o •_>
w tu «t
rf <X>
•=• LL o Ct
— T t. I.T.
(X, |X| MJ CCi
’T ’t t ’t
It — rj L' .T,
*t rf rf rf $ •*
•1 Ll ’t
'J U M M
n ’I rf rf rf ’T
*t Lt t r- ixi 'X -X >x -x x ai • rf i i r .
? u ' 1 * f- u'* lita.iiiiiftt •=•
* y n y •_« y x y u'- u' 1 y rj- y . t -, ..£■ '
t •- U'- - *t O y - 1 rf ■- y c t c
1 i 11 yi -t r - u‘-
cj y u- n u'' i in i ixi
ji* r - y ' v ' in £■ ■£> it ti
*t - i •- i - i -
f_- I?, w IH li -r-t |V, U", f._ iT, ai H Lx H I/, y f._ ij, A H Lx O’ i y
MMuACUjLUAlXJLxlUJLUlxJLxU.LtLXLXltLxlX'- O •=•
lltllll’MIlllllll’MItLi'. I)’, y
ii ■ u u' u u - ' u y u' y u u' u' 1 u' y y u' u'
a z*
lx _J
•I
Lt >
□
UI it t
O Iti X
D Ll It l
z a
Z W ll l- 1- It
□ r- O Z Z lx Z ll
jl- -I - - UJ LL -
i *- mil it x «=i -ixi
_j
I
z z
LL -
I ‘X <t< .
UJ it Ll
X □
Ll ll
ll a
J h ll mi
a. j u
z* UJ II '
u II
LL LX D Z
x — a x -h
• _i *x _• *
X uj a
C' it' □ A i- _j z
- X - z □ z-
•I - Cl _J LL a. '
Z Z UJ I ll Z Cl
'X
. z f j uj z z :
z
Z ..
a z
□
•- k x g z z
UJ it
_J LL
■x o z
- x .
UJ Z I
It •— t
>1 a- .
•X > > X _|
'mac,
- x j x ■
X f— _i D J
•- C I _l ►
fu _J > — < i Z J ll -- r.j i— _j>— _j_i_jcl*-'
Z <1 o LL Z Cj X Z a Z 'X X I ll 'I £ LL
'j. <x
Cl' rf y
rt rf rf
rf rt rf
uj ir.< -I ' li — y iti
If.' *'U U‘| I'lJ C'J OJ UJ UJ UJ
m UJ lx i-' CO <7- ll it
i i i u' u'i y u'i y u'i
rt iIQLUU.
•£• £ £‘ £ ■£ •£<
*1 1 t 1 ’t T
UJ U*' x -1 •- i
I'U U' I -
. .7 I.T .J.
•t *1 h
U'I U'i i=l X v
uj r- 0*.i lm »-h (
•t 'T. r. rij r
• 7 ' a. -i *x -x x -r
t i t t t t
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 25
407
. j. D - Cl UJ z
i -I > :
. x o .
I '— 1 Z *■
1 Li. -X -I
£
•X I-
- UJ
Z U.
-• z
□ Q
LL
I- Mi X
Z □ I
CL » .=*
•I I 'X
•I
• r,
•X
1=1
'X* UJ
• r j o. >
. z Cl
• * uj z
■X LL > -I ►
ll a. □ cp ;
n cl z j •
i x _j > :
i o .
• _i z *
LL
LL Z
X UJ LL
•I Cl M ►- Z
<£• Z E
: Cl ui Cl
I -J h-
■ >£• LL
•X* E I
IldJl
•I •£' .
» a
O E
• -lIGt-
J UJ □ J U.
•i j a c a x
• ll Cl u. • IU
a I Cl X Z Z ■
LL X '.
-I Cl i
a. *1
—J Cl
i r.
'X
Cl
•X
a '£
“• CL
ja cl t
•X I- Z l
I_. IV. I
Z _J •£ -I
■ Z 'X X
: □ z
.=• _* x ll a — .
LLf'iDluTh:
C a Z _j •—• • • .j >
■ I- D
: ” ••
i □ U. □
^ J> •£• =• -I M >X
U. •=' T CO Mi O
•£• r - :p j* 1 f- oj r -
* "J =) OJ ij 1=1 UJ x
_• -‘'J •=• '-'J
UJ co CP >x uj •
K OJ 1=1 •=• u. '
•J- u'< r- >x
<= CO if' 'I o
rv r- n •=• r-._
UJ UJ
CO ll"’
UJ ^ O •=■ ^ iT , CO •=■
UJ Ll OJ fO LL ■=•»-( |v,
Uj ■ £• r_. u~. ■£' r- •£• ip
fP «T .
Mi •=.
oj r -
t f - X CP =• O ' •£■ CO Mi (_• 1=1 '=• CO rf £.
lii Ui Mi Mi _. !_• I_. U & M M M
if- IP uj if.' jj if uj' o'' U'- if* u' u' if. u'* if*
•7 f - U. l£ 1 ^ OJ - O Ui >1 UJ 0"' P 'I UJ CO OJ <0 or* Cm oj CO Cl lij (=, |V|
r - Mi —■ co lij oj >_i uj oj n oj i_i 1=1 u. ^ oi .V,
2* '5 O •=• — t N 'X Oi UJ U. •=■ C'i X' 011 <7- 'I Oi UJ —• ’t N 'I i=i o
wmwwmUJUJUJUJUJUJUJUJIi Ll Ll Ll Ll Ll U. Ul '=■ •=' O O O *■«
U - • U‘> U' 1 U*' if' U*' !!*• I)-.' if* If' If' if* U - ' U' 1 U - ' U' 1 U~' if' If' ll - ' If £• £• •£• '£' •£• •£'
'XU. LL •=• UJ
OJ OJ OJ
•t r- r- r. oj
i -1 r - co u. «=• *x ■
I |V. iCi rt •_! O', . •» >
■X mi u. oj
W r> H H I'lj .
£' £' £' '£• '£■
'■£' '?• 'X Ci UJ U.
OJ "J 'ij OJ OJ ' 'J
'£' £' •■£’ '•£' •£• l
— OJ ■=■
LL OJ U. *''J C"
■•£' r- ■£» r - u''
OJ if' CO Ui UJ
z z
Cl *
•I -I X
z
Cl Cl
•I '_
uj j z a. z *jj cl mi
MMU.UJI=Ll.Jd'll-
Z h- > h- 'I Z LL
UJ O CL lu » '£ Mi
□ '/•:*
u. z
it >1 □ j; Cl 1
1 •£ I i
Ml » Mi I
»- Z 1 •- I
x n z i ll r j ll n i
• — □_)> x - M
j a. uj j a a j 'i •! .
-J— •! z z -I h- j— .
•i • • i
•- UJ
UJ 1=1 z
y> uj —
^ Z •• Ll ••
—I 1=1 Z •£' UJ LL
Z - -I C, 'I
•I X Z h- 1 .
ID
u.
•x uj ' oj uj
oj r - > u oj u •_>
a u oj .-.j..
•I UJ • ■ • UJ CO UJ 'X' Mi ij.
"J f - OJ Ll U. 'ij
1=1 CO Ct ■
'_' l_l I
I_I OJ *-• M M 'X '=• UJ L
LL OJ Ll •=' Mi ^ Oi ■=• .
'•£' r - r - .£« r- oj — uv r . r
i oi — 'ij Ci oj m P X I . i
l lij OJ |_, f.. Oj (■.. ,■
'=' 1=1 '='
CO Mi 1-0
r- '-'j ip
■=• Oi u‘‘
0 . o*. ro o’.
u'. ui Ui Ui
if If' Uj Uj if if' U’ Ui U '
' I P w U) OJ CO ••£' O' LL Oj u - ' CO Mi UJ *t V- «I CP •=■ ro •£. f-. X m ll "J U’* f--
Uj U* IT' ui U’ £• ■•£' •£' •£' •-£' V- f - f - f - f. CO CC* CO CO CO CO CC' CO '7 >7 <7
U_i Uj If' Ui If- If. if If- Ifi U‘- If* Ui U' 1 U'' U*' U'- U' 1 U'' U'' U" 1 U"' U‘ U' 1 U' U'' U’
? i 1 11 1 uj
'I Mi UJ —•
•X 'I >X CO
If' If' If' IP
Pane 26
408
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
1 ►” XI-
•I 1 ' HIU'I*,'
Z- N
J ^ u. I i I-
- u 'X H Z it 'I
• -II Z- D -1 X
i z y- a z z h-
Lu u ‘S' z a i ►
H L 1 x 1 I- 1 ,
Z O it -
— D O h a £
'Z-u.f-_J.tZ.LjU'.
u D • ■ •! U D
•i u a 'I j. ii -I a l
•I 'I 'j □ □ I t- »
u. f- X ll Ll
- Da u. l
t-LLU lb U. CD I- I- V
t- Z X ZJ JJ • • Z 4
'L U' LL _J 0.1 X LJ l
-J LJ H Z li.
_• u.
U lb
1 . u u
Lb l£. t-
U _J I 1 a. . u a. x J.
” a i UJ d •! Z L_ Z Z — u- -l.
Z _j -1 •- ui ^ - u.; tr, ,i ,i ;
Cj f- — -I _j .J _j L J. *- i- i
*- Lu a- ►
ui >1 LX Z a LX •! 1 r ll f- *
cl >x u a i l; a • • - a u 1
•i Da-: a . .. s
l _j ,t — z lj u f—
i- i
Z LL
Hli h£
L L -■ LL
z i i i
UJ 1 J u Ll u
<=• • *- .v, u u
I X -X I i UJ —■ —• c -
a -X CL z- -«'X a
lb Ll' UJ UJ JJ Lb UJ Lb Lb UJ lb Lb Ui U' Lb lm w Lb Lb LL X IL lb lb U ■
1 -J > 'X .> X CL 'X J- > > > _J > > > _ > _J _J > > - - - - - _
‘X ll_ U I j C_J Z u,u.u,wJ(^u.iLii.ujauJUJU ( diLii|jju, l u^, lL ' UUlUjl . ll _
' -'i-iJi a a H ll.
; ai a. uj lx- ij.' w a.
lb UJ •• f— 'X 1 lb j_ X Z. f— Lt_ U U.
a Z. I- • J O I K i I ij I
‘X u U O U • • '£ U Z '.J li' Lb E I l-
•x* •» _j Lb cn ... . x _j ... .j x k-
ib ,r IL K x LI I " 'b U L. Z XX
—j 'I □ U O Lj L! U J a a U '1 Lb x •! • . ‘b »
►- ,i »- j. l -*■- - iu u. _j i _j j .t Z *- - .
"J 'X' tj- LM UJ
UJ UJ UJ lb u: Lb
b b 'b •£' '£■ b
— l - 'I W L' M UJ U.
lLlLlLlLU.llU.Lll
'£' l i b b •£• 'b b b
^ '!J Z’ ? V.' i' Cj 'i‘ -I '-I w UJ U — — 'ij m a — "j 't ll" 1 i' i .1 u.
~ :f L* f _- r _- [_* L: t- L r _- r _- r _- L* r .- r _- f _- r _- f - r - r_- r - f ' r*. i - 1 rV r' J f' J f? f
□ Q .X .
-J CL X C
•_ Lltfii
u • ' JIEI
m □ ai i- i
:> j uj j uj i
«-* •_* Z £L O .
•X 1 Z 'X' Z Z u
u b u X u
I J X O u
•x »— *x b- .. a
' L- 'X X- X. •—I
UJ X L- X I
_j x rj —
_» _j
_J _l 'X 'I
. ' J'l'lMh
Z _)
— ' i _i t— CZJ I 'X .
CL l 1 Ul I* 'I h '
rf h ij. i' r i i.'IJ 'X'
U*i i‘ij 0 1 ^ ll J Lb |V|
••b r - r - b r-- u*'
•j' cd *x •=■ '7 •=•
lb CD ^ Oj •— r r i
uj .-.j -i r. r-_ ■£, u‘>
— b - a- u
LL '''J T 1 ' ''ij i_i
i* f- u*' u _i r - i'
•=. •! r - >L •! "J CD -I i
-< ”t r - 'X' Cm UJ — *t f - 'X
*T *t t *t t T u‘. U"' U ' U*i
•b £• -b •£■ b -b -b ■£' •£' b
w- -r o X -r r- •=' •=• o •=■
W - t f - 'X M 'X |V, ' L' 0 CD l
U‘ v£i •£' •£• •£• •-£• •£• f - fv f. r. f. | . i
.,£. •£. £. •£. -£■ X X £• 1
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 27
409
□
_J
_J
r
a. x
j— — , ,
ll I _
x a. a
a
z. x
- -X
•I
LL
LU
X X
«x □
I X —
I X LL
. -X K
(J
I - LU
. V> _J
. “I UJ
a. uj
k o
x -I
I <
•XI
. X 'I
• X LL
X
'-' U W M I ,
I X X X X X X -X XI
' OJ X .Tj z OJ X CO X
I X
H LL C
O X — X - .
• ’ * 1 ‘ • L
•I CO «X X' I •
•X I
-J ’ -•
X* -X CO
•X J 'j I i
• LLl • M L
• ' I • • •! O '.
ofi
XXX
• Cl Cl ll :
x *i a □ i'
*- - - ~ XX- Zi > - r j _ _J ;
x NX r j x r j « x z N © □ z > x > <x •
x <_:• “• _i x x '*• uj e i z ■ z
' X X X K
. r j o □ □ x
• X X X Cl
’• X
: a.
• X ill »
X
X
X ' *
□ X' :
X
X H
□ >
x x
•— —• ' ' M
X X X □
OI
IT*
rt
rt
o
CO
O'
X
00
00
CC'
X
CO
r-
CO
o:-
'»•
CO
X*
•X
— o
o
o
o
o
X
o
C'
o
O i i
CU
"J
"J
CO
X 'X U"'
U*'
U*'
O'
•£>
»-•
O'
X
X «I
X
•I
X
•I
•X
O'
•X
U-l
X
u •
OJ
**■
r-
rf
X Lr
X
°
X
Oj
•I
X
f -_ XI CO
CU rt
U"' N 'X
X
Q
M
X
o
•v, rf
If'
'-£' 00
X
X
o
IP
CO
•T-
rt
rt rf rf
’t
rt
rt
U"'
U"
if-
If'
If' IP
U"'
If'
'•£'
•■£'
'£'
•£'
sO
• o ■.£' r -
CO CC' CO
CO
CO
CO
CO
a* cc-
-!
CO
00 00
oc«
CO
a*
0'«
o
CO
CC«
0j
CO Oj CO
•o
CO
00
L — *T IP CC' 0- X X X o
- CO CO CO CO CO CO CO CO O- O'
i 1 co co co CC - CC' co co co co oj
z
I. I
□
X □ X
I X x
-J 'I I'
:• x h-
X t— X
X ID ►—
—• a '
XXX
_J _l _l
a o □
</.• i/> •/>
XXX
a □ □
x
xxx
x - t—
. •
X X
X X
— X
X XX* X* u
> - X £ □ XX
Xj-X_J'IX — X
X X — 1 X x
-JHXXX*- X X
XXX X X- (/' u.
— X'XX — xxxx
t— XX—<LLt— KXX 1
XX' X X —• X
X JL D X
— 1 '/> X _• X
G □ X X X Z Z U
X — X I X •• — — —
x a u x *■■} x x
UJ xi
X x
X X
X X
X X
x
i>m • x
i a x X*
X ' • X
1 X
»- UJ X •
X •_» l
- x x n xxf ii-xe-
• X □ »=J X X 'I X Z Li cn X
x j tz •rj ' l x x
XXX
— •£•
• 0 |V '
I rt
X CU
X X — r j X
*r x z z
X u “•
IIIXXXIXI
u. O' t X £• 0- X
t rj .£, f -_ •£. r . , 1 j
II II II II II II II II II
'XXX X Z X
> X X X X X — X — X
j —X > —'LLXXXUL — L
' X x I- — X — x M z. ■
x — 1 • . : x —• x cd x x .
1 X I I- h d U. w _J — ' CD •
j X z
i D
* ' _= — X X X X X
■ c x x x x x •
• X X X X “•
X
X
□
u.
X
X
X I- X £ X
• X X X - L X X -
□ X I— —> X X > — x
X X . X jt X t- f- M
x l-j x x □ — • x —• ; . x
X
□ .
*t CO O' 1 W U” 1 ' U* U _l
oj r - f - ''u ■£' r - o •£. o
CO • — 1 ' •— 1 co • co ■ cc*
M Q — O 1=1 O I Zt O
^ M P I W 'I H 'X M 'I O '
• 'J OJ c. L I_I
I- 11
x i- ;
— a :
X X
(-
H X X
00 <=• O ' —
CU ’t (J'l T Tf
rf rf X .£' X o
U-« IT' Tf Tf Tt ,x
— O O' O O X
oj oj oj co
CO 0*' ' , T ll" 1 U" 1
*r u"‘ oj it- -t t
r - O ' u"* if *x l
U"' t ’t ||‘| 1- t
■u *t l - CC' 'X X X X X I
Uj U X U. X Ll X X. u I
r - r. r. r - r- r - r r- r. i
LL — OJ r-_ — •-£'
X X O-I CO rt
r- r- co co c- o o
IL O' t O (=• »'0 •£• O' -X
rj rf L' r . '£' f'. r - r . i-i.l
if' x x — r - ‘X x ■
o:> o: •» a< co o. oi> o: o:- ■
rf iT. LU 1*0 'X' M
OJ OJ OJ co ro CO
co co co co co a*
Page 28
410
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
D
X
• ' X
111 h-
U □
•x > *-• _> x n > h a. ii a. h
X li 13 . . X ■_ X O Z □ □ Q UJ
O li I J I M "| £ if Cl iL li It
a. Lii H X*
LU ' • • K
_J Uj I- LL ll
lii it lU □ X
LL _J
O UJ X
LL LLI ' '
□ XX
J UJ li LU •
ii li n i j
•I 1=4 Ll I-
— 1 ' LL' IX
X C! • • X •
i- ii r i- «
i *x >
r - lu
£ a
MU
u* x
iXiii
i r- -x »
co
- •- f\J 't
i i
i r - i
4 MU I
3 X
• *1
:■ U’*
£• £
«’.
t- £•
1 I 'I M I 'I I
' □
> ’I
x g
i- r
i x
' •J □ i i
•1 LL L
□
Lu Ll
•'•J U"
mu r -
x o:<
T IP
x <x
oj u'<
X
CL
OJ
■X
n
•■£• • • •
r _ rij
a. r>->
r- f.
• 7 - '1
’T ’t
'i J 'J.' ’I r _- '? 't 4 W X ^ '" |J ,v ‘ ^
>7 a. .7 .7 .7 .7 .7. .i .7, ,7. .7. ,7, 17.
Ifi -X
•7, .7
u-i x
"J ''Ll
. 7 . a
MU OJ
t U*
•T. . 7 .
a x •:
x ll ;
x -
x r-
•=4 Ul 1
X X
11 (l m a. 1- _j ' 1 <
Z Z D X XX
w x > X _J _|
I'l (ti CL I I x K H- J I- 1.1 7 - J UL I,
13 X a > LL X- . X C :■ ii D X X
' X X LL Z Z □ J L 1 I D U I _J l= “•
LL LL
^ ~ X 1 X
•=.-—** if. ‘.if tj. X 1—1 •—
•7 L X X X X X X X X
•x* co Co co 10 co co co co co
L XXX
"J " £• >7 'I P n - t 1 ■ 1
L=U L^4 I—I L_
CO CO 01’ CO CO CO CO Co LO CO CC- CO 1
- '‘*J ll ' L 1 '7 -
1 X X‘ UJ X X X
I.I.- M > 0 I I - M .
X X 1=4 OJ rt t - X 1=4 X
UIXXXXXXXX XX
CC CO CO CO CC* CO CO 0.* CO CO CO
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 29
411
DATA-BOY m
SPEECH PROCESSOR
BY JAMES ANDERSON
Copyright 1978
Mimic Electronics
P. O. Box 921
Acton, MA 01720
The Data-Boy™ speech processor is essentially a speech
“digitizer” which uses a proprietary signal processing tech¬
nique to convert the human voice into a single bit data stream,
and vice versa. “Digitized” speech is typically thought of as
speech which has been sampled with an analog-to-digital
(A/D) converter, stored in digital memory or transmitted in
digital form, and then re-converted to analog form by a
digital-to-analog (D/A) converter. By using certain char¬
acteristics of the speech waveform, especially the fact that the
amplitude components tend to decrease with increasing fre¬
quency, the resolution of the A/D and D/A converters re¬
quired can be decreased from, say, 8 bits down to a single bit
while maintaining intelligibility. When this bit stream is
sampled at a rate of 8000 samples per second, highly intel¬
ligible speech can be obtained. The speech quality is close to
that which is given by a CB radio. At this low data rate (8000
bits per second), the sixteen hexadecimal digits, “zero”
through “F”, can be spoken from the data stored in only 8000
bytes of memory.
Speech digitization has several advantages over other
methods of speech production. First of all, the hardware
required is fairly simple and can easily be mass-produced,
thus lowering the initial cost to the user. Secondly, the soft¬
ware cost is small. Simple programs for sampling, storing, and
playing back the speech data can be written with little effort.
Also, the cost of adding a new word to an existing vocabu¬
lary is minimal. Finally, the system gives “natural-sounding”
speech (especially when whole phrases are recorded and played
back) because the speech was originally produced by a human.
A one-bit speech representation has several advantages over
other speech digitization methods, aside from the obvious
reduction in the number of I/O lines. The speech can be stored
in very slow memory (100 microsecond access time or less)
and a few random bit failures in the memory will not signifi¬
cantly affect speech quality, as the speech data itself is highly
redundant. Thus defective RAMs and ROMs can be used, and
these are available at very low prices... so don’t base the
cost of a speech storage memory on what you’re used to pay¬
ing for computer-grade chips'. Note that this use of defective
memory is not recommended for use with, say, 8-bit A/D
conversion speech digitizers as bit failures in the MSBs tend
to give rather annoying “pops” in the speech playback.
Another interesting aspect of the one-bit representation
of speech is that it is very easy to do digital signal processing
with such data. The Discrete Fourier Transform (DFT) can run
in less time than it takes the Fast Fourier Transform to run—
and with a much simpler program. The reason for this is that
when the time domain data is always a “zero” or a “one,”
all of the complex multiplications in the DFT turn into addi¬
tions. Thus it may be possible to do automatic word recogni¬
tion on a limited vocabulary in something approaching real¬
time operation.
The Data-Boy™ speech processor system provides a
low-cost, easy to use, reliable method of speech production.
In fact, this method of speech production is the lowest cost
of any method available where limited vocabularies are con¬
cerned. New uses for computer speech output, such as video
games, aids for the handicapped, and perhaps even talking
appliances, may result.
Interfacing the Data-Boy™
The speech processor can be interfaced to just about any
serial or parallel I/O port on a computer, as long as the port
uses TTL-compatible signals. Any bit which can be changed
rapidly under computer control can be used to produce
speech! As a last resort, it is possible to interface the Data-
Boy™ to a computer through the computer’s A/D and D/A
converters, as long as the TTL conventions for signal levels
are observed (this is applicable to large computer installations
where user access to I/O ports is not available).
300-/V
Simple Configuration for Recording and Playback
Figure 1 shows a simple configuration for the recording
and playback of speech. The power supply, microphone, and
speaker should be connected, but are not shown. An optional
Light Emitting Diode (LED) is shown, which gives a visual
indication to the user when the SQ UELCH threshold has been
exceeded and data is present on the TO COMPUTER line.
Page 30
412
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
The recording process is initiated when the user notifies
the computer that he or she is ready to record (via a RUN
switch or keyboard input, for example). The user then speaks
into the microphone while the computer samples the data on
the TO COMPUTER line. The computer stores these bits (the
speech data samples) in memory until a fixed length buffer
is filled. At s ome future time, th e computer puts the data
bits onto the FROM COMPUTER line at the same rate at
which they were originally sampled, and intelligible speech
results at the speaker. Phonemes, words, or entire phrases can
be stored and reproduced in this manner. NOTE: If phrases
are stored (continuous speech), a certain amount of static
(noise) may be heard between the individual words of the
phrase. This can be eliminated by editing the data so that
only the valid speech remains (set all the other bits to zero),
or by simply recording the words one at a time and then out-
putting them in succession to form the phrase.
Sophisticated Configuration for Recording and
Playback
Figure 2 shows a more sophisticated configuration for the
recording and playback of speech. The power supply, micro¬
phone, and speaker should be connected, but are not shown.
Input Program
In this configuration, a user speaks into the microphone,
thereby automatically in itiating the recording process. As long
as the DATA READY sig nal is active (low ), the computer
samples the state of the TO COMP UTER line and stores
these speech data bits in memory. The DATA READY signal
line can be connected as an “interrupt” signal to the com-
PATA - C co^paTfr.
Sffrcff f/tic csset.
Figure 2
puter, if desired, or it can simply be sampled periodically to
see if it is active. Speech output is handled in the same manner
as before (see section E). A flowchart for a computer program
which utilizes the configuration of Figure 2, and which makes
efficient use of computer memory space, is presented in Fig.
3.
Output Program
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 31
413
If only half-duplex operation is required, the speaker can
“double” as a microphone. Speech quality may degrade some¬
what, depending on choice of speaker. The microphone input
leads should be terminated (preferably shorted) when not in
use, to prevent spurious signals from triggering the DATA
READY line. One possible configuration is shown:
If higher power output to the speaker or external volume
control is desired, an additional power amplifier can be used.
Speech Storage Space vs. Intelligibility.
A common method for evaluating speech intelligibility
is the “articulation test.” Typically, a person reads a list of
syllables or unrelated words to an “untrained” group of lis¬
teners (recognition ability improves with practice) and the
percentage of items identified correctly is taken as the arti¬
culation score. By choosing test material representative of the
sound statistics of a language, a realistic test of the system can
be made. Word articulation scores for speech which has been
processed by the Data-Boy™ input circuit, sampled at a 10
KHz. rate, and played back through the output circuit are in
the neighborhood of 90% for trained listeners. When words
are used in sentences, contextual information is present which
leads to considerably higher articulation scores. To test your
system, try recording the sentences “Joe took father’s shoe
bench out,” and “She was waiting at my lawn.” Together,
these sentences contain most of the sounds in the English
language.
For a fixed memory size, the amount of speech which can
be stored is inversely proportional to the sampling rate. For
example, if one spoken word can be stored in 5000 bits of
memory with a 10 KHz. sampling rate, then two spoken words
(each of the same duration as the original spoken word)
can be stored in the same memory with a 5 KHz sampling
rate. Thus it pays memory-wise to have the lowest sampling
rate possible. However, there is a trade-off in intelligibility.
To minimize this trade-off, the following two methods of
speech recording are recommended.
1. Words containing mostly low frequencies (eg., “one”)
can be recorded with a much lower sampling rate than
words containing mostly high frequencies (eg., “fix”).
Simply store the sampling rate which was used to record
the word, and use that same rate to output the data for
playback.
2. The effective amount of storage required can be reduced
somewhat by using phoneme concatenation. For example,
the spoken word “seven” can be stored as an “s” sound
followed by an “eh-vun” sound. The same “s” sound can
also be used in other words such as “six,” “s” plus “ick”
plus “s,” without having to re-record it. Similarly, one
recording of the word “teen” will allow you to generate
“seventeen” with a simple program which outputs “s”
plus “eh-vun” plus “teen.” The method is quite limited
with this hardware, however, and in general will not pro¬
duce acceptable speech. For example, when the spoken
word “dog” is broken up into “duh” plus “aw” plus
“guh,” the resulting audio does not sound like the intended
word. This is due to the fact that in natural sounding
speech, the end of one phoneme often blends into the start
of the next (but not always, as was shown in “seventeen”).
If all of the phonemes are recorded separately, some
method is needed to blend them together—a formidable
task indeed for this method of speech production.
Other methods, such as encoding the bit stream, are pos¬
sible but may prove difficult to program or result in little
memory savings by comparison. Note that the two methods
cited above apply to the recording of discrete spoken words.
A reasonable vocabulary can be stored on a standard
floppy disk: 240,000 bytes can contain 240 seconds of con¬
tinuous speech (or about 480 discrete spoken words) if an 8
KHz sampling rate is used. Alternatively, a cheap semicon¬
ductor RAM or ROM system can be built to any size, using
slow and defective chips (with random bit errors). A few ran¬
dom bit failures will not significantly affect speech quality,
as the speech data itself is highly redundant. However, bit
failures of a periodic nature (eg., every eighth bit set to a
logical “one”) will tend to introduce undesirable “notes”
or “tones” into the reproduced speech. In any case, it is more
cost-effective to use an inexpensive “speech storage” peri¬
pheral mass memory rather than expensive computer main
memory for vocabularies of more than 20 words or so.
Intelligibility of speech produced by the Data-Boy™
speech processor can generally be described according to the
sampling rate used. A 5 KHz. rate gives marginally intelligible
recorded phrases. An 8 to 10 KHz. rate gives highly intelli¬
gible single words or sounds and extremely intelligible phrases.
Sampling rates greater than 15 KHz. merely waste memory
space while offering no appreciable improvement in speech
quality.
414
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
x
X
N
X
z
CO
z
z
o
X
z
H x
x e-
»-
X
3 H-
X X
<i
h-
x cn
X
K
cn
X
cn
i- >-
h- <r >-
X
X
>-
3 cn
>
•H »H X
X
Z h-
X
cn
o
X
X X
h-
u >-
X X
o
X
Z
h- X
O X
o
X K
<r
<L O K
PH
M
o z
r-
X
H- t- PH
O
X 3
x <r
o z
<i
<L Z 3
X
X
cn
Z
X
X
X »-l
p"
H- X
>-
X
Z 3
X
X X
X
<1 X
3
X H-
h-
i- z cn
3 z cn
cn h-
X z
h-
3 X
X
X
X 3 O X
o o X
X X
X <c
X
H- X
X
CD
CD X X >-
z x >-
X CD
X z
X
z
o
X
X
3
X
X
X
PH
X
1-
cn
X
V—
•z
X
o
►—
X
z
>-
z
z
X
o
o
<r
so
3
X
u —
■x
X X
X
u
<T
X X
u
X
X
X
h-
( -
X
x
h-
<L
z
X
3 X Z
z
c
h-
X
X o
X
z
z
v-t
c
z
o
o
T-*
o
x
3
*—i
3
cn
X - X
X
PH
PH
XI
3 ►—
CD
H-t
K.
X
PH
i
c
o
GO
CD
X
X
'C
o
X
z
>-
♦ OH
t—
X
X
X
x cn
*
X
o
I-
*-
X
z
-tft
4*
**
H H CD tfv
X
f—
<i <r
<1
<E
<1
<r
<x
<1
X
X X
X
<r <i
X
X
u
X
X X cs
<1
<1
c
<E
CJ
X
<r
X
3
3
3 3
X
X
X
X
3
X
X X
cn
J z
o
X
X h-
cn
o
X
z
Z X
X
X
»-
X
i-
X
X z
X
z
5
c
c c
z
z
CJ
X
C5
Z X
CJ 3
X
X
x cn
<E
X
X
X
H4 CJ
X
X
cn
X
cn
X
X
X
X
3
X
X
X X
X X
X
X
X
X u
CJ
CJ
X X
X
Q
X
X
X
O
X
X o
z
X
z
X
X
H-
c
cn
X
c
X
X
X K
u
X
X
X
X
X
3
►—
o
X
o
<x
<1
1 - z
X
z
z
X X
3
3
o
X
x
1—i
KH
3 O
t—t
X
3
D
a
# *
* o
* X
*■
*
* X
*
* cn
* X
X
o z
* X
X
►“
X
X
cn
<r 3
o
in
in
<r
<r
fS
<T
bn
S)
n
X
co
X
1
X
H X
CD
CD
CD
H
00
CO
00
GO
on
X
X
X
r*
o o
O
_
o
o
cn
00
_
c
»H
H
Q
X
o
<1
X
X
<r
X
CD X
o
o o
o
CD
o
o
o
o
o
o
o
X
X
X
N
X
X X
X
rs
CD
>0
<1
>0
00 CJ
IS
SO
rs
SO
IS
>0
c
S3
o
X
CO
X
o
X
o
X
IV IS
u
<1 X
rs
rs
IS
n
O X
cn
00
X
<r
X
X
<r
n
CJ
IS
c
X
X
O 1*5
>0
O- X
X
<r
rs
Cb <z
x
X
_
<r
>0
o-
u
X
X
»H
■0
<r
bn
<3
rs
co¬
z
<T
on bn
U0
un bn
bn so
so
>0
<1 >0
o
>0
rs
IS
IS
rs
rs
IS
rs
CO
y-f
U-4 X
00
CD
CO
CO
co
cn
H
eH sH
tH
tH y-i
tH
tH
*H
H
tH TH
sH
tH
y-i
*H
T-1
T*
«H
H
tH
y~i
o
o
*H o
sH
H
o
o o
o
o o
o
o
o
o
o o
o
o
o
o
c
o
c o
o
o
CO
CO
X X
o
o
c
o
o
X a
<1 z
IX c
CD
O X
X H-
x >-
u x
PH
o x
3 X
<1
UJ 3
iX X
O X
t- <1
CO X
UJ »H *H
X o o
X CD N CO
<x
X H- h- H-
CD <E h <1
A
X y UJ
X H o
05
05
X <1 3 X
I X I
uj <i k- <r
XhDw
<1 X O X
3
05 05
X X U
O 05 05
05 X 3
<1
X
x
x
X
X
p~
X
<T
cn
X
X
X
o
x
X
X
X
cr.
X
cn
X
X
z
X X
>-
x
x
X
X
3
Q
HH
X
X
z
X
o
X
a
X
X z
X
CJ
X
c
X
X
X
PH
X
z
a
X
3
X
c
X
t-1
Q
cn
z
X
x
•
X X
a
X
x
cn
o
3
z
<Z PH
3
x
X
u
X
p-
1—1
X X
c-
X
X
<1
X
Z
CD
X
X X
X
<1
X
X
X
z
X
X
X
X *—
z cn
3 z cr
cn
■— 1
X
X
g
X
X
X 3
o X
C 3 X
X
X
<T
cn
CJ
X
*
X
CD X
X X
Z X X
X
X
►H O
X o
<t
ph X
UJ
X
XXXX X X 3 X
Z X
UJ <T
X UJ
►“ XX
Z XX
CJ xx
K X K 3
XX X * X * o *
3
X CD
Z X
PH O
* * * * * *
N
X
<x
z
PH
*
x x
X X
X X
ZXXX<I<E<TXXXXX
OXXXXHS-XXZXZ
cjucjcjxcocnxcjHrjiXi
X
-I
X <T <E <1 X X
X X !- Q 05 X
X X X X 3 X
X
05
X
X
<r
x
cj
o
3
X
o
05
-* *
z
X £J
<1 X X
z
x :
x x u :
cn o x :
xxx.
X X
Z X
CD ph
*■ X
<E C
R S -
X X 0j
X
X
z
<1 u
X X
0-
rs
V
o
so
<r
IS
<r
S5
3
CO
CO
X
CD
CO
CD
CO
CD
o
o
o
H
re
n
«r
rH
m
r4
o
— ,
00
o
CD
TH CN
▼H
H
o
o
tH X
CO
CD
o
o
o
o
o
c
o
o c
o
o
X
CD
o
C <r
X
o
CD
o
o o
c
o
o
o
O
X
X
n
X
X
X
-0
IS
fS
X
u.
X CJ
so
X
SO
is >o
X
X
<r
0-
<X S5
CJ
CJ
•<o
f> N
■0
<z
u
so
•o
so
-0
so
CO
<1
<r
o
so
O X
CN
IS
00
X 00
X
L)
IS
so
rx r-j
c
X
r-j
CD
X
X
<r
o
o
1*5
bn
fx
0-
X
X
X
3
-0
CO 0-
ft
X
tH
n so
CO
X
X
H
rn so
X
o
CJ
X
o
3
so
o
CO o
o
o
c
o
o
o
■»H
H
y~*
•rH H
1H
tH
r-j
CN CN
CJ
r-j
C l
m
3 3
3
3
3
3
<r
H
H
H
▼H
-H
P-1
tH
»H
y~<
»H »H
»H
Y-t
•»H
H tH
T-l
H
y-t
tH
y!+
H
o
o
o
o
o
o
o
o
o
O
o
o
o o
O
o
o
o o
o
o
o
O
o o
o
o
o
o
o
o
o
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 33
415
0147 26 FU EINr- *-i MAKE SAMPLE RATE 8 KHZ BITCNT 0134 BUFEND 0187 BUFFER 0189 CLEAR 0116
* BELA i 0143 DELAY2 0179 DONE 014B LOOPI 012E
0149 20 E3 BRA LOOPI CONTINUE L00P0 015E M0NT0R E0E3 0UTEEE E1D1 OUTS 0156
* PI A 8014 PI AB 8016 QUIT 0153 STOP 0181
014B 86 45 DONE LDA A t'E ‘END - PROMPT TEMP 0185 TIMER 0186
Whatis:
An Expression Evaluator for the 8080
BY MIKE GABRIELSON
Box 2692
Stanford, Calif. 94305
Programmers often need to manually verify the results
obtained by a computer, especially while sitting at a console
and debugging code. Pocket calculators with capabilities like
hex or octal readouts and Boolean functions are a conven¬
ient tool, but ignore the fact that the computer itself can
operate as a handy desk calculator.
Whatis
Whatis is a program for the 8080 that can evaluate arbi¬
trary arithmetic and logical expressions, such as:
5 * (3 - (6 * 2)) < = ( # FFE / 2)
Whatis operates as a subroutine. It accepts the address of an
ASCII string that contains the expression to be evaluated.
The end of the expression string is marked by a character
called EOS. In the accompanying listing, EOS is equated to
zero. Whatis will evaluate any string and return the expres¬
sion’s value in the HL register pair. If the result of an expres¬
sion is a string, the value returned in HL is the address of the
string. However, if a fatal error (such as division by zero)
occurs, Whatis will load the address of an error message
string into HL and then call an external routine named
SABORT. Whatis does not expect SABORT to return control.
Whatis Input
Whatis breaks the expression string into a sequence of logi¬
cal syntactic elements called tokens, which are special se¬
quences of adjacent characters. A token is either an operator
or a constant.
Operators
Operators are used in conjunction with constants to form
expressions. The operators are:
6 dyadic and
* dyadic multiply
+ dyadic add or monadic plus
- dyadic subtract or monadic negate (two’s comple¬
ment)
/ dyadic divide
II dyadic remainder
< dyadic less than
> dyadic greater than
<= dyadic less than or equal
= = dyadic equal
>= dyadic greater than or equal
« dyadic or monadic rotate left
» dyadic or monadic rotate right
I dyadic inclusive or
II dyadic exclusive or
~ monadic one’s complement
~= dyadic not equal
Constants
Constants occur in one of two forms: numbers or strings.
Numbers represent values for use in expressions, and can be
represented in decimal or hexadecimal. A decimal number is
a sequence of decimal digits. A hexadecimal number is a se¬
quence of hexadecimal digits prefixed by a pound sign ( #) or
enclosed in single quotes and prefixed by an X. All numbers
are evaluated with 16 bits of precision, and overflow is ignored,
so that numbers are limited to the range 0 to 65535 decimal
(0 to #FFFF hexadecimal).
Examples: 1234
X’ face’ (64206 decimal)
#32B (811 decimal)
99999 (evaluates to 34463 decimal because
of overflow)
Strings are any sequence of characters enclosed in single
quotes. Each character represents the corresponding seven
bit ASCII code, with a high order eighth bit of zero. Two
consecutive single quotes are required to represent one single
quote within a string. Null strings are ignored.
Examples: ‘Pack My Box With Five Dozen Liquor Jugs’
TJSERS”S MANUAL’
Expressions
An expression has the form:
{|operadl}operator} operand2
where “operator” is one of the monadic or dyadic operators,
and “operandl” and “operand2” are constants or expressions.
The brackets j } denote optional items. Dyadic operators
require both operands, monadic operators require only
“operand2.”
All operators are of equal precedence, and expressions
are evaluated from left to right. Parentheses around an expres¬
sion may be used to alter precedence; the innermost expres¬
sion in parentheses is evaluated first. Expressions are evaluated
to 16 bits of precision with no check for overflow. All arith¬
metic operations are performed using unsigned two’s com¬
plement arithmetic.
Page 34
416
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
Examples: 3 Evaluates to: 3
((3)) 3
-(+3) #FFFD
~3 #FFFC
1000*1000 16960
#FF & 300 #2C
16//6 4
1+2*3 9
1 + (2*3) 7
(#2B - (7 I 12)) +(5 I I 13) 36
Relational Operators
The dyadic operators
= = ~= <=<>=>
are used to form expressions that evaluate either to zero or
to one. All relational operators perform an unsigned magni¬
tude comparison. If the relation is true, the operators produce
a result of one. A false comparison results in zero.
Examples: 5 == 5 Evaluates to: 1
3 + (2 ~= 6) 4
(1 <= 2) <= 3 1
#FFFF <0 0
The operators
« »
can be used as dyadic or monadic operators to rotate (not
shift) 16 bit operands. Rotation implies wraparound of bits.
Shifting can be accomplished with the multiply and divide
operators. When used as monadic operators, operands are
rotated one bit. When used as dyadic operators, the first
operand specifies the number of bits to rotate.
Examples: << 2 Evaluates to: 4
» 3 #8001
> > ( < < 2 ) 2
3 > > #f0 # IE
String Operations
If a string constant appears in an expression with oper¬
ators, the value of the string is the ASCII code of the string’s
first character. An exception to this rule occurs when two
strings appear with a relational operator: then a character by
character comparison of the two strings is performed, using
the ASCII code to determine relative order. If the two strings
are of unequal length, the shorter is padded on the right with
blanks.
