$2.50 Recreational I n Canada $3.00 .------,r-, "--", 0

Adventures in Home Learning and Leisure Vol. 10 No. 2,1 .... 53, S.ptBmb"·Octob,, 1981

93063JOHNS~01 K2 BYRON ,B JOHNSON JR CIVIL ENGINEER JLB5 1 43 Ways t 0 4545-5~ INDUSTR IAL ST , Make MoneyFV, C4 93063 With Your Micro

in this issue: Start a Software Exchange! Who Are the Computer Criminals? - Recreational IEditorial ~@oou~lliJuD~

Publisher Typesetter Michael Madaj Renny Wiggins Editor Proofreader Marlin Ouverson Nancy Huebach Bringing Up Baby Assistant Editor Business Manager Julie Anton Maureen Christine Contributing Editors Marketing Director Dave Caulkins Craig S. Harper Dave Cortesi Advertising Sales n our last issue, we provided valuable information about how to select the Sea Wolf David D. Thornburg Kent Safford right personal computer. It's a bewildering feeling to walk into a computer Ramon Zamora Circulation Director Istore, knowing nex t to nothing and confronted with a major purchasing deci­ Art Director Peter Oark sion. But that's easy compared to the feel ing when you open your closet and Clifford West Circulation Assistant find a dusty piece of expensive hardware which hasn't been used in six months. Artist Leah Dansby One of the most embarassing questions you can ask any computer salesman Barbara Ruzgerian or manufacturer is, "What will I do with it?" He will have a handy reply, of course, but probe his answer. Will it really be easier to balance your checkbook NEW! ASCII on a computer than with a calculator? If he thinks so, better get a demonstra­ Notice to All Foreign tion. Games? Well, they are great, but should you spend a thousand dollars for the TRS-80* Subscribers : or so to play them? Then there is word processing - if you are an author. It Because the foreign postage rates have could be a bit extravagant to use a computer to write to mother. increased an average of 18 % since These points are all addressed to the home computer user. Educators have Every month you receive a certified ASCII C-20 cassette January, we've found it necessary to many useful applications for computers, and the software is slowly evolving to increase the price of foreign subscrip­ fill those areas. Small business software is in roughly the same category: lots of containing: a cover page with a directory of programs tions to cover the new rates. Effective uses, less actual software - but it's coming. Home users are a different story. with this issue the new Subscription What will you use your computer for? Rates for Recreational Computing are: Having a home computer is like having your first child. It can do just about 4 original programs S 22 One Year (6 issues) Canadal anything, but it needs to be taught how to do it. When a baby wants something, Mexico First Class Only it lays in your arms and cries, making you feel helpless until you discover what it an information packed newsletter $ 30 One Year World Airmail needs. When a computer needs something it sits on a table, silently making you $ 18 One Year Surface Mail feel equally helpless. A child grows up and becomes a responsive member of the and information on ASCII funded contests family. The computer can become a useful, integral tool in our lives but needs to be expanded. Given some peripherals and some software to suit your applica­ Subscription rates: $12.00 per year within the Rates: 1 year [12 issues] $40.00 United States; $22 for YlTst class to Canada and tion, it will not linger in the attic waiting for the next garage sale. Mexico; S30 for airmail to other countries. All What is needed is a little imagination. To help spark some creative ideas, we Foreign Subscriptions must be prepaid in U. S. called on Joe Weisbecker to write our cover story for this issue. Joe is the author 6 months [6 issues] $25.00 dollars drawn on a U. S. bank. of Home Computers Can Make You Rich. He has followed our magazine for Contributing Subscribers: $25/year ($13 tax years, and we are pleased to be able to present his work here. You will find he Sample issue $ 5.00 deductible) - Algorithmics, Inc., Gerald has given many imaginative ideas from which to draw. Bowman, Robert Connors, Mark Elgin, Joi Not everyone's imagination works strictly on the up-and-up. Although Write For Overseas Rates Ellis, John B. Fried, Scott B. Guthery, William people mature in their understanding of computers, their ethics do not always G . Hutchison, Jr., W. A. Kelley, Bill Kling, keep pace. Computer crime can be blatant or subtle, malicious or mischievous. William M. Richman II, Philip A. Smith, Joseph Paradoxically, small computers can also be used to help rehabilitate prison To subscribe, write to: ASCII A. Weisbecker, Brett Wilson, Patrick J. inmates. Two of our feature articles illuminate these points. McGovern. Retaining Subscribers: $50/year Speaking of legalities, software piracy is a well-worn topic. But did you ($38 tax deductible) - Dave Caulkins, Robert P.O. Box 516, Valley Stream, N. Y. 11582 Connors, Zenith Radio Corp. Sustaining Sub· know that educators have formed a very ethical, legally proper facility called scribers: $100+/year ($88 tax deductible) - Softswap, which allows access to hundreds of programs? Their example may show Level II 16K Required Byte Publications; Paul, Lori & Tom Calh oun; a way to get to the root of software piracy and eliminate it by removing its David Dick; Louis R. Patzke. Lifetim e Subscrib­ causes. Not even the majority of programs will ever be given away just for copy­ er: $900+ ($700+ tax deductible) - Bill ing costs, but having access to public domain software of good quality and rea­ Godbout Electronics. Co rporate Subscriber: sonable variety could be a very healthy thing for users and manufacturers alike. Star Wars Trench Star Fire $500/year ($440 tax deductible). We publish software in each of our issues which is for you to use. "Use" is Advert ising: Advertising space is available in the key word. You can learn a fairly good deal about programming just by typ­ *TRS-80 this publication. Please direct inquiries to the ing in the listings we publish and seeing what they do. Tme to fashion, each Advertising Director, Recreational Computing, computer will have a Slightly different version of the BASIC programming lan­ IS a Box E, Menlo Park, CA 94025,415/323-31 11 . guage. What will work on one machine will not quite work on another. Some Foreign Distributors of Recreational Comput­ minor tinkering with the lines which cause trouble should get the software to ing: UK & Europe: L P Enterprises, 8/11 Cam­ bridge House, Cambridge Road, Barking, Essex, work. How about sharing your modifications? product I G II 8NT, Great Britain. Hofacker- Verlag, Our magazine is continually working to make your experience with comput­ Tegernseer Strasse 18, 0·81 SO HolzkiJ"chen, ers more exicting and less frustrating. Home computers are out of their infancy, of West Germany, Asia & Australia: Computer but now they are in the formative years. Let us know how the transition is going Store, POB 31.2,61, 228 Milford Road, Milford, Auckland 9, New Zealand. ASCII Publishing, for you. Tandy 305 Hi Tario, 5-6-7 Minami Aoyama, Minato­ ku, Tokyo 107, Japan. 261, 22B Mi lford Road, Milford, Auckland 9, Corp. New Zealand. ASCI[ Publishing, 305 Hi Tario, 5-6-7 Minami Aoyama, Minato-ku, Tokyo 107, Japan.

Recreational Computing, September-October 1981, Issue 53 3 Recreational OO~~uD~ • September/October 1981, Volume 10, Number 2, Issue 53

EVERYONE IS TALKING ABOUT THE Learning About Computers ATARI® BOO'· COMPUTER. Color graph­ ics and English characters with truly 8 43 Ways to Make Money with your Micro by Joe Weisbecker high resolution; high quality sound; You say you can't justify spending that much money to play games or to expandable memory;and sleek, mod­ and so are we balance your checkbook? Feeling guilty about that unused computer in the ular appearance have made the 800 a closet? Here are lots of practical ways to put your computer to work earning "must have" for many computer hard cash! . users. And when you add ATARl's full line of advanced peripheral com­ 16 Who Are the Computer Criminals? by Jay BloomBecker ponents and comprehensive software They don't wear dark masks over their heads or gloves to hide their library you get a really hot deal, fingerprints. These criminals have more refined techniques than a cat burglar. whether your application is business, With both large and small computers they can transfer funds to their checking professional or personal. accounts, acquire gems, and get secret infonnation. How do they do it - and why? SPECIAL OFFER - ASAP makes the ATARI ®800'· the hottest deal in town 20 Micros Behind Bars by Mike Briggs by offering 16K bytes of additional On the other hand, computers are what you make them. This inmate tells RAM ... FREEl You get 32K for the how he uses his computer, and the hope it has given him for his eventual price of 16K at ASAP's special price of return to society_ only $799.00. So don't get caught out in the cold. Call ASAP today. 24 How to Start a Software Exchange byAnnLathropandBobbyGoodson The cost of software got you down? Worried about the piracy issue? Want to COMPLETE SOFTWARE LIBRARY INCLUDES try before you buy? A group of dedicated educators has formed a modern THESE POPULAR UNITS: trading post of good quality, reliable software. You can use their resources - Basketball ROM ...... $ 30.00 or you could follow their example and start a local software exchange! Super Breakout ROM ...... $ 30.00 Educational System ROM ..... $ 19.95 44 Number Systems by Alfred J. Bruey Video Easel ROM ...... $ 30.00 16 If binary, hexadecimal and octal sound like fonns of marine wildlife to you, Music Composer ROM ...... $ 45.00 then this article is definitely usefuL This simple yet complete explanation Computer Chess ROM ...... $ 30.00 shows what counts in the world of computer programming. 30 Tic Tac Toe ROM ...... $ 30.00 Star Raiders ROM ...... $ 34.00 Kingdom Cassette ...... $ t2.95 Blackjack Cassette. '...... $ 12.95 Games and Programs Biorhythm Cassette ...... $ 12.95 Assembler/Editor ROM ...... $ 45.00 30 Computer Knock- Knock Jokes by David J. Beard Mortgage Loan Analysis Tape . $ 12.95 The author provides programs in BASIC and in LISP for those who like corny Stock Analysis Disk ...... $ 19.95 jokes, or who are intrigued by conversational computer programs. Charting Disk ...... $ 19.95 Bond Analysis Disk ...... $ 19.95 32 For Photographers Only! by Joey Robichaux Mailing list Tape ...... $ 17.95 If you enjoy photography. read this article. You can learn to use your Touch Typing (2 tapes) ...... $ 19.95 personal computer to generate helpful charts and tables which can make your Graph It (2 tapes) ...... $ 17.95 hobby more fun and could improve your photographs as well! Energy Czar Tape ...... $ 12.95 Telelink (Terminal ROM) ...... $ 19.95 OPTIONAL ACCESSORIES 34 Fibonacci Nim by Mary Ann Gohlke ATARI" 410" Program Recorder $ 44 Space Invaders Cassette ..... $ 15.95 n This version of the classic Nim game is perfect for days when your computer "Scram ...... $ 16.95 ATARI" 810 Disk Drive ...... $ 475.00 supports a steady stream of curious people. The program is friendly and will ATARI" 815'· Dual Disk "Word Processor ...... $ 99.95 Drive ...... $1195.00 ATARI" 830n Acoustic play with several players at once - but how many of them will win? "Asteroids ...... : . Call for price Modem ...... $ 159.00 ATARI" 820'· 4O-column Dot Roman Numeral Conversum Prollramum by Ralph Roberts "Missile Command ...... Call for price Matrix Impact Printer ...... $ 279.00 ATARI" 850" Interface 38 "New item ATARI" 822" Thermal Module ...... $ 139.00 Cover ~Y PCC Productions This author knows why the Roman Empire crashed - his program will help Printer ...... $ 349.00 ATARI" Paddle (CX30-04) and prevent it happening again. Teach your computer to convert those alphabetics ATARI" 825" BO-column Dot Joystick (CX40-04) ...... $ 17.95 RECREATfONAL COMPUTING (ISSN #0164- to numerics_ Matrix Impact Printer ...... $ 625.00 light Pen (CX-70) ...... $ 64.95 5846) is published bimonthly by People's Com­ puter Company, 1263 EI Camino Real, Box E, ASAP offers a 12O-day buyer protection policy: full money·back guarantee jf not totally satisfied. Menlo Park, CA 94025. People's Computer IISII Ordering Inlormatlon: name, address, phone, ship by: UPS or Mail. Shipping charge: add $2.50 up to 11b. (UPS Company is a non-profit, educational corpora­ Departments blue), U.S. Mail add $1.50 (U.S. only) ($25.00 minimum order). tion. Donations are tax deductible. Second class computer postage paid at Menlo Park, California, and Terms: We accept caSh, check, money orders, Visa and Master Charge (U.S. funds only). Tax: 6% Calif. Res., additional entry points. Address correction re­ 3 Editorial 27 Programming Problems & Solutions products, inc. COD's and terms available on approval (School PO's Accepted). quested. Postmaster: send form 3579 to Box E, Menlo Park, CA 94025. Copyright 1981 by 6 ComputerTown, USA! 30, 32, 34, 38 Games & Programs 1198 E. Willow St., Signal Hill, CA 90806 Toll free outside California: (BOO) 421-7701 Inside California: (213) 595-6431 (714) 891-2663 People's Computer Company, Menlo Park, California. 14 Classroom Connections 40 Pocket Corner 42 Product News Recreational Computing, September-October 1981, Issue 53 5 IComputerTown, USA! by Bill Scarvie I

heavy-looking block that appears to be partially wrapped in paper and has several Securing Your PET wires attached to it. Immediately behind the transfonner you will find a black metal plate. It is attached to the left side wall and bolted to the bottom of the omputerTown, USA! recently had keyboard wire ribbon, the video monitor lower housing. Use the nut driver to re­ the misfortune of being victimized and the tape drive to allow the housing to move the nut from the bolt that holds by a sneaky, small-time vandal at tilt back even further. Carefully observe this plate down. C Having removed the plate, locate the our facility in the Menlo Park Pu blie Li­ the way these rib bon wires are inserted in brary. There was no real damage to any of their respective receptacles so that you backside of the computer's ON-OFF the machines. In fact, the only problem we can replace them the same way. switch, of the fuseholder and of the SUPERB QUALITY AT have had so far is that someone keeps tak­ As you face the open machine from power cord. Notice that the fuseholder ing the fuses and their caps from the back the keyboard position, locate a large is wired to both the power cord and the of the PETs. For awhile, we were buying transfonner near the left-rear corner of switch. One wire leads from each of them UNBEATABLE PRICES. replacement caps and fuses and, as soon as the lower section of the case. It is a large, to soldered connections on the fusehold­ we got them installed, someone would er. Use the diagonal cu tter to carefully come along and remove them again. Now, snip the connecting wires as close to the THATS MEMOREX I don't have the faintest idea what one fuseholder's connections as possible. would do with all those caps and fuses, Use the wirestripper to remove about but I do know that the computers don't 1/4 inch of insulation from the newly DISCS FROM PACIFIC work at all without them. So, we have cut wires. come up with a minor modification for Take the new fuseholder in hand and the "old-style" PET that moves the fuse use the diagonal cutter to snip each of the EXCHANGES and its holder inside the machine. Now wire leads to about 3 inches long. Use the our tormentor will have to take the en~ wire stripper to remove about 1/4 inch of tire top off the computer to get at the insulation from each of the wire leads. fuse. I don't think they will go this far Place one lead from the new fuse­ since the machines are in clear view of the holder beside one of the computer's wires library desk and the act of removing the so that the ends of the wires are even. In~ cover is sure to attract attention. sert the two wire ends into one of the wire nuts and turn the nut clockwise. The modification is a simple one that The PET computer . . . you can do with a few tools. If you don't This has the effect of "screwing" the nut want to do it yourself, I'm sure that your onto the wires. The wires are spliced and PET dealer, a local PET user or the near­ insulated in this way. Now take the other For Data Reliability­ est TV repair shop will be happy to help. fuseholder lead and computer wire pair Memorex The tools you will need are: a Phillips and splice them with the other wire nut. Flexible screwdriver, a nut driveT 0/4" for most That completes the installation. machines), a diagonal wiIe cutter and a There is no real need to replace the metal Discs wire stripper. Your supplies are: two plate, but you can if you want to. Be solder ~ less "wiIe nuts" and a new in-line sure to reconnect the video monitor, fuse holder. The fuse holder must have its power supply and keyboard to their own wire leads that can be spliced to the proper place before closing the cover and wiIes that are now connected to the exist~ replacing the screws that hold it down. Please note: this modification will ing fuse holder. There are some in~line holders that are supposed to be "quick undoubtedly void your computer's war­ connecting" to the existing wiIes, needing ranty. You will have to weigh this even­ no wires of theiI own. Unfortunately, the tuality against the need for fuse security. wires that are connected to the comput­ . . . its original fuse location .. . Reprinted by pennission from the er's fuse holder are too short to accom­ ComputerTowll, USA! News Bulletin. modate this type of holder. So, get the ComputerTown, USA! - A computer one with its own wires attached. literacy project of the people of Menlo Park, CA, the Menlo Park Public Library, CALL FREE FOR PRICES & INFORMATION and People's Computer Company, a non~ Unplug your computer before you profit educational corporation. P. O. Box begin this procedure! E, Menlo Park, CA 94025. Donations are tax ~ deductible. (800)235-4137 Begin by using the Phillips screw­ "This material is based upon work driver to remove the screws that hold supported by the National Science In California. (800)529-5935 or (805)543-1031 down the front of the computer's cover. Foundation under Grant No. SED They are located on the sides of the ma­ 8015964. Any opinions, findings, and chine, near the front and just below the conclusions or recommendations ex­ lip of the upper housing. pressed in this publication are those of DEALER INQUIRIES INVITED Once the screws are removed, open the author(s) and do not necessarily re­ the case and tilt the upper housing as far flect the views of the National Science back as you can. You should unplug the . . . and the new locatio n. Foundation." •

6 Recreational Comput ing, September-October 1981. Issue 53 he microcomputer field provides hundreds There are really only four basic ways to make of new ways to make extra money at home money in any field. You can sell products, sell Tin your spare time. Unfortunately, most arti­ services, create new products, or invest. Some cles and books emphasize business applications of ideas in each category will be described. Various microcomputers. While many experienced pro­ combinations of these four approaches are possi­ grammers are making money as small business con­ ble. But before getting down to specific ideas, let's sultants, this approach isn't practical for the aver­ consider how you will tum your idea into income. age home computer owner. To successfully pursue small business applications you need an expensive system, considerable experience, and more free time than most of us have available. You must also SELLING PRODUCTS worry about deadlines and unhappy customers. There are probably enough problems in your regu­ Mail order selling involves placing advertise­ lar job without asking for more in your spare time. ments for your product in various publications and Fortunately, there are many ways to make mling the resulting orders by mail. A small mail money with microcomputers that don't involve order business can easily be operated out of your conventional business applications. With a little home. This is an attractive spare time business if imagination your computer hobby can be profit­ you have the right product and a good ad. As a able as well as fun. I never buy a computer with­ first step you should read several books on the out deciding in advance how it can be used to pay mall order business in general. These can be found for itself. This should also be a primary considera­ in almost any library or bookstore. It is possible tion in your choice of a personal computer. By to start a business of this type with a minimum in­ letting your computer pay for itself, you can enjoy vestment. You'll need a post office box, a product it without feeling guilty about the expense. You source, and enough money for initial advertising. can even afford to own several computers! Advertising will be your biggest expense. A single, small advertisement can cost several hundred dollars. ... A low-cost, easy-to-mail product is ideal. It GETTING STARTED should not be available locally-in stores. If it is unusual, you might be able to get it mentioned for Your first step toward spare time microcom­ free in some computer magazines. puter income involves starting a list of money­ The price you charge must include the cost of making ideas. You should always be looking for advertising. Suppose that your product is a book­ these ideas. You can find them by reading books let that costs $1 to print and fifty cents to mail. and magazines or by talking to friends. Thinking Let's assume that your advertisement in a maga­ about products or services that you would like to zine costs $250 and the magazine has a circulation have available will give you more ideas. of 100,000. You might estimate receiving 100 or­ Sooner or later you'll fmd something that's ders from this advertisement. Your selling price for just right for you. Never pursue an approach that the booklet would have to be $4 just to break you don't feel comfortable with. Money-making even. This doesn't even include the cost of your ideas that are related to your existing interests or time. If your ad pulled less than 100 orders you hobbies are the best kind. You'll have an edge over would lose money. If you got 200 orders you your competition. An interest in fantasy gaming would make $250 (not including your time). The or bridge can be converted into salable computer effectiveness of your advertisement can make the programs. A teacher might be able to produce ex­ difference between success and failure. ceptional educational programs in her spare time. The secret to a successful mail order business This article provides a few potentially profit­ involves picking the right product and testing your able ideas for you to start thinking about. Many of advertising. You should run several different ads these only require a minimal amount of hardware. to see which one generates the most orders. You Some require none at all. Other ideas can be pur­ can specify Box 100-A as the return address in sued by beginners since skill is secondary to imagi­ one ad and Box 100 -B in another to measure the nation. My book, Home Computers Can Make You returns from each. Place small ads first so you can Rich (published by Hayden Book Company) de­ see if there is any interest in your product before scribes many other spare time money-making ap­ spending a lot of money. You might also want to proaches. Ideas involving articles, books, newslet­ test various prices for your product. A higher price ters, programs, games gadgets, tools, arts, crafts, sometimes turns out to be more profitable. attachments, computer-made products, inventing, In order to pick a product, to slant your ad­ investing, and services are discussed. vertising properly and to choose the best places to advertise, you must understand your potential Copyright © 1981 by Joe Weisbecker. customers. Hardware hackers, programmers, and All rights reserved. unsophisticated users are the three general types of

