Sound Synthesis And The Personal Computer — Past Present And Future
$2,50 January 1983 Issue 32 Vol. 5, No. 1
63379 £1,85 in UK
COMPUTE!
The Leading Magazine Of Home, EducaHonai, And Recreational Computing
Music, Sound, And The Personal Computer
19 >
Music And Sound For VIC, Apple, Atari, PET/CBM, And The Sinclair/Timex
The Juggler, Thunderbird: TWO Exciting Gome Programs For ViC-20 Atari, And TRS-80 Color Computer
Writing Transportable BASIC Programs For Personal Computers
A New Monthly Column: Programming Ttie TI-99/4A
A Home Energy Calculator For Atari, Apple, VIC-20, PET/CBM, And Commodore 64
a 1
"74470'l63379
Plus Reviews For VIC, Atari, Apple Sinclair, And PET/CBM
"NEVER
forgets:
MORE THAN JUST ANOnn PREm nCE,
Says who? Says ANSI.
Specifically, subcommittee X3B8 of the American National Standards Institute (ANSI) says so. The fact is all Elephant^'^ floppies meet or exceed the specs required to meet or exceed all their standards.
But just who is "subcommittee X3B8" to issue such pronouncements?
They're a group of people representing a large, well-balanced cross section of disciplines— from academia, government agencies, and the computer industry. People from places like IBM, Hewlett-Packard, 3M, Lawrence Livermore Labs, The U.S. Department of Defense, Honeywell and The Association of Com- puter Programmers and Analysts. In short, it's a bunch of high-caliber nitpickers whose mission, it seems, in order to make better disks for consumers, is also to
make life miserable for everyone in the disk-making business.
How? By gathering together periodically (often, one suspects, under the full moon) to concoct more and more rules to increase the quality of flexible disks. Their most recent rule book runs over 20 single- spaced pages— listing, and insisting upon— hundreds upon hundreds of standards a disk must meet in order to be blessed by ANSI. (And thereby be taken seriously by people who take disks seriously.)
In fact, if you'd like a copy of this formidable docu- ment, for free, just let us know and we'll send you one. Because once you know what it takes to make an Elephant for ANSI . . .
We think you'll want us to make some Elephants for you.
EEPHANT. HEflTYDUTYDISKS.
For 0 free poster-size portrait of our powerful pachyderm, please write us.
Distributed Exclusively by Leading Edge Products, Inc., 225 Turnpike Street, Canton, Massachusetts 02021
Call: toll-free 1-800-343-6833; or in Massachusetts call collect (617) 828-8150. Telex 951-624.
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V
Ifitrodttcifig Snooper Troops
detective series.
Edticatioiial games that turn ordinary
homes into Sherlock homes.
Where can you find educational games that your Kids will really enjoy playing?
Elennentary, my dear Watson. From Spinnaker.
Our Snooper Troops detective games are fun, exciting and challenging. And best of all, they have real educational value. 5o while your kids are having fun, they're learning.
As a Snooper Trooper, your child will have a great time solving the mysteries. But it will take some daring detective work. They'll have to question suspects, talk to mysterious agents, and even search dark houses to uncover clues.
The Snooper Troops programs are compatible with
-JSix
Apple,® IBM* and -..
Atari® computers and
provide your kids with everything they
need; a SnoopMobile, a wrist radio, a
Snoophet computer, a camera for taking
Snoopshots and even a notebook for
keeping track of information.
Snooper Troops detective games help your children learn to take notes, draw maps, organize and classify information and they help develop vocabulary and reasoning skills. All while your kids are having a good time.
So if you want to find educational games that are really fun, here's a clue: Snooper Troops games are available at your local software store, or by wnting to; Spinnaker Software, 215 First Street Cam- bridge, MA 02142.
e 5plnnaher Soltuwre Corp. 1982
Spinnakeiis early learning games will help make your children as smart as yon tell eyeryone they are.
Your kids are pretty smart. '^Sfe^.
After all, they're your kids.
Spinnaker can help make them even smarter With a line of educational software thatklds love to play
Spinnaker games make the computer screen come to life with fulf color graphics and sound. And they're fun. Lots of fun. But they also have real educational value.
Some of our games help exercise your child's creativity. Others improve memory and concentration. While others help to improve your child's writing, vocabulary, and spelling skills.
And every Spinnaker game provides familiarity with the computer and helps your children feel friendly with the computer Even if they've never used a comput- er before.
And Spinnaker games are compati- ble with the most popular computers: Apple,® Atari® and IBM*
Our newest game, KinderComp"* (Ages 3-8) is a collection of learn- ing exercises presented in a fun and exciting manner.
Sj^^ '^^ Rhymes and Riddles'" "• " ' (Ages 4-9) is a letter guess-
ing game featuring kids' favorite riddles, famous say- ings and nursery rhymes. Story Machine'" (Ages 5-9) lets children write their own stories and see them come to life on the screen. And rACEMAt^ER'" lets your children create their own funny faces and make them wink, smile, wiggle ears (not your kids' ears, the ears on the screen), etc. And we're intro-
ducing new games all the time.
So look for Spinnaker games at your local software retailer or by writing to: Spinnaker Software, 215 First St., Cambridge, MA 02142. And show your kids how smart their par- ents really are.
We make learning tun.
Apple, iBH arid Atari are registKM tradeirwhi or Apple Computer, inc., IfNteffTflUpfui Btomtto nacfurvea Corp arvi Aiao. ux . rewecuvety
THE ONLY CHOICE FOR SERIOUS ATARI* OWNERS 1
iTiR^OSOIC
ELEaRONlCS, INC
January 1983 Vol. 5, No. i
FEATURES
26 Sound Synthesis Tom R. HalfhiJI
36 Writing Transportabfe BASIC Ecfward T. Ordmon
43 Mattel's New Home Computer Tom R. Halftiill
48 Atori's Sound System Jotin Scarborough]
52 VIC Sound Generator Robert Lee
56 Easy Apple Disk Space Messages Beirne L Konarski
EDUCATION AND RECREATION
58 Juggler Doug Ferguson
68 Sound On TheSinclair/Timex Arttiur B. Hunkins
71 Thunderbird Dave Sanders
84 Home Energy Calculator David Swaim
101 Waretiouse Automation Witti Personal Computers Timotl^y Stryker
126 Chiristmas Bird Count Jean B. I^ogers
134 Higti Resolution Turtle Groptiics David D. Ttiornburg
REVIEWS
136 Apple Educational Games Stieila Cory
138 Promqueen , Harvey B. Herman
140 Preppie- For Atari MikeKinnamon
142 Player ZX-81 ArttiurB. Hunkins
143 PET/CBM StandOfd Terminal Communications Package Harvey B. Herman
145 A Financial Wizard For Atari TinaHolcomb
COLUMNS AND DEPARTMENTS
6 The Editor's Notes Robert Lock
10 Ask The Readers The Editors And Readers of COMPUTE!
18 Questions Beginners Ask Tom R. Halfhill
21 Computers and Society David D. Tbornburg
44 The Beginner's Page: Myths About Programming Richard Mansfield
108 Friends Of The Turtle David D. Thornburg
116 The World Inside The Computer:
New Improved Computer Friend For Your Apple Fred D'Ignazio
119 Learning With Computers: Gentle Introductions To Programming Glenn M. Kleiman
124 Micros With The Handicapped:
Devefoping A Communications Program Susan Semancik & C. Marshall Curtis
171 Insight: Atari Bill Wilkinson
178 Telecommunications: Computers And Communication Michael Day
180 Machine Language: Speed Demon Jim Butterfield
183 Programming Ttie Tl C. Regena
187 Extrapolations: Tap ApplesofTs Heartbeat Keith Folkner
THE JOURNAL
146 Automate Your Atari Joseph J. Wrobel
-153 All About Commodore's WAIT Instruction Louis F. Sander
-156 WAITing On The VIC-20 And Commodore 64 Doug Ferguson
160 Apple Machine Longuage Memory Aid K, Lourash
-162 Supermon64 Jim Butterfield
186 Copy VIC Disk Files Roger L.Smith
191 Atari Lister Leroy J. Baxter
192 Pertect Commodore INPUTS Btaine D. Standage
196 Atari Aufonumber Barry Bernstein
198 VIC Super Expander Graphics Tim Parker
202 Download/Upload For The Atari Frank C.Jones
208 Commodore 64 Architecture Jim Butterfield
213 VIC Pencil Ken Bowd
216 Atari's Exponents MottGivi/er
217 ViC Personal Accountant Peter Mendall
220 CAPUTE! Mod if ications Or Corrections To Previous Artie les
222 How To Type COMPUTEI's Programs
223 A Beginner's Guide To Typing In Programs
225 Nev;:. ^ .'^roJijcis
236 Calendar
NOTE: See page 222 before typing in programs.
GUIDE TO ARTrCLES AND PROGRAMS
AT
V AP
ATA/ ZX
C/ATA/
P AP
AP V AT ZX
P AT
AP/PA/ AT
n
AP
AT PA//64 V/64
AP
64
V
AT P/V/64
AT
V
AT
64
V
AT
V
AP Apple, AT AtarLP PET/ CBM,V VIC-20, OOSl C Radio Shack Color Com- puter, 64 Commodore 64, ZX Sinclair ZX-81, ' All or several Of the above.
COMPUTE! The Journal for Progressive Computing (USP.S: .")372riO) is piihlislicct 12 times eacli ve;ir1)\ Siniill SvsiL-m SiTvicts. liK.. I'.O. lidx fitim. CJrcenslmrcj. NC 27-4(0 U.SA. I'Ikiir-: l!ll>ir-'7.")-;iH()<l. l-;diu>ri;il Oltiii-s jti- Iik;i1c<I m r>2.') I*'uli*iij Sirt'ct. (.ireonsfjijfd. NC: 27WS. Donie&ilc Subscripticms; I'J isMn->. 521). DO. St-iui Jiiiljsuipiion (jriicrs or tliiingf of iiddrcss (I'.Cl. foriii 3.i79l to C:iri;u!:iiion Dt-jjt.. COMPUTE! Mui>.i/!iii-. I'.O. Box .VKMi, Grccnsburo, KC. 1^7 Hi;i. SltuikI class jjostagcpaid iii Ciieetisboro. NC:!J7-i(i:i .iiid jdditicjiijd iii.iiliiii; otjitcs. fcln^^rcL^nEcntscop^^i^^ll t \W> 1)1 SiiiHil Svstcrll Services, lin. .All ri^iit.s rcst-rvrd. 1S.S\ IM U t-:ir)7\.
TOLL FREE
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EDITORS NOTES
Announcing A Significant New Magazine From COMPUTE! Publications.
We've promised that 1983 would be an exciting year and are now willing to divulge one of the reasons why. The Commodore Gazette''" will premiere as a monthly in the spring of 1983. The Gazette will not impact COMPUTE! editorially or alter the current scope of COMPUTE!. The Gazette is planned as a layper- sons's guide to consumer com- puting. It will.be written for be- ginning and intermediate level owners and users of the VIC-20, 64, and Ultimax computers. Reg- ular features will include best seller lists for recreational and educational software, reviews, new products, tutorials on home and educational applications, and much more. Written for entertainment as well as educa- tion. The Commodore Gazette, while appealing to users wishing to learn more about program- ming and computers, will also have continuing appeal for those who simply want to obtain maximum use from their com- puters in a non-technical way. Next issue we'll give you full details on the new magazine. COMPUTE! will continue to pre- sent its normal excellent range of information for the VIC-20 and Commodore 64.
A Call For Editors
COMPUTE! Publications, both our magazine and book pub- lishing divisions, is looking for experienced staff members for our growing editorial needs. If you've been writing for COMPUTE!, or if you have mean- ingful editorial experience, we'd
6 COMPimi January. W83
like to see a resume as soon as possible. We're specifically in- terested in writers with experi- ence using Atari, VIC-20, and related computer hardware. We are a progressive and growing company, with an excellent working environment and bene- fits, located in the attractive Pied- mont area of central North Carolina. If you're interested, please send a resume along with work history, salary expecta- tions, and other pertinent infor- mation to Kathleen Martinek, Managing Editor, COMPUTE! Publications, Post Office Box 5406, Greensboro, NC 27403. Your inquiry will be treated with complete confidence. Mark the envelope "Personal and Confi- dential," please. Remember to include samples of your writing.
We cannot accept any tele- phone calls prior to submission of a resume, and will deal only with the individual interested in the position. We do not wish to work with personnel agencies.
Random Asides
You'll notice several enhance- ments in this issue as part of our continuing quest to better serve our readers. Among these are additions aimed at beginners, "Questions Beginners Ask" and a revised section on using our program listing conventions will become regular features of COMPUTE!, , , . We're setting new records again. Press run for this issue is an astonishing 156,000 magazines. We had to declare October, November, and Decem- ber sold-out within weeks of pub- lication date. It was only a few months ago we were collectively applauding the 100,000 mark...
New personal computers are on the way from Mattel and NEC, among others,,. Atari may be dropping the rumored 600 given recent changes in competitor pricing. Look for a new com- petitor to the Commodore 64... Magnum publishes a monthly list of the 100 best-selling com- puter books in the US. It's com- piled from industry sources. COMPUTE! Books has five titles in the top 100, and COMPUTEl's First Book of VIC is number one for the second month in a row.
Reader Service Cards
A first for COMPUTE!, In the back of this issue, you'll find reader service cards for the very first time. Use them to request additional information from ad- vertisers. Simply look up the advertiser in the advertising index and circle the appropriate number. Remember though, if you're in a hurry to contact a particular advertiser, it's prob- ably best to write or call directly,
COIVIPUTEI's New Look
As you'll notice as you explore this issue, we've made some subtle and significant changes in the overall design of the magazine. We think you'll find COMPUTE! even easier to read and enjoy. Thanks to everyone here for helping implement those changes.
The Home Accountant: The ^1 best-seller.
'-Sfe
Any home finance package will balance your checkbook. But to become the #1 best-seller you've 90t to be somethins special.
The Home Accountant™ is.
It's the only one that prints a net worth statement and a personaFfinance statement. So you know exactly where you stand financially every day of the year. It will even print your checks, automatically
Notonly that,The HomeAccountant™ lets you label every transaction. Just imagine sitting down to do your taxes and having every penny you've spent and earned neatly listed by category —and available at the touch of a button. It's an incredible time-saver.
You can also create bar, line and trend analysis graphs for every category— in color. It's great for realistic budgeting.
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Let's say you write a check to pay your Visa.The Home Accountant" automatically debits your checking account and credits yourVisa account.
And it does this with every one of the two hundred* budget categories; credit cards, checking accounts, money markets, cash, rent checks, insurance payments— you customize your own financial package.
Check out The Home Accountant" soon. You'll find it does a lot more than simply manage your money.
It manages your money simply.
*The Home Accountant" is available for the Apple il/IBM Personal Computer/Atari 400/ 800 Computers/Osborne/TRS 80 Model III / Commodore VIC64.The actual budget capacities will vary with each computer.
Continental
Software
A Division of Arrays, inc.
<^=£J^
-_v~— n erf Wamc Cooununicmont.lncOibomc 11 a rcy.tf
VIC &« n • itirtWM RMMmcrfe of COflMWdo'* luuncii M«chinci, Im
p j It sells the most, because it does the most!
Continental Software Co.,11223 South Hindry Avenue, Los Angeles, California 90045 Telephone (213) 417-3003 • (213) 417-8031
Publisher/Editor-in-Chief RobertC, Lock Publisher'sAssistant AliceS.Wolfe
Senior Editor Managing Editor Features Editor lectin ical Editor Editorial Assistant Program m ing Assistant Administralive Assistant CopyAssistonts
Associate Editors
Ricfiord Mansfield Kottileen E. Martinek TomR.Halfhill Ottis R. Cowper Ctiaries Brannon Patrick Parristi Vicki Jennings Juan ita Lewis Mary Parker Jim Bufterfield, Toronto, Canada Harvey Herman, Greensboro, NC Fred D'lgnazio: c/O COtvlPUTE!, P.O. Box 5406 Greensboro, NC 27403
David Thornburg P.O. Box 1317, los Altos, CA 94022 Contributing Editors Marvin DeJong Bill Wilkinson GeneZumctiak
Arl Director/ Production Manager Assistant Artists
Typesetting Illustrator Production Assistant
Georgio Papadopoulos
irmaSwain
De Potter
Jean Hendrix
Terry Casti
Horry Sloir
DoiRees
Associate Publisher/
National Advertising
Soles ti^anager AndyMeehon
Advertising Coordinator /Mice S.Wolfe
Ad vertising Accou nts Bonnie Valentino
Sales Assistant Rosemarie Davis
Operations/Customer Service Manager Coordinator Assistants
Stiipping & Receiving
Carol Lock Ffon Lyons Ctiristine Gordon DorottiyBogon Gail Jones Ctiris Potty Patty Jones Jim Coward Lorry O'Connor
Accounting Manager Bookkeeper Accou nti ng Assistant Assistants
W. Jerry Day Ellen Day
Linda Roquemore Doris Hall Rutfi Granger Anno Harris
Small System Services, Inc. publlsties:
COMPUTE!
ThaJewnelFwn
COMPUTE! Books
Corporate office:
625 Fulton Street. Greensboro, NC 27403 USA
Mailing address: COMPUTE!
Post Office Box 5406 Greensboro, NC 27403 USA
Telephone: 919.275-9809
Robert C. Lock. President W. Jerry Day, Vice-President and Comptroller Kattiieen E. Martinek Assistant To Ttie President Sonja Wtiitesell, Executive Assistant
Coming In February
Special Games Issue:
How The Professionals Program Games
Four Exciting Games: Mastermaze, Slalom, Copycat, And A Day At The Races
VIC And PET High Resolution Plotters
Atari SuperFont Plus And Left-handed Joysticks
Apple High Resolution Painter
Color Computer Relocation Calculator
Subscription Information COMPUTE! Circulation Dept. P.O. Box 5406 Greensboro, NC 27403
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^^""' '■•.-/COMPUTE'
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In British Coiurnbia. Canada, Alaska Of Hawaii call 4QB-354-5553. Elsewhere In Canada or outside North Americo coll 919-275-9609,
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The Glttelman Company The Gittelman Company
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Address alt advertising materiaisto:
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COMPUTE! Magazine
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Auttiors of manuscripts warrant that all materiols submitted to COMPUTEi are originol materials with full ownership rights resident in said outhors By submitting articles to COMPUTE!, authors acknowledge that such materials, upon acceptance tor publicotion, become the exclusive properly of Small System Ser- vices, Inc. No portion of this magazine may be reproduced In any form without written permission from the publisher. Entire contents copyright ■/ 1982, Small System Sen/ices. Inc. Rights to programs developed and submitted by auftiors are exploined in our author contract Unsolicited materials not accepted lor publication in COIvlPUTE' will be returned if author provides o self oddressea, stamped envelope. Program listings should be provided in printed form (new ribbon) as well as mochine reodable form. Articles should be furnished as typed copy (upper- ond lowercase, please) with double spacing. Eoch page of your article should bear the title of the article, date and name of the author. COMPUTE! ossumes no iiabiiity for errors in articles or advertisements. Opinions expressed by authors are not necessarily those of COfVlPUTEI. PET is a trademark of Commodore Business Machines. Inc. Apple is a trademark of Apple Computer Compony. ATAI?I is a trademark of Atari. Inc-
8 COMPUTE! Jonuory. 1983
AN INFORMATION MANAGEMENT SYSTEM FOR YOUR COMMODORE COMPUTER
InfoPro is a menu driven and interactive "information management" system for the Cornmodore 8032 computer. InfoPro uses "friendly" screen prompts tiiat "guide" you from function to function. Tfiis makes InfoPro unusually easy to learn and just as easy to operate.
For Mailing List applications InfoPro can print up to 8 labels across and even has a built in "structure" with fields already pre-set. This structure can easily be changed to fit many other types of office jobs.
Another extremely powerful feature of InfoPro is Super Scan. The Super Scan feature acts like an "electronic filing cabinet" and pro- vides the user with almost instantaneous access to the data stored in a file. The powerful Report Generator allows you to "seleel" infor- mation for printing based on up to 5 different parameters or criteria and to perform various math functions.