Examples: ‘A’ + 1 Evaluates to: #42
‘ABC’ & #ff #41
‘CAT’ < ‘dog’ 1
‘PAD’ == ‘PAD ’ 1
‘123’== #31 1
Final Notes
The Whatis program listing was generated by a one-pass
assembler. As a result, all forward references show up as
question marks in the object code field.
Provided with the necessary input, output, and error hand¬
ling, Whatis can be a useful addition to a programmer’s toolbox.
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 35
417
5
>• O — X V
IflZ O Q
=> < to h h
O - C Z
-■ u x a: os
> i< H W U 3
uu cxt-
x x o 3 O x
o. t- w a
H CO • CO 1/3 »
u 4 o ul ui O
O 3 Z >« X Z
Q -E-* CO *
30U1I/IU0
- Z O •- X z
JXQaUIIUCKUJ-tQXQQ
OEXICCC
X X c c c u
x ;d z x z *
SI Q D J D <
zuzkzsu a o
ZKU4U<31i.UlflZX
OOZQ-Xq,hOXXhH
c'li.4J4aiLU£4«U)
u u a ia. io in |H |
OCQ.JXXXXXZXCOX
O.Q.XO
3 a o ||
co H ' co o
cu a, a. x c
X O O X IX J
£ < ix o 3 x <
» X O O I CO CO >
XXQOZXCJZXX X X to
OX J
xco>*-j>>x>«x>m>>ffl>oQe-
*OO0>C0000>Z0O00ta0ZCX
3xxs:z:uxxxs:z:>-z:tnxxcoxr>ox
< - - > H
•• QXNXUOIO
co jonunxx
CHXc-lXc'3XC'lXc'JXt'
ycouououoOTU'-
CO J m J x > M _J X X J X
DXX<NUOXN<I OCX
xjju’^qzo'-ju'-s xun
X O X X X o
cj O O w M o
U O u
o -J to CO
3 Z O Q Z
H X O O O x
X E- O O X
CO O
H X z Z 6-
X XXX
OE-HxxH
XZUOOZ
x C H E-* x
O X X X
< X C 3 3 X
X Z3 X X X 3
= U O Z Z U
X E- O O
X O Z Z CO
O X C C H
X X
X X e* Q —•
x > to z f-
H > O CO '
X C Z X O
'JlAXXZ
CO 0) z
O CN
C CO Q X Q Z
x a c
to x x J a h
3 XU X O X
x j a to x x
1 . > x > x - E- X«CJ«E
CcjOZOSTnXX £ > Z X L
Jnzr — zurjxx u z: n -> •
> x n > x e-*
O £ Z O £ X
£ U X £ U X
"UHUf
I •• •• X Z X £ U
10 CO O X U CJ 0
3t*Z
■« X X ••
Page 36
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
2
10 u < u a. u ui
uz a. z x o- z (\.
06 3 O H 3 to 3 E-U
<x* to h to x to u to mq
' Q to to *XXX ‘ O to to ' X to to -tj >
OZ<UOU.<UOhi<UO>-<<UOi-iO<
z<~->«z3K>.zx~»zH-'>-zaz2
a u
u M
H a,
U M
2S
< 3
I
u
H
U X
z u
M J
KUhE
Q > X H
Q < id to
< x z
a.
H Q H U
tO Z CO CO
O < o x
as s x
6 U O H <C
iHEEE
O X z
DHh
o •-> a
x h
o to
z to
s -« H H
Q O to
Z 3 <
to a 3
J to <
C HZ
U 06 O U
<03
j a o to
z to H co u.
3 H O 3 a
0 3 C
: * 3 oto c
- to O 3 <
CO
*>*oifl »e-
5 < » to o a
£ z h x z c
0.22
O < O
z * z
tflUOH
to z ex
to x H H
EZEtn
O < H
Q to Q
3 Q X Z 3 >
C O H Z
O H
- E- to to - to
d z co x o to
3 « X < Z >*
O Z O
Co O O
*-> u
to to
co as e-
Q to U
O > CO
CO Q u
>6 <
O X H
H Q O
to to
co at as
Quo
O > E-
u o2
Z M CO
to a a.
x < O
°s*
H Q to
to z x
o < o
H .
H as u
O to
a tu to
who to »
X to O to CO o
H O 3 <-> >* Z
H Q CO
to z to
o < to
to* a* o
*<s < <j> co
<* z* a
H H 3
MU' to SC
H H' HU
CO CO* to <
O O' O CO 3
£ x <
* * >.
QUO
« a
5? 22
z > a
to •-• <
OS Q CO
3 0><
Q CO tO
- ' x a
l&isssislsi
> M W
d O a. > f
CIUZC
> M l-t
0X00.0
z o n o n
J»J>Xk
X 3 < o z X f.
3 X U Z ►
3 X X X X 3 ME
*»<0>000<0>u
-sooxa«ao'->xo
"H Jh
> > < to
Z X O 06
"H J(-
> > < CO
X Z O X
►H W 3 H
:> > < to
JCZUE
o *n oj vo < o
n r- < a m a
D S SMS S S S
< < to < r~ i
Htsns m i
to to a co co h a
M ® o X o in o
O *
E-* x
< H
06 Z
CO *-
X O
O x a
< as
to O
to H
O as
co O
x e-
to >*
06 U X
q x o h
to x o < '
x z a H — x a
QUEEtO' to O
Q U X < CO X
< x O 3 E- x
O » M
E- < to «H ' to
coE-coOtotOOco
OtOB-ZOMZB-
O to >• Z
H to S- to <
< to x > as
X 06 Z HU
u a u < x
X Q X O
OCX 3
o u
H H < H >
u u H O u <
o o to z u to
Q tfl >• tfl o
Z to H to z
< U X u »
X x x as to
CO Q U Q to
X Q Q m
O < x < x
o
H H < H -
to CO H to O
O C3 X O Z
< J X
os x O *-•
CO u x H
£ fe g
O u u
X z H Z
z
H H M OS
U U O O
O 3 X X
c to o to
a to 3 u c
Q X O X 2
X H X 3 <
O X X X X
x x O | as
OH « ti- ~
«< XX «< -H H
XHXUOZ E- OS 3 o x
O X X X X < xxxtoo
X X o |XX3 ZO ICO 3
OH - CO o O to < - 3 - < to
XXOQUXXXXQOXVrXX
H H X H
X X X X
X X H X 3
X X 3 X x X <
»X ' X * X >
< X < X < X u
« <
X X
X <
U X
X CJ
X
Sfe
C U < X o X
O HZ
X X 3
tu M Z
o u X M
H X
z u u
e to X 3
X Q 3
u O Q <
X ' <' 3' 3'
g. 3. 3. 3„S
S- v 3.-'2. >
33m3c-J3XX3m3mnXXE
<XX<Z<33XX<XZOOC
U33UOUXX33CJ3UXXC
X ••
O Cu
X O
> 3 > 3 m 3 X
O < o < >< z
Z U Z U Z U 3
o ••
X
1 £
I 22
I U U I
I O X I
x a a
X 3 > X 3 X E
3 X o z X O Ci
X 3 JT •- X X Q
3 > M M m M
jinunuTu^UTU 1 -
BOt-jUt-SUZO
nt'4QS5M-
1 U fd o u X t.
3 si m vo av < c
U U
O O U t_) X o
to cn r*- cm cm to cj o ^
.M"l\Ct'®UlUQQQQQQQQ3
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 37
419
O CO
X X
S 3E
< J :c
Eh X W
IS) 10
z 3 x
4 t3
X EH o
O X •!
tO W -
CO X tO CD
— 4 Z> O
II to
C 4 X
O E-'
co O s
Q Z '
' 6 -.'
«j O "
• 2'
W »HW •
n to o to to o
to to Z £
: in x is) x to
in E'¬
en
to to o
t to a h to
t-1 i JL.
QJIHOlOO
«- < 4 E- Z X Eh
-• a >• < t- <
» to E-* Z E- X X
n * > — a. to a to
0Q<ZOZfl.ZH
X X Z X 4 X 4 X
X E- 3E X X Eh X E-
to h a.DO a-atca
z in U' — -h a x o z o x
* ox z to»to-«c»E-«
<£ X to <> — xo4inxxxx
O x
in o
x a
O E-*
o a
X < to
vo z to
— ox
Z O
Z 4 X
4 X O
XX x a z
JtflXIfl
Z' o«
Q H
to Z Eh tn
to x to to
X X o o
O E- X X
< <
O £3 > >
*H Z
x < in in
to X* '
x to a a
o x z z
z o 4 4
x a
Eh U X tO
— — X X
Eh > H
CO < to to
uinua
in x <
O 2
X Eh x
0 4 3
X X O to ti
o4uo:
Z Z X v
O Eh X
3 - X
H Z O
4 X X
XXX
X EH EH
u X z
D O X —
> O
h a 4 x
n z x
Eh — X rH *
SSF.
o x o o in in x
— O — OO—OE-
XZXXZOEhX
uxuuxtninx
x x — 4 — J — X E
JOX>t-XxXxtj
iQwxmjinowQ
5W3WS
vo < m a- — a <•
nvOO'XOaQXB
n ov x u x x a
* u o o o o c
rtriminifitnintrtt/
nmmmmmmmir
CO 00 CO 03 CD CE
'iflMOO'SHNI'l^inifiMOWSHNn^l/'IOMOO'
-iinmu->ir>voiovOvovovovO'«ioior''f'-r'r»r'-r-rHr~rHr~
o vo vo vo vo
O x X x ii
a X X o
z v 4 x x E- z
x x x Eh 4 a
SC X X Eh X Eh 4
0 0 4 a x x x
Eh X Eh O - X
x — * 4
e- a o in * x
xzocnxoxtn
(34JHXZU1H
Q X
4 >
Z Eh
4 X
Z O
O X
Q X X O
Z 4 X X Eh Z
X X X Eh 4 Q
X X Eh X Eh 4
O 4 O X X X
Eh /s Eh O m X
X - • 4
Eh Q O X * X
xzocnxoxtn
04XMXZX—
5 H Eh
x n-
Z O'
Eh >.
X X
O 4
in Eh
4-0
x O x
. 5< Eh
D > X X O Eh
3 4 O X O X O
x x x a o x Eh
' a a o >
0 O 4 EH o z a
JZZOUOOO
-4 — 00404
IS) o
Z X
O X
U X
XX X
fc» Eh X X
Eh O > Q
X O 4 Q
X OX 4
X 4 X H
X 3 X
E- Eh O
H X Eh
3 I X
* 4 O
OX*
5°S
u O' Z
0£^<®
XXX
O Z Eh
> Eh in X
I) X a
j o x >
h z o a
X o
E- Z
4
X Eh
4 -
X O
X Eh 4
X X X U4 *. UJ
» -XX I *
O Q 4 X X O
‘.S
X —
x a
x 4
>><XcvJ>><X
rzoonrrox
o a 6- x « a
•H EH 4 X o x II 4
X O X O X O' X
0042x0X4
IS) X
E- X
X z
4 O
— Z
O X
- o
O Eh
a o
4 Q
< ® E 1 U E 1 XX '
6 ».xxo ' * e
xxoozxaxxxov
a £ a
X X i_
H> — XXOQ>>QQQ-i-
30>44Z4004440<
'jrzoooorzooQxi.
x - Eh
4 > x
OCX
T. VO Eh
O O x
S IS) O
X. X
O pH Eh
-OX
•> 9 52 g .
3 X — O
I4XZ
> O X • -
> — _
Hi
E 4 X
5 Q £
I X X X X 4 Z
J Q a Q Q X X
i 4 4 4 4 4 Z
? o a o o o n
a a a
x x o
Eh H SC
4 X' O' O O
* * X O X O 4
004' O' OX
X>> —
O O O X f
X Z Z O i-
OxXXXXXXXti
rinvo rv eo a> ® -
HiNn»uii«r't0 9iSH(vn»i/
-iiovnininininininvovovovovovi
'ininininmi/iininitMnu'ininu
'in^UlvOMOO'SHN
'r'l'M'i'M'inco®
runinininininu'ininm
Page 38
420
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
ur
uJ I h
a. \ -J
° \ 3
O Q
i X
E-* ll
.. x
£h 01
hZOi/1 *
CO O U ul O
& a ~>- z
S o —
Z (V
u >-h o
x h x
O < ui
CO 3
S-ZOM '
uouuo
O Q '— >• Z
Z J
2*
O Q
f.
ul S Q X IX
- » * | a. to
u x < co x eo a a.
a > co u x
O -• * * oi
x a x j a
<n x x
a. > x
O — <A
a. q
O *
a. < a
a < x a x x
a. o xx
O * |-
x < co x <
£-* <
o a:
< xx
* ioi
x o x a
x q < co < x
O - ' * *ui
x<xx<-j.jx
X Q < U1 < X
O * » » «01
X<XX<J.JX
x a < to <
O *
X < X X < J uJ
>M>< Q X X J Eh
OXO«N<UI<U
ZJXOnQQ'->OX
_J J _l l— V J > < > U > J > > J > X X J Eh
< < < uJ v <0XN0<0<00<0UX<UJ
UUUX UXO»-jXXXXXXXXQnUX
J>< > X > X > > X > x X J EH
<0XN0<0<00<0UX<U
uxorjxxxxxxxxonux
J><>X>JEh
J><>>4>JH
<oxooxo<uj
uxoxxoxux
J > < > > < >
Q<m<oXQXXUXi~xmOo%
Q <
u X X X X Q
auOSH(vn«fuiieM8(jiui>.os5
■MOr-a]»®H(Nn<ri/
H U u u
n'»rir>eoo\<muatiJX®'M^'r-cocs>®oo
'KN(NNN(NNNNNNninnPinf | innnnn'nn
SQlS®SSISlSOSISEllSISSISOISOISS m "’ m
, 'Co<7'®^H<NroHrinvorHwai®<HrMn>»invor~
Q < ■» f- c
UMSior
UQuJU.<S'-i->Tini/-iinincDCTN<c
O < t.
IX JllOMOffl C
u h w C' (Q Q U
U < vo r~ < o
•*■ ao O' <
O IO to ifi
s fa ® si
n n x in
O Q
z z
-I <
X X
H UJ
C/1 X
c o z oi z
x x z x z ;
* -J 6- >
• <oif
> —
j a
» o x :
C Z O *1
1 < X U
- r- hi X
•MQOI
* O X
U O
1 N
. E- E-
tuum
1 Q O -
in - Eh w u
U O UJ o hi X
X Z O Z >* U
< UJ
X
o <
z
< X
X Eh
UJ O
° 2
X X
UJ z>
2£S
Cl] o u
89*
c.
EH eh *
UUE
O O 0
> >
< o
01 X
Eh O] Eh
< aJ X
XXX
ui a id
x a
O < x
xxx x
O U O H
< x z
01 Eh o O) X CO
01 01 Eh 01 X u
UJ < Ul Eh J UJ
x s x x z a x
Q Id Id □ h < a
O Z X Q o EH <
< O < X Eh
co O
e- > Eh Eh Eh H Eh
I d < Id Id Id Z Id
OOIOUO-U
01 01 01
a o
z z z
22°
E- O O)
Id Q D
U < X
< m o u <
coy<oy>ZNX>zo>o
jxRux5<j:u’-iuxxxxq
I 1 h I h Eh
/ o > y > to
tKsx
SHSs
Z X
I < =>
I X EH
a x a
-H Eh
O X
oi o
Q Q CO X < X b
els
CO X
X Eh I
O 01
O CO
E X
P* Eh I :
58 i;
<<Nyoy5uoxuOu
au'-jQXQiaxojxxo
X < X «r H
E- X -d £ CJ X
axiidoio
X O If-ZO
X EH JO
Eh XXX
X O < <
X £ X a Q £ £
Eh ' * a a »
1X<X<<UJXO
JQ JE-
< < < Cd
u a u x
o a
a a
< <
x uj < o < x
O » » - * 01
x<jj<xxx
)ooo<no<u]
: 01 £ £ O) £ U X
ot co in id to id id ui
OUldiOlNIdnU
»iciifi«(j«0'Oiin<iliUQtdSiNni'
«l CO Q u <N u
OCT'<H5c_IUXf'
ruo P* CD l]t Q r-
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 39
421
:u)qu.
' O — XL
Z bi E-E-
<QQ>>-
as o z to cd
bl U <
CL CC HQ
bl bl to bl
I I H I u t
QHhHI"
fiOMJa-aa
to ce i/i
Q. O W) ('•
OHUJ
S X J
Q =>
IUQO.
H a. <
O —x
u o
> E- E- < u
<UlalHU
in o e> w >
Q Q
< «
» >•
\ Q Q -«-
a a
< <
z z
ll il o o
' A . £ £ I
HUD £■
0. CL X Cl. C
l z O iz CD ;
* < *bl < - «;
1 CC Q Q a Z I 3
bl ul
z a.
O O
Z-iXXJXSX
-W1 * Ul * V) W U1
< a. < a. < a a. a
-ui>j>4a.JH
uu < x o IE- c
> j ►- .j >xje-
3xx<isiozxuj
E- E- X
aoiJ>£lbXai£tX OU. H H U W <
QDDHUUUZOOOHUHUUQKOUOa
<U1£QCJiX<hK|i 14JUU Z £ £ Z Z CL bl
Q. , Q. l a. l c. l a l Q. l a l o. l Q. l a l a l cL l Q. l a l a l a. l Q. l Q. l a. l o, l a l cL l
) i x
: i x
I W>
f >d <C IB 1C «
nn ib m O'o> O'O's< < ill u lu
aaaaaoauuoaoa
0'<QUU.QSn'B'B'0'6'B'6l00'<QU'
blulblblblb.b.b.b.b.b.b.b.b.b.b.b.Ci.b.C
~ — ~ _ QBSSSSSSOSQSSO!
no>u(blL(L[i
ini/ir'O'dlQlu-ninr'O'O
-IO'S-(Nn»tu'iOI'#3'QH(NJO<
SiOiBM'i'r'r'r'p-f'f'r'coacocoa
i030isnssE5.st:
0O'®-1(N''IVlC''Br s M0
Sf'tOO'S-
b®®®®®®®®
•J H J
>. 3 J X
JUIDUl
a —
j
J x J
WQH
Z X
Ct. < o
IcSK
O u
Z D3
b- «t O
b. X X
< E- <
«</!>>
ui x a
E- «
WQH
Z D3
b- < O
U. X X
O U1
Q. U
a o «
Z Cl
< t- <
tcw>
UJ X u
a. —
O b. o
< bl
3 in
in a
> a,
a. o £
O as D3
a cl n
U)K z
z < -i <
NB.O «
CL £ bl X
O o | cn
cl u a x a.
Z < -« ®
<n a oo
CL £ bl bl
O O II
a. u a. a.
cn x
z « — ®
fN O. O O
a £ bl bl
Z =
<N a. ooo
0. £ bl bl bl
O O III
a u a. a cl
a ® cn
O - l
a. a a.
J E-
< bl
u x
J -1 CL
< < O £
u u n n
j j
< < u t>
u o n*-
4 X CL
< u £
u*n
J o
J X 0
gy;
>OX>4H
)£00£0<u
EU££U£OX
bl ui
a _i
- aJa. 1
■"B O' O' O'O' u b. c
'r'r-r~r'r'p'r-a
r'CS^cNi'-ivi/ivcir^ci
ococococooooococoa
D « <6 <B >B <B U
b ® ® ® ® ® a
f in'or'coo'«
rT^r-coo><(auQs----(-'fr'<<<c<Qsnm
ommmmmcDXfflxouoouououuouQQQ
f> ® HNn<TU
Dl'COffiSHNmr
ri'BMOO'S'
Page 40
422
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
A MICRO-BASED PROJECT FOR THE
HANDICAPPED
Dear Madam or Sir: Received: 78 July 31
The Spain Rehabilitation Center at the University of
Alabama Medical Center has a project underway to demon¬
strate both the utility and economic feasibility of the new
generation of ‘personal’ computers for use by the severely
disabled. The programmability of the computer will allow it
to serve as a general purpose appliance to be used as an aid
to communication and education as well as for environmental
control and entertainment.
This system, as currently envisioned, will consist of a micro¬
computer, an on-line storage device for programs and data,
two T.V. monitors for user feedback and information display,
a printing device for typed output, a speech recognition
device for vocal input of commands, data, and text, a
powerline controller for environmental control, and a
telephone dialing/answering device. We are attempting to
select components which are widely distributed and serviced
as well as being plug compatible and economically priced.
Programs will be written or purchased to perform specific
functions in each of the four general areas mentioned above.
However, we would be very interested in receiving ideas from
your readers, particularly those who are disabled, those who
have disabled friends or relatives, and those who have personal
computers and would like to develop hardware or software
for the system on their own, regarding specific functions
which they would like to see developed and which could
be accommodated by the proposed micro-computer system.
Sincerely, Spain Rehabilitation Center
Charles Healey U.A.B. University Station
Research Associate Birmingham, AL 35294
(205)934-3320
COMMENTS ON KIM CASSETTE PROGRAM
Dear Mr. Warren: Received: 78 Aug 14
Now that Dr. Dobb’s is slowly beginning to publish more
6502-oriented material, it’s left the never-never land of
“good computer magazines” to become a publication that
I can actually use ... and perhaps even take issue with from
time to time. The basic motive for this letter is to comment
on the “High Speed KIM Cassette I/O” in DDJ #26. While
the high-speed facility is useful (its usefulness being, roughly,
in direct proportion to the KIM users’ exasperation with the
normal monitor program’s rate of cassette loading and dump¬
ing), the approach in #26 is the third version of a high-speed
binary load/dump to be published in the past year. To my
mind, the best of the three is Robert Tripp’s “Ultratape,”
which is discussed in issue #1 of his 6502-oriented magazine,
MICRO. “Ultratape”’s superiority derives from the fact
that the program search capabilities of the KIM monitor
aren’t lost as they are in the other two versions; the tape
header and the first byte of tape data are in a high-speed
ASCII format (Jim Butterfield’s “Hypertape” format—which
is the normal KIM format, and monitor-compatible, at 6x
normal KIM rate) before dropping automatically into binary
format for the rest of the dump. Not noticeably slower than
the version you published; but for those of us who need the
tape search provision, a superior program. As well, the pro¬
gram in #26 uses parallel port bits PB2/PB3 to control cas¬
sette deck function. While author Bridge has kept this com¬
patible with the original control subroutines in MICRO-ADE,
similar cassette control routines are used in Tripp’s “HELP”
utility file programs for the KIM-but toggling PB0/PB1
instead. Since changing a constant or two in a program is a
lot easier than rewiring the parallel port (although the cir¬
cuitry change is fairly trivial), in the interest of compatibility
the constants in Bridge’s tape control subroutines
(and in MICRO-ADE) could easily be changed to toggle bits
0 and 1 instead of bits 2 and 3.
While I’ve got your ear, I should pass on to you the names
of three distribution points for computing equipment and
insight whom I’ve found invariably reliable and fast:
1. Forethought Products, POB 386, Cobourg, OR 97401;
the manufacturers of the KIMSI KIM-SI 00 interface/mother¬
board, they produce a quality product with excellent docu¬
mentation and service, and have responded to my many
queries and comments quickly and thoroughly;
2. Arisia Microsystems, 1455 Gregwood Rd., Mississauga,
Ont. L5H 2T5 and
3. Orthon Computers, 12411 Stony Plain Rd., Edmonton,
Alta. T5N 3N3 are two Canadian dealers (primarily of S-100
equipment) whose prices are fair (in most cases better than
I would do importing myself and paying duties/post/exchange)
and service fast and reliable.
Peace. 25 St. Mary Street #411
Barry Tepperman, M.D. Toronto, Ontario M4Y 1R2 Canada
DC HAYES RESPONSE TO MODEM COMPARISON
Dear Sirs: Received: 78 July 18
In Volume 3 Issue 6, Jun-Jul 1978, you printed an article
by Tim Pugh entitled “Intelligent Terminal Implementation
for the S-100 Bus.” I enjoyed reading the article. It was
informative and well-written and the program looks good
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 41
423
though I haven’t tried it yet. Unfortunately, I am writing you
because the article contains several inaccurate statements
about our S-100 modem, the D.C. Hayes 80-103A Data
Communications Adapter.
Mr. Pugh points out that we chose to use the simpler
MC 14412 modem chip instead of the MC6860, which
provides several automatic functions. This consists primarily
of some simple answering logic. We found it to be less
expensive and much more flexible to implement these
functions with a separate I/O port and some software (less
than 10 instructions in 8080 code), which can give the user
such capabilities as answering on the Nth ring, etc. For
example, one of our users has programmed his machine to
listen for the phone to ring. If the caller rings once and then
hangs up, it answers the next call. Otherwise it lets the phone
ring. This makes it unlikely that someone who doesn’t know
about modems will get a squeal in their ear when they try
to call you. The 6860 always answers as soon as the phone
starts ringing (well 51 milliseconds after). This will work
even if the CPU is not running. This means it will answer and
accept a long-distance call even if the system has crashed.
The design criteria for our modem was to get the most
performance and flexibility possible for the least money. As
Mr. Pugh notes, our modem is about $100 less expensive
than the IDS board.
The filter specifications in the Motorola application note
are quite conservative. We do publish a recieve sensitivity
figure (—37dBm), which is sufficient for reliable operation on
about 90% of all long-distance calls. Since the digitally-created
signals from the MC 14412 chip contain very little energy in
the harmonics below the 13th and 15th (which occur in the
25-40 kHz band), all that is need on the transmit signal
is a simple low-pass filter to keep these harmonics below
—40dBm. As Mr. Pugh points out, filters are pretty compli¬
cated and require a lot of expensive parts. Since we wanted to
keep the price low, we felt that the additional parts to get
98% were not justified. We are sorry that Mr. Pugh did not
try our modem in a full-duplex configuration, because it
does work. On page 44 of the same issue, there is a letter
from Ward Christensen describing a system using our modem.
It normally operates full-duplex, and has been successfully
used by dozens of people from all over the country.
We only provided two baud rates (110 and 300) because
those are the only standard rates for ASCII. Our manual does
provide detailed information on rewiring the baud rate genera¬
tor for non-standard baud rates, however.
We didn’t provide a dial tone detector because a simple
2-second delay is adequate. Telephone company design
rules virtually guarantee that properly functioning telephone
exchanges will provide dial tone within that time.
The auto-dialing capability of the IDS modem merely
creates the pulses, which is not the most difficult part of the
dialing software. It still requires software to get the phone
number, and to feed the digits to the dialer. I have rewritten
Mr. Pugh’s subroutine DIALIT (which dials a single digit)
to work with the 80-103A. The original consisted of 11
instructions occupying 28 bytes, the modified version
contains 22 instructions occupying 49 bytes. Since I don’t
believe any program works until I see it with my own eyes and
I haven’t run this one yet, I can’t guarantee that it works, but
it is pretty simple so I doubt that I made very many mistakes
in it.
We did not provide power for the coupler because the
standard S-100 bus voltages are not high enough to meet
the telephone company’s specs for the coupler (20-26 vdc),
and the telephone comapny specifically requests
non-switched power. Telephone company power is usually
about the cheapest option available for a coupler. And if
it’s not, a 24vdc power supply is not very expensive.
The 80-103A is designed to use a DAA, and our manual
is quite clear that although it will work when directly
connected (it does have a ring detector), it is not legal to do
so in most places.
AN I
0FH
ISOLATE DIGIT
JNZ
D1
CHECK FOR 0
M VI
A,10
AND CHANGE TO 10
PUSH
PSW
SAVE THE COUNT OF PULSES
OUT
MODEM2
A DIAL PULSE IS CREATED BY OUTPUTTING
A VALUE CONTAINING 0 IN BIT 7
MODEM CONTROL REGISTER
TO THE
MV I
B, 2
STANDARD (10 PPS) DIAL PULSES
LAST
CALL
DELAY
ABOUT 60 MILLISECONDS
MVI
A ,80H
END THE PULSE BY SETTING BIT 7
BACK
OUT
MODEM2
TO A 1 (OFF HOOK CONDITION)
MVI
B , 1
DELAY ABOUT 30 MILLISECONDS
CALL
DELAY
BETWEEN PULSES
CALL
CSTAT
NEXT 3 INSTRUCTIONS UNMODIFIED
JZ
D2
CALL
CR$ST
POP
PSW
GET THE COUNT BACK
DCR
A
DECREMENT IT
JNZ
D1
KEEP MAKING PULSES TIL IT GOES
TO 0
MVI
B , 15
INSERT A .5 SEC DELAY BETWEEN
DIGITS
CALL
DELAY
MVI
A, *-•
UNMODIFIED FROM HERE ON
CALL
RET
TCHAR
We recommend renting the DAA from the phone company.
The DAA is a pretty silly gizmo and really doesn’t do much
other than introduce another couple dB loss into the circuit.
But when you rent the DAA, you get treated as a data
customer. Most data customers are big companies using big
computers. They demand the best service and get it. With
the DAA, you are paying for that service and you can demand
it too. Telephone company design rules for local loops
(the pair of wires from your house to the central office)
are more stringent for lines with DAA’s, and when they install
your DAA, they take more time to make sure you get a
good loop. This is important because local loops lose more
data than long-distance lines. With a bad long-distance line,
at least you can dial again, but if your loop is noisy, you’re
out of luck.
We don’t sell kits because we believe that they don’t make
sense economically. We found that the actual difference in
cost to us between a kit and an assembled board is only about
$10. Rather than create an artificial price difference (and a
lot of headaches for us and our customers), we decided to
assemble them all in our factory. All of our boards are tested,
burned in for 48 hours or more, and tested again to assure that
they meet all of the published specs.
I am presently modifying Mr. Pugh’s program to run with
our modem and intend to submit it to the CP/M user’s group
as soon as I get it working.
If you would like information about our modem, call or
write us. We make a real effort to answer our user’s questions
and to help them make their systems work.
Respectfully, D.C. Hayes Associates
Donald J. Hyde P.O. Box 9884
Director of Software Atlanta, GA 30319
Development
Page 42
424
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Number 29
MORE ON FORTH IMPLEMENTATIONS
CLEARING 6800 MEMORY
Gentlemen: Received: 78 Aug 18
I read John James’ “Forth for Microcomputers” in Volume
3, Issue 5 with great interest. I have been involved with Forth
and Forth-like languages since late 1975, and am one of the
promoters of it at the University of Rochester. To clarify your
article’s last page, the University of Arizona, (primarily the
Kitt Peak Branch of AURA, Association of Universities
doing Research in Astronomy) is running single user versions
of Forth on CDC 6400, HP 2100 and Varian 6201.
At the University we are running a multi-tasking Forth
called URTH on the following machines: IBM 360/65,
INTEL 8080, MODCOMP II, HP 2114, HP 2100, PDP 11/34,
and soon the LSI-11. These are used for applications as diverse
as laser control, fusion diagnostics, data entry, telecommunica¬
tions and image processing.
We also have a manual, and will be setting up software and
manual distribution shortly. Anyone interested should write
me at: The Laboratory for Laser Energetics, 250 East River
Road, Rochester, NY 14623.
A technical Forth/URTH internals manual is being pre¬
pared from a series of talks and workshops given at the Univer¬
sity during the past year.
In reference to your comment about micro-coding the
Forth interpreter, it has been done for an HP 21MX-M com¬
puter, and was reported in the European Southern Observa¬
tory technical note LS 76-119 by S. Lorenson dated 10/
29/76.
Good luck to all who are interested in Forth.
Sincerely yours, University of Rochester
Lawrence P. Forsley Laboratory for Laser Energetics
Rochester, NY 14623
SOFTWARE [IDEAS] FOR 50<t
Gentlemen: Received: 78 July 12
Perhaps your readers would be interested in another soft¬
ware source — the U.S. Patent Office. Statutory disclosure
requirements are such that systems patent applications should
include software. A patent recently issued to Hewlett-Packard
(4,089,059) contains software for a 6800 based system. While
not directly usable because of hardware differences, the source
code may be of interest to those with 6800 based systems. Pat¬
ents may be obtained for fifty cents each from
Box 9
Patent ^Trademark Office
Washington, D.C. 20231
Anyone interested should be prepared to spend a fair
amount of time studying: in the patent mentioned above
there are 226 drawing figures, 20 pages of text and 150
pages of source code—the patent is 1% inches thick.
Very truly yours, 165 Hurd Road
Paul F. Wille Aurora, OH 44202
Just remember that the software mentioned is also protected
by the patent in which you read it. The purpose of patent
disclosure is, of course, to inspire further invention but care
should be taken to avoid infringement. -TRW
Dear Dr. Dobb’s, Received: 78 July 28
Your September 1976 issue contained a letter on page 32
from Richard Kaapke which described, among other things,
a nine byte 8080 program for clearing memory. Last night I
decided to try something similar for the 6800, and devised
the following.
Routine 1 (8 bytes): fill memory with NOPs. Properly
assembled, this routine will execute anywhere in memory.
2000 8E 20 03 LDS 0STACK
2003 86 01 STACK LDAA i?N0P
2005 36 PUSH PSHA
2006 20 FD BRA PUSH
Routine 2 (5 bytes): fill memory with zeroes. This routine
must reside at the addresses shown, and assumes that execut¬
ing an opcode of zero is identical to executing an NOP.
FFFB 8E FF FD LDS 0HERE-1
FFFE 8D FE HERE BSR HERE
Routine 3 (8 bytes): fill memory with ones (all bits on).
This routine must reside at the addresses shown.
FFF7 8E FF FA LDS 0THERE
FFFA CE FF FF THERE LDX tfHERE+2
FFFD 8D FE HERE BSR HERE
Assuming that every location in the address space acts
like RAM (ie, can be read, written, and executed), then all
three routines fill ALL of memory, obliterating themselves
in the process.
Sincerely, Box 2692
Mike Gabrielson Stanford, Calif. 94305
(415) 493-5217
REPORT ON WELLES FLOPPY CONTROLLER
Dear Dr. Dobbs, Received: 78 July 20
I think you may be interested in one readers’s experience
with the Welles Floppy Disk controller and FDOS Software.
After reading about this modern wonder in BYTE, I ordered
a blank PC board from Dr. Welles. My order was confirmed
after a week or so, and I had my board in about 5 weeks.
This is not in any way a kit, you should know all about TTL
logic (or be ready to learn). I replaced all the 74XX and
74LXX chips (except the 7438) with 74LSXX, so that the
card now runs a lot cooler and some of the signal lines look
a bit cleaner. There were a few errors on my card, but they
were all covered in the documentation that came with it.
After working with this system for around 10 weeks I can say
that it really works, the FDOS software works well, though it
lacks that “polished” look and may give you some odd results
every once in a while. It has not yet dropped a file, however,
believe it when it says I/O error. I feel that nothing else I’ve
seen comes close to it for the cost. (A little under $600.)
Shopping around lately I’d found everything from about
$450, the key is finding a drive for $350—it can be done.
Sincerely, 408 Oakwood
A1 Marshall Angola, IN 46703
Number 29
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, Ca 94025
Page 43
425
Dr. Dobbs louRNALof
COMPUTER
(Calisthenics Orthodontia
Running Light Without Overbyte
Number 30 November-December 1978
Volume 3, Issue 10
SOFTWARE
A LISP interpreter for the 8080 Darrel Van Baer
Documentation and complete source listing
4
Curve-Fitting Using a Focal Interpreter on the KIM-1 Theodore E.
Bridge 12
Binary Tree Manipulation on the 8080 Mike Gabrielson
A tutorial treatment
15
Programming Languages and Standards David Chapman
18
SAM-76 Language Update Ancelme Roichel
19
BASEX: A Fast, Compact Interactive Compiler Paul K Warme
Description of a new intermediate-level language
26
Tiny GRAFIX for Tiny BASIC Joel Swank
A subroutine package for Tom Pittman’s Tiny BASIC
32
Copying a Diskette on Intel Double Density DOS Paul M. Julich
40
HARDWARE
The Heath H-8 System Tom Williams
Featuring Heath’s new diskette system
22
The STD Bus Keith Britton
A critical look at a proposed new standard
i __
34
© David Dameron 1979
A LISP Interpreter
for the 8080
BY DARREL VAN BUER
1522 Brockton Ave. Apt. 5
Los Angeles, CA 90025
As assembled here, entry is at zero. Most of the code may
be anywhere in memory but all LISP data elements (CONS
cells and atoms) must be in the first 32K of memory. The
interpreter is completely self contained except for terminal
I/O. On input from the terminal, all control characters are
ignored, and thus may be freely added to improve readability.
All input is parsed as literal atoms and S-expressions. An atom
is any string of alphanumeric characters not over 16 characters
long. Some examples of legal atoms are:
ATOM 934 A47 47A
Some examples of illegal atoms are:
VERYLONGSTRINGOFLETTERS (More than 16
characters)
AD-P (Contains non alpha¬
numeric —)
The only other characters recognized by the system are
left and right parentheses, commas, periods and blanks.
Consecutive atoms in lists and S-expressions must be separated
by at least one of these symbols to be recognized. Blanks may
be optionally inserted before left parens and after right parens.
Both input and output routines can handle mixed S-
expressions (with dot notation) and list notation. The output
routines will always use list notation whenever possible, but
will use dotted notation whennecessary.E.g.,an S-expression in¬
put as: ((INTEL.NIL).8080) would print as ((INTEL).8080).
Logical values returned by EQ, ATOM, NULL and EQUAL
are T and F. These must be quoted when used as constants in
a program. These are also the logical values expected by COND
(actually COND only tests for T).
The interpreter is an EVALQUOTE mode interpreter so
two S-expressions must be entered for evaluation to occur.
Both of these S-expressions must be followed by a blank
to allow for the lookahead used in READ. After recognizing
the second S-expression, which is a list of arguments to which
the first S-expression (typically an atom) will be applied,
both of these expressions are effectively quoted, so all atoms
in the expressions stand for themselves, not any DEFINEd
binding. Once the interpreter recognizes the second expression,
it does a new line and types *»’ followed by the result of
the computation.
For example, if the following is entered as input:
DEFINE(((TT)(F F) (FF(LAMBDA(X) (COND((ATOM X)X)
(T(FF(CAR X))))))))
the interpreter will respond with:
> > (T F FF)
If you then enter:
FF (((A.B).C))
the interpreter will respond with:
>>A
The following functions are defined as built in subroutines:
ATOMjx] T if the value of X is a literal atom, F otherwise.
NIL is an atom.
NULL[x] T if X has value NIL, F otherwise.
CONS[x;y] Returns a new S-expression whose CAR is X
and CDR is Y.
CAR[x] Returns the CAR portion of a CONS cell. The result
is undefined when applied to atoms.
CDR[x] Returns the CDR portion of a CONS cell. Unde¬
fined for atoms.
EQ [xy] Returns T if X and Y are the same atom or the same
CONS cell, F otherwise.
EQUAL [x;y] Returns T if X and Y are EQ or are congruent
trees. Objects which are EQUAL will print identically
although they may use different CONS cells, and thus
not be EQ.
CADR[x] Same as CAR[CDR[x] ]
CADDR [x] Same as CAR [CDR [CDR [x] ] ]
DEFINE [x] X must be a list of definitions. Each definition
is a list whose first element is the name receiving the
definition and whose second element is the definition.
The value is a list of the names defined.
EVAL[e;a] E is an expression to be evaluated. A is the assoc¬
iation list defining the environment for evaluation.
The value is the result of this evaluation.
APPLY [fn;x;a] FN is a function name or functional form,
X is a list of arguments for the function and A is the
association list to be used. The result is the result of
applying FN to the arguments in the specified en¬
vironment.
ASSOC [x;a ] X is an atom whose association is fetched
from the association list A. The value is the first CONS
cell from A of the form CONS [x;value].
Page 4
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
429
PAIRLIS [x;y;a] X is a list of atoms, Y is a list of values,
A is an association list. The result is a new association
list consisting of the old association list preceded by
new association cells constructed from pairwise joining
of elements from the list X (for names) and Y (for
values).
The following are special forms recognized by the inter¬
preter:
COND[ (tl vl) (tl v2) ... ] COND is the conditional (“if’)
element of LISP. It takes an indefinite number of
arguments, each of which is a two element list. COND
successively evaluates the first element of each of these
lists until one is found with the value T. The value of
the COND is then the result of evaluating the second
element of the same list. If none are T, the result is
an error. (For this reason, the last pair is usually of the
form ((QUOTE T) expr)).
LAMBDA[v;e] V is a list of variable parameter names.
LAMBDA is the function designator of the LISP world.
When a LAMBDA expression is applied to a list of argu¬
ments, the arguments are paired with the variable list
V (via PAIRLIS) on the front of the current association
list in EVAL/APPLY. Finally the value of the expression
E is evaluated in this new environment and returned.
LABEL[1 ;e] LABEL is used to associate the expression E
with the label L then evaluate E in this environment.
The primary use of LABEL is the definition of temp¬
orary recursive functions (as opposed to permanent
definition via DEFINE). For example, the example with
DEFINE and FF earlier could have been done as:
(LABEL FF (LAMBDA (X) (COND ( (ATOM X) X) (
(QUOTE T) (FF (CAR X)))))) ( ((A.B) .C) ) »A
Here, FF is only meaningful inside this expression,
whereas after DEFINE, FF is a permanently known
function.
Internal Organization of the Interpreter
All free memory in the first 32K is used as non-reclaimed
storage for lists and atoms. Because there is presently no
garbage collector, problems are limited to those with at
most 8000 CONSes (in 32K).
For built in, assembled functions, the calling conventions
are as follows: HL passes the first parameter and returns
the result (except that functions which return only T or F
such as ATOM return T by setting the Zero flag and F by
non-zero flag). DE passes the second parameter and BC
passes the third parameter. BC and DE must always be re¬
stored to their original values before returning. HL must also
be restored for T/F functions using Z/NZ returns. For
functions with more than three parameters, BC and DE are
not used and HL passes a list of the parameters. Note that
there are no functions with more than three parameters in
the system at present, but APPLY has code to follow this
convention. Assembled functions may call one another di¬
rectly.