8 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September-October 1981, Issue 53 9 ~------

customers for your product or service in the ics for birthdays, anniversaries, etc. Color and there is any interest. Stores in shopping malls microcomputer field. By examining the various sound would be an added attraction. Your market should be interested in new, eye-catching, window computer publications you'll easily discover which would be unsophisticated owners of consumer­ displays. Color would be an added advantage for types of customers they're aimed at. If you see type computers. They would- receive a cassette this application. lots of circuit diagrams then it's a publication containing the ready-to-run customized program. Another type of service involves demonstrat­ aimed at hackers. Articles discussing operating sys­ Along the same lines, you might provide a ing computers in people's homes. It should be tems and programming techniques appeal to pro­ questionnaire. Parents would fill in their child's possible for you to make an arrangement with a grammers. General articles and ready-ta-run pro­ name, friends, pets, and interests. This information local computer store. You would earn a conunis- gram listings are slanted toward users. Some would be used in a personalized computer story or U sion on any computer that is sold as a result of products such as T -shirts, bumper stickers, and adventure game. TIle parents would buy the re­ / i . your home demonstration. You could even arrange computer jewelry might appeal to all three types sulting cassette. Again, you should only attempt I : home computer parties similar to those used to sell of customers. this with a very popular computer aimed at 'J kitchenware or cosmetics. An entertaining presen­ consumers in order to maximize your potential tation and interesting software will increase your market. chances for a sale. You could also offer potential By now you should be starting to think of customers a rental unit. Seeing how much fun they other products you could sell by mail. Add them can have will help them decide to buy their own to your list so you won't forget them. Ideas that interest in renting a computer for ·its entertain­ personal computer. don't seem practical now might be useful in the ment value. Adventure games should be ideal in future as microcomputers become cheaper and the this environment. home computer market expands. In particular try Skill sharpening provides another reason for to think of new ideas for personalized products. someone to rent your computer. Special drill and WRITING PROGRAMS FOR PROFIT test programs can be valuable for tutoring children who need extra help in a specific area. Someone might want to rent a computer just long enough to Writing a program is one way to create a new product. You can sell this new product yourself or SELLING SERVICES learn BASIC so that they can apply for a better job. There are programs that can be used to learn have someone else sell it for you. touch typing, bridge, and morse code. Blackjack First you must decide which computers to You can provide a wide variety of local com­ programs can be used for card-counting practice. create new programs for. This choice doesn't have Humorous computer bumper stickers could puter services in your spare time. None of the ser­ anything to do directly with the features or speci­ Software to help students prepare for SAT and provide a nice mail order product. They are inex­ vices discussed here involve business conSUlting. PSAT exams is available. All of these applications fications of various computers. You will generally pensive to make and mail. You don't even need a Some of these services require little or no skill provide opportunities to rent your computer. be most successful writing programs for the small­ computer. All you need is a sense of humor and while others require some programming ability. You could also rent computers to people who est version of the most popular computers. It's some imagination. If you are an engineer or pro­ Renting your computer to people is one type are interested in buying one but want to see if easy to see why. Suppose one type of computer grammer then you'll need to find a friend with a of local service you could provide. Look for appli­ they like it first. This is the same approach used by is owned by 200,000 people and another brand is sense of humor to think up ideas for you. This cations where someone only wants temporary use people who rent pianos to see if their children like only owned by 20,000 people. You will be lucky market should grow as the interest in computers of a computer. If they want a computer for long­ taking lessons before making a major investment. if one percent of the owners buy your program. increases. term use they will probably buy one instead of Other types of services would depend on your Would you rather sell 2,000 copies of your pro­ Unique, computer-related greeting cards renting it. People will really be paying you a small skills. Teaching various computer languages might gram or 200? Look at software advertisements in could be. designed and sold by mail. Computer fee for short-tenn use ofa specific program. be profitable. This could be done on your own or magazines to see which computers are most popu­ owners should be good customers for this type of The largest number of programs are available for an existing evening adult education program in lar with program publishers. item. Computer-related posters and jig saw puzzles for the original Radio Shack computer (Model 1, your neighborhood. The second decision you must make is how to could also be sold by mail. No computer expertise Level 2 BASIC). Since this machine is no longer in If you can program, it is possible to design market your program. You could sell the program is required to sell this type of product. production you might eventually be able to obtain customized, animated video displays for local yourself by mail. This involves making copies on Selling infomlation by mail is a popular busi­ second hand units at bargain prices. This would be cassettes or disk, preparing documentation, adver­ ness. Infonnation on consulting and lists of pro­ an ideal way to start a small home computer rental stores to use during special sales, etc. You would have to program some examples and determine if tising, filling orders, etc. You will probably be bet­ gram publishers are currently being successfully business with a minimal hardware investment. ter off letting an existing publisher manufacture sold by mail. Booklets of programs for small com­ Following are some rental service ideas. You and sell the program for you. This will give you puters such as the Sharp pocket computer or the should be able to think of many others. Such ser­ free time in which to develop other programs. The Sinclair ZX80 are nice mail order items. vices can be advertised in the classified section of publisher also assumes most of the risk for you. Local instant printing shops can print book­ your local newspaper. Be sure to spedfy what the All you can lose is some time. You can find pro­ lets for you. They are fast and inexpensive. You computer will do for people. gram publishers by looking at software ads in can prepare th~ infonnation yourself or pay some­ Children's birthday parties always need novel magazines. This will also give you some idea of one to write it for you. You might provide a guide forms of entertainment. Your computer could pro­ how much advertising each publisher does. Larger to stock market or gambling systems. A booklet of vide a variety of video games for a reasonable publishers are less likely to go out of business ideas for computer science experiments might sell. price. Parents might also be interested in renting a while smaller ones might be more willing to buy Information for specific applications, attachments, computer to keep an ill child occupied. It is im­ your program. or hardware modifications can be sold by mail. portant to provide a suitable selection of game You can sell your program to a publisher The possibilities are endless. You'll never know if programs along with the computer. There are even either on a cash or royalty basis. You are usually you can come up with a winner unless you try! adult game programs available if you don't want to better off with a royalty arrangement. Royalty Other mail order opportunities exist if you limit yourself to children's parties. rates vary from publisher to publisher. You can own a popular type of computer. You could de­ Elderly patients in rest homes are often lonely expect to receive at least ten percent of the pub­ sign and sell customized, animated video graph- and would welcome new interests. They might be lishers's income from your program. Royalties are

10 Recreational Computing, September· October 1981, Issue 53 Recreational Computing, September· October 1981, Issue 53 11 ------

in this area. Needs range from pre-school to adult Hardware articles can describe computer investment opportunities during the 80's. education. Talking computers should be ideal for modifications or homebrew attachments. Not all A third way to invest money is in yourself. teaching young children how to read. Adult educa­ magazines will buy hardware articles but those Investing in books, courses, and magazine subscrip­ tion software could be aimed at teaching money that do often pay well. Critiques of new hardware, tions are ways of increasing your money-making management or programming. Simulation pro­ languages, or programs can be sold if they are skills. Suppose that you get an idea for a $50 arti­ grams of all types fall into the category of educa­ timely and objective. You should remember that cle from a $5 book. This is a 900% return on your tional software. most magazines make a profit from advertise­ investment. It's hard to think of any better ways Better stock market investment software is ments. As a practical matter it is better to write to invest small amounts of money. needed. New stock or option trading systems that critiques of products you like. provide automatic buy and sell signals could be de­ You should subscribe to as many computer veloped. These and other programs should be de­ magazines as you can afford. They will keep you signed for use with on-line data bases. aware of current trends in the microcomputer field CONCLUSION Health applications is a wide open field. Can and provide lots of ideas for articles. In addition to a computer program reduce stress by using hypno­ articles, many computer magazines pay for book By now you should realize that microcomput­ sis techniques? Perhaps you can develop software reviews. If you have any artistic talent and a sense ers really do provide a wide variety of spare time for customized exercise or for calculating needed of humor you might be able to sell computer car­ money-making opportunites. We have discussed vitamin supplements based on family eating habits. toons to various publications. ten mail order product ideas and over a dozen ser­ You don't have to limit yourself to writing for vices that you might provide. Eight program ideas, computer magazines. You could also put your ten related to writing, and three investment ap­ computer knowledge to work by writing for proaches brings the total to forty-three. It's up to general interest publications. Men's magazines SPARE TIME WRITING you to expand this list and put the ideas that ap­ might be interested in how microcomputers are peal to you to work. You will find out that being used in automobiles, robots, and home Computer magazines always need new materi­ making money can be even more fun than spend­ appliances. Women's magazines might be interest­ al that will interest their readers. Some of these ~it. • magazines pay up to $50 per printed page. Writing ed in new computer career opportunities. The sub­ ject of microcomputers as a hobby could provide for these magazines can help pay for your comput­ Joe Weisbecker is a successful freelance writer articles for magazines aimed at retirees or parents. • generally paid on a quarterly basis but some pub­ er hobby_Even writing for magazines that don't and inventor as well as a professional computer The growing use of microcomputers in education lishers pay monthly royalties. pay can provide you with valuable experience and scientist. As a personal computer pioneer, he has provides even more material for general interest •, Some general guidelines should be followed prestige. Be sure to read several recent issues of been designing and using computers for 25 years. articles. for any type of program you develop. All of the any magazine that you intend writing articles for. He holds 25 patents, has had 2 books published, program publishers that I've talked to like graph­ This will give you a good idea of the style and type and is a senior member of the IEEE. 18 ofhis arti­ ics. You should try to use as much animation as of article the magazine will buy. Each magazine is cles have been published in magazines such as possible in your programs to enhance their sales different and something written for one magazine INVESTING Byte, Creative Computing, Popular Electronics, appeal. Programs like Android Nim and Dancing won't necessarily appeal to another. Slanting your and Magick. Awards include IEEE COMPUTER best paper award and RCA David Sarnoff award Demon owe most of their success to clever writing toward a specific publication will increase Your personal computer can be used in for outstanding technical achievement. Joe has graphics. your chance of success. managing your investments. Software is available created a wide range of new products including a You should also concentrate on programs that Most magazines have a free writer's guide to analyze stock prices and help you to decide don't require lengthy explanations. Programs simi­ available if you ask. Article submissions should be when to buy and sell. You can also obtain pro­ popular 8-bit microprocessor, several microproces­ sor support chips, one of the first programmable lar to popular arcade games sell well because typed double -spaced with your name on each grams that let you evaluate a wide range of put video games, several commercifll hobby computers, potential customers immediately recognize what page. When you submit an article to a magazine be and call option strategies. a new interpretive programming language. various they do. Without this instant recognition factor sure to include a self -addressed return envelope Instead of using your computer to analyze in­ toys and games, lots ofsoftware, and even a greet­ your programs will be much harder to sell. with the proper postage. Most magazines buy all vestments, you can invest in microcomputers. ing card. Hobbies include the stock market, Here are a few ideas for non-business pro­ rights to your article. Read a book on copyright Stocks of microcomputer or software companies meditation, beard growing, mentalism grams that you might work on. There is always a law before signing any contract. You can write can provide excellent investment opportunities. market for new game and novelty software. Ad­ a brief letter asking if there is any interest in the The price of Cut & Curl, Inc. went from $5 per venture games have become very popular and you type of article you're writing before you submit it. share to over $15 per share this year when they could try to think of some imaginative new sce­ Never submit the same article to two publishers at announced that they were planning on opening a narios. Can you incorporate more of an education­ the same time. chain of "software supennarkets." al aspect? Humor, color, sound and speech can be There are many types of articles that you Earlier this year Tandy Corporation (Radio used to enhance all types of games. might consider writing. Novel microcomputer ap­ Shack) stock was selling as high as $30 a share. In Animated TV puppets for young children to plications make good article material. You can de­ the last half of 1977, when Radio Shack an­ play with should appeal to parents. Color and scribe what you are doing with your computer or nounced the TRS-80 computer, you could have sound make this type of electronic busy box even what others are doing. Short programs or program­ bought this stock at an equivalent price of $4 per more attractive. This could be a good way to ming techniques that you have developed can form share. If you wanted more than a 600% gain in develop eye -hand coordination. the basis for profitable articles. four years you could have gotten it by buying and ' You might want to try your hand at develop­ Some magazines are interested in fiction or selling Tandy call options. ing new types of programming languages. Easy-to­ profIles of interesting people in the computer With computers as your hobby you are in a use languages for animated graphics or sound ef­ field. Tutorial articles on various aspects of person­ good position to uncover microcomputer-related fects should be salable. al computing are salable if well done. You should investment opportunities. Look for companies All sorts of educational programs are possible. try to develop new, imaginative teaching ap­ with products or services that fill a real need. The There is a major shortage of imaginative programs proaches for this kind of article. robot field should also offer some promising new

12 Recreational Computing, September-October 1981. Issue 53 Recreational Computing, September-October 1981, Issue 53 13 ---.------

IClassroom Connections r~~~~~~~~;;;;-;~;~;;;~;-;;;;~7~;~~;;~~~~~~~/~1

(} This comprehensive set of programs consists of simulated exam modules, a thorough diagnostic package, and a ~ complete set of instructional programs. It is designed to teach concepts and operations, provide drill and practice and '~ assess achievement levels through pre and post testing. The Competency Exam Preparation Series provides a structured, ~~\l sequential, curriculum encompassing mathematical, reading and writing instruction. The C.E.P.S. program is designed for individual student use or use in a classroom setting. Programs provide optional Computer Workshops printer capability, worksheet generation and performance monitoring. C.E.P.S. are available in two software formats. I National Proficiency Series...... $1,299.00 ~ N.Y.S. Regents Competency Test, Preparation Series...... $1,299.00 ~ for Mathematically If desired separate Mathematics and Verbal packages are available for $799.00 ea. A Spanish language version of the ~ I Mathematics Instruction Package is available at no extra charge. ~ Gifted Children COLLEGE BOARD PREPARATION SERIES 81/82 ~~~.T:;~",'; NORT~~~ARTM ~ Each program confronts the user with a virtually limitless series of questions and a~swers. Each is ba~ed ~:m pas~ exan:s ;..~~" and presents material of the same level of difficulty and in the same form used In the S.A.T. Scoring IS prOVided In ~~ Dana Hankins, Marietta, Oklahoma High School student seeks help from Dr. Richard V. Andree, accordance with the formula used by College Boards. professor of mathematics and of computing sciences at a recent two-week Computing and Problem S.A.T., P.S.A.T., N.M.S.Q.T., set includes 25 programs covering Vocabulary, Word Relationships, Reading Solving Workshop for Mathematically Gifted Students held at the University of Oklahoma each Comprehension, Sentence Completion, and Mathematics. Price $149.95 Spring. Sessions last from 9 a.m. until 9:30 p.m. with both group and individual instruction avail­ EDUCATOR EDITION - includes all of the above programs plus detailed solutions and explanations. Price $229.95 able for all. Independent Tests of S.A.T. series performance show a mean total increase of 70 points in students' scores. magine six dozen mathematically gifted Participan ts attended 4 hours of [Several different methods were Update Pack to 81/82 specs. Available to previous owners. Price $69.95 teenagers gathered for two weeks of hands-on computer lecture-demonstration developed - each of which produced Iintensive instruction on computer­ and from 4 to 8 hours of supervised the correct result.] assisted problem solving! "It was fasci­ laboratory during each day of the inten­ 49. Design a program to coach emergen­ ODYSSEY IN TIM E nating," said Dr. Richard V. Andree, sive 9 a.111. - 9:30 p.m., ten-day program. cy first-aid treatment at the Boy This spectacular adventure game adds a new dimension of professor of mathematics and computing Dr. Andree and Mrs. Andree, mathemati­ Scout level. The program should ask excitement and complexity to Time Traveler. Players must now sciences at the University of Oklahoma. cal educators, were assisted by six labora­ questions and then prescribe action compete with the powerful and treacherous adversary in their Andree and his wife, Josephine Peet tory assistants selected from advanced based on the response. [This was fun. Andree, who are well-known for their gifted students at the University of Okla­ Several unexpected results occurred exacting quest for victory. outstanding work with gifted, creative homa. to our highly imaginative young pro­ To succeed they must vanquish this adversary in combat that and talented youth, conducted the The workshops, part of an extensive grammers.] rages across 24 time periods. second annual Free Computing and Prob­ program for both the secondary and par­ Other problems successfully solved lem Solving Workshop for Mathematical­ ticularly the college level, is conducted by members of this gifted group include Odyssey In Time includes all the challenges of Time Traveler ly Gifted Students at the University of each Spring at the University of Okla­ problems on amicable pairs, sociable plus 10 additional eras, including those of Alexander the Great, Oklahoma, Norman. Two weeks were de­ homa with financial assistance from the chains, monkeys on typewriters, crypto­ Emperor Asoka of India, Anila the Hun, Genghis Khan. Each graphy, and the eight queens problem. voted to intensive work on microcomput­ University of Oklahoma Associates. game is unique, and may be interupted and saved for later play. er programming and computer-assisted The outstanding problem-solving Each problem in the 75 involves special problem solving. Participants were select­ ability displayed by the group enabled difficulties for beginners on a micro­ available for APPLE & TR-80 PET, 32K - $39.95 ed from among gifted students who will them to produce numerous solutions to a computer. be returning to their school system nex t set of seventy-five difficult micro-research Although the majority of partici­ ISAAC NEWTON year and who had completed a year of problems proposed in the text Explore pants were from the state of Oklahoma, Perhaps the most fascinating and valuable ed~ mathematics beyond first year algebra. Computing with TRS-80 and Common students from three other states were ucational game ever devised - ISAAC NEWTON TIME TRAVELER Students had to be sufficiently gifted so Sense (Prentice-Hall, 1981). A few sam­ also involved. The Andrees hope next challenges the players to assemble evidence and their principals permitted them to miss ple problems include: year's applicants will come from even fur­ discern the underlying " laws of Nature" that have Confronts players with complex decision situations and the demand for real time action. Using the Time Machine, school to attend this outstanding pro­ 1. Determine all N 1,000,000,000 ther distances. Low-cost dormitory hous­ produced this evidence. ISAAC NEWTON is an < inductive game that allows players 10 intervene players must face a challenging series of environments that gram, because May 25 -June 5 was the such that N*N ends in N. Example: ing will be available for non-commuting only time the extensive micro computing participants. actively by proposing experiments to determine if include; The Athens of Pericles, Imperial Rome , N = 76, since 76*76 = 5776. [Some new dala conform to the "Laws of Nature" in facilities of the University could be made Many of this year's participants plan Nebuchadnezzar's Babylon, Ikhnaton's Egypt, Jerusalem at programs required overnight comput­ question. Players may set the level of difficulty the time of the crucifixion, The Crusades, Machiavelli's available exclusively for this group. Mini er time, others generated all such N . to have programs to disp lay at the day­ from simple to fiendishly complex. (VAX and PDPl170) and Macro (IBM long Computer Science Student Fair and Italy, The French Revolution, The American Revolution, in less than two minutes run time.] In a classroom setting the instructor may elect to and The English Civil War. Deal with Hitler's Third Reich, 360/158) computers were also available Brag Session which will be held on Satur­ choose "laws of Nature" in accordance with the 16. Find a "Pythagorean box" having Vikings,etc. At the start of each game players may choose a for individual use, but most of the work day, October 17, 198 1, in the Physical complete instruction manual provided. integers (whole numbers) for length, level of difficulty ... the more difficult, the greater the time concentrated on TRS-80 miCrocomputers Science Center at the University of Okla­ For insight into some of the basic principles underlying width, height and all six surface di­ pressure. To succeed you must build alliances and struggle which are easily available to school sys­ homa, Norman. The Fair and Brag Ses­ ISAAC NEWTON see GODEL, ESCHER, BACH by Douglas agonals. [Many such boxes were R. Hofstadler, Chapter XIX and Martin Gardner's MATHE­ tems. Students who were accepted could sion is open to student computing buffs with the ruling powers. Each game is unique. found. None were found that also MA TICAL GAMES column in Scientific Americ.ln, October, invite a parent or teacher to accompany of any age and from any location. Last $24.95 had integral internal (body) diago­ 1977 and June, 1959. S24.95. them. Schools were limited to I or 2 year's fair brought students from 6th nals. Noone knows if they exist or participants unless they could furnish grade to junior college level. The only extra computers for additional applicants. not. I prerequisite is a knowledge of either Originally planned for 50 participants, ad­ 20. Write a program to create Haiku programming or electronics and an inter­ :::;~::;t:;:~;::~:~~;:C.t'IOgUe~-~ ! Krell Software Corp. ~ ditional computers were rounded up by poetry. [Solutions included 3 pro­ est in sharing knowledge with other com­ participants so 73 persons could finally grams to write English Haikus, and puter buffs. Write or phone Dr. Andree, be accepted. Only students with out­ one to create Haiku poetry in Japa­ Mathematics Department, The University ~u:~~:,O~I::~:;::I;n~;::I:dl '1= 21 Milbroo:e;,~v:~~~~n:r ;':~:.Y :;d1~~~~ ~ standing records for reliability, deport­ nese.] of Oklahoma, Norman, OK 73019- o disk or 0 cassette (please specify) (516) 751-5139 .~ ment and honesty as well as high mathe­ 39. Compute and print the number 2t75 (405) 325 -3410 for an application and All programs requJre 16K/TRS-SO programs require LEVEL /I BASIC/APPLE programs reqUIre APPLESOFT BASIC NY Srare Resldanrs Add Silles Tax ~ matical ability were considered. exactly, correct to the last digit. further details about either program. • ~~~28288e8e~~~~~~~~~288e8e~~~~~~~~~~~~~~~ 14 Recreational Computing, September-October 1981, Issue 53 "