Another powerful and indispensable feature is InfoPro's ability to interact with the WordPro family of word processing programs. This provides the user with a "link" from the area of data information
WordPro and InfoPro are registered trademarks of Professional Software
management to the area of word processing, allowing the user to manipulate, sort, and select data by certain criteria, which can then be inserted into "personalized" letters, documents, overdue notices, etc. InfoPro will also allow you to ADD, DELETE or CHANGE your information "fields" any time you wish. This means that as your business changes, InfoPro has the flexibility to change with it.
As with all Professional Software products. InfoPro comes complete with a professionally written and fully-tested user oriented manual. InfoPro also includes a program ROM, and InfoPro System Diskette .
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51 Fremont Street Needham, MA 02194 Tel: (617) 444-5224 Telex: 951579
ASK THE READERS
The Editors and Readers of COMPUTE!
High Vs. Low Resolution
Could you explain the difference between hi-res and low-res graphics?
Mike Porter
The esseutjnl difference is that when a computer does not have the high resolution option, you are limited to a set of built-in graphics characters. These characters, like the letters of the alphabet, will be crisp and clear, but you cannot create your own special characters.
A great deal can he accomplished, however, by combining the different symbols of a built-in set. Cubes, stairs, and many other pictures can be created. It's like having perhaps 128 different shapes of paper. You can put them together in thousands of ways, but you can't customize them individually by cutting them 'with scissors.
High resolution, on the other hand, permits you to control the individual pixels (dots) anyzvhere on the TV screen. This means that you can create detailed figures of your oum design - perhaps the Greek alphabet or an image of a starship - and that curved lines will look more like true curves. High resolution generally adds to the price of a computer, but does provide more flexible graphics, more visual possibilities. Alternatively, it is usually possible to add an optional high resolulio)! capability to computers which do not offer it as a standard feature.
Typing Programs From COMPUTE!
I have seen several programs in COMPUTE! that have a "^ " symbol in them and there is no such character on my keyboard. Did I miss it in the instruction manual (I triple-checked)? This upside- down V has stumped me. Also, what is the "-" symbol for? 1 know that an underline means to type the shifted version of whatever character is underlined, but what do you do when "-" stands alone?
Jim Lockridge
The "^" symbol indicates an "up-arrow" symbol (^ ) on Commodore computers and represents "to the power of" something. Whenever you see it, type the key with the arroxo pointing upxvardsivith respect to thekei/board. Hold dozon the SHIFT key and hit the SPACE BAR when you see an underlined blank. See the "COM- PUTEI's Listing Conventions" page in each issue.
10 COMPUTEI Januory,i983
Atari 400: Can You Add Memory?
I am getting a computer in a few months, but I have a problem. Can the Atari 400 be expanded to hold more memory than it comes with? I con- stantly see ads for RAM expansion boards, but the ads for the 400 computer itself say "16K RAM (non-expandable)." Well, which is it?
Scott Bonder
Officially, the Atari 400 cannot he internally expanded. However, you can replace the 16K memory board inside your computer with a 32 or 48K board. Atari does not manufacture them, but several third party vendors do. There is even a 64K RAM board sold. Be aware, how- ever, that opening your Atari 400 to replace the board might void your warranty.
How Can Ctiips Address 128K?
I have two questions, one of which has been bothering me for some time. How can an 8-bit chip such as the new MOS 6509 and 6510 address more than 64K? Commodore's new P128 computer will have 128K RAM. How is this possible? Al- though the Commodore 64 has 64K RAM, you have stated that only 38K (52K for M.L.) is avail- able for programming. Does this mean that soft- ware that had been embedded in ROM in previous CBM machines must now be soft-loaded upon power-up, or is it contained in a plug-in ROM cartridge?
My second question is if programs written for the Commodore 64 will run on the P128, and vice versa. I am particularly interested in the com- patibility of the various plug-in cartridges that will become available.
Ron Dagostino
The 6510 chip will not address more than 64K of mem- ory. The 6509 can, however, through a technique known as "bank switching," whereby large blocks of memory (banks) may have the same addresses. The micro- processor must then select which to use from among the banks. Details on exactly how the 6509 snakes this selec- tion are not yet available.
In any case, the 64K limit on memory addressing is not because the 6500 family of chips are eight-bit processors. Rather, it is a result of the chips having 16 address lines (2^^ = 65536). For example, the 8086
lASTNiGHT We Exchanged Letters iwth
mom,Then had a party for Eleven people in nine different States
AND ONLYHADlOmSH ONE GLASS...
That's CompuServe, The Personal Communications Network For Every Computer Owner
And it doesn't matter what kind of computer you own. You'll use CompuServe's Electronic Mail system (we call it Email™) to compose, edit and send letters to friends or business associates. The system delivers any number of messages to other users anywhere in North America.
CompuServe's multi-channel CB
simulator l)rings distant friends together and gets new friendships started. You can even use a scrambler if you have a secret you don't want to share. Special interest groups meet regularly to trade information on hardware, software and hobbies from photography to cooking and you can sell, swap and post personal notices on the bulletin board.
There's all this and much more on the CompuSen,'e Information Service. All you need is a computer, a modem,
and CompuServe. CompuServe connects with almost any type or brand of personal computer or terminal and many communicating word processors. To receive an illustrated guide to CompuServe and learn how you can subscribe, contact or call:
CompuServe
Information Service Division, P.O. Box 20212 5000 Arlington Centre Blvd.. Columbus. OH 43220
800-848-8990
In Ohio call 614-457-8650
An H&B Block Company
Apple Compuier Inc., 20325 Matiani Awnue, Cupenino, California 95014
Vol. 1 No. 2
Foi the authoriaa Apple dealer nearest vou. call 800-538-9696 (800-662-92 38 in CilifornLa..>
Fruitful Connections*
There are more people in more places making more accessories and peripherals for Apples than for any other personal computer in the world.
Thanks to those people — in hundreds of independent companies — you can make the humblest 1978 Apple II turn tricks that are still on IBMs Wish List for 1984.
But now we're coming out with our very own line of peripherals and accessories for Apple* Personal Computers.
For two very gpod reasons.
First, compatibility. We've created a totally kluge-free family of products designed to take full advantage of all the advantages built into every Apple.
Second, servace and support.
Now the same kindly dealer who keeps your Apple PC in the pink can do the same competent job for your Apple hard-disk and your Apple daisywheel printer.
So if you're looking to expand the capabilities of your Apple II or III, remember:
Now you can add Apples to Apples.
Gutenberg would be proud.
Old Faithful Silent^'pe* has now been joined by New Faithfuls, the Apple Dot Matrix Printer and the Apple Letter Quality Printer
So now, whatever your budget and your needs, you can hook your Apple to a printer that's specifically designed to take advan- ^ \ -^^^ _^„-.* '■^8^ *^^^ ^^ features built into your
^\ ^R>-#'"*'^ lllllilii Apple. With no compromises.
VK Lp IpIL The 7x9 Apple Dot Matrix
^j^lH^ _^__,--'-''" Printer is redefining "correspondence
^-"^ quality" with exceptional legibility. 144x160 dots per square inch, it can ilso create high resolution graphics.
The Apple Letter Qualiry Printer, .''•[^which gets the words out about 33% raster than other daisywheel printers in its price range, also offers graphics capabilities. See your authorized Apple dealer for more information and demonstrations. Because, unfortunately, all : news fit to print simply doesn't fit.
A joy to behold.
The new Apple Joystick 11 is the ultimate hand control device for the Apple II.
Why is it such a joy to use?
With two firing buttons, it's the first ambidextrous joystick — just as comfortable for lefties as righties.
Of course, it gK'es you 360° cursor control (not just 8-way like some game-oriented devices) and full X/Y coordinate control.
Arid the Joystick II contains high-quality components and switches tested to over 1,000,000 life cycles.
Wliich makes it a thing of beaur^'. And a joystick forever
©1981 Apple QimpuiL-thK
^ the creek iwithout paddle?
Or Icic in space? Or down in the dunions?
W'TiaJever your games, you'll be hapE» to know that someone has fineJy come out with game paddlefbuilt to hold up under blisterilg fire. Without giving you blistersi
Apflle Hand Controller II game paldles were designed with one receit discovery in mind: claying games get I can squeeze very, very
ana
Peopl excited hard.
So we rugged to 3,000,1 them for h the firing side for m
Soyoi
ide the cases extra ised switches tested
[life cycles. We shaped ling hands and placed
itton on the right rear
;imum comfort. Il never miss a shot.
A storehouse of knowledge.
If you work with so much data or so many programs that you find yourself shuffling diskettes con- stantly you should take a look at Apples ProFile™ the personal mass storage system for the Apple III Personal Computer
TTiis Winchester-based 5-megabyte hard disk can handle as much data as 35 floppies. Even more important for some, it can access that data about lO-times faster than a standard floppy drive.
So now your Apple III can handle jobs once reserved for computers costing thousands more.
As for quality
and reliability, you need only store one word of wisdom: Apple.
Launching pad for numeric data.
Good tidings for crunchers of numerous numbers:
Apple now offers a numeric keypad that's electronically and aesthetically compatible with the Apple II Personal Computer So you can enter numeric data faster than ever before.
The Apple Numeric Key- pad II has a standard calculator- style layout. Appropriate,
because unlike some other key- pads, it can actually function as a calculator
The four function keys to the left of the numeric pad should be of special interest to people who use VisiCalc." Because they let you zip around your work sheet more easily than ever, adding and deleting entries.
With one hand tied be- hind your back.
ViiiGik 14 a rt*i;iH(.*rcd trademark uf VisiCtirp. Inc.
microprocessor used in the IBM Personal Computer provides a 20-bit address which can directly address one megabyte of meinon/ (2-^ = 1048576).
The Commodore 64 has 64K of memory. BASIC ROM takes up part of this space, and quite a bit of RAM is used by the computer for pointers, screen memory, sprites, etc. This is why only 38K is normally available to the user. (See COMPUTE!, October 1982, for a 64 memory map.) You can bank-switch the 64 by POKEing address 2 . POKE 1,6, for example, makes BASIC go away and the RAM "behind" it is available. The bottom three bits of address 1 are memory control bits and direct the computer's attention to the available alternatives. Of course, what takes control of the machine when BASIC is gone is up to you.
Eookfor an article on controlling the 64's "hidden" RAM in an upcoming COMPUTE!.
Commodore is not yet sure 'whether the P128 will be softioare compatible with the 64.
Can Atari Make Tapes For Other Computers?
It is rr>y understanding that the programmable tone generators in Atari also generate the baud rate and tones used for cassette recording. If this is so, it should be possible to save programs in Kansas City Standard or other two tone formats, making possible the use of Atari editing features to prepare cassette tapes for other computers. How can this be actually done?
Steven S. Coles
While the Kansas City standard cassette interface is in use by mam/ computers, it should be noted that it is far from a full standard. Most computers deviate from the original standard one way or another. One nearly u}\i- versal deviation is to operate at 1200 baud rather than the original 300 baud spec.
The Kansas City standard uses a frequency of 1200 Hz to indicate a "0" bit and a frequency of 2400 Hz to indicate a "1" bit. The frequency change is performed when the waveform crosses the zero voltage level. The actual data transfer is usually done through as USART, but it is quite pwssible to simulate this in software. At this point loe run into a brick wall: just about everybody saves the data on the cassette in their own way, so you will have to find out what method is used for the com- puter you wish to adapt to. If at this point you are still interested in giving it a go, I suggest you go down to your local library and drag out the April 1977 issue of BYTE. On page 40 you will find an excellent article by Carl Helmers on how to do it.
VIC Custom Characters
I recently added 8K to my VIC-20. This causes new locations in RAM to be assigned to the start
of BASIC, the screen area, and color control area.
There is a technique for using custom charac- ters on the 5K VIC-20 that involves moving down the end of the BASIC RAM working area from page 30 to page 28 and loading pages 29 and 30 with the custom characters. Every custom charac- ter program that I've seen uses this technique - POKE 56,28:CLR.
Both the screen RAM and custom character area must be located below page 30 in RAM to work. Unfortunately, with the 8K expansion (and without 3K) there is no space available below page 30. The obvious thing to do is to relocate the start of BASIC text from page 18 to page 30, since with 8K the top of RAM is page 64. This appears possi- ble by changing locations 44, 46, 48, and 50 from 18 to 30. Unfortunately, it doesn't work. The RUN command results in a Syntax Error and GO TO yields Syntax Error in statement 0. (LISTS do work though.)
This wordy prelude leads to my question: Is it possible to have custom characters {and alternate screens) with the 8K expansion (and without the 3K)? If yes, how?
Dick Gough
Several readers have inquired about this. Unfortunately, there is no known solution at this time. Several pro- grammers arc currently working on this problem and xve'Il publish the a)iszver as soon as it is solved.
A Time-saving Tip
I'd like to share a trick I learned from the pro- grammers who did our business software.
Make the first line in your program a REMark statement containing your SAVE command. For example:
10 REM SAVE 6, 'iNVENTORY",D80
or
1 REM SAVE "INVENTORY",!.!
Then, whenever you make a change you don't have to remember where and how to save your program. Just LIST the first line, blank out everything before the SAVE command, and execute. It works equally well with tape or diskette.
Linda Johnson
Atari's Right Cartridge
Aside from "Monkey Wrench" [a programmer's aid package from Eastern House Software], does anyone know of any cartridge that goes into the right slot on the Atari 800? Does Atari have any
14 COMPUn! Jonuarv.1983
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plans to ever utilize this slot, or was it an idea that didn't pan out?
Bill Lukeroth
Tlje problem loith the right slot is that the Atari 400 doesn't have one. Atari has cxudeiitly abandoned appli- cations for the right slot since such an application could not be used on the 400. Atari is conwiitted to supporting both machines equally. Also, because a full 16K can be put on the left cartridge, it alone is enough space for most applications.
Commodore Time
I have a VlC-2.0, On several occasions 1 have at- tempted to tally the amount of computer time utilized via the TI and Tl$ functions.
Could you explain first the purpose of TI? Can it be modified manually - set to zero? What does a printout of 1429292 mean? What is its re- lationship to realtime and TI$?
Secondly, is TI$ supported to count realtime? If so, can you explain why 6 hrs. 31 mins. would show up on TI$ as 063639?
Lastly, is there any way to maintain a cumula- tive tally on the svstem of aggregate "on-time"?
D. L. Branam
You can tell Commodore computer's special time vari- able, TI$, what time it is (or set it to zero so it can keep track of how long the system has been on) by treating it like an ordinary string variable. For example:
TI$ = "033000"
would let the computer know that it was 3:30. This can be done either from zoithin a program or by just typing it in from the keyboard in "direct mode." The string is arranged "HHMMSS" for the positions of hours, mi- nutes, and seconds. It ivill take ainjthing up to 240000 hours and must include all six numbers, even if a zero is in the first position as in the example above.
You can print out the time in a variety ofioays. Here's one:
?LEFT$ (TI$,2) "/" MID$ (TI$,3,2) "/" RIGHTS (TI$,2
or just: ?TI$
TI is the numeric clock variable. It is set to zero when power is first turned on or tohen you reset the clock: TI$= "000000". The number in TI is counting time in llbOths of a second. To sec TI:
10 ?"[HOMEr' TI: GOTO 10
Six hours 31 minutes should be 063100 when TI$ is printed out.
Atari Memory Expansion Problems?
I own an Atari 800 with 16K memory and am care- ful about the quality of products I buy for my com-
16 COMPUIil jQnuarv.1983
puter. There seems to be a rumor going around about the 32K RAM memory board made to fit the 800 model. I've heard that adding this board can cause errors to occur in the computer's per- formance. Please tell me if it's true and, if so, how or why it happens.
Allen Levy
We have heard of no problems related to the use of a 32K board on an Atari 800. These expa)isio)! boards are not manufactured by Atari, but rather />i/ third parly vendors. The requiremotts of an Atari board are fairly specific: they nuist not use too nntch power a)ui they have to be fast enough (200 ns. or better). We haven't heard, though, of problems relating to expanding mem- ory xoith these products.
INPUT That Puts Anything In
Here's an interesting Commodore input routine that I'd like to share with you. Ever notice that when you INPUT a string which has a comma or colon that the computer only takes in the part before the punctuation and then prints EXTRA IGNORED?
Here's how to get around it. Say you want to INPUT C$:
10 GOSUB1000:C?=B$
20 PRINTB?:END
1000 B$=""
1010 GETA5:IFA5=""THEN1010
1020 PRINTA$r
1030 IFA$=CHR$(13 )THEN RETURN: REM 13 MEANS THE
RETURN KEY WAS TYPED 1040 B$=B?+A$ 1050 GOTO 1010
When you run this, you don't get the normal question mark. Now you can put in anything you want, but don't use AS or B$ any place except in this subroutine. Whenever you want to put in a string, GOSUB to 1000 and, when you come back with RETURN, just let the string you're looking for (C$ in this example) be equal to B$.
George Trepal
This INPUT routine is great for people zvho will want to use a computer prograju, but don't know about avoid- ing commas, etc. Whatever they type, the program loill take it in ivithout stopping and going to an error message and then saying READY. It's also possible to use delete and insert to correct errors (hut these "characters" will be included in the final string).
To prove it, run this and type TEST the first time. Then, when the program emis, type: ?LEN(BS) to see how long B$ is. You will get four as theansxocr. Now run it again and type TESX and then use the delete key to change the X back to a T. ?LEN(B$) will nozv give you a six because B$ still co)itains the X and a character for a delete. You don't )wtice these extra characters, though, because ivhen B$ is PRINTed, it puts the X on the screen and then deletes X, replacing it with T. It's too quick to see. ^
HOW TO IMAKE YOUR VIC-20
\ f ?
Right out of the box, your VIC-20* from Commodore is one great little computer. And it gets even better with DATA 20 's easy to buy, easy to install, and easy to use enhancements. Here are four ways you can get new power and more sophisticated capabilities from your VIC, . .
VIDEO PAK gives you a computer that outper- forms systems costing twice as much. Plug our car- tridge into your expansion port, and your display instantly goes to the industry-standard 24 lines, with a choice of 40 or 80 upper and lower-case characters. At the same time, you up your memory from 5K to 20K or 70K, so you can handle more sophisticated functions— including most 8032 software. Our pack- age also includes a terminal emulator and a screen print feature. VIDEO PAK is a must for word processing— and your key to increased performance on everything from games to spread sheets. Suggested retail is just $299.95 including 16K— or $399.95 for 64K.
PRINTER INTERFACE is simple, yet sophisti- cated. Flexibihty, continuous visual monitoring of the data transfer functions, and easy installation make this an exceptionally smart buy! A glance at the sta- tus Ughts, and you know if the printer is hooked up, if the data buffer is full, and if data is being transmitted.
Expansion Chassis
EasUy configured DIP switches match your VIC-20 to most popular printers. The DATA 20 interface comes with cable and connector, needs no assembly, and virtually troubleshoots installation for you. Suggested retail: S69.95 EXPANSION CHASSIS lets you use 4 cartridges at once. Run a series of compatible memory, software, or game cartridges of any make. Just pop in any car- tridge with the standard 22-pin edge connector. And don't worry about your VIC-20 power supply— our chassis protects it with a built-in 500ma fuse. Suggested retail: $64.95
MEMORY CARTRIDGE boosts your brainpower to 20K. Here's an ideal first add-on for your VIC-20. And when DATA 20 gives you more memory, you can forget about headaches. Our cartridge is housed in a rugged plastic case and features 200ns RAM's for reliability Suggested retail: S99.95
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Questions Beginners Ask
Tom R Halfhill, Feotures Editor
Are you thinking about buying a computer for the first time, but don't knoiv am/tliiiig about computers? Or maybe you just purchased a computer and are still baffled by what personal computing is all about. Starting this month, COMPUTE! will tackle some questions which xvc are most frequently asked by beginners.
of computer were dearly superior, and if we at COMPUTE! were in a position to know about it, then it stands to reason that all of our editors would own that computer. But in fact, both at work and at home, we own and use many different computers. 'Nuff said?