The interpreter has two permanent internal association
lists. One is the list ASMFN (at 0637H in this listing) which
is a list of all assembled functions. The value of these atoms
are CONS cells in which CAR is the real memory address of
the code and the CDR is a flag describing the function. This
information is in the L byte. The high order bit (80H) is
on if the function returns T/F as Z/NZ. The low order bits
are the number of arguments. Zero is used if more than
three arguments.
The other list is initially NIL, but is modified by DEFINE
to include new definitions. This list is the initial association
list used by EVALQUOTE when it calls EVAL. This list is
stored in EVQAL (AT 04B4H).
The interpreter also maintains a tree used by READ to
record all atoms known to the system so that only one copy of
each atom is kept. The initial state of the tree is computed
following START (at 04CDH) and stored in NAMETREE (at
042FH).
The interpreter is fully reinitialized following reentry at
zero. To reenter the interpreter and keep old function defini¬
tions and known atoms, the interpreter should be entered
at INLOOP (at 0599H).
The I/O routines required for the interpreter must pass
the character in the accumulator with high order bit zero.
Further, they should restore all registers before returning.
Equates for the address of the pertinent routines are in the
first few lines of code. If you patch the object code instead,
OUTC is called in 5 places following OUTPUT (0050H) and
two places in EVALQUOTE (028EH). EVALQUOTE also
calls CRLF, a routine which should send CR, LF and whatever
nulls needed in your system. The only call to INCH occurs
in NEXTCHAR (at 0348H).
•X 15 Z)
3 < -U
UUh
x as c
z 2 co o :
j y £ .
^ Z 'T J ■
£ :
a w q
> > a ch :
< < a m «
CflTIZOt
■3 x ■a m ■s
33 a a a
ii '3 '-T X Lij Cij
a r- -o a a a
3 3 3 3 3 3
O O O O O O
UJ id ty CU aJ
C X X 2 £ £ < 2
-* O Q r J3 * - * CO
'JCJCJ^CXICJCL
‘-3 33 35 c 1 J
£XQ£
> >: a, >
0200
t H Q, Z
J X I Cu Z
H £ Ci3 u J a
3 a x z as cq
* *
■-H -N -Of'-COON
aaaaaaaaa
a aaaaaaaa
s aaaaaaaa
Q 15 rM r/>
Q Q X X x 2
< < < < Q O
UUU'J cj tj
r-\ —I -H -H —I -H •—I .-f rH —I rq ,-N f\J CM CM .N iN ."N tNJ rs) m r
a a a a a a a aaaaaaaaaaaaaa-
a a a s "S a a s a aaaaaaaaaaaa;
a
a
<
a
uuoar^r«j.x>vOii,oa.>j-NoQa-HOQ
m r-
s aaaaaaaaac^
a aaaaaaaaaa
a aaaaaaaaaa
a aaaaaaaaaa
sD'T.<OCJQoJi J arHrNr^
aaaaaaaarH^H—(r-t
aaaaaaaaaaaa
aaaaaaaaaaaa
sDC^-3JCQ'i]ti,a^liNrO<^
H H H H H H M .N .N (N ,N
aaaaaaaaaaa
aaaaaaaaaaa
Number 30
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
Page 5
430
X
>
— '3
X <
< X
03 0
S 3
3
< t/3
£
T p
b <
x
o x
2 >
II <
x x
: <h 03
: os > -
» X < -
' % 03 '
X S
Q O
o x
O 03
O X
— X
X XX
03 — < <
J<UU
X — — —
H J r ^ J
J < O 2 <
x o .< -> o
o
O H
03 c
J X X *J E
C M J H J t 03
O Z < -1J < O ea 3
x x o x o x n x
<
OS EE
< < o»
: o o O'JQi
: x J y J J
I 03 X X X X X X
3 < o < < o o
1 u x u o x a,
TOO CJ 03 Q T
T T J O X
S3 03 03 -J T O
2 3 3 * O <
s % 1 O X 'J
o-.ro 0 x 00
J 3
J O
3 Si
Z < TO
J 3. 1 7 I H (h
o o a j! j
U 13. is o X
< N >
o z o
3 Z
J 03
< >1
X X 3 5h X
< < O D <
U O 03 Z X O O
X J X
X X X X 3 X 3 X X X 3 X 3 X J J I X J J mmm -«
>rH r .O'.nyiXXXXXXXXXXXXXXXXcH:/i71XX3XX5HXXXsaXXX'HX
O03333<O<CO<O5H<COCO<0O<OX 3 EO<ZOOX<<<“-~~'^ '
Z E 3. Q. 3. o X O X O 1 X ’ 1 ^ ’ 1 ’ 1 ' ^ f 1 f '. V A. A. sa> f 1 A. A. V- r 1 r . r >
I<0<05H<0<0<00<OX3 30<
lOiXOXXOXO^OXXUX X X X X O
ZOOX<<<ZOO<XO<
TllEOOOTlVJilU
‘ J3 J s x> 31 3 -
• t J~t as » j ^ -
' r> n f'' a 31 3 -
- j~> o r-- jo j\ 3 -
O >1
O O
■Ji -Si
Ji t Si
< <
P XI ^3 Ml 3\ 3 -
iinminiriinji.n^^^’O^'O^ncvDvO'XJSsr'Ssr'SsssajxHDJoa
33 3 333 3 3 3333333333333 33333 3 33 3 333333333 3 333 3 33333333333333333333333 3 333333'
O
X
X
JI o O.NOJ'3aJ'Qll<i/1-na'tl3DHH3iriyi3I|Qa-lHJiC3\Q,NSJ13'yii/iy'a3lDllQH'rQaQaQH2ia-iui- l
O O X o o X O O O O X o X 3 O X O O o 3 o x Q O X o O 3 > X o o- o O O >0 x O 3 X 3 o r X O X O a 'X o X o X O Q 'X O 3 o Q
N’'ir'<3Xi,N"'i0S<!IlO*3' , ''Dr'33Jl<Iia!i..N l /l'i)S»<!3Hi]HiN' , l^yi^S< , ll , ja..N'*lq l S»aOj.3"l^in'BS»a'OIi
X X X .0 X X X 3 o O O O O O O O 3 Q Q 3 3 3 3 3 3 3 X X X X X X X X X X X X X X X X X X X SJ 3 3 3 3 3 3 3
3333333333333333333333 3 333333 3 333333 3 333— - — — -
1 3333 3 3 333333333333 3 3 333333333333
3unif1'aQiNHH3'QQQNHH33'H3
“Qxooxa 00000 x 3 o o x o
33333333
U U U Ll -1 -I U LU UJ U IU U Ol 'il it. i. i. i. « u. Ill J, Ji Ji 'i.
3333 3S3333.3 33S333S33333S33i— 1 »—i«-ai— i-^— 1 »— 11 —!•— 11 — 1 <— 1 <— 1 <—i-a'— 11 —i--a
- --— 333 3 333333333333333 3 33333
>1 Hi 00 X X X
4 !N ."N .SI .N -SJ '
33333333 3 3
XXX
Q <Si 3 X
EES
O 5h Eh <
►h 'Ji
X 3 X
- O m X X
Eh x O —•
— P-H Z
j. H E *
>-h Ji D *
H^hQ
H J < W —
x X ►
< X X
Z 5h Z X X <
O Ji O x 3
C-h X 5h I O O
h < sa X X
J X X
• > o
< o
1 Ji X
3 3
Z E
X Eh
I 3
N II
z <
O e
X < *
Z Eh *
<
X X
< o
X z
X X
3 X
O E
X 3
E O
x a .
X z t
Z X '
X
X <
> X
3 X
O X
X X
X 'Ji
< XX
E X < >
> X ^
X < Si
> n ;h e
>h x 3
> Q T O
TXT
■* 3 3
< 3 JO
Q X E X X
X O O X 3
X < X O H z .
X
X X z
3 Z •*
5h O 5h
< 5h <
TECS
<X < X XZZTECZXCr'XCOTCOTCTE
• XXX
-3 XX
< O
EX iX X O * XXE5 h- H E • •
- < 3 X 3 X *■ 3 -H < 3 - 3 0 3 - D
XXOOTOZOCOZOOCOT TOO COX
X>XXX£H>^H-i ( rH>EN>EcH
zooooxozexos Z O S X
xZQOQEZCOESOESOE
XXXX XX XX X XXTXXXX X XX X XXX X
XX XEXEIH hEN^E5‘WXnhEXsJ'J1>h>>X>X1nEE Xi— iXX>a(/)XXEXX mXEXXxXE OXX^hXE
3<fO<S<0'X>SZESX3<ZXS<Z30ZOOZO<OZOOX><<Z3<<0<<sa><S<<><0 3<<><0
EOOOoOEESOEXOEEOeXoOeESCSSxSOQoEEESOOeEOOEOOOSOeOOSOEEOO'SOE
Eh Eh
!i1 , OSJ3J'OH.N'^^ , in'Or''B3'3HN' y Pfl l i/l'Cr v » J>3H’Nf r l<fUTai s -X0NaH.N' , P^yt'Or'J0J'3Hi'N' , 1fi/1.0r s JO J' 3 H -f in 'fl S J) J\ S3 ,—( .N "P ■a 1 in 'll r' o
-^ rr . r r.nr«^qi rr « T ^j.^j.^j-» T ^-^j.^. t n 1 j-,j- 1 ,/^ u -, t /- )L r ) i/^ L nmvo^O'rvO'X>vOsO i ^>vovor^r~r^fH-rHrHrHr^ r ~rH-xwx l xxxJOXXxo>o>o>3><T> ( T>3>Ji- : rti3>3333333 3 33
33333333333333 3 3333333333 3 33333333333 3 3 3 3333333 3 333333 3 33 3 3333333XXXX-HX—IXX—)
3333 3 3 SS333333S3333333 3 3 S33333S333333S33333333333S 33333333 -3 33333 3 33 33333333
3 3 3 3 3
3 3 3 3 3
3 3 <r 3 3 (S>
3 3 3 3 3 3
333 33 3 33
E 3 3 S3 333
3
X
S3 3
3 3 X
3 3
JO JO
■J -3 X J> 3
TH" , 'T 00
^ Q Ji CQ 'JI X
^ '/no cn r-
JI JI
3 ■£>
CO JI |h JI JI 3
CN 3 rn TS s m
3003JT.3Ti.3XJ1
H^CMOXS^.N 3
r.'N'DU213'U , 'OaJ'U<3QfflO\iDQ<a"'QHJ'U03&iQIJl/lQiNH«Q!MinU'OMO"IMQiDMHH3WaOQ.NifiQQHaQ<UQ' , 'QQXCHiDQaaaH
sjr''Nj.-N.s40r-XE0^X0r-X0X0 00 00X0'^T0<X0X00 r N0000f^-XX'Trsjr-0300X0'^000X0 0X000' v '000 0^0ax00' Y '0X
i/t O S JO JI <
.“N -U JNI -SJ CN CN
3 3 3 3 3 3
3 3 3 3 3 3
ra o X 3 X CN
N .N N -h « -n
3 3 3 3 3 3
3 3 3 3 3 3
if) X I CO
ro i-o r**
3 3 3 3 3 3
3 3 3 3 3 3
CO X i—I CO
rr> n ji^j.
3 3 3 3 3 3
3 3 3 3 3 3
U'BOQmsHTh
<r ^r^j-'T*j’’TiO)unu~)Ln
333 3 333333
3333 333333
<Q3' r "jinr'Xj.<iiii]i|tN' ,- ^xs<;asHtsx
ininxxxxxxxxxxxssssshssfflxxx
3333333333333333 333 333333
33 3 333 3 33333 3 333 3 3 33333 3 3
X X
CO CO
3 3
3 3
-O <0 Ol O X
31 JI 31 Ol JI
3 3 3 3 3
3 3 3 3 3
IT! v£>
< <
3 3
3 3
31 O X i-H
< < < X
3 3 3 3
3 3 3 3
Page 6
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
431
X
X o
< 05
U <
CO z
CU X
Z <
o
id
X d
X 05
Z X
O H
Z Eh
o
>-1 Cd
O U Eh S
05 05 U a
< < Z 75
a CO
Q E-* X <
Z CO E-»
CN ^H J (J X
II ii J H rj
13 J <SH
a x u o x
X 10
< o
Cu Ld
O Cd
Z 05
O
U 'H
OOQXJQCdQ
05 05 < **«••*<
<I<<UXUXJU
£h H f
< id •
X e-t X :
< - X
U X < :
X <
— X ~
< O J
ll - £h <
H •• z yj >
Cd X Cl 13 13
U Q — 05 —
X H
J J id
X U < XX
* •* > X
X Q Cd J Q < «.
X
z z
X o X
X —- X < X
> z > + <
< X < U
10 ~"75 < -—
<
Q
X T.
z <
< J
X J (H
< -OO
x u a a x z
- X —.
X —> Q
> z <
< X u
X •—
Q ►
_ < '
Q X X U £
u —
*H z
£ X
o —
t-* x
< <
X
a j
a <
< >
U X Q
J 6-» Q
‘ a o <
X X z Q X X u
a z
X < X
u u —
< - X
=H — X
X Z Q
X <
o — u
• ~ ~ O
• X z
Z H z
z XXX
XX —' u —'
— o
X u
a x ii z ii
< > •• o ••
u < x u u
— X Q '-’to
z x u z x j
o * -o * -
uqqxuxux
Z d
X X
— a
X j
a x
Q X
< x
u
— <
X X J
Q J
X - 3
X J z
X ^ X —
o < O X X
X - X > — <
X U X < u u
X •—’'d '—•
X X
x a <
X Z J J
3 d X tH XX
“230 < <
< < Z Z X u u
J X U X
J>>>>JXJeHI-t
JU<0000<U<XXNI
JdUCZEEUXUOSXn
t-t X X X X >
X O O X O O
J X X X X X.
^•J^X-CXX X X X X O X X X J XXXXOXUXX J O X U X XX XXX
>XXX<WXXMXNlXXXXXXXXXX 6 -tH-iXNXXXXXXXXXXC/)>>X>>XXXXXXiriMXX XXX
g<0SU3<3X<Z003<<Ut-'<<0XX<Z003<H<UE-'U<300<00 0UHU<0 , d><<NJ3i:<
"SUXT XUXXU^XXXUUXXUUXXXUTXXXUXUXXXUXZSUZSXXXXUXXSUUnXUU
X
vt3<£MXMc>fl^ 1 o v ovor'NNNr'NNNNr'acoacoma»®cDa)!J'3>OM3Myio\wo\3\wsss
•"N N CN CN N IN -NJ ,-N CN CN CN CN CN >1 N CN N CN CN CN N .N ,*M CN CN rsl N ,N N .N -s| ,-vj CN .>j .N .N N N M «1 m
ss , ssas'Ssis3ssssss'S , ss , sQS5sss3'3ss'SS'S'Sssssssss
(N>»i«tinior'COij»SH>N"3^in'or'co£i\aHM£nfl'in'£ir'a)a33H.'N«3^ , i/u£)
nr) m) r*) CT) rn nr) i'O nr) nr) nr) nr) nr) nr) nr) CT) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) nr) ,-r)
-S3a^3a03SS33SSI'33 l S0'3 , 3'333
39999399999 :
X 9
9 9
9 33 «T X
(9 S3 X 3) 00
S3
3
3 X
3 S3
3
3
3 3
3 3
X 3 3 CN 3 3
3 X 3 3 3 3
•-N CO Ci4 X
3 Q Q 3
v© t> r* u cn
3 3 v© x in
vO
T\
3> < X <
3 ifl 1*1 H
>© X xu x n*
3 x 3 x in x <r
l© V©
3 X
v© X 3 3\ < "T> CTi
J) X 3 «r x S 3
®X<<Q'«rQ.N®aXQO%-H<
UXUQu^'U'vo^ouxuu-'^U
—ixctixsjiQxx m q in
QUUXinincjQ^j XUQ
QfN-HrHLOQQcQXQQ^H^^HQrNf—IXinQXQCQXCQQinsO>Q'»TQXX ro XQX£TlXQQ<inQQ
UUQXXUUXXUUOUxUUQXXUXUXXXUOininu^ , '^ , X'dXXUUUXuUUXUU
XUXx^rr^ooo><mxx>‘^xv©<T>:
UUUQQQQQQQOQ'dXXX:
XXXXXXXX—4XX'—I'H'Hr-H'Hr
S333SSS33S333333'
QXX SH.NlTl'OTlTl<0[jH<jr'XJ'<
XXXXXXXXXXXXXS333S3
XXXXXXXXXXXHX.'NMINMMM
3333333333333333333
Q3XCNinoO!Tl<QSX^TinvO<Ti<QX
3XXXXXXXX£NCNmrMtNfMrM.-NCN
^MtNtNIM.NNMfN.NfNtNtNtNMINNtN
333SS333SSS33S33S3
X3X«Tini©!Ti<XOQXXiNXTT^JJ<
CN X X XXX X X X X X X X “3 1 'J 1 'T
CNCNfNCNCNCNfNfNCNrNCNr'ICNrNCNCNCNiN
33333333 3 3 3 3333333
£N
3
X 3 X
v in in
CN CN CN
3 3 3
<
d
d
x a
d -
os X
- E
x —
X
<
U d
II
d
X
z
X
z
II
X
d
a —
z •
d —
d 4:
X -
< d
- u
OS o
O n
d d
d <
d —-
•N
o
n
n
<
ic <
O
x d
O X z
0 X d X
73 d 0 a
< z < u
u
33
z < d o OS
os o x o x a
< x D - O D <
XU<zaadZQ-EU
•o
X
>
d <
U — d
33 X X
— o
d X X
> < X
< U d
U3 — 05
<
a
x
x
23
d
n
n
<
o
n
O
x x o
> > 73
< < 73
73 73 <
U
Z
a
x
<
>
x
X Z
X Cu
n. a
x a
x o qs
X o <
X u
-X
<
H
<
a
z
O
IX X
U X
Z II
a x
x a
z
X
X
X
o
<
a
z
o
u
a
a
3
x u
a >
e u x
73
a
x x
a >
u x
0 £E < U X <
< 33 X < U X
X
x n u
X ' «
< a x a
s: u
z < x o
O z < x
X X - X
< < a r a <
x
X
x a
X E-* Z X X X «
a o x Q - ^a
z z x u a x u
H ^ >
X Z X <
U x o c/3
X
x
X
E-*
Z X
x >
O
X X
\
Z H
X
a H :
H x 5
x x c
X x c
X
\H
Eh Z
m Eh
OS O Z
O X x
x o
X z x
H NJ X
x z a x
H \ fx x
X 03 X <
X u
X X
z z z z
05 05 X X
X
II
X
33
X
H
<
X
O
X
H
X
X
X
X <
< a x a x
EH X
X Eh
x X
X <
a x <x
x x x <
D X X XX X
EXXoaX XX X
UE<Z<N<<CN<
< a u a u x u u a u
•73XXsJXxXcNQ;XX=-«xXNJXXXX=Ha < lXXX>>>>>>EX>>XEHXNaXX>'
3<<ZdX<ZOO< dX<Z0 3<<dOx<<c_»0300 0 0- : H<0 00 d<zaa - >
XUUdXXUdXXUXXUdXXUUOSXXUUXESSEEZXUEEXXUdXX^
X X XOX XX XX
X XX>>XXX>XC/3C/3HH< •—* CO CO > > *-*
<cN 0 < 00 <u< 00 aaxzxxaa 00 z
UdXUZZUXUZXXXX<r)XXXZE<
X
<
>
d
£h
a <
u <
H r*
O O
z z
X
X
X
X
<
Eh
U3
M
X
X
inioo T 3 ji a —i :n»** in
X>XDX>ODTiTiJ)J)T\J)
33333333333
-O r- oo>3—i.N' v ''rndn-3J
n3NJN J\333 3 3333 3
—t —I —I -H N N -N N N -N N .N N
333 3 333 3 3 3333
7 N 3 —t'l^'N-nvOr-- x>j\* 3 —in-'' Tin d h
3 —1 —I r-i -1 n-) r-\ —| —) —) —i .N N .N .N CN .N N N
•N CN M N N N N -N N CN N -N N N N N -N N N
333333333333333333 9
jo s ^ h .N 'f ji x>r- X)
r^r^r*)nn> nr) rr*nr>nr) nr) r*)rr)
N N N N N N N -N N .N N
333 33 3 33333
<J)
rn
CN
iNfo^iniONcoaiQHCN^fliiniONcojis
'T'rT’T^’T'T’Tininininmininininini©
CN .N CN CN CN CN CN CN .N CN CN CN CN CN .3 CN CN CN CN
3S333333S333333333S
3 3 3 3
x
—i n n "j
3 OJ -
X3 3 3
-h -h a
3 3
3 Ti
3 3
3 in
< a cn —i —i j xi —i _i -n —i —i a a on —i to ax x> r- j ) q i, <*» q 3 —1 o> a cn in
U U a d U u —I U U a d u u U a X U U dO^-ioo © d U in n Cj Cd U U x
i a 31 h a m
* a a o'
x^aNaxoQ<ao''naaNin
duuuuuuuuuuxuuua
©o>ux-N7id^ox.N^>crr-<ad—.w.
3333333333333333 93 3 333333
a a x » n- jy
33333933 933“
r-JOJiud3 ,v '©r-xxxX3'-i'Tn-X3>< auaxo-
d dc^-r-r-r'r-r-r'r' x> jo a© x x cox x x x x
1 * 1 * * 4 ’ .H H H H —C H H H
33333399
u u
a 3 3>—ijiacNinin—<a a<na , faaDafflHininHMNHinincNCDiD
din'n^ouuxx—<UUUXUininuMuf^QuQ3<X3(jX'd> v ©x
N"iriniD5i , jaLi]H'TN<cDU[KiS'*)ifNa)oi<!nu& ) (NiniON«oi
TtT.3>7\TiJ\T.C7\o\<<<<<<<mxXXXXfflXXXUUUUUU
•—I —I ^ —H-H—1-H-H^ — lr-tr-ii-^r—tr-)r-ti—)i—)i—)i—in -1 H H H H --1 —I r-i r —I H i-
93333393 3 333333333333333333 3 3333
Number 30
432
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 7
d
Id
CJ
<
-d
X
<
o o
CO E-* o
co a
cd as
-3 CJ Cd
Z Cd
2 m as
Cd 6-«
z - as
&■« h s
X X X Cd
MO z
CO m OS
o X OS Cd Cd
< £ X >
d 3 O H <
X 3 O O CO
it:
-d D M M
z ,h < u
< J
td S Z
J > M d Z
<<JZ O
: co vo — o
x z 3
Cd d X Cd 3
2 d x d x d cj < a £ x
COCO -*><02 X *• «* iH *
ma<MXXcQuoz<QQ*» a a q (j q t
z d x < < < a, x x <
O - - * O * C2 »
3CJ<CQeO<COXQxacQZXQa£CQCJX<XX
X X < < £ Of
XQcO<r-xacjcOxaa£ Z
X 3 CJ i
X Q X
J d x x d x d x x xx x xxx x x
^?y zz 22f £<i: 5 3<<Or-4ZOr-4003QOOZZaOOZOOXOd3 D^OZOQOOZZQDZUN'JZ^BOOOU
“irt.a.a..i«>«i MMa j X g raaiSOCaSOiaiaiS<ZJXClHMk:i(0p? Q 0 Q r70(oa|a|Q|tf
MOiOHHStUUTaid<<£SUJ4aUttOMSMiia ( 0| 1 4ts»
d z
O M
td
U Z J *
d
<
X cl u
cj z
CJ X
(H CJ
X X
d 3
Z CJ
m < M d
x u tH d <
CJ 3 'O X CJ
n m ^ in v
H H H H »
V W ■
a ■s s s '
> on -a -h a -r
i ,3 a rg rN <n
1 't T T <f f
> a a a a a
aaaaaaaa
i^»nn'Or'a3\sH.N^fin^r'«3\sH.N'*'>fin'fln-s3iSHiN' r !q , inior';
■ m m m m m m m *t 'f'TtTTT^r’T^ininininininininininiO'fixiiO'fiiOiDioi
''T'j’TTT'fTT <3-^r-crvr^r-5'»j'»3 , vrrj'Tr'T -r t •
>aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa-
i .n m ^ in in r' co
- r- r- r> r- r- r-
" 'T ^3* ^ 'J ^
) a a s saaa
Ijl 3 H .N T in lO
r- d co oo oo co n co
aaaaaaaa
a a a -N
a a a a
in a
a x>
a a -a
ms m *r m
S X as s
Q
Cd
on on 'T cj a Q a x
a u ax a < a —i
a
oo
x
a
a iO a o u -=r
-j a .n » J\ cj
(NH<' , im<fQg3Min<oiOa ( , BQHifiJiQQtN'»ioiN , ^Hin<r'r v rr' , ’<;r'inrMHU'Of^ : J"C' , c''no'D r '<
axQaa^» , '3'CJCJCj3'-iocdn—icj-icd—icjr^'sar^a'dQtd—i*rr^a33r--aCj , .dr^x'£>cjcd33P'-cdXM
'Oco^<iOMin<QcNar'HHH3<
'f.NHHJ'USuaUCOcOUQCdU
QMQX<^IONQ
aou^o^ou
xr^cocQcjQcdxanxoN<ocdX3«Tr'-'x>ONCjQ;dxa3a' , 'Nxj*nxr^.oooN<:Qcjxa33«Tm
UldiltdldUCdai-i.Ciji.a.iiCi.CuaaaaaaaaaHHHHHHHHHHHHHHNN.N.NlN
cvo-ic^c'ioir^.'^rvrvr^o^.^i 04 o-icsimmmmmmmmmmmmmmm. mm mmmmmmmmmmm
a aa a a a a aaaaaaaaaaaaaa aaaaaaaaaaaa aaaaaaaaaaa
iOM JUOUQd
.•N .a fN CN rsi CN ,-N .-N
'm rm m m tm rm <m , m
a aa a a aa a
X a 3 cm m x r~-
a m m m m m, ro
m m m m m m m
a a a a a a a
<ffiUCbSHINm
m m rm m *t ^ ^ ^
mnmrommfo'o
aaaaaaaa
■*rnoocaQ3~'*r
<f'i'r<f'fininin
a a a a a aa a
< d cj <
< > m >
CJ < Z d
y> d — < u
m j cj
d < < Cd
< 6* 3 J
> * o <
d Q Q d Q X CJ
d X d
d Si 3 d X X a
< 3 X < 3 O Z
UidUlQiT
I *
d <
X •-
< ~ d
- d
-* O 3
— M Z
cj — a
cj -»
— < ■—
— > —
Z r d Z
X Q
— < <
uuu
— 3 ‘d>-.<>—3
cjcjz><xu<zcj
----
X d
X Q <
< < >
CJ CJ Cd
d d d
d d d E-.
< < < r d
CJ CJ CJ X
X <
< > —
X CJ Cd CJ Cd
X d
3 >
d d XdddddO
d X d dddrddx
<X<:>33<<3<<U
CJ 3 CJ X X CJ Cj X CJ CJ X
Cd <
> >
< Cd
CO —
CO X <
Z OX
O X > -
cj a co cd eo
3
d d x a
X d X E-* d >
H < O d Cd X o
X U X X c-4 d z
o
CJ X < CJ <
d k
> X d ►
o o < «
Z X u c
U CJ X
M C-* M Q 2
3 3 3 CO
O O O XXX
X
a o
Z M
3 X
O id
X X
o. Cd
Cd X
I Cd o
> X £
: h
I X d
i X M M
O Z
I X Cd II
• 3 £ > ••
: z 3 < cd
i cd 3 co a
6-* X
< S>
dxcos
m £ cd a
z O Cd X 2
*CJ X * CO
X <C 6-4 X X CQ 3
Z X X d X O
< Z < ' ' < U
Z < £ CO CJ CJ <
ddd 3 X X 3 d X Qd dd
<dddE-4XCOCOXMdtSlt-tOXXe-'ddX>>dd
»<<<Ld 33OX<ZXX00CdX<£00<<
:OOUX£XXXdU3d XXXdCJ3££CJU
O £-<
6-4 3
< O CO
>
N O
X £
J CJ X 2
- * Q W
: d cj x
d x
> d CO
O < 3
£ CJ X
d X (O
d d X d Z d X
3 X •* * O - -
ZMQQUCJQCQCO<mX<
d X d X
dNCO>>dXXX><X>
<Z300<0ZZ05-*Z3
CJ3X££CJXMMZCOMZ
- B Jl S H a
*rnvor~ D^a^-ia'^'Tnar^oo J'arHa^'Tnvor^oocTi a-iam<finiOMD3>s
~ ~ * ~ »Tninninninninn.nv£>v£)vovov£)vovOv£>vOsDr^r^r^r^r^r^-r~r~r^r~x
rr*sr)^~r)rr.r*>mmmmm mm mmmmmmmmmmmmmmmmmmmm
aaaaaaaaaaaaaaaaaa
HaMviniOMosaHaro-fifiiOMsaiS'
\ui-i'i'i'i'i-i'i'i'i'iuCOXCO®COCOCO®COa>3l3'0\J'3'0\WO'3'a!
mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm ‘ ~
a a a -4 a a a
a a a a a a a
m a a a a
a u- x x a
<f «*ia
a a a
a
x
a
a
a a a
a a a
x on x CJ a on on
x a a nn —i <r «r
lO H id jn ON a
on a m a a n
on m cQ a
x a cq a
x ' 0 * r~- oi n
a cj co a a
3n—tQ^H-HaQOQONQmQoonQQ'-'-tQQ'B
03^HCJ3CdCJCJdCJCJCJCJCJ0dCJCJCdCjCJd
3—40Nn<C'TQ^3QCdQQ30NnnncQ'-HQar-t"^f—i^HON«COr^^QQQooa
OQUUaf<f[duU' , ’UUUUQUXM!NUU‘N[uOQUaUUi''fU(JU'0
ON
X
q n q a n
CJ x CJ CJ 3
QQ<H3roQa<3CJ
nCJQaar'aar^
xoi<Qa—lanaoajcd
nnnnxxxxxxx
a a aaaaaaaaa
aaaaaaaaaaa
xamasoiCQa—I'a*
xr^r^-r^r^f^-r'xxx
a a a a a a a a a a
aaaaaaaaaa
r-xoNOQcdXaf'N«Tn
dxxxxxxonononon
a aaaaaaaaaa
a saasaaaaaa
xxQaroxr^xoi<x
ONONON<<<<<<<<
a a a a a a a a a a a
aaaaaaaaaaa
idrH*rr-»ON<xcdM«3'
<CQiXCQCQCQcacQCQCJ(J
a a a a a a a a a a a
aaaaaaaaaaa
nxoNCjQCdxaroxoN
CJCJCJCJCJCJCJQQQQ
aaaaaaaaaaa
aaaaaaaa aaa
< (K) X S H !N ^ f l/l
Q3QQXXXXXU
aaaaaaaa a a
aaaaaaaaaa
Page 8
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Number 30
433
< < - <
H H' H <
: < z x <
: o x o £ x
xfn<a
x < .. *
X Z H X ■£ 3
N U IX N ^
n -3 O “J x
H x H H
X > X
X £ Z X
o
J ISJ < > X
< Z Q O Z
o 3 x s m
a: ja.x>
Z C E X O
h u n s
H
XH oQ
oxo
X OS co x
XSSXSXXSXXSSXSSQ S.2SX.2C0C0Q5.5CQ _2S.SQ 2 2XXXX 2 X 8 2'2XX2
QQQQQQQQQQQQQQQ QQQQQQQ QQQChQQQ QQQQQQQQQQQQQQi
1 cm no «f in vo r-
vO'OvO\Dvo^'i)r'r'r'(^r^r't^f^
jii/iifiiDifiifiininiAirii/iatinifiin
SSSS3S3SSISSSSCIS
r'-r^ooaocoGO;x)ooao:x>cococricj\<5>J'
inininininm-ninininininininmin
83S83S33S8888388
'fin^or'C03N3H.Nfnfl , in'cr'
0M^au3\0>3'SS«33SSS
i/iiniCi/iiCinvovDCvo o >o -o vo
38338338333838
CO^S.H.‘NfO^/l'Or'XJl3H.N' , <1
SSHHHHHHHHHHM.N.NM
-Q 1 p vO ^ vO -D iO vO ^ vD vO vO vO sO i Q
33 3 3333333333333
^in^MD^SHlNrCTi/lvOMD
[NiNMiNMCNfnmcn'nfOi'immm
kO > XMO'0-0>£^)>0<fiifi^^<0£vD
3 3 3333333333333
no CO *f no «f no ^ xT
33 3 3333 333
UUUU CO Q
Cli X CN Cii 3 3"> X CN CO V H Jl
<<Uj<i ( OM^vOHQ.N<r'n^a«HS
UQXU<uU®^UU'cr'iN3uU' N r'
■^•r'<CJX3'HCNTfr^<Q3rHCNrri'X>a\CJ
38SSSHHr|Hr|rHININ!NINMIN!N
333338SS333S33S3S33
3 if Q r-t if U, *T X no
s in ^ 'tf n 1 *r ■f ld
i—{ a\ s^‘HCi.'»irntN'nfnc\ivroa«»iHca
O O QST^STins^inS'T’TS'J'f
Qid^t ll H(Nfl'CMJ\<IIl Q U XHfO V ifi
tN|.-N.N(NfCrO'C'OrOfC"1'Cf^rn"1»rfq'’T
3333833S3S333S33333
in o> in -n Hin h in h in
<f «f vO >3" «f T 'T lD lT>
'XMJlOU.NiilHiOi/UJiNU'nUQ'J^Hi,
3N , <r<rs'rs’T3'rN i 'r3'3 , N , 'jsin'r
'T'r'T'T'ji/iicii/ii/iiniciifiiniriinin^iDio
^ if if f *f f if if fffffffffff
S3S8S33S3S3333S3883
■y\ —t*r rH.-N m o h h
f if f <f m m f m«f
mH'T^uU'n^fNf^ffcj'jinin^
fsn3f-f3f'rins'f'f3if^r3'fin
'£M)»<UQlXSM'Cf'Xl'I)JWDQ[i]3
vOvovovovoX'Oior~-r~r^r~r-r'~r~r'-r~r''X
fffff'ff'ffff'ffffff'ff
83333383833 3 3333833
f rr s "1 mrcrcmfimr'if'ii’ircsi'if'ir'l cn s no cn cn no no s
3 8 3 CO 3 3333333333X333 3 S 3838 3 8 X
C_) r- if 3 f Xin'f3Q.-H0N3XQ3 3 0'ir' if VO in f H I s - Cti X 3
■ji Q 10 3 m uMn3iaco<oiQ®35i<Q *f 1—1 a f h < QX8
.NQnJH3MnQ£0QtNQWQtNQfCQMHWQQ MCDQHCJNQ.NQQ(3\Q(NHOMn
OOOCNOQOXOOOOOOOOOOCNOOO UauQUUUUUUUUniuQ
r-<Q3Xfinxovox.'^inxcQXrH^'r'<Q3mrovor^<cQOxrNinxavcjxrNro
'nininvovovoi£>v£)vovovor^i^-r^r-r^xxxxxo>!Tia>inovcTiaN(TicTN<<<<<<xx
nononororor^nonOnonO'^nornnonononoronononO''OnononO''Onononononononononononono
33 3SS888383S88S8 3338SS8888333388388338
no no no 3 *f n> no no «f *f if no no x f
8333 8 3 83833 S 3 38 33
f Q <Ti VO CJ ao CO OaiTlU3'3'Ul® 03 0300 O X o 3
in Cd< r-H CTi CN if JltNO'J'^OO'IN <Xl no 3> CN X X "N f 31 rN
QCDQQlUQH!J'<IiJ3Q£Liai<CiJfn<ai r t<a<3'<ti]XX(J'<Ci3<<tnUSQ<M
OaoOUOQOi , '!i.OU<0«XO m XOmXO"’XQ<0' , lXOQ<XOOi , lX
ifr^xxxxc'jro'fr^(Ti<QMXCNj’fr'<oxiN^finao<xoQ3rNinx<T'XOXiN
XXXXXXOOOOOOOOOQaaaQQXXXXXXXXXXXXXXXXS
nonono''n<^rononononononorononononononorononononononO''OnononononO'"OnOi'OnorO'f
3333333333333 8 , 3833S8SS3S3383S83 3 33 3 333
Number 30
434
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 9
M
O
X
U
M
£
O
M
05
M E-*
X U
M <
X X
H
M
co X
< o
CO Cl,
X
(N. H
Z X
M
< X
X x
M U X
O Cl,
Cl, Cl, Cl,
o
o
3
o
X Z
as e-< h h
Z O Q
H Z 'J I
JUHU
•J X X
O
s
o
o
o
o
o
o
£
M
M
0
M
M M
Eh
X
£
X
II
X
o
£h
£h
M
Eh
EH
Eh
o
£
>
z
>
M >
X
Q X
m a a
<
Eh
<
<
<
<
<
<
Eh
O
<
M
<
X <
M
Z <
o
X Of Of
u
+
<
+
+
+
+
+
<
£h
M
X
X
X
Eh X
Z
Cd —
z
XXX
X
Eh
+
Eh
0H
EH
Eh
Eh
+
< MX
EH
<
Eh
<
<
<
<
<
<
Eh
+ M <
O
Of M
Q
<
X
Q
X
U
X
£
<
Eh X X
X
3 a.
X o
u
X
Z
X
z
a x
a
o x
X
o
X
< Eh U
Eh
X
Eh
O' O
>
Eh X
<
1—l
X
o
X
X
a
X
X
o
X
< M X
X
<
X
X
X
X
a, x
X Eh X
X
< X
X
Of X M Eh
3
M
3
X o
<
> >
X
z
z
u
z
z
u
z
z
u
z
U Z Z
z
u
z
<
z
z
z
< z
z < z
z
u z
z
M Z £ X
X
X
X
< X
2
s
X
U H
X
X
X
O
o
o
o
o
o
- *• o
o
o
O
o
- o
o - o
o
- o
O
- O < M
z
<
z
> z
X
X
X
-05
o
a
u
X
X
u
u
x u
3
u
X
u
X
X Q U
u
X
u
X
X
a
u
u
X u
Q U X U Q U
X U
Q U
X u z z
f-f
Eh
M
M M
a,
X
Q
X
X
X
X X
X
< x < z
X X <
Q
X
X
X
0 x 0
X
X
0
X
X
X
X 0
X
X
X 0 X 0
X
X 0 X
X
0 X
X 0
X Q X
X
X 0
X 0
X
X
X
X
Q
Q X
X
X
X
M
X
X
X
X
X
X
X
X
M
X X
MMX
X
X
M
X
X
M
M
X
X
X
X
M X
O, X X m X
X
X
X M X X
X
X
M X X X
X
X
X
X
X
X X
X
X
X
M
Q
X
M X X
X
> < x
X
X X >
X
X
<
3
X
<
u < u
X
<
o <
u
X < 3 X X <
< U X
<
3
X
X
< u < u
X <
o < u X < O <
U X < o < u
X < X <
<
< u
< u
< £
3
3
3
X
<
X
X X X o o z
ZNXOOO
3
X
u
a,
X
u
X
u
X
X
u
X
u
X
X
u
a,
X X u
u
X
X
u
a.
X
X
u
X
u
X
X u
Or U X X U
X
u
X X u
a,
u
X
X U X u
u
u
X
u
X
U 3
a.