he fashion, a resounding "No." of enough for journalists IO.:'''.IP ' Many computer money to meet sud­ T and criminolo­ criminals just aren't 1-----.. den needs. Another gists, is to see all that clever. Their may see it as a play­ computer criminals crimes are not that pen - simply a place as geniuses. Donn technically sophisti­ to play computer Parker, in his book ca ted. And even if it games as long as he Crime by Computer, were true, this view or she likes. These reflects this when he of computer crime different percep­ writes: "Perpetrators wouldn't be very tions, and the atti­ are usually bright, helpful. No test has tudes they reflect, eager, highly moti­ been devised to will generally lead to vated, courageous, separate computer very different types adventuresome, and geniuses who are of computer crimes, qualified people will­ prone to crime from and require different ing to accept a law abiding comput­ types of security to technical challenge. er geniuses. Lacking prevent them. They have exactly this type of test, it In this article, I the characteristics wouldn't make much shall suggest seven that make them high­ sense to ask a person­ views of the comput­ ly desirable employ­ nel director to screen er system which ees in data process­ out all geniuses lest seem to summarize ing," F. W. Dennis, they commit com­ most of the cases writing in Security puter crime. that I have seen. World in September Environment, • The playpen The 1979, paints the personality, American education­ same picture: "The seems the most use­ al television network common denomina­ ful factor in predict­ recently broadcast a tor in nearly all cases ing compu ter crime one-hour show a­ of computer fraud and preventing it. bout computers as has been that the The data suggest that tools in the educa­ individual is very certain "criminogen­ tion of nine and ten much like the moun­ ic environments" are year olds. About the tain clim ber - he or present in most com­ only discordant note she must beat the puter crimes. By in this paean was it is criminogenic envi­ one teacher's obser­ ronments I mean the vation that her stu­ pic­ computer system, as dents kept erasing ture accurate? Does the criminal per­ each other's names it help us to prevent ceives it immediate­ from computer sign­ computer crime? ly before he or she up lists, or destroy­ Based on my analy­ decides to commit a ing the sign-up lists sis of many of the computer crime. For altogether. The cases in the files of example, one type teacher tolerated the National Center of computer crimi­ this aberrant behav­ for Computer Crime nal will see the com­ ior, apparently de­ Data, I must answer pu ter environment lighted that her stu­ both questions with as a cookie jar - the dents enjoyed play- ing at the computer. its rules and practices. Unless these clearly communicate the computer crime is a subclass of white collar crime, I am not computer crime as a way to strike out against the computer. Older students have the same morality. Professor John limits on unauthorized computer use, and the rationale for surprised that these pressures operate here as well. Case his­ Thus, they see a war going on, not between the employer and Carroll found that 34 per cent of the students in two courses these limits, the user will continue to be vulnerable to the tories of computer crimes bear me out. themselves, but between themselves and anyone of a number on advanced information systems at the University of Western computer "game player" who goes too far. One head teller at a bank in New York City was found to of different forces. Ontario had tried to obtain computer time without paying for • The land of opportunity Not too far removed from the have stolen $1.5 million when his bookie was raided and it In some cases, the slogan of the 1960's - I am a human it. The same percentage had tried to penetrate the computer's playpen perspecitve is the attitude that there's nothing much turned out that he was betting up to $30,000 a day. And in being; do not fold, staple, or mutilate me - has been convert­ security system. wrong with exploiting an obvious vulnerability in a computer Denver, Colorado, Raymond Ressin financed numerous ed into an unreasonable dislike for the computer itself. In one These examples demonstrate the fact, obvious to any­ system. Unlike the game players in their playpen, those who gambling trips to Las Vegas by falsifying the input to the com­ case, a programmer sabotaged a computer by short-circuiting one who has watched people play computer games, that see the computer environment as a "land of opportunity" puter of the stock brokers for whom he worked. the computer's memory. He told the police that he had an simply using a computer can be intrinsically satisfying. seem to be motivated not so much by challenge as by lack of To counteract people whose need drives them to cookie "over-powering urge" to shut the computer down, and had no They also suggest that the drive for this satisfaction can challenge. Where the game player might try hundreds of codes jar crimes, companies must investigate employees before they grievance against the owners of the machine. violate other's rights. When computer crime results from to find one which gives entry to the computer's operating sys· are hired. But situations change, and security must be respon­ Terrorist bombings reflect a much more extensively devel­ the attempt to gain satisfaction from working with the com­ tern, the employee in the "land of opportunity" just finds and sive to these changes. Ideally, the relationship between em­ oped symbolism. In Italy, the Red Brigades produced a telling puter, I categorize it as an ~xample of the playpen percep­ exploits a vulnerability in the system - often in the course of ployees and their supervisors and management in general will document, Resolutions of the Strategic Directorate that de· tion getting out of hand. Unfortunately, there is no standard learning his or her job. For example, the operator of a device be such tha"t the employee will seek out help when a problem picts increasing computerisation in Western countries as part within the computer industry to define precisely when the for printing cheques pressed the REPEAT button again and arises. of a sinister plot to "maximize social controls." The Resolu­ playing has got out of hand. Thus, if a student uses an hour again when his own cheque was being produced. Hardly the • The war zone Some people see the computer not as a solu­ tions explain that because computers are instruments for the of computer time without permission, one university com­ computer genius the media would have us think all computer tion to life's problems, but as a symbol of their cause. Dis· "repression of the class struggle ... it is important to attack, pu ter department considers it criminal theft of services and criminals are, he took a dozen cheques and attempted to cash gruntled employees, who feel that management is out to get unravel, and dismember these networks of control." another views it as commendable ingenuity. them all at the same time. More sophisticated, but similarly them or that they have already been hurt unfairly, may ex­ Where the computer symbolizes personal frustrations, the In addition to the unauthorized use of time (and often as opportunist, Jack Polak exploited his position as a purchasing press their resentment in attacks on the company computer. security measures to deal with the problem are not much dif· a necessary prerequisite to it) attempts to compromise com­ agent in the county of San Diego, California. Knowing the This type of employee sees the computer as a "war zone," the ferent from those called for in the war zone. But soapbox puter security systems are common to those with a playpen troubles the county was having in installing a new computer­ battlefield in the struggle between employer and employee. crimes are as likely to be committed by non·employees as by point of view. An English group calling itself Crank boasts of zied system to control its payments for goods bought, Polak In Sacramento, California, three employees of the State dissidents within. These sorts of attacks on the computer em­ expertise in "compute;r piracy and security cracking." Mem­ set out to compromise the system. He created fictitious ven­ Department of Justice, apparently annoyed by the paltry phasize the need for attention to physical security. The com· bers of Crank claim to have obtained files from universities dors, charged the county for non-existent supplies that had os· amount of their pay increase, deleted certain arrest records mon practice of making the computer center the highlight of a and companies in England, including one whose security "has tensibly been delivered, and collected approximately $50,000 from the State's criminal records. There are numerous other public relations tour is thus a questionable risk, and companies never been broken," all with the ostensible purpose of making in payments. He knew the county's system too well. Only his tales of computer library tapes erased, misfiled, or mislabelled, should ensure that they stay aware of the activities of sure that computer security is improved. But it would take impatient questioning about a $70,000 cheque he awaited led or instructions to erase all company records two years after terrorists. only a small change in the motivation of Crank members to to his detection. a certain programmer is fired. Employees have even literally • The fairyland If any category of computer criminal com­ wind up with someone who seeks to outsmart the computer One needn't be a profound criminologist to realize that attacked the computer with sharp instruments, screwdrivers, pletely belies the major myth, it is this one. Some of the par· for his or her own benefit. motivation is directly proportional to opportunity, and and guns. ticipants in computer crime appear to act as though the com­ This may have been the dominant motivation behind opportunity is inversely proportional to the security of a sys­ In one of the most extreme cases I know of, an employee puter environment were totally divorced from reality. A telex Stanley Rifkin's infamous computer crime. When Rifkin tem. If the opportunities are obvious enough, even the least of a large produce company, feeling cheated out of a sub­ operator may routinely transfer millions of dollars from bank pleaded guilty to charges arising from his theft of $10.2 million sophisticated employees (or outsiders, for that matter) may be stantial pay rise, created a "shadow corporation" for revenge. to bank without recognizing how important each transaction from an American bank, he described his reaction to what he expected to try to exploit them Consequently, the need for The shadow was almost exactly like the real corporation, ex­ is. The computer simply isn't real. had done. "I was aghast," he said, explaining that his arrest systematic and extensive security cannot be underestimated. cept that it was about 0.75 percent less efficient - more vul­ In Computer Capers, Thomas Whiteside tells of a fraudu­ was the first indication he had had that his scheme really Simple measures - such as taking particular care of employees' nerable to theft, spoilage, and so forth. All of the financial lent transfer of $2 million. The culprit convinced his girlfriend worked. He further explained his failure to hide the diamonds accounts which are under the computer's control, rotating differential between the shadow corporation and the real to transfer this amount to his bank in New York, telling her he he had bought with the stolen funds, saying he hadn't made personnel from job to job, and looking for any trends of corporation went into the pockets of the disenchanted wanted to playa joke on a computer-operator friend who any plans for this contingency. Implausible as this story may irregular work habits which might either give rise to or explain employee. worked at that bank. The friend and the money disappeared seem, it is consistent with Rifkin's general ineptitude as a computer crime, are just some of the measures that a company As in the case of the "cookie jar," good management is before the girlfriend realized that she had been conned as well thief and his rapid arrest once he returned to America. Further might take to reduce its vulnerability to those who see the the best prevention. Where there are no acceptable avenues to as jilted. support for the idea that Rifkin had a playpen perspective computer as a land of opportunity. express resentment toward the employer, management should Although it is perhaps dangerous to take assertions of comes from an associate who once taught with Rifkin: "The • The cookie jar A gambling debt, a drug habit, sudden losses not be surprised when unacceptable avenues are used instead. ignorance at face value, the message behind cases such as this is guy is not a bank robber, he's a problem-solver," was Profes­ on the stock market, may all lead an employee to see the There is also the possibility that the employee's resentments quite clear. Where people associated with computer systems sor Gerald Smith's opinion. funds in a computer as the best solution to his problem of the are well· founded. Corrective action will not only reduce the are unaware of their own power, and act as though there were In view of what I have already said about the playpen atti­ moment. As though it were a cookie jar, the "hungry" crimi· threat of the resentful employee, but will also demonstrate to no dangers of computer crime, the company who employs tude towards computer environments, certain security impli­ nal dips into the computer to take what he needs. In such cir­ all employees the folly of perceiving the computer as a war them is exposed to an enormous risk. Just as management can­ cations immediately become evident. Norms that clearly cumstances, the criminal's motivation is much more pressing zone. not afford to ignore the new vulnerabilities a computer creates define allowable and excessive computer use will develop, and than his observation of a loophole in the system's security. • The soapbox In the war zone, the criminal gets at the em­ in any business, so it cannot afford to have employees who are if the industry does not develop them, it's quite likely that the Criminologists have identified such "situational pressures" as ployer through the employer's computer. The soapbox com­ ignorant of these vulnerabilities. Clear communication of the law will. In the meantime, each computer user must evaluate frequent accompaniments to white collar crime in general; as puter criminals find computers themselves anathema, and see responsibilities of the job, as well as clear standards for its per- 18 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September-October 1981, Issue 53 19 ----~ ------

i Micros Behind Bars I "Herman and Me" I; i by Mike H. Briggs INDEX LISTING 'BASIC' PROGRAM

BY: STEVEN ENTRINGER & MIKE BRIGGS have been in prison for the last sixteen years. I still ======have fifteen years to go. I have a TRS-80 named I'Herman.' We've been together about a year now, and This is an indexing program that I use for calling my we've become great friends. I've sort of gotten used to cassette tapes, either by artist name, by tape #, or by I the idea of Herman being smarter than me, but then e title. Also a default line sends you back to the index if a I that's the reason I got him in the first place. 'selection is not listed.' i I got interested in computers quite by accident. I The program is written in Level 2 BASIC. You will I formance are the most obvious management tools to combat have a rather large cassette tape collection and reels of That solved my problem, except with very loud noises. need at least 16K or more memory for a healthy index. this problem; the company should make it clear that each em­ music along with a couple hundred LP's. I was looking I'm working on solving that also and I think I have, but *See note on bottom of program sheet for memory ployee has a stake in computer security. for a way to index them, and had made several tries with I'll have to wait till I have enough funds to send for the space. I The other side of the fairyland mentality is that even if a typewriter, but I didn't like any of them. Then one items I need. I want to expand my 48K system with one To see a sample 'RUN' see the last page of this the employee's ignorance of computing does not facilitate a day I was looking at my new Radio Shack Catalog and disk drive into at least two drives and a printer so I can article. I crime it may stand in the way of that employee detecting the saw 'Herman.' Well, it was love at first sight. But how work on the voice system I am developing. Data lines start at line 320. You will not have to i [he early warning signals which, acted on promptly, might could a prisoner get a computer into this place, much I have the time on my hands to develop my know­ enclose any infonnation within quotes, the program runs reduce crime. It is clear to me that one of the important secur­ less in his cell? Well, I found out. I just asked the super­ ledge of computers to an extent that I would not be able very well without them, this makes listing the data easier I, ity devices in a manual system is that lots of people see each intendent and the idea was taken before a staff meeting. to on the outside, and I intend to take full advantage of and much faster and saves on space. Also you don't have ! piece of paper, and they can tell unusual entries just because Finally, I got the approval. But I was still in trouble. that. I hope to leave here with a good working know­ to list in any order except of course each listing in itself. • they run counter to common sense. To some extent we lose First, I didn't have the slightest idea how to run a com­ ledge of computers and computer systems. Example: ~ Of all the things I've dabbled in so far, I feel the this security advantage when systems are computerized - and puter much less the money to get one. I called the 320 DATA E. ARNOLD,I,WELCOME,I & 2 no longer easily understood by many people. If we could only Radio Shack Store and got the complete price along computer will playa major role in my life. I want to be This is one data element within a statement that get the game fanatics to teach the residents of fairyland about with tax, and then I asked the accounting office how a part of the future, and I want to be able to do some­ gives you the four (4) columns to each row thus: I computing, both might develop more realistic perceptions of much I had in my account. I found out I had a little thing that will allow me to earn a living and keep out of 320 DATA E. ARNOLD,I,WELCOME,I & 2, the computer environment. more than it would take to purchase a Level I 4K sys­ places like this. I think computers are the answer, and as E. ARNOLD,2,WELCOME,I & 2 ! • The toolbox To some computer criminals, a computer is tem, so I did. far as I am able to find out (it's hard to keep up with This would produce two rows four columns each. developments in here) computers are fast becoming a simply a computer. Thus, we have cases of so-called com­ When Herman got here, I sat down and just looked If you make the title too long then you force the side # puter crime where the computer is not the target, but the im­ at him. Then I opened the manual that came with him commonplace appliance in home and business. The to drop down a row which in tum forces a space on the ! things you can accomplish with a computer are stag­ plement in a crime that in no other way involves computing. and was surprised to find I could make sense of it right screen thus: The phone freaks, who use microprocessors to test phone cir­ off. So I plugged Herman in and followed the instruc­ gering. I don't think most people have a full idea of the 320 DATA E. ARNOLD,I,WELCOME,I & 2, impact of computers on their lives. They will soon be I cuits and develop strategies that enable them to use phones tions, and now my system boasts 48K, one disk drive, SCHUBERT,45 ,SYMPHONY # 8 OP.2,1 & 2 everywhere: in the home, the business, the schools, and for free, exemplify this attitude towards computers. The a speed loader and a voice. (I got a VoiceTek system so When run the 1 & 2 would be down a line and your I will be a part of that new and exciting world. I Equity Funding personnel, who used computers to create false Herman and I can talk back and forth.) listing would read: ~ One thing I would like to see in this prison would insurance policies by the thousands, seemed similarly clear­ Another con and I developed a tape listing program ARTIST TAPE # TITLE SIDE # headed about what a computer can do. Perhaps the most ludi­ that handles my tapes real well. I also have an informa­ be a school for teaching computer basics. With the hold SCHUBERT 45 SYMPHONY # 8 OP.2 ! crous example is the' Los Angeles brothel owner who used a tion listing program that I modified from one of the they are taking on our lives, now would be the time to 1&2 minicomputer to keep track of his customers. many books I bought. I have an address listing that takes train people how to use them, and I can't think of a Therefore if I run into a long title I shorten it so it I These examples suggest a type of computer criminal we the place of my address book, and I have developed a more 'captive' audience than those doing time in prison. fits. By running the program using the index listing # 2 ! can call the technological crook, who sees the computer as store inventory listing that works with the infonnation When I first came here in 1966, J didn't have any you can start calling up each tape by the tape number another tool in his kit. This type of person is more likely to that is required to operate a store within a prison. I'm idea of ever getting out, but now with some skills that and check each listing before you finish the program already be a criminal than any of the individuals whose atti­ working on a program for the handicapped, which uses will allow me to earn a living and do things that are listing and data inputting. tudes I described above. As the key to this sort of crime is endless tapes and allows a person with motor problems exciting and useful, my entire outlook has changed. I computer use, all those strategies which limit access to the to operate a computer with less buttons to push. Also, now know that I can make it, and because of that, 1 computer are important security. But none of these "limited I have the theory and paperwork done on a program for will. But first, I have much to learn, some of it things 'Bout Myself and Steven I, access" security procedures will be at all effective against the the blind and handicapped that works with voice appli­ that people who haven't been exposed to a place like owner of a micro- or minicomputer who has worked out a cations, both ways: a complete 'talking computer sys­ this take for granted. Examples? I went to town one day ,! way to use the computer to commit crime. tem' that allows a blind person to communicate with the a few years back to get a tooth fixed and when the I'm in prison. Steven just got released after serving outside world via computer. car stopped J couldn't get out because I couldn't find eight years. He is currently on work/release and in I, What To Do Next I have sent for and received both hardware and soft­ the door handle. Another time I went into a store and al­ school learning computer programming; his class is using The categories listed here are not mutually exclusive, ex­ ware from several companies and have had little or no most got hit by a door that opened before I got to it. Or TRS-80's. I have had my computer, 'Herman' for about haustive, or chiselled in stone, and I encourage feedback ­ trouble obtaining them, except for the lack of funds. I the time I went into a bank with a sponsor so he could seven months now and have grown really fond of him. particularly as to attitudes I appear to have missed. Further­ earn a wage here but it's rather small, so when I want pay a bi1l. While standing there waiting, a man asked if It took me some time to get Level II (funds). Steven more, the categories may not be much use when we want to something I usually have to save for several months be­ he could help me. I said, "No, I'm just browsing." Boy, wrote the indexing program after only two weeks of predict whether a specific individual is likely to become a fore I can send for it. was J red! studying Levels I & II. Up until that time he had never criminal (unless we can develop tests to discover if a "suspect" I am especially interested in the voice applications I will have many things to overcome when I seen a computer except in articles. So when he asked me is abnormally likely to perceive the computer environment that a computer can be used for, and with that in mind face the world again, but now I have the power to do to let him try to write a program for me I told him what along the lines the categories suggest). Still, if the company I've purchased the VoiceTek system. When I first started just that. Computers, of course, didn't change my think­ I needed and this is what he came up with. Steven wrote sees the environment as a playpen, a cookie jar, or any of the using it, I found I had trouble with background noises ing altogether, but they have shown me a way of life the program while 'Herman' was still in Level I, and that I thought was only for college kids or very smart other models I've discussed, it may be inferred that some so I installed a CB Mic with a noise cancelling preamp. therefore hadn't seen the program work. After I got people. would-be computer criminals will see it that way as well. I Level II I ran the program and worked out the bugs. • hope that the security measures I have outlined here will offer Mike Briggs #520850·MSU, P. O. Box 520, Walla Walla, 'Herman' and myself take this time to thank you for some strategies to change or prevent these potentially danger­ WA 99362. your interest. Please feel free to write. LISTING ON PAGE 22 ous perceptions. •