Q: Which is the best computer to buy? Al The best one for your needs.
Seritiusly, we're not trying to duck the ques- tion. People ask us this all the time, in letters, telephone calls, and at computer shows we attend. We get the feeling thev are never really satisfied with our answers, since what they really want to hear is something like, "Buy the Atapple ZX-20, it's definitely the best one." Unfortunately, we cannot give such an answer. For one thing, since COMPUTE! covers many machines, the magazine must maintain objectivity. But more importantly, there is no one right answer. All the computers have their own strengths and weaknesses, and all computer buyers have - or should have - their own ideas of what they need in a computer. We think nearly anybody who buys one of the major brands with a clear idea of his or her needs will be satisified with the purchase.
The key is to identify your needs and desires. If game-playing will be a major use of your com- puter, then color graphics and sound will be im- portant features. Someone primarily interested in word processing may well have no need for either feature.
If you've looked hard and long at the various computers in a certain price range and still can't decide between them, then perhaps the differ- ences are too slight to matter anyway. Or maybe you should base your decision not on the hardware, but on the available software. If the computer will be used primarily for educational purposes, and you're attracted by a particular line of educational programs, you may lean toward • the computer that those programs are designed to work on. The programs may not be compatible with or available for another machine.
If you still think we are sidestepping the whole question, then consider this: If one brand
18 COMPUTI! January. 1983
Q: What are PEEK and POKE?
A! PEEK and POKE are words (instructions to the computer to do something for you) in a computer programming language known as BASIC (Begin- ner's All-purpose Symbolic Instruction Code). BASIC is the standard language on home/personal computers. PEEK and POKE allow you, as a programmer, to work directly with the computer's memory.
PEEK allows you to examine the contents of a single memory location (known as a "byte"). Each memory location in a computer has a num- bered address, sort of like houses in a city. In turn, each memory location stores a number which usually has something to do with the operation of the computer or a computer program. If you type PRINT PEEK (8502), the computer will PRINT on the screen the number stored in that address. Therefore, PEEK is often used in programs to determine if a certain number is stored at a par- ticular location, usually as a prelude to changing the number to achieve some desired result.
POKE is the word that allows you to make those changes, to change numbers stored in loca- tions in Random Access Memory (RAM) - that part of a computer's "user memory" which can be changed by the programmer. For example, if you type POKE 82,0, the number 0 will be stored at memory location 82. POKEs can often change some facet of the computer's behavior. Since each model's memory is arranged differently, PEEKs and POKEs will not achieve the same results on different computers (in the above example, POKE 82,0 will make the left screen margin zero on an Atari).
Q: What is a CONTROL key?
A: A CONTROL key (often abbreviated CTRL) is
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Apple II IS a registered trademark ot Apple Computer, Inc. Atari Is a reglslereii Irademark ol Atari, lr)C.
a special key found on many computer keyboards. In effect, it works something like a SHIFT key. Just as a SHIFT key adds a function to a regular key - i.e., changes a lowercase letter to uppercase, or changes the "4" key to a dollar sign - the CON- TROL key also is used in combination with another key to select an additional function or symbol. These functions and symbols vary among different models of computers. For example, hold- ing down the CONTROL and "C" keys on an Apple II will usually stop (or "break") a BASIC program which is running. CONTROL-C on an Atari will print on the screen a small graphics character resembling the lower right corner of a box. On a Commodore VIC-20, CONTROL^C has no effect; another special kev is used instead to print graphics symbols. The manual which comes with every computer explains the functions of its special keys. ©
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Computers And Society
David D, Thornburg, Associate Editor
The Computer As A Tool For Discovery
The notion that the development of low-cost com- puters is "revolutionary" is not a new one, but the word revolutionary is used so much that one is likely to dismiss it as pure advertising hype along with words like "new" and "improved." And yet those of us who have been involved with this industry since its inception are aware that the development of the personal computer is not, by itself, revolutionary just because it may bring computer technology into people's homes.
"Revolutionary" is a special word - it implies that a technology or tool causes far-reaching changes in many aspects of our lives.
The development of the steam engine was revolutionary; the development of steam cleaning for carpets was not. The development of the tele- phone was revolutionary; the development of the answering machine was not. The development of the airplane was revolutionary; the development of in-flight entertainment was not.
Computer technology has had an impact that reaches far beyond the world of the computer itself. Computer users in industry and academia have known this for many years. Now that the power of the computer has reached the home, can we expect that people will start thinking about their world differently?
I think so.
The computer will help people to explore ideas that they wouldn't begin to explore if the computer hadn't given them the leverage to start thinking about them.
Beauty And Practicality
As an example of this, let's explore the develop- ment of a new field of mathematics called "fractal geometry." I have touched on this branch of mathematics in the "Friends of the Turtle" column a few times. I am intrigued by it because it deals with topics of considerable beauty and practical interest. Its seeds were planted a hundred years ago, but it was only after the development of the computer that anyone was able to begin to advance this field beyond the crudest level.
I realize the risk of illustrating a computer application based on mathemetics, since it tends to reinforce the erroneous concept that computers are primarily mathematicians' tools. The only
reason for pursuing this example is because it is an interesting story in its own right.
In the late 1800s mathematicians were ex- ploring some questions that went to the very foundations of geometry. One question of interest was if one could construct a curve that would fill a plane. At first thought, the idea of filling a two- dimensional surface with a curve made from a one-dimensional line is as absurd as asking for a roll of optically flat steel, or asking how many angels can dance on the head of a pin.
To the Italian mathematician Guiseppe Peano^ this was a most intriguing question. In 1890 he published a proof that space-filling curves were, in fact, possible - that one could construct a curve that has the dimension of a surface. While this proof attracted the attention of several other mathematicians, the bulk of the academic com- munity abhorred the thought of such "ill- behaved" curves.
In 1904 Helge von Koch continued the pursuit of strange types of functions by publishing the discovery of the "snowflake" curve. This curve is created by preparing successive generations from a simple motif. The rule to be followed is that each new generation is made by replacing each straight line in the previous generation with a copy of the motif itself.
Januorv.W63 COMPUTEI 21
If this process is carried on to infinity, one gets a very strange curve indeed. First, the curve is everywhere bumpy - there are no smooth re- gions. Second, even though the curve has clearly defined boundaries, it has infinite length. Third, the curve has a "dimension" that is intermediate between that of a line and a surface. To mathemati- cians of the early twentieth century, this curve was monstrous. To the contemporary mathemati- cian Benoit Mandelbrot, it represented the need for a new field of mathematics, to be called fractal geometry.
The history and development of this field is beautifully illustrated in Mandelbrot's new book. The Fractal Ceometiy of Nature (W. H. Freeman, San Francisco). Through the pages of this richly illustrated volume, the reader is treated to a new way of thinking about geometry and nature.
For example, if you want to model a coastline, you are far better off to use a fractal curve than a smooth approximation, simply because coastlines are not smooth. Coastal lengths depend on the ability of the measuring stick to follow the nooks and crannies along the way. A coarse measuring stick gives a result corresponding to an early gen- eration of a fractal curve. As the length of the measuring stick gets smaller, the total measured length of a coastline grows ever larger. This is also true for fractal curves.
Where does the computer fit in all of this? The notion of defining a curve in terms of itself may challenge the imagination, but it has a simple implementation in computer programming called recursion. Furthermore, the speed and accuracy with which computer-driven plotters can graph the various stages of curves free the mathematician to study their properties without being bogged down in drafting.
Computer graphics plays another pivotal role in the practical application of fractal geometry as well, since it is the tool that allows the creation of the simulated landscapes seen in movies such as Star Trek II. This practical application of a branch of mathematics would not have been possible
were it not for the computer.
Those of you who read "Friends of the Turtle" know that fractal curves can be created on home computer systems using turtle graphics. Their expression in languages such as Logo is quite simple, and Mandelbrot's book provides hundreds of challenges for the interested programmer.
It is important to keep the role of the computer in perspective. The reason that these curves were not explored in depth in the early 1900s is that there was no appropriate too! to aid in their ex- ploration. Now that the computer has made the study of fractals accessible to millions of people, one can expect the field to advance rapidly.
I Call It Kring
1 saw a T-shirt that carried the message: "Recur- sion is a way of expressing the infinite in finite guise." My friend Sam Savage (the computer scientist/mathematician that invented the jigsaw puzzle called "Shmuzzles") likes to play with the infinite recursively. While I have used Logo to tinker with the latest of his ideas, you may wish to implement them mechanically.
Consider The Kite
Your normal garden variety kite is on the end of a string that
droops gracefullv in an arc.
o
^^' This is fine for garden '^-— "^ variety kite fliers, but suppose A^ you wanted to make the string
/ \ straighter. One way to accomplish this would be to add a second kite in the middle \,
of the string. Because f^^^ each kite would carry '^^ less weight, they would each be smaller.
\.
But we still have some droop in the string, so we can add two more kites. •''■
o
f
\
And two more
A
/\
22 COMPUIH Jo™aiv.1'B3
If you're ready to learn intermediate BASIC programming
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On the other (hand, foot) if you didn't (grow with, thrill to. involve the whole family in) the PDI (learning, hands-on. fun ) experience, here's what you missed:
• Teaching techniques that teach ?
• Involvement you enjoy
• Sounds that spur you on
■ Graphics that simplify the complex
■ Animation that makes this tutorial a stimulating experience.
■ A friendly voice that guides you to course completion
The Step By Step Two program works this way:
• the computer program sets up screen displays or sample programs for you.
the cassette voice tells you what's happening, you (deal with, figure out. guess at) the answer. the computer (praises, pans) your work.
you (peruse, plunge into, practice in) the Work Book. after each lesson, you're (quizzed, queried, questioned). - you're then (prepared, practiced, primed) for the next lesson.
• the final exam reveals all (superstars, slackers).
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• Default values functions
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ASCII codes .RAMvsROM ■ hexidecimal numbers ■ machine monitor
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And so on, reducing the area of each kite and placing them closer and closer together.
If we keep repeating this process, we will end up with a substance I call kring- a combination kite/string that rises /
straight up in the air as it is ./
unfurled.
Now that's revolutionary!
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A space, adventure, and arcade action game L for your AEASI® 400/800'"" personal computer.
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Planetary adventures are designed to exercise your puzzle solving Intellect, with arcade action thrown in to enhance the excitement. Although you are given as much time as necessary to solve each adventure, your score, which Is based on many factors, favors those who are speedy.
After you capture all the treasures this universe has to offer, return to your adopted planet. Who knows, the gods may be so happy that you can convince them to send you back to jrour real home. You cant get there without their help!
Available from your local Atari retailer or send $29.95 in check or money order (California residents add 6V«% sales tax) to JV Software Inc.
Atari and 400/800 " are trademarks of AIARl, Inc.
A 32K assembly language
I »> ti»i j?rrt ,\i,\t ^%ni(-At%f»^
AEABI" 400/800 "computer.
J V 50FT\A/ARE , INC
3090 MARK AVE. SANTA CLARA, CA 95051
Tom R Halfhill, Features Editor
Synthesized computer musk is a recent development, but inventors have been working on "synthesizers" for decades. Today's home computers and microchips are now starting to open a neiv world of music and sound for everyone.
Hal Chamberlin, a leading authority on com- puterized music, remembers the days when ad- venturesome programmers used transistor radios and even line printers to squeeze music from their early computers.
"People used to tune a little AM radio to an open frequency and hold it next to their spacebars and listen to the sound of [program] loops/' recalls Chamberlin, vice president of engineering for Micro Technology Unlimited in Raleigh, North Carolina.
The method worked because pulses flowing through the computer's logic circuits would emit radio frequencies which "leaked" from the com- puter into the radio's receiver. The programmers on these early IBMs - fiddling around when the boss wasn't looking - soon learned they could play different notes and tones by writing little machine language programs with carefully timed loops.
"They even used to make music by 'playing' the printer," says Chamberlin. "They found out they could control the little hammers in the print- head with a machine language program. So they wrote programs to fire the printhead hammers in a certain pattern to create rhythms.
"Of course," he adds, "it wasn't so great on the printheads."
Such experiments seem crude, even quaint, in this day of computerized music synthesis and home computers with built-in, multiple-voice sound synthesizers on a chip. But these early efforts illustrate that today's "modern" sound devices are really the result of years of research, inventing, and just plain fooling around.
In fact, people have been working on sound synthesizers since the 19th century. And although today's computerized synthesizers seem incredi- bly advanced in comparison, the leading ex- perimenters in the field believe electronic music is only starting to make itself heard.
26 COMPUTEI Jcnuar¥.lP83
Telharmoniums, Theremins, And RhythmJcons
The first music "synthesizer" was built between 1896 and 1906 by American inventor Thaddeus Cahill. Hecalledita "Telharmonium."TheTelhar- monium is to modern synthesizers what ENIAC is to modern computers. The Telharmonium weighed more than 200 tons, and moving it to New York from Cahill's lab required several rail- road fla tears.
Since the Telharmonium was a pre-electronic instrument, it functioned by means of electric drive motors, pulleys, belts, and gears. Yet it was similar in basic concept to today's synthesizers. It was polyphonic (as opposed to monophonic), mean- ing it could play more than one note at a time and thus create chords. It was equipped with a stan- dard music keyboard, but the controls were so complicated that it took two people to play the thing.
The loudspeakers worked mechanically, and the machinery required to generate enough cur- rent to drive the speakers was so noisy that part of the Telharmonium had to be housed separately from the listening room. Unfortunately, after ten years of Cahill's work, the Telharmonium was a commercial failure.
For one thing, it was obsolete soon after it was finished. The diode tube was invented in 1904, followed by the triode tube in 1915, which made electronic amplifiers possible. It wasn't long before tube-powered electronic instruments began appearing.
The most successful of these was an instru- ment invented between 1920 and 1924 by Leon Theremin, originally called an "Etherophone" or "Thereminovox" but now known simply as a "Theremin." This odd instrument was played without being touched - the musician passed his or her hands through the air near two antennas which controlled the pitch and volume. To say the least, this made a Theremin very hard to play, since there were no pre-defined notes like the keys on a piano or the frets on a guitar. Still, There- mins became popular in the late 1920s.
Leon Theremin invented another electronic instrument in 1931 - the "Rhythmicon," the first electronic rhythm instrument. The Rhythmicon was quite sophisticated with features which have appeared on rhythm synthesizers only recently.
5
That^ why Apples and Ataris are saying: B "Talk Is Cheap"
PrS CALLED
THE SOFTWARE AUTOMATIC MOUTH,
S.A.M. FOR SHORT
Its a high quality speech synthesizer entirely in software. You use it as a software utility, load it inio RAful. and then use your machine as usual, except now you can make your pro- grams talk. It generates the speech sounds on demand, so there is no limi! to what it can say.
When you hear S.A.M., you'll prob- ably agree that it sounds better than all the hardware speech synthesizers for Apple or Atari computers. And. it has a truly remarkable price.
VOU CONTROL INFLECTION. PITCH AND SPEED
With its user-vanable inflection. S.A.I*/1. can accent words on the nght syllable and emphasize Ihe important words in a sentence.
You can also make S.A.fVl.s speech higher or iower. and faster or sfower. over a wide range of settings.
USE EASY PHONETIC INPUT OR PLAIN ENGLISH TEXT
S.A.M. understands a simple phonetic spelling system, not a mysterious alpha-numeric code. S.A.M. helps you learn phonetic spelling by showing you your mistakes, and the owner's manual gets you started with an English-to- phonetics dictionary ol 1500 words. So its easy to make S.A.M. produce exactly the sounds you ^p^
want, ^^ M
But suppose you ^^ Mi
want to type ordinary ^^'
English, or you want h,— ,— - , ^ your machine to read a word processor file aloud. The S.A.M. disk comes with RECI- ; TER, an Englisti lexl- to-speech conversion program that lets S.A.M- speak from . plain English text.
SAM
ADD SPEECH TO YOUR PROGRAMS WITH EASE In a BASIC program, you add speech with just a couple of commands. In a machine language program, its just as easy S.A.M. comes with four demon- stration programs to show off its dis- tinctive leatures and help to write your own talking programs. Write adventure games with talking characters, educa- _. ^ tional programs that
njl explain aloud, or
I JYVi utililies with spoken
prompts - put your imagination to work.
. S-AuB
You can order S,A.M. directly from DON'T ASK. Add $2.00 for shipping and haridling to your check or money order (or order C.O.D.)
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Requires 48K. disk. (S.A.M. takes up to 9K; RECITER 6K.) You will also need a speaker.
S.A.M. for the Atari 400/800 S.A.M. talks through yoi" •-'-■•■-■ —
speaker. No additional .
required. Only SS9.95 Requires 32K, disk. (S.A.M. takes up 9K: RECITER 6K.) Note: to produce the highest quality speech, S.A,M. automatically blanks the screen during vocal output; the display is preserved, S.A.M. can talk with the screen on, but the speech quality is reduced.
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THE 4(M) VIDE
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O CARTRIDGES
Quantum Data, Inc. (QDI) produces two (2) 40/80 Video cartridges, the 40/80 Video Combo Cartridge with 16K basic user memory, and the 40/80 Video Cartridge which does not contain memory.
The 40/80 Video Cartridge and Video Combo Cartridge is the means to upgrade the VlC-20 computer to a 40 x 24 or an 80 x 24 character display which provides a wealth of new uses for the VlC-20. With the appropriate software, you can now accomplish quality word processing and various business functions that previously were very difficult to achieve with only the VIC's standard 22 character video display.
• Features a high quality 8x8 dot matrix
• Character-by-character reverse video attributes allowing adjacent charac- ters to have different attributes.
• Black & White composite video (6545 controller does not support color). The Black & White composite video output has the same connector as the VIC video output, 5 pin DIN jack.
• Includes two character sets: The ANSI standard 7-bit character set and the Commodore character set. The ASCII character set features all of the standard lower-case and upper-case letters, symbols and numbers. The character set is contained in a standard 2716 EPROM. It is used most often to allow the 40/80 column cartridge to display all of the Block Graphics supported by the VlC-20.
• Cannot be used with abbreviated commands nor does it support multiple line wrap around.
• Operates in VlC-20 Block Graphic mode.
• Features lower-case dot descenders.
• All features are accessible through BASIC using POKE commands (screen memory resides at $B800 through $BFFF}.
• Contains 2K of CMOS internal video RAM; no system RAM is used by the Video Cartridge.
• Plugs directly into the VIC~20 memory expansion port or a Mini-Mother or Maxi-Mother board.
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The 40 character mode may be easily viewed on most standard TV sets but a monitor is required for the 80 column mode to provide the necessary addi- tional resolution.
Video Combo *319^^ Video Cartridge ^2W^
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The most popular electronic instrument of the past half-century was invented in 1935 bv Laurens Hammond - the Hammond organ, still widely used.
But although these devices were electronic instnniiciits, music historians trace the origin of electronic music back to Paris in 1947-48. Acoustical engineer Pierre Schaeffer and composer Pierre Henry began experimenting with new sounds by using electronic filtering, speed changes on tape recorders, and other manipulation tricks done in studios. Their technique became known as uiiisique concrete, and was quickly picked up by tinkerers elsewhere. By 1952, the first concert of electronic music was sponsored by Columbia University at the New York Museum of Modern Art.
The problem with these techniques was that it took many hours of tedious tape splicing and other tricks to produce only a few brief minutes of sound. And musicians couldn't even hear the results until they were done. That's why there was a lot of interest during the late '50s and early '60s in instruments which could produce electronic music directly. Even the old Theremins from the '20s- updated with transistors- were resurrected.
Toward A New Form Of Music
Robert A. Moog - whose name is virtually synonymous with sound synthesis- was selling kits for transistorized Theremins in the early '60s when he was inspired to invent his own electronic instrument. The result was the Moog Synthesizer, first built in the summer of 1964.
Although recognized by electronic musicians as an important development, the Moog Synthe- sizer was practically unknown to the general pub- lic until a few years later, when it was featured on a record album entitled Sivitched-On Bach. The album was a collection of Bach compositions per- formed entirely on a Moog Synthesizer by musi- cian Walter Carlos. Almost instantly, Sivitclmi-On Bach catapulted up the charts like a pop record, and became the biggest-selling classical record of all time. It was especially popular with teen-agers, who astounded their parents by playing electronic Bach along with their Beatles and Rolling Stones records.