X
X
X
Q
X
XXX
X £ <
*-H
n
X
X X £
X
•3 , invor^coa\SHCNm^irnor'coo\SHCNn'finvor'00(^SHtNrn^invor'coONSHtNnfl , in\or-co3iSHr'im^fin>ar'Coa\SH.’Nro^in>or^cO(j\SHM' ¥ i«i'invor'00
HHHHHHCN(NCS[N(Nrsfvi(NNcvi(»iro(»ifnrn'nrorornfl^<f<t<f^^^^tr<rininininini/iininiflifMO'0'avDvovO'O i £\CMor'r'r'r'r'r'r^r'r'M»oococococococooo
r^r-r-r-r^r^r^r-i^r^r^r^r-r-r-r^r^r^r^r-r^r^r^r^r-r^r^r^r^r-r-r-r-r-r-r-r-r^r-r-r-r-r'r-r-r^r-r^r^i^r^r^r^r'r^r'r^r^r^r^r^r^r^r^r^r^r^r^r'r^r-r'r^r^r^
s 'Si ■a s •si ssssssssssssssssssssssssssssssssssssssssssssss ass sssssssssssssssssssss
S S S
CO S CO s
S 'T S S3
s co s S3
«J* S <f s s s
00 S CO CO S3 S3
s
S3
S3
Si
S S S
T SVfOCOM
CO S3 S3 S3 S S3
CO
S 3
CO sO Q S
H >0 Q H H
CO lO ca 3 vO ’£3
(-" M CO S H rH
Cl, £3 Cl, CO 'T Q
»r h N <r in a
<r uoi
in CO Os
S3 S M CM
(S X < X
U
X
HQinnQ
h u a n u
XQXMQMQXMQinM
MUXcmUQUMCmcjMcm
QQXMQinMMQXQXMQMQXMQMQXMQMQXMQCMQQQXQX
UUUNUaMHUUOUNUQUU<NUQUHNUQUUNUNuUUUUU
QcOimninH(MNH[NO\HU'nU<<J'Hr-tCOtN
UUaUQfNcofNCNCNa Mr'<cocjCL,CJU r " tT '
05 (J Cl, S3 CO
CN CM CM ro CO
in in in in in
S S S S S
so r- < X X H CM
co co co co ro *3*
in m m m in in m
S S3 S S S S S
in ID <T> CJ Q S CO
t t <r <r in in
in m m in m in m
s s s s s s s
lO O' < Q S H
in m m in io io
m m in m m m
s s s s s s
r- < co m X cm
SO SO sO SO so so r—
m in in in m m m
s s s s s s s
m so as < Q s
r" r" r-- r~ r- co
m m in m m in
s s s s s s
h ^ m co x u a
m m in in in m in
s s s s s s s
ScoioaiCJGuCNcoiOf-
in m m m m m in m in in
s s s s s s s s s s
<QHXsco^rr-<Q
<<<<XXXXXX
m in m in m in m in in in
a asHCMimor'cecj'
axuuuuuuuu
m m in in in m in in in in
S3 S3 '-I S S3
a j h
3hH
U < <
O >
Cl, <
£h X
> X
U X
soa
X Cl, Cl,
£ Eh S
' > -
S X U X
s
Q
2 M J »—l
Q ^ X X >
Q X X X
X
Of
X J Eh
> <x
X OI <
X > £h
XXX
X H
O O
Eh 3
< Of
O
&h
X <
O
Z
X 3 C
X O 3
x z :
Eh X C
X X X EH X m
X H < < h X < X
X 2 C* Eh Z Z XZ
* «. » *■ > - ^o » o
X£X£X£XMXQUXXU
Q XX
5<m5<m5<mmXmmXX
Z>Z>Z>^' T ' —
M x M X M x
X
<
> X
X z
- W - -o
3UXXQUXXU
X z z
*o
O X
X Z
-O
< X X
X z z
- O O
X U Q U
< X X
X Z O
-O
x o X X
Q XX x o x o X X CJ XX XX X CD x m X X CJ X X 0 XX
mXmmXXmXXXXmXXXXmXXmmXXmXXXXmXXXXmXXXXmXXm
XXXX<XX<CJ<UX<0<UX<3XX<XX<CJ<U5<<0<CJX<0<CJX<35<
XXXXUXXU5<05<XUXU5<XUXXXOXXU5<O5<XUXO5<XUXO5<XOXX
3'3HN ,, ''Tinioi v ®3'SHMfOif/iar'®iO'aHf'ioM | inar'fflO'3HN'OM'inar'ao'SH!N'*''»in'or'coo'SH."Mco'»iniDr'»0'SHCMcoM , inar'®0'SHCNco
M'^TTTT^^^^^^^xininininintnininin£>£>£>£5£>£>£>£>£>£>r'-r--r''r--r'-r'-r-r~r~-r-cococoaocoooaoaocoaoa''05050505050''05a>05ssssssssssMMMM
O £3 £3 £3 sO £> £3 £3 £3 £3 £3 £) £3 £3 £3£) £3£3 £> £)£> £)£)£3£3£5£3£3£3£3£)£3lO£5^£)iO£3£3£3£3£3£3£3lOin£3lOlOiO£3£5iO£)£3£3lO'sO£5£>'nr~r'r^r~r^r~r~-r~l— f" I—l~~
sssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss
s^r^rss 'T s s
CO s co CO s cos s
'T s
00 s
s s ^ s s ir s
S CO S 00 00 S CO s
s s
S CO s
H N O' CO
•o 1 in ^ in
S S S S S X X
S S3 S3 S S < Cl,
Cl. S
Cl, S
S S r- 3 £ co £3 £3
T S CQ 50 S M CO >—l M
i—i so
SO M
■T 3 £) —1 £3
in s rH a> i—i
< so
in rH
CO
'T
U r- s as u ^ ir>
IT S iTUT T /) 3
CO co ^
in it s
i/'Hi/'rHSO'SS
*r^s<rinmss
S3SSH>M£C0£)O£3O£)H(NH
SSSSrSINcOiNcONCHMcOININN
QinHQaQfflHQHQfflHQinH
UMiNuauuMuQuMNuaM
Q in rH Q X Q X
u a m u x u m
QrHQXrHQrHQXrHQin-H
uauuiNuQuu.Nuu^
fM O t £ co <;
00 CO CO CO 00 CO
M 1 T 'T T M 1
s s s s s s
X u
00 CO
s s
XSrHfN<r£>r^o\xUQX|Xsrsj«a , £>05UXCL,rHrM'srinr^-
a>asasasasasasasososasas*c XXXXXXXXUUUUU
SSSSSSSSSSS 3 ssssssssssssss
<QSCOVOI—-kCQMMCM
uuaaaaaaacdM
SSSSSSSSSSS
inDCMJQSm'Jh<QU
aaaaaaaaaaaa
ssssssssssss
s
in
s
s
m
s
in oo on cj
s s s s
s s s s
a.srorrf'-
SHHHH
in in in in in
s s s s s
< X CO Cl, CM
HHHHM
in in in in in
s s s s s
in £3
CM CM
m m
s s
Page 10
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
435
u
OCJ MUUUOCJOUU
CJCJi-HH-t Smihmmi-hhhmm
ZZOOmHOOOOOOOO
OOE-*H£<H^6-*H6-'HHEh
E-*6h<<0.+ <<<<<<<<
<< + + 6hH + + + + + + + + CO
+ WQS JJU
sjiH.N«j , i/ir'»sH' y i'f\or' 0 \s < < cn jn^'i'Hr^QscUMjvojwaiNU^Jco^H co £ z q as < as O <-3
HH(N(N(Nf'irM.-NfOmfOfnm«ir»ntJ«^a:inzcoOH<HCi.HQMQtNJ[ND(>JH' r iO' ,1 C^J , J'K os Z ox I Ct< Q Q J X X X M CO <
i,i,£i,iui,a4!i ( !i l [iiCu!i,Ct.[i 1 CiH(i,Ct.HH<CL 1 QCt,Oti-e-'CuOCv.CiJCt.<li.<ti.3ti.OC»-<^COCL,>Ci J a J i < < Q Q H O >N (d < < Z> rH Q "N < CO >
<<<<<<4:«i<<<:<<4:<<zucu<u<<<u<Q<u<u<z<cij<a l <«{<[d<<<UHUHU'N<®u»QHU-iUHzcoucoii,^<Na
X
a,
a.
< ~t
2;3 2 2232223S3222322SS2SS23223S22333SZ2ZZ2S233:
QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQaQQOQQQQQQQ-
X'H^rr^-srncoj* 3fnioa>cNinao.-i*rr^3 *h r- 3 ro vo cn m in xj »h
r-t cn in (N ro m m m rH ^•r*i-ipH<-i'HrMC'imrorom^ , f>iin®<H^H^Hr'imc>ic'irororo
CliCliCiiCz^IxiCliCliCli Cn CtiCnCnCtiCnCuCHCLiCLjCnCHCnCiiCuCnCnCnCnCnCijCnCnCijCuCnCn Cn
<<<<<<<<<<<<<<<<-<<<<<<<<<<<<<<<<<<<<
(NroTrinvoi x -coo'SH!N"i'j , LOtcr , 'OOij\(aH^m^Lncor'XONSiHC'i' y i^Tinvof > '00o'QHfNn^ , invor^oo^®H<N' r i^'iO'or^ooj\iaHCNM<j'mvflf'30(yNSH.Nfn9'
voi£iyovoiovDvo'or'r'r'r'r^r'r^r'r^r-oocococo33cococococoffio>OMj»OM3>a\(j\o>a\sssissis®aisiiaHHHHHHHHHHr>4cMCNCNMCNiNM(N.NMfnfOf»iro
:»xco»a3cocoaococococoaoaoaoxaoa3aocoao3ooao»:ococox3aocoa3coajxcoxcna\nnnncncnnnnnn^a\^nn^a\cntna>(na>nncnnncn(ncn:n'n
33S3333S3333333'S>® , S>SS3333S333333333333333333333333333S333333SS3333S33S33S3
iOvOmi 0 iOvOl 0 iOV 0 i 0 vOiOvOiOlO^OS ^•vO^ , iOxriO«J , iO^ , iO^’i0^fiO^ , iO*J’lO«a , lO 'rvDfl'iOf'D'T'DSS'aSSSSSSSiriSSSSSSSSSSSHS —I 3 rH 3
3333333333333333COCO30O3CO3CO3CO3CO3CO3CO3CO3COj2COiSCO3CO3COr23333333333333333333333333333
Cuf''»liar'Ci 4 CQ' v 1Ci J r'f»>cDr'Ci J cO rr i®'0( s '<;cO' T 1CL4Hi»lli < r'OOfflQCL<fOfOOOr-QCD' v 1CL4ffl' y 1Hr x vOCQ^H®H'OMCQHHMCuH' r lH^£>Ha'HmCN!nrovO(NU‘'NvD<»i
'Tcoina3incoin(^ini^ioa\voa\^<isro<rn <I ;rr < j;rocQ^cQ»rcn^(iir'Ur s U^U co U®Q | 3'Q 1T 'Q'SiSHSHSfN®rococi J sssss'J , cocQcou'SHS' r isiais
QCL,Hnmr'j-cQQii ( Hninr'(jMiiQCL < Hroinr^(TicnQ(i J Hfninr'aicQQu,Hrninr'^cDQCi < Hroinr^(j\cQQCi.Hrnuir^aMiiQCi,Hrouir^!j\mQCL,H^inr'(^£iiQ
xrx*ininininininininiOinin\Ov©\ninior^r~r^r^r^r~r^r^3®OT®ooaoco®<n<n(n^<n<n<n<n<<<<<<<<:cQcacocoxcQcQCQCJ(JCJUOOCJCJQQQQQQQ
COCOVOVOVOVOVOVOVOVOVOVOVOVOSAVOVOVOVOVOVOVOCOVOVOVOVOVOVOVOVOVOVOVO^OVOVO 'O'O'DvO'OVO'O'OvO'DvO'O'O'O'O'O'O'O'O'O'O'O'O'OvDvO'Ofi'O'O'O'O'O'OvO'O
3333 S3333333333SS33333333 3 3333333333 3| 333333333 S33333SS333S3333S33 33 3 3 3333
m in m m in in in ^ in 3 3 3 in co s 3 s 33 'T 3 3
33 333 3 3 3 3 SCli3 333 3 3 3S333S 3
3 <£ CTi i—I <C 3 O CJ CN Cn 3 0"\ 3 Cn CO T\ vO <T> vO «3* VO V 9llO>CiC'CiO'£lOiClOvOiC
Q CQ Cd Cn CQ CQ Q Q 03 Q 3 ^ --I Cn -H I— t 3 3 3 rH CQ >— I CQ 333333333333
S <f'OWNfo<<CKinoMB<oiHHHCQaincNini , ns<H<aiHinrom QcomQQmQoicncOQHWQinin<fQQcDQQcD<;aQNHHm!i J com[i J M^£iiM<cQco
Q''J , r~-cj<ncjQ'TCJ3WCNCnW(JCnMU ( ^'Q'S>UCnUCNCnUOUU CJUMOUMOUUMUQOCJWQininCJUOOMCNCdCJcNQCdCji£)ror'cnr-'» , r^«a < r^^cO
<QSH(Nin'OtjiuQU^ | s ,T ’ , > , inior'»ij\<QUHfN<viior s -co3iU£ijCi<'N'»i'fr'<cQCdCKiaH'finiO(j\<cQUOSH»fr'»cncj&<N(»i'irc^a\caQCx J Hf , iin(^o\cQ
UUQQQQQQQQQQtdti3MCdUUtdIdCdUUai[L < Ii J Ci,Ci.[i-Ci<CnIuCiiSSlSSS3SSHHHHHHHHHH(NCM,NMr'ICN^(N'*imwmmf«irom^'T^'I'T'J'
inininininininininininininininininininininininininininminininininioioiO'Oi£>'Oioio>x)io-oioioioiovoio^ioioio^'Oii5iO'CioioioioioiDioioioioioioioiD
3333333333333333S3S333333333333333S3333S3S3333333S 33333333333333333333333
Number 30
436
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 11
A Curve-Fitting Program Using
a Focal Interpreter on the KIM-1
BY THEODORE E. BRIDGE
54 Williamsburg Dr.
Springfield, MA 01108
I have three reasons for writing this article. First I want to
report on my experience with the FCL65E interpreter that I
purchased from the 6502 Program Exchange, 2920 Moana,
Reno, NV 89509:
Program (HYPERTAPE on cassette) $19.00
Mini Manual 6.00
User’s Manual 12.00
Listing 35.00
Total $72.00
Not being able to locate a suitable BASIC interpreter for
my KIM -1,1 decided to give this a try. My first project was
this curve fitting program. I believe the FCL65E interpreter is
more compact than BASIC, possibly a little slower, but quite
adequate. It has excellent diagnostics. It even has string func¬
tions.
My second reason was that I would like to see a BASIC
version of this program published in DDJ, hopefully with a
timing comparison. With my program, it took 40 seconds to
calculate the regression coefficients in example 1 with six
degrees of freedom, and 16 seconds in example 2 with four
degrees of freedom. I think there may be many readers who
would like to have a BASIC version of this program.
My third reason is that I want to donate this program to the
public domain. It is very handy if you want to read data from
tables or curves, or even if you want to make sense out of a
large mass of test data.
I once used a FORTRAN version of this program to analyze
a large block of test data on the performance of a very big
centrifugal pump. None of us could make any sense out of the
data, but the computer could. It showed that the efficiency
peaked at the end of the first month, and then started to fall.
We were then able to optimize the maintenance schedule on
the pump. You could use a similar program to optimize the
spark and throttle setting on a gas engine as a function of
speed, load, and temperature.
In the listing, I present a FOCAL program for finding a
formula that will relate a dependent variable, W, to two inde¬
pendent variables, X and Y. When we say W = /(X, Y) we
simply mean that the variable W depends in a definite way on
variables X and Y. For any value of X and Y there is one and
only one possible value to W. To make this analysis, we assume
that a polynomial equation can be found to express the
relationship.
We will now consider an example having 3 degrees of free¬
dom (a parabolic fit) with respect to X, and 2 degrees of free¬
dom (a linear fit) with respect to Y.
The polynomial equation will look like this- W will be the
given value, and V the calculated value of the dependent vari¬
able:
V = C(0) + C(1)X + C(2)X 2
+ (C(3) + C(4)X + C(5)X 2 ) Y
So you can see, if we knew the coefficients in the array, C,
we could calculate a value of V for any combination of values
for X and Y.
Our first task is to find values for these coefficients that
will give a minimum error. Since there are 6 unknowns in the
array, C, we will need 6 equations. These regression equations
have been developed in the science of statistics and are not
hard to program. We will express these equations in matrix
form. For each data point (one value of X, Y, and W) we will
develop a correction to be added to the matrix and will collect
the total in array, T.
We will build the first row of the correction matrix in array,
U, and each of the following terms will represent consecutive
elements in this array. There are 7 terms representing this first
equation. The last term is the given value of the dependent
varaible, W. Thus:
U = 1, X, X 2 , Y, YX, YX 2 , W
Using the following algorithm, we will build the regression
matrix in array, T. It will have 6 rows and 7 columns. We
initialized array T = 0. For each data point, we will update
every element of array T as follows:
T(I, J) = T(I, J) + U(I) * U(J)
I varies from zero to Ml, and J varies from zero to M. Let
XI = the degrees of freedom for X, and Y1 = the degrees of
freedom for Y. Then M = XI * Yl, and Ml = M — 1.
We must have at least M unique data points—as many as we
have total degrees of freedom. That is, at least one data point
for every row in the matrix T. The more, the better. After all
data points have been processed, we will perform a Gaussian
elimination to solve the simultaneous equations for the regres¬
sion coefficients.
Page 12
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
437
This program was written in FCL65E (FOCAL) for the
KIM -1. FOCAL is very similar to BASIC:
D for (DO)
in FCL65
is
like
GOSUB
in
BAS
C ” (COMMENT)
REM
**
»»
F ” (FOR)
»»
FOR
»*
G ” (GO)
»*
n
»*
GOTO
»»
»>
I ” (IF)
»> »»
»»
IF
S ” (SET)
»»
LET
>>
>»
T ” (TYPE)
»* »»
PRINT
»*
A ” (ASK)
»» »»
i»
INPUT
>»
»»
The DO statement in FOCAL assumes an implied return at
the end of the line (i.e., D 6.8 in line 5.7 of the listing); or, at
the end of the group called (i.e. D 3 at the end of line 7.1).
However, a return will be made whenever the command R is
encountered. The FOR statement in FCL65E assumes an
implied NEXT command at the end of the line.
The IF statement in FCL65E is like a FORTRAN II IF in
that it cannot handle logical operators. Rather, the expression
within the parentheses is evaluated. A branch is made to one
of three line numbers that follow the closing parenthesis,
depending on the value of the expression. It branches to the
first line number if the expression is negative, to the second if
it is zero, and to the third if it is positive. If any of these line
numbers are missing, control drops through to the next
instruction.
I believe that the comments on the listing and on the
examples that follow will complete the explanation of the
program and its use.
0X2
U, F- O
U. —
U to
P _4 01 I
a H X I
_> u;
X 01 P <
X I
Ul o
0, F- I
>• ui h ;
X 04
Inti
h u. o ;
•• v, ,
ri5ui:
04 it >
W u j I
X O O l
; to
u x
w o ,
cu ui h ;
x x
H H 2
O
03 O
04 vX
L- uJ
<Ul3l
11 <2
>-
£
F- F-
H
H
—
*
>r
2 •*
2
X
^ U:
>
ii
<
« P >4
X
•
u
ii
<
VX
o o; »-t
O
J
o
CU
CM
CM
H
X
X X X
X
3
CM l
CM
>-
0) CM
CM
D
••l
X H
p
X
1
II
#
O
—
< <t
X
X
P 1
o
CM
— CM P
P
X
1
h Vi E
o
2
<
M*
s
• CM
II
<34 -
P 2
a
□
>
X
o
m
p-
•**
CM P CO
01
II
M
<C O
F- %
in
01
X r' ■' u
w
■*
<00 H
X
o p
J
J
<t
O
ii
i n a u
4*
—
01
< 01 w -- , ~
(4 Q i/i Ui U U J P 03 H •
o UJ x _J O — CM CO
0,00 04 .1- — J Q W _J • It
m O 1/1 II .^hQnO OusUJ-Q
t'
H □ O-sJ.'O — CO
<t . -• P It II II II II II U II 1
2-"OUUJ>>^0^5» X . —
W ^ X
q w \o u, di - cm ca — cm si in o; — —
04 > U. X II It II II II II . 0J — — VI
004 0JEXXXXXX CO X — — :
O Z-> O O
O U O U O VI W Ui W l/i Ul OOHH0J0, w Ul F Q O Q
UJ —
^ >-
Cu >
X CV1
XW II
~ <*> 2
CO II
N N •
+ ♦
2 -
II 2
— II
2 2
X U,
CO CO CO
— co in i
o ca co i
} CM <s ts
« CM CO
M <T
II •
M X CM
CM
to : ^
— M
cm : w
CM H — 04
CM
^ 00 s CO
N II *11
wm: w
m ul F Ul
CiSCUCItJCllSSC>i5iCi;
Ol & S Si ^
CM CM CM CM CM CM
CM CM CM CM CM CM
SI 81 81 £1
J — —
U Ui
X J
U Ui
co tC
UJ u!
■» >
r- — o
<z o -
■ 04 2 l
! o. uj 'ii
o J -
i u, u : :
• T. < -
; SSi
ui : —
•03 •» X
■ X — ||
» x — £
‘3 .*
II CO
«S> CM
Cl Pi
CO *
• Sj
CM I
co *o
X - |
Z Cl CM
h “J M
X <
— X
H •» ^
O —
O O —
U C-
Ci Sj
ul O \
U Oj —
- II II
. CO CM
i “0
— CM Ui Cs.
C* — CM CO
►« CO *0
0J ^ +
Ul H H
O “S ■»
2 I —
3“ A
o |
11 : to
2 H Cb ‘
^ C> <T ■
H . ~
2 ^ tj I
X cm i i
X • ■
o ^
F- <3 h
I
O 01 I
X y
, *
wj :
II x
h3 :
•» %
— -o
Z V F
O • *
-» — <r
i*
U t. — -M Csl
2 II I II •
— =0 — —
x n
— *
X “3
t— ♦
< —
T. II
j r.
— «\
U Ck
C 5- X X
II X P
i Gj ed
I t" ox
i 01 O X
i lit P- O'
II •»
— Cii
II
X o
X •«*
— X
II
— —
l- 0j H
r~ o
u . ...
Ul O ^
F « Z'
2X0
— I +
X — u.
— -c
O — i_
( 7)
2 X
X X {-
•«* H II
i/» X <
<44 •» :
CM 2
II x * c
O W^l
H II l
U. 2X1
- X C
0, l
X 01
h I
W X (
— X *
2 < (- i
^ t
O 01 X I
F* l
U -Pi
II X I
— — — U II
o x
X ~
F-
o ■*
H 7)
O 2
*-! S
X O
X —
O N
P -
o X
o ^
■* t-
X II
ui co :
H
J p
4lJ ‘
tl
X *
04 P
H
<J! 0i
J
H y :
t. s
t- — ;
n
u *o C
ci x t
<14 CM <
F- 2
+
: uj
•» 01
2 X
■* II
— <
H ^
>-
: o o —
* ”0
•• VI u w
t. o
x II
u. >
U 0)‘c
O' o <
X X
II t
CM <T
i F- 01
. CO 04
I ti
X
II II
. O Cil Ci
1 F CO O'
o — — — —
CO Cl co co
<X •q 1
ui ui in ui ui ui in i/i w >o no vo o r- c— c— t-~ r- t-~ ijocococoeocnwccicococo
Number 30
438
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 13
EXAMFLE MO- 1 6 . f FrPCrEC 6 . PPPPBFF 9 .PrPPPFP 9 .feefEEC
The following magic number was typed by the program just to
let you know that something is happening during the long wait. l.EPPEeEC A. PECCPEC e.CCECCEC 6 . FeCCeZC
u
o
n
<u to
C 0)
CD
I CO
CO Ul I O'
I CO CD Ul I
k ol i O | U) W
o Cji uj ci uj n co
k. C- c— O -j Cv l/)
Cu Cl —• C*- vO C~ Co
Ul <7 in . cO <7 i/>
O' O c\l O' • ■'I
. CnJ | — <7 .
CO • . I t"
I C»1 — CO I
I —
UC.tiku.wO
J UJ ul U U (J U
C. ^ iy U U O
O u CJ O Ij C> L
Cil Cii Cm Cu Cl <7
li. CJ U) CJ - V
Cd tw • Cd • C-
• • r~ • — .
CO -7 NO CO
w-s Csi lii | Co Ul Cd
U uj uj W U
C- O U t< li o
C. U O L. li U
u ul u b O N
Cl ill Ul t» ml vO
U id Ul Ul • t~
u
J-C.t-t-C.ulC-
w U Ul ui (j Ul
u t Ci O U U
Cu O C C <d t
U Cl U u o c.
U O C. C. C. C.
U< Cl Ui C. • n_
• • • • to •
— —• — CO VO
to
t C C Cl ui c
Ul Ul Ul Ul C- Ul
uiCCCCu
UuCulCU
(.UiCiutiCi
ui u Cii U C. ui
Nil C* Co Cal • CO
• • . • Cm .
— W Ul - N-i
- w n <f iti no
ul
to
Cl
Co
Ci
to
u
o
u
u.
ul
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
439
Binary Tree Manipulation
on the 8080
BY MIKE GABRIELSON
Box 2692
Stanford, Calif. 94305
Imagine that we are writing a compiler. How should the
symbol table be organized? One possibility is to use a binary
tree. Figure 1 illustrates a binary tree that contains seven
symbols (strings representing variable names). Each symbol
is contained in a node along with two pointers. The pointers
are used to link together the nodes of the tree. A special
pointer called the root points to the topmost node of the tree.
(Computer trees grow upside down.) Grounded pointers on
the bottommost nodes have nothing to point to.
On the 8080 and similar computers, we can let each pointer
be a 16 bit address, and each symbol can be an ASCII string.
Figure 2 shows a portion of our tree as it might actually be
stored in an arbitrary region of memory. By convention, we
will set grounded pointers to a zero value, and delimit each
string with the NUL character. An actual symbol table for a
compiler would include some extra bytes in each node for
flags, values, and other information about each symbol, but
we’ll ignore that to simplify the examples.
Number 30
440
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 15
IOZ2
The symbols in our tree are arranged in a special way:
if we pick any node, we find that the left pointer (if not
grounded) points to a subtree containing symbols all alpha¬
betically less than (preceding) the symbol in the node. Simi¬
larly, the right pointer points to a subtree containing symbols
all alphabetically greater than (following) the symbol in the
node. Maintaining the tree in this ordered manner allows us
to design very simple but effective algorithms to manipulate
the data in the tree. For example, suppose our compiler
needs to look for a symbol in the tree. How should the tree
be searched? Starting with the first node (pointed to by the
root), we compare the node’s symbol to the symbol we desire.
If there’s a match, we’re done. If our symbol is less than the
node’s symbol, we follow the node’s left pointer and repeat
the test with that node. If our symbol is greater, we pick the
right subtree, and so on down the branches until we find a
match or until we reach a grounded pointer, which indicates
the symbol is nowhere in the tree. The sample subroutine
called SEARCH will search a binary tree like ours using this
algorithm.
1 ; SEARCH - search symbol tree for an ASCII string
2 ; Mike Gabrielson 8/10/78
3 ; accepts: BC = address of string to look for, terminated by NUL
4 ; DE - address of ROOT pointer
5 ; HL = contents of ROOT pointer (equal to address of
6 ; first node if not grounded)
; returns: carry set if string not found in tree (DE ■ address
8 ; of last grounded pointer)
9 ; else carry cleared (string found, HL * address of
10
1
node
containing the matching string)
12
13
14
15
NUL - 0
,-end of string character
0000
7C
SEARCH:
MOV
A ,H
,-is the pointer grounded,
16
0001
B5
ORA
L
indicating end of tree?
17
0002
37
STC
; (assume "yes")
18
0003
C8
RZ
;yes, end of tree, string not found
19
0004
C5
PUSH
B
;no, save address of caller's string
20
0005
E5
PUSH
H
.-save address of node
21
0006
23
I NX
H
;skip past the node's
22
0007
23
I N X
H
,-left and right subtree pointers
23
0008
23
1 N X
H
,-and stop at the first character
24
0009
23
IN X
H
;of the node's string
25
0 00A
0A
NEXTC:
LDAX
B
;get character from caller's string
26
000B
BE
CMP
M
.-same as character in node's string?
27
000C
C21600
JNZ
TESTED
;no, wrong node
28
0 0 0 F
03
I NX
B
;yes,
29
0010
23
I NX
H
.-point to next character pair
30
0011
FE00
CPI
NUL
;was that the end of the strings?
31
0013
C20A00
JNZ
NEXTC
;no, test next pair
32
0016
El
TESTED:
POP
H
.-restore address of node
33
0017
Cl
POP
B
.-restore address of caller's string
34
0018
C8
RZ
.-done if strings matched (carry's cleared)
35
0019
DA1E00
JC
LEFT
;pick left subtree if caller's string is low
36
001C
23
INX
H
.-else get address of right subtree pointer
37
0 01D
23
IN X
H
38
001E
56
LEFT:
MOV
D, M
.-get address of subtree into DE
39
0 01 F
23
INX
H
40
0020
5E
MOV
E, M
4 1
0021
EB
XCHG
;then into HL
42
0022
IB
DC X
D
.-leave DE pointing to last node accessed
43
0023
C30000
JMP
SEARCH
.-continue searching down the tree
How do we grow a tree in the first place? One necessary
ingredient to grow a tree is memory. Let’s assume we have
access to two new pointers. One pointer is called FIRST and
is the address of the first byte of a contiguous chunk of mem¬
ory available for the tree. The last available byte in the chunk
is pointed to by LAST. This arrangement is illustrated in
Figure 3. Each time our tree needs a byte to grow.it can grab
the byte pointed to by FIRST, and then increment FIRST.
Memory is exhausted when FIRST passes LAST. Now we can
modify our search so that when a symbol is not found in the
tree, a new node is automatically grown for it. The next listing
is a subroutine called LOOKUP which appends new symbols
to the tree as necessary. (To simplify the code, this version
of LOOKUP does not check if FIRST passes LAST, indicat¬
ing memory overflow.) An example of a call to LOOKUP is
LXI B,STRING ;get address of string
LXI H,ROOT ;get address of ROOT
MOV D,M ;get contents of ROOT
I NX H
MOV E,M
DCX H .-restore address of ROOT
XCHG ,-adjust registers for LOOKUP
CALL LOOKUP
The calling sequence can be simplified if the contents of
the 16-bit root and node pointers are maintained in standard
Intel byte-reversed format, instead of unreversed as the code
currently requires. Changing the code so that all pointers are
byte-reversed is an easy exercise left to the reader. Figure 4
shows how the tree has grown after a LOOKUP of the symbol
THETA.
Page 16
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
441
1
2
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20 0000 CD-
21 0003 D0
22 0004 2A-
23 0007 E5
24 0008 EB
25 0009 72
26 000A 23
27 000B 73
28 000C AF
29 000D 12
30 000E 13
31 000F 12
32 0010 13
33 0011 12
34 0012 13
35 0013 12
36 0014 13
37 0015 0A
38 0016 12
39 0017 03
40 0018 13
41 0019 FE00
42 00IB C21500
43 001E EB
44 001F 22-
45 0022 El
46 0023 37
47 0024 C9
LOOKUP - find ASCII stcing in symbol tree
Mike Gabrielson 8/10/78
accepts: BC » address of string to look for, terminated by NUL
DE ■ address of ROOT pointer
HL * contents of ROOT pointer (equals address of
first node if not grounded)
returns: HL * address of tree node containing the string
carry set if a new node had to be grown
else carry cleared (symbol already in tree)
MEMORY OVERFLOW IS NOT TESTED FOR!
NUL * 0 ;end of string character
!EXTRN SEARCH ;SEARCH is not defined in this assembly
!EXTRN FIRST ;external pointer containing address of
;first byte of available memory for
;growing new nodes
LOOKUP: CALL SEARCH
RNC
LHLD FIRST
PUSH H
XCHG
MOV M,D
INX H
MOV M,E
XRA A
STAX D
INX D
STAX D
INX D
STAX D
INX D
STAX D
INX D
SAVNAM: LDAX B
STAX D
INX B
INX D
CPI NUL
JNZ SAVNAM
XCHG
SHLD FIRST
POP H
STC
RET
.•symbol already in tree?
;yes, all done
;no, get address of node about to sprout
;save address of new node for return
;HL :» address of last pointer SLAKCHed
;replace grounded pointer with address
jof new node
;clear register A
;and grqwnd the two subtree pointers in the
;new node
;get next character from caller's string
;save in new node
.•adjust pointers for next character
;was that the end of the string?
jno
;get address of next available byte into HL
;save new FIRST
;yes, restore address of new node
.•indicate new node was grown for caller
A nice feature for our compiler would be the capability of
listing the symbol table in alphabetical order. How can we list
our tree? Because of the way the tree is ordered, one elegant
algorithm we can use works as follows: before listing any
node, first list the node (subtree, if any) pointed to on the left,
then list the original node, then list the node (subtree) pointed
to on the right. Start with the node pointed to by the root,
but always try to first visit the left subtree at each node.
This is a recursive algorithm that is easy to implement on
machines with a stack like the 8080. The final sample program
is a recursive routine called PUTREE that will dump our tree
using this algorithm. An example of a call to PUTREE is
LHLD ROOT
MOV A,H
MOV H,L
MOV L.A
ORA H
CNZ PUTRE
;get contents of ROOT
;swap H and L
;to be consistent with
;rest of tree
; is root grounded?
;no, output tree
A way to visualize what’s happening is to imagine an ant
visiting each node by crawling around the edges of the tree
(see Figure 5). If the sun is shining from the upper left, and
the ant shouts out each symbol the first time it crawls along a
shaded side of the symbol’s node, then the symbols will be
shouted out in alphabetical order.
PUTREE - output symbol tree in alphabetical order
Mike Gabrielson 8/10/78
accepts: HL = contents of ROOT pointer (must not be grounded)
9
10
! EXTRN PUTNAM ;this is an external routine not
jdefined in this assembly. PUTNAM
.•outputs the ASCII string addressed
;by HL (which must be saved) and
.•terminated by NUL.
11
12
0000
D5 PUTREE:
PUSH
D
.•save pointer to the pointer when
reentered
13
0001
E5
PUSH
H
;save address of node
14
0002
56
MOV
D, M
;get pointer to left subtree into
DE
15
0003
23
INX
H
16
0004
5E
MOV
E, M
17
0005
23
INX
H
18
0006
EB
XCHG
;then into HL
19
0007
7C
MOV
A,H
;no left subtree?
20
0008
B5
ORA
L
;(pointer grounded?)
21
0009
C40000
CNZ
PUTREE
.•subtree exists, traverse it now
22
000C
EB
XCHG
;restore address of original node
to HL
23
000D
23
INX
H
;skip right subtree pointer
24
000E
23
INX
H
;and get address of symbol name
25
000F
CD—
CALL
PUTNAM
joutput the ASCII string
26
0012
2B
DC X
H
;get node's right subtree pointer
into DE
27
0013
5E
MOV
E,M
28
0014
2B
DC X
H
29
0015
56
MOV
D,M
30
0016
EB
XCHG
;then into HL
31
0017
7C
MOV
A ,H
;no right subtree?
32
0018
B5
ORA
L
;(pointer grounded?)
33
0019
C40000
CNZ
PUTREE
.•subtree exists, traverse it now
34
001C
El
POP
H
;restore stack
35
001D
D1
POP
D
36
0 0 IE
C9
RET
Number 30
442
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 17
PROGRAMMING
LANGUAGES AND STANDARDS
BY DAVID CHAPMAN
Western Reserve Academy
Hudson, Ohio 44236
Over the last few years, the tremendous proliferation of
microcomputers has been accompanied by a growing reliance
on BASIC as the “standard” high-level language. Nearly every
microprocessor has at least one BASIC available for it; the
8080 must have at least a dozen. This is an undesirable state
of affairs for a number of reasons, not the least of which is
that BASIC is an atrocious language. Some people have there¬
fore suggested that some other language should be made stan¬
dard; but this is not the solution.
Flaws in BASIC have been written about elsewhere 1 . The
language has only three datatypes (rel, array, and string),
only the most elementary control structures (GOTO, GOSUB-
RETURN, and FOR-NEXT), few built-in functions, and only
the most primitive function definition facilities; it supports
either no files at all or only sequential files, and so on. “But,”
you say, “surely all these deficiencies could be corrected by
relatively minor modifications in the language?” Yes, some
could be and have been. The result, however, is often some¬
thing that is not quite BASIC, which is supposedly a standard.
This is because most of the language’s problems arise not from
semantic difficulties (lack of random-access file capability,
for example) but from fundamental syntactic problems:
verbosity, verb richness, lack of structure, and a general lack
of thinking through. BASIC was, after all, designed as an
educational language and as an improved FORTRAN-not
for applications programming.
The obvious (though mistaken) thing to do is to replace
BASIC with some other language as a standard. Of course,
this would mean some revamping in the microcomputer
industry. This might not be difficult, as most of the manu¬
facturers suffer from advanced, chronic bandwagonism: every
time any one of them comes up with something new, it is
immediately copied a dozen times over.
This bandwagonism hurts everyone: the innovators have
their ideas stolen; the bandwagonists must compete against
many other companies making an identical product, and the
users get little freedom of choice in buying their computers
and accessories. Bandwagonism has also tended to establish
standards, most of them informal, incomplete, and harmful.
The S-100 bus, established simply by its use in the Altair,
the first computer to be produced in what were then large
quantities, has an excessively large number of lines, many of
them undefined or multiply defined, and uses expensive
hundred-pin connectors. 2 The Kansas City standard cassette
interface, by now more or less abandoned, was slow, ineffi¬
cient, and error-prone. 3 Various other cassette “standards,”
for example the CUTS system sponsored by Popular Electron¬
ics, have faded even further into oblivion. It is also worth
pointing out that variations between implementations of
BASIC generally force one to re-write programs when trans¬
porting them from one machine to another. In general, in a
field developing as fast as microcomputing, standards will
merely hinder progress.
Besides these general considerations concerning the desir¬
ability of standards in the microcomputing field, there is
the question of applicability when establishing a language as
a standard. No language is good at everying; the so-called
“general purpose languages” are good at nothing and merely
mediocre at everything. BASIC has been discussed above;
FORTRAN is very similar, only, if anything, worse. Most
of the structured languages, while syntactically relatively
clean, are very rigid, limiting, and poor at dealing with amor¬
phous data or problems. PL/I, the language that was to be
all things to all people, is a syntactic disaster, a language so
huge that few people know all of its arcane abilities and dis¬
abilities, a partial combination of ideas and constructs stolen
from many other languages.
This article was originally intended to extoll the virtues of
my own favorite language, SNOBOL4. SNOBOL4, though
designed as a string-processing language, is good at a wide
variety of things, including, contrary to popular belief, nu¬
meric processing. However, I would not recommend it for all
purposes to all people; it is poor at dealing with file I/O,
for example, and has even less control structure than BASIC.
There is no easy way to correct these deficiencies, as they are
due to the basic syntactic structure of the language.
Several people have suggested designing a new language as
a standard for microcomputing. 4 This has all of the arguments
above against it as well as some others. There are already
literally thousands of languages available, and there is no
call to write a new one unless one has some radically new
idea or application. Moreover, most of the well-known lan¬
guages already have textbooks available for them, a group of
people who are familiar with the language, and often a rigid
standard. All of these things would have to be built up from
scratch if a new language were made standard. At least one
of these attempts is doomed to failure because the author is
attempting to include “all of’ PL/I, FORTRAN, BASIC,
ALGOL, SNOBOL, COBOL, and bits of RPG and APL. 5
Assuming that this is possible in under a megabyte (many big-
computer PL/Is run to hundreds of kilobytes), it would be
a syntactic catastrophe. Sure, maybe such a language could
do everything PL/I, FORTRAN, et al. can, but then so can
machine language. Using all that power would be difficult,
to say the least. The enormous power and elegance of such
languages as APL and SNOBOL4 is due to their syntax, which
could not possibly be made compatible with PL/I, for
example. (cont’d on page 21)
Page 18
Dr. Dobb's Journal of Computer Calisthenics 8< Orthodontia, Box E, Menlo Park, CA 94025
Number 30
443
SAM 76 Language Update
No.3-July 1978
BY ANCELME ROICHEL
II This new version Is upward compatible
I version 11 with previous versions and Is the result
I <0023> 11 of user requests for means to facilitate
J_LI access to major pointers. In addition
linking of user programs to the processor
Is simplified; provisions are made for up to four overlay
zones defined by the user. These enhancements were made
without, however, Increasing the size of the processor. The
new functions are defined below:
- |9cn,current,new| Change function Name
I This function has now been enhanced
I so that execution of Jews/ without
I arguments serves to reduce the work
I space to a suitable minimum.
The neutral form of this function may be |1 Tl
used to "re-speclfy" size of Inter record || *ot"
gaps and length of leader and trailer; II Output Text 11
the two forms of this function are: I I I I
Jot,nl,n2,...,nN/= which serves to "output texts" whose
names are symbolized by "nl", "n2", "nH"; the overall output
is bounded by 64 bytes of leader, aDd Individual texts are
separated by 16 bytes of gap.
&ot,leader,gap,nl,n2,...,nX/= first resets the
specifications for leader and gaps to the new desired
decimal values symbolized by "leader" and "gap", and then
outputs the texts In the normal manner.
I
I
I
it r
"cws"
11 Change Work Space!
U_L
This function allows user to rename any of the resident
function "current" names to any desired "new* name; these
new names must consist of two or three alphabetic
characters; In changing names the user should be
particularly careful In his command sequence. At this time
"os" and "Is" should not be changed.
• IqloI Query current 10 assignments
The value of thi3 function Is In the current "X" base the
value of "IQBTTE" as defined by the monitor * if such a
facility Is provided.
- |slo,lobyte| Set 10 assignment
This null valued function Is used to reassign the monitor
"IOBTTS" If provided for. It should be noted that a "cold"
start entry into the processor carries with It the current
monitor assignment; If this function Is used then a "control
C" or "ex" exit causes restoration back to the original
assignment. A "warn" reentry, or a "hot* continue causes
reassignment to the setting In force at the time of exit.
- |xll,90| Xamlne Label List
The value of this function Is a list of internal system
labels available for examination by name; these labels nay
be actual values, identify locations of program entry points
or tables, or give addresses of memory locations in which
system pointers may be found. Each label name is preceded by
the string symbolized by "s0". (Label names and their
purpose will be described later).
- |xal,label,offsetl Xamlne Address of Label
The value of this function Is the value of the "label" to
which the value of the "offset" is added. Both the value
returned and the "offset" are In the current "X" base.
- Inud,function,arguments! lull Display mode
The "nul" function serves to modify the scanner to the end
that instead of a value being returned by the function whose
name Is symbolized by "function" (with Its appropriate
arguments), output of what would have been the value is sent
to the currently assigned "console" device.
The exit function In version <0023* has 11
been enhanced to automatically reduce the 11 "ex" 11
work space to a suitable minimum prior to IlExit functlonll
returning to the operating system. (J_ Ll
Reentry automatically restores the work
space to its maximum allowable size. Hext enhancement will
be to Implement the passing of a file name and other
Information back to the operating system.
The accompanying figure shows a typical arrangement of the
user work space, as well as associated pointers and their
names. This work space nay be located either below or above
the main system program, can be saved after having performed
the "ex" exit function, and this saved file can be reloaded
In another system with its workspace in a different area of
the machine; a "hot" reentry permits the process terminated
by the "ex" function to resume with the next and other
subsequent unevaluated expressions.
Typical system labels as determined by ||
the "xll" Xamlne Label List function are |I System Ii
given below with their characterization. jj Labels
IJ_LI
"AST” ; Address System subroutine Table
"ASV* ; Address System subroutine Vectors
"EHC" ; Entry Continue "hot start"
"EUR" ; Entry Restart Level “warm start"
"ESL" ; Entry Subroutine Links
"OPV" ; Offset Permanent - Variable tables
"PQA" ; Pointer overlay A - "extra*
"POB* ; Pointer overlay B - "disk"
"POC" ; Pointer overlay C - "plot"
"POD" ; Pointer overlay D - "user"
"PSE" ; Pointer service entry
"PSK" ; Pointer function *SW"
"PST" ; Pointer function "ST"
"PUL" ; Pointer user link table
"PWA" ; Pointer Work Area start
"TAE" ; Text area end
"TAH" ; Text area high
"TAL" ; Text area low
"TAX" ; Text area max
Details of the mechanism of linking the overlay areas to the
system function table, and details of user application of
system subroutines will be described In a later write up.