20 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September-October 1981, Issue 53 21 --~.------! ------~ I DISK DRIVE WOES? "Computers, of course, didn't change Coming Soon I PRINTER INTERACTION? "Herman and Me" CHILDREN'S MEMORY LOSS? my thinking altogether, but they have ERRATIC OPERATION? DON'T BOTHER ME, I~ shown me a way of life that I thought I'M LEARNING I Don't was only for college kids or very smart i Blame The people." Software! Power Line Spikes, Surges & 'HERMAN' A TRS-80 LEVEL" 16K+ SAMPLE 'RUN' OF TAPE LISTING I Hash could be the culprit! TAPE LISTING PROGRAM 7/30/80 PROGRAM Floppies, printers, memory & processor o!ten interact! Our unj~ue ISOLATORS eliminate equipment interaction AND curb damaging 11/10/80 BY: ! Power Line Spikes, Surges and Hash. ======STEVEN ENTRINGER • ISOLATOR (150·1) 3 filter isolated 3·prong sockets; integral WRITTEN BY STEVEN ENTRIGNER MIKE BRIGGS ~:~:~s~~~~ ~.u.~~r~~~~~~ ; . ~~~~ ~ . ~~ ~~ ~.u.~ .'~~~ : ,1, ~~ .'~a£6;~~ EDITED BY M. BRIGGS 11/10/80 ! • ISOLATOR (150·2) 2 triter Isolated 3·prong socket banks; (6 ======See and listen to children learning .1 sockets total); Integral Spike/Surge Suppression; 1875 W Max 10 CLS on a computer in this motivating ! load 1 KW either bank ...... $62.95 RUN 20 ' FILE "A" 24 minute film on the use of the • SUPER ISOLATOR (lSO·3), similar to 150·1 except double TO MAKE A REQUEST FOR AN ARTIST: TYPE # I I filtering & Suppression ...... $94.95 30 GOTO 220 computer in the classroom. DBMIL • ISOLATOR (ISO·4), similar to ISO·1 except unit has 6 TO MAKE A REQUEST FOR A TAPE #: TYPE # 2 40 ?"TO MAKE A REQUEST FOR AN ARTIST: is an excellent introduction into i Individually filtered sockets ...... $106.95 TO MAKE A REQUEST FOR A TITLE : TYPE # 3 • ISOLATOR (ISO·5), similar to ISO·2 except unit ha s 3 socket TYPE # I the future and benefits of com­ banks 9 sockets total ...... $87.95 TO MAKE A NEW LISTING GOTO 320 OR BEYOND: ! • CIRCUIT BREAKER, any model (add·CB) ...... Add $ 8.00 50 ?"TO MAKE A REQUEST FOR A TAPE # : puter assisted education. • CKT BRKRISWITCH/PILOT (·CBS) ...... Add $16.00 TYPE# 2 ======TYPE #?I For more information on how you Master·Charge, Visa. American Express 60 ?"TO MAKE A REQUEST FOR A TITLE: Order Ton Free 1·800-225-4876 ARTIST'S NAME? E. ARNOLD can preview this important in­ {except AK. HI. MA. PR & Canada) TYPE # 3 ARTIST TAPE # TITLE SIDE # novation in education write: 70 ?"TO MAKE A NEW LISTING GOTO 320 OR E. ARNOLD I WELCOME I & 2 L£77 Electronic Specialists, Inc. BEYOND: CRM/McGRAW HILL 171 South Milln Slreel Nal,d Mass 01760 E. ARNOLD 2 WELCOME I & 2 110 Fifteenth St. I T hr ,I' fJ , I)(~ J I' 17 f", lr, \) 80 ?'-======" E. ARNOLD 3 WELCOME I & 2 90 Z=O: INPUT"TYPE #";X: ON X GOTO 100,130, Del Mar. Ca. 92014 IF YOU WISH TO SEE THE INDEX AGAIN, PRESS 'ENTER' KEY? 160 714-453-5000 100 INPUT"ARTIST NAME";N$: GOTO 210 RUN 110 FOR R = I TO N: IF AS (R,I)=N$ GOTO 220 TO MAKE A REQUEST FOR AN ARTIST: TYPE # I 120 NEXT: IF Z > 0 THEN 200 ELSE 190 I TO MAKE A REQUEST FOR A TAPE #: TYPE # 2 130 INPUT"TAPE #;T$: GOTO 2 10 !NEW! TO MAKE A REQUEST FOR A TITLE : TYPE # 3 THE ORIGINAL DAN PAYMAR 140 FOR R = I TO N: IF A$ (R,2)= T$ GOTO 220 Classified Ad Space Available I TO MAKE A NEW LISTING GOTO 320 OR BEYOND: 150 NEXT: IF Z >0 THEN 200 ELSE 190 ONLY $5 per 40 character line including 160 INPUT"ALBUM TITLE";B$: GOTO 2 10 ======j Lower Case Adapter™ TYPE #?2 spaces & punctuation. 3 line minimum. ~ 170 FOR R = I TO N: IF AS (R,3)=B$ GOTO 220 TAPE #? IS Write Advertising Dept., Recreational 180 NEXT: IF Z > 0 THEN 200 ELSE 190 i ARTIST TAPE # TITLE SIDE # Computing, P. O. Box E, Menlo Park, CA 190 ?"SELECTION IS NOT LISTED": FOR D= I TO d E. FITZGERALD IS COLE PORTER I & 2 94025. TWO MODELS NOW AVAILABLE 450: NEXT: CLS: GOTO 40 IF YOU WISH TO SEE THE INDEX AGAIN, PRESS 'ENTER' KEY? 200 INPUT" IF YOU WISH TO SE E THE INDEX LCA·1 .- $59.95 AGAIN PRESS 'ENTER' KEY";X:CLS:GOTO 40 RUN AVAILABLE NOW! I For revision 6 or older Apple·]I* (with RAM configuration blocks). 210 ?"ARTJST","TAPE #","TITLE", TO MAKE A REQUEST FOR AN ARTIST: TYPE # I TAB(58)A$(R,4):Z=Z+1 :ON X GOTO 110,140, TO MAKE A REQUEST FOR A TAPE #: TYPE # 2 THE INTERNATIONAL 170 $49.95 TO MAKE A REQUEST FOR A TITLE : TYPE # 3 220 ? A$(R,I ),AS(R,2).A$(R,3), TAB(58)A$(R,4): Fo r rev. 7 or newer Apple·]I* (without RAM configuration blocks). TO MAKE A NEW LI STING GOTO 320 OR BEYOND: Z=Z+ I :ON X GOTO 120,150,1 80 MICROCOMPUTER Il One of Ihem is designed specilicaffy for your computer. ======• TYPE #?3 SOFTWARE No i~mpm. Tbe "one IInr~ IDr ,II Ap~lu " dul,n may requir. culling and nlderlng nine ALBUM TITLE? WILD IS LOVE * SUBROUTINE jumpers to adapt iltD yaur cam~uter. ARTIST TAPE # TITLE SIDE # DIRECTORY * Only one chip toremm from your computer [two lor thelCA·l "'). The "one board lor all KING COLE 30 WILD IS LOVE I , Applu" dulgn requires removing four chips Irom your computer. then plugging In I 230 ? IF YOU WISH TO SEE THE INDEX AGAIN, PRESS 'ENTER' KEY? i complex PC bmd. 240 CLEAR ONLY $28.95 + $2.95 post. i 250 N= Y 'Y MUST EQUAL NUMBER OF ! RUN DATA STATEMENTS TO MAKE A REQUEST FOR AN ARTIST: TYPE # I . 5000 entries, cross-referenced ! 26 0 DIM A$ (N,4) AVAILABLE AT COMPUTER DEALERS EVERYWHERE. TO MAKE A REQUEST FOR A TAPE #: TYPE # 2 by machine, O/S, application, t 270 FOR R = I TO N TO MAKE A REQUEST FOR A TITLE : TYPE # 3 ! DICE support software ENHANCEWARE" by 280 FOR C = I TO 4 vendor and program name. (diskette) $5.00 extra. TO MAKE A NEW LISTING GOTO 320 OR BEYOND: i 290 READ A$ (R,C) Phone or write for details. All 300 NEXT C, R ======MasterCard, Visa, Dan Paymar TYPE #?2 310 GOTO 40: CLS major credit cards accepted. and C.O.D. orders 91 Pioneer Place TAPE # 40 ! 320 DATA LINES START HERE \ shipped immediately. Durango. CD B1301 ARTIST TAPE # TITLE SIDE # IMPRINT SOFTWARE Telephone (303) 259-359B us · 420 South Howes St., Ft. Collins, CO f Dealer Inquiries invited. SELECTION IS NOT LISTED. 80521 . Tel 303 482 5574 ·Tr.d.m.'~1 01 Appl. Comput., Inc 16K WILL LIST 194 TAPES LEAVING ENOUGH (TH IS IS ON A TIMER LOOP IN LI NE 190 ! MEMORY FOR STRINGS AND DATA WHICH RETURNS YOU TO THE INDEX.) UK · 16 Milton Avenue, Highgate, London NS ·rel 01 3483998

iI 22 Recreational Computing, September-October 198 1, Issue 53 Recreational Computing, September-October 1981, Issue 53 i 23 , -~

lum development programs and in-service and also supervised the processing of Our goal is to distribute only those pro­ I training are the responsibility of LeRoy SOFTSWAP programs for each computer. grams which have some educational value How to Finkel, computer consultant, and of The committee consisted of Jim Love and which are as free of errors as possible Walter Smithey, math-science consultant, (PET), Brian Sakai (TRS-80), Dave Stone in both content and programming. The working under the direction of Tom and Bob Enenstein (APPLE), Marge actual quality of the programs in the col­ i Quinn, Director of Curriculum. Dr. James Fitting (Compucolor), and Pat Tubbs lection varies greatly, as does program ~ Start a Fee, Director of Media Services, offers (Atari). The chairpersons also conducted length. Each disk contains from 12 to 30 j assistance with hardware applications and informal demonstrations and evaluation programs, all for one system, but includes demonstrations. An extensive program to sessions during the summer. As we enter various su bjects and grade levels. Software interface computers and microcomputers our second year of the SOFTSWAP Donors complete a Preliminary In­ throughout the county's schools is being project, Leslie Grimm is the new chair­ ventory Form that identifies and des­ developed by Dr. Al Grossman, Admini­ person for APPLE; the other systems con­ scribes the program, and a Release Form strator of the Office of Information Ser­ tinue under the direction of the original that gives CUE permission to distribute Exchange vices. The entire project is under the ad­ Advisory Committee members. the program. The donor's form also asks ministration of Dr. Don Halverson, As­ Public support of the SOFTSWAP is whether the program is original, a modi­ sistant Superintendent for Educational encouraging. A large number of volun­ fication of another program, or an adap­ Support and Planning. This team ap­ teers continue to donate programs, time tation from a magazine or book listing. * l by Ann Lathrop proach by the county office staff, and expertise to this growing collection. The contributed program is put onto I coupled with the expertise and commit­ As new programs flow into the center a receiving disk where it will remain in its and Bobby Goodson ment of Computer- Using Educators, has they are routed to the CUE volunteers original contributed form as a permanent been crucial to the successful develop­ for evaluation, debugging and processing. record. Filled receiving disks are placed I ment of the Microcomputer Center. Finished programs are placed onto into our permanent archives after all of "What is different about Manufacturers of microcomputer SOFTSWAP dissemination disks which the programs on that disk have been pro­ ! hardware have also been generous in their can be copied without charge by anyone cessed. One donated program at a time is SOFTSW AP? Isn't it just support of the center. Tandy (Radio who visits the center. loaded from the receiving disk onto a another users' group?" he Microcomputer Center in Red­ and Canadian provinces, and from Shack) and Commodore (PET) provided The large number of requests from working disk and all subsequent versions ! wood City, California, is a gathering Australia and France. All have been in­ the first microcomputer systems and thus outside the San Francisco Bay area led to of that program will be stored on the Tplace for members of Computer­ terested in learning more about the initiated the support that has made pos­ the mail-order policies adopted this same disk until the program is finished I Using Educators (CUE) and visitors from challenging potential of microcomputers sible all su bsequent development. Each spring. The first catalog was published in and ready to be transferred onto the dis­ i"- sol'TSINAP other areas who enjoy sharing their ideas, as new instructional media. By support­ firm set up a complete system with mi­ the March 1981 CUE Newsletter and semination disk. We have approximately Recipe for a . experienced problems and expertise in this unique re­ ing the establishment of this unusual edu­ crocomputer, dual-disk drives, printer listed over 200 programs on 12 disks. 40 working disks, each with only one pro­ I enthUsiastiC,USING EDU­ source center. It's an exciting place to cational resource, the San Mateo County and cassette-recorder, all on long-term Four additional disks have been complet­ gram, being evaluated at any given time. Talce one OMI'UTER- spend an afternoon, a few days, or longer, Office of Education, under the leadership loan of the Microcomputer Center. A li­ ed, bringing the total number of programs At least two educators will review the grOUP of C F and the welcome mat is always out for of Superintendent William K. Jennings, brary of commercial programs loaned to in the SOFTSWAP to nearly 250. Anyone program on the working disk and make i CA.TORS, TY OFFICE 0 d educators who want to help with various continues its traditional role of develop­ the center by each firm includes educa­ who sends an original program on a disk w needed revisions. When they agree that it he one cOuN an establis CUE projects, to copy SOFT SWAP pro­ ing innovative educational programs in tional software and word processing sys­ ette as a contribution to the SOFTSWAP is finished the program will be removed Add nON w,th . leadeI'\UP, EDUCA . no"t"e grams, or who simply like to sit and talk California. tems. can request a free disk of programs in ex­ from the working disk and added to the I f with other microcomputer enthusiasts There has been no outside funding of Other firms providing equipment for change. Disks are also sold for the cost of current dissemination disk in the SOFT­ reput.tion foon pUBLIC DQ- i . collecttOn 0 L SOF-T who happen to drop in. Questions and the Microcomputer Center. The San the center induding APPLE, Atari, Bell & the disk, handling and postage. During SWAP. Another program from the re­ stir ,n a EDUCATION A CUE mem- answers fly back and forth, and frequent Mateo County Office of Education pro­ Howell and Compucolor. All of the sys­ the first three months of operation over ceiving disk is then loaded onto that MAIN tribUted bY arguments as to which answer is correct vides the space, maintenance and part­ tems are on long-term loan; the center 370 disks have been sent out, some going working disk and the evaluation process is WARE con ! loans of reflect the diversity of opinion and ex - time staff support as a service to educa­ has not purchased any hardware. CUE as far away as Buenos Aires, Singapore repeated. All finished programs on the bets, . h generous Corn- perience represented by the gro"Up. At tors in the county and throughout the members were of great assistance in con­ and Paris. dissemination disks are available for copy­ Season c~~PUTERS fromAPPLB, anyone time the questions may vary San Francisco Bay area. The active in­ tacting the various firms and securing ing by visitors. I M\CRO Ra d·, 0 Shack,I & Howe, \l from "What computer is best?" and "Can volvement of Computer-Using Educators their support and cooperation. Two forms are used in the evaluation modore, and Bel [ do the school budget and attendance on as co-sponsor of the Center has been the All of the manufacturers have been of program: Checklist for Microcomputer uColor, Cornp .th one this one?" to "How can I get this pro- other major factor in its success. helpful in maintaining the equipment in SOFTSWAP Procedures Program Revision and Programmer Reviw I ingredients 'Ill orga- gram to run off of our Corvus?" and CUE has grown into an organization good condition, despite heavy use in the What is different about the SOFT­ sian Sheet. These forms list common er­ combine a~ whO has ~tro~~mrnlt- "What is the difference between 3.2 and of over 1600 educators, with members center. They also provide new models as SWAP? Isn't it just another users' group? rors and problem areas which evaluators L\BRAR'tskills and a hrm of micro- 3.3 DOS?" in 40 states, 12 provinces and 12 foreign they are developed. This strong commit­ It is a users' group, but the primary dis­ are to check. Detailed notes describing nizattOna ducational uses Many answers are derived from do- countries. CUE members donate hun­ ment on the part of the manufacturers tinction is one of focus - SOFTSWAP needed revisions are made on the Pro­ ment to e it-yourself experience with the micro- dreds of hours of volunteer time to or­ has been another critical factor in the suc­ concentrates on the development of edu­ grammer sheet and the final reviewer cotnputers, . ture with computer systems, commercial packages, cess of the.center.- checks to see that all requested correc­ I~ ganize and participate in activities of the cational software. Most programs are ·ch m'x cRS' . I this n MEMB~ and SOFTSWAP programs which are center, including work on SOFTSWAP short, stand-alone instructional units. tions have been made. The finished pro­ spnnk e of CUE available to visitors. Other answers are programs, demonstrations of new equip­ Many are drill- and-practice exercises gram is described on a final Inventory manY \lOurs RWORK, VOI.-UNTEE ONE yEAR. found by consulting the resource file of ment and software, and the commercial Development of the SOFTSWAP written for the elementary school or for Form - SOFTSWAP and then added to for about names and addresses of people experi- software evaluation project. The SOFTSWAP began as an ex­ remedial work at the secondary level. the SOFTSWAP catalog. Newly devel­ Let marinate SOF1'SWAP.:. enced in almost all aspects of microcom- Many members of the county office change of instructional programs at the About one-third of the programs are oped programs are also listed periodically . Ids one d w,th Recipe Yle gladlY share every- puting. The books, journals and extensive staff cooperated in the development of Asilomar Math Conference in 1979. math oriented. Most games have been ex ­ in the CUE Newsletter. freely and. Educators reference files in the library provide still the Microcomputer Center and continue \ Vince Contreras, San Jose State Universi­ cluded since these are generally available These evaluation forms are not de­ c~o~m~p~u~te=r_-_u_s_'n_g______---..l more answers tQ visitors' questions. The to be active in its operation. The original ty professor, organized this first attempt. from other sources. Only a few utilities, signed to produce critical reviews for pub­ wherel people in the Center, both staff and visi- concept was presented by Ann Lathrop, The programs contributed by participants those of special interest to teachers, were lication but to provide a guide to be fol­ \~I- tors, are also a valuable source of infor- Library Coordinator, who continues to were deposited in the SMERC Library in on the first series of SOFTSWAP disks; lowed in polishing the programs for class­ mation and expertise. supervise the SOFTSWAP and the soft­ the spring of 1980. The first of the equip­ these also are readily available from many room use. Programs are checked for ac­ The Microcomputer Center was ware evaluation project. Assistance and ment being loaned to the center arrived user groups. curacy of content, clear instructions, Ann Lathrop is Library Coordinator at established just over a year ago in the Li­ support for the project was given by Dr. from the manufacturers just as school was Every program is evaluated by at trapping of input errors, etc. Certain the San Mateo County Office of Educa­ brary of the San Mateo Educational Re­ Curtis May, Director of Library Services, out. Interested educators worked through­ least two educators before it is added to a problems which frequently appear in con- tion, Redwood City, CA. sources Center (SMERC) as a joint whose commitment has been essential to out the summer to evaluate, edit and re­ dissemination disk and made available t Bobby Goodson is President o!Computer­ project of Computer-Using Educators the successful establishment of the cen­ vise the programs from the Asilomar Con­ for copying. Programs are edited for spell­ Using Educators, and Computer Resource and the San Mateo County Office of Edu­ ter. Visitors receive friendly help from ·Samples of the forms used for the SQFTSWAP ference, ing errors, inaccurate or incomplete in­ are available from the authors at the San Mateo ! Specialist at the Cupertino Union School cation. Visitors have come from through­ Janice Marshall, Library Assistant, and CUE members served as an Advisory structions, errors in factual content, pro­ County Office of Education, 333 Main St., District, Cupertino, CA. out California, from many other states from her staff of student aides. Curricu- Committee for the Microcomputer Center gramming errors and other problems. Redwood City, CA 94063. 24 Recreational Computing, September-October 1981, Issue 53 i! Recreational Computing, September- October 1981, Issue 53 25 ,! .-...... --~---~------.....------,,------,------