However, a few classical music devotees, stunned by the album's popularity, dismissed the electronic interpretations as "artificial." Some critics, although they are decreasing in number, argue that music which is synthesized by purely electronic means is somehow artificial or unnatural when compared to conventional instruments.
Today, Moog counters these arguments with: "The fact is, vou don't find musical instruments in nature. The onlv 'natural' musical instrument is a human voice. The fact that a synthesizer pro- duces its music by electronic means doesn't mean
30 COMPUTl[ J<inijarv,1<?83
it's 'artificial' in any sense. It's no more artificial than taking a bunch of wood and gluing it together into a box and stretching some strings over it to produce sounds."
Electronic musicians, of course, never had any doubt that their instruments deserved equal billing with violins and woodwinds. In fact, years ago they recognized synthesizers as a rare histori- cal opportunity to open a new world in music. Although synthesizers are often used to mimic "conventional" instruments, the most exciting electronic music takes advantage of the synthe- sizer's power to create totally new sounds. This provides the possibility of entirely new forms of music.
For example, would rock 'n' roll have hap- pened without electric guitars? Did the invention of a musical instrument with a totally fresh sound spur the rise of a new genre of music? For the members of a whole generation, rock has become the dominant musical style. Synthesizers are now used in virtually every form of music, but even Moog isn't sure if they will "liberate" themselves and spark a new form which could replace rock. "Musicians are moving in so many different di- rections these days that it's hard to say if a new musical form will emerge."
It may be too early yet for the birth of a dominant musical form based on synthesizers, since the instruments themselves are changing so rapidly. Not only are they advancing technologi- cally almost day by day, but the rising use of micro- chips is just beginning to make them affordable for everyone. To return to the rock 'n' roll analogy, it would have been difficult for the teen-age groups of the '50s and '60s to arise if electric guitars had cost thousands of dollars. Or if radical new ad- vances were constantly rendering threc-year-cild guitars obsolete.
Synthesizers, on the other hand, are still pas- sing through important phases in their develop- ment. Moog foresees a trend away from analog sound synthesis to digital, or at least to digitally controlled analog instruments. "There's so much more you can do with digital sound synthesis, especially in small keyboard instruments like the little Casios or Yamahas you can buy very inexpensively."
About a year ago, Moog set up a new com- pany - Big Briar, Inc. - and relocated to a small town in rural North Carolina to work on such developments. Among his frequently used tools, he says, is an Apple II microcomputer. Mindful of the baffling array of controls on modern synthe- sizers, he's experimenting with new types of con- trol devices aimed at making synthesizers easier to play. But he warns that the complex instruments will never be a cinch.
"Musical instruments will never be easy to
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play," he says. "If it's too easy to play, most musi- cians would say it's not a musical instrument, because you usually can't do much with an in- strument that's 'easy to play.' It has too many limitations."
Still, as synthesizers get easier to manage and less expensive, they become more accessible to the average musician - and thereby more widely heard and appreciated by music listeners. Pop music historians may recognize this trend as the same sort of breeding ground for rock created by 45 rpm records in the '50s.
SID: Synthesizer On A Chip
One important way in which synthesizers are becoming accessible to people is within home computers. Virtually every new model introduced in recent years has featured more sophisticated sound capabilities.
• Unfortunately, up to now, the sound capabilities have attracted less attention than the often more glamorous feature; graphics.
"Well, in terms of the human senses, sound inherently takes a backseat to sight," notes Frank Covitz, a New Jersey research scientist whose sideline is computer music. "Sight is the more important sense, so computer graphics naturally gets more attention."
For instance, very little has been written on the Atari computer's sound capabilities, although the built-in four-voice sound chip has represented the state-of-the-art in home computers for the last couple of years. Almost all the attention has been focused on the Atari's graphics. Perhaps this will change now that a computer with even more ad- vanced sound has appeared on the market - the Commodore 64 with its SID {Sound Interface De- vice) chip.
The new SID chip is generating lots of interest among computer music enthusiasts. It may well be a herald of the sound capabilities of tomorrow's home computers. "I think machines of that class [home computers such as the 64] in the future will be expected to have sound chips, just as they are expected to have the BASIC built into them now," says Chamberlin, the MTU engineer. "For one thing, the sound chips are relatively cheap in large quantities, so there's no real reason not to."
SID is a hybrid digital/analog device with programmable attack, decay, sustain, and release for each of its three voices, a master volume con- trol, a choice of four waveforms, 16-bit frequency resolution over a nine-octave range, and pro- grammable high-, low-, band-, and notch-pass filters.
"The SID chip is basically a synthesizer on a chip," says its designer. Bob Yannes. "I played with synthesizers for years, so I'm quite familiar with them. I tried to put it all on a chip with the
32 COMPUni JariLiaiy.19S3
SID chip."
Yannes designed SID while an engineer for MOS Technology, which is owned by Commo- dore. He recently left Commodore to form his own company. Peripheral Visions, Inc. Although he won't say for sure what new products his com- pany will introduce, it seems likely that com- puterized sound devices will be among them. He says chips such as SID are the key.
"There's no reason we can't take music sys- tems being sold now for $4000 and bring them out for consumers for around $400 or $500 - a ten to one cost reduction. 1 consider the [Commodore] 64 to be only the first step. In the future I'd like to see something totally digital. I think that's the way to go.... I pretty much got the features that I wanted out of the SID chip in the 64, but not the performance I wanted. But now that I've done it once, I think I have a better idea about how to go about it next time."
Yannes says he was given specifications by Commodore only to develop a "sound chip," and then he decided to make it as much like a synthe- sizer as possible. But he had to work within the limitations of marketing considerations. For ex- ample, although SID allows each voice's envelope to be individually programmed, all three voices share the same volume control.
"I had to put separate envelope controls for each oscillator [voice] into the SID chip in order to satisfy the video game/sound effects marketing demands, if I had my way, the three oscillators would work in unison to create one voice. Any- way, that's why there' re separate envelope con- trols for each oscillator but only one peak amplitude [volume] control - it was designed to function as one voice. You could varv the attack of the different oscillators, for example, to get a ■brassy sort of sound that way."
But Yannes bestowed SID with yet another feature to compensate for this limitation - an input line. It's possible to feed an outside sound source into a computer equipped with SID, process it through the chip's filters and volume controls, and output the extra source as a "fourth voice" in accompaniment with SID's regular three voices. In the case of the Commodore 64, for instance, the outside source would be routed through the RF modulator to the TV speaker or a stereo system.
What kind of outside sources can be fed into SID? "You name it," says Yannes. "Tape re- corders, radios, electric guitars, even another SID
chip."
Note that last item: another SID chip. "One thing I thought you might be able to do is chain a bunch of SID chips together to get even better sound, without having to use external hardware," explains Yannes. "I designed the SID chip as a
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From "Tlie Editor's Feedback" Card, a monthly part of our contimjlng dialogue with, readers of COMPUTE!. These are responses to the question,
"Wliat do you like best about COMPUTE! ?"
l."It is written so a beginner can read and understand it... it's layman oriented..." 8. "Clear, clean layout, good presentation..." 3. "The Atari game programs..." 4. "Best and most information on PET..." 5. "Cover to cover, ajid all in between..." 6."Beviews of software and hardware.. " 7. "Good balance of application and technical articles..." 8."It is the best source of info about various levels of VIC/PET/CBM machines and ap- pUcations..." 9. "The BASIC and machine language programs..." 10. "I like programs that can be typed into a computer, run, and then used right away ( a program without bugs!)..." 11, "That it is organized well, and covers abroad range of information con- cerning Atari. Keep it up! please, I'm learning..." 18. "Table of contents listings and computer guide to articles is a great idea. Best magazine for personal home computer users..." 13. "Best I have foxmd for VIC info..." 14, "Informative articles: 'Secrets of Atari', Gam,e programs, especially programs that teach the reader about the Atari..." 15. "I like all the articles and programs for my computer, the PET. I've learned and found out things about it that I never even thought existed. Other magazines don't have too much material for the PET and, for that reason, I ftad COMPUTE! invaluable..." 16."The up-to-date hardware reviews..." 17. "Macliine language utilities for Atari..." 18." Articles are terse but understandable and accurate. Utility and applications pro- gram listings very helpful..." 19."The April, '82 issue is my first. I am impressed that you not only acknowledge the VIC-20, you even have applications for it..." 20."I really enjoy (since I am one) the Beginner's Page..." 81, "The attention it gives to Atari and the easy-to-understand language it's written in..." 88. "It is concerned with ex- plaining programs, not just listing them. It is the best VIC magazine I could buy..." 83."The new table of contents 'Guide to Articles and Programs' is excellent, particu- larly the indication of 'multiple computer' items..." 84."Broad range (sophistication) of programs..." 85. "You don't speak over the average user's head..."
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standard 6502 peripheral chip with all the proper bus signals. You could put some SID chips in a cartridge and plug it into the 64, or the VIC-20, or the Atari - any 6502, 6809, or even 68000 system, even the Radio Shack Color Computer. It only requires 32 address locations, and the chips are pretty cheap, so there's not much to stop you."
It's an exciting prospect, but Commodore controls the SID chip, not Yannes. And for now. Commodore needs virtually all the SID chips it can make to meet demand for the new 64, plus the upcoming Max Machine, P Series, B Series, and BX Series computers soon to hit the market.
Still, a few SID chips have reached private hands, and the results are fulfilling their creator's hopes.
The Synthesizers Of Tomorrow
Chamberlin, the MTU engineer, got four SID chips from his friend, Yannes. Chamberlin used them to make a prototype sound board for the MTU-130, a high-end personal computer for which he de- signed most of the circuitry. He then passed the board and SID chips along to another friend, Frank Covitz, the New Jersey research scientist. Covitz added four more SID chips to the board, for a total of 24 individually programmable voices. The board is plugged into an MTU-130 equipped with an organ keyboard which, in turn, is controlled by its own 6502 microprocessor.
The instrument made its first public appear- ance recently when Covitz's son, Philip, gave a performance at the Personal Computer in the Arts Festival in Philadelphia.
Ironically, Covitz says he didn't play his own invention at the festival because he's not a good enough musician. But he's working on software which not only will exploit the instrument's souped-up capabilities, but which also will make it playable by mediocre musicians. This is called non-rciiUh)ie playing.
Musical instruments are usually played in what's known as realtime: the music is heard in- stantaneously as the musician plays the instru- ment. When an instrument is played in non- realtime, the keying of notes is a separate event from the playing of the music. Notes are entered (the computer instrument is programmed), and then played back (the program is run).
An example of this on home computers is the Atari Musk Composer cartridge. Essentially, it does for music composition what word processing does for writing. Notes are entered on the computer keyboard and plotted on staffs drawn on the screen. The notes, measures, and phrases can be edited and arranged at will, then played back at the touch of a key. Similar composition programs are available for other personal computers.
"One of the things that computers can do is
34 COMPUIB Joriuarv.1933
change music from a physical endeavor to a pro- gramming endeavor," says Chamberlin. "That's one of the reasons why I got into computer music - my total lack of dexterity. Even if you're a total butterfingers like me, you can experiment with computer music."
Covitz is striving to push the concept even further. He's added four special keys to his pro- totype board: Record, Play, Fast Forward, and Rewind. But don't mistake it for a conventional tape recorder -the keys are similar in function, but not in method.
When the Record button is pressed, the com- puter will "remember" whatever music is played. But no recording tape is involved. Instead, each keypress on the organ keyboard generates infor- mation coded in four bytes: which key was pressed, the velocity (how hard the note was played), and the exact moment the key was pressed, accurate to a split-second. Another four bytes of information are generated when the key is released, for a total of eight bytes per note. All this information is stored in memory so the music can be reconstructed later.
After a musical part is "recorded," the Play button can be used to play it back - in accompani- ment with a matching musical part played by the musician on the organ kej'board. And this duet, in turn, can be "recorded" in memory by a second unit. Using just two of these "memory recorders," the process can be repeated again and again, lay- ering sound upon sound.
While the same thing can be done with con- ventional tape recorders, the sound would de- teriorate with each generation of re-recording. Tape hiss and other defects would soon overcome the music. But since Covitz's instrument "records" the sound digitally, there is no degradation what- soever. Beyond that, the music can be "edited." If a note is missed, the musician can correct it by rewriting the correct values into memory.
"This is what I see as the ultimate system," says Covitz. "Right now, this software doesn't exist anywhere except in my mind. I'm in the process of working on this now, and it's all being done in machine language."
The brief history of home computing - and indeed, home computing itself- indicates that advanced technology eventually works its way down to the personal level. It's not hard to envi- sion the day when plug-in organ keyboards and cartridges with add-on synthesizer chips will transform home computers into the kind of in- struments Covitz is experimenting with now.
"Seeing what the SID chip can do, and do digitally, I expect you'll see an explosion of that sort of thing," says Covitz. "There has to be. It doesn't require very much hardware. There defi- nitely will be an explosion in complexity." ©
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Parti:
Writing Transportabie
BASIC
Edward T Ordmon
Department of Mathematical Sciences
Memphis State University
Ifi/ou thi>ik your programs might ever he used on another computer with a different dialed of BASIC ■ the suggestions in this tioo-pari article can go a long way towards easing the transition. This month the author covers documentation, vocabulary, and reada- bility. The article concludes next month with an over- view of highly machine-sensitive issues such as input- output and graphics.
So you finally got your own computer. Unfortu- nately, it is not the same model you had at school. Or you've arrived at high school or college and the computer there is not the same one that your junior high school or high school had. What are you going to do u'ith all the programs you have accumulated? My own school has just bought several of the new IBM Persona! Computers - but most of the programs we have on hand were writ- ten for a mainframe or for our OSl microcom- puters. Come to think of it, we are changing main- frames next semester, too!
Of course, all of these machines have a version of BASIC. (Some of them, in fact, have several versions of BASIC.) But, as is clear to anyone who has read a program written in Apple BASIC and wished he could run it on his Atari (or PET or TRS-80 or ...), all BASIC interpreters are not the same.
What is the solution? There is no ideal solu- tion, for all cases. Some published programs are difficult to convert from one dialect to another. We can, however, in writing programs for our- selves, for friends, and perhaps even for publica- tion, try to make our programs transportable. That is, we can write the programs so that they can be adapted to another machine with a minimum of difficulty.
Self-documenting
A program is easily transportable from one machine to another if it can be entered and run in the second machine with no substantial rewriting - certainly no changes in the underlying logic or
36 COMPUTE Jcmuatv.ivaa
algorithms - and a minimum of minor changes. The program should be self-explanatory so that it can be rewritten without knowledge of the original machine - a knowledge of the machine we are rewriting it for should be enough.
I have one fairly complex simulation program that was first written about 12 years ago for a PDP- 8. It has since been rewritten, by me or by others, for S-100 bus machines in CBASIC, Apple, TRS-80, IBM Personal Computers and IBM 370's, Xerox Sigma 9, PDP-11, and enough other machines that I have lost count. I suspect that it would have been forgotten after the second or third transpor- tation to a new machine, if it had not been written so that it was usually just a matter of typing it in again.
I should warn you at the outset that all this article considers is how to write the BASIC pro- gram. It does not address the problems of getting a program from one machine to another without having to key it in again. Increasingly, it is possible to connect the two computers over a phone line, directly or via one of the dial-up timesharing ser- vices, and move the program as a text file to avoid retyping. Nevertheless, the focus of this article is transportable programming techniques.
What can you do, when writing a program, to make it easily transportable? We will divide the strategy into five main parts: 1) minimal vocabu- lary; 2) in-program readability; 3) formal struc- turing; 4) careful attention to input-output; and 5) limited graphics.
Minimal Vocabulary
First, let's consider the question of vocabulary - what features of BASIC we should use. Appar- ently, whenever a company produces a new com- puter or a new version of BASIC, it feels compelled to add features not found in anyone else's BASIC. Often these features are convenient and may make programming for that machine easier. However, they make transporting a program much harder. If at all possible, such features should be avoided when writing with transportability in mind.
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If we must use special features, they should be isolated in a subroutine near the end of the program and clearly labelled. The main program should stick to features found in virtually all ver- sions of BASIC. This does not mean that string handling must be restricted to the limitations of Radio Shack Level 1 BASIC, which is an extreme example; nor are there universal rules as to what constructions are allowed. Some textbooks define "minimal BASIC" or restrict themselves in a similar way.
Educational institutions often belong to groups (consortia) which promote standards for exchanging programs; CONDUIT is one such educational group with a nice pamphlet on stan- dard BASIC. If you have worked with several versions of BASIC, sticking to common features is a good guide for what will be transportable be- tween them. For informal use, however, or for the individual who has just worked on one machine, here are the standards I have found useful in working with perhaps a dozen different machines, large and small.
Variables And Commands
Figure 1 suggests some guidelines for variable names, numbers, line numbers, DIM statements. Clearly, the list could be made much longer. For instance, how big can a real number be and not overflow? How small can a positive number be and still be distinguished from zero? Most BASIC programs do not depend critically on these figures, which may differ dramatically from one system to another.
Figure 1: Variables and Numbers
Line numbers: 1 to 9W9
Variable names: One letter or one letter and one digit. Strings, one letter and S. Examples: A B2 C9 F$ Z$
Dimensions: Always declared if needed; execute the DIM statement once, before using the variables. If posj.ible, stick to one subscript for strings, two for numbers. Do not use variable sizes or reuse letters. DIM C$(50),D(20,10) is good; DIM B(N), A(50),A$(20)isbad.
If your program does depend on them, you should probably make this explicit (and include a REMark giving the limits on your system). For instance, if your program has a variable X that gets closer and closer to zero as you go around a loop, and you exit the loop by testing IF X = 0 THEN . . . , the program may behave very differ- ently or even fail on another computer. Changing this to
will make the program transportable: the person converting it can check to see if the new computer will accept lE-50. If it will not, he can substitute an acceptable number, e.g., lE-30.
|
Figure 2: |
|
|
The most common statements |
|
|
DATA |
LET |
|
DIM |
NEXT |
|
END |
ON.. -GOTO |
|
FOR...TO,..STEP |
|
|
GOSUB |
READ |
|
GOTO |
RESTORE |
|
IF.. .THEN,., |
RETURN |
|
INPUT |
500 IF ABS(X)<lE-50 THEN , NON-ZERO NUMBER
REM USE A SMALL
Figure 2 shows a limited list of BASIC com- mands - a very limited list. While almost every BASIC accepts more commands than these, they differ on which statements those are. For each command not on this list, there is some computer around that will not accept it. To make matters worse, computers differ substantially in how they interpret some of these commands. Some, for instance, do strange things on a STOP but allow END only as the last line of a program. The cure: place 9999 END as the last line of the program, and terminate anywhere else by GOTO 9999.
GOTO and GOSUB should be followed just by a line number. GOTO 500 is fine; avoid GOTO A even if your computer likes it. In the statement FOR X = A TO B STEP C, it is best to restrict A, B, and C to integers (or expressions evaluating to integers) and to avoid changing them inside the loop. NEXT must name just one variable for the corresponding FOR, e.g., NEXT X.
IF... THEN statements require special atten- tion, since so many computers have so many dif- ferent extensions. A few computers accept only statements such as IF Y> =Z THEN 830, prohib- iting calculations, logical operations, and not al- lowing anything but a line number after THEN. I am not seriously suggesting that you keep things this simple: the extensions are extremely helpful. However, it is a good idea to keep things simple enough so that your statements can be translated into this form. This will be discussed further in the section on structure, next month.
Numeric And String Functions
Figure 3 shows the most commonly implemented numeric functions. Either most BASICs have these functions, or the programmer using the machine will be prepared to fake them somehow. Two deserve special mention: RND and TAB.
