fourth chapter provides a detailed description of the Northwestern Chess Program , currently the national champion .
The fol lowing three chapters discuss several alternative approaches to chess program
ming. In the final chapter, a former cap
tain of the U.S. Olympic chess team asses
ses the present status of chess s ki l l in human and machine. 2 1 7 pp. $ 1 4.80 hardcover.
1 975 U.S. COMPUT E R C H ESS C H AMPI O NS H I P by D avid Levy.
0 The sixth annual U.S. Computer Chess Champi onsh ip, hel d in October 1 975, was a tou rnament i n which twelve computer pro
grams competed against each other. This book includes a detai led analysis and description of all the games, presented by David Levy, the tournament di rector. 86 pp. $5.95.
Chess
and.Computers .
C H ESS A N D COMPUTERS by David Levy.
0 If you enjoy p laying chess, then you will thor-oughly enjoy this book, which is l oaded with chess games played by computers.
The first chapter descri bes the earl iest chess "ma
ch ine," the famous Auto
maton chess player that toured E urope and America.
There is a detailed accou nt of Torres y Quevedo's in
vention that p l ayed the anding of K i ng and R ook agai nst King. There is also a description of how com
puters p lay chess, i ncluding an account of early Soviet attempts at chess program
m ing that contains much information h i therto u npub
l ished outside the Soviet Union.
Many ex amples of computer play are given, which provide an excellent i nsight i nto the problems facing chess program mers. 1 45 p p. $8.95.
1 976 U.S. C O M PUTE R CH ESS C H AMPI O N S H I P by D avid Levy.
0 This book includes a detai l ed analysis and des
cri pti on of a l l the tournament games played at the seventh annual U .S. Chess Championship held i n Octo
ber 1 976. 90 pp. $5.95.
AN E D ITO R /ASSE M B L E R SYSTEM F O R 8080/8085 BAS E D CO MPUTE RS by WJ Weller and W T Powers.
A N B k!
0 This 1 48-page book contains complete i nformation for i n itial izing and using a p owerful new eW 00
editor/assembler and debuggi ng monitor system , and the fu l l S O U R C E text of both . The
assem-bler fu l l y supports a l l I ntel i nstruction m nemonics as wel l as the entire language used in P R AC-
\g: ¥lt;
T I CA L M I C ROCOMPUTE R P R OG RAMM I N G™ : T H E I NTE L 8080. The editor/assembler is :�:\:· ;;;
resident in less than 8 K RAM and wi l l ru n on any 8080, 8085 or Z80 based computer with peri
pherals wh ich transfer on a character by character basis or can be made to do so by buffering.
The user supp l ies his own 1 /0 d rivers. The text editor is extremely simple to use and d oes not req u i re irrelevant l ine n u m bers. Also incl u ded is a program to convert Processor Technol ogy TM format tapes to a format useable by the editor/assem bler.
This system is n ot the usual "q uickie" software, riddled with errors and l i m i tati ons, but a professionally created, thoroughly tested and debugged system. At $ 1 4.95 it is the best soft
ware barga i n you are ever l i kely to see.
A N D BY T H E WAY . . . paper tape object copies of a l l of this software are sent F R E E to book purchasers when the coupon at the back of the book is returned to Northern Tech nol ogy Books. 8Y:! x 1 1 format. $ 1 4.95.
F o r y o u r convenience in order
ing, please use th is page plus the order form on page 13 8.
STAN D A R D D I CT I O N A R Y O F COMPUTE R S A N D I N F O R MAT I O N P R O C ESS I N G 2nd Edition by Martin H Wei k.
D I A L Y O U R BA N K C A R D O R D E RS TO L L F R E E (800) 258-54 77.
BITSinc
Circle 3 5 o n i nquiry card.
0 This is a very complete, fu l ly cross-referenced d ictionary . It goes a step farther in that it i ncl udes fu l l explanations, practical examples, many perti nent i l l ustrations, and suppl ementary information for over 1 2,500 hardware and software terms. It cross-references the terms to other cl osely related concepts, and appended to each defi niti on , as the need arises, are explanations, tutorial i nformation, examples, usage areas, and cross-references for further clarification of con
cepts and meani ngs. 390 pp. $ 1 6.95 hardcover. ( N o photo)
BYTE December 1978 155
Listing 7, continued:
1 56 December 1978 © BYTE Publications Inc
t• SEMA N T IC S • P I ECE NDVED • 1
Text continued from page 144
A second and somewhat more challenging project would be to develop a transposition table for the program. This requi res the availabil ity of u nused memory (at least 8 K
bytes and preferably 1 6 K or 3 2 K bytes),
an efficient h ashing scheme, and a set of decision rules to select among positions when a col lision occurs (ie : two positions hash to the same address in th e table).
Another problem is that the use of a staged eval uation process and the a-(3 algorithm
often provides an im precise evaluation score
(ie: the machine has determined that a posi
tion was not optimal but h as not invested the time to fin d out exactly h ow bad it was).
If the programmer succeeds with the trans
position table, however, m ove calculation will take 30 to 50 per cent l ess tim e in most middle game positions and 60 to 90 per cen t
less time in many end game positions.