tributed software could be reduced or 7) Do you make negative remarks to or may preview the software and are invited i eliminated if donors would check the fol­ about the student? Sarcastic state­ to help with the review process. However, IProgramming Problems & Solutions by Jim Conlan I " lowing: ments can be discouraging. We re­ this software may not be copied. 1) Does the program run with relatively move comments like "Boy was that Our goal is to make selected software few problems? (Unfortunately, we dumb," "Stupid," "Dummy," etc. available for each microcomputer system I; receive many programs which do not 8) Do you provide hints and/or even­ in the center in order to demonstrate the ! load/run at all.) tually give the user the correct an­ special features of the system We also Some Solutions on page 28. If the chairperson of the society amoebas. At the end of 2 hours, there ! 2) Does the program trap input errors? swer? We usually allow only 3 or 4 want to give the potential user some idea knew beforehand how many leftovers were 4 amoebas. At the end of 3 hours, 9 Does it crash if the user. inputs nu­ incorrect responses before providing of the range and quality of materials Modular Arithmetic there would be, then precautions could there were 8. At the end of 4 hours, there meric responses when the computer either a hint or the correct response, being pu blished in various su bject areas. or How to Cook with Leftovers be taken to avoid loud arguments over were 16. This was enough to harvest, so Finally, we will provide the opportunity i is expecting alpha, or vice versa? often with some instruction of ex­ Leftovers are interesting, useful and the last few pieces. What is needed is a 13 amoebas were put away. There were What happens if the user hits an planation. Exceptions are programs for educators to preview a wide variety of computer program that takes as input the only 3 left. After S hours the 3 had software before making purchase deci­ valuable things. The leftover Thanksgiving unwanted ENTER/RETURN? When which are tests or timed drills for turkey makes tasty sandwiches. Leftover number X of pieces of gum, the number grown into 6, and so on. there is an input error, is the com­ accuracy. sions. Since it is currently very difficult Y of members present, and then prints The Biology Department would like to find reliable critical reviews of comput­ money makes a nice savings account. ! puter response clear and simple? 9) Is the content accurate? Are the defi­ Leftover string makes a nice ball. Left­ out the number of leftover pieces. a computer program that prints out the er software, and because many teachers "Input error, redo from the start" nitions and/or explanations simple over rags make nice rugs. Leftover num­ number of remaining amoebas at the end is not helpful to the novice. and straightforward? Do they corre­ prefer to make their own evaluation be­ Hint for Gum Runners of each hour. If a halVest has taken place, ! fore purchase, we believe that this will be bers make nice arithmetic. i 3) Are all the words spell ed correctly? spond to the material in the more Well, pass out the gum Let's see, the number to be printed out is the num­ an especially valuable selVice. The arithmetic of leftover numbers i 4) Are the instructions and other infor­ frequently used texts? how many pieces of gum are there? ber left after the harvest. We are also developing a collection of is called modular arithmetic. The theory mation easy to read on the screen? 10) If it is a drill-and-practice program, of leftovers is a highly developed science. Looks like the number of pieces of gum software to demonstrate administrative ! Is it formatted to avoid split words at do examples come up in random or­ this time is X = 23. (We just made that Hint to Germ Harvest I applications of microcomputers. We will You have used it many times. Clocks use the end of a line? It is best to avoid der? Are there enough problems or leftover arithmetic. up.) How many gum chewers are there? It Those tiny devils keep splitting in crowding and to clear the screen at questions that the student will not preview and display software designed for two. That makes twice as many. Whatever ! appropriate intervals. Instructions have all the same examples if they school administrators, including word MOO 12 is left after the harvest will double during should be written at a reading level run the program again? I.f it is appro­ processors and data base management the next period. appropriate for the intended user. priate, does the student have the op­ programs. We are also especially interest­ TIME 0 LET Y= I. This is the initial 5) Is the positive reinforcement for the tion to return to the beginning of the ed in potential uses of this type of soft­ ! GQ)C9cgQ)CDQ)Q)e)e)~0) number of amoebas. Y < 13 so correct responses more interesting ware in special education programs. exercise and try it again? Throwaway the 12. there are not enough to harvest. 1 that the negative reinforcement for Finally, we want to be sure that the As part of our commitment to en­ l G Q) Two left oved i errors? Graphics in most "Hangman" program su bmitted is truly an original couraging the development of good criti­ TIME I Y=2*Y=2. Y has doubled, but type games, for example, are usually creation of the author. If it is an adapta­ cal evaluations of microcomputer soft­ 14MOD12=2 Y < 13. There are not enough to Figure 1. harvest yet. !1 more exciting when the user loses tion from another program, from a book ware, the Microcomputer Center is a and is "hanged." Students will often or a journal we want to be aware of that participating member of MicroSIFT, a TIME 2 Y=2*Y=4. Y has doubled again. i deliberately miss a problem or a fact. We will request the author's permis­ Northwest Regional Educational Labora­ If you start a job at noon and it looks like Y = 7 gum chewers. (we made Y < 13. There are still not word in order to see a rocket ex­ sion to include the program in our col­ tory project funded by the National In­ takes 14 hours, then what time will it be that up, too.) Let's pass out the gum. One enough to harvest. plode, a boat sink, etc. It is best to lection. If we discover that a SOFTSWAP stitute of Education. The objective is to when you finish? The clock has only 12 for you, and one for you" and .... We TIME 3 Y=2*Y=8. Y < 13. No harvest. try to provide strong encouragement produce and disseminate a high- quality numbers. The leftover is 14-12 = 2. You can keep passing out gum in groups of ! program is actually an infringement on TIME 4 Y=2*Y= 16. Y>= 13. There are for doing a task correctly and yet evaluation instrument and to publish re­ will finish at 2 o'clock. Of course, there seven until there is not enough to pass someone else's copyright, we remove it now enough to harvest. Take avoid over-praising. It is also better views of computer software evaluated in are 24-hour clocks. Those repeat after 24 out another group of seven. from the dissemination disk. away groups of 13 as many I to provide several responses for both The most exciting programs we re­ terms of the criteria developed. CUE hours. Short-wave radio and sea-going times as possible. Y=Y-13=3. l correct and incorrect answers - a ceive are the creative ones that do more members, under the coordination of the people use this system. You are using a , Germ Harvest Since Y < 13 now, no more can little variety adds a great deal to the Microcomputer Center staff, have already MOD 12 modular arithmetic system to than just put workbook pages and drill be harvested. ~ program problems on the screen. Contributed completed the first round of MicroSIFT tell time by a 12·hour clock. MOD 24 The ComputerTown College Biology 6) Have you included REM statements software is improving as educators be­ program reviews. would be used with a 24-hour clock. Department has an experiment underway. TIMES Y=2*Y=6.Y<13.Noharvest. ! as needed? They make it easier to come more sophisticated users and pro­ Leftovers can cause serious social They are growing amoebas. You've etc., etc. (Solutions on page 28.) use a program effectively. It is espe­ grammers. Newer programs are often Summary and political problems. Consider what probably seen amoebas under a micro­ I cially helpful to include statements more challenging to the student user and Any new project is accompanied by happens when 7 serious gum chewers try scope. They're squishy, round, little ! telling the teacher how to modify make better use of the unique capabilities often unexpected and urgent needs. More to divide 54 sticks of gum The 5 leftover devils. Amoebas make other amoebas in Some Old Business , word lists, problems or other entries. of the computer. We are especially than the usual number of critical needs pieces are a definite problem Wars have the most simple and unromantic way. Ed Coudal sent a nice solution to the l pleased when we receive donations of seem to surface with an educational been fought over less. Each amoeba splits itself into two reversal problem in the July/August this type and take special pride in being microcomputer project - perhaps because Leftovers are everywhere. You may amoebas. This happens quite regularly for column. The problem was to take a 20- ! able to make them available to other there is apt to be a lack of readily avail­ have heard the story about the computer the amoebas in the experiment. In fact, character line, and invert it. His solution i teachers through the SOFTSWAP. able support resources. The partnership programmer at a certain well-known it happens every hour, on the hour. is written in North Star BASIC which • of CUE and the San Mateo County Office bank who noticed that numbers like The amoebas are harvested occa­ uses the '+' as a concatenation operator. I of Education has created the Microcom­ $3.254 often occur. The observant pro­ sionall y, right after they have split. The Here is his solution. Evaluation of Commercial Software puter Center to meet many of these grammer noticed that banks worked only harvested amoebas are divided equally The newest project in the Microcom­ needs. We have provided educators with a to the nearest cent and never in fractions among 13 different bottles. The harvested 100 DIM A$(20), AI$(2I) !, puter Center is the development of an ex­ place to see and try various microcom­ of a cent. He wrote a program to put the amoebas are not allowed to split anymore 105 AI$=" " emplary collection of commercially puter systems where other educators who leftovers in his own account. The poor (we guess that the Biology Department 110 INPUT A$ produced educational software. We have understand their concerns are available. fellow was caught only because the left­ knows how to remove the splitter from 120 FOR 1=20 TO I STEP -I Pick off contacted publishers of microcomputer We have created a demonstration site for overs grew so large that his account at­ amoebas). Any leftover amoebas are 130 B$=A$(I,I) the tail of A$ software with requests for review copies commercial software, where teachers can tracted attention. allowed to stay and keep on growing. 140AI$=AI$+B$ GlueitontoAl$ of their educational packages. To date the "try before they buy," and where they At first there was only one amoeba. 150 NEXT response has been very encouraging. can develop the ability to do critical and Gum Runners At the end of 1 hour, there were two 170 !AI$ PrintAl$ Many publishers appear to welcome the objective evaluation of software. We are The ComputerTown Gum and Social opportunity to put their materials on dis­ providing free, educational software and a Society gathers on the third Wednesday play for evaluation. CUE members are way for teachers to exchange their own of every other month for a tasting party. previewing and evaluating this software programs with others. We hope we have The members of the society taste and 80080000000000 I during the summer and the project will created a model that will work in other evaluate the finest of the world's gum ~ Harvested Bobby Goodson, one of the moving forces of continue throughout the coming school areas and thus will play an even more sig­ The leftover gum has occasionally been a ! Computer· Using Educators, possesses a wealth year, with tentative plans to publish a col­ nificant role in developing uses of micro­ problem since it is so hard to divide Leftovers Figure 2. of information about educational software. lection of reviews. Visitors to the center computers in education. • evenly. tl i 26 Recreational Computing, September-October 1981, Issue 53 I Recreational Computing, September-October 1981, Issue 53 27 ,j '-.------.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Solutions to Programming 40 Z= X- INT(X/Y)'Y then the computations in lines 40-60 Problems 50 REM " PRINT REMAINDER" will be done 1000 times. It takes some ~ ~ 60 PRINT Z time to perfonn each BAS IC state­ Solut ion to Gum Runners # 1 ment. An estimation to perfonn l Solution to Germ Harv est # 1 lines 40-80 could be in the order of I ItllU ~ lr II ~ l(3lr () ~ Ie I() ~\ IP IU lr II ~ 1(3 I One way to solve this problem is 10 REM " Y IS NUMBER OF a second. A thousand seconds is nearly to pass out the gum just like 5 -year ~ ~ AMOEBAS" 17 minutes. That is too long to wait! oids do. Just keep going around the PROGRAMS LISTED BELOW ARE ON DIS K: ...... 20 Y=I Observ e what happens if we let I~""'~""'~""'~""''' ~ ~ ~ ~~~I circle until there's n ot enough gum to 30 REM "Y DOUBLES" the amoebas grow aw hile before we go around again. A program to do this: 40 Y=2'Y harvest the excess. [f the· amoebas I Now Selling Atari, PET, TRS-80 Software ~ 50 REM "GO PRINT IF NO grow for 5 hours, there will be 2 t 5 = 10 X=23 HARVEST'· 32 of the little rascals. If we now har­ ri Atari Pet TRs.ao ~ 20 Y=7 ADVENTURE INTERNATIONAL AVALON HILL GAME COMPAN Y BIG FI VE SOFTWARE 60 IF Y< 13 THEN 100 vest groups o f 13, we are left with 6. lW ~ 30 REM "TEST IF THERE IS ~ Advenlureland (cass) $1 4 95 no... $12.74 8·1 NUClea r Bomber (cass! S15 00 no... $12.77 Super Nova (cass.) ... . $15.95 no... $13.5 ••' 70 REM " HARVEST" This is just the am ount we would have Pirate S Adventure Icass) $1 4 95 no... $12. 74 Mid way Campaign (c ass ) $1500 no... $12.77 Galaxy InvaSion (cass. ) ...... $1 5.95 no... $13.5. I ENOUGH FOR Y PIECES" 80 Y= Y- 13 ~ MISSion Impossible (cass) $1 4 95 no... $12. 74 No Atla ntiC Convoy Rai der Icass) $ 15 no... $12. 77 Attack Force (cass. ) ...... $1 5.95 no... $ u.s. ~ 40 IFX < YTHEN 11 0 had if we had harvested at each step. I• Voodoo Castle (cass ) $1 4 95 no... $12.74 Nukewar (c ass) $1500 no ... $12.77 CosmiC Flghler (cass. ) ...... $ 15.95 no... $U.5. 90 GOTO 60 We have avoided all those in -between TheCounl (c ass .) $1 4 95 no... $12. 74 COn f 1I ct250C(cass) $1500 no... $12.77 Meteor MIssion It (cass. ) ... $1 5. 95 no ... $13.5. ~ 50 REM " PASS OUT Y PIECES - ~ Strange Odysse y (c as s.) $1 4 95no ... $12.74 PlaneI Mlners(cass) $1500 no ... $12.77 ., 100 PRINT Y steps. That should speed things up. DECREASE X" ~ Mystery Fun House (c as s.) $ 14 95 no... $12.74 Computer AcqUire (cass) $2000 no... $16.97 BRODERBUND SOFTWARE ~ 110 GOTO 40 Here is a program that attempts to Py ramid 01 Doom (c ass ) $14 95 no... $12.74 Lords of Karma (cass ) $2000 nO... $16.97 I 60 FOR W= I TO Y Ghost Town (cass) $14 95 no... $12.14 Galacllc Tri logy (disk) 539 95 no... $33.9. use this technique. The logic is OK, I Savage Island I (cass.) $1495 no... $12.14 Galactic Empire (cass.) . .$1 4 95 no... $12.6. ~ 70 X=X - I Savage Island II (cass ) $1495 no... AUTOMATED SIMU LATIONS Galactic Trader (cass.) . .514.95 no... Once again, the first solu tion can but there is a practical difficulty. Can $12.74 $12.6. ~ 80 NEXTW ~ Angle Worms/Crolon Dlv (cass.) 5995 no... $ •• 54 Introductory 3-Pack (disk) $4995 no... $ 3 9 .9 7 Galactic RevolUtion (cass). $14.95 no... $12.... be improved by perfonning a division you see why this perfec.tly good pro­ ~ Deflection (cass) 995 no... $ • • 54 (Rescue. Morlocs. and Oateslones) Tawala 5 Last Redoubt (cass.) 519.95 no... $ 16 .9. I 90 REM "GO CHECK IF DONE" Mountain Shoot (cass) 5995 no... $ • • 54 Rescue at Rigel (cass ) $2995 no... $ 2 5 .4 7 instead of subtracting 13 many times. gram will not work? r:.. 100 GOTO 40 • Sunday Goll (cass) 995 no... $ • •54 Temple of Apshal (cass I $3995 no... $ 3 3 .91 Lines 50-90 need to be changed. In­ I GalactiC Empire (cass) 51995 no... $1..... Helilire Warnor (cass) $3995 no... $ 33.97 OATASOFT ~ 110 PRINT X StarTrek35(caSS) 51495 no... $12.14 Starileel Orion (cass.) $2495 no... $21 .27 lagO(dISk) . . -- . $2495 no... $ 21 . 1. stead of su btracting 13 some num­ 10 INPUT X Lunar Lander (cass) 51495 no... $ 12.14 InvaSion Onon (cass ) $2495 no... $21 .27 Foolbalf ClaSSICS (disk) .. 524.95 now $ 21. 1. 120 END ber of times you can find how many ~ Morloc s Tower (cass.) $1995now $ 16 .9 7 Arcade·aO(dlsk) 524.95no... $ 21. 1' I 20 Y=I riIII ARTSCI Dateslonesol Ryn (cass) $1995 no... $16.97 lago (cass) .... 519.95 now $ 16.9' copies o f 13 are contained in Y. For 30 REM DOUBLE Y,X TIMES I• Poker Solitaire (cass.) 51495 no... $ 12. 7 4 Foolbafl ClaSSICS (cass.) $1995 no... $16.9. This program has some good example, if Y=16, then Y/ 13"'1.23. Gomoku(cass) $1995no $16.... Arcade·80(cass) .. $1995no... $16.9 . ~ points and some bad poin ts. The good 40Y=2tX ReverSI (cass) "$1995 no: $...... PERSONAL SOFTWARE Sigmon (COLOR) (cass.) $2995 no... U5.3. ~ The number of copies of 13 in Y is 50 REM HARVEST GROUPS OF 13 ~ Cypher Bowl (cass) 529.95 no... $25.44 VlslCalc (diSk) $199.95 no ... $1 6 7.77 SECS (COLOR) (c ass) . 52995 no... $25.38 • point is that it follows closely the way Checker King (cass.) $1995 no... $16.97 I given by the expression INT(Y/ 13). 60 Y=Y-INT(Y/13)' 13 ~ AUTOMATED SIMULATIONS Gammon Gambler (cass.) $1995 no... $16.97 ~ that 5 -year olds pass out gum The bad You can get the remainder by sub­ I• Rescue at Rigel (c ass) $29.95 no... $ 25.44 MlcfoChess (cass) $1995 no... $'6.97 ACORN SOFTWARE points are many. First of all, lines 60, 70 PRINT Y Star Warrior (cass.) 539.95 no... $33.94 Bndge Par1ner (cass) $1995 nO... $ 16.91 Invaders From Space (disk) $20.95 no... $ 17. 7. ~ tracting this many copies of 13 from ~ InvaSion Onon (cass.) $2495 no... $21.24 Time Trek (cass.) $1995 nO... $ 16.97 Duel·N·Drolds (diSk) $2095 no... $1 7 . 7 ' 70, and 80 do nothing but subtract Y Dateslones of Ryn (cass) .....$19.95 now $16.94 Pinball (disk) .$2095 no... $ 17.7 ' y. The remainder is Y-INT(Y/13)' 13. Suppose X=IOOO. How big will ~ Pigskin (disk) $20.95 no... $ 17.1. I from X. We could replace lines 60-80 r:.I AV ALON HILL GAME COMPANY UNITED SOFTWARE OF AMERICA Quad (disk) $2095 no... $17.78 2 t X be? Will any computer be able to with a single line: I• Empire 01 the Overm lnd (diSk) $35 .00 now $29.14 KRAM (disk) . .599.95 no... $ .... 97 Basketball (disk) .. . 52095 no... $17.7. Ch anges for Solution to handle such a number? It is not very Conlllcl 2500 (cass.) .. . $15 .00 now $12.14 Super KRAM (disk) .5 175.00 no ... $148.17 Gammon Challenger (diSk) 52095 no... $17.78 ~ 60 X=X-Y ~ Empire 01 the Overmlnd (cass.) 530.00 now $33.94 Request (disk) . . .. 5225.00 no ... $'91.2 7 Everesl Explorer (disk) 520 .95 no... $17.7. ., Germ Harv est # 2 likely since 2 t 1000 is about equal to This would pass out Y pieces all at ~ TanktlCS (c ass.) . OATASOFT$24.00 no... $20.44 Thinker (disk) ...... $495.00 no ... $420.77 SuperScnpt (disk) 529.95 no... $25.3. I 50 REM "HARVEST" 10 t 301. That's a I followed by 301 Space Intruders (cass.) .$19 .95 no... $ ••• 91 System Savers (cass) $14 95 no ... $12." once. The program would run much Atan Mailing List (disk) ...... 524.95 no... $21 .24 All MICRO-ED .10% 0" Lis. Invaders From Space (cass) $1495 no ... $ 12." zeros. I All Microcomputer Workshops 15% 0" Lis. D"el N D'o,d< (0'« I S1495 $ . 2 . . ~ It 60 Y=Y- INT(Y/1 3)'13 At an Character Generator (disk) .s19.95 now $1...... " "" no.... ~ faster with this change. would still _____ delet e line 70 70 We ca n salv age so mething from ~ Text Wizard (disk) ...... 599.95 flO'" $ ....44 Pinball (cass) 514 .95 no... $12.6. be quite slow when X is a big number ~ At an Character Gen (cass.) ... 515.95 no... $13. 54 Pigskin (cass ) 514.95 no... $12.6 . I 80 PRINT Y the last approach. The computer can LeStlck sa995 $ 33... SoecialBirthdaySale Quad(cass) $1495no... $ . 2 .• • and Y is small. In such a case, it might r:.I ' ...... no.... FotfWO-YHr.OIdCompiJferIheni Basketball (cass) 51495 no... $12 ." 90 GOTO 40 handle 2 t 16=65536 without any dif­ be necessary to do thousands of I• ON·LINE SYSTEMS To oelebrate our daughle< MeIOOy's second borthday. we .re oIIenng Gammon Challenger (cass ) 51495 no... $ 12." ficulty. We could break X= 1000 up HI·RES Adv 112 · Wiz & one 01 the best games we've _ anywhere aI • speaat proce Everest Explorer (cass I 51495 no... $12.6 . ~ subtractions in line 60. Your computer 100 ----/Tdel et e l ines 100 l.~ Princess (disk) . . .532.95 (ICWf $ 27.... ~.::~o:' · :o~t =:-;:~=:..:=r~~ All Adventure InlernallOnat 15% 0" LI. . ., . and 110 into chunks of 16 . is fast, but such things do take time. 110 yea.s old 10 pnmary g.ades It runs..., IheAppie II ' plus tApplHo/l') All Automated Simutations 15% 0" LI. . The program will look like this: ~ PERSONAL SOFTWARE andneedsC8KplusadlSkdnveltllstslorS2J,*,bIA~YOUNY'Happy All Avalon Hilt 15% 0"LI • • I~ Here is another 'ap proach which is r. t~~~~~,t~II~k~) (cass.) S~~~.~~ flOW" $$'~:: =: t:l:rtCyoucenh a ye ~ Ior S 1899 We""""'you"IIk.~ We All Hayden 15% Off LI •• Now that you have seen these two . no... All Microsoft 15% 0 " LI.. ~ based on division. M oCh (ICWf solutio ns, can you write a program 10 X=IOOO:REM X COUNTS THE Icr ess cass.)...... 519.95 $ 1 ..... that allo ws the user to input the num­ HOURS ~ UNITED SOFTWARE OF AMERICA Solution to Gum Runners # 2 S' ''',,,IIAd, eol,,e (di,k) .....•2 4.95 _ $2'.24 Apple ~j ber of hours X that have gone by and 20 Y=I: REM Y WILL COUNT 3·0 Supergraphlcs (disk) ...... $39.95 flOW' $33.94 ~ The quick way to find out how 3·0 Supergraphlcs (cass.) .$39.95 no... $33. ... then prints the number of amoebas AMOEBAS I many 7'5 there are in 23 is to divide 23 remaining at that particular time? 30 REM 'SET THE NUMBER Z OF ~ VERSA COMPUTING ~ by 7 ge tting 3.28574286. The integer Mlnd·Bogglers I (disk) ...... $ 19.95 now $16.94 I The most straightforward way to GROWTH PERIODS' ~ Mlnd·Bogglers I (cass.) $15.95 no... $13.54 part o f this division is 3. This tells us do this is to add a counter to the previ­ 40Z=16 r. VersaWriter Graphics Tablet ... $300.00 now $254.44 that there are three 7's in 23 with a bit Hidden Words ...... $17. 50 no... $15.44 Gorgon . 539.95 no... $33.99 VersaCalc .. $100 .00 no... $ .... 99 ~ ous program and print out the value SO IF X < 16 LET Z= X lW Spatial Relations . . .. $17.50 no... $15.44 Word Star . . $375.00 no ... $2'9.00 Hebrew .... 560.00 no ... $50.99 ~ left over. To find out how much is of Y when enough hours have go ne by. 60 REM LET Y GROW FOR Z ~I Word·Scramble .. SI5.00no... $13.54 Mall Merge ... $ 125.00 no ... $106. 19 All Serendipity .. 15% 0"LI••• left, we subtract 3*7 from 23. There Preschool Fun $15.00 no... $13.54 Super Son . . .. $200.00 nO ... $1.9.99 Sneakers...... 15% 0" LI.. I HOURS r:.I Fastgammon (cass.) $19.95 no,., $1..... VlslCalc 3.3 .$200. 00 no ... $169.99 All Sybex Courses 15% 0" Lis. ~ are 2 remaining pieces. In BASIC, the • Assembler (cass. ) .$24.95 no,., $21.14 Wurst of Huntington Computing ...... , ..$19.99 Wm at the Races. 539.95 no... $33.99 Solution for Germ Harvest #3 70Y= 2tZ*Y I computation is perfonned by : 6502 Disassembler (cass.) .S11.95 no... $10.14 Nibble Express ...... 512.95 no... $11.99 DISk Prep $25.00 no... $21 . 19 ~ 10 Y=I : REM Y IS INITIAL AMOEBA 80 REM HARVEST THE EXCESS ~ 6502 Disassembler (disk) .... 5 14 .95no... $12.64 SoftPornAdvenlure ...... $29.95no ... $25. 39 PlE Chip ...... $60.00 no... $50.99 ., ~ Tank Trap (cass.) .511.95 no... $10.14 Time Lord .. $29.95 no... $25. 39 We maintain a huge inventory of Apple software and I 23-INTI23/7)'7 = 2 NUMBE R 90 Y= Y - INT(Y /13)'13 I';i Tank Trap (disk) .514 .95 no... $12... French Hangman .$2995 no ... $25.3' hardware. Call us toll tree (outside Calif.) for the 20 Z= 0: REM Z IS THE COUNTER 100 REM ROUN D Y TO INTEGER r.. Tafl Trek (cass.) .$11 .95 no ... $10.'4 Allcla·Sp. bilingual reader .52995 now $25. 39 latest programs. We also stock a large supply 01 / as Fonh (disk) ... . .$79.95 no... $61.... H&H Stock Trader 5190.00 flOW' $161.49 computer books. Visit us in person at our new 3300. ~ 3 - Th,es e are 110 Y= INT(Y+.S) Starbase Hypeflon (disk) 522.95 no... $19.44 Grow (CIA) .$35.00 no... $31.49 sq u.are foot store at 1945 South Dairy in Corcoran, original 30 INPUT X: REM X IS NUM BER OF lW ~ Name Thai Song (cass.) 51495 now $12.... Spelling Bee ... 15% 0" LI.. CalIf. • pieces t the lefto vers HOURS 120 REM DECREMENT THE HOUR ~ three 40 Y=2'Y: REM Y DOUBLES COUNTED f ull gro u ps 130 X=X- Z of 7 50 Y=Y-INT(Y/ 13)'13 60 Z=Z+I : REM INCREMENT HOUR 140 REM CHECK IF DONE ~ Call Toll-Free 800-344-4111 (Outside California) ~ i The program for this second solution: COUNTER I SO IF X > O THEN 40 160 PRINT Y 70 REM TEST IF DONE ~ HUNTINGTON COMPUTING, SUPER DISCOUNTS W,-" la ~e Masle.Cara 0' VI5A dnc..luOe c..a.o ~ I 10 REM ' ·X PIECES OF GUM AND 80 IF Z< X THEN 40 lW Post Office Box 787 " ana exp.ra!,on dalel Cahlorn a reS,denlS ~ ~ Corcoran California 932 12 l :!l aoe 6 lax tnCluoe S2 00 lor postage ., i Y CHEWERS" 90 PRINT Z Yet Another Method to Harvest Germs , 20 INPUT X,Y There is one last method that uses p:.; Order by Phone 800-344·4111 .C1~ SO FTW A R E • '0"'0" '"' ""w", "',' 5,", '" "e, ~j ~ In California (209) 992-5411 I .... ~ c.a a oc; Proces 5uO)eCl wc..hange ~ 30 REM' 'COMPUTE THE REMAIN­ The® main problem with this solu­ an important and famous bit of num­ ! tion is that if X is big, say X=IOOO, ber trickery. Pierre Fermat discovered ! DER'· ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ i i 28 R ecreational Com p u t ing, September· October ~ 98 1 , I ssue 5 3 j '- -, ~ I , David Beard Solutions continued from page 27 ~ Games and J.