RND is implemented differently on almost every computer. Some use X = RND, some use
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|
Figure |
i 3: The most common |
|
|
numeric functions |
||
|
ABS |
cos |
INT |
|
RND |
SIN |
TAB |
|
ATN |
EXP |
LOG |
|
SGN |
SQR |
TAN |
X = RND(0), some use RND(l), some use RAN- DOMIZE to start (seed) the random number gen- erator and some do not. You should assume that every line containing RND will have to be rewrit- ten. You should make this as easy as possible, by minimizing the number of lines involved and making your intention clear. If you need a random number in 20 different places in your program, do not have RND appear in 20 places; place it in a subroutine. That is, incorporate in your program
9000 REM **t SET RANDOM NUMBER, CHANG e FOR OTHER COMPUTERS ***
9010 X=RND(1):REM R ANDDM , 0<: X < 1 , NEW S EDUENCE EACH RUN
9020 RETURN
and then place GOSUB 9000 wherever needed in your program. Here is a more typical use, near the start of a game program:
150 N = INT(100»RND) + 1 :REM RANDOM INTEGER
1 TO 100
H.*»**»lfr»*!*-**»»*
Here the string of asterisks warns you, when transporting the program, that the line is likely to change. The remark tells what is wanted and will save a lot of time if the new computer achieves thisbyN = RND(100).
Turning briefly to TAB : there are computers that like TAB(N) (go to column N), those that like SPC(N) (print N spaces), those that like both, and those that like neither. Most people know how to juggle spacing on their own machine, so making your intention clear (by remarks or a sample print- out) is probably more important than the exact way you write your PRINT statements. There will be more on this in the discussion of input-output, next month.
Figure 4: The most common string functions
ASC(X$) CHRS(N) VAL(X$) STR$(X)
LEFT$(A$,N)
RIGHT$(A$,N)
MID$(A$,I,))
The functions given in Figure 4 are now re- markably widespread in microcomputers. It is probably safe to use all of them freely in that con- text. That is, if the person rewriting the program
does not have LEFTS, he probably has a reasonbly direct substitute. You cannot count on the format produced by STR$ being the same from one machine to another - some pad with blanks on the left, some on the right, some not at all. Func- tions that match a substring are present on many machines, but absent on many others. Many sys- tems will crash if you call LEFT$(A$,N) and A$ has less than N characters, so you should always test for this before you call LEFT$ even if your system does not insist on it.
Large computers differ substantially in how they handle strings, and are often more restrictive than small computers. ASC and CHR$ are fre- quently absent; many large computers do not even use the ASCII character set. Avoid extensive string manipulations, or at least place them in a subroutine, if your program may have to run on a large mainframe next year.
Readability
Next, if our program is to be readily transportable to another version of BASIC, it must be readable. First, can the reader understand our individual lines, and translate them for the new system? Second, can the reader understand our general strategy or procedure (our algoritlim) well enough to debug the program if errors creep in, or if his BASIC interprets some command very differently than expected?
The most important consideration, for the second of these, is to make the program suffi- ciently modular and to provide appropriate REMarks for each module; this is addressed more in the discussion of structure, later. There are a number of "tricks of the trade" that make indi- vidual lines easier to read, however. Here are a few principles:
1. Leave plenty of space between line num- bers. Even if you have only one command per line, some one-line commands on your system may become multiple commands on another. If you use several commands per line, the situation gets far worse. This is not to condemn all multiple- command-per-line statements, since they can add to the clarity of the program. Just remember that while your computer may allow:
500 INPUT "WHAT IS YOUR NAME?"; N$
someone else's may require
500 PRINT "WHAT IS YOUR NAME";
501 INPUT N$
This is an easy change if you left a line number available. It is quite possible for a complex one-line statement on one system to require six or eight lines on another.
2. Leave plenty of blanks in your commands, where appropriate. You may have no trouble understanding 250PRINTT5 or 300FORI5 = PTOM
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but n reader will find 250 PRINT T5 and 300 FOR L5 = P TO M much easier to copv or edit. Many BASICs do irisist on the spaces; the new IBM Per- sonal Computer is one that does. Your computer may allow a larger program or run faster if vou delete spaces and remarks, but you make the pro- gram much harder to transport when you delete them. It may be worth keeping two programs, a transportable copy and a condensed, quick-run copy.
3. Avoid unprintahk' characters. Where a few are necessary, find a way to make their presence visible. For instance, a disk read in Applesoft re- quires that you PRINT a CONTROL-D followed by a string. You can make this readable by
200 D$= CHR$(4) :REM CONTROL-D
540 PRINT D$;"OPEN FILENAME" :REM DOS COlVrMAND STARTS CTRL-D
It is a good idea to indicate what other CHR$ characters are when they are created, too - for instance when CHRS is used to put a quote mark into a string, or manipulate carriage returns or line feeds.
4. Identify specific features you depend on. This happens most often in connection with PRINT and INPUT statements. Most of us can guess what someone else's PRINT statements are supposed to do, but the INPUTs are another matter.
Some systems input a sentence like "TODAY IT RAINS" by INPUT A$ and the response 7TODAY IT RAINS; others bv INPUT A$ and response ?"TODAY IT RAINS"; others by INPUT LINE A$ or by LINPUT A$ or even by INPUT (FIELD 40) A$. You can make this clear to the reader - so that he can try to do the appropriate thing on his system - by remarks, but clear user instructions within the program are probably even better. For example,
110 PRINT "TYPE IN A SENTENCE SURROUNDED
BY QUOTE MARKS" 120 INPUT A$ :REM SAMPLE "HELLO, JOE,
WADDAYA KNOW."
5. Make cues to the user extremely clear. Re- member that you won't be around to show people how to use it; in fact, no expert on the program will be around. Give sample aiiswers whenever possible, and protect against invaUd answers.
130 PRINT"Da you WANT TO PLAY AGAIN (
Y/N) ■' ; 140 INPUT A« 150 IF AS="N" THEN 9999 160 IF A*<>"Y" THEN 130
Note that invalid answers will cause the question to be asked again.
Next month, cxniuples of portable pro;fnvn strucliiiv, input-output, and j^mphics pro;;;>wnuiing. ©
Mattel's New Home Computer
Tom R. Halfhill, Features Editor
Judging from the inquiries we've been receiving at COMPUTE!, people are having a tough time choosing between the current crop of low-end home computers: the Atari 400, Commodore VIC- 20, Radio Shack Color Computer, Sinclair/Timex, and Texas Instruments TI-99/4A.
Well, it's about to get even tougher.
Mattel Electronics has announced a home computer aimed squarely at the low-end market. It is jwt to be confused with the long-delayed Intellivision keyboard attachment - which has been redesigned again, incidentally. Mattel says the new computer, dubbed the Aquarius, is due "very early in 1983."
The Aquarius will sell for under $200 retail. The price is expected to vary because the machine will be sold through mass consumer outlets. This means it will be available at a wide range of TV- electronics stores, audio/video shops, department stores, discount stores, and catalog showrooms. As we've seen with the other low-end home com- puters being marketed this way, prices are greatly discounted because competition is so fierce.
Expands To 52K RAM And CP/M
The Aquarius will come with 4K of Random Access Memory (RAM), expandable to 52K RAM in 4K and 16K steps with plug-in cartridges. Microsoft BASIC is built-in. There is one voice for sound effects or music, and an expansion option (de- scribed below) provides three voices. The maximum graphics resolution is 320 by 200 pixels (screen dots) in 16 colors.
The Aquarius can display 256 characters. This includes a 128-character ASCII set with upper- and lowercase, and 128 user-programmable char- acters, similar to the redefinable character sets on the Atari, Commodore 64, VIC-2G, and TI-99/4A computers.
For the Central Processing Unit, the central "brain" of the computer, Mattel chose the Z-80A, an eight-bit microprocessor chip. The use of this chip allowed Mattel to give the Aquarius CP/M capability. CP/M (Control Program for Microcom- puters) is an operating system primarily used for
business applications. The Aquarius can run CP/M with the addition of a disk drive and disk controller card. It is very unusual that a low-end home com- puter would have CP/M capability, but a Mattel official explained, "Some home users will be pro- , fessionals who will prefer to work at home." With CP/M, a huge library of existing business programs will work on the Aquarius.
The keyboard has 49 keys. It's more than the membrane keyboard found on the Atari 400, but is not quite a full-stroke typewriter keyboard like the VIC-20's. The keystroke travel is 1.5 to 2 mil- limeters, and the keys are made of a rubber-like material instead of hard plastic, similar to the keys on Sinclair's new ZX Spectrum (see COM- PUTE!, August 1982). The keyboard accepts over- lays for special applications. For example, an over- lay for BASIC programming allows one-key entry of BASIC commands.
While all of these features are standard in the under-$200 Aquarius, Mattel says it will offer a complete system "in the $500 range" which will include a data recorder (tape drive), a printer, and the Aquarius Mini-Expander. The Mini-Ex- pander is an attachment which adds three-voice sound, two game controllers on eight-foot cords, and two slots for plug-in cartridges. One slot is for memory expansion and the other accepts car- tridge programs.
All of the software initially released for the Aquarius will be on cartridges. Mattel promises that eight to ten cartridges will be available when the Aquarius is introduced. This will include edu- cation, home management, personal improve- ment, and entertainment software.
One cartridge will be a low-cost Logo with turtle graphics, the acclaimed learning language for children. Mattel says its Logo is designed to work on a minimum system without extra acces- sories. Another cartridge will be FileForm, a word processor. Mattel says more cartridges will be released monthly after the computer is introduced, and that additional software may be available on cassette in the future. All the software has been developed at Mattel, although the company is now talking to outside developers.
Other expected add-ons include a disk drive and a 40-column thermal printer. No prices have been disclosed for these extras, but a Mattel official did say that the memory expansion boards would be "extremely price-competitive."
Apparently, the Aquarius will lack special function keys, sprite graphics, and full-screen editing. Reportedly, it will have 8K of ROM (Read Only Memory), a 40 by 24 screen display, dimen- sions of 13 by 6 by 2 inches, and weigh four pounds. It will come with simplified instruction cards so beginners can get the machine working without reading the manual. ©
Janua(Y,19e3 COMPUTS! 43
THE BEGINNER'S PAGE
Richard Monsfieid, Senior Editor
Myths About Programming
Whenever someone says that they are "not the type" or they "weren't good in math" as a reason for not learning to program in BASIC, I like to compare learning BASIC to learning how to drive a car. A few people never learn to drive, but most of us do. What's more, it takes a few weeks at most to catch on to either driving or BASIC. You. improve over the years, but the essentials can be grasped pretty quickly. And in the coming Age of Information, not knowing how to program could well be as inconvenient as not having a driver's license is today.
After all, there are only some 50 BASIC words to learn. Several of them are very rarely needed {you can look through hundreds of programs and never find WAIT, POS, or TAN). Also, many BASIC words mean exactly what they say: STOP stops a program, RUN runs, END ends.
If someone is still doubtful, the most con- vincing argument is a demonstration. You can say: "Let's try something complex. How about printing your name 1,000 times on the screen?" Then type: 10 ? "Alan"; : GOTO 10.
Could ft Explode?
Another factor which causes hesitation about learning programming is a fear of the unknown. It's not hard to see where this nervousness comes from. There is a category in movies which changes each generation, but could be called the Franken- stein Slot. A scientist gets too big for his britches, tampers with unknown forces, and his creation runs amok while the villagers, in their ancient wisdom, ineffectually stone the laboratory.
During the fifties there were dozens of films in which atomic radiation filled this slot. It caused moths and ants to grow to enormous size, ram- paging through cities. When people learned that radiation, dangerous as it can be, could not cause insect giantism, popular entertainment found a new monster. Dozens of movies in the sixties (some of them excellent, like 2001, The Farbin Pro- ject, and more recently. The Demon Seed) portrayed the computer as Frankenstein.
44 COMPUnt Januatv,19e3
When people buy their first personal com- puter, they are not generally worried that it might destroy their house, but they often worry about the computer getting out of their control and damaging itself. They sense, correctly, that a com- puter is a powerful machine.
You'll see this hesitancy when people look up, their first time in front of the keyboard, and ask, "What should I be careful of? Can I hurt it?" We get letters from beginners wanting to know if they should use POKE, the BASIC word- that changes what's in the computer's memory. They have a perfectly understandable fear that, as one New Yorker recently wrote, "I might damage the BASIC ROM chips. '^'
Your computer watches out for most kinds of
errors. It simply won't allow you to POKE into
BASIC ROM chips. If you try to send a POKE to
an address that's in ROM (Read Only Memon,'), it
will just bounce off. Nothing happens. These
addresses can only be read, not written (POKEd)
to.
We always used to say that nothing you could
type into the computer could hurt it in any way.
If it doesn't understand what you write, or can't
carry out your instructions, it will stop and tell
you where it stopped and, in general terms, why.
The worst that could happen would be an "endless
loop," and you would have to turn power off and
back on to get control. None of this, however,
would start the computer smoldering.
This advice, unfortunately, is not 100 percent correct. It was discovered that there was one POKE to PETs with Original or Upgrade BASIC versions which would make the video display about six times faster. It's POKE 59458,62. PET/CBMs with the most recent 4.0 BASIC chips, however, ca>i be damaged by this POKE if left running without turning off the power. Since there are about 17 million combinations of POKEs you can make into your computer, the odds are clearly against your accidentally making this error. Nevertheless, it does make it impossible to tell someone that nothing you type into any computer could hurt it.
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The Math Myth
When autos were first becoming popular, there were doubtless many people who refused to try driving, saving, "That's one thing that I will never try to learn. I could never control our horse." A weakness in math is often given as the reason for not trying programming. In fact, the two activities are hardly related. Mathematical words are avail- able in BASIC, but programming does not need to involve much math beyond simple arithmetic unless you choose to solve mathematical prob- lems. You will need to search a long time to find any use of the word SIN in the dozens of BASIC programs pubhshed each month in COMPUTE!.
Personal computers are general-purpose tools. They can be used to solve complex equa- tions, but to call programming "mathematical" would be too narrow it down to only one of its countless applications. And it would also mislead people into thinking that they need a special talent in math to become competent programmers.
Several years ago one of America's largest corporations undertook a study to find out what its best programmers had studied in college. To nearly everyone's surprise, English and music were the most common majors among the top computerists. Perhaps this is because these dis- ciplines stress creativity and attention to detail.
Perhaps they combine logical thinking with imag- ination. No one has yet given a satisfactory explanation.
In any case, you don't need to become an ace programmer any more than you need to drive at the Indianapolis 500. To get where you want to go, ordinary driving or programming knowledge will suffice. There are very few people who can't learn the necessary skills.
]f ihcre IS a topic Ihal you would like to see discussed in this column, send a card or letter to: The Beginner's Page, COMPUTE! M(7(,'(72»;f, P.O. Box 5406] Grceitshoro, JVC 27403. ' €
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Atari's Sound System
John Scarborough, Novato, CA
If you're interested m the improvements to Atari sound and music possible via machine language - this will get you started. These simple demonstrations might con- vince you to abandon the SOUND command entirely.
Many programmers who decide to make the jump from BASIC programming to machine language programming find frustration in their attempt to print to the screen or produce sound. The problem is that there are now no print or sound statements. Machine language deals entirely with retrieving, manipulating, and storing data.
But even after the programmer discovers this it won't do him much good unless he knows where and what to store to produce results. Furthermore, this information is often not provided in the man- uals that come with the computer. So how does he obtain this information? He must turn to other methods. Four common ones are:
1. The trial and error method (very inefficient, but sometimes necessary).
2. Advanced user's manuals.
3. Information obtained from a human source, such as from friends or teachers.
4. A magazine.
This article is in category four. After studying this article, you will have more control over the four voices provided by the Atari. The article will also briefly cover the built-in speaker.
Sound Commands
Look at the following sound command:
SOUND 0,121, X,X
This instructs the computer to store a value of 121, which will produce a middle C note, into Audio Frequency Control register 0. This register is located at memory location 53760 (SD200 hex). Thus, the following two commands will function identically:
SOUND 0,121,X,X POKE 53760,121
The three remaining Audio Frequency Con-
4B COMPUIE! JanucirYJ983
trol registers are located at 53762 {$D202), 53764 ($D204), and 53766 ($D206). A POKE 53764,128 would store a value of 128 (a B note) into the Voice 2 Audio Frequency Control register. SOUND 2,128, X,X will do the same. (See Figure 1 for a clearer representation of the four Audio Frequency Control registers.)
Now you can store a given frequency (note) into any of the four Audio Frequency Control registers. But what about distortion and volume? Look at the following sound command:
SOUND 0,X,10,12
This tells the computer to produce a pure tone (10) and a volume level of 12. Upon execution, the computer will convert the number 10 to 160 (160 is the actual pure tone code. See Figure 2 to find the corresponding distortion codes for the eight additional distortion levels), add 12 to it, and then store the result into Audio Control re- gister 0. This register is located at memory location 53761 ($D201 hex). Thus, the next two commands will perform the same task:
SOUND 0,X,10,12 POKE 53761,160 + 12
The three remaining Audio Control registers are located at 53763 ($D203), 53765 ($D205), and 53767 ($D207). A POKE 53767,160 + 7 would store a pure tone and volume level of 7 into Audio Con- trol registers. SOUND3,X,160,7 will do the same. (See Figure 1 for a clearer representation of the four Audio Control registers.)
You should now know how to store any given note, tone and volume level into any of the four voices provided by the Atari (and without using sound statements). The following two BASIC programs function identically;
10 SOUND 0,121,10,12 20 GOTO 20
10 POKE 53760,121
20 POKE 53761,160 + 12
30 GOTO 30
Ttie Built-in Spealcer
That is an overview of the sound that is channeled to the television speaker, but what about the built-
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in speaker? The built-in speaker is controlled via location 53279 ($D01F).
Program 1 will make the built-in speaker ran- domly click. (Not a very spectacular sound effect, to be sure, but that's not to be expected from BASIC statements.) Program 2A and 2B (which function identically) will also make the built-in speaker randomly click, but they do not use BASIC statements to produce the sound and will there- fore click the speaker much faster than will Pro- gram 1 . compare the two for yourself. The com- parison will give you some idea of the speed avail- able to you from machine language programming.
If you compared Programs 1 and 2, you might have thought: "If machine language can do that much for that little built-in speaker...." Yes, by using machine language you can greatly increase the quality of the sound that comes out of your television speaker.
I leave you with a simple machine language program that will demonstrate this increase in quality. The program is written in both assembly language (3A) and BASIC (3B). This is a simple program; it would have been half as long without the delay routine. However, the sound would not be audible if there were no delay built into the machine language program!
Program 1.
|
Figure 1. |
|
|
The Four Voices Provided By The Atari | |
|
|
VOICE 0 |
|
|
Audio Frequency Control Register Audio Control Register |
- 53760 {$D200) -53761 {$D201) |
|
VOICE 1 |
|
|
Audio Frequency Control Register Audio Control Register |
- 53762 ($D202) - 53763 ($D203) |
|
VOICE 2 |
|
|
Audio Frequency Control Register Audio Control Register |
- 53764 ($D204) - 53765 ($D205) |
|
VOICE 3 |
|
|
Audio Frequency Control Register Audio Control Register |
- 53766 ($D206) - 53767 ($D207) |
|
Figure 2. |
|
|
Examples Of The Eight Distortion Levels | |
|
|
Usinf |
; Random Voices |
|
SOUND O,X,0,V = |
POKE 53761,0 + V |
|
SOUND 0,X,2,V = |
POKE 53761 ,32 + V |
|
SOUND 3,X,4,V == |
POKE 53767,64 + V |
|
SOUND 1,X,6,V = |
POKE 53763,96 -t-V |
|
SOUND 0,X,8,V = |
POKE 53761,128 + V |
|
SOUND 1,X,10,V = |
POKE 53763,160 + V |
|
SOUND 2,X,12,V = |
POKE 53765,192 + V |
|
SOUND 0,X,14,V = |
POKE 53761,224 + V |
5 REM -THIS PROGRAM UTILIZES THE BUIL
T-IN SPEAKER USING BASIC STATEMENTS
10 fi=INT (256«RND ( 1 ) ) : REM -LOAD A WITH
A RANDOM NUMBER FROM O TO 255 20 POKE 53279, AiREM -STORE A AT 53279 30 GOTO 10:REM -START OVER
Program 2a.