Tl The Inquisitive person may begin to
Exercise for 11 Investigate the system subroutine
the adventurous j| system by finding the code for the
_Li "ir", "xrp", "xw", and "xwp"
functions. The entry point for
functions can be found using the "xqf" function. The
function ends with either a "Jump" or "return" instruction.
In the body of the code are some subroutine calls; the
addresses called are also found In two other places:
somewhere beyond the start of the table located at "AST"
(said table locates some fifty of the system subroutines)
and also somewhere - the same Index distance (but modulo
three) In the table created at address starting at "ASV".
The first table Is used if an instruction in one of the two
following forms is encountered in a user program:
Number 30
444
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 19
RST 6 CALL ESI
index number index number
Alternatively a "call* to the proper location in the table
of Jump rectors which starts at "AS?" will achieve the same
task.
In like manner other subroutines may be identified through
exploration of other functions.
The user may make use of the "sw" and |II
"sy" functions by storing at locations j "sw" and "sy" |
determined by %xal,PSW,offset/ and | linking |
3txal, PST, offset/, respectively, the |J_ I
memory addresses which execution of these
functions should reach. If the offset Is 0, then the
temporary table address Is given. If the offset is that
value returned by executing %xal,0PV/, then the permanent
table address Is given. The "xrp" and "xwp" functions may be
properly used to read and write In these locations.
The value of this function is the contents, in the current
"X" base, of the identified sector. Each "byte" is preceded
with the string symbolized by s0.
- Ixws,unit,track,sector,X| X Write Sector
This null valued function places the string symbolized by X
In the designated sector. If that string is greater than one
sector then only as much as will fit will be transferred.
Tl The "bf" bring file, and "uf" update
special I| file functions operate as expected
II feature of II when used with the active function
11 bf and uf II marker - namely: %bf.filename/, and
IJ_LI fcif,filename/. If the neutral form is
used then any file may be brought In
regardless of its type (provided there is room) and may be
put back on disk. Care must be used in doing this since
strange flies will not have the necessary pointers to be
compatible with the SAM76 processor. This Is a very
effective means for moving flies from disk to disk -
particularly on one disk drive systems.
For example:
fcbf.xdlr.com/:
How change diskettes
fcuf,xdir.com/:
(nav-uf-aef}
Ho-hum an already existing file message - well no natter
%ef,xdlr.com/fcuf.xdlr.com/:
Whenever a non fatal anomaly occurs ||II
during the execution of file ij Anomaly
functions, a value is returned by |j Indications |i
these normally null valued functions, i I I i
These values are in the form:
{nav-function-anomaly}
In the above indication, the function being executed is
symbolized by "function", and the anomaly type may be one or
more of the following:
"dsk" disk
"nrm" no room
"err" error
"fnf* file not found
"dir" directory
"clo" close
"ext" extension
"aef* already existing file
"rud" reading unwritten data
This overlay is nominally IE and provides at this time the
following functions:
prim
Id Ho
Description
BF
220;
Bring File
EF
224;
Erase File
FB
226;
File Branch
LF
216;
List Files
QFA
QFA;
Query File Attributes
QFE
QFE;
Query File Extension
BF
243;
Read File
SDU
SDU;
Select Directory Unit
SFE
SFE;
Select File Extension
UF
218;
Update File
WF
244;
Write File
XRS
XBS;
X Read Sector
xws
XWS;
X Write Sector
Those functions which in the preceding table have a numeric
"Id Ho" have been described previously in Doctor Dobbs as
well as in the SAM76 language manual; the other functions
are still in the experimental evaluation phase and are
described below.
- |qfa,filename,s0| Query File Attributes
The value of this function is a list of file characteristics
derived from the disk operating system directory; each
attribute is preceded by the string symbolized by "s0". One
of the attributes is the file size expressed as a decimal
number of 256 byte pages.
- |qfe| Query File Extension
The value of this function is the current setting of the
file extension; note that there is a difference between
■blanks" or "spaces" and "null" or zero.
- |sdu,d| Select Directory Unit
This null valued function allows the user to designate the
Directory unit to be accessed by the various file functions;
a Directory unit is any device which has a directory
structure and could be cassette as well as disk.
- |sfe,extension I Select File Extension
This null valued function is used to preset a desired file
extension so that the extension need not be used in any of
the file functions. In effect this may be used as a
classification means. The extension nay be set to any
desired three (or less) symbols, including spaces and ???,
or to the null string (viz: %sfe/) with varying effects.
- |xrs,unit,track,sector,s0| X Head Sector
This new enhanced version Is available on I
paper tape or TDL cassette as follows for lAvailablllty II
a postpaid price of $8.00 - ($2.00 credit J _LI
will be given to original purchaser of
earlier version returned with order); POLT-88 version for
8080 only on cassette $8.00; CPM version on standard
diskette $15.00.
Addresses In table below are all In HEX.
Type
AST
TAR
TAM
START
EHD
Z80 High
0100
0400
7FFF
8000
SFFF
8060 High
0100
0400
7FFF
8000
ASF
Z80 Low
0100
3400
FFFF
1000
2FFF
8080 Low
0100
3400
FFFF
1000
3SF
8060 Poly-88
4800
5000
FFFF
2000
4SF
Page 20
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
445
Motes: TAR : START - OPT; all Tersion with AST at 0100 are
CPM compatible; Z80 Terslont make use of RST0 thru RST6
while processor Is running and restores RST0 on exit;
TAM=FITF Is theoretical aaxlaua reduced by else of operating
systea used; CPM diskette contains low terslons; the disk
oserlay Is at C00, and other overlays are at 400 and 800; It
Is possible In the CPM systea to run prograas which are
saaller than 21 without affecting the SAM76 processor.
Text book describing the language in siaple terns is
available for a price of $12 - postpaid. (Specify bound or
loose leaf). Systea loader booklet appropriate to object
code foraat Is $2.
I The source prograa for the disk
I functions as lnplenented In the CP^f
I version will be published In Dr. Dobbs
I Journal, ' however copies nay be
purchased for the iapleaentatlon of
the nonent - no guarantee that It will Batch the object code
furnished - but to serve as a model for Iapleaentatlon in
other disk systeas; price is $10.00 postpaid; available as
xerox printed copy or In aachlne readable fora on standard
diskette or paper tape ITDL macro foraat].
SAM76 Inc., Box 257, R.R.l, Pennington, H.J., 06534
iiSource for CP/to j
11 Disk functions |
(cont’d from page 18)
Recently, PASCAL has been hailed as the “next” standard
language. 6 Besides the arguments above against standardiza¬
tion, I am not very impressed with PASCAL as a language.
Some syntactic kluges have been pointed out already, 7 but the
main problem with PASCAL is that it is one of the class
known as “structured” languages; a misnomer, as SNOBOL4,
for example, has a much neater, more elegant, and simpler
syntax. That PASCAL is structured means essentially that
the programmer is limited with respect to the control structure
that he can use. This makes the source code easier to under¬
stand and debug, but it restricts the programmer and may
discourage creativity. The controversy over structured versus
nonstructured languages that raged in Communications of
the ACM and similar publications for several years seems now
to be over, structured programming techniques having emerged
victorious; but this does not mean that you, or I, or anyone
else has to agree.
Rather than making PASCAL or some other single lan¬
guage a standard, what is needed is a total lack of standards,
allowing the programmer to choose which language to use
for a given application based on the problem’s nature and his
personal preference. Each microcomputer manufacturer
could write one or several languages that had not yet been
implemented for their processor. Transportability between
machines could be provided by device-independent I/O:
the user, or, better, the maker of the user’s mainframe, would
write a set of I/O subroutines for the user’s hardware configu¬
ration and I/O devices that would be called by the language
interpreters and compilers, these being written with calls to
user-provided routines only. Repeatability of code would
be very helpful. Alternatively, the writer of the language might
spend the small amount of extra work needed to modify the
basic program for use with a variety of common systems.
Some software is already being offered this way.
Some obvious first choices for languages to implement
on microcomputers are PASCAL, ALGOL, LISP or one of
its many variants, SNOBOL4, RPG II, GRASS, SKETCHPAD,
APL, MUMPS, C (anyone for MULTICS on a micro?), GPSS,
SIMSCRIPT, and a TRAC*-like language.
A lack of a high-level programming language standard
would not only give the user the benefit of a wide variety of
languages to choose among, it would also be to the advantage
of the computer makers: there is certainly more money in
being the first to introduce a SNOBOL4 than in being the
hundred and first to produce a BASIC.
References
1. See, for example, Marc LeBrun, "Tilting at Windmills, Or, What's
Wrong with BASIC," People's Computer Company vol. 2 no. 1
(December 1972) p. 5.
2. John McCallum, "The Altair (S-100) Bus Forum: PCC 77," BYTE
vol. 3 no. 3 (March 1978) pp. 148-151.
3. Robert Suding, "Why Wait? Build a FAST Cassette Interface,"
BYTE vol. 1 no. 11 (July 1976) p. 46.
4. Glen A. Taylor, "Language Development: A Proposal," BYTE
vo.2 no. 11 (November 1977) pp. 190-191.
5. Peter Skye, "The 8080 High Level Language Project of Peter Skye,
Continued," BYTE vol. 2 no. 5 (May 1977) pp. 68-70.
6. Carl Helmers, "Is PASCAL the Next BASIC?" BYTE vol. 2 no. 12
(December 1977) pp. 6-8 and 184-185.
7. Leigh Janes, "Reactions to Previous Comments," BYTE vol. 3
no. 2 (February 1978) p. 159.
♦Trademark of Rockford Research, Inc.
Number 30
446
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 21
The Heath H-8 System
BY TOM WILLIAMS
Editor
The Heathkit H-8 computer system has been on the market
for over a year now and since introducing the basic system,
Heath has been gradually adding accessories to its product line.
Somewhat more controversy than is usual for the introduction
of “another 8080-based system” surrounded the coming of the
H-8. Now that most of the dust has settled, however, and
Heath has followed up with the introduction of a floppy
diskette system, it seems a good time for a calmer look at the
H-8 and its present and future peripherals.
Since the microcomputer market is so vast and varied, any
evaluation must, in addition to a critique of hardware and soft¬
ware, take into account the portion of the market a manufac¬
turer appears to be aiming at and the apparent suitability of
that product. Since this is the sort of exercise that makes or
breaks executive careers, I will not suppose that my judgments
are the “last word” on the subject.
The H-8 is an unconventional looking 8080 system and
gives evidence of having been designed from the “ground up”
without prejudice by previous designs. The two most striking
features are the front panel display and keypad, the arrange¬
ment of the mother board with its Benton Harbor Bus ... and
the lack of a cooling fan.
The front panel display allows the user to examine (and
alter by means of the front panel keypad) the contents of
memory locations, and registers and to address I/O ports. The
display is in split octal which is unfortunate since the majority
of published microcomputer software is in hexadecimal. This
is not so bad as long as one is working within octal, but
refering to other material published in hex and then converting
can be annoying.
The mother board, which is mounted in the right side of
the cabinet instead of on the bottom as in many S-100 sys¬
tems, incorporates Heath’s own bus design, the Benton Harbor
Bus. The introduction of this new bus design has been one of
the more controversial aspects of the H-8. It is a 50 pin bus
with all but seven pins permanently defined. And Heath has
designated those pins it reserves the right to change in future
products. Heath claims cost and engineering considerations as
the main factors influencing the introduction of the new bus
structure as well as the fact that the S—100 bus was created
before the development of a system controller. One of the
main considerations, according to Heath, was to insure that
signals which could possibly interfere with each other were not
on adjacent bus lines. A detailed discussion of Heath’s new bus
by Tom Yeager, chief computer engineer for Heath, can be
found in the August 1977 issue of Interface Age.
Interference and impedance considerations also play a role
in the discussion of an extender board. Heath recommends
working on boards in a bus slot by moving the board in
question to the rear of the cabinet and removing enough other
boards to make room. This is not the most convenient
arrangement and definitely awkward in the case of the CPU
board which is connected to the front panel display board by a
short three-wire harness. You certainly can’t get a logic probe
down between them and this leaves the scary alternative of
probing about on the foil side keeping track of all the pins in
reverse order. Nonetheless, Heath has discouraged use of an
extender card for servicing because of the possibility of its
changing the transmission characteristics of the bus. The one
attempt by an independent manufacturer to make an extender
card was an awkward affair and the instructions told the user
to steady the board with one hand while working on it.
H8 System with H9 Video Terminal
All this aside, if we grant the fact that the Benton Harbor
Bus is on balance an engineering and cost advance over the
S-100 design (or lack of it), we must still recognize that there
are powerful factors which would tend to deter a manufac¬
turer from introducing an improved design. The most obvious
of these is that there are no accessories being manufactured for
that bus at the time it is first put on the market. No company
can come out with everything at once. I have heard from
Heath that they are planning many more goodies, but the fact
is that at the moment you just can’t get a modem or video
graphics board for the H-8. In fact, the only serious indepen¬
dently produced product for the Heath bus to date is the God-
bout 12K RAM board. The lack of such accessories can act as
a deterrent to the potential customer, and the fact that Heath
nonetheless decided to market a new bus design speaks for
their confidence in their product.
One of the most striking features of the mainframe, and
one which attracted the immediate attention of the computer
Page 22
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
447
music people here at People’s Computer Company, is the ab¬
sence of a cooling fan. Considerable design effort seems to
have gone into producing a machine which could run without
an AC motor in the immediate vicinity. The cabinet is vented
on top and bottom and the voltage regulator ICs on the
various boards are mounted on aluminum heat sink brackets
at the end of each board. These brackets would be inadequate
heat sinks in themselves, but they bolt to the bottom of the
chassis and to a tie bracket at the top which in turn is attached
to the metal cabinet. They thus provide for cooling by means
of a combination of convection and conduction to the mass of
the unit. This bracket on the unit operating with three 8K
RAM boards, disk controller and serial I/O board was rather
warm to the touch but still seemed equal to the task.
The mother board which is mounted in the right side of the
cabinet, comes with connectors for seven boards in addition to
the CPU and front panel with the rearmost connector reserved
for external expansion. The power supply consists of a +8
Volt, 10 Amp supply (regulated to +5VDC on each board) and
a ±12 volt supply at 500 mA to provide the +12 and -5 Volts
required for the CPU — enough for ten boards averaging 750
to 800 mA each.
OOOOOOA
to
003377A
004000A
to
023377A
024000A
to
027377A
030000A
to
037000A
040000A
to
041147A
041150A
to
042177A
042200A
to
SYSFWA-1
SYSFWA
to
LAST RAM
ADDRESS
PAM-8 ROM
(1 K)
UNUSED
(4 K)
HDOS RAM WORK AREA
(1 K)
HDOS ROM
(2 K)
SYSTEM RAM AREA
(359 bytes)
USER STACK AREA
(279 bytes)
USER PROGRAM AREA
RESIDENT HDOS SYSTEM
(approximately 2 K)
Memory Map Courtesy Heath Co.
Heath kit H8 Digital Computer Mainframe
Ideas for expansion have been incorporated into the
original design. In addition to the rearmost mother board con¬
nector, memory addresses have been reserved for various
expansion devices. The front panel ROM monitor occupies the
first IK of memory space. An additional 7K are reserved. The
disk controller ROM and RAM, for instance, are mapped into
this reserved area with plenty of room left over for other
things. The fact that the monitor and this much reserved
memory space are located at the bottom of memory means
that a great deal of 8080 software, which requires RAM
starting at the very bottom of memory cannot be used with
the H-8 system. There are, of course, ways to get around this
and it is possible to disable the front panel ROM.
Heath is currently marketing two memory boards — a 4K
(expandable to 8K) and a 16K board — and two I/O boards.
The I/O options currently consist of the serial/cassette I/O
board with one serial port and cassette interface, and the
three port parallel board. Heath has just begun selling a four
port serial card now available in assembled form for $250.
These I/O cards all have one interesting component in com¬
mon: the 8251 USART.
All Heath software uses the same console driver and in the
serial board, the 8251 is used to take the parallel data from the
data buffer (or put it on as the case may be) and convert it to
serial data. On the parallel card, the serial output of the
USART is run into a UART and converted back into parallel
data. This technique allows the use of the same console driver
since in either case the CPU is “looking” at the 8251.
The Terminal
The H-9 terminal, while a good value for the price of $550,
is the weakest part of the system. It provides a 12 inch CRT
displaying 12 lines of 80 characters — upper case only. The dis¬
play is crisp and solid, but users may find the 12 line limit
somewhat inconvenient. A very useful feature, however, is the
short form display mode. This switch-selectable option
displays information as four 20 character columns, each 12
Number 30
448
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
Page 23
lines long, and is excellent for displaying long lists of numer¬
ical or similar data. In the short form mode, the display scrolls
off to the left when the screen is full.
A third display mode, the plot mode, will display a dash at
a proportional distance above the plot information code (an
ASCII character) which is repeated four times on four
lines (?). This is a rather bizarre way of presenting the infor¬
mation and I have yet to find a practical use for the plot
feature. It may have its advantages, but it remains aesthetically
displeasing.
The H-9 has a serial port (RS232), which is usually con¬
nected to the H-8, and also a parallel port. The parallel port
might be a way of circumventing the need for a parallel
I/O card in some cases or as a printer port. I have used it as a
means of inputting lower case characters from a separate key¬
board after converting the H-9 to display lower case (DDJ
Vol. 3 No. 28, p. 30).
The keyboard of the H-9 is adequate but a trifle inconveni¬
ent. The keys are all the same size and color and the RETURN
key is located right next to the SCROLL and LINE FEED
keys. This has caused some aggravation with illegal character
error messages and the like.
Software
Heath supplies a full set of software on cassette with the
H-8 mainframe. This includes a console debugger (BUG-8), a
text editor (TED-8), an assembler (HASL-8), and Benton
Harbor BASIC. There is also a cassette-based extended version
of BASIC available for $20 which includes string functions and
file capabilities.
Benton Harbor BASIC is a good value for the price, but it
does not have some of the added features of some other
versions on the market. The extended version occupies about
9.2K and incorporates some rather novel features while omit¬
ting some of the editing and renumbering capabilities found in
other BASICs.
BH BASIC represents numbers internally in 6 digit floating
point. I did notice that raising a number to a power (even an
integer) does not give a precise result because BASIC executes
this command by multiplying the natural logarithm and then
raising e to that power. Thus: (XtY) = EXP(Y*LOG(X)).
Some of the unique features include using a Control B to exe¬
cute a designated GOSUB from the keyboard while a program
is running. Other control functions give access to the front
panel display (for monitoring a register or memory location)
and control of the real time clock.
Some of the extended BASIC formats are:
Internal line format:
2 bytes: line numbers
1 byte: carriage return (new line)
1 byte each for command and following space
1 byte each for character in the line which is not covered
by the above, except that spaces, line number and start
of text are ignored.
Number = 6 bytes
Array = 6 bytes + 2*(no. of dimensions) +
4*(no. of elements)
String = 6 bytes + (2 bytes + no. of characters)
String Array = 6 bytes + 2*(no. of dimensions) +
4*(no. of elements) + [2*(no. of ele¬
ments) + no. of characters].
New Products
Heath people are reluctant to discuss new products until
they are almost realities. Their reasoning is entirely commend¬
able, given the sorry history of the industry on this point
in the past, but it does run athwart my function as a jour¬
nalist. Therefore, I shall report those things Heath has ad¬
mitted to definitely having on the way and then the wild,
unsubstantiated rumors. The real things include two soft¬
ware products: a diskette version of Microsoft BASIC and a
disk version of UCSD Pascal, both to be available in March
of 1979. Also, a dot matrix impact printer was shown at the
Philadelphia show in August and should be available in late
December or January. Projected price, $895 assembled,
$595 in kit form. There are rumors that Lifeboat Associates
of New York was interested in adapting CP/M to run on the
H-8, and Tony Gold of Lifeboat Associates told me they were
interested in just that, but had not yet gotten the necessary
technical information from Heath. The author of SAM 76
(see DDJ No. 21, Jan, 1978) reports a similar problem.
HDOS/Diskette System
The Heath H-17 diskette system is based around the
Wangco model 82 drive unit. Heath sells a cabinet which will
accomodate two drive units and there appears to be no
provision for expansion to additional drives. We have seen the
wired version and the kit is due to be available in the near
future. The kit assembly should be fairly simple, consisting of
little more than assembling the controller board, power sup¬
ply and cabinet.
The drive uses a stepper motor and worm gear to position
the head. The disk is hard sectored and organized into 40
tracks, 10 sectors each for a total of 102.4K bytes of storage.
Heath appears to be quite proud of the access time of its disk
drives, but is careful to caution the user not to confuse track
seek time with random sector access — the true time it takes
to get to the data. Both drive units I used performed reliably
at a track to track seek time of 8 msec. This means an average
track seek time of 104 msec. Add to this a rotational latency
of 100 msec, (the average time it take a sector on a given track
to come under the head) and we have a random sector access
time of 2 04 msec. The HDOS and controller make use of the
motor on feature of the model 82 drive to extend motor life.
If no commands are sent to the drive for a certain length of
time, the spindle motor shuts off. When required, the spin¬
dle motor turns on and takes one second to come up to speed
before accessing can take place.
Page 24
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
449
HDOS appears to be a rather sophisticated diskette oper¬
ating system and can best be described as consisting of 2 major
portions of interest to the user: the system diagnostic and
optimization portions and the general operation portions.
These distinctions are my own. The main diagnostic programs
in HDOS are contained in TEST 17 which starts out by check¬
ing the drive’s rotational speed and displaying it on the H-8’s
front panel LEDs. If the rotational speed does not fall within
the parameters required, the user can make a small adjustment
with a trimpot on the drive’s circuit board.
The next test is a general read/write test on each sector to
test the head and seek mechanism. This is an exhaustive test
making three complete passes and requiring fully 40 minutes
to complete. Any problems are displayed as either “hard”
or “soft” errors and the user is referred to the media check
or to the troubleshooting section of the manual. A media
check then performs a test on a diskette to determine if there
are any bad sectors. The results tell how many bad sectors
were located and lists the individual sectors. During the initial¬
ization procedure for that diskette, the user can enter the bad
sectors and HDOS will ignore them while using the remaining
good ones.
The final test checks the track to track seek time of the
individual drive units. HDOS makes its first attempt at 18
msec. It then displays the highest speed at which the unit
will seek reliably. This information can then be used during
system optimization to set the seek time for the drive.
The SYSGEN portion of HDOS allows the user to copy the
minimal operating system onto another diskette to use as a
system volume so that the original can be safely stored away.
To this minimal system can be added whichever other pro¬
grams from the distribution diskette the user wishes. Thus,
several system volumes with various portions of the distribu¬
tion software can be created, such as a diskette with BASIC,
one with the editor and assembler, and so on. The minimal
system contains among other things, SYSGEN itself, PIP, the
peripheral interchange program that allows copying a file from
one drive or peripheral device to another, and SET for opti¬
mizing the system. With this latter program the user can set
the track seek time to the optimum determined in the diag¬
nostic sequence, set the console or alternate terminal to
backspace and set the proper number of stop bits. STATUS
displays disk statistics including the number of reads and
writes and, more importantly, the number of hard and soft
errors encountered. An error that occurs 10 times in succes¬
sion is classified as a hard error.
The distribution diskette sells for $100 and contains disk
versions of all the software supplied with the H-8: BUG-8,
HASL-8, TED-8 and BASIC. In addition, there are a number
of programs specifically oriented toward the operation of
the disk system. These include:
BASCON This allows the user to read a BASIC program into a
buffer in memory and convert that program as a file onto
the diskette which will run under the HDOS BASIC.
TXTCON Like BASCON, this allows the user to convert
cassette text files created under TED-8 into text files on
the disk.
ONECOPY This is a program for copying files in a system
with only one drive unit. ONECOPY is one of the more
fun utility programs in that it reads a portion of the file
from the source disk into a buffer in RAM. The size of this
buffer is dependent on the amount of memory in the
H-8. It then displays the word “destination” on the console
as well as the characters DES on the front panel LEDs.
The user then switches diskettes, hits RETURN and that
portion of the file is written onto the new diskette. The
system then displays the word “SOURCE” on the terminal
and Sou on the front panel, instructing the user to switch
back to the source diskette for another portion of the
file to be copied. This process continues until the entire
file is copied.
Documentation and Service
If there is any one area where Heath outshines all comers,
it is in documentation and customer service. Heath’s assembly
manuals are of a uniform quality—as they are in all Heath
products-containing illustrated, detailed, step by step instruc¬
tions with interim checks and voltage/resistance tests. But the
documentation goes far beyond this.
The operation manuals contain full schematics, timing dia¬
grams, options for configuring I/O, and detailed trouble¬
shooting flowcharts. The one criticism is that the schematics
contain only Heath part numbers which must be referenced
to the manuals to find out what the actual IC number is. It
seems that this is an inconvenience it would have been so easy
to avoid. Also included in the operation manuals for the H-8
and H-9 are circuit descriptions and general theory of opera¬
tion sections with timing diagrams and drawings which allow
the interested user to study the details of his system to the
depth of his interest.
The software reference manual contains a detailed des¬
cription of all the software, with many examples of the unique
features. These are not courses in programming, nor are they
meant to be, but user reference material. Also included are
listings of several BASIC utility routines, including the console
driver, as well as listings of the front panel monitor and disk
controller ROMS.
Customer service is available through the factory or through
any one of 50 Heath Electronic Centers around the country.
Each has factory-trained people specializing in different
Heath product lines. For those who do not live near a Heath-
kit store, the company maintains a telephone number in
Benton Harbor, Michigan with technical advisers on hand to
answer desperate questions from the hinterlands. I have
checked out this number several times and can report some
very positive experiences.
In early January, while I was constructing the H-8 itself,
the line would often be busy. If it was, the woman who an¬
swered when I finally got through asked how many times I
had tried and found the line busy. By Spring they seemed to
have gotten their traffic problems ironed out and there is little
trouble getting ahold of a technician. The man at the other
end has a system in front of him and his answers to my some¬
times manufactured (and occasionally genuine) questions
were always quick and clear. What you get is either a direct
answer or a list of steps for isolating the problem such as
swapping or substituting various ICs. To customers who have
long since resigned themselves to futile letters and the general
eral runaround, this kind of treatment is nothing less than
heavenly and puts real substance behind the Heath motto,
“We won’t let you fail.”
Number 30
450
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 25
BASEX: A Fast, Compact Interactive
Compiler for Microcomputers
BY PAUL K. WARME
423 Kemmerer Road
State College, PA 16801
BASEX is a new intermediate-level language for microcom¬
puters that combines some of the best features of both BASIC
and Executable machine language code. It is almost as easy to
use as BASIC and yet, it is nearly as fast and versatile as assem¬
bler language. The BASEX compiler is interactive ; that is, it
permits you to enter, list, edit and run your program without
the help of any auxiliary programs, such as editors or linkage
editors. In this respect, BASEX is more like BASIC than FOR¬
TRAN, PASCAL and other compilers. Most BASEX com¬
mands resemble their counterparts in BASIC language, and this
facilitates learning the language and translating programs from
BASIC into BASEX.
The main advantages of BASEX are its speed (typically 7 to
20 times faster than BASIC) and the compact size of BASEX
programs (typically at least 6K bytes smaller than similar pro¬
grams written in BASIC). This difference in size is due to the
fact that the BASEX compiler does not have to be resident
during execution and the run-time subroutines occupy only
2K bytes of memory. However, since the BASEX compiler and
run-time routines together use only 8K of memory, it is gener¬
ally more convenient to leave the compiler in memory while
debugging your BASEX programs. A microcomputer with 16K
bytes of memory is adequate to make full use of the power of
BASEX. Since the BASEX compiler is able to decompile its
own object code very rapidly, you only need to save one copy
of the program (the object code). This is a distinct advantage
over FORTRAN and other compilers, which save separate
source, object and executable versions of the same program.
The Origins of BASEX
About a year ago, I was having a lot of fun with my IMSAI
8080 microcomputer until I tried some BASIC programs to
draw pictures on my video terminal and play electronic music.
Unfortunately, BASIC was too slow to permit smooth motion
of video images and accurate timing of musical notes. After
buying a chess program written in BASIC, I found that it took
about ten minutes to make a move. The Bulls and Cows game
(similar to Mastermind) in 101 Basic Games often took 10 to
30 minutes to make a move, much to my consternation. In
short, I discovered that there is a rather large class of problems
that demand greater execution speed than BASIC can deliver.
Unfortunately, many of the things that I wanted to do, such as
interactive graphics, electronic music and word processing, fall
in this category.
At the time, it seemed that programming in assembler lan¬
guage was the logical alternative to BASIC, although I dreaded
the thought of writing large programs (>8K) in assembler lan¬
guage. When I started translating one of these large programs
into assembler language, it was quite discouraging. I had to re¬
invent the wheel at every turn, writing routines to input and
output numbers and text, multiply, divide, etc. Then I noticed
that certain operations were done repeatedly in different parts
of the program and could be called as subroutines, thus avoid¬
ing repetitious coding. After thinking about this, it occurred
to me that most of these same subroutines would be needed in
just about any large assembler language program.
From this point, it was easy to conclude that assembler lan¬
guage programming would be much easier and faster if all of
these useful subroutines could be made available in any pro¬
gram. A method was needed to pass arguments to the subrou¬
tines; the most straightforward way of doing this would be to
insert the addresses of the arguments immediately after the
subroutine call. This approach requires that a region of mem¬
ory be set aside for a symbol table ; that is, a table containing
the names of variables and their present values.
Pulling on the Bootstraps
The next step was to write a set of subroutines that would
be generally useful in almost any program and then write a
compiler in BASIC that would translate three-letter mnemonic
names of each subroutine into a CALL to the corresponding
subroutine. The compiler also had to copy each new variable
name included in the user program into the symbol table and
leave a two-byte space for the value associated with that
name. Once the compiler was working in BASIC, I used it to
translate the compiler into BASEX (in other words, a series of
CALL’S to BASEX subroutines). If this sounds circular, well,
it is.
I now had a compiler written in BASEX which worked
about 20 times faster than the compiler written in BASIC. The
speed advantage of BASEX was already paying off! In order to
put some finishing touches on the BASEX compiler, the origi¬
nal version was copied to a different part of memory and the
original compiler was used to modify the relocated copy. In¬
cidentally, writing a compiler in a new language is a good test
of its versatility and power. In fact, I decided to add a few
more subroutines to the run-time package during the process
of translating the compiler into BASEX.
An Overview of BASEX Program Commands
Table I summarizes the commands available to BASEX
users. Notice that all of the command mnemonics are three let¬
ters long and the data types include 16-bit signed constants
and variables (-32,767 to 32, 767), one-dimensioned arrays of
up to 255 values, string variables of up to 255 characters and
string constants of any length. One unusual feature of BASEX
array names is that the “(” is treated as part of the name,
much like the “$” at the end of a string name. Thus, the clos¬
ing parenthesis, ), is not needed after the element. For exam¬
ple, DATA( 1 means the first element of the array called
DATA(. Variable names may contain any number of charac-
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
451
ters (or numbers), which makes BASEX programs more de¬
scriptive than BASIC programs. Since variable names are saved
only once (in the symbol table), the memory cost of using
longer, more meaningful names is slight.
Pseudo - Operations:
The BASEX pseudo-operations are used only by the com¬
piler; they are skipped over during execution of the program.
The REM command is for comments, which are set off by ex¬
clamation marks. The DIM command tells the compiler how
much space to save in the symbol table for arrays and strings.
The *** command marks an entry point in the program which
can be addressed by the GTO, JMP and CAL commands. This
feature of using names instead of numbers for entry points
adds to the readability of BASEX programs. The END com¬
mand indicates the end of a procedure or program.
Arithmetic and Logical Commands:
All of the arithmetic and logical commands place their re¬
sult in the accumulator, which is referred to by the letter A
(this is the only reserved variable name). The accumulator, A,
is a 16-bit variable that can be used just as any other BASEX
variable. The sign of the most recent arithmetic or logical op¬
eration is retained for conditional branching via the JMP com¬
mand. The arithmetic commands allow addition (ADD), sub¬
traction (SBT), multiplication (MLT) or division (DIV) of
16-bit signed constants or variables. Commands are also avail¬
able to determine the ABSolute value (ABS), INCrement a
value by one (INC) or DECrement by one (DEC). The logical
commands (AND, NOT, IOR, XOR) operate simultaneously
on all bits of a 16-bit constant or variable.
Load and Store Commands:
BASEX provides several ways to load and store values in
memory. The SET command is equivalent to the LET com¬
mand in BASIC. The DEF (DEFine) command allows multiple
SETs to be combined in one command. However, it is more
convenient to use the DAT command to assign values to suc¬
cessive elements of an array. The BRD (Byte ReaD) command
works like the 8-bit PEEK or EXAM functions in BASIC,
while the WRD command gives the BASEX user the added
capability of reading 16-bit words anywhere in memory. The
complementary functions of storing bytes or words in memory
are performed by the BRT (Byte wRiTe) and WRT commands.
These commands are analogous to the POKE or FILL com¬
mands in BASIC, but it is easier to store multiple bytes or
words using BASEX, since multiple values can be stored with
a single command.
String Commands:
Basex needs only one very powerful string command, STR,
to duplicate the ASC, CHR$, LEFTS, MIDS and RIGHTS
string functions used in some versions of BASIC. Characters
can be transferred back and forth between strings and variables
(or arrays). Substrings are specified in terms of their first and
last character positions in a given string. The CMP command
CoMPares the alphabetic order of two strings and allows con¬
ditional branching via the JMP command, based on the out¬
come of the comparison. Other useful string commands are the
LEN command to determine the LENgth of a string or sub¬
string and the VAL command, which returns the numeric val¬
ue of a string in the accumulator, A.
Program Control Commands:
One of the most useful program control commands is the
JMP command, which branches to a labelled (***) entry point
if a particular condition has resulted from the most recent
arithmetic, logical or compare command. The conditions that
can be tested for are EQual (EQ) to zero, Not Equal (NE),
Less Than (LT), Greater Than (GT), Less than or Equal (LE)
and Greater than or Equal (GE) to zero. The GTO command
can be used for unconditional branching. Structured program¬
ming buffs may choose not to use the GTO command, but
after all, if you know where you’re going, the GTO is the
quickest way to get there. However, structured programming
techniques can be used with BASEX.
Instead of the FOR. . .NEXT loop structure of BASIC,
BASEX uses the FOR and TIL commands. The FOR com¬
mand sets the initial value of the loop variable, while the TIL
command adds or subtracts any value from the loop variable
and then checks to see whether the terminating value has been
exceeded. If not, the program branches to the statement
following the corresponding FOR command. FOR.. .TIL
loops can be nested to any depth and there are no restrictions
on jumping into or out of loops.
BASEX has a much better facility for calling subroutines
than BASIC. For starters, subroutines are called by name,
rather than by statement number, so the subroutine name can
BASEX PROGRAM COMMANDS
X,-Y and Z are variables or constants; A( is an array; S$ is a string
"TEXT" is a string constant; variable names can be any length.
>> Pseudo-Operations <<
REM !BASEXi (comments) DIM A( 10 S$ 80 (Dimension arrays & strings)
*** START (Program labels) END (End of program)
>> Arithmetic Commands << (Results are in the Accumulator)
ADD X+Y (add) SBT X-Y (subtract) MLT X*Y (multiply) DIV X/Y (divide)
ABS X (absolute value) INC X (increment) DEC X (decrement)
>> Logical Commands << (Results are in the Accumulator)
AND X&Y (logical AND) NOT X (complement)
IOR X#Y (Inclusive OR) XOR X%Y (Exclusive OR)
>> Load and Store Commands <<
SET X=Y or SET A( 1=X or DEF X*Y A( 1=X ... (equate variables)
DAT A( X=Y Z ... (initialize an array)
BRD X (read byte at X) BRT X=Y Z ... (write bytes from X onward)
WRD X (read word at X) WRT X=Y Z ... (write words from X onward)
>> String Commands <<
STR X=S$ Y or STR A( X=S$ Y (string to variable transfer)
STR S$ X X*Y or STR S$ X X=A( Y (variable to string transfer)
STR S$ X Y=S$ Z or STR S$ X Y = "TEXT" (string to string transfer)
CMP S$ X Y-S$ Z or CMP S$ X Y-"TEXT" (compare strings)
LEN S$ X (length of string) VAL S$ X (numeric value of string)
>> Program Control Commands <<
JMP CC X (jump to X on condition CC = Eg, NE, LT, GT, LE, or GE)
FOR X=Y.TIL X+Y>Z (loop) GTO Y (unconditional branch)
CAL X Y Z ... (ca.ll subroutine X) GET Y (pass Y to subroutine)
PUT Z (return Z to caller) RET (return from subroutine)
>> Input/Output Commands <<
INP X A( Y S$ Z ... (input) CHR X (print character)
PRT X A( Y S$ Z "TEXT"... (print) TAB Y (tab to column Y)
XIN X (read input port) WAT x Y (wait for condition Y on port X)
XOT X (write output port) DSI/ENI (disable/enable interrupts)
>> Memory Search and Move Commands <<
BSR X Y Z (search from X to Y for byte Z)
WSR X Y Z (search from X to Y for word Z)
MOV X Y Z (move memory from X through Y to Z)
BASEX COMPILER COMMANDS
LSI' or LSM (list all or part of the program or symbol table)
DMP or NTR (dump or enter one or more memory values)
INS or DLT (insert or delete one or more program statements)
SIZ (print program size) LOC (set program pointer)
RUN (run the program) MON (exit to monitor)
reflect its purpose. The first argument after a CAL command
is the entry point name, defined elsewhere in your program by
a *** command. The optional second and subsequent argu¬
ments specify variables to be passed to or returned from the
Number 30
452
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 27
subroutine. Within the subroutine, you can use the GET com¬
mand to receive a value from the calling program or use the
PUT command to return a value. Since the variables named in
the GET and PUT commands may be different from the names
used in the CAL command, you can reserve “local” variable
names for use in subroutines. However, any subroutines that
are compiled at the same time and share the same symbol table
may access any variable without using the GET and PUT com¬
mands. This allows “global” variables to be shared by subrou¬
tines. The RET command is used to RETum from a subrou¬
tine.
Input/Ouput Commands:
The I/O commands in BASEX make it easy to communi¬
cate with terminals and instruments of all types. To customize
BASEX for your terminal, you simply fill in the address of
your routines to input and output one character, as described
in the manual. The INP command INPuts one line of charac¬
ters or numbers, ending with a carriage return, and stores them
in the variables listed after the INP. The PRT command
PRinTs a list of variables or constants, separated by spaces.
The PRN command does the same, but omits the space be¬
tween items. You may space over to a particular column by
using the TAB command or print a single CHaRacter with the
CHR command.
If you wish to communicate directly with I/O ports, you
can INput from port X with the XIN command or OuTput
to port X with the XOT command. In both cases, the byte to
be communicated is placed in the accumulator, A. The WAT
command WAiTs until the input port specified by its first ar¬
gument gives a non-zero value when ANDed with its second
argument. You can also ENable or DiSable Interrupts with the
ENI and DSI commands.
Memory Search and Move Commands:
Since the block memory search and move commands are
extremely fast, they are indispensible for writing compilers,
editors and other programs where speed is important. The
BSR command SeaRches for a particular Byte (8 bits) within
a specified region of memory, while the WSR command
SeaRches for Words (16 bits). If the specified byte or word is
found, its address is placed in the accumulator, A, and the con¬
dition flags are set to the Less Than (LT) condition so that
a JMP command can test whether the search was successful. If
the requested byte or word is not found, the Greater Than
(GT) condition is flagged. The MOV command MOVes a group
of bytes from one region of memory to another. It gives cor¬
rect results even when the new region of memory overlaps the
old region.
Using the BASEX Compiler
The interactive BASEX compiler makes it easy to write and
debug programs. Each time BASEX is restarted, it prints
“RANGE?” and expects you to enter four numbers to desig¬
nate the first and last addresses of your program and the first
and last addresses of its symbol table. Let’s call these addresses
PRG1, PRG2, SYM1 and SYM2, respectively. BASEX works
with decimal numbers, since most people think most readily
in base 10. If your BASEX program is already loaded in mem¬
ory and you have previously declared its memory space, you
can type a 0 after the “RANGE?” prompt, and then a carriage
return (here denoted <CR>). In this case, BASEX will print
the current values of PRG1, PRG2, SYM1 and SYM2, just as a
reminder.
If you want to write a new BASEX program, you should re¬
spond to the “RANGE?” prompt by typing the starting ad¬
dress of the program (PRG1), a space, and then type the same
value for PRG2, followed by a space. The space is the pre¬
ferred separator between numeric arguments, although any
non-numeric character will do. Now, you should type the ad¬
dress of the last byte in memory that you want to set aside for
the new program, a space, and then type the same number
once more, followed by <CR>. This sets SYM1 and SYM2 to
the top of memory because the symbol table builds downward
from the top of memory. The BASEX compiler will now erase
any program that previously existed between PRG2 and
SYM1.
Whether you are starting a new program or revising an old
one, the value of PRG2 is next printed, followed by a question
mark. The “?” always signals that a BASEX program (the
compiler, in this case) is waiting for user input. You can now
type any three-letter BASEX command mnemonic, a list of
arguments and then <CR>. The BASEX compiler checks to
see whether your command line begins with a compiler com¬
mand (discussed below) and if so, performs the requested ac¬
tion and then retypes the value of PRG2 and “?” once more.