and proved in the 1600's that for any I prime number P, 2 t (P-l) has a re~ •! * KNOCK KNOCK! TIN..,. LISP RERD..,. mainder of 1 when it is reduced by Who's there? multiples of P. In our present problem, ! KNOCK KNOCK this means that 2 t (12) leaves I after Computer Sam UHO/S THERE? ORRNGE harvesting groups of 13. Put another Sam who? ORRNGE UHO? way, after 12 hours there is only 1 I ORRNGE YOU RERD',' VET? Sam person who knocked last time. JOK£5 am?eba left. After 24 hours, there is Knock-Knock Jokes agam only I amoeba left. TINY LISP RERD~' How many 12's are there in 1000? Listing One JOKES INT(I 000/1 2)=S3. After 12 *S3=996 ! « ORRNGE DRRNG.E YOU RERDY 'r'ET?) hours there is again only 1 amoeba i LISP version of (BOO BOO HoO HOD!» left. In the remaining 4 hours, the LISP is a language which many people use to experiment "Computer Knock- Knock Jokes" ! TINY LI SP READY amoebas will grow to 16 and, after one I with Artificial Intelligence. If you are interested in AI, or more harvest, there will finally be 3 would just like to see LISP in action, or if you enjoy corny The "etc." is a bit more complicated. Take a look at the first *"'''' JOKES "''''''' TELL JOKES ( ELI ZR ELIZA DEAD PROGRRI'II'IER. KNOCK" KNOCK! left. jokes, then read this article. The author provides a BASIC and "knock-knock" in the sample run. The user types in "KNOCK ( JOSE JOSE CRN 'IOU SEE. . . . ) ! KNOCK" to call the function KNOCK ("GOTO I 00" in WHO / S THERE? a LISP version of the same program. Compare them, and see ( ORRNGE ORANGE mu READ~' YET? ORRNGE I BASIC). "WHO'S THERE" is the argument passed to ASK and ( 800 800 HO~ HOD.' ) which intrigues you the most.' - The Editor ) ORANGE UHO? ! printed out by the computer. "ORANGE" is the value of ORRNGE 'r'OU RERDY YET? Final Solution to Germ Harvest ome time ago I heard rumors of a voice I/O terminal be­ INPUT at both places in the function. "ORANGE WHO?" is "''''* FORGET *"'* KNOCK! KNOCK! 10 INPUT X the value of the function APPEND. "ORANGE YOU ... " is ( NFUN WHO./S THERE ing demonstrated at a trade show. It seems that two com­ ( ) 20 REM * FIND REMAINDER OF X the value of the second ASK. The second CONS adds the item BOO puters equipped with the terminals were telling each SETQ JOKES NIL NIL ) BOO WHO? WHEN REDUCED BY 12 * , S "ORANGE" on to the beginning of the list "ORANGE YOU I other knock-knock jokes. At that time I was looking for sim­ 800 HOD HOD.' 30 X=X-INT(X/12)*12 ... " and returns this new list to the first CONS, which adds it *** KNOCK **'" ple problems to exercise a brand new, home-brew LISP inter­ (" NFUN TINY LISP RERDY 40 REM * LET THE AMOEBAS preter, and the idea of the knock-knock jokes intrigued me. on the beginning of the list JOKES. Finally, the function ( ) ~ COND GROW X HOURS * This article presents the program that resulted (Listing One), SETQ assigns this new joke list to the symbol JOKES. A literal (" ( ASK 50Y=2tX along with a very nearly equivalent program written in TRS­ English language equivalent for KNOCK would use at least ( ./ UHO./5 THERE? ) ) Listing Two 60 REM *HARVEST THE EXCESS ! SO Model I Level 2 BASIC (Listing Two). four levels of subordinate clauses. The BASIC equivalent uses SETQ JOKES AMOEBAS * ( CONS BASIC version of This is not a "LISP versus BASIC" article. The TRS-SO only one level of nesting, but uses five assignment statements ( CONS INPUT 70 Y=Y-1NT(Y/13)*13 program was written to help explain the operation of the LISP to LISP's one. Assigning intennediate results to symbols ( RSK "Computer Knock- Knock Jokes" 80 REM * ADJUST Y TO BE I ( APPEND functions by presenting a familiar equivalent. Taken by itself, simplifies the grammar enonnously, both in the BASIC ('/ UHO?) INTEGER * It 19 REM ----- TELL KNOCK-KNOCK JOKES it's a pretty poor piece of programming. The mere fact that program and in my natural language explanation above. INPUT) ) ) 28 REM ----- TRS-SO NOD 1 LEVEL II 16K 90 Y=INT(Y+.5) one can write a short program similar to one in a radically also leads to a proliferation of symbols, which is one reason JOKES»» J8 REI'I ----- 80 11 83 DJB 100 PRINT Y ! 40 CLEAR 12089 why the BASIC program uses numeric subscripts and pointers. different language says a great deal about the power and ver­ "'** TELL "'** 180 R£I'I ----- FORGET It would be difficult to think of several hundred names for ( FUN 110 0111 J$(255.2) satility of Microsoft's BASIC interpreter. ( A ) Run this final solution with an i parts of a joke without getting downright silly. Notice that 120 JI(:!, :!>="" The first thing our program needs is a list of jokes. The DO 130 J$(1., 2)="" input value of 1000 for X. Compare function "FORGET" in Listing One means roughly, "set the there is not a single numeric character in Listing One. This ( COND 140 P=1 the time it takes to print the solution I symbol JOKES equal to an empty list." The NIL symbol is a trade-off between complexity of grammar and the profusion ( ASK 150 STOP compared to that for the previous pro­ : of numerical pointers is a fundamental difference between ( ./ KNOCK! KNOCK! ) ) 2ge REI'I ----- KNOCK sort of general negative in LISP. It means, among other things, ( RSK 210 RI="UHO./S THERE?" grams. This one runs almost as fast as "no," "none," "false," ."empty," "the end," and "none of the LISP and the major procedural languages. I suspect that a (CARRR» 2213 G05UB sea when only one amoeba splits into two ! above." Lines 10 through 150 of Listing Two accomplish choice between the two has more to do with personal taste ( PRINTLIST 230 IF 1$="" THEN Gom 2ge ( CDRR R ) ) 24.0 J$(P.1>=1$ amoebas. • much the same thing, except that we must be more specific than with the application involved. ( PRINT) 250 R$=Is+" NHO?" about the type and number of items we want to store. Line The function TELL is more straightforward. In LISP one ( PRINT) 260 GOSUS 500 ( SETQ A 140 sets a pointer to the current "top of list." There are no di­ enters "TELL JOKES", in BASIC "GOTO 300". The DO in 270 Js(P, 2)=1$ I (CDRR» 288 P=P+1 Listing One corresponds to the FOR-NEXT loop in Listing (CORR») mension or type statements in LISP; however,the symbol used 290 STOP EDUCATIONAL SOFTWARE for our joke list must be assigned some specific value. There is Two. DO will continue to evaluate the rest of the function Joe REM ----- TELL TRS-80, COLOR COMPUTER, PET no RUN or CLEAR function in LISP that will reset all until the final CDR A returns a NIL (until the remainder of A *** ASK *** 316 FOR R=1 TO P-1 FUN 320 Rs= "KNOCK ! KNOCK!" & APPLE II variables to a known value, nor any distinction between sym­ is an empty list). The COND in Listing One is directly equiva­ ( A ) 330 G05UB seo ELEMENTARY MATH bols used for program elem ents and symbols used for data. To lent to line 340 of Listing Two. "If there is no response to the ( PRINTLIST A ) 340 IF 1$="" THEN R=P: Gom J90 ( PRINT) 350 R$=Js(R,i) SCIENCE BIOLOGY initialize ourlist, we would type "FORGET IT" in LISP, and prompt 'KNOCK! KNOCK!', stop." In LISP, the CAR of a list <" SET(,) INPUT J60 GOSUB 580 (RERD» GEOGRAPHY HISTORY "RUN" in BASIC. is it's first element; the CDR is the rest of the list. Take a look 370 PRINT Js(R,2) ECONOMICS ACCOUNTING at JOKES in Listing One. On a first pass, (CAAR A) is INPUT) JSG PRINT Next, let's look at the function ASK in Listing One (lines J90 NEXT R FOREIGN LANG. BUSINESS ED. 500-540 in Listing Two). The symbol INPUT in Listing One is "ELIZA". (CDAR A) is "ELIZA DEAD ... ". (CDRA) is the 490 STOP GRAMMAR FARM RECORDS a variable, not a function. ASK means roughly, "print out the rest of the list, from "JOSE ... '" on. (SETQ A (CDR A» is Sample run of LISP program 500 REI'I ----- RSK COIN INVENTORY value of A and read the operator's response. Set the symbol equivalent to the "NEXT A" in BASIC. Notice that we are 518 PRINT AI TINY LISP RERD'r' 528 If="" INPUT equal to this response, and return it to the calling changing the value of A, not of JOKES, just as in BASIC we 530 INPUT 1$ Write for FREE Catalogue: function." A$ and 1$ in Listing Two correspond directly to A are changing the value of the loop-counter A, not the top-of­ JOKES 540 RETURN MICRO LEARNINGWARE, Box 2134, N Mankato, MN 56001 and INPUT in Listing One. Line 520 clears 1$ so that the list pointer P. JOKES There are many threaded languages that use named varia­ (507) 625-2205 BASIC can detect "no input." The SETQ is necessary in TINY LISP RERDY VISA & MASTER CARD ACCEPTEO Listing One because the READ function returns the value bles and procedures, but LISP offers an unusual degree of FORGET IT *KNOCK KNOCK! entered without assigning it to any symbol. freedom from type declarations and resource allocation tasks. We pay 15% royalty for Educational JOK£S Who's there? Programs listed with us. Let's get back to our joke list. The function KNOCK in It is almost never necessary for the LISP programmer to know TRS-80 is a registered trademark of Listing One and lines 200-290 of Listing Two are used to add where a structure is stored or how much storage it's using. Pro­ TINY LISP READY Venice gram elements are lists exactly like data lists, and can be TANDY CORP. new jokes to the joke list. The COND function is the LISP KNOCK KNOCK Venice who? PET is a trademark of COMMO­ form of IF. KNOCK translates, "If there is an answer to the manipulated with the same primitives. If you're not turned WHO/S THERE? Venice you going to open dis door? DORE BUS. MACHINES. off by the complex grammar (LISP = Lots of Infernal Stupid BOO question 'who's there?' then SETQ JOKES, etc., else stop." BOO UHO? APPLE is a trademark of APPLE Parentheses), LISP offers a real alternative to the procedural BOO HOD HOD! ... from Knock Knocks, Tile Most Ever, by COMPUTER CO. David J. Beard, RD#l, Box 648, Newmanstown, PA 17073. languages with their cartesian arrays of data. • JOKES William Cole. Dell, 1976. 30 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September-October 1981, Issue 53 31 IGames and Programs by Joey Robichauxl

used in photography for lens design and table generation. to admit a small portion of light for a long (relative) period of customize this program by changing three DATA statements While lens design is beyond the means and interests of most time. In either case, the same total quantity of light is admit­ near the end of the program: the table of f/stops, the table of For amateurs, table generation is applicable to an amateur and is ted. For instance, a camera setting of f/8 with 1/60 second lenses and the table of focusing distances. Note that lens sizes easily performed on any personal computer. may produce a proper exposure, as would several other combi­ are stated in millimeters, and focusing distances are in feet (I In any photographic handbook you will find many general nations of f/stop and shutter speed. Since there can be many try, but I still don't think metric); the program will perfonn purpose photographic tables. Probably the most imp0r:tant different settings that produce a proper exposure, how do you the necessary conversions. Those of you desiring output on a Photographers tables for a beginning photographer are the depth of fIeld determine which is best? screen may wish to change the PRINT statements, also. • tables. Depth of field is a fundamental concept of photo­ This is where depth of field comes in. Generally speaking, graphy. Happily, depth of field tables can easily be generated the higher the f/stop setting, the wider the depth of field. Only! by any home microcomputer. Before we look at how to gene­ Depth of field is dictated by the f/stop; since f/stop is affected rate customized depth of field tables, let's examine what depth by shutter speed, we can say that shutter speed indirectly 11) PRH i: of field is and why it is so important to photographers. affects depth of field. 20 ?!IIS'l Depth of field is the range of acceptable focus in front of Most beginning photographers will choose a shutter speed ) 0 ~p.~ •••••••••••••••••••••••••••••••••••••••••••••••••••••••• and behind the subject that the camera is focused on. If your and then vary the f/stop to reach a correct exposure. By doing 41) REI': BA S Il.: ? IHlGIlAI! TO DETf.9.IIISE N~AR DI::PTI! OF fInD • subject is 15 feet away, your depth of field may be from 10 to ~ o R ~I! A~D fA ' DlPTH OF fllLD Dr-PENDING ON F/STOP, this, they lose direct control over depth of field. They should 6 0 ~ !'! I! f 0C U S I ~:<> DI STAH CE, AND f OCAL LENGTH Of L!IIS IJ S ED. 25 feet. Even though your camera is focused on IS feet, ob­ instead select an f/stop that will give them a desired depth of 7 0 RE" II RIT':' E'> : 5/1/19 JOEY BOSICIIAUK 80 11 3 :1 ¥ AR IA6L ! S : !'l~f/S'l'O PS, f2"fOCAL LENGTI:I5 (n£Tl'ICj jects between 10 feet away and 25 feet away will also be in field, and then vary the shutter speed to provide a proper ex­ 'l0 1'U " f ) =t' OCAL LfNGTI!S ISl'AMtARD). 01"FOCUSI!I'G DI S TANCE focus. posure. 1 00 "<': :01' ri2 " ~IIP fRf OC AL DISTlNCE, 19=IN~I!i1TY 110 p.~, •••••••••••••••••••••••••••••••••••••••••••••••••••••••• Let's look at another case. Suppose you focus your Since most photographers want the widest depth of field camera on a person's face 2 feet away from you. Your depth 121 !( ~, possible, this policy is fairly easy to apply. When taking pic­ 130 on ~ 1 (13).1'2 (" ) ,f) (5 ),Dl (1 0 ) of field may be such that objects from I foot 11 inches to 2 nues, always use high f/stops combined with slow shutter 1110 IIEI'I feet I inch away are in focus. Your subject's eyes will then 150 RE"! OBTU'/ 'rtll': APERT UR ES If/SlO PS) A~fI STORI'! IM r1 speeds. This does not mean you are doomed to fuzzy pictures 160 f OI'! 11 " 1 TO 1) appear crystal clear, but his nose and ears will be out of focus. caused by slow shutter speeds; 1/60 second is slow and it is 170 RHO fl (I1) It would be wise to chuck this particular photograph in the 1110 MEKT 11 adequate for most situations. 1/125 second is still fairly slow 1':10 REI! trashcan. yet it will freeze the spokes of a racing bicycle. 200 RE" OBTAIN TEfP. f OCAL L!NGTI!S(lN '0")) A good understanding of depth of field is essential to 210 R:el! AIID CONV£R'1' TO INCII!S (III f2) Let's imagine a scene where depth of field is used to corn­ 220 FOP. 11 .. 1 TO 5 produce effective photographs. Creative use of depth of field pose a picture. You are at a white sandy beach dotted with 2)0 !lEAD f) (II) can give your photographs a professional touch. How then, can 2!W LET f2 (11) .. f3 (I1)/25.1l several hilly dunes; warm waters are lapping gently at the 250 HI::IT 11 you use depth of field to your advantage? shoreline. Fifteen feet away you see a pretty girl. These look 260 R E:'I For any particular lens, depth of field is a function of two like the ingredients for an attractive photograph, so enter 270 REI! OeTAIN Th E fOCDSING DISTANCI::S AHO STORE IN D1 variables, focus distance and f/stop. Shutter speed must also Super-Photographer to the rescue! Grabbing your camera, you 280 fOR 11 .. 1 TO 10 290 f< EAO D1 Ill) be conSidered, as it directly affects the f/stop setting. When a focus quickly on the girl, she flashes a bright smile and you're )00 Nf-IT 11 camera is focused on a subject, focus distance is the distance 310 REI! ready to shoot. Just then you notice an unsightly pile of sea­ 320 B!!! PERfO HII f Or. THE NOI'IBER Of DIfFERENT LENSP.S between the camera and the subject. Unless either the camera weed about fifty feet away. From your vantage point, it will ))0 1" 0 11 11 .. 1 TO 5 or the subject is moving, this focus distance is constant when )]5 REI! intrude into your picture. Without repositioning yourself or )40 REII fOR £lC I! DIfFERE/lT LlHS, the photograph is being taken. Once the focus distance is de­ your model, you can use depth of field to salvage this shot. ]50 REI! LET INflNITY .. fOCAL LENGTH (IN 1111) TIllES 10 fEf'1' termined, depth of field is directly defined by the f/stop Simply set your camera to obtain a narrow depth of field )60 LET 19 ,. f)(ll) • 10 )70 PRINT "fOC AL LGT II ","f/STOP","OIST"."lII"AR OOf'"."fAR oo r" setting and indirectly defined by the shutter speed. Since shut­ by using a high shutter speed and a low f/stop. Focus on the )80 fOR I2 " 1 TO 13 ter speed and f/stop can be varied, depth of field can be varied. )90 RlII girl 15 feet away; your depth of field may now be such that 1100 B!I! FIND IIYl>ER'OCAL OIST11lCE (112) You may selectively alter the f/stop to create a desired depth everything from 12 to 20 feet away will be in focus. Now the 1110 Lin' 112 I" 2 (11).1'2(11)/F1(I2)'1000/12 of field. Let's look more at shutter speed and f/stop and see ~20 !'OR 13 " 1 TO 10 objectional seaweed lump is just a fonnless blur against a soft, ~)O REI! how they affect depth of field. fuzzy background, providing you with an effective picture. Shutter speed is a fairly simple concept; it is the amount 1l1l0 REI! FHO II"AII DEPTH Of fIELD (021 lIlD fA£! D.O. f. (D)) Depth of field can be effective in reverse, also. What if, in­ 450 LET D2 '" 112'01 (Il)/(H2+01 (Il) -f2 (.11)/12) +.0111667 of time that the shutter is open when a picture is snapped. A stead of a messy seaweed pile, there were a majestic horse and 460 LET 0) .. H2'01(l3}/(H2-01{IJI-f2(I1)/12)+.041667 A Depth of Field shutter speed of 1/60 second indicates the shutter will be open rider emerging from behind a sand dune fifty feet away. Now 1170 REI! 4BO REI! COH1EIlT D2 AND D) TO fEET AND INCIU':S for 1/60 second. the camera can be set to obtain a wide depth of field by using 490 lin USIHG IIIrEGER AIIITHI!ETIC F/stop, on the other hand, gives a lot of people trouble. a high f/stop and a slow shutter speed. With a depth of field 500 LET IS .. INT(02) Generator 510 LET 16 ,. IIIT(03) Actually, f/stop isjust as basic and simple as shutter speed.. from 8 feet to infinity, you can snap your model with a 520 LET I1 .. INTI (['2-15) "2) Think for a moment about what happens when you snap a PiC­ 5)0 LET 18 " IHT{ (0 )-16)' 12) rom a hobbyist's viewpoint, there are two ways to consid­ sharply focused horse and rider in the background. 5110 R '!I! er a home computer. On one side, the micro can itself be ture. The shutter will open and allow light to pass through an Since depth of field is such an important part of photo­ 550 ifl! If L"S5 TIIAH ZEICO OR <>T 10 TIllES FOCAL LEIIGTH. 560 REI! !'lAKE IT EQUAL TO INl"INITY (999'99") Fconsidered a hobby; downing Klingons, solving Adven­ opening to expose an image on a section of film. This opening, graphy, all lenses have a depth of field scale painted on their tures program writing and glitch tracing are all enjoyable and known as an aperture, can be of variable size. F/stop simply tops. While this scale is often useful in applying your know­ 570 If 16 > 0 TIlEN 590 profitable ways to spend one's hobby time. Hardware enthu­ refers to the size of this opening. A large aperture will admit a 580 GOTO 600 ledge of depth of fie ld, it doesn't provide you with the neces­ 590 IF 16 ( 19 'I'HlH 1il0 siasts with solder gun in hand also find relaxation (if yOll can greater quantity of light than a small aperture. The tricky part sary detail to understand depth of field. (For example, a slide 600 LET 16 .. 999 call it that) by tinkering and improving on home computer about f/stops is that f/stops are stated in inverse relation to the rule is useful in applying multiplication, but it doesn't help bl0 L!!:T Ie ,. 99 size of the aperture. For example, a high f/stop such as f/22 systems. you understand multiplication.) It is for this reason that 620 P~I ~ T r 3{I1),f1 (12),01(13),15;*' ";17;~".,16;"' ";[B;"". On the other hand, a home computer can be used as a tool indicates a small aperture; a low f/stop such as f/2 or f/1.7 photographic handbooks contain depth of field tables. These 6)0 NP,XT 11 6~0 HUT 12 for the enjoyment of a separate and different hobby. While indicates a large aperture. tables can be studied and are a valuable tool in understanding 650 PIUNT it is difficult to picture someone chuclding happily to himself Now that we've introduced f/stops and shutter speeds, 660 NI::KT 11 the depth of field capabilities of different lenses. &70 RUI while he designs a new general ledger system, there are many let's see how they can be used to obtain depth of field. To do The following BASIC program will allow you to generate 680 REI! tABLE OF f/STOPS fruitful applications whose enjoyment can be enhanced by this, we must understand what constitutes a proper exposure. your own depth of field tables. Of course, you may alter the 690 DUA 1.4,1.7.2.0,2.8,3.5,4_0,5.6,6.3.8.0.11.0. 16.0,22.0, )2.0 a microcomputer. For example, hobbyists in fields such as In any situation, a certain total amount of light ,must be trans­ parameters to personalize the tables for your own lenses; per­ 700 R Ell astronomy and model airplanes (as in aerodynamics) find per­ mitted to enable a proper exposure. This quantity of light may haps you may wish to examine the properties of a lens you 710 REP! TADL! or LUStS (IN 1111) 720 DATA 28, )5, 50, eo, 135 sonal computers a valuable tool in the pursuit of their hobbies. be obtained by combining a large aperture with a fast shutter wish to purchase. This program can be easily modified to run 730 REI! One field where a hobbyist can use a home computer is speed to admit a large portion of light for a short time. Con­ on any BASIC-equipped microcomputer. The equations used 740 REI1 TABLE or fOCUSING (OR SUBJECT) DISTANCES 750 DAN 2, 5. 8, 10, 13, 15. 20. 25, 40, 70 amateur photography. Commercial computers have long been versely, a small aperture may be used with a slow shutter speed are found in any good photographic handbook. The user may 760 e:fO 32 Recreational Computing. September·October 1981, Issue 53 Recreational Computing, September-October 1981, Issue 53 33 IGames and Programs by Mary Ann Gohlkel