5 jTHIS PROGRAM UTILIZES THE BUILT-IN SPEAKER FROM MACHINE LANGUAGE USIN G THE ASSEMBLER-EDITOR CARTRIDGE
lO *=*600
20 LOOP LDA *D20A ;LOAD A WITH A RAND DM NUMBER FROM O TO 255
30 STA S3279 ; STORE A AT S3279
40 JMP LOOP sSTART OVER
Program 2b.
5 REM -THIS PROGRAM UTILIZES THE BUIL T-IN SPEAKER FROM MACHINE LANGUAGE USING THE BASIC CARTRIDGE
10 FOR LOOP=I536 TO 1544
20 READ DATA
30 POKE LOOP, DATA
40 NEXT LOOP
50 X=USR(1536>
60 DATA 173,10,210,141,31,208,76,0,6
Program 3a.
5 ;THIS PROGRAM ON SPEAKER FR ING THE ASSEM 10 *=*&00 20 FREQ=«660 30 ; STORE A PUR
UME LEVEL OF
E O 40 LDA #175 50 STA ♦D20i 60 ; STORE CURRE
E O
70 START LDX FR 80 STX *D2O0 90 INX jINCREME 100 STX FRED 110 ;DELAY PROG 120 DELAY LDX # 130 LDDPl LDY « 140 LOOP2 DEY 150 BNE LOOP2 160 DEX 170 BNE LOOPl lao JMP START
UTILIZES THE TELEVISI DM MACHINE LANGUAGE US BLER-EDITOR CARTRIDGE
E TONE (160) AND A VOL 15 (160+15) INTO VOIC
NT FREQUENCY INTO VOIC
EQ
NT FREQUENCY LEVEL
RAM EXECUTION
15 15
; CONTINUE
Program 3b.
5 REM -THIS PROGRAM UTILIZES THE TELE VISION SPEAKER FROM MACHINE LANGUAG E USING THE BASIC CARTRIDGE
10 FOR L0aP=1536 TO 1563
20 READ DATA
30 POKE LOOP, DATA
40 NEXT LOOP
50 X=USR(1S36)
60 DATA 169,175,141,1,210,174,96,6,14 2,0,210, 232, 142,96,6, 162, 15, 160, 15 , 136,208,253,202,208,248,76,5,6 Q
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VIC Sound Generator
Robert Lee, Vancouver, B.C.
Adding sounds to VIC can significantly slow down a BASIC progrnm. The action stops and waits for the sound to finish. This could be especially annoying lohen you want a game to run as fast as possible. With this sound generator, you can add sounds in BASIC easily and xvilhout a speed penalty.
Among the novel features of the VIC-20 are its sound capabilities. These give it an advantage over the PHT, bringing a new dimension to game programs. However, one of the problems I and undoubtedly other VIC owners have encountered is that, while manipulating the sound generators in a BASIC program, it is not possible to do any- thing else.
This is especially a problem in game programs written in BASIC and using extensive graphics. Either you have to write such programs without complex sound effects, or you have to settle for slow motion.
Faster Sound
Faced with this problem, I decided to write a machine language {ML) program for the VIC which adds speed to its sound generation capabilities. Most of the sound effects we use in game programs are sounds with increasing or decreasing tones. For example, a simple way to simulate the sound of a laser with the VIC is:
FOR K = 250 TO 240 STEP -1 ;POKE36876,K:NEXT
The ML program works along these lines, except that it is necessary to use only one POKE com- mand. It generates sounds with increasing or decreasing frequency to make almost any kind of sound effect possible.
The program "VIC Sound" places a machine language program in the cassette buffer of the VIC. This means, of course, that you cannot trans- fer data using the cassette player while you are running the program. By changing the contents of memory locations 788-789 (decimal), the'inter- rupt system of the computer is used to run the ML program.
As you know, the VIC has four "speakers" to make music and noise. The first and second speak- ers, activated by POKEing memory locations 36874 and 36875, are used for sounds with increasing
52 COMPUni .Januaiv.1983
tones. The third speaker (36876) is used for sounds with decreasing tones. The fourth speaker, acti- vated by memory location 36877, is used mainly for explosions.
The ML program stores a starting number into the appropriate location and increases or decreases it for the period specified by the user. The interrupt of the computer will run through the program 60 times a second, which means that the starting number or tone will increase or decrease 60 times in one second.
Sound Duration
To make this a little clearer, let me explain that four memory locations have been assigned in the ML program to activate the four speakers, and four others to control the duration of the sounds.
Speaker To activate Duration
1st 846 858
2nd 847 888
3rd 848 918
4th 849 948
The number POKEd into locations 846-849 is the starting number which is stored in location 853 (dec); the initial value is 222, but this may be changed for the kind of sound you require. Loca- tions 858, 888, 918, and 948 control the duration of the sounds. The program will generate the sounds for the number of jiffies (the l/60th of a second interval used to measure time in Commo- dore machines) specified in these locations.
For a demonstration, RUM the program and then type SYS828; this will trap the interrupt. It will also set the volume control (location 36878) to maximum. Now POKE 846,222.
Location 858 contains 10 (dec), so the sound you heard v^'as for ten jiffies. What the program has done is store 222 in location 36874 (first speaker), incremented it by one every 60th of a second until ten jiffies elapsed, then stored 0 into the memory location to switch off the speaker. To change the duration of the sound to, say, 20 jiffies, POKE 858,20. Now POKE 846,222.
The same method can be used for the other speakers. POKE 858,10. To change the starting number (i.e., to get a tone which starts higher or lower), simplv POKE into memory location 853. For example, POKE 853,240. Now POKE 846,240.
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Explosion Simulation
It is necessary to POKE the starting number into locations 846-849; any other number will give only silence. Try POKE 847,240 (second speaker); it gives a sound of increasing frequency lii<e the first. Now POKE 853,222:POKE 848,222. You notice this gives a sound that decreases in fre- quency. POKE 849,222 will simulate an explosion. By manipulating the durations and starting number, you can get almost any kind of sound from the first three speakers and explosions from the fourth. However, when you are changing the duration of the sounds, make sure it is not too long; e.g., if you POKE 853, 50: POKE 846,222 the program will store 222 in location 36874 and in- crement by one every jiffy for 50 jiffies. But in this case the contents of 36874 would increase to 255 and then cycle back to zero. You would hear a note for only 33 jiffies, since a number less than 128 in the sound generators of the VIC produces silence.
When using this program, you cannot gener- ate sounds the normal way. To do so, you must first reset the interrupt vector by SYS996. This will also set the volume control to zero. To use the ML program, add the subroutine starting at line 8900 to your own BASIC program; and you can create sound effects using just one POKE, which would otherwise require a series of POKES.
In a BASIC program with lines 8900-9240 added, you would first have a line like this in the main program to enter the ML into memory:
10 GOSUB 8900 : REM SOUND GENERATOR
10 PRINT" {CLEAR] "
20 PRINT" {03 DOWN} {08 RIGHT} {REV}V
IC20{OFF}" 30 PRINT" {02 DOWN}{06 RIGHT}VIC SO
UND" 800 GOSUB8900 9 00 END 8900 FORJ=828TO1019:R£ADF:POKEJ,F:NE
XT 9000 DATA169,15,141,14,144,120,169,8
2 9010 DATA141,20,3,169,3,141,21,3 9020 DATA88,96,10,15,16,64,160,0 9 030 DATA16 2, 222, 173, 7 8, 3, 20 1,10, 17 6
9 040 DATA9, 238, 7 8, 3, 238, 10, 144, 7 6 9 050 DATAl 16, 3, 140, 10, 14 4, 2 36, 78, 3 9060 DATA208,6,140,78,3,142,10,144 9 070 DATA173,79,3,201,25,176,9,238 9 080 DATA79,3,238,11,144,76,146,3 9 090 DATAl 4 0,1 1,144, 236, 7 9, 3, 208, 6 9100 DATA140,79,3,142,11,144,17 3,8 0 9110 DATA3, 201, 16, 176, 9, 238, 80, 3 9120 DATA206,12,144,7 6,176,3,14 0,12 9130 DATA144,236,8 0,3,208,6,140,80
9140 9150 9.160 9170
9180
9190 9200 9210
VIC 20/PET/CBM OWNERS
ROADTOAD *- Hop your load across 5 lanes of ualfic, avoid deadiv snakes, ar.fl dodge (he dreaded loadealflfs. Cross a raging river full o1 logs, lurl^as, alligators, and park your toad in the saiety of a harbor. Each time you park S loads, you entef a tougher level wtiere the action is lasler and the load- caters ate more numerous. RQADTQAO is written in machine language and uses high resolution graphics. The sound effecls are exceJIent and you can use a joystick or the Keyboard to control your toad-
CASS/5(UVIC 20 $1 5,00
(CALIF RES ADD 6% SALES TAX] lAf ALLBAIUGcR - Blasi your way througli the dodge'm, blast'm, and a((ack motfes- II you destroy the bouncing balls delore they destroy you. the walls close in lor the next round. WALLBAI^GER is Mritten in machine languafle. has great sound, and encourages complex strategies CASS/5K/VIC 20/CBM B032
CASS/8K/40 COL 5CREEN/0LDNEW ROMS/FAT FORTY $1 5.00
, ^^^^ [CAUF RES ADD 6% SALES TAX]
Write for FREE cataJog:
NIBBLES G. BITS, INC. P.O. BOX eo'Ui
ORCUTT, CA S3i^e6
VIC-20 OWNERS
Expand your System with these Exclusive Factory Direct Products
A. DATASPAN-2D
• 5 slot-switch selectable (not an incon- venient DIP switch) allows control between computer mode and game mode
• Fully buffered
• Reset button
• Auxiliary power supply lack
• Fuse protection
• Write protection on one slot DATASPANKIt SS4.9S OATASPAN Assembled S79.S C. RAMcharger
• Turn your Coinmodore 6K cartridge into a lull 16K cartridge
• Fult address switching capabilities
• Sockets allow future EPROM substitulpon
RAItflctivger Kit $29.%
All assembled units have Digital Inlei^ace Systems Co. P.O. Box 8715 Portland, Oregon 97207 (503) 295-5890
B. RAM raider
• Makes your 3K or "Superexpander carliidgeafulMK RAM
• Recaptures your RAM for BASIC and moves it into Expansion memory (lower hall of Blocks 1.2. or 3)
DAMraider Kit S24.95 flAMraider Assembleil S34JS
D. BREEZE MACHINE
• Extend the tile of yoyi computer with our V/hisper Quie! FAN
• Plugsdirectly into your expansion port
• Designed lo work with any VIC compatible cartridge or expansion board
BREEZE IMACHINE Assembled $59.35 full 90-day limited guarantee.
TERMS:
Shipping and Handling $3.00 VISA/MASTERCAflD-Add 3°/o Most orders shipped within •18 hours (Personal checks — allow 2 weeks.)
VICTIPOFTHENIONTH
Tightly wrap R,F modulator and connectors with tin foil to help eliminate T.V interference
■VIC-20 is a trademark of Commodore Business Machines.
M COMPUTll Januory.1983
Exterminator by Ken Grant
First the bad news... this game is literally full of bugs. The good news? We guarantee hours of exciting enter- tainment trying to remove them. Some bugs you are likely to come up against are spiders, snails, fleas and centipedes in this rapidfire, 100% machine language, exceptional quali- ty game. Exterminator runs in stan- dard 5K VIC. '24.95
Antimatter Splatter! a more
dastardly alien could scarcely be found than one who would wipe out an entire civilization by dropping anti- matter anti-canisters, right? If your opinion of this alien troublemaker is the same as ours, probably your first thought was, get some matter! We say calm down! All is not lost. A mobile rapid splatter cannon capable of both breaking through his standard alien moving force fields and laying waste lo the ever-increasing number of anti-canisters is even now hovering above us. If only our cannoneer hadn't called in sick. ..say, what are you doing today? Anti-Matter Splat- ter is 100% machine language and runs in standard 5K VIC. '24.95
3-D Man The exact maze from probably the most popular arcade game ever with perspective altered from overhead to eye level. The dots. ..the monsters. ..the power dots. ..the side exits. New on-screen radar. This game Is amazing, 3-D Man requires at least 3K memory expander but will run with any memory add-ons (8K, 16K, 24K, etc.) that we have come across. '19.95
Defender on Tri As pilot of the
experimental Defender-style ship "Skyes Limited," you are the only hope for an advance party of scien- tists trapped in ancient alien sphere which suddenly (heat from collision course with sun presumably— G.E.) came to life. Four screens worth of unique defenses, on-off shields, fuel deposits, alien treasures, running timer, energy, score and very nice graphics display make Ihis one that does not quickly wax old. Defender
on TRI requires at least 3K memory expander, but will run with any memory add-on (8K, 16K, 24K, etc.) we have come across. '19.95
• • SPECIAL • •
Another NUFEKOP Big Deal to close this year out RIGHT! Weat NUFEKOP want to celebrate by giving you a gift. Our catalog. ..FREE. No, seriously, if you order both Antimatter Splatter and Exterminator, or three of the lesser-priced games, you may pick ONE FREE GAME from any of the above (except Exterminator.) Happy New Year!!
nUFEKUP
P.O. Box 156, Shady Cove, Oregon 97539-0156 C.O.D. Orders...call (503) 878-21 13
Mastercard and Visa cards accepted Ask for our new FREE catalog!
Games will be on tape unless you request disk.
Alien Panic Standard 5K VIC 20/combinalion slick & keyboard. This arcade-type game pits you against time and an alien on a six level construction sight with ladders and pitfalls, but not to worry! You have a shovel. '12.95
Krazy Kong The crazy gorilla has taken three fair maidens up to the top of the giant stairway. And you (the valiant hero) will attempt lo rescue them at the risk of your own life. Your timing must be totally accurate as you jump the barrels that Kong is rolling down at you. '12.95
Rescue From Nufon Adventure '12.95
Collide Crunch '12.95
Vikman Classic '1 2.95
Search Challenging '1 2.9S
SPECIAL OFFER! With any order of Exterminator and Anti-Mat- ter Splatter •mb'W send you a FREE 17" X 22" poster like the one shown above. Also available separately tor $3.50.
VIC is a trademark of Commodore Business Machines, Inc.
Easy Apple Disk Space Messages
Beirne L Konorski, Kent, OH
As diskettes fill up, it is useful to know how much room is left on them. Two methods exist for find- ing this number. One is to get a calculator or pencil and paper and add the figures. This seems point- less, since the computer is supposed to do those tasks. The alternative is to run the FID program from the system master. This is a nuisance, though, because you often change diskettes.
Since many people incorporate a CATALOG command into their greeting program, this would be the most useful place for a sector-counting subroutine. The DOS Mflnws/ contains two sections which help to solve this problem. The first is the RWTS (Read or Write a Track and Sector) machine language program (p. 94). The second is the listing of sector allocation (p. 129). The RWTS subroutine can be used to read the sectors containing the catalog and tally the amount of sectors used.
The diskette directory is located in track $11. It contains 15 sectors of catalog information, each holding the names and sizes of seven programs. The program reads one sector at a time beginning with sector $F and places it into the memory range beginning at $2000. The sector is then checked before the next one is read from the disk.
The seven program titles are checked for two things. The first is to see if the program is current. When a program is deleted, its catalog entry is not erased, but instead the first byte of the listing becomes $FF. If the program is current, then the bit containing the length is added to the running total. The Least Significant Byte of the total is stored in location $6074, or 24692. If there is a carry, it is placed in $6075. When all seven listings have been checked, the next sector is loaded, and the process continues until all fifteen sectors are read. The computer then returns to BASIC.
The rest of the BASIC program PEEKs the two locations containing the sum of the sectors used. The Most Significant Byte is multiplied by 256 and added to the LSB. This total is displayed and then subtracted from 496 to give the figure for the space remaining.
The program reads the DATA lines and enters the numbers beginning at $6000. It displays the CATALOG, then gives the results of the count. It can be substituted for your HELLO program,
56 COMPUTE! January, 1983
with your own personal touches like name and date placed before or after line 20, or after line 110.
10 D« = CHR* (4)
20 PRINT D*! " CATALOG "
30 FOR K = 24576 TO 24694
40 READ A
50 POKE K,A
60 NEXT
70 CALL 24576
BO X = PEEK < 24672) sY = PEEK < 24693)
90 Z = X + 256 » Y
100 PRINT i PRINT "SECTORS USEDi ";Z
110 PRINT "SECTORS REMAINING: ";496 - Z
120 END
130 DATA 169, 96, 160, 76, 32, 217, 3, 17
3, 11, 32 140 DATA 201, 255, 240, 3, 32, 99, 96, 23
8, 118, 96 150 DATA 173, 118, 96, 201, 7, 208, 2B, 1
69, 0, 141 160 DATA 118, 96, 169, 44, 141, 104, 96,
169, 11, 141 170 DATA 8, 96, 173, 2, 32, 201, 0, 240,
25, 141 IBO DATA Bl, 96, 76, 0, 96, 173, 104, 96,
105, 35 190 DATA 141, 104, 96, 173, 8, 96, 105, 3
5, 141, a 200 DATA 96, 76, 7, 96, 96, 0, 1, 96, 1,
0 210 DATA 17, 15, 94, 96, 0, 32, O, O, 1,
0 220 DATA 0, 96, 1, 0, 0, 1, 239, 216, 0,
24 230 DATA 173, 116, 96, 109, 44, 32, 141,
116, 96, 144 240 DATA 3, 238, 117, 96, 96, 0, 0, 0, 0
Use the handy
reader service cards
in the back of the
magazine for
information on products
advertised in COMPUTE!
[ "^yl
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iing like it before. Nothing else like it now!
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"'^Stevenson's graphic genius, first displayed in his It selling "Swashbuckler" sword fighting game, -. uutdoes itself in AZTEC. You're inside an ancient - Aztec pyramid searching for the golden idol.
-.. Descend deep into the heart of the temple- ts meet cobras, scorpions, giant lizards, hostile Aztec guardians and more. Watch for liidden trapdoors and strange death- ly -Be ready to fight, or run, crawl or to-nossible safety. The menace is Jtionsand strategy are yours. ,. .„„ .J never seen an adventure like [ Aztec! You'll never tire of its amazing •n-animation.and exciting challenge. .^ S39.95 for the Apple M " At your ^ computer store or:
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y
Juggler
Doug Ferguson, Elido, OH
For Atari ami VIC (with or witlwiit e.xpamion), this game will challenge anyone's dexterity. If you can score 50 with two balls or 500 with three, there is an extra surprise.
"Juggler" is a fast-action game I wrote in Sep- tember 1981 when the idea of programming BASIC was very new to me. It has undergone countless revisions since then, but the main loop (lines 860- 970) remains what it was the first night I strug- gled .
The purpose of Juggler is to use the joystick to control the arms of a cartoon juggler in his at- tempt to keep two or three balls in the air. The juggler's hands move in tandem and can be positioned to catch the three colored balls {inside, middle, and outside). Since this game is not for the timid, it requires a joystick because only game addicts know how to work them.
The balls are as random as I could make them and, contrary to the opinion of novice players, cannot land at the catching stage at the same time. The most important playing strategy is to make sure you hear the ball being caught before you move the hand toward another catch. The game can be slowed down merely by adding a few extra GOSUB 150 statements in the main loop, prefer- ably at lines 860, 900, and 940.
The game will run on either the unexpanded or expanded VIC-20. 1 would rather not explain how it all works, mainly because it often follows inconsistent logic and layout. One technical foot- note for those curious enough to investigate the program: instead of using zeros as values, I used a period (as in Y = .) because I read somewhere that this is faster and still zeros out the variable.
To start a game, push the joystick up or left for the three-ball or two-ball games, respectively. To repeat the same game, press the fire-button, or move the stick to change games. If you want to quit, hit Q.
58 COMPUTtI Janui3fv.1983
Program 1: VIC-20 Version
100 POKE36879,75:X=RND(-TI) :Y=2:G0T
0670 110 POKEV,15:POKEV-2,N:FORT=1TO10:N
EXT:POKEV-2,0 120 0=0+l+ABS(C) *9 130 PRINTTAB(7) " {WHTlSCORE "0"{HOME
HOME} "; : RETURN 140 DEFFNJ{X)-~( (PEEK(37151)ANDX)=.