If your command line contains a program command, the
appropriate CALL to a BASEX run-time subroutine is inserted
in your program, followed by the symbol table addresses of
any arguments specified in the command line. If any new vari¬
able names occur in the argument list, they are copied into the
symbol table. Next, the compiler updates PRG2 to the address
of the next available program location, prints it and waits for
another command line after the “?” prompt. Notice how the
automatic line number feature of BASEX facilitiates program
entry.
BASEX Compiler Commands
The BASEX compiler commands allow the user to list and
modify programs. The SIZ command prints the values of
PRG1, PRG2, SYM1 and SYM2 in the following format:
PROGRAM ##### ##### SYMBOLS #####
#####
The LOC command allows you to set PRG2 to any position in
your program, so that the next program command will be
inserted there. If you want to LiST your entire program, you
can type LST; if you type one number after LST, the single
command at that location will be listed or, if you type two
numbers after the LST command, all program commands be¬
tween those limits will be listed. The LSM command is used to
LiSt the entire SyMbol table and one or two arguments may
follow the LSM to list selected parts of the symbol table. As
each variable name is listed, its location in the symbol table
and the current value of that variable are also printed. One use¬
ful debugging technique is to insert an END command at some
point in your program and then, when your program halts, list
all or part of the symbol table to determine the current values
of your variables. You can now alter the values of certain vari¬
ables, list the program or modify the program. In most cases,
you can still resume your program after the END command
without harmful side-effects.
The INS and DLT compiler commands are used to INSert
or DeLeTe program lines. Both require two arguments, which
specify the first and last memory locations to be inserted or
Page 28
Dr. Dobb's Journal of Computer Calisthenics 8i Orthodontia, Box E, Menlo Park, CA 94025
Number 30
453
deleted. These locations can be determined from the program
listing. The INS command moves the last part of the program
to a higher place in memory, prints the range of the relocated
program segment, sets PRG2 to the first location to be insert¬
ed, prints PRG2 and then waits after the “?” prompt for one
or more new program commands to be entered. When you fin¬
ish entering new commands, you should use the DLT com¬
mand to delete the unused locations up to the reloaded pro¬
gram segment. In cases where the altered program will be the
same size or shorter than the original one, you can use the
LOC command (instead of the INS command) to set PRG2 to
any location in your program, enter the changes, and then
delete any unwanted commands with the DLT command.
The DMP command is available (or printing the decimal
values stored between any two memory addresses that you
specify. A carriage return and line feed are printed automat¬
ically whenever the address is evenly divisible by ten; The NTR
command can be used to eNTeR one or more decimal values
into sequential memory bytes, starting at the memory address
specified by its first argument. When you want to RUN your
program, you merely type the RUN command, followed by
the desired starting address. Since your program has already
been compiled as you entered it, there is no delay before your
program begins. The address given after RUN can point to the
first byte of any command in your program or any other pro¬
gram. You can restart BASEX at any time by typing RUN 0
or just RUN. After your BASEX program finishes, it will jump
to location 0 and restart BASEX.
The MON command allows you to exit conveniently to
your system monitor. In view of the great diversity of mass
storage devices now available, BASEX contains no mass stor¬
age handlers. However, you can use your system monitor to
save and load BASEX programs or you can even use BASEX to
write a tape handler, as will be shown by one of the examples
coming up.
BASEX Error Messages
In order to maintain fast program execution and small pro¬
gram size, BASEX is somewhat weak on error checking. Never¬
theless, it is a rare thing for a BASEX program to run wild, be¬
cause after each BASEX command is completed, a check is
made to be sure that the next byte in the program is a CALL
instruction. Any other instruction will cause the program to
halt, and error dump will be printer! and then the BASEX
compiler will be restarted. Other run-time errors (of 18 differ¬
ent types) will also halt and print and error dump, consisting
of the values of all the registers, the program location where
the error was detected, the error type number and the top
three words on the stack. In addition, when the BASEX com¬
piler detects any of nine different types of program errors, it
prints a two letter error code and ignores that command line.
Relocating LOADER for BASEX Programs
It is frequently desireable to be able to move a BASEX pro¬
gram to a position different from that at which it was com¬
piled. A special program called the LOADER (written in
BASEX) is provided for this purpose. Although the standard
version of the LOADER overlays the BASEX compiler, it can
be used to relocate the compiler or the LOADER itself. The
LOADER commands include MOV, to MOVe a program or its
symbol table to a new location, PRG to modify the PRoGram
and SYM to modify the SYMbol table to take into account its
new location in memory. The DMP, NTR, RUN and MON
commands described above are also available in the LOADER.
The FIX command is the most powerful LOADER com¬
mand; it moves the program to a new location, removes all
pseudo-operations (REM, DIM, and *** labels) and moves the
symbol table to directly follow the program. As each variable
name is moved, its new location is printed and the name is ab¬
breviated to its last letter to conserve space. Comments are
also omitted to make the program smaller. After the FIX op¬
eration, the program can no longer be listed or changed by the
BASEX compiler, nor can it be relocated by the LOADER.
This provides a measure of protection for proprietary soft¬
ware.
EXAMPLE: Memory Test Program
Let’s write a simple BASEX program to write every possible
8-bit byte in every memory location within a selected region
of memory and then read it back to verify its correctness. Of
course, any errors should be reported by giving the erroneous
value, its location and the correct value. In order to compare
BASEX with BASIC, we’ll do it first in Altair BASIC, version
3.2.
10 REM MEMORY TEST IN BASIC
100 INPOT "FIRST AND LAST BYTESFIRST,LAST
110 FOR 1=0 TO 255
120 FOR J=FIRST TO LAST
130 POKE J,I
140 IF PEEK(J)=1 GOTO 160
150 PRINT "BYTE",J,"WAS",PEEK(J),
";SHOULD BE",I
160 NEXT J
170 NEXT I
180 PRINT "DONE"
OK
RUN
FIRST AND LAST BYTES? 16501,16600
DONE
OK
In BASIC, this program took 250 seconds to test 100
memory bytes (25,600 write, read and compare operations).
Now, let’s translate this program into BASEX and observe how
similar the two programs are.
*GO BASEX
RANGE ? 11000 11000 11500 11500
11000 ? REM 1MEMORY TEST IN BASEX!
11006 ? PRT "FIRST AND LAST BYTES"
11012 ? INP FIRST LAST
11020 ? FOR 1=0
11028 ? FOR J=FIRST
11036 ? BRT J=I
11044 ? BRD J
11050 ? SBT A-I
11058 ? JMP EQ OK
11066 ? BRD J
11072 ? PRT "BYTE" J "WAS" A ";SHOULD BE" I
11088 ? CHR 13
11094 ? *** OK
11100 ? TIL J+1>LAST
11112 ? TIL 1+1>255
11124 ? PRT "DONE"
11130 ? CHR 13
Number 30
454
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 29
11136 ? SIZ
PROGRAM 11000 11136 SYMBOLS 11387 11500
11136
? LSM
11387
DONE" 11387
11395
;SHOULD BE" 11395
11409
WAS" 11409
11416
BYTE" 11416
11424
OK 11100
11429
J 0
11433
I 0
11437
LAST 0
11444
FIRST 0
11452
FIRST AND LAST
BYTES"
11452
11476
MEMORY TEST IN
BASEX!
11476
11136
? RUN 11000
FIRST
AND LAST BYTES
? 16501 16600
DONE
RANGE
? 0
PROGRAM 11000 11136 SYMBOLS 11387 11500
The execution time in BASEX is 29 seconds for 100 bytes.
This is 8.6 times faster than BASIC, even though this version
of BASIC is the fastest one tested by Tom Rugg and Phil
Feldman in their article, “Basic Timing Comparisons ... Infor¬
mation for Speed Freaks,” published in Kilobaud (June, 1977,
p. 66). When I coded their longest program, Benchmark Pro¬
gram 7, in BASEX, it ran in 7.1 seconds, whereas Altair
BASIC took 51.8 seconds and other versions of BASIC took
up to 235.6 seconds. Apple’s 6K integer BASIC took 28.0
seconds; this may be a better comparison with BASEX, since
neither of these use floating point arithmetic. However, like all
benchmark programs, there is a certain amount of variation in
performance, depending on the nature of the program. In all
of the cases that I have tested, BASEX runs 7 to 20 times
faster than Altair BASIC, Version 3.2.
EXAMPLE: Intel Format Tape Routines with Check¬
sum
The following program reads, writes and verifies tape files
in Intel format. It is fast enough to work with my National
Multiplex CC-7 data recorder running at 2400 baud (try that
with BASIC!). It will also work with paper tape or other fla¬
vors of cassette tape. The use of descriptive names for entry
points and subroutines makes the program fairly easy to un¬
derstand.
In Intel format, the first byte of a record is a colon and all
subsequent bytes are in ASCII hexadecimal form. Bytes 2 and
3 are the record length, bytes 4 through 7 are the load address
and bytes 8 and 9 are the record type (0 here). Next comes the
data, two ASCII digits per byte, and then the checksum, which
is the negated 8-bit sum of all the digits since the colon. At
the end of each record, there is a carriage return and line feed.
The verify operation is the same as the read operation, ex¬
cept that the values read from the tape are just compared to
the contents of memory. Subroutine INCHAR reads one
ASCII digit and OUTCHAR writes one digit on the tape. Both
of these routines must be customized for the user’s I/O ports.
Subroutines READCHK and WRTCHK read and write mem¬
ory bytes as two hex digits and update the checksum, while
READHEX and WRTHEX do the same thing without contrib¬
uting to the checksum. Subroutine HEX converts ASCII hex¬
adecimal digits to binary, whereas HEXOUT does the reverse
conversion and goes on to output the result.
The program and symbol table occupy 1,712 bytes and
they can be compressed to only 1,097 bytes by means of the
FIX command in the LOADER program.
PROGRAM 12288 13406 SYMBOLS 13453 14000
13406 ? LST
12288 REM 1INTEL FORMAT TAPE ROUTINES!
12294 DIM ANSWER? 6
12302 DEF TAPE 2 STATUS 3
12314 *** BEGIN
12320 CHR 13
12326 PRT "READ/WRITE/VERIFY/STOP"
12332 INP ANSWER? 1
12340 CMP ANSWER? 1 1 "R"
12352 JMP EQ READ
12360 CMP ANSWER? 1 1 "W"
12372 JMP EQ WRITE
12380 CMP ANSWER? 1 1 " V"
12392 JMP EQ VERIFY
12400 GTO 0
12406 *** VERIFY
12412 SET VRFLAG=1
12420 GTO READ1
12426 *** READ
12432 SET VRFLAG=0
12440 REM !READ NEXT BLOCK!
12446 *** READl
12452 SET CHKSUM=0
12460 CAL INCHAR
12466 SBT A-58
12474 JMP NE READl
12482 CAL READCHK
12488 SBT C-0
12496 JMP EQ BEGIN
12504 SET NBYTES=C
12512 CAL READCHK
12518 MLT C*256
12526 SET ADDRESS=A
12534 CAL READCHK
12540 ADD C+ADDRESS
12548 SET ADDRESS=A
12556 CAL READCHK
12562 FOR BYTE=1
12570 CAL READCHK
12576 SBT VRFLAG-0
12584 JMP EQ READ2
12592 BRD ADDRESS
12598 SBT C-A
12606 JMP EQ READ3
12614 PRT "V" "ERROR AT" ADDRESS
12624 GTO BEGIN
12630 *** READ2
12636 BRT ADDRESS=C
12644 *** READ3
12650 INC ADDRESS
12656 TIL BYTE+1 NBYTES
12668 CAL READHEX
12674 ADD A+CHKSUM
12682 AND A&255
12690 JMP EQ READl
12698 PRT "R" "ERROR AT" ADDRESS
12708 GTO BEGIN
12714 REM !READ WITH CHECKSUM!
12720 *** READCHK
12726 CAL READHEX
12732 SET C=A
12740 ADD C+CHKSUM
12748 SET CHKSUM=A
Page 30
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
455
12756 RET
12760 REM !R£AD 2 HEX DIGITS!
12766 *** READHEX
12772 CAL INCHAR
12778 CAL HEX
12784 MLT A*16
12792 SET C=A
12800 CAL INCHAR
12806 CAL HEX
12812 ADD A+C
12820 RET
12824 REM ICONVERT ASCII TO HEX!
12830 *** HEX
12836 SQT A-58
12844 JMP LT HEX1
12852 SBT A-7
12860 *** HEXl
12866 ADD A+10
12874 RET
12878 *** INCHAR
12884 WAT STATUS 2
12892 XIN TAPE
12898 AND A&127
12906 RET
12910 REM !WRITE TAPE!
12916 *** WRITE
12922 PRT "WRITE RANGE"
12928 INP FIRST LAST
12936 SET A=0
12944 FOR BYTE=1
12952 CAL OUTCHAR
12958 TIL BYTE+1 10
12970 REM !WRITE NEXT BLOCK!
12976 *** WRITEl
12982 SET NBYTES=16
12990 SBT LAST-FIRST
12998 JMP GE WRITE2
13006 REM !TERMINATOR!
13012 SET A=58
13020 CAL OUTCHAR
13026 SET A=4 8
13034 CAL OUTCHAR
13040 CAL OUTCHAR
13046 GTO BEGIN
13052 *** WRITE2
13058 SBT A-l5
13066 JMP GE WRITE3
13074 ADD A+l6
13082 SET NBYTES=A
13090 *** WRITE3
13096 SET CHKSUM=0
13104 SET A=13
13112 CAL OUTCHAR
13118 SET A=10
13126 CAL OUTCHAR
13132 SET A=58
13140 CAL OUTCHAR
13146 CAL WRTCHK MBYTES
13154 DIV FIRST/256
13162 CAL WRTCHK A
13170 CAL WRTCHK FIRST
13178 CAL WRTCHK 0
J. JIB b FUR BY'i'E = i
13194 3RD FIRST
13200 CAL WRTCHK A
13208 INC FIRST
13214 TIL BYTE+1 NBYTES
13226 SBT 0-CHKSUM
13234 AND A&255
Number 30 Dr. Dobb's Journal of Computer Calisthenics
456
13242 SET C=A
13250 CAL WRTHEX
13256 GTO WRITEl
13262 REM 1WRITE WITH CHECKSUM!
13268 *** WRTCHK
13274 GET C
13280 ADD C+CHKSUM
13288 SET CHKSUM=A
13296 REM !WRITE 2 HEX DIGITS!
13302 *;** WRTHEX
13308 DIV C/16
13316 CAL HEXOUT
13322 SET A=C
13330 *** HEXOUT
13336 AND A&15
13344 SBT A-l0
13352 JMP LT ASCII
13360 ADD A+7
13368 *** ASCII
13374 ADD A+58
13382 *** OUTCHAR
13388 WAT STATUS 1
13396 XOT TAPE
13402 RET
13406 END 13406 ? LSM
13453 ASCII 13374
13461 HEXOUT 13336
13470 WRITE 2 HEX DIGITS! 13470
13492 WRITE WITH CHECKSUM! 13492
13515 WRTHEX 13308
13524 WRTCHK 13274
13533 WRITE3 13096
13542 TERMINATOR! 13542
13556 WRITE2 13058
13565 WRITEl 12982
13574 WRITE NEXT BLOCK! 13574
13594 OUTCHAR 13388
13604 LAST 16100
13611 FIRST 16101
13619 WRITE RANGE" 13619
13634 WRITE TAPE! 13634
13648 HEXl 12866
13655 CONVERT ASCII TO HEX! 13655
13679 HEX 12836
13685 READ 2 HEX DIGITS! 13685
13706 READ WITH CHECKSUM! 13706
13728 READHEX 12772
13738 ERROR AT" 13738
13750 READ3 12650
13758 READ2 12636
13766 BYTE 6
13773 ADDRESS 16101
13783 256 256
13789 NBYTES 5
13798 C 0
13802 READCHK 12726
13812 INCHAR 12884
13821 CHKSUM 0
13830 READ NEXT BLOCK! 13830
13849 READ1 12452
13857 VRFLAG 1
13866 VERIFY 12412
13875 V" 13875
13880 WRITE 12922
13888 W" 13888
13893 READ 12432
13900 R" 13900
13905 READ/WRITE/VERIFY/STOP" 13905
13931 BEGIN 12320 (cont’d on page 39)
Orthodontia, Box E, Menlo Park, CA 94025 Page 31
TINY .. FOR TINY BASIC
BY JOEL SWANK
4655 SW 142nd No. 186
Beaverton, OR 97005
Tiny GRAFIX is a system for graphic display on small
micro computer systems. It is composed of a SWTPC GT-6144
TV graphics board, Tom Pittman’s Tiny BASIC, and some
machine language subroutines. It runs on a KIM-1 with 4k
of memory.
The GT-6144 divides the TV screen into 6144 rectangles
in a configuration of 64 horizontally (X) and 96 vertically
(Y). It has its own 6144 bit memory used to maintain the
display. This memory is altered by data from the computer.
The data consists of X coordinates, Y coordinates and control
codes. Data is received via one eight-bit output port with data
ready strobe. The GT-6144 has no facility to send data to
the CPU. The GT-6144 is connected to KIM by the B port of
a 6820 PIA.
Communication with the GT-6144 is handled by a set of
machine langauge subroutines located at $200. They are de¬
signed to be used with the USR function of Tiny BASIC. The
following functions are provided: BLANK — Initialize the PIA
and the GT-6144 and clear the screen; ON — Turn on spot
at coordinates X,Y; OFF — Turn off spot at X,Y; FILL —
Turn on all spots on the screen; REVERSE — Reverse the
screen; CNTL — Send 1 byte of data to the GT-6144.
The USR function passes data from Tiny BASIC’s 16-bit
signed integer variables to these subroutines. The calling
syntax is shown in the comments of the assembly listing.
Only the low order byte of each parameter is used by the
subroutines. Subroutines ON and OFF do minimal checking of
the data for validity. With the CNTL subroutine a BASIC
program can send any value (0-255) to the GT-6144.
Tiny Graffer is a simple BASIC program that will graph an
equation of the form Y = f(X), where f(X) is any valid Tiny
BASIC operation. This equation is entered between fines
8000 and 8200. One value of Y is computed for each value of
X. Tiny Graffer requires 4 input parameters to scale the graph
on the screen. They are start value for X, increment for X,
low of Y range, and high of Y range. A good value for the
equation Y = X*X is -64,2,-100,4000. This results in picture
1. There is also the facility to do negative graphs (black
line on white background). This is done by changing line
1020 to P=579. Usually in 3 or 4 attempts input values can
be found that will produce a centered graph.
Tiny Pattern Generator takes advantage of the wraparound
nature of Tiny BASIC’s 16-bit signed integer variables to do
computer art. An equation of the form U = f(X, Y) is used to
control the pattern. The program computes U for every other
spot, and then based on present criteria either turns it on or
off. The variables H and L define the range for turning on
spots. A good range for most functions is L=500 and H=3000.
Very small numbers also turn on spots. H & L should be set
before the program is run. Every other spot is used instead of
every spot to speed up generation (Tiny BASIC is pretty slow),
and to provide a more pleasing display. Many interesting pat¬
terns can be developed with this routine. Pictures on this page
and the next are examples.
One problem with the GT-6144 is hard copy. About the
only way to get hard copy is to take a picture. To take a
picture the shutter of the camera must stay open for at least
1 raster scan of the TV (1/60 second). Instead of shelling out
for a camera with variable shutter speed it is possible to use
a Kodak instamatic camera (the cheapest one). The shutter
speed of this camera is not directly adjustable and the normal
speed is less than 1/60 second, but when a flash stick is inserted
the shutter speed slows to allow for less fight. So I cut the
plug-in out of a used flash stick and plugged it into the camera.
This slowed the shutter speed enough to allow the camera to
capture a full raster scan.
Because of its speed, Tiny BASIC can only do static gra¬
phics. These two programs only scratch the surface of what
can be done with static graphics. With a few fine or figure
drawing subroutines (in BASIC) and some imagination, sophis¬
ticated graphic displays can be produced by Tiny BASIC.
Page 32
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
457
0200 8F 02 re
e203 2e 09 02
0206 8C 02 re
020f. er 03 ce
020E FA
020F FA
0210 FA
0211 A9 39
0213 er 03 re
0216 60
re 80
A2 00
8F 03 ce
A 9 F F
8C 02 ce
A9 3C
8C 03 ce
20 00 02
re
C 0 F 0
dp Fe
A0 80
E 8
Fe 40
C0 F 1
A2 F 1
86 F0
Ae F4
20 00 02
60
CSP : HRAFIC bUFROUTINE PACKAGE
TINY TASIC INTERFACE VEHSION
FUNCTION :
TO PROVIDE AN INTERFACE FOR THE SWTPC
6144 TV CRAPHlCb POAHD. THE PC ARD IS
connected via the n port of a 6820 pia
LOCATED AT MEMORY LOCATIONS 0802
(CATA REGISTER) AND 0803 (CONTROL
REGISTER). IT ALSO USES CONTROL HIT
2 FOR CATA OUT PULSE.
TINY FASIC CALLS
TLNK : INIT PIA AND CLEAR SCREEN
P-USR(539)
cn : turn on spot x,y
P-UbR(577,Y,X)
OFF : TURN OFF SPCT X,Y
P-USR(579,Y,X)
FILL : TURN ON ENTIRE SCREEN
P.USH(609)
RVRb ; REVERSE THE SCREEN
P-USR(596)
CNTL : SEND X TO 6144
P-USR(518,X)
CRC $0200
ZERO PAGE STCRACE
REVR * $ 0 0F 0
EXTERNAL LABELS
0ATB * $0802
CTLF * $ce03
CETK * $ IF6A
TVCUT ; SUBROUTINE TC SEND DATA FROM
X & Y REGISTERS.
TVCT
STX
T ATB
SEND X
JSR
TOGO
PULSE
SENC
1 BYTE
CNTL
STY
DATE
SEND Y
TOGGLE s SEND PULSE ON CONTROL FIT 2
TCCG LDAIM $34
STA ctlb CONTROL LINE LOW
NOP
NOP OELAY SOME
NOP
LDAIM $ 3C
STA CTLB CONThOL LINE HI
RTS
FLANK : CLEAR ENTIRE SCREEN
CLNK LCYIM $80 INITIALIZE PCRT TO OUTPUT
LDXIM $00
ST X CTLB
LDAIM $FF
STA CATE
LDAIM $3C
STA CTLB
WRIT JSR TVCT CLEAR A BYTE
INY NEXT Y
CPYIM $ F 0 END CF LINE?
BNE WRIT NO
LDYIM $80 HE-INIT
INX NEXT X
CPXIM $40 END CF LINE?
TNE WRIT NO
LDXIM $E1 NORMAL SCHEEN
STXZ REVR SAVE STATUS
LDYIM $F4 ENABLE CHAPHICS
JSR TVCT SEND
RTS
TURN CN SPCT
093 0: 0241 09 40 CN CRAIM $4e CN ‘’IT
0940: TURN CFF SPCT
0950: 0243 29 7F CFF A.NDIM $ 7F LIMIT
0960: 0245 AA TAX
0970: 0246 C0 60 CPYIM $60 Y IN RANGE?
0980: e24e 90 02 CCC YOK YES
0990: 024A Ae 5F LDYIM $5F CLIP
1000 : 024C 9e YOK TY A
1010: 0240 09 80 ORAIM $e0 INDICATE Y
1020: 024F A8 TAY
1030: 0250 2e 00 02 JSR TVCT SEND
1040: 0253 6e RTS
1050 :
1060; REVERSE : SUBROUTINE TO HEVERSE THE SCHEEN
1070 :
1080 :
0254
A 5
Fe
RVRS
LDAZ
REVR
GET CTL BYTE
1090:
0256
49
01
FCRIM
$0 1
TOGGLE BIT '/>
1100 :
025e
e5
Fe
STAZ
REVR
SAVE
1110:
025 A
80
02
cn
STA
DATB
SEND
1120 :
02 5 C
20
09
02
JSR
TCCC
PULSE
1130:
1140 :
0260
6e
hTS
1150: FILL
1 160:
1170: e261 A2 40 FILL
1 1G 0 : 0263 A.0 60 f.EWY
1190: 0265 20 00 02 WRT
i2ee : 026C ce
1210: 0269 C0 F0
1220: 0260 T0 re
1230: 0260 FP
1240: e26F F0 B0
1250: 0270 00 FI
1260: 0272 60
TS.
: SUBROUTINE TC TURN CN ALL
LDXIM $40 INIT COORDS
lcyim $ee
JSR TVCT SEND THEM
INY NEXT Y
CPYIM $Fe END CF COLUMN?
f NE WRT NO
I NX NEXT X
cpxim $ee cun?
ONE r.EWY
RTS
SYMBOL
TAELE
320C 3260
CLNK
0217
CNTL
0206
CTLB
cec3
CAT B
0802
FILL
0261
cetk
IF 6A
NEWY
0263
OFF
0243
ON
0241
REVR
0 CE C
RVRS
0254
TOCG
0209
TVCT
02eo
WRIT
0228
WRT
0265
YCK
024C
: L 1ST
1000 REM TINY PATTERN CENEHATOR
1010 A.USR(535)
1020 Y-0
1 e30 X-Y-( Y/ 2*2)
1040 GCSUB 8000
1050 IF U<-12000 A-USH(577,Y,X)
1060 IF U>L IF U<H A-USR(577,Y,X)
1070 X-X+2
1080 IF X<64 GOTO 1040
1085 Y.Y+1
1090 IF Y<96 CCTO 1030
1100 PR "FYE"
1110 END
6000 REM THE PATTERN CENERATION FUNCTION GOES HEHE
8100 U-X*X*X/7-Y*Y/ 9+X*Y-X*X/8+Y*Y*Y/ 13
820e RETURN
:L 1ST
ieee rfm tiny chaffer
1010 REM
1015 REM SET P-577 FOR PCSATIVE GRAPH
1016 REM SET P-579 FOR NEGATIVE CRAPH
1020 P-577
1025 RFM INPUT X-START, X-INC, Y-LOW, Y-HIGH
103e INPUT S.T.U.V
1035 RFM CLFAR SCREEN
104e A-USH(535)
1045 RFM FILL SCREEN IF NEGATIVE CRAPH
1050 IF P-579 A-USR(609)
1055 REM COMPUTE Y INCREMENT
1060 N-(V-U)/95
1070 X-S
1080 L-0
1085 HEM COMPUTE VALUE
1090 cosub eee0
1095 REM SCALE RESULT
1100 Y-(N/2-U+Y)/N—1
1105 REM CLIP AT EDGE CF TISPLAY
1110 IF Y<0 CCTO 1150
1120 IF Y>95 COTO 115e
1125 REM DISPLAY VALUE
1130 Y-95-Y
1140 A-USR (P , Y , L )
1150 X-X+T
1160 L-L+1
1165 REM NEXT X
1 17e IF L<64 GOTO ie90
1180 PR "BYE”
119e END
8000 RFM The FUUATION TO PE CRAFFED COES HERE
8100 Y-X*X
8200 RETURN
Number 30
458
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 33
The STD Bus:
A Critical Look at a Proposed New Standard
BY KEITH BRITTON
P.0. Box 6214
Hayward, CA
Recently Mostek and Prolog jointly announced a new bus.
Such announcements appear from time to time, generating
close scrutiny from a handful of intensely interested parties,
mild curiosity from a somewhat larger and mostly hardware
oriented group and, from most of the rest of us, no more
than dull resentment at the need to increment our files of
dubious mnemonics and ill chosen acronyms. The STD bus
may well repay somewhat closer attention, for a surprisingly
wide variety of reasons. STD is an abbreviation of the word
standard and the principal importance of the bus lies in its
proponents’ attempt to create a widely adopted standard
rather than to merely launch a product line. Few observers
will fail to find something of interest in the resulting inter¬
play of politics, economics, history and tradition (distinction
intended), mechanics, engineering decisions and tradeoffs,
software/firmware/hardware interactions, logic, individual and
corporate personalities. And, for those addicted to private or
professional meditation, there is not only room for considera¬
tion of the immediate and future technological impact of the
new bus but also of some subtle sociological implications as
well.
The Bus — General
A bus design is probably best considered top down. That is
to say from the general logical content through the specific
logical meaning of signals to their electrical and mechanical
expression. As proposed, the STD bus is a simple synchronous
bus with an eight bit data path separate from a sixteen bit
address path. The necessary control signals are also simple
and distributed one per bus line. Thus the overall philosophy
of the bus is to accept limitations while gaining simplicity,
but there is also an attempt to fit the bus to a variety of eight
bit processors and to make token provision for memory and
I/O expansion. The read/write controversy is resolved on the
separate line side, an exception to the general air of frugality.
The economy of lines (56) used by the STD bus is not only
a distinguishing feature but also a significant selling point.
Every line which must be supported exacts its economic toll
in bus drivers and buffers and in printed circuit board area
for both motherboard and cards. This may not be a disadvan¬
tage for a complex high unit value computer, nor for highly
flexible hobby/development systems as in the S-100 bus.
However, for the more price-conscious industrial control/light
data processing market at which the STD is aimed, the fewer
pins the better. Perhaps even more important, for equipment
aimed at industrial environments, is the reduced difficulty
experienced in maintaining reliable bus operation and reduced
power requirements, especially where line termination is
employed.
As a practical matter, the number of lines also determines
the pin spacing and contact areas, which also impact econo¬
mics and reliability. Contact pins on .156 inch centers, as in the
common 44 pin standard sockets, allow the design of cheap
but excellent motherboards. Signal traces may be heavy, and
therefore of low impedance, and there is plenty of room
between signal traces for ground line shielding. Power supply
is unlikely to be a problem thanks to the substantial contact
area of the power pins. A motherboard capable of reliably
handling state-of-the-art data rates can thus be produced as
a simple double sided PC board and manufactured by a
marginal board house. In contrast, a comparable motherboard
for connectors in .1 inch spacing is a work of art and expen¬
sive. The .125 inch spacing used for the STD bus represents an
engineering compromise between these extremes. As such it
offers some rewards for good design but threatens significant
penalties for bad.
Card Size and Shape
STD bus advertising stresses the card size, and for good
reason. A system using many small cards, as used by Control
Logic Corp., incurs significant expense in connectors and
buffers. Increase in system size and complexity leads to
awkwardly shaped card cages, and motherboards so long as to
present formidable difficulties for high speed data. Systems
with comparatively large cards, such as the SBC 80 and LSI
11, economize on connectors, buffers and bus lengths but at
the cost of increased card complexity and expense. In addition,
enclosures for large cards are generally expensive and may be
mechanically weak. Large cards are both inherently more dif¬
ficult to support and more difficulty to thermally control.
STD cards are 4 'A inches wide and, as standard, 6 X A inches
long. Supported along their long sides, they are well adapted
for use in rigorous environments. They also represent a com¬
promise in terms of card area, which make them well suited
to their market. System maintainability is critically dependent
upon module size, as is first cost, though to a lesser extent.
Large, complex multi- function cards significantly impact
first cost unless all functions are used, and impact maintain¬
ability in that failure of any card function is likely to result
in complete card replacement. STD cards will be typically
single logical function, encouraging board swapping trouble
shooting, reducing spares inventory, and keeping initial system
cost aligned to functional requirements.
The small work area of the STD card produces some
problems however. While it can certainly accept as many as
48 chips for a dense arrayed card such as a memory board,
Page 34
Or. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
459
even excellent printed circuit layout will not allow densities
equivalent to much more than 30 chips for more randomly
arranged circuits. For this reason, skill in printed circuit board
design will be at a premium for this bus. Note, however,
that this applies only to the standard STD card size. Unlike
other buses, the STD has the potential for being compara¬
tively flexible in its card area. The 4Vi inch width of the card
fits a very wide variety of standard enclosures, and while the
most popular is certainly the 6 Vi inch length, other lengths
are supported most notably the 9.6 inch. This latter offers
roughly double the effective work area, that is the total area
less buffer area. Even longer cards, though possible, are un¬
likely as the resulting card cages become mechanically poor
and circuit board layouts become increasingly inefficient
due to the increased aspect ratio.
An interesting comparison may be made between the STD
standard card and its probable extension and the Eurocard
system. The small Eurocard is roughly 4 inches by 6 inches
(100 x 160 mm). Unlike the STD card, it is fractionally too
narrow for two 40 pin dip chips to be aligned crosswise, a
surprisingly significant layout disadvantage. Its effective work
area is only some two-thirds that of the STD cards which,
combined with its less advantageous aspect ratio, will in
practice nearly double the number of small Eurocards com¬
pared to STD cards required for an equivalent system. Since
increasing the area of the Eurocard by increasing its length
would incur very substantial aspect ratio layout inefficien¬
cies, the Eurocard area expansion is done by increasing the
width, resulting in a disastrous economic disadvantage for
small systems. The larger cards require two connectors rather
than one, use different motherboards, different supporting
chassis, and large and small boards cannnot be intermixed
in a single system. If the STD bus does in fact become the
standard for industrial electronics within the United States,
this comparative flexibility may prove to be a significant,
perhaps even crushing, advantage over its European com¬
petition. And with the advance of the metric system within
the US, existing cards will fit a 115 millimeter card guide
spacing with 175 millmeter and 250 millimeter card lengths.
Power
The principal logic power supply is 5 volts supplied with
off-card regulation to avoid local heat concentration. Two
bussed pin pairs are provided at one card edge to allow both
ample contact area and room for motherboard traces of un¬
limited area. At the opposite end of the card single opposed
pins supply a nominally analog plus and minus 12 volts. This
supplies, though with limited contact area, the 24 volts likely
to be needed for industrial controls. Power is more likely to be
contact area limited than trace area limited since the pins
concerned are the outboard pins on the connector, allowing
unlimited trace room. The ground return for these pins, which
need not be logic ground, is more limited physically, but this
is partly compensated for by use of two bussed pins. Both
sides of the board may therefore be used with heavy traces
and, if desired, extra area may be used between sockets at
the expenses of the power lines to reduce impedance.
Up to this point, the power supply and distribution can be
considered beyond reproach. The remaining power supply
blows two more precious pins on minus 5 volts. This eyebrow
raiser becomes even more curious when one realizes that the
pins are specifically not bussed and that at least one of the
bus proponents does not propose to supply this power level
for standard systems. This curiosity comes about for partly
historical and partly corporate policy reasons. A draft of the
bus dated in May shows the two pins concerned as undefined.
Corporate policy then required that no pins be left unassigned
and it seemed possible that minus 5 volts could prove a useful
substrate voltage, particularly for use with dynamic memories.
Although this possibility later receded, no one could think
of anything useful to do with the pins so both were assigned
to an unwanted power level, the primary function of which
is to discourage ultimate use of the pins concerned, leading to
the pointed question—What is the STD bus standard? Either
an STD bus designer has a right to expect an STD compatible
supply to supply this power level, or the STD bus may well
be headed down the road pioneered so well by the S-100.
Bus Lines—Address/Data
As proposed, the STD bus has eight data lines and 16
address lines. Data lines are bidirectional and all lines are three
state. This is the classic arrangement for a synchronous eight
bit processor and is unsurprising since the Prolog customer base
buys four bit and eight bit processors and Mostek, which
was unable to second source the Zilog Z8000, offers no
processor larger than eight bit. The absence of any system for
multiplex use of the bus and/or wider data paths is highly
regrettable and the biggest reason why this bus should not,
as it stands, become a national standard.
Multiplex operation is becoming increasingly common and
for good reason. For memory parts, multiplexing roughly
halves the number of pins required, significantly reducing
direct costs and dramatically reducing the printed circuit
board area required and this is of great importance to small
cards used in the STD bus. Similar advantages, though less
marked, are realized for CPU and other support devices, and
this has led to multiplexing, originally considered only applic¬
able to 16 bits and up, to extend downwards into the 8 bit
field, notably with the support line for Intels 8085. There is,
therefore, a good argument for multiplex capability on the
STD bus even if the bus is to be considered restricted to 8
bit operations.
To allow synchronous and multiplex cards to coexist
within a single machine would require only two lines to be
used for multiplex operation control. Obvious candidates
would be the minus 5 power lines. Adding this capability
would greatly increase the flexibility of the bus since multi¬
plex processors could still use synchronous cards by demulti¬
plexing at the processor card buffers. In addition, the addition
of multiplex capability would allow the use of wider data
paths—up to 24 bit. At first glance this may seem unneces¬
sary or even undesirable for small systems and systems
particularly designed for industrial control use. It must, how¬
ever, be realized that PDP 1 Is, Novas and even more power¬
ful processors have long been commonly used for industrial
applications for which 8 bit machines prove inadequate. A
national standard based on the STD bus could perfectly well
support the Motorola 68000, the Intel 8086 and Zilog Z8000
as well as a wide variety of 8 bit processors. This would allow
the user to maintain a high degree of compatibility amongst
his most common cards, which will always be predominantly
8 bit I/O cards.
Number 30
460
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 35
Memory I/O Control 31-36
Four of the six lines are quite straightforward, separate
read and write lines plus two lines for memory or I/O select.
The remaining two lines are designated for memory and I/O
expansion, one line for each. Enquiry, however, reveals that
although Prolog and Mostek are in accord as to the designa¬
tion of these lines, neither has as yet formulated a scheme for
actually implementing expansion. This provides another can
of worms, since the implementation chosen will impact
software, firmware and hardware. Expansion capability may
be used in two ways. The most obvious is to simply extend the
number of I/O devices or memory locations which may be
addressed. Less obvious, but for engineering applications
possibly more significant, is the ability to use alternate
memory locations or I/O devices. This is best illustrated by
considering the latter.
A subroutine using absolute I/O addresses may, given
alternate bank capability, be applied to more than one set of
I/O devices by simply swapping banks, with implications for
both hardware and software. Memory management, for pro¬
cessors not designed for page mode operation, is more of a
problem. One means of implementation would be to treat
the memory expansion line as the 17th bit to be decoded on
each memory card. This would required each memory card
to be burdened with the necessary decoding logic, a small
but significant expense and penalty in precious PCB real
estate. A second system might be to AND with memory
request or the enable from the address decode, which has
similar disadvantages. Another system is to allow optional
jumpering on each memory card for memory request and to
issue memory request upon the appropriate line at the proces¬
sor. Similar considerations apply to I/O cards. This latter
scheme involves negligible expense or real estate penalty,
other than on the processor card, and has the advantage that
since all four lines are conveniently grouped, a simple jumper
or switch arrangement allows any desired mix of memory
I/O expansion. This latter flexibility would have one disadvan¬
tage. Fewer devices could be controlled in this manner than
could be controlled using the two expansion lines as address
extensions. But memory and I/O cards are not the only ones
to be considered. Extended memory or I/O could be managed
from the processor card or from a separate management card
addressed by the processor via I/O instructions.
Actual implementation for memory management is not
as simple as it might appear at first glance. The CPUs to be
used were not designed for such duty, and it may entail
some curious and amusing oddities in bit hardware and soft¬
ware. Consider the case of a CPU which is swapping memory
pages by issuing an I/O instruction. The next instruction
fetch will be from the “new” memory page, and from what¬
ever byte the preceding I/O instruction left the program
counter pointing at. Transfer between pages of ROM can thus
require some care in coding while transfer between pages of
writable memory, assuming one has succeeded in achieving an
initial beachhead, could add a novel dimension to self-modi¬
fying code. Equally amusing, although unattractive, is the
thought of dribbling data back and forth across boundaries,
hand carried in registers.
This nonsense can be alleviated by processor card logic
which arbitrates read, write and instruction fetch between
designated memory banks. Other methods are also tenable,
but again, in the absence of a defined standard covering
logical approach, addressed board hardware and software
techniques, and management device address, it is hardly proba¬
ble that any two manufacturers for the new bus will achieve
mutual system compatability.
The Control Group 37-46
Six of the ten signals are straightforward implementations
of logical requirements—bus request and acknowledge to allow
multiprocessing or DMA, maskable and nonmaskable interrupt
request with interrupt acknowledge allowing one level of
interrupt priority but requiring vectoring for further interrupt
expansion, and wait request for slow devices. The remaining
four lines are more questionable from the point of view of a
national standard.
Refresh is a frankly Z80 signal, though Prolog documenta¬
tion states that it may be supplied from a specific purpose
card. Standardization upon a processor dependent signal,
or mimicry thereof, is at best questionable, but there is worse
in store. Pin 38 turns out not only to be defined in terms of
specific hardware, but also in terms of the manufacturer’s
specific product line, and mutually incompatible products
to boot. Prolog defines this pin as machine cycle sync for the
convenience of the bus analyzer it sells (note that this is NOT
the sync associated with an instruction fetch). Mostek calls
the line by a different name and uses it as a hardware single
step controller. In justice, it has to be admitted that this is
not inconsistent with the general tone of this proposed
standard. Paraphrased: “Manufacturers shall adhere to a
universal standard except that they shall note in their litera¬
ture where they deviate therefrom.” In this instance it is
unclear whose definition is the STD bus definition, but there
is a good argument that neither should be. Nor is this the only
signpost pointing to the road pioneered by the S-100.
At Wescon Prolog showed its 7000 series STD cards while
Mostek showed its STD-Z80 cards. The Z80 has no separate
pin for interrupt acknowledge, the logical signal being pro¬
duced by an AND of the instruction fetch sync signal, Ml, and
I/O request. Both companies issued this logical signal from the
CPU card to the appropriate bus line. The I/O card usage
differed, however. Z80 peripheral support chips requiring an
interrupt acknowledge are designed to decode directly from M1
and I/O request. Mostek cards reportedly did just that, ignor¬
ing the bus line intended for the purpose, which was the line
usd by Prolog I/O cards. Prolog I/O cards will therefore work
with Mostek processors and vise-versa, but this is only true
for Z80 processor boards and Prolog proposes to offer 6800
and 8085 boards almost immedately. Caveat emptor.
The remaining two signals of this group are titled CPU
status 0 and 1. CPU status 1 is used for any signal identifying
an instruction fetch, Ml for the Z80. The remaining line,
unused by Mostek, is used by Prolog for SO for the 8085 and
VMA for the 6800. In general the clarity, precision and com¬
pleteness of definition for these lines—again bearing in mind
that the companies concerned are proposing the STD bus as a
national standard—is perhaps best illustrated by these words
from the Prolog draft of the bus manual. “The status control
lines are used to provide timing information related to special
machine cycle operations. Where it is specifically available
status 1 is considered to be a signal to identify instruction
fetch.”