beat the program one or two times but almost no one can beat Ok, Lisa, since this is the first game, n~ACCI NIM ~ .. I'll choose the pile size and you choose who starts. ",ritt!en by I-lary }\nn Gohl ke the program all three times. in the Sprin University of liouston Victoria CampJs €I Fibonacci Nim Original program, for computer-k level TRS- 81.:, a 16 II MBASIC (c) but is easily modified to TRS-80 Level Two I choose a pile size of 30 . sutmilted to !li:CREA1'IONAL CCJ.1fVJ'IM;. BASIC; the apostrophes act like REM's and the colons sepa­ Do you want to start? yes 3 CLEflJ< src rate multiple commands. All of the displays are designed for 4 GOSUB 2C(lC modifications made by Furman Slnith at UHVC for the Zenith/He<>th Al l-in-che 16 lines and 64 columns (such as found on the Model I and It's your turn, Lisa, you have 30 green cars 5 GOSUIl 90:':C RULES and you may take up to 29 green cars. 6 " III TRS-80's); the initial display uses an antimated dash (pro­ ------INITIALIZATION ------duced by line 2160) to allow viewer time to glance at the How many green cars do you want to take? 1(; f9=20 ' see end of the program for a Jist of variables 11 DIM f(F'9) credits before seeing a sixteen-line frame of rules. 9 15 Bl=O The 3000-3999 block explains H89-related material. The 2() 82=1 25 roo. 1=1 'I'O f9 "PRINT CS$" (defined in line 2010) clears the screen; the Hmm, that was an interesting move, Lisa. 30 f(I) = 81+132 screen never really needs clearing so you can delete or substi­ Let's see, there are 21 green cars and I can 35 Bl=82 40 U2=f(I) tute as you like. The FCNL$() can be deleted if all input is in take up to 18 green cars. 45 NEX1' I capital letters; it maps lower-case input into upper case. Line This is going to be tough! 511 INfVJ' "Are you ready to play" ;AS 53 If 1\$="" THEN A$ ="Y" 2030 perfonns the function that many BASIC's handle by I'm going to pick up just 1 this time. 55 A$=FNL$ (A$): If A$= ~ Y " GOl'O 90 "RANDOM" - seeding the random number generator. H89 That'll leave you with 20 green cars, 6lJ INPUT "Does anylxxly want to pl ay" ;A$ 65 M=fNL$ (1\$) : If A$="Y" caro 90 MBASIC uses RND(I) where the TRS-80's would use and the possibility of picking up at most 2 green cars. 70 PRIN'r "Sorry no one wants t o play," RND(O). 75 PRItII' "It's really <> fun game ." BO PHINT "M.,.1ybe some other time . Bye now!~ I guess that Michael J. Whinihan, who described the opti­ Who's next? Johnny 85 SIDP mal strategy in the December 1963 issue of The Fibonacci 88 ' 9{: INPUT "How ITnds, toys •• Here we go! 145 INPUT ',,",j,at kind of objects do you want in your pile";OS(H) and a pile of objects. The players take turns removing objects at least one object must be taken on each play. 14(. PRINT "Jf you want ";O${H);", ";N$(H);", you can have them!" I choose a pile size of 41 . from the pile and the person who removes the last object wins A player may not take more than twice the number 148 PlUNT :PRINT Do you want to start? nope 149 ' the game. Each player must take at least one of the objects on of objects that his or her opponent took on the last play. IS" CN SIB) caro 2r'.O,3C!),t.nO,5VIl each turn but cannot take more than twice the number of ob­ For example, 151 ' Nice of you to let me start, Johnny. 199 ' f' jectsjust taken by the opponent; for example, if one player if one player picks up three objects, ------fiRSf GN-IE ------Let's see, there are 41 French fries and I can 2[){~ PlUNT "Ok, ";N$(H);", since this is the first game," takes five objects, then the next player cannot take more than the next player may not take more than six objects. take up to 40 French fries. 2C5 PRItII' "I'll choose the pile size and you choose wno stilrts." ten. The first player cannot take the whole pile but can take The player who takes the last object wins! 2CG 52=I N'I'(1+1C*RND(l») : If' 1:12>6 TIIEN FlOl)=1 €' any smaller (positive integer) number of objects. Let me think about this ... PRINT "I'll even go eilSY on you this first game."

The program allows the computer to play against many I'm going to pick up 2 French fries. 21e PRINT ~Here we go!" people simultaneously. Each person gets to name the type of That'll leave you with 39 French fries, 215 GOSUB 600 220 Garo HlOO objects (pizzas, diamonds, French fries, etc.) and the computer and the possibility of picking up at most 4 French fries. 299 '(I remembers the type of object associated with each person. ------SOCWO GN-IE We will play three games. For the first game, 3!l0 IF W(HJ>O GO'I'O 355 People need not play in turn; when a person has decided on I'll choose the pile size and you choose 3Ul PRINT her or his move, the person tells the computer and the com­ Who's next? Lisa 3!l5 PRitII' "Since I -..un the last game," who goes fust or second. Thereafter, the wmner 310 PUNT "I'll choose the pile size and you choose who starts.~ puter reviews the game situation and accepts the move (if the chooses the pile size and the loser chooses 311 B2=IN'I'(l+1C*RND(I)) : IF B2>5 THEN Fl(H)=l €I move is acceptable). Each person is played three games. The As I remember, Lisa, we are in : PRINT "I'm going to give you a chance to win -- BE CAREfUL 1" who starts. 312 If B2>5 caro 340 game 1 and it's your turn program allows a few more players than it was initially told of, Just to make it more fun, 315 PRIl'lI' "Unless you want to choose the pile size _ " with 20 green cars to work with. 320 PRINT "guess we could bend the rules u little." and as players finish their round of three games, storage space I guaran tee that 325 PRINT "Course, then I'd get to choose ...no starts." for new players is made available. Is that correct? Yes 330 INPUT "Do you want to choose the pile size";A$ I won't lose all three games. 335 A$=FNL$ (A$) : If A$="Y" GOTO 397 Suppose the program i~ to be demonstrated all day in a 340 GOSUB 600 : GaI'O leOO It's your turn, Lisa, you have 20 green cars shopping mall. We would anticipate that some players will Are you ready to play? yes 344 ' and you may take up to 2 green cars. 355 INPUT MAr e you'ready for g<>me two";A$ wander off without finishing their three games. The demon­ 36!l A$=FNL$(A$) :If !\S = ~Y" GOTO 387 How many green cars do you want to take? strator can type "LIST NAMES" in response to "Who's next?" How many people might want to play? 2 365 INPUT "!\ren't you goirl9 to give me a chance to winN;AS 2 370 AS"fNLS (A$) and get a list of the players - this is useful if someone has 375 IF A$="Y" mEN PRltII' "Thanks ";N$(H);~1 Here we go! ":GOTC 390 forgotten how his name was entered. The program then 380 PRINT "Aw, come on ";N$(H);", since we <>greed to 3 g1'lmes," Ready to start? yup That was a good play, Lisa! 385 PRIl'lI' Mit is only fair to continue." asks if any of the names should be deleted; the names of 387 PRINT " Here we go with game two !" missing players can be removed to make room for new players. Now, it's my turn. Let's see, since you 390 PRIl'lI' "Let's see, since you won the last game," took 2 green cars, I can't take more 395 PRINT "you get to choose the pile size and I pick who starts." If a new player has the same name as an old player, the pro­ 397 GOSIJB 655 : GOTO !cWO gram asks for an additional name to distinguish the two The pile of objects we are playing with than 4 green cars. 399 ' €I can be a pile of anything. I'm going to pick up just 1 this time. ------TIilRO GAME ------players. 400 If W(H) > 10 GOTO 420 In the first game, the program selects the pile size and the For example, sticks, books, apples, diamonds, toys. , That'll leave you with 17 green cars, 405 Fl{H)=1 What kind of objects do you want in your pile? green cars and the possibility of picking up at most 2 green cars. 4111 PRINT "Don't give up "; N$(H);"." human chooses who goes first; thereafter, the winner selects 415 PRINT "I'll go easy on you this t ime." the pile size and the loser picks who starts. The program is 42>'1 PRINT "Here we go with game three!" satisfied with one win out of the three games; most people can If you want green cars, Lisa, you can have them! Who's next? Connie 425 U' W(H»"I~ Garo 39C ELSE GOTO 305 • 499 'f\ 34 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September· October 1981, Issue 53 35 -i~------:r-r ------u~

I IGames and Programs

i 135C PRINT "Since you are not sure, let's go ahead· ------M.L. 'IllRE£ GAMES ARE OVER ------1001 IF T(H) .. fl ooro HI80 9075 PRINT "We will play three games. 1355 PRINT "and pby the game as Is. ft : GOTO 1005 for the first game," 500 PRINT ''Well, ";N$(H);~, ttutt' s 1111 three qllroeS -- ~ 1005 PRINT "It ' s your turn, ";N$(H);", you have ";G(H);" ",O$(H) 9080 PRINT "I ' ll choose the pile sIze 1360 PR I I'n' "Either I'm mistaken or you're pulling" "nd you choose" game, set, and matchl" 1010 PRIm' "and you Ny t.!Ike up to ";O(H);" ",O$(H);"." 9085 PRINT ·who goes first or second . 'nlereafter, the winner" I 501 PRINT: PRINT 1015 PRINT "How many ";O$(H);" do you....ant to t.!Ike?" 1365 PRINT " ' my leg'. Tell you Iohat, let ' s go ahead· 9090 PRINT "chooses the pl.le size and the loser chooses 505 IF ,",'(H)'" () 'Illfl'l G06U6 BOn 1016 INPUT P;PRINT 131\1 PR INt' "lind play this gl!/lle - looks interesting _. 9095 PRINT "wtlo starts." 9IIlne 510 IF W(H)"' 1 THEl'I GOSUB 810 1020 U' P <_ O(H) AND P >- 1 GOTO 1040 1315 PRINT "Here ' s \ohere the is now." : ooro 1005 91e0 PRINT "Just to make it more f lAl ," 1379 ' (I 515 IF W(H)'" 10 THD.! G06UB 820 1025 PRINT ·Now, COllIe on ";NS(H);·, you know you can" 9102 PRINT "I guarantee that" - ---- NDI PLAYER WI'nI OlD NNot£ __ 520 If W(H)- 11 WEll GOSUB 830 1030 PRINT "only t.!Ike between 1 and ·;O(H);· ·,O$(H)"." 9105 PRINT "I won't lose all three games." 525 IF W(H)=H10 THEN ())5UB 85(l 1035 INPUT "tow IIIlIny do you choose";P :PRINT ;GOTO 1020 138e PRINT "Welcoroo to the game , ·;NS(H);· ! Please do· 9110 PRINT : RE'l\JRN 530 IF w(H)=Ull THEN GOOUB 865 104fl GCSUB 8000:G(H)ooG(H)-P 1385 PRItn' · me the fa\IQr of retyping your name and· 9115 I 1390 PRINT " include the first letter of your last name" 535 IF W(H)"lHl 'IllEN GOSUB 880 1045 IF G(H)<-" GOTO 143e 9118 reference: 1395 PRltfT "so I can tell you apart from the " Martin Gardner's MA'IlIfW,TICAL CIRCUS @ 540 If W(H)"lll THEN GOSUB 905 Ilil50 Q(H)-2. P 0979 ; Alfred A Knopf; ISBN 0- 394-5021l7 - 8) 544 • 1051 B2-INT(1 +10*RNO(1)) 1490 PR I NT "other " ; NS(H)," as I can't see. Thanks, " 9120 ' f 545 As .. rnL$(A$) :PRINT : IF AS .. "Y" caro 593 1052 I F 82>5 GOTO 1055 1401 INPUT AS ------LIST Of" VARIABLES ______1405 Gal'O 1195 546 PRINT "Martin ~rdner discusses this game in the chapter on" 1053 If O( H)CH) 9141l FO FI B(W>,CCI TABLE IP56 B2=INT(I+10· RND(1)) 9145 H9 • OF PlAYERS (DIM TABLES) 555 PRINT "Hope we can play "9l1in sometime." 1415 PRINT "I ' ll t.!Ike ";P;" ";O$(HJ:" to finish off the pile" 560 N$(Uj="." : S(H)-} W(H )-0 : Fl(H)"O 1051 IF 82>5 GOTO 1e85 9150 19 I OF PLAYERS AT ANi GlE TIME 1060 PRINT "Now it ' s lIlY turn. Let's since you" 1420 PRINT · and win the game'" 565 fUl 1"-1 TO fl9 see, 9155 F'7 flJlGS If CCJ1P11l'£R lEi' ITSEL.F START 1065 PRINT ";P; " ";OS(H);", I can't take IIIOre" 1421 Fl(HI-0 57C IF 1'1$(1)<>"*" 1165 "took 9160 P f Of CBJECTS TAK~ IN THE PLAY ooro 1070 PRltIl' "than ·:O(H);· ";O$(H);" . · 1425 S(H)OOS(H)+I : ooro 150 575 NEXT 1 9165 H .. SUBSCRIPI' a- PLAYER AT fJ#'( (I.IE TIf'lE 1075 GOTO 1100 1429 'tt 576 PRINT ------l:lJM.&.N WINS ------_ 9170 C I OF CBJfX:'I'S IN ::JHE (USED TO fIGURE 0l1I' CQo\PUT£R ' S PLAY) 11179 " 9175 81,82,I,AS "'> JUNK VARIABLES I sao INPUT "J\nyOOdy else wllnt to play";A$ 1430 PRINT "CCN:>RAruu,TIGIS, ";NS (H);"' 'tOO WIN ! '" 11180 PRINT "Nice of you to let me star t, ·;N$(H); •• 9181l fOR E:ACH PLAYER : I 585 A$",'NL$(AS) : IF AS-"Y" GO'TO 14" 1435 If S(H)-l THEN W(HI"""Ctl)+l 1085 PRI tIl' ·Let ' s see, there a r e ·;GCH)," " ; OS(H);" and c"n" 9185 1'0$ () .. IUM.I\N' S twlE ~6 PRINT mINT "Hope you h&d a good time!" 1440 IF S(H)-2 'nIEN W(H)ooW(Hj+10 1090 PRINT "t.!Ike up to ";Q(H)," ",O$(H);"." . '~ 'f' .:;. 0 WI'E. Of ObJECT 590 PfUNT "It ' s been fun! Bye!":STOP 1445 IF S(H)-3 'I'H~ W(H)ooW(Hj+HlD 1091 B2"INT(1+10*RNO(1) :; ;'~5 :.' , f.' '··I" ~;., il~.;) GAME FOO. a:;to!PVTER 591 ' 1092 IF G (Hj 5 ooro 1095 1450 S(H)toS(tI)+l 593 mrt>lf "Fantastic! Here we 90 again!" 1451 F1 (H)al) 920e S() GAME I t 1093 IF Q(H)I PRINT ~'This is going to be tough!" GOTO ll00 , 595 S(B)"1 W(H) -" : Fl(H)-O : GO'TO 15" 1455 If S(M»-4 ooro 150 92115 WO HUWIN ' S I CE WINS 596 ' 1094 PRINT "/bw, this is interesting , · ; ooro 1100 9210 TO WHO STARTED: 1) .. >CQ.1PUTf1l., l ->Hl»\,It,N 1095 PRINT ·Let me think about this " 1460 PRINT ·Hope you are ready for the next garoe, ";NS(H.j;·.* 599 ' !'I 1465 PRINT "You're not going to Qf!lIt me this time ' " 9220 00 I OF C8JEC'I'S I..£GAL 'I'O TAKE I 1097 FOR J=l 'IO 1000 :NEXT J 9225 G () I Of' C6JEX:TS IN GllME ------CCJ1FVl"ER OIOOSES PILE SIZE ------1470 GOTO ISO lC99 ' @ 923e ! 6eO B2"'INT(l+50·RNDO) ) UOI) '@ (,()2 If 82<20 ooro 600 ------a:MPI.TI'm ' S 'I\JRN ------additions for the Zenith/Heath All-in-<.ne version _ 9231 CS$ clears the screen on the Zenith/Heath All-in-<.ne computer . IHlCl f"OR 1"1 TO 50 ;NEXT I ; If O(H»O(;(H) G01'O 1410 92]3 £Nl.S (AS) returns the upperc"se of the left/R:lst character of AS. 60S f"OO I~l TO f9 2001 ' made by Furman Snith "t the Un!. of Houston Victoria Campus 610 IF B2=f(I) GarO 625 1105 C=G (H) 2010 CS$ .. CHR$(27) + "E· 9234 flIrl, flIT2, FNT3 are used in the COOlP'ltation of I'NLS. 111'1 f"OR I-I TO F9 9235 ------£NO Of f'RCGflN'l - ______615 H' 82«(1) 001"0 630 2B20 PRltn' CS$ , clears the screen 1115 IF t'(I) .. C 1130 I 620 NEXT I ooro 2031l I - RND( -PEEK(8219) ) , seeds the tIX)S random I"Ulber generator 1120 I f F(I)>C THEN 1-1-1 : CooC-f(I) GOTO 1110 625 B2"B2+1 2040 DEF flITl(X) .. - X • ( X <_ 95 ) '@ 1125 NEXT I 53C C{H) =B2 : 0(H)-S2-l f"N'l'l(X) is X if X If X i$(l't over 95 and is 0 otherwise I 635 PRINT "r choose a pile size of ";G{H);"." 1129 2050 DE:F flIT2(X) - - ( X- 32 ) • ( X> 95 ) 640 INPUT "00 you want to st.!lrt";A$ 1130 peFCI) 645 1I$=1'NL$(A$) : U' AS-"Y" THEN T(H)=l ELSE TCH)-C 1135 IF PO(H) THEN POOl 2060 Il::f flIT3(X) - ~"N'l'l(X) • FNT2(X) ' f! 650 RI:.""I\JRN 114\1 If Fl (H) -I nt~ GOSUB 1265 FNT3(X) is either X or X- 32 ! 651 ' p 1145 Q(H)c2.P : G(H)o(;(H)-P 2inD DEf £NL$CAS) = CHR$( FNT3( ASC( LEFTS( A$, 1»))) ' (I educational software for the ATARr educational software for the APPLE'= ------H1..I'\NII OIOOS£S PILE SIZE ------115(1 IF PH 'nIfl>I PRINT · I'm going to pick up .;p;" ":OS(H);·.~ I'N[.$ (AS) is uppercase of the left/R:lst character of AS • + I G55 INPVT ....'ohat do you choose for the pile size";GCII) 1152 IF P-l TH~ PRINT · I ' m going to pick up just 1 this tiroe.· 2100 PRINT TAB(5);· *.. F19CJ.IACCI Ni M .... , 660 U ' G(H»10 ooro 675 1155 PRINT "'Ihat'U leave you loIith " ;G(H)," ";O$(H)," , · 2110 PRIN'l' TAB(5);-....ritten by I'IlIry Ann Gohlke· i HIDDEN WORDS : 665 PRINT "N.I, 00fI'It' on ";NS(H) ; " , you can think of a" 1160 PRINT "and the p:>ssibility of picking up "t m:)st ";O(H);" ·;O$(H);". " 2120 PRII'n' TAB(5);"in the Spring of 198~ .... Ue she was a· :I Aword·search program for the ATARI·. I 610 PRINT "more chllllenglng game than that - try again'":OOT"O 655 1165 PRItfl' : PRINT 2130 PRINT TA8(5); " senior lit the University of tbuston Victoria Camp.lS" f j 615 O(tl):G(H)-1 1169 ' @ 2135 PRINT TAB(5);" (subnitted to RECREATIO n!EN P-VAL(AS) :G01'O 11121) 1999 ' I CYP CVFNS)( I FJO"IOKF • 1m: T{II)"l : PRUn' "Ok, ";N$(H);", I'll let you 90 first.":Rf.."ruRN ~II r ..... CLV)((VVOySCGtiISOl Four levels of play .~. FOR TO 8000 If' P-INT(P) THO! RE'nJfll>l 7C5 B2-1N'f(1+10·RNO(1) 1175 I-I H9 .. J /'\ JS~FOY N)(UUJOR/I\U I N • Comes with word base of the most 1181l IF NS(I) -AS G01'O 1300 8005 P-INT(P) : PlUNT ·1 101111 take that to mean ";P;@ 7IC IF B2>5 001"0 735 ~ CEGAI R.RIA~~SPTVVN frequently misspelJed words. 715 PRINT ·Tell you what, ";N$(H);", I'll even let you 1185 NEXT I ", as \ole can ' t split the "; O$(H); ~ 12C mINT "pick who starts." 1190 PRINT "Greatl " new player' Welcane ";AS,·!· 8010 R£'ruRN iii ., 116 • Requires JOYSTICKS 725 INPVT "00 you want to start" ;AS 1195 19"19+1 8011 ' 8049 '@ 24K BASIC, Grades ]·8+ S1 7,50 ~ 130 ~ "'fl.Jl.S (AS): If AS-"Y" nt~ T(II)"'l ELSE T(H)-O 1200 If 19 <- H9 ooro 12SQ i 731 RI:."TURN 1201 I9:H9 -- LIST AN!) [E:LETE PLAY~ 735 T(H) =l-T(lI) 1205 FCR 1-1 'I"O H9 8050 PlUNT : PRIN'l' ... NAM~ 0.. PlAY~ .. ~ 14C If" T(H)=O cerro 750 121C If N$(l) ..... THEN H-I : ooro 1255 8055 FOR I-I 'l"O H9 ,g SPATIAL RELATIONS 1215 NE:;){T I 8060 IF NS(I)·"· 001"0 8081) ~ 7~5 mIWI" "Since! started the last time, ";NS(H);·, I'll let you go first."@ Designed to help the child learn words : RETURN 122C PRII'n' "Oops, you didn' t tell me thi s IIIlIny people" 8065 IF N$ (I)-~ . " GO'TO 8015 B For the ATARI· B07(: PRINT • ~ ;N$(I) 799 ' ~ 1225 PRINT "were going to p1"y. Unfortunately, I didn' t· ~ ' that indicate size and placement Units B075 NEXT I ------c:a>'f'lEN'I'S GI RESULTS OF GN'IE ------1230 PRII'n' ".., 11010' for this many players. If you don ' t " • cover. big/small, tall/short, right/left. 1235 PlU NT ·mind , · ;AS;", please wait till SOII"teOne finishes ft 8c80 PRIN'l' : INI'I!l' "Is there any player that should be deleted" ,1\$ THIS 18- 600 PRINT " Sorry, ";N~(H);", that you didn ' t win any games;· high/ low, over/under, in/out Req ui res S05 INPVT "would you like to try again";AS :RETURN 124~ PRINT " playing , then we can play." 8C85 l\$-n .Jl.SCAS) : IF AS="Y" THflII CO'ro 80~ ElSt GO'TO 1110 ± 810 PRINT ·Congratulations, ·;NS(H);" ! you won the first ~me'" 1245 INPUT ...... 'I1o ' s ready to 1III!Ike II move· ;A$ SII90 INP\IT "Who should be deleted· ; AS ~ one joystick. Minimal read ing. SIDE 81G 815 INPVT "would you like to t r y again to win 2 out of 3",AS :RE'l'URN 1246 PRINT"\IS" ~ Y " THflII GOTO B090 ElSE caro 1170 ,£ Type-N'-TaI~' · ··· speech syntheSizer (VOTRAX). ~ 8130 ' 850 PRINT " Let's see, as I recall, you won the third gllJlle," 1261 ' 8999 '@ Let your computer ta lk with one of the easiest to use speech 855 PRINT "and I took the other two . " 1265 P-IN'l'(GCH)/4- 1) ~ i:; ------RULES ------______860 INPln' "Are you Interested in playing another set·;AS ;RETlJRN 1270 If P<1 00 P>O(H) THE}.! [>001 i synthesizers on the market ~ 865 PRINT "If I hadn't won the second game,ft 1275 RE'ItlRN 9UIl0 PRINT 1276 9005 PRINT "WELC.'CtIE 'I"O nIl: GAME Of" flBOOACCI 1'011'1)· 870 PRINT ~you would ' ve taken .!I ll three games - you're good'" 875 INPVT "00 you want to see if you can win all three games·;AS : RETURN 1299 '€I 9CI0 PRINT "'The game beqins with a pUe of objects. Requires RSf.ii: $375.00 9020 PRINT "the play alternates between the two players· 1 E.Sj. S. i 880 PRINT "Goodness, ";N$(H);", I may have won the first game,~ RECAP ------885 PRINT "but you sure had a strong finish , winning the other two," 13110 H.. I 9025 PRINT "and consists of re\fDvinq objects from the pile . " 890 INPln' "Would you like to try again";AS :R£'ruRN 1305 PRINT "As I remenber, ";NS(!!);", we are in· 9030 PRINT "the first player cannot t.!Ike the entire pile and" 1310 PRINT ·game ·,S(H);" "nd it's your turn" 9(135 PRINT "at least one object IIIJSt be t./Iken on each play. 11 P.O. Box 147 • Garden City, MI 48135 ~ ~~~ :~~ ::~\,~: ;~H!i;'l;uam:r:n~ta!u=t: . ~ it, " 1315 PRINT "with ·;G(H);" · ; OS{H) ; " to work with." !)(J40 PRINT "" player may not t.!Ike m:)re thi!tn twice the rurter" or call (313) 595·4722 for C.O.D. go 915 PRINT "I BEX; YOU , RE."ruRN ME 'IO MY au:ATO 'nIEN P-VAL(AS) : PRINT ""'Y, you are in a hurry'·(1 9055 PRINT "if one player picks up three objects , · DEALER INQUIRIES WELCOME ~ 925 PRINT "Despite the hunilhtion (WOO SAID C(M~ HAVE NO FEELIrGS?)," : PRINT: GOTO le20 Please add: $1.50 shipping/handling, $1.50 for C.O.D.. Mieh. res. add 4% sales tlIJI. 930 PRINT "I shall invite you once again to play with me --" 1325 A$>=I'N[.$ (AS) : If AS.·Y· GOTO 1005 90('C PRINT "the f'\Cxt player lIIo!Iy not t/lke more than six objects.· AI.~ 9065 PRINT "the player who takes the last object wins," 935 INPVT "would you like to";AS :RE."iURN 1330 INPUT "Are you II new player·;1\$ " WRITE FOR FREE CALAlCXi '" 907U mINT ""'hen ready for more information, press the 'EN'l'ER ' button." 0( 999 ' @ 1335 I\$«FNLS (-'$) : IF I\$-"Y" ooro 1380 ~ • Ar ARt is tflldemerk of AtlIr~ Inc. "APPLE Is tflldemerk Apple Computer. Inc. " "r)'Pl!" ·N· Talk;5 91171 INPUT 11$ trlldemerk 0( VotfllX. 0' 1340 INPUT · Are you sUreft;1\$ .s ------HUJoVIN ' S 'IURN ------9072 !'HJN'I' CSS HI00 IF <7=1 THEN <7-0 : GOTO 1085 1345 A$=I'NL$ (AS) ; IF AS-· Y· GOTO ))60 oue"'llOS leuo lle:)np~ u+1I 31ddV ~ Ifl JOj aJeMljOS leu o ll e;)np~ JHVIV ~ 4 1 '" 36 Recreational Computing, September· October 1981, Issue 53 Recreational Computing, September· October 198 1, Issue 53 37 ..