) : RETURN 150 IFFNJ (16)ANDU=1THEMGOSUB360 160 IFFNJ (16)ANDU=2THENGOSUB420 170 POKEG+2,127:Q=PEEK(G) :POKEG+2,2
55 180 IFQ=119ANDU=1THENGOSUB480 190 IFQ=119ANDU=.THENGOSUB420 200 RETURN
210 IFPEEK (H) <64THEN330 220 RETURN
230 IFPEEK (H+2) <64THEN340 240 RETURN
250 IFPEEK(H+4)<64THEN350 260 RETURN
270 IFPEEK (H+16X64THEN330 280 RETURN
290 IFPEEK (H+14) <64THEN340 300 RETURN
310 IFPEEK(H+12)<64THEN350 320 RETURN 330 POKEJ%(K-A) ,32:D=K-1:GOSUB630:G
OTO540 340 POKEU% (L-B) ,32:D=L:GOTO540 350 POKEG% (M-C) , 32 : D=M+1 :GOSUB640 :G
OTO540 360 POKEH+2,32:POKEH+3,32:POKEH-1,7
4:POKEH,64:POKEH+l,7 5 3 70 POKEH+4,32:POKEH+5,32:POKEH+24,
32:P0KEH+23,77:P0KEH+25,32
SUNDAY DRIVER gives you four scenarios to choose from. You must beat the clock as you drive along while avoiding pedestrians, other cars, and obstacles. In other versions it's winter and you're on ice-slicked roads. In game three it's nighttime (don't hit the ghosts). If this sounds too easy try the 007 option — it's you against them on twisty roads.
SEND CHECK OR MONEY ORDER TO:
Software
P.O. Box 23 Worcester, MA 01603
MasterCard and VISA accepted (617)892-3488
16K cassette or disk $29.95.
Dealer inquines invited.
1982 A.N.A.L.O.G. Software
ATARI® is a trademark of AtARI, Inc.
38 0 POKEH+14,32:POKEH+15,32:POKEH+1 l,74:POKEH+12,64:POKEH+13, 75
390 POKEH+16,32:POKEH+17,32;POKEH+3 7,32:POKEH+35,77:POKEH+36, 32
4 00 POKEH+187,77:POKEH+188,78:POKEH + 209, 32 :P0KEH+18 1,103: POKE H+203,122:POKEH+180,32:U=.
410 RETURN
420 POKEH+l,74:P0KEH+2,64 :POKEH+3,7
5:POKEH,32:POKEH-l,32 4 30 POKEH+4,32:POKEH+5,32:POKEH+25,
32:POKEH+2 3,32:POKEH+24,7 2
44 0 POKEH+13,7 4:POKEH+14,64:POKEH+l 5,75:POKEH+12,32:POKEH+ll, 32
4 50 POKEH+16,32:POKEH+17,32:POKEH+3
7,32:POKEH+35,32:POKEH+36, 72
4 60 POKEH+181,103:POKEH+203,122:POK EH+18 7,101:POKEH+209,76:PO KEH+188,32:POKEH+180,32:U= 1
470 RETURN
A fumbled ball crashes in "juggler," VlC-20 version.
480 POKEH+3,7 4:POKEH+4,64:POKEH+5,7 5:POKEH+2,32:POKEH+l,32
4 90 POKEH,32:POKEH-l,32:POKEH+25,78
:POKEH+23,32:POKEH+24,32 500 POKEH+15,74:POKEH+16,64:POKEH+l
7,75:POKEH+14,32:POKEH+13,
32 510 POKEH+12,32:POKEH+ll,32:POKEH+3
7,7B:POKEH+35,32:POKEH+36,
32
5 20 POKEH+181,7 8:POKEH+180,77:POKEH
+203,32:POKEH+187,101:POKE H+209,76:POKEH+188,32:U=2
5 30 RETURN
540 GOSUB650:PRINTTABCD} "{21 DOWN} { WHT}CRASH{HOME}"; :P0KEV-1, N:POKE79 54-SC,15:POKEH-36, 34
5 50 FORT=15TO0STEP-1:POKEV,T:POKEV+
1 ,PEEK (V+1)AND2480RT 560 FORW=1TG100:NEXT:NEXT:POKEV-1, .
:POKE36879,75
5 70 PRINTTAB(7) "{YEL} {02 DOWN}GAME ~
OVER{DOWN} ":POKEH-14,64:GO
TO590 580 PRINT" {BLK}T{YEL} 3 BALLS
DOWN} ":PRINT" {BLK}«-
YEL} 2 BALLS{D0WN}":PRINT" PRESS {REV}Q{0FF} to Q
UIT":GOSUB140 590 GETA$:IFA$="Q"THENSYS65234 595 IFFNJ (32}ANDY<>2THENRESTORE:E=0
:O=0:GOTO710 600 IFFNJ (16)THENCLR:Y=1:GOTO700 610 IFFNJ {4}THENCLR:GQTO700 620 GOTO590 630 FORT=38884TOT+6 :P0KET-C0,7 :NEXT
: FORT=38900TOT+6:POKET-CO,
7:NEXT:RETURN 640 FORT=3888 4TOT+6:POKET-CO,6:NEXT
: FORT=38899TOT+6 :POKET-CO,
6:NEXT:RETURN
6 50 FORT=8165+DTOT+2:POKET-SC,123:N
EXT 660 RETURN 670 PRINT" {CLEAR} {DOWN} {YEL}V
IC JUGGLER{WHT} " 680 PRINT"{03 DOWN} {03 RIGHT}USE JO
YSTICK ONLY{04 DOWN}" 690 PRINT" {YEL} {04 RIGHT}CHOOSE GAM
E{DOWN}":GOTO580
7 00 V=36878:H=7968:G=37152:DIMJ%{18
) ,U%(16) ,G%(13) 710 PRINT" {CLEAR}"; : IFPEEK (36869 ) =1
9 2THENSC=3 584:CO=512 720 H=7968-SC:GOSUB140 7 30 FORX=8015TO8025:POKEX-SC,64:NEX
T:POKEX-6-SC,104 7 40 POKEH-37,93:POKEH-3 5,93: POKE H+7
:POKEH+118,102 7 50 POKEH-15,93:POKEH-13,9 3:POKEH-5
9,85:POKEH-57,73 7 60 POKEH-36,114:POKEH-14,8 2:POKEH+
8 ,114:POKEH-58,64:P0KEH+74
,102 7 70 P0KEH+139,78:P0KEH+141,77:P0KEH
+ 150,78 :P0KEH+164,77:P0KEH
+96,102 780 GOSUB360 790 F0RK=2T016:READJ%(K) :J%(K)=J%(K
) -SC:P0KEJ% (K)+30720+SC-CO
60 OWWWIB jQr,uory.1983
DRKAMIiVG or is it real? ^
Lost in a maze of haunted chambers . . pursued by fearsome creatures YOU*R£ TRAPP^pt^^ OLD
seek the key to your escape ... reach the Iron Door. Pay no attention to the footstcfi^jiehind ^it's not the psychopatlkJ^iller! ^ Concentrate— THINK! Fkid Your Mind*s Eye hidden in the Death TunneL WHERE IS IT? ^^^ .
THE NIGHTMAJRE, designed by Marc RusseU Beniof^^^?^
Offers... Ce&^Z
• Both Puzzle-Solving & Role-Playmg Intrigue!
• Superb Graphics, Sound 81 Color Animation!
• Hours of Challenging Horror! Requires... --»■
• ATARI 4001800 81 One Disk Drive
• One Player 81 Joystick ControUer ' ^^ Comes with....
• Game Prog ram & Complete Instrx
• BPYX30IFOKEVERWABRANTY'\
es^^JK,
Now Available At Your Favorite Deale For the name of your nearest EPYX "THENIGHTMAREjJ EPYX/Automated Simula 1043 Kiel Court, Sunni ''
coMPtrref? gam€S
EPYX Temple of Apshai was the very first computer game ever to win the Hobby industiy award for excellence. EPYX pledges you that same excellence in every game you purchase from us . . . the VERY BEST in entertainment!
EPYX 30/FOREVER WARRANTY *Our 30-day Unconditional Guarantee: If your EPYX Game has any defect whatsoever within 30 days of purchase, return it to us or your dealer and we will replace it free . *Our Forever Warranty: If anything happens to your disk at any time after 30 days, for any reason. Just send it back with 85,00 for shipping, and we will send you a replacement .
*AUaa 400I800 is a trademark of ATARI , IfiC .
,7:NEXT 800 FORK=2T014:READU% (K) : U% (K)=U% (K
) -SC:NEXT 810 F0RK=2T012:READG% (K) :G% (K) =G% (K
)-SC:POKEG% (K) +30720+SC-CO
,6:NEXT 820 K=INT(RND(1)*8)+2:A=1 830 L=INT(RND(1) *7)+2:B=l 840 IFY=0THENM=INTCRND{1) *6)+2:C=l 8 50 IFO>49+4 50*ABS(C)THENE=1:Y=. 860 GOSUB150 870 N=220:IFK=17THENGOSUB270:A=-1:G
OSUB110:K=15-E 880 IFK=1THENGOSUB210:A=1:GOSUB110:
K = 3+E
8 90 POKEJ%{K-A) ,32:POKEJ%{K) ,81:K=K
+A 900 GOSUB150 910 IFL=15THENGOSUB290:B=-1:GOSUB11
0:L=13-E
9 20 IFL=1THENGOSUB2 30:B=1:GOSUB110:
L = 3+E 9 30 POKEU%(L-B) ,32:POKEU%(L) ,81:L=L
+ B 940 GOSUB150 9 50 IFM=13THENGOSUB310:C=-1:GOSUB11
0:M=11-E 9 60 IFM=1THENGOSUB2 50:C=1:GOSUB110:
M=3 + E 970 POKEG% (M-C) ,32:POKEG% (M) ,81:M=M
+C:IFE=.THEN850 980 POKEJ% (K-3*A) ,32:POKEJ% (K-2*A) ,
81 990 P0KEU%{L-3*B) , 32 : POKEU% {L-2*B) ,
81 1010 POKEG% CM-3*C) ,32:POKEG% (M-2*C) ,
81:GOTO860 1020 DATA 7946,7902,7858,7815,7772,7
7 30,7710,7712,7714,7738,77
84,7829,7874,7918,7962 1030 DATA79 48, 79 04, 7860, 7817, 777 4, 7 7
5 4,77 56,7758,778 2,7827,7 87
2,7916,7960 1040 DATA79 50, 7 9 06, 78 62, 7819, 7798, 77
7 8,7 8 02,7825,7870,7914,795 8,
Program 2: Atari Version
lOO REM
1 10 GRAPHICS IS
120 GOSUB t60:GRAPHICS 19:P0KE 756, CH
SET/256: SETCOLOR 1 , 1 2 , 6: SETCDLOR
3, 4,8: SETCOLOR 2,0, lO 130 SCR=PEEK <B8> +256*PEEK (89)
#6; " '. "
# 6 ; " < { [I> t lU < f!> > "
#6; " <:C] "
*6:" t V."
ISO BALLS = 2:DI« B ALL* ( 3 ) : &ALLS= "G {[?>
t6J": POSITION 6,0:? #6;M*
190 GOSUB 320:P0SITlaN I,l5? «6;"ErEaa
140 POSITION 7.6
150 POSITION 7,7
160 POSITION 7.3
170 POSITION 7,9
?O0
?io
120 J30 ?40
E: " ; BALLS
POSITION lO, 1 : ?
F PRACTICE THEN
6; "HmEEH^"
K=PEEK (53279) : IF K=7 THEN
IF PEEK (53279) =K THEN 220
IF K=5 THEN B ALLS= 5-B ALLS
IF K = 3 THEN PR ACT I CE= 1 -PR ACT I CE
#6; " ta SPACES] POSITION 10,1:
:io
Atari Notes
Use your joystick to move the Juggler's arms to any of three positions (far left, center, or far right) to catch and (deflect the balls. You can select a game with either two balls or three balls by pressing SELECT when the game is RUN. If you press OPTION, you can play a "practice" game. In a practice game, you cannot make any points, but you can't lose, either. It's a gootj way to learn how to play without becoming frustrated.
A successful catch is greeted with a "bleep," but a miss gets you a raspberry. If you're not playing a practice game, it's all over when you miss a ball. The rest come tumbling down!
A note on strategy: let go of the joystick after each move. This will return the Juggler to the center position, where it is easiest to quickly react.
|
250 |
IF K<>6 THEN 190 |
|
260 |
POSITION 1,1:? #6; "{9 SPACES:" |
|
270 |
GOSUB 1190 |
|
280 |
REM ■;[:%.<; ■^•M::* |
|
290 |
GOSUB 320:eOSUB 320 |
|
3O0 |
GOSUB 440: GOSUB 320 |
|
310 |
GOTO 290 |
|
320 |
REM ■=faij=ai:l:lZH:S |
|
330 |
IF PEEK (53279) =6 THEN RUN |
|
340 |
P0S=2- (l-PTRIB(O) )+ (1-PTRI6 ( 1 > ) |
|
350 |
ON POS GOSUB 370,390,410 |
|
360 |
RETURN |
|
370 |
POSITION 6.7:? *6 s " < {[I><il> CE)' > |
|
:POKE 77,0 |
|
|
380 |
POSITION 8,9:? «6;"4 +":RETURN |
|
390 |
POSITION 6,7:? #6;" < { C: <: tE> 1 03 > " |
|
400 |
POSITION 8,9;? #6: "4 "/"jRETURN |
|
4 10 |
POSITION 6,7:? #6;" < <:E! f D> t CJ > " |
|
: POKE 77, 0 |
|
|
4 20 |
POSITION B.9:? »»6;"« 7.":RETURN |
|
430 |
REM mzi.vi.m-.r'.}mmm |
|
440 |
INDEX=(INDEX+l)t( INDEX < BALLS- 1 ) |
|
4 50 |
BPOS=BPOS ( INDEX) |
|
460 |
WHICH=WH1CH( INDEX) ; BDI R=BD I R ( I NDE |
|
X) :BIN=BIN( INDEX) |
|
|
470 |
POKE BPOS.O |
|
480 |
BPOS=BPOS+PB( WHICH, BIN) *BDIR |
|
490 |
POKE BROS, ASC (BALLS.( INDEX + 1 ) ) |
|
500 |
BIN=BIN+BDIR: IF BIN=0 OR BIN>PB(W |
|
HICH,0) THEN 530 |
62 COMPUIE Jonuatv.1983
Fbr the Atari 400/800 Home Computer ^^^^ggl^
'ou are Sentinel 1, the latest in highly maneuverable strike aircraft, and you have a mission, to protect the metropolis, but the alien attack will stop at nothing to destroy your very last lines . of defense. Your senses are tuned for battle and the ^ '^^^
attack begins. ^JH^^^^^g ^" — - -
Aliens will block your path, destroy your ship,
deplete your fuel and sacrifice their lives to stopyour <
mission. You must destroy the aliens with your rapid
fire lasers before they home in
and destroy you. There is no
escape — you must destroy them
all for they will stop at nothing.
S S<5s*\
-fr fTT '
y 1007(1 machine language
y 1 or 2 player option
f.-vii y joy stick controls
•. y' y lateral scrolling screen
•/superb graphics
y extensive color
y finest sound utilization
yavailable in 16K tape $29.95 U.S. funds
y 24K disc S54.95 U.S. funds
ycall your local dealer for more information
SOFTWARE
:,^;>^:>-fVl
Inhome Software Incorporated 2485 Dunwin Drive, Mississauga, Ontario L5L ITl. (416) 828-0775.
Atari is o registered trode mofk of Atari Inc Made in Conodo
510 520 530 540
550
560
570 580
590 600 610
620
&30 640 650 660
BIN CINDEX)=BIN BROS ( INDEX >=BPOS: RE REM ■H:h-W--Ijairr;l'j-C P=PEEK (BPaS+20) : IF O THEN 580 FOR W=14 TO O STEP 10,W: SOUND 1 , 60, 10. IF NOT PRftCTICE TH +1+9* (BALLS=3) : POSI RS <SCDRE) ) /2, 1 : ? #6 POKE BROS, 0: BDIR ( IN EX)jBDSUB 1260:RETU SOUND O, lOO, 12, 8: FO XT WjSOUND 0,0,0,0: EN 570
FOR 1=1 TO 10:F0R J POKE BPDS ( J) , ASC (BA BPOS ( J ) =BPOS ( J ) +20- O, I*BALLS+J, 12, lO-I POSITION 9,6:7 #6;" POSITION 5,0:? #6;" IF PEEK (53279) <>6 T RUN
REM mn:h**t-Am*-:i:Ti**.y.
|
TURN |
|
_ _ 1^^ 4=lri^ ■! hyj |
|
P028 AND P<>3 |
|
-2:S0UND 0,50, |
|
WrNEXT U |
|
EN 3C0RE=SCORE |
|
TIDN 10-LEN(ST |
|
; SCORE;" " |
|
DEX)=-BDIR ( IND |
|
RN |
|
R W=l TO 50:NE |
|
IF PRACTICE TH |
|
=0 TO BftLLS"l |
|
LL* (J+l ) ) |
|
BDIR tj) :SOUND |
|
:NEXT J:NEXT I |
|
DresE. i=»»:lr«i-- |
|
HEN 64 0 |
iPOKE CHSET+I,PEE O, I , 10,8: POKE 53
|
• JiU |
99le |
r |
||
|
^ |
Reaching li'ith nii oulstretclied arm in the Atari version of "jiiggier."
670 GRAPHICS 2+16:DIH M*(10)
680 M*=" JmrgBEr "
690 FOR 1=1 TO LEN <M4) : A=ASC (M« ( I ) ) : P
OKE 712, INT (A/16) «16+14 700 FOR J=l TO IIjCOLDR 32:PL0T I+J-1
,J-::COLOR AiPLOT I+J,J;SOUND 0,J
+I«10, 10,8: NEXT J:CDLDR 32:PL0T I
+J-I . J-1 710 FOR J=10 TO 6 STEP -IsCDLDR 32:PL
OT I+J/2+3. 5, J+1 ;COLOR A:PLOT 1+3
+J/2,J:S0UND 0, J+I t lO, 10, 8: NEXT J 720 NEXT I
730 FOR 1=0 TO 240 STEP lO:P0KE 712, O 740 A=PEEK (70B> : POKE 708 , PEEK ( 709 ): PO
KE 709, PEEK (710) : POKE 710,PEEK(71
1 ). : POKE 711, A 750 POKE 71 1 , PEEK (53770) : POKE 53279,0 760 SOUND O, I , 10. 4: SOUND 1,1+10,10,4:
NEXT I 770 SOUND O, 0,0,0: SOUND 1,0,0,0 780 GRAPHICS 2 + 1 6 : POSI T ION 7,6:? »6;ri
* 790 CHSET= (PEEK ( 106) -8) *256: FOR I=0 T
O 7:P0KE CHSET+I ,0;NEXT I 800 RESTORE 840: IF PEEK « CHSET+S ) =60 T
HEN 1030
810 FOR 1=128 TO 207;
K (57344+1 ) : SOUND
274, I : NEXT I 820 FOR 1=1 TO 14:READ A,B:FOR J=0 TO 7; POKE CHSET+A«8+J , PEEK ( 57344 +Bt
B+J): SOUND O . A . 1 0 , B : SOUND 1,B,10,
B 830 POKE 53274, A:NEXT J:NEXT I:SOUND
O, O, O, O: SOUND 1,0, 0,0 840 DATA 34,34,33,97,44,108,51,115,26
, 26, 42, 4 2,53, 1 17, 39, 103, 37, 1 0 1 , 50
, 1 14, 48, 48, 35, 99, 52, 116,41, 105 B50 READ A: IF A=-i THEN SOUND 0,0,0,0
:GOTO 10 30 B60 FOR J=0 TO 7: READ B:POKE CHSET+A*
8+J,B:S0UND O, B, 10, BsPOKE 53274, B
:NEXT J
GOTO 850
1,60, 126, 219, 2 55, 189,
870 880
890
900
910 920
930
940 9SO
960 970
9 80 990 lOOO 1010 1020 1030 1O40 1050 1060
1070
lOBO
10 90
1 100
1 1 lO 1 120 1 130
1 140 1 ISO 1 160 1 170 1 180 1 190 1200 1210 1220 1230 124 0 1250 1260
1270
1280 1290
1300 1310
1320
DATA , 60 DATA , 126 DATA 195 DATA DATA DATA 60
DATA DATA DATA DATA DATA DATA DATA
195, 126
2,24, 102, 165, 219, 231, 126, 122
3, O, 126, 126, 126, 126,231 , 195,
4,3,6, 12,24, 16, 112,0,0 5, 192, 96, 48,24,8, 14,0, O 6,60,90,219,255,231,231, 126,
7,0, O.O, 24, 24,0, 0,0 8,0,0,0,0, 63, 224, O, O 9,0,0,0,0, 252, 7, O, O 1 O , 1,67,166,28,0,0,0,0 11 , 128, 194, ioi , 56, 0,0, O, O 28, 128, I30,68, 60, 7,0, 0,0 30, I , 33, 18, 60, 224, O, 0,0
16, 24,28, 30, 30,2 8,24, 16
,19,19, ,-1,19, , -1 , 19, 19, 19, !0,0,-9
, J >=A:
-1
■1
DATA 127,
DATA -1
REM ■:i|.1-|-^ifc<:h*rf:T»*-^;fc*J.V
REM Read in parabolas
DIM PB (4, IS) : RESTORE 1060
DATA 0,-19,-20,-21,-21,-1,
20,20,0,-99
DATA 0,-20,-21,-21,-21,-1.