Page 36
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
461
Reset
All computer systems need a reset line. The STD bus has
two. One is a short, clean, debounced signal for use by TTL
logic. The other blows one of the few precious lines available
merely to communicate an external push button closure to
whichever bus resident card supplies the former signal. Power-
on reset and debounced external push button reset can per¬
fectly well be handled on the motherboard, and/or at the
switch, saving a line and/or a slot and/or CPU card real estate.
If a second reset line is to be provided, for engineering pur¬
poses it may be better employed as an addressed reset, which
would allow the processor to reset a card by issuing the reset
and the card’s I/O address. This would avoid the necessity of
issuing a general system reset / and, since it would reuse the
address decode already available, avoid issuing multiple reset
commands or committing additional I/O addresses for the sole
purpose of implementing local reset functions.
Clock 49 and 50
The STD bus has tow lines for clock signals. One is the
processor clock and the other is available for alternate system
use. This will allow slow speed devices to use a common clock,
a simple and effective arrangement.
God Is On My Right 51 and 52
The STD bus is unusual in defining two pins for daisy chain
operation. These pins are not bussed, but connected 51 to 52
along the motherboard. Implementation of daisy chains is
therefore greatly simplified since adjacent cards may control
each other and priority is simply established by physically
positioning the highest priority card to the right of the next
highest and so on. This will prove a great convenience for I/O
operations, interrupt driven applications, and possibly for
implementation of multiprocessors.
An Opportunity
The STD bus, as presently proposed, is a competently de¬
signed synchronous bus for eight bit processors unusually well
suited to its putative market—engineering and light data pro¬
cessing. But incompatibilities exist even amongst the earliest
cards, bus definitions are often fuzzy (and at least one case
mutually incompatible) and no apparent consideration has
been given to a support or policing system capable of estab¬
lishing discipline amongst nominal bus suppliers. Based on the
above, a reasonable prognosis for the bus would appear to be
islands of very good engineering in a shambles comparable to
the S-100. Nevertheless, the potential exists for the STD bus
to become a well controlled system of complex building
blocks of truly extraordinary versatility—the 7400 series of
the microcomputer world. This can reasonably be achieved by
a hardware change, a policy change and an organizational
development.
The hardware change is the definition of two bus lines for
control of multiplex operations, preferably by junking the mi¬
nus 5 volt power. This would open the bus to the new 16 and
32 bit processors and would allow use of the new generation
of 8 bit support devices.
It has been the policy of the original STD bus proponents
to define all lines of the bus in what is already exposed as a
futile attempt to avoid anarchy. Fortunately, this untenable
policy is capable of simplification and rationalization. If the
bus be considered from a top down design stance, it will be
immediately obvious that certain signals should be expressed
within the bus architecture because they are logically
necessary or extremely desirable for computer operation. In
this category fall the address and data lines, read, write,
memory and I/O select, bus request maskable and nonmask¬
able interrupt (with acknowledgements), wait and reset. These
signals should be supplied and used, to the exclusion of alter¬
natives, for their logical purpose by all suppliers to the bus. Of
lesser importance is a second category of contenders for bus
space, commonly used and highly desirable conveniences. In
this category fall the processor clock, instruction fetch identi¬
fication and daisy chain system.
The remaining single lines on the bus, having failed to
justify their inclusion in either general category, should be
considered as utility lines and defined as such. This is no bar,
of course, to multiple definition. Line 37 could, for instance,
be defined as refresh/utility. Thus refresh, if implemented,
must appear on that pin and no other. The physical implica¬
tions for this approach are trivial, merely that to accommodate
the dual or multiple use potential of such lines, no permanent
connection be made to the pins concerned. This requirement
may be simply met by use of a jumper or a prepared trace
separation point, a necked down portion between two pads
usable for repair. STD bus designers, and more importantly
users of same, could thus enjoy a high degree of flexibility
while maintaining, for the bus fines of primary importance,
standards of such rigidity as to preclude basis system incom¬
patibilities.
No standards wll be observed without discipline. To apply
it, the STD bus needs a watchdog. Industry watchdogs tend to
be toothless, but in this case the situation is unusual. The teeth
are obvious but the dog is not. For the market at which the
STD bus is aimed, adequate commercial coercion can be
simply applied by withholding use of a trademarked logo for
products which do not meet established standards. Hobbyists
will buy an off brand article but industrial purchasing agents
will not. Proof—when did you last see a non-UL approved
appliance in an office? There are a number of obvious pos¬
sibilities for a regulatory body, JEDEC, ANSI, and IEEE to
name but a few. None are noted for snappy footwork under
pressure, blinding speed in their committee work or evident
desire to expose themselves to the muck raking and flak den¬
sity which may be reasonably expected. The organizations
named might, however, be persuaded to nominate board mem¬
bers to an association of STD bus manufacturers set up for
standards development and maintenance.
Such organizations are not without precedent and much
might be adapted from the commissioner oriented forms of
organization developed to police national sports. In addition
to its regulatory function, such an organization could perform
an invaluable service to manufacturer and customer alike as a
central information source for the bus. Available information
could include second sources, plug compatible sources, func¬
tional equivalents and near equivalent alternatives. Incompat¬
ibilities and cautions could be flagged, as could existence of
application notes or other useful references. In addition, cross
Number 30
462
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 37
referencing could be done to sources of related items such
as STD width enclosures and solid state relays and transducers.
And this information could be easily made available on a 24-
hour basis for the price of a microprocessor, a disk and an
answer modem.
Futurebus
The IEEE has committees working to straighten out the
S-100, rationalize microprocessor bus interfacing and, signifi¬
cantly, to study, anticipate (and hopefully in some measure
ure to direct) future developments. Since we may be abso¬
lutely certain that the STD bus is not the ultimate bus, it may
be well to consider its probable lifespan and the changes which
may occur to it within the near future. A number of techno¬
logical trends are already sufficiently well defined to allow
extrapolation. At the risk of belaboring the point, an obvious
trend is towards multiplexing. It seems reasonable to suppose
that the STD bus will have limited scope and/or limited future
if it remains synchronous and, since a trend is also fairly ob¬
vious toward wider data paths, if it remains 8 bit.
Interface and I/O support chips become ever more complex
while simultaneously single chip microcomputers gain in
power and richness of built in I/O devices. To some degree
these trends are convergent and are likely to impact the STD
bus in two ways. Increased chip complexity will reduce de¬
mands from printed circuit board real estate, a definite plus
for the STD compared to its competitors. But the trend will
also be to distributed intelligence and array processing. This
will place an increasing premium on bus architecture factors
favoring multiprocessor or distributed intelligence use. Since
the STD bus was not designed with this in mind, its present
architecture could prove to be a blind alley. Presently, how¬
ever, distributed intelligence and its problems remain but
poorly understood.
Trends in memory toward increased speed and density
at reduced cost appear unlikely to significantly affect STD
machines used for engineering purposes as such applications
tend to require little memory. For data processing applications
of STD machines, unless multiplexing opens up all 24 address/
data bits for address use, the present single designated memory
expansion pin will prove totally inadequate to prevent the bus
from reaching rapid obsolesence.
The remaining major question mark for the future of the
STD bus results from a quite evident trend which has, to date,
been relatively unremarked. In the past processors have
radiated a wide variety of status and timing signals usually
using a pin for each. A move away from this practice is a
recurrent theme for the most recently developed CPUs particu¬
larly the Intel line. The signals may still be available redun¬
dantly at individual pins, but all necessary signals are likely to
be recoverable from a small group of encoded status lines.
This makes so much sense in terms of reduced pin count,
board and bus complexity, as to be clearly the way of the
future. Consider the STD bus. Every status or control line
emanating from the processor could be replaced with a block
of four encoded lines, and there would still be space in the
encoding for multiplex control and I/O and memory expan¬
sion. True, each card would then be burdened with decoding,
but this would merely involve a simple mask ROM with four
inputs configured as bus buffers, hardly more expensive than
the buffers required for the present arrangement. Presently,
the bus proponents intend that it should be a living thing and
adapt to technological change. Production lines have a certain
inertia as do customers. Probably significant changes could
be made within the next two or three months, present com¬
mitments being still limited, and hopefully this opportunity
will be taken to immediately make changes which cannot be
long postponed. Flexibility and change are essential to avoid
ossification, but one should bear in mind Borge Langefors’
fifth principle—“If the time it takes to implement a change in
a system is longer, on the average,than the mean time between
changes, then the system is not viable.”
Who Will Salute?
Reference to the Oxford English Dictionary reveals three
senses for the word “standard.” Firstly, a standard is a rallying
point. The present burning question in several board rooms is
simply —who will climb aboard? Without wide support, the
STD bus will not become a standard, nor will it become a sig¬
nificant market place. It may be reasonably expected to
attract a substantial number of very small manufacturers
because it is the only game in town for the commonly used
card size. Many cards, thanks to the bus’s philosophy of com¬
petent solid simplicity, will be fitted to the bus by mere
pinout reassignment. It is possible, however, that Mostek and
Prolog may have more difficulty in attracting to the bus com¬
parably substantial full line competition. Implementing the
relatively minor modification necessary to allow multiplex
and multibyte bus operation could significantly alter this
position, particulary since there is no evidence as yet that two
giants and one bigee, Motorola, Intel and Zylog, have yet
committed to a bus for their wide processors.
A Good Measure?
The second sense of the word standard is that of a measure.
Would, or could, the STD bus become a good or bad standard?
and further, would the wider implications of such a standard
prove generally beneficial or detrimental? As proposed, the
STD bus seems far too limited to have the significant impact
necessary to generate a market segment standard, let alone
a national or international one. On the other hand, as pro¬
posed it already contains the bulk of the features likely to
be needed for at least the next decode and has no obvious
bar to adopting the missing ones.
The IEEE owes a particular debt for its future bus studies
to Hermann Schmid, who recently kindly supplied this author
with a paper titled “A Top-Down Approach for Monolithic
Processor Standardization,” containing his current thinking
on the subject. His focus has been particularly upon the mid-
80’s, but the paper exhibits an almost eerie correspondence
with the opportunities open to the STD bus and its propo¬
nents. For the STD bus, and by extension the segments of
industry and humanity directly or indirectly impacted, the
future could be now.
Microprocessor building block standardization could pro¬
foundly affect the widespread application of artificial intel¬
ligence. But this is a more serious business than merely the
drastic cost and development timesaving which might be
expected to parallel that shown, on smaller scale, by the stand-
ardiation of the 7400 TTL series. Microcomputer standardiza¬
tion has to be seen in historical perspective, and a striking
Page 38
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
Number 30
463
analogy can be made with the British of 200 years ago. America
is leading the way in a revolution far more profound than the
Industrial Revolution. Where the British, during the Industrial
Revolution, extended man’s muscle with inanimate power,
Americans are today extending man’s mind with artificual
intelligence.
From the engineering anarchy of the early Industrial
Revolution certain standards emerged, some to become,
for economic reasons, immutable. For instance, the British
bequeathed the world a standard railway gauge of 4’ 814”
for no better reason than that a few miles of existing haulage
road being adapted for railway use had timbers convenient
for that spacing. Pressures for standardization are increasing
so rapidly that it seems hardly likely the next decade will
not irretrievably commit our descendants. The STD bus will
not be the ultimate bus, but it deserves careful consideration
and perhaps support if only because of its potential as a proto¬
type or test bed capable of at least enlightening possibly
irrevocable technological decisions which we cannot long
evade.
A Thing Erect
The third sense of standard is that of a thing erect-which
may lead cynics and those familiar with the traditions of the
industry to suspect a digit. Neither of the original STD bus
proponents claims to be other than a commercial organiza¬
tion and out to make a buck. It is seldom reasonable to criti¬
cize manufacturers for introduction of a product line contain¬
ing features peculiarly adapted to their advantage, but by
proposing the STD bus as a standard, Mostek and Prolog have
exposed themselves to judgment in more than simply com¬
mercial terms. The usage of pin 38 is clearly self-serving
and hardly in accord with a spirit of standardization. There is
also evidence, particularly related to the minus 5 power
supply pins, that the companies concerned have been willing
to accept at least questionable engineering decisions, in an
unseemly haste to lock up all pins, and create a defacto stan¬
dard. Interestingly, the smaller company, Prolog, has adopted
the more intransigent take-it-or-leave-it stance. Development
of a new bus is, or should be, a problem orders of magnitude
greater than can be indicated by this somewhat cursory
article, and is a subject which has engaged increasing attention
from many fine minds. In particular, the IEEE committees
studying bus related matters are an obvious resource and
reference point. Presently, this author has been unable to
trace any attempt by Prolog and Mostek to consult such
resources or to apprise them, in a timely manner, of their
intentions. A prima facie case thus exists to indict both
companies for at least irresponsibility, in the context, it must
be emphasized, of the STD bus proposal as a standard.
Judgment on this issue would, however, be premature,
since the companies clearly do not yet have their joint act
together and their proposed bus may turn out to be more of
an asking bid than a fait accompli. If this proves to be the
case, history may record substantial indebtedness to them
for short-circuiting years of tedious committee maneuvering
by developing the small system standard for the 80’s to the
point where adoption is swiftly possible with but minor
changes. And the sense of erectness may well be associated
with the names of Mostek and Prolog—for stature that has
hitherto been often lacking amongst the industry’s leaders.
13939 STATUS 3 (cont’d from page 31)
13948 TAPE 2
13955 ANSWERS 6 S
13970 INTEL FORMAT TAPE ROUTINES! 13970
13406 ?
Other Applications of BASEX
The BASEX manual includes a very useful sample program
that allows you to convert numbers from any number base be¬
tween 2 and 36 to any other base and do arithmetic (+,-,*,/)
or logical operations (&, #, %) in any number base. This 1K-
byte program will do everything the $60 TI Programmer cal¬
culator will do and more! I have also converted that chess pro¬
gram and the Bulls and Cows game into BASEX; both run
about 10 times faster than they did in BASIC. That factor of
10 is the difference between fun and boredom. BASEX was
also ideal for writing a powerful word processor that I call
PRO-TYPE (see below). In order to use my North Star disk
and Meca tape drives with BASEX programs, I have written
some utility routines that permit random or sequential access
to disk or tape files, etc. These things have a way of eating up
time, so the interactive graphics and electronic music programs
haven’t yet been translated to BASEX, but someday ...
Hardware Requirements and Availability
The current version of BASEX was written for the 8080,
but it also runs on Z80 or 8085 microcomputers. However, it
is fairly straightforward to translate the 2K bytes of run-time
subroutines to ran on other microcomputers. Since the
BASEX compiler and LOADER are written in BASEX, they
should work with minor modifications on any other micro¬
processor, once the run-time subroutines are available. It
should also be very easy to translate any user application pro¬
grams from one dialect of BASEX to another. The conversion
for the 6502 is already underway and if there is sufficient in¬
terest, BASEX may be made available for other microproces¬
sors, as well. A second limitation of the current version of
BASEX is that it resides in the lowest 8K of memory (loca¬
tions 0 to 5 and 64 to 1FFF), which presently precludes its
use with some computers that have ROM down there (e.g., the
Radio Shack TRS-80, Heath H-8).
The BASEX manual is being published by Byte Publica¬
tions, Inc. and will be available from them or from your local
microcomputer store. It includes a more detailed explanation
of each command, sample programs and fully commented list¬
ings of the assembler language run-time subroutines, the com¬
piler and the relocating LOADER program. A full explanation
of how the BASEX user can add his own customized com¬
mands to BASEX is included in the manual. It also contains
the object code for these programs in bar code format. For
those of you who want to be the first on your block to try
BASEX, I have a limited number of copies of the preliminary,
unedited version of the manual available for $10. North Star
disks or Meca tapes containing all of the programs are available
for $25 from Interactive Microware, Inc., 116 South Pugh
Street, State College, PA 16801. Other disk and tape formats
will also be available as soon as possible. This company also
markets the program that allows BASEX programs to access
North Star disk or Meca tape drives and the PRO-TYPE word
processor, which is written in BASEX.
Number 30
464
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 39
COPYING A DISKETTE ON
INTEL DOUBLE DENSITY DOS
BY PAULM. JULICH
Dept, of Electrical Engineering
Louisiana State University
Baton Rouge, LA 70803
The program presented allows one to copy track by track
all blocks of diskette regardless of attribute. The program runs
considerably faster than the INTEL supplied program using
ISIS Commands for copying files. A complete diskette can
be copied in 2 minutes, 45 seconds.
An added benefit is that the copied disk is identical with
the original. In other words corresponding blocks will contain
identical data. This may not be true for disks copied file by
file using the ISIS Commands.
The attached listing of DCPY is the output of the INTEL
Relocatable assembler. After the program is loaded the disk
to be copied is placed in Drive 0 and a formatted disk which
is to be written on is placed in Drive 1. The program is exe¬
cuted by directing the program counter to COPDK. During
the copy operation the system will indicate to the operator
that each track is copied by a message on the CRT. When the
copy operation is complete the program will return to the
Monitor.
As the program is written it requires a buffer of 6656
bytes beginning at location 6000H. The buffer address may
be changed however in line 7.
A similar program can be written for the INTEL Single
Density DOS. The major difference is the size of the para¬
meter blocks.
Ui Li *T CJ
O © © O
© U. O O
© li. © ©
X X
G I ©
Lu © © n o © o -'j
CO
©**** 111 * 1 X 1
XX X
X >0 ©
© ^ ro © © o >o
*******
1 ****** *
Hl-C
2 U u_
I C ijJ *
O X CO 3
ui co * rv
•<r ui rv ©
© © © ©
© © © ©
<IN C0 0> Ort Cg M^IiI'OMDO'OhNM^K'ONOJ^Oh eg n -T if) -o ©■ CO !>© ’-t Cg
eg IN IN IN n m M rn f'm M ro M ’T W V 'T ^ f f 'TliT y - ) ill ill UI U‘J UI UI UI u~! -0 -o -0
iii * u. eg — ro »
Ui b- -t IN ill -o CD
<E © * * * * *
© © © © © © ©
o © © © © © o
© -m in n %- ui o
© © o © © o o
© © © o © © ©
© © © © o © ©
© O <T © © © O
© -H M © © © >0
rv co ch <r * u *
© © o © © © ©
©©©©©©©
©©©©©©©
T *T
^ ro ui
'T •■T
f -4 © !>
ill eg
* © ©
in ui ©
ui in -o <r
© w ^
© © © ©
o © © ©
© ro •— © © © © © m © © © ©
©©0©0©'0©-f©©0©'0
* i J w Ui u. O H C J M V ill ■<) N CO
—• r g in eg in eg eg eg eg eg
o © © © © © © © © © © © © ©
©©©©oooo©©o©©o
ifj b_ eg <c
cr. © eg eg ©
_i © © © ©
o © © © ©
CC C X h 3
UJ <E U CJ 2
05 Li. X Ui uC
i C Q Ci X
: r 2 2 _j
Ci Cl. CJ O I-
<r x -x - cn
u. CJ Ui X u.
X X
J J J X _J
_j _ 1 _itonjii:-
c -i <r i 1 x <r o iii
uuua_ 1 u u. or
1 eg to v ui •0 N mo- © h eg ro <5- ui
, ^ ^ ^ ^ ^ ti ^ eg eg e g eg eg eg
iUUUUCiUUU
Li © eg rxi ^ i\
eg ro ww ww
o © o © © ©
©coo©©
© © © o © © © © © © © © o
o o © © o o © © © © -o © ©
■c * <1 t-i ii © eg <r h u o "O a co
© ■>-« *- eg eg —1 eg —* eg eg ©• o -r ui
urSMi-iCiM-nCiCiwrtq<TaiiiirJO.
Ot-UuUUhUUOiNUON u u u
^oowoo-ull eg to co * ui u_ © eg ui
n M c <t T *T -T T UI ill ill UI UI UI "O >0 <1
© © © © o © © © © © o © © © © © ©
c © o © © o © © © © © © © © o © ©
© © © © © ©
© © © © © ©
n c h a iii u
© © © © © © ©
co eg eg ui eg eg eg eg
iv ,r; irj n n n eg eg
■o rv <e * u. eg ui co
'O --0 --0 -O -<i fv. f\ !\
O © © O © O© ©
© o o © © © © ©
© © © © © ©
©©©©•© ©
-<.■©© u. rv
© © —* eg eg ©
whhwwOCOOCh
u -»oau©oc©©T-«
a ui h <r n <[ is o c uj u_
rv rv co co co co co co co co co
© © © © © © © © o © ©
© O © © © © © © © © ©
eg ui co * o u. eg r<-j
o-i>ochi>0'©<r
© o© © © © © ©
©©©©©•©©©
Number 30
466
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 41
COMPRESSED SUBROUTINE CALLS FOR SC/MP
Dear Sirs, Received: 78 Aug 24
With reference to your SC/MP subroutine manager in the
March 1977 issue of Dr. Dobbs, please find enclosed a com¬
pressed version of the same.
Yours faithfully, National Semiconductor
Phil Hughes 2900 Semiconductor Dr.
Microprocessor Marketing Manager Santa Clara, CA 95051
7.2.6 Compressed Subroutine Calls.
This example permits the user to impliment nested sub¬
routines while using only 3 bytes per call.
Initialization
LDI
H(HANDL)
; Load address of
XPAH
P3
; Subroutine handler
LDI
L(HANDL)
XPAL
P3
Call
XPPC
P3
.ADDR
SRI
; Address of Subroutine 1
XPPC
P3
.ADDR
SR2
; Address of Subroutine 2
etc.
RETURN:
JMP
RET (P3)
JP
RET (P3)
; Any one of these
JNZ
RET (P3)
JZ
RET (P3)
Organization
Routine
RETURN:
ST
-1(P2)
; Exit Subroutine
LD
@1(P2)
; Get us byte of RET ADDR
XPAL
P3
LD
rai(P2)
XPAH
P3
LD
-3(P2)
; Restore A U
HANDL:
XPPC
P3
ST
@-3(P2)
; Save ALLU
LD
@2(P3)
; Adjust P3
LD
(P3)
; Load lower S/R ADDR
ST
1(P3)
; Save temp
LD
@-l(P3)
; Get upper part
XPAH
P3
ST
2(P3)
LD
(P3)
XPAL
(P3)
LD
@1(P3)
; Restore ACCU
JMP
HANDL
T = MfifODL. .
SAM76-FORTH-STRUBAL
Received: 78 Sept 4
In Volume 3, Number 8 of Doctor Dobbs' Mr. R. D.
Grappel, a co-devisor of STRUBAL criticized “FORTH”
on a variety of points. Since the SAM76 language might be
subjected to virtually identical criticism I find it appropriate
to submit the following in defense of FORTH and SAM76.
Mr. Grappel criticizes FORTH on the basis that the pub¬
lished representations are difficult to read. He by implication
suggests that “pseudo English” is the way to make things
legible; for some people that may be true —particularly if they
use a latin character set. Many people in the world use other
alphabets and linguistic representations, and for them
STRUBAL would be quite foreign, whereas the symbology of
FORTH and SAM76 is readily adaptable to their needs and
desires.
Furthermore it would appear that Mr. Grappel fails to
recognize that FORTH, and SAM76 also, is a “core langauge”
capable of self redefinition to the extreme of looking just
like STRUBAL—or APL—or BASIC —etc. There is a speed
price to pay for such conversion, but that is one way of doc¬
umenting a program for the benefit of the reader—and yet
execute the procedures as written in their highest form.
I am not familiar with the internal details of FORTH,
but I would hope that the FORTH interest group maintains a
registry of well defined resident primitive functions and that
means are provided within FORTH as they are in SAM76
for dynamic change of resident function names to permit
international users to select function names or mnemonics
best suited for their native languages. Portability of programs
on an international basis is thus facilitated without imposing
“anglicisms” on the rest of the world. Note that conversion
of programs by editing is usually not a viable method because
in languages such as SAM76, and probably FORTH, the
function names might not exist until computed at run time,
and consequently the only safe way is to dynamically change
the state of the machine to match the program being run.
Mr. Grappel merely mentions in passing the fact that
STRUBAL requires an overhead of multiple passes and needs
intermediate files. This renders interactivity and immediate
write—test —run mode of operation impractical if not impos¬
sible. Consequently “one shot” programs written in
STRUBAL require considerably more time than those wirtten
in FORTH or SAM76 before the user sees the result sought.
The issue of speed is becoming rapidly a non-issue, and if
one accepts the forecast of infinite speed—zero cost comput¬
ation by the year 1985, then that aspect of STRUBAL be¬
comes totally irrelevant.
Mr. Grappel also glosses over the fact that STRUBAL runs
in a minimum of 16K bytes (possibly 15.7 or 15.8 with
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
467
skilled reprogramming) and that the object code for just the
one particular program is 3.9K bytes as opposed to the 5 to
6K bytes for the FORTH interpreter. I hardly consider it a
saving to have a run time program be 4K bytes versus 5 or
6K bytes if all it can do is one thing. It is even less of a saving
if you need a prior overhead of 16K just to achieve that saving.
Again the issue of space is becoming rapidly a non-issue
and the fact that the run time program is 4K or 6K becomes
totally irrelevant.
It is interesting to note that the number of symbols that
the user has to key in to produce the polynomial illustrated
“5X **2— 7X—10 ” is approximately the same in both
FORTH and SAM76 as illustrated below:
FORTH:POLY DUP DUP * 5 *SWAP 7 * -10-;
SAM76 %dt,POLY, !%su,%su,%mu,5,%mu,X,X,//,
%mu,7,X//,10///
For the purpose of clarity the content of the SAM76 language
text named POLY is analyzed as follows:
%su,%su,%mu,5,%mu,X,X, //,%mu,7,X//, 10/
t X 2 —^ t t 1
Lsx 2 ---1 l_ 7X —I
-5X 2 — 7X-
-5X 2 —7X—10-
Admittedly SAM76 is not primarily intended to be a
scientific or mathematical language, but it is powerful enough
to simulate a substantial portion of APL in about 600 bytes of
user defined procedures. The interpreter requires approx¬
imately 8K bytes of Z80 code and this can be reduced,
without reprogramming, by about 300 bytes at a cost of 75
microseconds per subroutine call (2 megahertz clock system).
It should be noted that the philosophy underlying the
implementation of the SAM76 language required the pro¬
vision of a very rich resident function set —approximately
150—explaining the fact that the interpreter is significantly
larger than required by FORTH.
Cordially, Box257 RRl,
Ancelme Roichel, Pennington, NJ 08534
Descriptions and updates of the SAM76 language may be
found in IEE Computer Society Repository, Dr. Dobbs'
Volume 3, Issue 1, 3, 6 and 8. A good beginner’s tutorial
appears in Creative Computing (May-June) and (Sept-Oct)
1978.
FORTH/STRUBAL REBUTTAL
Greetings: Received: 78 Sept 22
I enjoyed Robert Grappel’s response to my FORTH article.
His language STRUBAL looks like a good piece of work, a
strong candidate to replace BASIC or FORTRAN on small
machines. But I question his comparisons of STRUBAL
and FORTH.
Let’s start where STRUBAL is strongest—clarity and
understandability of programs. I admit that for small programs
like the LIFE example which Mr. Grappel re-wrote,
STRUBAL is clearer than FORTH—to programmers oriented
to BASIC or FORTRAN. But since STRUBAL evidently
isn’t extensible, somebody reading STRUBAL sees the primi¬
tive statements-FOR, NEXT, STRING, PRINT, XTRACT,
etc.—no matter how large the application. In contrast, a large
FORTH program defines an application-oriented vocabulary
—and if it’s documented, the user seldom or never has to look
at the source code of those definitions. A brief description of
what each one does, plus a list of arguments in and results
out, is enough. A STRUBAL programmer always goes back
to the statements of the original language, while a FORTH
programmer can use large or small chunks of previous work,
interchangeably and with no separate subroutine protocols,
linking loaders, or trouble with name conflicts. And FORTH
is structured, with no GOTO and no statement labels in the
system.
Of course any extensible language puts more responsibility
on the application communities to develop reasonable standards
and to avoid useless idiosyncracy. There is more incentive for
communication. Is this a problem, or an opportunity?
Mr. Grappel pointed out that his LIFE program in
STRUBAL took less time to develop than Boulton’s
FORTH version of LIFE which appeared in my article. But
most of Boulton’s time was spent on the word “ARRAY,”
which is a special kind of operation (a “defining word”)
which creates a new data type. Most FORTH systems come
with ARRAY already defined (and now Boulton’s has it too).
STRUBAL also has an array type available, but if a new data
type were needed, it would take some time indeed to define
it (by changing.the compiler).
STRUBAL is a little faster than FORTH when speed
doesn’t count. When it does, critical sections such as inner
loops can be re-written using FORTH’s assembler, to run at
full machine speed. FORTH interfaces so naturally to machine
code that the user doesn’t need to know which operations
are code and which are higher-level; except for speed it’s
transparent. And the higher-level is fast enough that code
is seldom necessary; higher-level FORTH overhead is com¬
monly 30 percent over machine code (on 16-bit stack-type
machines and more like 100 percent on 8-bit micros). FORTH
executes an indirect threaded code which should not be con¬
fused with usual interpreters which are ten or more times
slower than code.
And now for compactness. Indeed it’s true as Mr. Grappel
showed that both systems take about the same space to run
that little LIFE example (1888 bytes for STRUBAL vs.
475 for FORTH, but 3.9K for the STRUBAL run-time
package, and 5 to 6K for the entire FORTH system, which
usually stays in memory at run time). However if you multiply
the size of the project by 50, you get 97K for STRUBAL
vs. 30K for FORTH. And FORTH would probably compare
even better than this, because programming is in increasingly
larger chunks as the application grows, and each invocation of
any chunk (regardless of its size) takes two bytes.
FORTH (like STRUBAL) is supposed to use a floppy,
but recently I played with a stripped-down version which
uses no external storage except an ordinary cassette. This
bare-bones FORTH has no assembler and no editor—it resides
in 3.8K bytes, running stand-alone except for a ROM monitor
which handles reading and writing of the cassette, and I/O
for single characters (which FORTH could do, but it uses the
monitor since it is available). While I wouldn’t want to develop
a major project on this little system, it’s remarkable how
conveniently it does work. You load the cassette (about 20
seconds), then type in and run FORTH source statements.
As soon as each statement is typed, it is ready to run, as it
compiles while being typed. With no disk or editor, if you
make a mistake and don’t discover it until after a carriage
Number 30
468
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 45
return, you have to re-type the whole statement (which is
short, seldom over three lines). FORTH debugging is excep¬
tionally thorough, because the statements are short and mod¬
ular. Without the editor, when bugs are discovered the state¬
ment must be typed over; and worse, on those rare occasions
when a statement way back in the program must be changed,
all later statements which refer to it must also be retyped,
or they will continue to refer to the old definition. This is
why you want a floppy and an editor.
After developing some definitions, you can ‘FORGET’
early scratch work back as far as desired, re-type what is
necessary (e.g. your new utilities, color graphic operations,
or other applications), then save the whole system on a new
cassette. Next time it will take a couple extra seconds to load
the tape, with perhaps a few hundred more bytes, and your
new language is ready. There is no line where the FORTH
system ends and your applications begin—the whole language
(including your programs) is homogeneous.
Later when I do get a floppy for this machine, this little
bit of FORTH will grow into a full professional development
system, just by having three or four pages of FORTH source
code (for an assembler, floppy I/O, and a text editor) typed
in.
Sincerely yours, 1090 Miller Ave.
John S. James. Berkeley, CA 94708
For more information on FORTH, see Forth Dimensions,
the newsletter of the Forth Interest Group, 787 Old County
Rd., San Carlos, CA 94070. Subscriptions are $5. for issues
one through six.
ASTRONOMY APPLICATION FOR PET FORTH
Dear Tom: Received: 78 Sept 11
After reading Robert Grappel’s letter (No. 28, page 28)
comparing FORTH and STRUBAL, I felt that my experience
with FORTH might be of interest to some of your readers.
Although I had been vaguely aware of FORTH for some years,
I had never had the opportunity of trying it out until Pro-
gramma Consultants (3400 Wilshire Blvd., Los Angeles,
CA 90010) made it available for the PET 2001. I’ve had
their PET-FORTH version 1.0 for two weeks now and I find it
to be an ideal language for my needs.
I am currently building microprocessor systems for astro¬
nomical data acquisition and analysis. For this application I
must be able to control custom I/O interfaces and other hard¬
ware. My machines must be physically small and inexpensive,
so large memory and mass storage devices are undesirable.
It must be possible to design code that results in simple and
yet flexible user interfacing. Easy program modification and
testing are essential since much of the program expansion
takes place during (hopefully short) periods of cloudiness
at the telescope. FORTH, with its resident interpreter,
compiler, and assembler, meets my needs perfectly. I can write
a line of code to operate an external device and then immed¬
iately execute that code to see what happens. Since my
debugging involves hardware problems as well as software
problems, separate passes to compile, then execute would be
inconvenient.
Since FORTH code runs at almost full machine speed
(the 100% penalty generally quoted for microprocessors
refers to general FORTH code, not tightly coded inner loops),
I have had no trouble coding clock routines etc. where timing
is important. Several comparisons of FORTH’s speed versus
BASIC’s speed in the PET have yielded ratios of x 9 to x 18
(but BASIC was working to ten decimal digits accuracy,
FORTH only to five digits).
The real advantage of FORTH, however, lies in its essen¬
tial function of defining the vocabulary of a special purpose
dictionary. I can define dictionary entries which carry out the
various basic functions of the telescope and data system.
The user can then use the FORTH machine as a programmable
calculator with the equivalent of many special function com¬
mands. As an example, the following code might point the
telescope at a specific position (right ascention -RA- and
declination -DEC-), select a blue filter, take data for 10
seconds, and record that data.
12 33 26 RA= -21 33 06 DEC = POINT
BLUE FILTER 10 SECS TAKE DUP DAT A = RECORD
In this example I use previous FORTH definitions to store
the coordinates, activate the telescope positioning motors,
push the filter number of the BLUE Filter on the stack, output
that filter number, set up a data integration time, digitize the
data, store it at the next location in the array DATA, and
finally output it to the recorder. Although the definitions of
these functions might not be “readable,” I think most would
agree that the final code used by the observer is very readable.
For my purposes definition readability is much less important
than this ability to define a logical and simple vocabulary for
the user. Even the best observer tends to become a bit mud¬
dled at 3 AM on a cold, partly cloudy night and I want to give
him as much help as possible. Although STRUBAL or other
languages could have been used to program a series of prompts
(“RA?”, “DEC?”, “FILTER?”), this would “lock in” the
exact sequence of operations. FORTH gives me the flexibility
to set up a variety of operations, repeat them, and change
them as I choose.
I don’t think it is necessary to comment at any length on
specific points of Mr. Grappel’s letter, but I would like to
make the following points:
1. His first example of the difficulty of reading FORTH
(the POLY definition) essentially comes down to the old
argument of postfix versus infix operators. Some like one
(and buy HP calculators), some like the other (and buy
TI calculators).
2. The comparison of a 3.9K run-time STRUBAL package
with the full 5 — 6KFORTH package is unfair. Using the
cross-compile option of FORTH would result in a run¬
time FORTH package of less than IK bytes for this pro¬
gram.
3. I doubt that STRUBAL would run “much faster” than
FORTH since optimum machine language code could only
run twice as fast as FORTH.
To close, STRUBAL looks like an excellent choice for the
BASIC programmer who wants to move up to a compiled
language, but for me FORTH looks much more useful.
Sincerely, Department of Physics & Astronomy
John P. Oliver University of Florida
Associate Professor of Astronomy. Gainesville, Florida 32611
Page 46
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Number 30
469
QUESTIONS - AND ANSWERS - ON DATA
TRANSFER
Dear Mr. Pugh: Received: 78 Aug 21
First let me say how much I appreciated your article in
Dr. Dobb’s Journal, No. 26. Your article provided a great
deal of information in a field in which I am just now getting
started. Toward this end, I have subscribed to the PCNET
Committee publications recently. I also plan to start attending
their meetings in this area.
Right now I am putting together a disc system using a
Tarbell board and a couple of drives. As soon as I have this
system operating, I plan to obtain your program from the
CP/M User’s Group.
All the above gives some background for the questions I
am about to ask: What is the reason for having to operate
the system at a baud rate half of that of the terminal console?
How can this limitation be overcome? I would like to operate
at a baud rate at least of 300.
In connection with your discussion of losing data during
file transfers, I anticipate even more trouble than you have had
because from the documentation I have, my head will unload
after only 2 revolutions (I am using Shugart 800 drives). I do
not know yet how I will solve this difficulty.
Very truly yours, 1096 W. Remington Dr.
Robert L. Edens Sunnyvale, Calif. 94087
Dear Mr. Edens:
I am glad to see you plan to join the PCNET as I believe
the more participation it receives the more effective it will
become.
As to the questions you raised in your letter, I am afraid
I did a very superficial job in explaining system timing. The
following discussion may be helpful in clarifying this.
1. If communication is taking place between two personal
computers with each operating at 300 Baud (Modem rate)
and each transmitting via the keyboard, there should be
no data lost even if a 110 Baud terminal is being used as
console device for one of the computers. This is so because
it is only the character burst rate that occurs at 300 Baud.
In order to cause the true data rate to be 300 Baud, the
operator with the fast console device would have to type
at a rate of 300 words per minute—where a word consists
of 5 letters and a space on average.
2. If a large time sharing computer is communicating with a
personal computer at 300 Baud and the console device of
the personal computer (PC) uses a 300 Baud printing
terminal as console, some data will probably be lost. This
is because the TSC outputs a line at a time and usually
transfers it at the maximum rate allowed by its modem
device. At the PC end of the communications, some delay
is inserted between the receipt of data by the computer
and the relay of this data-on a character by character
basis—to the console device. This is caused by the time
taken to execute the instructions necessary to input/output
the data and, perhaps more time consuming, check the
status of each I/O device (the modem and console respect¬
ively) to see if they are ready for a data transfer. This time
delay builds up with each character transmitted if the con¬
sole is only capable of 300 Baud operation. If the data
string is sufficiently long, data loss will occur. If the console
device were capable of transfering data at 600 Baud then
both the computer and the console would be “twiddling
their thumbs” while waiting for receipt of the next charac¬
ter.
Perhaps this answers the question as to why the system
(modem) must operate at a baud rate half that of the
terminal console. Of course there is no problem if the
console is operating at a baud rate significantly higher
than the modem rate, e.g., modem.rate=300 Baud; console.
rate=9600 Baud. Further, choosing a ratio of 2 to 1 is
really an oversimplification. The real value is somewhere
between 1 to 1 and 2 to 1.1 can only say that my printing
terminal successfully copied data at a rate of 150 Baud
while it was operating at 300 Baud. However, it would
not copy data reliably if its rate were set equal to the data
rate.
As to the question of data loss during file transfer. No
data loss will occur when your PC is transmitting files
since it does so “in its own good time.” However, when
you are receiving a file, it is the guy at the other end who
determines the rate, i.e., whether the data is passed through
the modem at its maximum rate or whether there is a
certain amount of “dead time” between characters or
groups of characters. The following approaches can be used
to overcome this problem:
3. At 300 Baud each character requires a minimum of 30.3
msec time, i.e., (30.3 msec/Character ==> (30.3 sec)/(lK
characters). Thus, it takes approximately 1 minute to trans¬
fer 2K characters. If, instead of writing each block of
128 characters out to disk as soon as the data block is
accumulated, one were to buffer (save) the data in memory,
one could buffer 15 minutes of data with 30K of memory.
The data could then be recorded on disk. Thus, by breaking
up the data to be transferred into manageable “time slices”
one could transfer a large file without data loss.
4. If communication is occuring between computers which
adhere to the PCNET protocol (or some similar protocol)
then a file can be received without data loss. As in (3)
above, memory buffering in excess of 128 characters (bytes)
is required. However, the amount of buffered data is small
compared to the above approach. Under the PCNET
protocol, data is transmitted in block format with the data
content of each block being 0-253 bytes. To keep things
simple, assume block size=256 bytes. The receipt of each
block must be acknowledged although up to four blocks
may be transferred before receipt of the first block is
acknowledged. If no acknowledgement (ACK) is sent,
the sender goes idle and awaits ACK before transferring
more data. Thus, a data buffer of IK BYTES (4*256
BYTES) is sufficient to assure no data loss. The data thus
buffered can be written to disk before the sender “times
out” and breaks off communications. Following the trans¬
fer of data to disk, the ACK for each of the four data
blocks can be sent to the sender resulting in the restart
of data transmission of the remaining data, etc.
5. If one is communicating with a TSC which does not
provide for PCNET protocol and one can not afford to set
aside a large buffer as in (3) above, then he may achieve
the desired result by using interrupt processing and double
Number 30
470
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 47
buffering. Thus if one had an IMSAI PIC-8 board or simi¬
lar interrupt handling board and a DMA floppy disk con¬
troller he could force an interrupt each time data was avail¬
able from the modem and store it in one of the two buffers
allocated for data storage. When the first buffer became
full the incoming data would be stored in the second buffer
while the contents of the first buffer were written to
disk. Each buffer could have a size equal to one physical
disk record (128 bytes). Thus, only 256 bytes of memory
is needed to implement double buffering.
It may be possible to perform interrupt processing without
a DMA controller for the floppy disk but I have not yet
figured out how to do it. Consider that whereas it takes only
4.1 msec to transfer one physical record (128 Bytes) to
disk—assuming a 250K bit data transfer rate; the total time
required may be much longer. This is because the time be-
ween blocks is sufficiently long to assure that the head has
“unloaded.” Thus, it takes 35 msec to load the head and an
average of 83 msec to reach the desired sector—one revolu¬
tion of the disk takes 166.6 msec. Thus, 118 msec may be
required before writing can begin. Since the microprocessor
must be ready to control the writing of each data byte, it must
wait for the instant that the sector has been reached and
immediately begin data transfer. This assumes that the read/
write head is already positioned at the proper track. Since at
300 Baud each character takes 30.3 msec one will “drop”
3 to 4 characters on average while attempting to write a
record to disk.