A third area for improvement is the eval
uation function. Our program presently has only a rudimentary fu nction. The reader shoul d compare it with the one used by Chess 4.5 which is described in detail by Slate and Atki n . Their evaluation function provides an excell ent starting point for re
vising our present function. I n part 4 we wil l discuss the advantages o f usi n g a conditional eval uation fu nction, ie: one that changes de
pending on the stage of the game and on th e presence of special features. One im plemen
tation of this strategy is the special end game program described by Monroe Newborn in
Chess Skill in Man and Machine.
It is appropriate for us to add two i m por
tant disclaimers at this ju ncture. Alth ough we have carefully tested each of the rou
tines in the p rogram and played several chess games, it i s still possi ble that there are a few mi nor bugs in the program. If you fi nd one, a letter to one of us or to BYTE would be appreciated. Secon dly, our chess program was written primarily for pedagogical pur
poses. For th is reason it is not a production program and does not run very efficiently.
If you are the com petitive type, our p rogram shou l d provide many useful i deas, but you should not expect it to compete successfully in tournament play u nless you make exten
sive modifications and additions.
A chess program h as a tendency to grow and change its personality as the program
mer becomes more famil iar with each of its many l imitations. It provides a constant challenge for those of us who are too com
pulsive to tolerate obvious weaknesses. I n fact one must b e carefu l not t o become total ly obsessed with this project. We do not wish any of you to lose your job or your spouse because of a chess program .•
Circle 70 on inquiry card.
The North Star Horizon Computer System.
(With wooden cover and all standard items . ) Item
Code Description N S - H - 1 Horizon 1 kit N S - H - 1 I A Horizon 1 Assembled N S - H - 2 Horizon 2 kit NS-H -2/A Horizon 2 Assembled North Star S-100 Boards
NS-ZPB Z·80A 4 mhz Processor kit
List Cash Price Price
$1599. $1 299.
$ 1 899. $1559.
$ 1 999. $1 639.
$2349. $1 926.
NS-ZPB/A Z-80A 4 mhz Processor Assembled
$ 1 99 . s 163.
$ 259. s 212.
$ 399. s 327.
$ 459. s 376.
N S - 1 6K 1 6K 250ns RAM kit NS- 1 6K/A 1 6K 250ns RAM Assembled
P 0. Box 71 F ayettev i l le, N Y 1 3066
It 's A Great Big Computer World . . .
. . . but you only need The Computer Corner
Don't know "bytes" from "bagels"?
The courses given in o u r Seminar Room w i l l get you "up and running".
From home computerists to busi
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We offer classes with a hands-<Jn approach u s i n g various m i
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Circle 65 on inquiry card. December 1 978 © BYTE Publications Inc 1 57
Continued from page 1 0
recovery from transmission errors. Add to this the fact that the protocol has he did a good job of explaining the sub
ject. While I realize that he was pur
com-plex problem can be handled with small, easy to understand pieces of code. One of the thoughts about module size is, therefore, that a module ought to be able to fit on one printed page. This is so that all the information about the module is in one place and the pro
grammer won't have to thumb through several pages to read the code for a single module. Having experienced "modules"
running as long as 1 0 to 1 S pages, I heartily agree with this philosophy.
I n professionaf programming instal
lations, this idea has frequently been translated into a local standard of about SO lines of code, since this is the number of lines which are printed on an 8.5 by 1 1 inch (21 .S9 by 27.94 em) page coming out of a l ine printer (allowing for headers, footers, etc). For the personal computer enthusiast, however, this limit might be more conveniently the programmer's ability to understand the code. small business computer products and services
• The monthly magazine for businessmen in the process of purchasing or installing their first com
puters.
• The practical how-to publication written in non-technical language and stressing business applica-tions for small computer systems. Each monthly issue includes:
FEATURE SURVEY REPORTS: Such as. Software Packages for Small Business Applications.
Small Manufactunng Systems. lnuentory Control Systems, Microcomputer Business App/iactions, and so on.
APPLICATION STORIES: Real-life examples of computer applications in the small business en
VIrOnment - capabilities, benefits. what to watch for. and much more of direct interest to the small busmessman.
COMPUTER PROFILES • IDEAS AND INNOVATIONS • INFORMATIVE ADS
SPECIAL CHARTER SUBSCRIPTION
12 issues @ 50% off Receive the next 12 issues of Small Business -1 58 December 1978 © BYTE Publications Inc ,Circle 328 on inquiry card.
.. .. • T
L I G H T S E E K I N G ROBOT I enjoyed your "On Building a Light
Seeking Robot Mech anism " article (August 1 978 BYTE, page 24). The
lished and checked against current values. We must be careful to avoid lim
iting the robot to human perceptions.
john G ledhill 678 Washington Av #4 Yuba City CA 95991
C I A RC IA 'S C I RC U IT C E LLAR I am not one for writing to a maga
zine, but your article " Let Your Fingers Do the Tal king" (August 1 978 BYTE, page 1 S6 , and Septe m ber 1 9 78 BYTE, page 94) was right o n ! I read magazines and use the ideas and never let editors know. I sometimes write the authors.
Mr Ciarcia's article was just the best idea for a teacher like me.
I have been trying to get such an idea
scribed in the article. They are US patent numbers 3,775,560 and 3 ,860,764. My touch panels commercially, they will need a license under our patents.
These patents have already been licensed to several com panies in the US and their foreign counterparts licensed abroad. We are willing to provide