20, 21 ,21 ,0, -99
DATA 0,-19,-20,-21,-21
19,20,21,0, -99
DATA 0,-19,-20.-20,-21,
19,20,0,-99
DATA 0,-20,-21,-21.19,19,:
9
FOR I=0 TO 4
FOR J=l TO 15
READ A: IF AO-99 THEN PB ( I
NEXT J
PB ( I , O) ^J-1
NEXT 1
DIM BROS (2) , BPEEK <2) , WHICH (2)
DIM BDIR (2) , BIN (2) : RETURN
REM FifTr* it if :T* »^ ^ ^I:T Ka
FOR 1=0 TO 2: WHICH (I )=-l :NEXT I
FOR I=0 TO BALLS-1
BDIR< I>=-i+2* (RND ( 1 ) >0. 5)
INDEX=I : GOSUB 1 260
NEXT I
RETURN
REM »<?>** J=T**4^.]:i:^;T:T«
WHICH=INT (5«RND (0> ) : WH 1 CH ( I NDE X )
= -1
BROS (INDEX ) =SCR+13 0+INT (3*RND<0)
> -4* (BDIR ( INDEX) =-1 )
FOR J=0 TO BALLS-1
IF WHICH (J>=WHICH THEN J=BALLS:N
EXT J:GOT0 1260
NEXT J: WHICH( INDEX) t=WHICH
BIN<INDEX)=1+(PB(WHICH,0>-1)*(BD
TR ( INDEX>=-1 )
RETURN
64 COMWIB Jonoaiy,1<Pa3-
...and so there were l«eys for1heAtari400.
S&w;:
-VW'
:x^VL
ftS^
?^???^*iiri
?J^
"■^vSK
iSfi^V*
?;?S'te"
'MU'
NT
.n the beginning there was the membrane keyboard.
So it was to be done that Inhomc Software would create a full-stroke keyboard for the Atari 400 Home Qjmputcr and it would be called the B Key 400, and would sell for $ 1 1 9.95 U.S. funds.
The new B Key 400 was made so easy to install that the owner could do it himself in a miraculous two minutes.
With the B Key 400 keyboard from Inhome Software, you will follow into the land of professional home computers that arc powerful, easy to program and have a great capacity that can be made even greater with Inhomc Software 48K and 32K memory boards. It was done and it was good.
INHOME ^ SOFTWARE
Inhomc Software Incofporated, 2485 Dunwin Drive, Mississauga, Ontario L5L ITl. (416) 828-0775. Made in Canada.
ATARI rs a legislorcd iradernark of ATARI. USA
$85
$65
KM MM Pascii for PET/CBM
A subset o( standan) Pascal with extensions.
- Mactiine language Pascal Source Editor with cureor oriented window mode
- MacNne Language P-Code Compiler
- P-Code to machine language translatof fof optimiied object code
- Run-time package
- Floating point capatiility
- Usef manual and sample progfams
Reguires 32K Please specify configuration.
EARL for PET (disk file base^
EdUr, AttMUir, Rtlmtir. Uikir
Generates retaatable object code using MOS Technology mnemonics. Disk file input lean edit files largef ifian menxxy). Links .multiple object programs as one memory load. Listing output lo screen of printer. Enhanced editor operates in txMh command mode and cursor oriented "window" mode
RAM/ROM for PET/CBM
4K or 8K bytes, of soft ROM with optional t>attery backup.
flAM/ROM is compatitjie wjth any large keytjoard machine Plugs into one of the ROM sockets atxwe screen memory to give you switch selected write proteciatiJe RAM. tise RAM/ROM as a software development tool to store data or machine code tieyond the nonnal BASIC range. Use RAM/ROM TO LOAD A ROM image where you have possitile conflicts with more than one ROM requiring the same socket- Possible applications inclixie machine language sort (such as SUPERSORT), unrversal wedge. Extramoa etc. RAM/ROM - 4K $75
RAM/ROM -■ 8K 90
Battery Backup Option 20
SU BSORT by James Strasma $35
Subsort is an excellent general purpose machine language sort routine for PET/CBM computers. Sorts both one and two (jimensioned arays at lightning speed in either ascending of descending order. Othsr fields can be subsorled when a match IS found, and fields need not be in any special ofder. Sort arrays may be Specified by name, and fields are random length Allows sorting by bit to provide 8 categories per byte. The routine works with all PET BASICS, adjusts to any memory size, and can co-exisi with other programs in high memory.
SuperGraphics 2.0
NEW Version with TURTLE GRAPHICS
SuperGraphics, by John Fluharty, provides a 4k machine language extension which adds 35 full featured commands to Commodore BASIC to allow fast and easy plotting and manipulation of graphics on the PET/CBM video display, as well as SOUND Commands Animations which previously were too slow or impossible without machine language subroutines now can be programmed directly in BASIC Move blocks (or rockelships, etc ).or entire areas of the screen with a single, easy to use BASIC command Scroll any portion ol the screen up, down, left, or right. Turn on or off any of the 4000 (8000 on 8032) screen pixels with a single BASIC command In high resolution mode, draw verticaf horizontal, and diagonal lines. Draw a box. fill a box. and move it around on the screen with easy to use BASIC commands Plot curves using either rectangular of polar co-ofdinales (great (or Algebra Geometfy and Trig classes )
The SOtJN D commands allow you to initiate a note or series of notes (Of even several songs) from BASIC, and then play them in the background mode without interfering with your BASIC program This allows your program tp run at full speed with simultaneous graphics and music.
Seven new TURTLE commands open up a whole new dimension in graphics. Place the TURTLE anywhere on the screen, set his DIRECTION, lum him LEFT or RIGHT, move hm FORWARD, raise or lower his plotting pen. even flip the pen over to erase. Turtle commands use angles measured in degrees, not radtans, so even elementary school children can create fantastic graphic displays. Specify machine model (and size), ROM type (BASIC 3 or 4)
SupefGraptiics in ROM S45
Volume discounts available on ROM version for schools.
NEW VERSION II
fir rn/tll Ci^ftm
FLEX-FI LE is a set of flexible, friendly programs to allow you to set up and maintain a data base. Includes versatile Report Writer and Mail Label routines, and documentation for pro- grammers to use Data Base routine as part oi other pro- grama
RANHOH Jti:CE3S OATJI lASE
Record size limit is 256 characters The number of records per disk is limited only by record size and free space on the disk. File maintenance lets you step forward or bacfcward through a file, add, delete, or change a record, go to a numbered record, or find a record by specified held (or partial Held), Field lengths may vary to allow maximum information packing Both sub- totals and sorting may be nested up to 5 fields deep Any field may be specified as a key. Sequential file input and output as well as file output In WordPro and Paper Mate format is suppor- ted Record size, fields per record, and order of fields may be changed easily
MAIUKG USELS
Typical mail records may be packed 3000 per disk on 8050 (1 400 on 4040). Labels may be printed any number wide, and may begin in any column position. Tliere ts no limit on the num- ber or order of fields on a label and complete record selectjon via type code or field condition is supported REf>OflT WHITEH
Flexible pnnling format, including field placenenL decimal justilication and rounding Define any column as a series of math or trig functions performed on other columns, and pass results such as running total from row lo row. Totafs, nested subtotals, and averages supported. Complete record selectkia including field within range, pattern match and kigical func- tions can be specified,
FLEX-FILE II by Michael Riley $110
Please specify equipment configuration when ordering
Di^Kiiii;
lirteniiire Cm Uatt by LC Cirfile
COMPLETE DISK RECOVEHY SYSTEM FOfl CBM DRIVES
- edit disk blocks with ease
• duplicate disks, skipping over bad blocks
- complete diagnostic facilities
- un-scratch scratched files
- check and correct scrambled hies
- recover improperly closed files
• extensive treatment of relative (lies
- optional output to IEEE488 printer
- comprehensive user manual (an excellent tutorial on disk
operation and theory!. Furnished on cooy-prolecled disk with manual Backup disk available. St 0 additional.
$40
PROGRAM YOUR OWN EPROMS $75
Branding Iron EPROK^ Programmer for PET/CBM software for all ROM versions Includes ali liardware and software to pro- gram Of copy 271 6 and 2532 EPROMs
raRTMAKER bUALliS23^^^ ~
SERIAL PORT $63
Two ports with full bipolar RS232 buffering. Baud rates from 300 to 4800. For PET/CBM, AIM, SYM,
CBM Softtnre
TCL Pascal Version 1.6 Petspeed BASIC Compiler Integer BASIC Compiler CMAR Record Handler UCSD Pascal (without board) Wordcraft 80 BPI Accounting Modules Professional Tax Prep Sys. Intelligent Terminal Emulator ASERT Data Base Personal Tax Cat Dow Jones Portfolio Mgmt. Assembler Devekipment Legal Time Accounting
135 225 110 110 135 300 300 600
25 375
55 110
80 445
FORTH for PET
BY L C. Cargile and Michael Riley $50
Features include:
full FIG FORTH model.
aJ( FORTH 79 STANDARD extensions,
stnjctured 6502 Assembler with nested tiecision making macros.
full screen editing (same as when programming in BASIC),
auto repeat key,
sample programs,
standard size screens (IB lines by 64 characters).
1 50 screens per diskette on 4040, 480 screens on 8050.
ability to read and write BASIC sequential files.
introductory manual,
reference manual. Runs on any f6K or 32K PET'CBM (including 8032) with ROM 3 or4, and CBM liisk drive. Please specify configuration when ordering,
Mebcsm^ler far FORTH {30
simple metacompiler for creating compacted object code which can be executed independently (without the FORTH system!.
PaperMate 60 COMMANO
WOflD PROCESSOR
by Michael Rrley
Paper-Mate is a full- featured word processor lor CBM/PET by l/ichaef Ritey Paper-Mate incorporates 60 commands to give you full screen editing with graphics for all 16K or 32K machines (including 8032), all pnnters, and disk or tape drives. Many additional features are available (including most capa- bilities of Professional Software's WordPro 3|
For writing texL Paper-Male has a definable keyboard so you can use with either Business or Graphics machines. Shift lock on ietlers only, or use keyboard shift lock. All keys repeal
Paper-Mate text editing includes ftoating cursor, scroll up or down, page forward or back, and repeating insert and delete keys Text block handling induces transler. delete, append, save loail and insert.
All formatting commands are imbedded in text for complete coofrot Commands include margin controf sni release^ cdumn adiusL 9 tall settingSi variable line spacing. |ushfy text center text, and auto print form letter (variable block) Files can be linked so that one command prints an entire manuscript Auto page, page headers, page numbers, pause at end of page, and hyphenation pauses are included
Unlike most word processors, CBM graphics as well as text can be used. Papet-Male can send any ASCII code over any secondary address to any printer
Paper-Mate functkjns with all CBM/PET machines with at least 16K, with any type of printer, and with either cassette or disk.
To order Paper-M ate. please specify machine and ROM type Paper- Mate (disk or (ape) for PET CBM. VIC. C64 $40
SM-KIT tor PET/CBM $40
Enhanced ROM based utilities for BASIC 4, Includes both pro- gramming aids and disk handling commands.
BASIC INTERPRETER lor CBM 8096 tZOO
A full interpreter implementation to automatically take advan- tage ol the extra memory availaDle with 8096,
PEDISK II SyslBDis Irom cgrs Mlcratecli iinilible, FILEX IBM_3T41/2 Diti ExcltttigeSDltWirt mllltile.
JINSAM Bib Bite Mmigtmeit System lir CBM,
Comprehensive version available for most configuratkms,
COPT-WRITER WonI Proutur for PET/CBM. V 59
Works like expensive word processors. pKis has added fea- tures like double column printing and shorthand generate,
CASH MANAEEMENT- SYSTEM $4S
Easy lo use disk system. Keeps i rack of cash disbursements, cash receipts, cash transfers, expenses (or up to 50 cate- I gories
252 Bethlehem Pike Colmar. PA 18915
215-822-7727
A B Computers
WRITE FOR CATALOG
Add S 1 ,25 per (xder for shipping. We pay balance of UPS surface charges on all prepaid orders Prices listed are on cash discount basis Regular prices slightly higher. Prices subiect to change.
WE STOCK EAGLE COMPUTERS
ODmPUTER
ffi)
USI Wilefl Monitors— Green Of AMBER
20 MHz hf-res Deals and OEM inquiries
invited _ _
SPEcim on IHTHEGATEO CIBCUITS
6502 7'!5 10/6.95 50/6.55 100/6,15
6502A/6512A 8.40 10/7.95 50/7.35 100/6.90
6520 PIA 5.15 10/4.90 50/4.45 100/415
6522 VIA 6.4S 10/6,10 50/5,75 100/5.45
6532 7.90 10/7.40 50/7,00 100/6.60
2114-L200 2.45 25/2.30 100/2.15
2716EPR0M 4.90 5/4,50 10/4.00
2532EPR0M 8.90 5/8.45 10/7.90
6116 2KX8 CMOS RAM 8.90 5/8.45 10/7,90
4116 RAM 8fof14
Zerolnserlio52wsei'tji'>§95!SLi§?i!*§L ^^
A^-a/VAjLjAUiLj^L ni^^-M
Anchor Automation Signalman Modems
FREE SOURCE MEMBERSHIP WITH SIGNALMAN
All Signalman Modems are Direcl Connect, and include cables In connecl to your computer arid to the telephone Signalman Modems provide the ties! pf ice-periormance values, and start at less Itian S100, Dnllf ni DEM ii^tihtt inflri
Mark I RS232
Mark II lor Atari 850
Mark IV (or CBM/PET v^ith software
Mark V lor Ostximc (soltware available)
Mark VI tor IBM Personal Computer
Mark VII Auto Oial/Auto Answer
Mark VIM Bell 212 Auto Dial/Answer
DC HAYES Smirtmotem ZZi
RSZ32 mOOEH — /IcMUsHc 119
HSZ3Z MODEM — CCITT Irtqwiieitt 175
We carry Apple 11+ from Bell & Howell
16KRAMCanl X^i>^ lor Apple
Apple LOGO
Video Recordef Interlace
Super Serial Card
Thtralerclock Plus
280 Sohcard and CP/M
Parallel Printer Interlace/Cable
Grappler Interface
TG Products Joystick lor Apple
TG Paddles
DC Hayes Micromodem II
Videx 80 Column Card
fullFORTH+ (Of Apple (lig-Eoft(l)
Silenlype Printer and Card
Graphics Tablet and Card
Apple PASCAL Language
Apple FORTRAN
We stock EOUWARE Software
GENIS I Courseware Development System
Unicom Grade Reporting or School Inventory
Executive Briefing System with fonts
Apple Dumpling (MicrotBlcl Printer Interface Apple Dumpling with 16K Buffer PIE Writer Wonl Processor
65
150 545 149 119 295 80 139
48
32 299 259
85 310 645 195 160
145 250 225
115 160 120
Qcommodore
See us for Personal, Business, anii Educational requirements. Educational Discounts avaiiabla
PETSCAN $245 base price
Allows you to connect up to 35 CBM/PET Computers to shared disk drives and printers. Completely transparent to the user. Perfect for schools or multiple word processing con- figurations. Base conliguration supports 2 computers. AiJdi- tiortal coirputer fwokups $1 00 eacli
Commodore COI^MUNICATES!
COMPACK
$129
Intelligent Terminal Package includes: ACIA hardware iBsed interface, 0B25 Cable and STCP Sofl- ware with remote telemetry, transfer lo/from disk printer out- put, XOH-XOFF control, user program control, and status lint __
VE-2IEEEtoParal[ellnterface 119
Includes case, power supply, full a-dtt transmisskja and switch selectable character conversion to ASCII,
VIC 20 VIC Printer VIC 3K RAM VIC SK RAM V1C16KRAM VIC Disk Drive VIC Pinball VIC Omega Race Spiders Dl Uai^ (UMI) VIC Draw Poker
189 335 32 53 99 395 32 32 39 24
VIC Sargon II Chess VIC GORF Meteor Run (UMI) VIC Radar Ratrace Amok (UMI) Snakman Rubik's Cube programmeis Refcfence Renaissance (UMI) VIC Superslot
VICTORrSlltnrtltrVIC
Street Sweepers 12 Maiein3-D
Night Rider Treasures ot Bat Cave Games Pack I Victory CasTO Atfvcntuie Pack II
11 12 12
a
12
Cosmic DeBris Grave RoGbefS Advent Games Pack II Advetilure Park I Trek
TNW 488/103 with DAA Computel's First Book of PET/CBM POWER ROM Utilities for PET/CBM WordPro 3H- - 32K CBM, disk, prinlef WordPro 4-1- - 8032, disk, printer SPELLMASTER tpelling checker tor WenlPni CDPY-WBITEFt Professional Vlford Processor VIStCALC (or PET, ATARI, or Apple
PETRAX PET to Epun Gnphics Soitanre SM-KIT enbinceil PET/CBM ROM Utilllles
Programmefs Toolkit ■ PET ROM Utilities
PET Spacemaker II ROM Switch
2 Meter PET to IEEE or IEEE to IEEE Cable
Dust Cover (or PET, CBM, 4040, or 8050
VIC or C64 Parallel Printer Interface
CmC IEEE-RS232 Printer Interface — PET
SADI Intelligent IEEE-RS232 or parallel
Library of PET Subroutines
Prngnmning the PET/CBM (Cgmputel) — R, Wett
CompuW First Book of VIC
WMe PET Cilileg (Mideiglil Giutle)
Color Chart Video Board for PET
PET Fun and Games (Cursor)
32 32
39 24 20 15 13 15 39 23
12 12 11 12 12 _11
450 11 78 195 300 170
159 190
35
40
35
36
40
8
85
120
235
12
20
11
8
125
11
REVERSAL (Spracklen) Appie or Atari
SARGON II — Apple 0<TRS-80
Apple II User's Guide (Osborne)
Introduction to Pascal (Sybex)
Pascal Handbook (Sybex)
Musical Applicalions of Miaos (Ctiamtjertin)
Starling FORTH
Discover FORTH
User Guide to the Unix System
6502 Assembly Language Subfoutines
PET Fun and Games
KAMIKAZE (Hvden Software-Apple)
25 26 12
13 16 20 14 12 13 It 9 28
DISK SPECIALS
10/2,30 10/2.45
50/2.10 50/ 2.20
100/2.05 100/2.15
SCOTCH (3M) 5" SCOTCH (3M) 8"