Sincerely, 9655-M Homestead Court
Tim J. Pugh, Jr. Laurel, Md. 20810
Phone:(301) 776-5253
LAST CHANCE ON DG TV READOUT CARD
Dear Dr. Dobbs: Received: 78 Sept 13
It has come to my attention that The Digital Group has
discontinued production of Dr. Suding’s 16 by 32 TV Read¬
out Card. They still have on hand approximately fifty printed
circuit cards which they are selling for $15.00 a piece.
This video card has some very nice features: parallel inter¬
face to the computer for fast update, on board memory,
use of the Motorola MCM 6571 pre-programmed character
generator (there are ten different ones to choose from) and
the card connects easily to a television set via an RF mod¬
ulator (Pixe-Verter #PXV-2A) and a 72 ohm to 300 ohm
transformer (Radio Shack). I use a wire-wrapped version
which is connected to a 12 inch Sony and I get an excellent
picture. If you decide to purchase the card be sure to get the
5.990 MHz crystal at $4.95 and the schematic and circuit
description DOC TVC-1-R1 for $1.50. Altogether you
shouldn’t have to spend over $80.00 for the card and parts,
not counting the RF modulator and the 72 ohm to 300 ohm
transformer. A good buy, considering you also get the printed
circuitry for the Suding 1100 Baud Casette Interface on the
same card. I would recommend a couple of modifications.
Capacitors Cl, C2, C3 and C4 should be changed from Mylar
to Mica. My board works better without capacitor C4. If you
wish to use the white rectangle for a cursor rather than the
underline, the least significant data line must be inverted by
inserting a 7400 NAND gate between pin connector 8 and
IC 22. IC 22 must be changed from a 7430 to 74H30. This
makes the card home up on octal 376 and frees the white
rectangle for use as a cursor.
The enclosed program is a general keyboard input program
with video echo and utilizes a software-controlled cursor.
If you do not invert the LSB, byte 075 must be changed from
177 to 137 and byte 174 from 376 to 377. The various sub¬
routines contained within the program are screen clear with
cursor at home-up position, back space, carriage return,
up one line and down one line. If you use a status bit with
your keyboard, a call to your own input routine should be
inserted at 011.
Sincerely, 12012 Pebblebrook Lane
Don Woods. Carmel, Indiana 46032
P.S.
1. There are two obvious errors in the schematic. Line 4 of
IC 29 and line 4 of IC 9 do not connect to the five plus line.
Oddly enough the same mistake appears in the schematic
for DG’s 1024 Character TV Readout, IC 13 and IC 3.
2. Prime parts can be obtained from Jameco Electronics.
Good prices and fast service except for their 22/44 printed
circuit edge card connector. Stick with Vector, Cinch or
TEKA.
000
061
111
hhh
LX I SP
SET STACK
003
315
152
100
CALL
CALL CLRSC
006
315
140
100
CALL
CALL TVDSP1
Oil
000
NOP
012
333
004
IN
KYBRD
IN PORT 4*
014
346
177
AN I
MSB EQU 0
016
303
362
100
JMP
JIMP TO KYBRD PATCH
021
376
015
CPI
COMPARE RETIRN KEY
023
314
217
100
cz
CALL CRLF
026
376
137
CPI
COMPARE BACK SPACE KEY
030
314
241
100
cz
CALL BKSP
033
376
012
CPI
COMPARE LINE FEED KEY
035
314
152
100
cz
CALL CLRSC
040
376
025
CPI
COMPARE CONTROL U
042
314
271
100
cz
CALL IP
045
376
004
CPI
COMPARE CONTROL D
047
314
303
100
cz
CALL DWN
052
376
000
CPI
OTHER DATA THAN CONTROL ?
054
304
140
100
CNZ
CALL TVDSP1
057
303
Oil
100
JMP
JMP BACK TO KYBRD
062
076
040
MV I A
LOAD A WITH BLANK
064
366
200
OR I
TVNC
SET MSB HIGH
066
323
003
OIT
OUT PORT 3*
070
257
XRA A
CLEAR A
071
323
003
OUT
TIRN OFF STROBE*
073
311
RET
RETIRN
074
076
177
MV I A
LOAD A WITH WHT RECTANGLE
076
315
064
100
CALL
CALL TVNC
101
311
RET
RETIRN
102
257
XRA A
TRIGR
CLEAR A
103
107
MOV B,A
CLEAR B
104
074
INR A
LSB EQU 1
105
315
066
100
CALL
CALL TVNC PL IB 2
110
005
DCR B
DECRE?.£NT B
111
302
104
100
JNZ
JIMP BACK IF NOT DONE
114
005
DCR B
DECREMENT B
115
074
INR A
LSB EQU 1
116
315
066
100
CALL
CALL TVNC PLUS 2
122
005
DCR B
DECREJENT B
123
302
115
100
JNZ
JllJP BACK IF NOT DONE
125
311
RET
RETIRN
126
315
102
100
CALL
CIRSR
CALL TRIGR
131
315
074
100
CALL
CALL WHT RECTANGLE
134
315
102
100
CALL
CALL TRIOR
137
311
RET
RETIRN
140
315
176
100
CALL
TVDSP1
CALL TVDSP2
143
315
062
100
CALL
CALL BLANK OIT
146
315
126
100
CALL
CALL CIRSR
151
311
RET
RET
152
001
002
000
LX I B
CLRSC
LOAD BC WITH COINT
155
315
062
100 4 *
, CALL
CALL BLANK OUT
160
005
DCR B
decrement b
161
302
155
100
JNZ
JllIP BACK IF NOT DONE
164
015
DCR C
DECREMENT C
Page 48
Dr. Dobb's Journal of Computer Calisthenics 81 Orthodontia, Box E, Menlo Park, CA 94025
Number 30
471
100
165
302
155
100
JNZ
JIMP BACK IF NOT DONE
170
076
040
MV I A
LOAD A WITH CRLF COINT
172
127
M0VD ,A
SAVE COINT
173
076
376
MV I A
LOAD A WITH HOME BYTE
175
311
RET
RETURN
176
366
200
OR I
TVDSP2
SET MSB HIGH
200
323
003
OUT
OUT PORT 3*
202
257
XRA A
CLEAR A
203
323
003
OUT
TERN OFF STROBE*
205
315
212
100
CALL
CALL CNTCHK
210
025
DCR D
DECREMENT COINT
211
311
RET
RETURN
212
272
CMP D
CNTCHK
COMPARE COINT
213
300
RNZ
RETIRN IF NOT ZERO
214
026
040
MV I D
LOAD D WITH COINT
216
311
RET
RETIRN
217
315
062
100
CALL
CRLF
CALL BLANK OUT
222
000
NOP
223
074
njR a
LSB EQU 1
224
315
066
100
CALL
CALL TVNC PLUS 2
227
025
DCR D
DECREMENT COINT
230
302
223
100
JNZ
JIMP BACK IF NOT DONE
233
026
037
MV I D
LOAD D WITH COINT
235
315
143
100
CALL
CALL TVDSP1 PLUS 1
240
311
RET
RETIRN
241
315
062
100
CALL
BKSP
CALL BLANK OUT
244
315
102
100
CALL
CALL TRIGR
247
315
126
100
CALL
CALL CIRSR
252
024
3NR D
INCREMLNT COINT
253
076
041
MV I A
LOAD A WITH D CNT PL IB 1
255
272
CMP D
COMPARE A WITH D
256
302
264
100
JNZ
JIMP IF SAME
261
076
001
MV I A
LOAD A WITH 1
263
127
MOV D,A
SET D COINT TO 1
264
257
XRA A
CLEAR A
265
311
RET
RETURN
266
000
NOP
267
000
MOP
270
000
NOP
271
315
062
100
CALL
IP
CALL BLANK OUT
274
315
315
100
CALL
CALL IP 32
277
315
126
100
CALL
CALL CIRSR
302
311
RET
RETURN
303
315
062
100
CALL
DWN
CALL BLANK OUT
306
315
344
100
CALL
CALL DWN 32
311
315
126
100
CALL
CALL CIRSR
314
311
RET
RETURN
315
325
PUSH D
IP 32
SAVE COINT
316
257
XRA A
CLEAR A
317
001
340
000
LX I B
LOAD BC WITH COINT
322
074
INR A
LSB EQU 1
323
315
066
100
CALL
CALL TVNC PLUS 2
326
005
DCR B
DECREMENT B
327
302
322
100
JNZ
JIMP BACK IF NOT DONE
332
074
INR A
LSB EQU 1
333
315
066
100
CALL
CALL TVNC PLUS 2
336
015
DCR C
DECREMENT C
337
302
332
100
JNZ
JIMP BACK IF NOT DONE
342
321
POP D
RESTORE COINT
343
311
RET
RETIRN
344
325
PUSH D
DWN i2
SAVE COINT
345
257
XRA A
CLEAR A
346
006
040
MV I B
LOAD B WITH COINT
350
074
INR A
LSB EQU 1
351
315
066
100
CALL
CALL TVNC PL IB 2
354
005
DCR B
DECREMENT B
355
302
350
100
JNZ
JIMP BACK IF NOT DCNE
360
321
POP D
RESTORE COUNT
361
311
RET
RETURN
362
376
033
CPI
PATCH
COMPARE
364
312
XXX
XXX
JZ
JIMP TO MONITER
367
303
021
100
JMP
JIMP BACK TO KYBRD
372
000
NOP
373
000
NOP
374
000
NOP
376-
000
NOP
377
000
NOP
*MIET BE CHANGED TO CONFORM TO USERS CWN PORTS
LEDIP AVAILABILITY
the published version (Version K4). The reduction in code was
achieved by deleting the LINE REPLACE/AD JUST routines
and using the LINE DELETE and LINE INSERT routines to
achieve the same result. The penalty for this code reduction is
a loss in speed which becomes apparent when editing large
amounts of text. Apart from this difference, the two versions
are completely compatible. In fact, the LEDIP user need not
be aware of this difference.
Version K6 source listing is available for $4.50. LEDIP
manual with sample runs and hex dump is available for $3.00.
LEDIP hex paper tape or KIM hypertape cassette (on user’s
cassette) is available for $2.50. The 6502 Program Exchange,
2920 Moana, Reno, NV 89509 can be contacted for more
information. Thanks.
Sincerely yours,
Kiumi Akingbehin Wayne State University
Computer Science Department Detroit, Michigan 48202
SUMMER 1979 COMPUTER SCIENCE
SPECTACULAR
Received: 78 Sept 14
The Summer 1979 Institute in Computer Science at the
University of California, Santa Cruz, U.S.A., will feature two
major programs—an advanced course on Computing Systems
Reliability to be offered July 9-20, and a symposium on
Programming Methodology to be held in August.
Programming Methodology features 25 of the world’s
leading figures in computer science including Edsger W.
Dijkstra, Burroughs Corporation, The Netherlands; David
Gries, Cornell University, U.S.A.; Donald Knuth, Stanford
University, U.S.A.; C.A.R. Hoare, Oxford University, England;
O.J. Dahl, University of Oslo, Norway; J.J. Horning, Xerox
PARC, U.S.A.; Niklaus Wirth, Institut fur Informatik, ETH,
Zurich, Switzerland; W. M. Turski, Warsaw University, Poland;
and William McKeeman, University of California, Santa Cruz.
The symposium is three weeks in length. Participants may
attend one, two or three weeks of the program.
Computing Systems Reliability will be presented by Brian
Randell, University of Newcastle upon Tyne, England, and a
dozen renowned lecturers.
For information, write to Institute in Computer Science,
University of California Extension, Santa Cruz, California,
U.S.A. 95064.
Dear Tom: Received: 78 Sept 6
Your readers might be interested in the following additional
information regarding LEDIP, the KIM/6502 text editor.
Version K6 of LEDIP is available from The 6502 Program
Exchange. Version K6 occupies less memory (116 bytes) than
COMPUTERS IN THE HUMANITIES
Received: 78 Sept 10
The Fourth International Conference on Computing in
the Humanities will meet August 19-22, 1979, at Dartmouth
Number 30
472
Dr. Dobb's Journal of Computer Calisthenics & Orthodontia, Box E, Menlo Park, CA 94025
Page 49
College. Papers on any topic involving computing in the
humanities will be considered for presentation. Languages of
the conference will be English, German, and French. AB¬
STRACTS of 500 to 1000 words should be submitted by
December 1, 1978; acceptances will be announced by April
1, 1979. For further information, contact Stephen V. F.
Waite, Chairman, ICCH/4, Kiewit Computation Center, Dart¬
mouth College, Hanover, New Hampshire 03755.
BAY AREA
A users group for Heath owners will be starting in the San
Francisco Bay Area. Contact Bob Bance, 218 Roble Ave.,
Redwood City, CA 94061.
Z USERS GROUP FORMED
The formation of a Users Group for users of the Z-8, Z-80,
Z-8000, Mostek 3880, and other microprocessors in the same
family, to be called the “Z Users Group,” was announced by
Jon D. Roland, its organizer.
Roland called for contributions to the newsletter that the Z
Users Group will publish, including systems and applications
software, interfacing problems and solutions, evaluations,
extensions, and modifications to products based on these
chips, criteria for selecting chips for various applications,
proposed Z-8000 bus standards, benchmark programs, ideas
for features in future chips in this family, and information on
new products, suppliers, software available, and interesting
applications. The Z Users Group will be independent of Zilog,
Inc., Mostek, or any other producer or user of Z-chips.
One project Roland hopes to get support for is a group
purchase of Z-8000 chips, so that members can get some
of the first chips at reasonable prices for evaluation and devel¬
opment. The address of the Z Users Group is 1015 Navarro,
San Antonio, Texas 78205. (512)222-1427. The dues are
$5.00 per year.
CLEVELAND DIGITAL GROUP
Received: 78 Sept 1
The Cleveland Digital Group meets the third Sunday of
every month at 2 p.m. The CDG clubhouse is located 100
feet east of Broadway Ave. at 8700 Harvard Ave., Cleveland,
Ohio 44105.
TRACE
The Toronto Region Association of Computer Enthu¬
siasts, Box 545, Streetsville, Ontario L5M 20 Canada,
are assembling a list of certain of their members who are
willing to assist other members with hardware and software
questions in exchange for whatever the two parties can agree
on. Their newsletter, TRACE also contains a helpful question
and answer column.
PAPER STRIKE HITS HOME
Due to a long-term strike in the paper industry which
has been going on since Spring, we have not been able to
obtain our usual quality of paper and are forced to print
this issue of Dr. Dobb’s on lower quality paper. It is very
embarrassing to have to raise the price of the magazine and
then not be able to maintain the physical quality due to
an industry-wide shortage. We understand that there are
good prospects for a settlement soon, but that does not
mean an immediate end to shortages. We will, of course,
go back to our regular paper as soon as humanly possible,
but in the meantime we must ask our readers to bear with
us. —Tom Williams
Page 50
Dr. Dobb’s Journal of Computer Calisthenics & Orthodontia. Box E, Menlo Park, CA 94025
Number 30
473
Index
This is an index to articles and programs, but some letters have also been indexed. References are of the form
issue number/page numbers. Those in normal type are references to programs. References separated by a
comma are connected in some way; those separated by a semicolon are completely distinct. Unless otherwise
marked, a program is in assembly language. Except for author entries the processor type is marked or clear from
the context. In general, a program can be found by author, processor type, and program type.
The following table gives the correspondence between month/year and issue numbers.
Vol 1 - 1976 Vol2- 1977 Vol 3 — 1978
January
1
11
21
February
2
12
22
March
3
13
23
April
4
14
24
May
5
15
25
June/July
6
16
26
August
7
17
27
September
8
18
28
October
9
19
29
November/December
10
20
30
1802. see COSMAC
6502
arithmetic
floating-point 7/17-19, errata 10/57
trig functions (extensions to KIMATH) 20/15-21
article
programming tricks 28/29
cassette interface 27/31 -33
disassembler 8/22-25
(BASIC) 21/6,errata 23/3, 27/39
games
lunar lander 7/22-25
mastermind 8/26-27
text editor 29/4-12
utilities
breakpoint routine 3/17-19, errata 8/33
debugger 19/42-44
memory test 17/23; 21/4-5
monitor 7/20-21
opcode decoder 17/20-22, 19/42-44; 22/5-7
relocator 14/30-31
string output 8/33, 10/50, 12/8
see also Apple-ll; KIM-1; BASIC, tiny: Pittman 6502
6800
articles
LISP 28/24-25
SWTPC I/O control interface 17/35-37
Resident Assembler 8/19-21
programming tricks 6/19-10; 29/3
disassembler 13/30-33
8080 emulator 28/4-18
GPM (macroprocessor) 20/22-29
graphics 16/19-20
interface to IEEE 488 bus 16/31 -55
utilities
display test 26/30
memory clear 29/43
memory test 5/9; 25/28-33
timer routines 9/21
see also SWTPC; BASIC, tiny: Pittman 6800
8080
arithmetic
multi-precision 13/15-23
expression evaluator 29/34-40
articles
BASEX (language) 30/26-31 +
8080 emulator (on 6800) 28/4-18
Intel - NEC chip differences 10/14-15
programming tricks 6/9-10; 28/29 ; 29/3
disassembler 12/30-43, 17/15 ; 21 /38-46; 27/4-18
(BASIC) 13/25-29
games
button button 6/38-39
chase (a dot) 10/58-59
life 10/60; 24/10-11
oops (line drawing) 9/30
unizap (teaser) 5/10-11
see also games: chase (by robots)
graphics, see graphics: 8080
languages
ACT (macroprocessor) 24/27-46, (PL/M) 23/20-45
BASIC, see BASIC
CASUAL 10/19-32, 12 / 4 , 12 / 44-45
KAPIAR (macroprocessor) 20/31 -59, errata 23/3
LISP 30/4-11
MINOL 4/9-17 errata 6/36, 7/32
PILOT, see PILOT: 8080
miscellaneous 4/5;8/12;8/18
music program 2/6-7, 3/6, 8/32-33,16/21
operating system
Kernel 18/20-40
text editor 6/13-26
utilities
backspace routine for display 19/18
binary tree routines 30/15-17
bootstrap 6/8
compactor (for BASIC programs) 9/31
debugger 9/26-29
diskette copier (ISIS) 30/40-41
disk file dumper (Northstar) 28/38-41
drivers
disk 12/12-17
display 2/34; 30/48-49
modem 26/4-16
loader 3/16, 7/31
memory
clear 8/32-33
dump 26/18-23;27/4-18; (vocal) 28/42-46
test 8/32-33
monitor 4/18-32
reformator (for assembler programs) 6/10
relocator 13/8-9,22/14-20
sort (quicksort) 24/20
status push/pop routines 29/3
word processor 29/18-29
see also H-8; Microsoft; Mits; Polymorphics;
Processor Technology; SOL
8086
description of 27/19-21
Abshire, Jim 10/52-53
accounting program (BASIC) 19/36-41
acoustic coupler, see modem
ACT (macroprocessor) (PL/M) 23/20-45, (8080) 24/27-46
Agoston, Max K. 18/20-40
Akingbehin, Kiumi 29/4-12
Alevy, Gary 12/28-29
Alexander, Mark 10/34-50
Allen, Dave 16/7
Allison, Dennis 1/1-12;2/4-5; 13/34-35; 29/13-15
Anderson, James 29/30-33
Anderson, Ken 25/17-20
APL. see also EMPL
APL Core Project 17/18-19
Apple-II (6502)
utilities for BASIC
renumber 23/4-9
append 23/4-9
erased program recoverer 26/31-33
see also 6502, KIM-1
arithmetic
binary calculator (KIM-1) 23/13-15
expression evaluator (8080) 29/34-40 (BASIC) 6/11-12;
10/52-53
floating-point (6502) 7/17-19, errata 10/57
miscellaneous functions (BASIC) 29/13-15
multi-presicision (8080) 13/15-23
square root routine (algorithm) 13/23
trig functions (extension to KIMATH) (6502) 20/15-21
see also number systems: conversions
Armstrong, Arthur 19/28-29
Arnold, John 1/13-17, 2/13-31
Arnold, Mark 2/8-12
Assembler, 6800 Resident
article on 8/19-21
Barber, Jerry 11/8-62
barcodes 14/36-43
BASEX (language) 30/26-31 +
BASIC
criticisms of 2/4-5;30/18+
games in. see games
LLL (Lawrence Livermore Labs) (8080) 11/8-62
miscellaneous functions (BASIC) 29/13-15
tiny
design and history 1/1-12
Denver (F.J. Greeb) (8080) 3/20-30, errata 8/34
Palo Alto (Lichen Wang) (8080) 5/12-15, 6/35
extensions 12/6-17; 15/6; 19/18; 26/34-141; 29/3
Pittman 6502
extensions 30/32-33
Pittman 6800
extensions 9/23; 12/5; 12/7
Texas (Whipple/Arnold) (8080) 1/14-17; 2/13-31
extensions 2/34; 6/34; 8/30-31
see also CASUAL; FOCAL; MINOL; NIBL; SCELBAL
and under manufacturer's names '
Baum, Allen 8/22-25
Baunach, S.C. 16/31 -55
benchmarks (BASIC) 15/8
binary tree routines (8080) 30/15-17
black box, computer as 14/34-35
Boaz, Ray 5/9
book reviews: 9/36; 11/15; 11/62; 14/46
bootstrap (8080) 6/8
Borgerson, Mark J. 7/29-30
Boute, R.T. 22/46
Bowles, Kenneth L. 23/16-19
Bradshaw, Jack 7/20-21
breakpoint routine (6502) 3/1 7-19, errata 8/33
(KIM-1) 16/25-27
Bridge, Theodore E. 20/12-13; 26/24-27; 30/12-14
Britton, Keith 30/34-39
Broom, J. 7/8-9
Broucke, R. 16/12+; 16/13-14 ;16/1 7-19
Buchanan, Martin 9/32-35, 10/54-55, 13/37
bus
IEEE 488 16/31-55
S -100 7/8-9 ; 25/40-46
STD 30/34-39
business software
accounting program (BASIC) 19/36-41
calculator, see arithmetic
calculator chip, interface to micro 1/18, errata 7/16
cassette
interface, modem as 10/7, 14/6-7, 19/5
interface (6502) 27/31-33
I/O (6502) 26124-27,29-41
CASUAL (8080) 10/19-32, 12/4, 12/44 -45
Cecil, Alex 23/20-45, 24/27-46
CHAOS (operating system) 26/3, 27/3
Chapman, David 30/18+
Christensen, Ward 12/30-43
Cline. Arthur W. 23/11 -12
Coats, Jack O. 3/16
475
codes & cyphers 7/12- 15. 8/35-36; 9/16-18; 12/9-10;
(BASIC) 15/9
Cohen, Harvey A. 13/12-13; 24/10-11
Comer, Edward I. 12/11
compactor (for BASIC programs) (8080) 9/31
compiling, article on 25/4-16
computer control of tape deck 8/3-6
computer crime bill 28/36-37
COSMAC (1802)
article on 15/34-44
utilities
I/O, monitor, music, timer 19/30-35
CPI 600 11/3+
CP/M (operating system) 4/5
CRT. see display
curve-fitting routine (FOCAL) 30/12-14
Dahl, Aubrey 28/20-23
Data-Boy™ (speech digitizer) 29/30-33
data communication, see networks
Dazzler, TV. see graphics: 8080: dazzler
DEAFNET 17/10
debugger
for 6502 19/42-44
for 8080 9/26-29
for Z-80 24/12-18
delivery delays, report on 19/6-9
Denney,D. 7/8-9
Dickenson, John 11/8-62
Digicast Tl ^ Protect 29/16-17
Dinely, M.G. 13/15-23
disassembler
for 6502 8/22-25; (BASIC) 21/6, errata 23/3, 27/39
for 6800 13/30-33
for 8080 1 2/30-43, 17/15; 21/38-46; 27/4-18
(BASIC) 13/25-29
for Z-80 (BASIC) 26/42-44
disk, floppy
diskette copier (8080/ISIS) 30/40-41
file dump (8080/Northstar) 28/38-41
interface and driver (8080) 12/12-17
displays
plans for display board 6/30-33
ideas for 6/28; 10/8; 12/4; 15/17; 16/11
utilities
backspacer (8080)19/18
driver (8080) 2/34; 30/48-49
tester (6800) 26/30
Dompier, Steve 2/6-7
Eaton, John 20/15-21; 23/13-15
Eckard, Royce 11/8-62
EDITHA (machine-code editor) (6502) 25/34-39
editor, machine-code 25/34-39
editor, text, see text editor
Elizondo, Ed 27/41
Elliott, Dan 12/24
Emerson, Richard B. 19/15-17; 26/18-23; 27/27-30
EMPL 14/12-16; 16/11
emulator (of 8080 on 6800) 28/4-18
Espinosa, Chris 8/33
expression evaluator, see arithmetic
F8
FD8 disk system, modifications to 18/44
Ferguson, Mickey E. 12/7
Finkel, LeRoy 7/36-37
Fisher, Eugene R. 9/26-29; 11 /8-62; 12/12-17
floating-point, see arithmetic
FOCAL (FCL65E version) 30/12-14
Formaniak, Peter G. 13/10-11
FORTH 25/21-27; 28/26-27; 28/28, 30/44-46
French, Gordon 22/22-39
Fullmer, Howard 25/40-46
Fylstra, David Jon 17/10
Gabrielson, Mike 24/20; 27/19-21; 29/34-40; 30/15-17
games
acey-ducey (BASIC) 7/26-27
button button (8080) 6/38-39
chase
(a dot) (8080) 10/58-59
(by robots) for (8080/VDM) 15/10-17
errata 19/20
modifications
impatient robots 16/30
real time 17/26
to Poly VTI 17/27-29
proper credit 18/41
rewrite for (8080/Dazzler) 22/30-41
life
(BASIC) 1/13; 16/12+
(8080) 10/60; 24/10-11
(FORTH) 25/24
(STRUBAL) 28/28
further references 17/24
lunar lander (6502) 7/22-25
mastermind (6502) 8/26-27
number guess (STRUBAL) 23/10
oops (8080) 9/30
slots (BASIC) 7/26-27
stars (BASIC) 7/26-27
teaser (brain teaser, unizap, shooting stars)
(8080) 5/10-11; (BASIC) 7/29-30; 12/11
tiny trek (MINOL) 6/37, errata 7/31
trap (BASIC) 7/26-27
zapp the moon man (CASUAL) 10/24; (BASIC) 12/24
Garetz, Mark 7/22-25
Gaugler, Gary 28/4-18
Gerhold, George 27/46-47
Gordon, H.T. 12/8; 17/20-22, 19/42-44; 22/5-7; 25/34-39;
28/29
GPM (macroprocessor) (8080) 20/22-29
graphics
6502
GT6144 14/32; 30/32-33
6800
oscilloscope 16/19-20
8080
dazzler 19/21 -27; 22/22-29; 22/30-41
P.T. VDM 8/28-29; 16/28-30; 18/8-19
Poly VTI 13/12-13; 19/28-29; (BASIC) 16/17-19
hardware 20/6-8; 26/41
Graves, Rod 13/41-44
Greeb, F.J. 3/20-30; 6/13-26
Greenlaw, Richard 27/4-18
Gruhn, David 12/9-10
H-8
bad review 19/10-13, retraction 21/3, parody 21/5
reviews 20/9-11; 30/22-25
Hahn. Harvey E. 3/15
Hancock. Les 24/12-18; 27/22-26
handicapped 16/4; 17/10; 18/7
Happy Lady 1/5-10
hardware
new
8080 floppy disk interface 12/12-17
6502 programmable 1C tester 28/33-35
hardware, new (cont.)
homebrew TV display board 6/30-33
modifications
H-9, lower case 28/30-32
I MSA I
RAM-4A fix 3/6, 13/7
memory clobberer fix: 8/17; 16/60
VDM-1, fix 17/33-34
TVT-11
64 char/line & scrolling 12/25-27,
proper credit 15/45,
errata 16/56,
extension 22/46
64 char/line 12/28-29
lowercase 16/57
bell 26/47
proposed
segmented memory 12/11
extended addressing 14/35
Hayden, Russ 12/6-7
Heath kit. see H-8
Hertzfeld, Andy 26/31-33
hexadecimal (or hex), see number systems
HI, tiny 9/32-35. 10/54-55, 13/37
Hicks, Bruce 16/21
Hudson, David 16/19-20
humor 8/17, 10/32; 14/44; 22/3
Hutchinson, Perry C. 21/10-17
1C tester, programmable (6502) 28/33-35
IM6100 7/10
I MSA I
hardware fixes
to RAM-4A 3/6; 13/7
for memory clobberer 8/17; 16/60
Intel-NEC chip differences 10/14-15
index
to The Computer Hobbyist 5/26-27
interface
cassette (6502) 27/31 -33
floppy disk (8080) 12/12-17
IEEE 488 bus (6800) 16/31 -55
ISIS (operating system), analysis of 21/10-17
James, John S. 25/21-27; 28/26-27; 28/36-37
Julich, Paul M. 30/40-41
KAPIAR (macroprocessor) (8080) 20/31 -59, errata 23/3
Kee, Henry L. 9/23; 12/5
Kelb, Carl 7/26-27
Kendall, Bruce R. 16/22
Kernel (operating system) (8080) 18/20-40
Kheriaty, Larry 27/46-47
Kildall, Gary A. 22/10-13
KIM-1 (6502)
breakpoint routine 16/25-27
calculator, binary 23/13-15
cassette I/O 25/24-27, comments on 29/41
curve fitter (FOCAL) 30/12-14
disassembler 20/12-13
editor (for machine code) 25/34-39
graphics routine 14/32
programmable 1C tester 28/33-35
see also 6502; Apple-11
KIMATH (arithmetic routines)
extension to (6502) 20/15-21
Kushe, Willi 16/25-27
language, interpretive
for tiny BASIC 1/6-12
language, programming
comments on design of 3/7;3/15; 17/15
Dijkstra's (hacked up) 19/19-20
implementation ideas 17/16-17
miscellaneous 30/78+
for robots (8080) 18/8-19; 25/17-20
translation techniques 25/4-16
see also ACT; APL; BASEX; BASIC; CASUAL; EMPL;
FOCAL; FORTH; GPM; HI; KAPIAR; LISP; MINOL;
NIBL; PASCAL; PILOT; SAM76; SCELBAL;
STRUBAL
Laughlin, Neils 19/19-20
Laurer, G.J. 14/36-43
law 28/36-37
LAZARUS (erased program recoverer) (6502) 26/31-33
LEDIP (text editor) (6502) 29/4-12
linkage editor, see relocator
LISP
for 6800 28/24-25
for 8080 30/4-11
list processing
article on 24/4-8
LLL BASIC, see BASIC: LLL (Lawrence Livermore Labs)
loader
for 8080 3/16, 7/31
for SC/MP 21/13
Longtin, Brent 16/8-10
LSI-11, interface to S-100 bus 11/3
McCormick, Edward M. 19/30-35
MacDougall, John 22/42-43
machine-readable characters 15/45
McKeeman, William M. 25/4-16
macroprocessor
ACT (8080) 23/20-45, 24/27-46
GPM (6800) 20/22-29
KAPIAR (8080) 20/31-59, errata 23/3
SAM76 21/18-37;see also SAM76
Marek, Larry A. 27/42-45
MATHPAC (trig function routines): KIMATH extension (6502)
20/15-21
math programs, see arithmetic
memory clearer
for 6800 29/43
for 8080 8/32-33
memory dumper
for 8080 26/18-23; 27/4-18; (vocal) 28/42-46
(BASIC) 18/41
memory tester
for 6502 17/23; 21/4-5
for 6800 5/9; 25/28-33
for 8080 8/32-33
for Z-80 22/42-43
microcomputers
in electronic toys 16/24
microprocessor, see 6502; 6800; 8080; 8086; COSMAC (1802);
CP 1600; F8; IM6100; PACE; SC/MP; Z-80
microprocessor instructions, proposed 16760
Microsoft BASIC
renumbering program 27/34-38
Mills, Jonathan W. 19/21-27
MINOL (8080)
documentation and code 4/9-17, errata 6/36, 7/32
game
tiny trek 6/37, errata 7/31
Mits BASIC
modification for two terminals 9/24-25
modem
as cassette interface 10/7, 14/6-7, 19/S
driver 26/4-16, errata 27/43, comments 29/41-42
reviews
DC hayes board 20/5; 26/4-16, 27/43, 29/41-42
IDS board 26/4-16, 27/43
Pennywhistle 103 17/11-12, 17/13
Monagan, James 22/8-9
monitor
for 6502 7/20-21
for 8080 4/18-32
for COSMAC (1802) 19/30-35
Moody, Bob 16/15-16
Morgan, David J. 24/22-25
Mork, Phil 28/42-46
Morrow, George 25/40-46
Moser, Carl 21/4-5; 27/31-33
Mueller, Erik T. 4/9-17; 14/12-16
music
program (8080) 2/6-7, 3/6 8/32-33, 16/21
printing of 3/10-11
bibliography of computer music 7/33-35
networks
Digicast™ project 29/16-17
PCNET 17/7, 17/13; mentions of 26/4, 30/47
other: (D.C. area) 14/3; (EFTS) 16/61-62; (DEAFNET)
17/10; (bulletin board) 26/44
Newberry, Steve 20/31 -59
NIBUSC/MP)
documentation and code 10/34-50, errata 15/4
criticism 22/21 , response 26/45
Northstar 28/38-41
number systems
conversions
binary to decimal (algorithm) 1/2
octal to hex 16/13-14
hex to octal 16/13-14
hex vs octal 19/5; 22/45-46
miscellaneous 15/4
Nurse, Howard L. 28/30-32
Ockers, Stan 14/32
octal, see number systems
opcode decoding (6502) 17/20-22, 19/42-44; 22/5-7
operating system
CHAOS 6/3; 7/3
ISIS (analysis of) 21/10-17
Kernel (8080) 18/20-40
Unix™ 4/3, 6/3, 7/3
optimizing (a program) 22/5-7
OZNAKI project 13/12-13, 24/10-11
PACE
review of PACER 9/12-13
Pack, Charlie 4/18-32, 19/36-41
Palmer, John B. 18/41
Parker, Dan S. 14/10-11
PASCAL 23/16-19
PCM-12 (review of) 7/10
PCNET.see networks
Pearce, Craig A. 21/5
Peterson, Richard K. 13/36-37
Pfafman, Fred 13/7
PILOT
8080
code for 15/18-33
documentation 14/17-29
errata 19/18, 20/63
modifications
editor 22/43-44; 24/22-25
other 17/24
on North Star 27/26
Common 27/46-47
information exchange 14/17
tiny
proposal 13/34-35 , responses 18/43, 19/35
see a/so FOCAL
Pittman, Tom 6/9-10; 8/19-21; 12/3-4
Poduska, Paul R. 20/9-11
'polish joke'4/78, explanation 7/35
Poly88 (review of) 10/16-18
Polymorphic’s BASIC
review of 14/8-10
printer driver for 27/27-30
Polymorphic’s documentation, corrections 19/15-17
Poly VTI. 13/12-13; 16/17-19
POW(word processor) (8080) 29/18-29
printer
driver routines (8080) 14/10-11, 19/35; 27/27-30
(6800) 12/7
Processor Technology
BASIC
INT function fix 8/34; 10/9, 13/4; 17/26
tape load/save 16/23-24
assembler fix 13/7; 16/22
G.P. Memory module fix 27/41
programming languages, see languages, programming
programming tricks 6/9-10; 28/29; 29/3
programs
miscellaneous
interactive peek/poke (BASIC) 22/8-9
stencil cutter (BASIC) 29/17
see also under processor type (for machine and assembly
language) or program type
Pugh,Tim 26/4-16
Purdin, Titus 28/38-41
Rankin, Roy 7/17-19
Raskin, Jef 13/25-29; also most reviews
reformator (intel to proc tech assembler) (8080) 6/10
relocating machine code
article on 22/10-13
rel ocator
for 8080 13/8-9; 22/14-20
for 6502 14/30-31
forZ-80 13/8-9
renumbering routines for BASIC 23/4-9; 27/34-38
reviews
computers
DZ-80 15/7
H-8 20/9-11; 30/22-25
PACER 9/12-13
Poly88 10/16-18, errata 13/5
miscellaneous 8/15-17; 14/46; 15/5; 18/5;24/19-20
modems 17/11-12; 17/13; 20/5
software
Mits BASIC, Poly BASIC and NIBL 14/8-10, errata
16/7. 17/31
other 20/29; 26/17
Rice, Lloyd 4/6-8
Ritter, Terry 25/28-33
robots 22/4; 18/8-19; 25/17-20
Roichel, Ancelme 21/18-37
Roth, Richard L. 22/14-20
SAM76 21/18-37; 23/46; 26/46-47; 30/19-21;30/44-45
Sanger, Joseph Jay 15/10-17
478
Santore, Ron 6/38-39; 16/23-24
Savir, D. 14/36-43
SCELBAL 2/8-12
schedule program (BASIC) 16/15-16
Schuman, Philip 17/35-37
SC/MP
loader 21/13
language
NIBL. see NIBL
subroutine manager 13/36-37, 30/44
Scully, Tim 22/43-44
Selectric: converting to an I/O device 13/41-44
Shaw, Dan M. 13/8-9
Shepard, John C. 5/10-11
Sherman, Ralph 14/30-31
Simmons, Webb 21/8-9
Simpson, Philip 22/30-41
Skovgaard, Erik 21/13
Smith, Glendon 6/30-33
Smith, R. Lynn 12/25-27; 16/57
Smith, Stephen P. 21/6
Snell, John 7/33-35;9/12-13
software
editorial on 12/3-4, response 16/7, 16/8-10
piracy 5/3;19/20; 22/20; 25/3
SOLI8080)
disassembler for 21 /38-46
file routines for ALS-8 27/42-45
patches to run Mits BASIC 18/42-45
sort routine (quicksort) 24/20
speaker, using TV, for computer output 12/4
speech
digitizing 28/42-46; 29/30-33
synthesis
article on 4/6-8
reference to paper on 8/9
products 3/12; 5/7-8; 8/7-8; 20/6-8
Stallings, Gordon 13/30-33
standards
proposed
memory map 9/22
S-100 bus 7/8-9; 25/40-46
Z-80code 13/10-11 , response 17/34
Starkweather, John A. 14/17-29; 15/18-33
status push/pop (8080) 29/3
Stedman, John O. 9/16-18
Stiefel, Mai 7/12-15
string output routine(6502) 8/33, 10/50, 12/8
STRUBAL 23/10; 28/28. 30/44-46
structured programming
article on 21/8-9
Stumpf, Adolph P. 2/34; 10/9; 13/4
Suding, Robert 1/18
Swank, Joel 28/33-35, 30/32-33
SWTPC
6800 I/O control interface 17/35-37
miscellaneous 20/30
Teeter, John 11/8-61
telephone, see also networks
telephone company 7/36-37
terminals
for trade 16/14 , retraction 17/10
Singer/Friden/Burroughs 10/9; 12/27; 15/5; 17/33
Terry, J.M .24/4-8
text editor
for 6502 29/4-12
for 8080 6/13-26
Thompson, Bill 6/11-12
timer routines
for 6800 9/21
for COSMAC (1802) 19/30-35
tiny BASIC, see BASIC, tiny
tiny BASIC extended, see BASIC, tiny: Texas
trace routine (Z-80) 23/11-12
tree, binary
manipulation routines (8080) 30/15-17
Trenholme, John B. 27/34-38
TVT-II
driver (8080) 2/34
see also hardware: modifications
TV. see display
TV Dazzler. see graphics: 8080: dazzler
Uni vac II
article on 28/20-23
Unix™ (operating system) 4/3. 6/3. 7/3
utilities see under type of processor, computer or utility
Van Buer, Darrel 14/6-7; 30/4-11
Van Der Wateren, Frits 28/24-25; 20/22-29
Van Dyke, Don 21/38-46
Van Valzah, Bob 10/19-32, 12/44-45
Wadsworth, Nat 2/8-12
Wang, Lichen 5/12-25; 6/8; 17/33-34 ; 18/8-19
Warme, Paul K. 30/26-31+
Warren, Jim C., Jr.
editorials 2/3; 3/3; 4/3; 5/3; 7/3; 9/3-4; 10/3-4
other 4/5; 8/3-6; 9/6-7; 11/7; 16/5-6; 29/16-17
Watson, Herman 29/18-29
Wayne Watch 16/5-6
Weisbecker, Joe 15/34-44
Whatis (expression evaluator) 29/34-40
Whipple, Dick 1/13-17; 2/13-31
Wilcox, Bob 3/6
Wilcox, Dick 11/3-7
Williams, Steve 16/15-6
Williams, Tom 19/6-9; 30/22-25
Winzenread, Marvin R. 8/28-29; 9/30-31; 10/58-59; 10/60;
15/9; 16/28-30
Witham. Steve 17/16-17
word processor
for 8080 29/18-29
Wozniak, Steve 7/17-19; 8/22-25; 8/26-27; 23/4-9
Yob, Gregory 22/22-29
Young, Kenneth 20/6-8
Z-8
article on 26/28-30
Z-80
differences Zilog-Mostek chips 19/9, retraction 21/13
disassembler (BASIC) 26/42-44
miscellaneous 7/11
patches
for Microsoft 8K BASIC 12/20
for Mits 12K BASIC 17/25
utilities
debugger 24/12-18
memory tester 22/42-43
miscellaneous 27/22-26
relocator 13/8-9
trace troutine 23/11 -12
see also 8080
Zeigler, John 3/17-19
Zolman, Leor 26/34-41
479
5490-4
$18.95
\
[»
HAYDEN BOOK COMPANY, INC.
Rochelle Park, New Jersey
ISBN 0-8104-5490-4
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11