IGames and Programs by Ralph Robertsl

BASIC 0380 RETURN 0390 LET F$" MI D$(B$,X+l,l) #RUN 0400 IF F$ ~ "C- LET T-T+90 , X-X+l , COTO 290 0410 IF F$--L" LET T=T+40 : X"'X+l,GOTO 290 Roman Numeral 0420 RETURN ROMAN NUMERAL CONVERSION PROGRAM 0430 LET F$"'M I DS(B$,X+l , l) 04 40 IF F$-"X" LET T"'T+9 : X-X+l:GorO 290 Convert FROM or TO Roman Numerals (1 or 2)? 1 0450 If F$ z "V" LET T"'T+4 : X-x+l:GorO 290 0460 RETURN If a bar is over any of the number enter ' 1" a '0' if not? 0 0470 REM ,,: ' vincul um ' subroutine ::: The Computing Teacher is a journal Conversum 0480 INP lTI' ~Enter ONLY t he letters UNDER the ' vincul um '" ,A$ :B$"'A$ :GorO What Roman Numeral do you wish converted? XVIII 170 for educators interested in teaching 0 490 LET AlzO : T "T*lOOO : LET A2ml XV lll = 18 0510 INPUT " Enter t he r es t of the letters (those not under the bar)", using computers and teaching about B$ : GorO 170 Programum Want another (1= 'yes')? 0520 REM ::: Main Ro ut ine for Converting ARAB I C t o ROMAN::: computers. It is aimed mainly at the 0550 INPlTI' "What is the Arabic Number to be converted t o RCfoIAN" ,B$ 0555 LET A"' LEN (BS) : DI M V$( A ) precollege level, elementary and ROMAN NUMERAL CONVERSION PROGRAM 0560 FOR X-A T O 1 ST EP - 1 0570 LET C$ zMI D$(B$ , X, l) secondary school. Each issue carries in asic-Bay for your Convert FROM or TO Roman Numerals (1 or 2)? 1 0580 I F C$"' "O" Goro 730 0590 I F X2 THEN 9 0 major topics. Keeps track of student Roman civilization under. • 0 120 PRINT : P RINT:I F 1- 2 coro 520 progress. A new HI-RES version is available. 0 1 30 REM: .. ma i n r ou t i ne fo r conve rti ng fROM The Computing Teacher 0 140 INPlTI' "If a ba r is over a ny of t he numbe r enter '1', a '0' if PH YSICS - P"'IIrams for the high school I % Computing Center not", Al student. 0150 IF AI-I Goro 470 I Eastern Oregon State College 0 160 INPl1l' "Wha t Roman Numeral d o you wis h converted",B$ THE APPLE GRADE BOOK- The 0170 LET A"'LEN ( B$) : FOR x-I TO A: LET C$-MI D$( B$ ,X,l ) I La Grande, Oregon 97850 0190 I F C$ ~"M " LET T"'T+I000 : Coro 290 complete grade book for all teachers. 0200 IF C$-"O" LET T-T+500 I 02 10 IF C$ - " C" GOSUB 350 I 0220 I F C$ - "C" LET T a'J' +lOO All Available for the APPLE II I I 0230 IF C$- -L" LET T aT+50 Name 0 240 I f C$" "X" GOSU B 390 I 0250 IF C$"" X" LET T -T+I0 FOR INFORMATION WRITE I 026 0 I F C$"' " C COSUB 4 30 I Addres$ 0 270 I F C$"'"V" LET T-T+5 aSSOFTWARE I 0 28 0 IF C$"'-I" LET T- T+1 140 Reid Ave. I City I 0 290 NEXT X Port Washington, 0 3 00 IF Al z 1 Goro 490 I I 0310 PRINT , PRINT:If 0'1 2-1 P R INT"(":A $ :~ ) " ; N.Y. 11050 State Zip 0 330 PHIm' B$;" - ":T: GorO 8 1 0 I I 0350 LET F$-MID$(B$,x+l,l) -CHEMISTRY Is also avaUable for the TRS-&l 0355 REM ,: : 3 subroutines f o r '4' " '9' anomalies .. . 0360 IF F$""M" LET T _T+900:x", x+l:GorO 290 ------0370 IF F$""O" LET T _T+400:X"' X+l:Goro 290 38 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September-October 1981, Issue 53 39 IPocket Corner by James S. Evans, Jr.1

520: R=INT(L *S +I) The section of program after the ran­ The last section of program in my 820: GOSUB 500 530: RETURN dom number generator is the Number pocket computer is the Submarine Game. 830: V=R-IOOO A Game Machine Guessing Game. Line 706 allows the play­ Here the obj ect of the game is to destroy 831: L=360 It appears to give a satisfactory set of er to decide if he wants to guess numbers the hidden submarine with the minimum 832: GOSUB 500 "random" integers. between one and one hundred or between number of bombs. The submarine is de­ 833: T=R The first part of the program in the one and one million. The player inputs stroyed when a bomb falls within 20 835: U=U+IO*COS(T) pocket computer is the Multiplication his guess on line 720. The program goes yards of the submarine. The coordinates 837: V=V+IO*SIN(T) Practice. Most of the program consists as follows: of the submarine are U and V. On lines 840: INPUT "GIVE COORDINATES simply of communicating with the player 810 and 830 they obtain their initial ran­ X,Y? ", X,Y and giving the proper response. Lines 700: PRINT "NUMBER GUESSING dom values somewhere between -1000 850: D=INTy'«X-U)*(X-U)+(Y-V)* 190, 191, and 192 give three different re­ GAME" and + 1000. The submarine is moving and (Y-V)) sponses for a correct answer. The pro­ 702: PAUSE "WHAT IS THE LARGEST the coordinates U and V are changed 860: IF D<20 PRINT "YOU HIT IT" : gram is as follows: POSSIBLE" slightly on lines 835 and 837. On line GOTO 895 704: PAUSE "MYSTERY NUMBER 10: S=.123456 850, the distance between the bomb and 870: PRINT "YOU MISSED BY"· D . YOU WISH" the submarine is measured and this dis­ " YARDS" ' • 20: PAUSE " HELLOTHERE" 706: INPUT "TO GUESS? "; L 30: INPUT "WHAT IS YOUR NAME? ", tance is reported on line 870. This section 880: PAUSE " BOMBS DROPPED="; M 710: GOSUB 500 of program is as follows: A$ 715: G=O 890: M=M+I : GOTO 835 40: PAUSE "I WOULD LIKE TO HELP" 895: PRINT "BOMBS DROPPED="· M . 720: INPUT "GUESS MYSTERY GOTO 800 ' , 50: PAUSE "YOU PRACTICE" NUMBER ".y 800: L=2000: PRINT "SUBMARINE GAME" 60: PAUSE "MULTIPLICATION "; A$ 725: G = G + I ' These programs virtually fill the 80 1: PAUSE "GIVECOORDINATES on a grid whose horizontal and vertical 70: PAUSE "WHAT IS THE LARGEST" 730: IF Y=R GOTO 760 available memory in the pocket comput­ ne use for Radio Shack's pocket X,Y" There are 39 steps of available mem­ coordinates each range from -1000 to 80: PAUSE "NUMBER YOU WISH TO" 740: IF YR GOTO 780 educate. The pocket computer is DESTROY" O and vertical coordinates for the bomb, 100: GOSUB 500 760: PAUSE "YOU FOUND IT" The seed on line 10 can be changed easy to carry and can be used on a train 803: PAUSE "MYSTERY SUBMARINE" to make the random numbers unpredicta­ and if the bomb falls within 20 units (or 110: X=R 765: PRINT "NUMBER OF or while waiting in a restaurant. It can 804: PAUSE"-IOOO = 100 THEN 450 l$ My ideas for games are limited, so and one is then multiplied by L to obtain (415) 455-9139 430: NEXT I MONUMENT COMPUTER SERVICE my next idea was a game to find a pair of a random integer between one and L. Dealers, Letterhead inquiries Invited. PhotOCOpies of (his ad are NOT valid coupons. One mystery numbers. To make this game 440: GOTO 360 coupon per purchase. ThIs coupon may be r@deemed for face value plus 15' for handlin<] Village Oat. Cenfer This subroutine is as follows: If It was received from OJStomer upon purchase of one of (he above programs. Offer void sound more interesting, the player tries 450: PRINT "THE WINNER IS FROG "; where restricted by law. P.O. Box 603 to drop a bomb on a mystery submarine. 500: N=(1T+ S) t5 I PET , Commodore Tradema~: TP.S-60 , Tandy Corp. Trademark Joshua Tree, California 92252 A mystery submarine starts somewhere 510: S= N-INT(N) 460: GOTO 300 40 Recreational Computing, September-October 1981, Issue 53 Recrea tional Computing, September · October 1981, Issue 53 41 Product News

Commodore Links Up for the unique handcrafted diskettes ... detailed patient histories and financial gram in Applesoft BASIC and produces Commodore Business Machines and but since when has software had a sea­ accounts, prints insurance fomls, and 6502 machine code from it. The object the University of Waterloo, Ontario have son? Anyway, the firm has two catalogs prepares billings and various reports. We program is claimed to run up to ten times teamed up to produce a product package of professional and educational software note that the package includes several faster than the original, interpreted ver­ of a sort that's long overdue: a consistent, ready to mail. programs to recover the data base after a sion. The compiler is priced at $200. well-integrated set of software that Prentice-Hall, under its Spectrum system crash or power failure, an essen­ makes true partners of a micro and a large Books logo, has released a list of calcula­ tial item that is often overlooked in small Turn On With TRS-80 time- sharing system. They've afflicted tor and computer books. Here are some computer software. The one-time license Just before deadline, we heard from the package with the awkward title of of the more interesting titles (with paper­ fee of $2000 includes complete source Radio Shack about their new Plug 'n "Micro-Mainframe," but - assuming it back prices). Scientific Analysis for Pro­ code. Power Controller. The controller con­ A PMC-80, configured as the master station in a network. ca n be delivered as advertised - it has far­ grammable Calculators by Harold R. REAL-TABS is an accounting and nects to the cassette jack of a TRS-80 torial independence. The edition contains reaching implications. they hope, will make it easy to fill a class­ Meek ($7.95) covers math analysis for the business in formation system for the Model I, III, and Color Computer. It The U. of Waterloo has long been a room with PMC-80's while eliminating two illuminating articles by Chris TI 58 and 59 calculators. Calculator North Star computers. Vincent D. PUlar operates under the control of the soft­ leader in the design of time-sharing soft­ the hassles involved in loading cassette Crawford head of the Atari Software De­ Clo/It by Maurice D. Weir ($8.95) doesn't claims it is good for any type of business ware that accompanies it, and can direct velopmen't Group, and reviews of 44 ware for big machines; their WATFOR software. The system is composed of a specify the calculator of interest, but but is especially designed for those who as many as 256 different remote modules and WA TFIV FORTRAN systems are master PMC- 80 with disks and a printer, Atari programs. aims at programming methods in business work with "the brokerage or leasing of to turn on, turn off, or dim. The princi­ used at many schools. They provided the connected by a simple two-wire link to a The "Special Atari Edition" is sup­ as well as science. Paul Friedman's Com­ ... real estate." In particular, the system ple used would be the same as that em­ posed to be availa ble only through A tari specifications for the system, while Com­ number of PMC-80's with more modest puter Programs in BASIC ($1 0.95) claims is said to handle up to 100 escrow ac­ ployed by the BSR Horne Controller dealers. The Atari dealers in our area modore provided the hardware and options. The master system broadcasts a to be "a fully indexed guide to over counts. It incorporates a security clear­ (which many people have modified for carry a remarkably limited stock of soft­ Waterloo Computing Systems Limited is series of programs; the user of a slave sys­ 1,600 BASIC programs recently pub­ ance so that confidential reports remain computer control) but there is no indica­ ware and seem unaware of much software developing the software. The hardware is tem captures the one wanted as it comes lished in easily accessible personal com­ so, and the author claims Hno bookkeep­ tion that Plug 'n Power's signals are com­ beyond Star Raiders and Super Breakout. based on the CBM 8032 business micro by in its turn. The whole is said to make puter magazines." TRS-80 Assembly ing input, once posted, can ever be patible with the BSR device. However, with 96K of storage and the usual CBM a useful and economical small network. If you have trouble finding software, get Langllage by Herbert Howe, Ir. ($9.95) tampered with." The system costs $175. the controller is reasonably priced at $40. the "Special Edition." If you can't find peripherals. aims to teach "all of the information any­ Finally, High Technology offers a Job The remote receivers won't break you, The software package is remarkable CompuServe Reaches Out that write to the magazine. one needs to develop machine language Costing System for the Apple II with Pas­ either, at $17 or $18 each depending on 'One valuable piece of information we programs," a fairly tall claim for its scope; it includes interpreters for CompuServe writes to tell us that cal. The system can track up to 400 jobs load capacity. _ four different programming languages, got from Purser's magazine was the fact in progress, accepting postings of all sorts their information service now has more that Atari have set up the Atari Customer Paddle a Cool Apple each in two versions: one for the micro than 10,000 registered subscribers, exclu­ of costs and producing reports that let Contact Points and one for the mainframe. The languages Service center with toll-free numbers. Two Apple add-ons came to our at­ management track progress, fine-tune esti­ sive of demonstration and employee ac­ The center is said to be ready to answer Association for Computers in Science are a BASIC (not, apparently, compatible counts, and serves more than 260 cities. tention recently. R. H. Electronics told us mates, and check profit and loss by job. Teaching, POB 4825, Austin, TX 78765. with PET BASIC), a full standard Pascal, "any Atari-related question," and to take of their "Super Fan," a quiet cooling fan orders for the newly-published Atari Software for the Private Party Atari, 1265 Borregas Avenue, Sunnyvale, a FORTRAN dialect "designed for teach­ Atari, Commodore, and Dow Jones in an Apple-colored box that hitches to CA 94086. ing purposes," and a "complete and faith­ technical manuals. the left side of the Apple case. The maker Those having an interest in genealogy Micro makers have adopted the main­ Atari Customer Services, 1346 Bordeaux fu l implementation" of APL (hip, hip, claims that Apples with more than a few and access to a CP/M or HDOS system framer's habit of making their big an­ Drive, Sunnyvale, CA 94086; toll-free calls hurray!). A relocating macro assembler circuit cards can suffer from unnoticed might be interested in ROOTS/M and nouncements at the time of the National More Information Sources welcomed at 800-538·8543 outside CA, and a linkage editor, major products overheating, leading to transient problems ROOTS89 from COMMSOFT. The pro­ 800-672-1404 in~de it. Computer Conference. Commodore themselves, are mentioned as an after­ It is ironic that the computer world that are hard to trace. The $60 "Super grams use professional genealogical con­ timed their "Micro-Mainframe" for the Commodore Business Machines Computer turns on the printed word. All of us are Fan" pulls air through the case, lowering ventions to store information on "a vir­ System Division, 681 Moore Road, King of thought. NCC and Atari came forth with a bundle This cornucopia of software (full constantly seeking printed information, the temperature of the circuits. tually unlimited number of relatives and Prussia, PA 19406; (215) 337-7100. of a~nouncements as well. Both Commo­ APL, oh boy!) is claimed to be available while personal computers are used most Peripherals Plus have produced indus­ ancestors." Pedigree charts can be dis­ COMMSOFf, 665 Maybell Avenue, Palo dore and Atari announced access to the heavily for word processing. Will comput­ trial quality joysticks and game paddles played for any individual in the file, and Alto, CA 94306; (415) 493-2184. in identical micro and mainframe (pre­ Dow Jones Investment Services database. ers drag us back to literacy? At any rate, for the Apple. Both units use a linear the relationship between any two indi­ Creative Discount Software, 256 South sumably IBM) implementations. The The packages link the personal compu ter package includes communications soft­ the press release pile gives notice of a few potentiometer that "provides linear viduals can be calculated. Robertson, Suite 2156, Beverly Hills, CA via a telephone to Dow Jones' database sources of print matter you might not control within 1/1 a of 1%" and are pack­ Hams (radio amateurs, not actors) 90211; toll-free orders through Operator ware so that programs developed locally of 6 000 stocks and financial news items. can be sent up to a big machine where have heard of, including a new journal, aged in metal cases. A set of two "Super with TRS-80's Model I or III can now go 831, 800 -824-7888 outside CA, 800-852- 'The Atari "Dow Jones Investment another software catalog, and a publisher Paddles" costs $40; a "Super Joy Stick" on the air via the computer with mini­ 7777 in it. they will execute without change. This Evaluator" program requires an Atari 800 kind of synergism is a quantum jump be­ of useful books. costs $60. mum fuss. Macrotronics produces "Ter­ Cybersoft, 433 Valley Avenue, Birmingham, with 48K of storage, a 810 disk, 850 The new Journal of Computers in minall," a package of hardware and soft­ AL 35209. yond simple time-sharing as provided by interface, and 830 Modem The program Software for the Professions The Source et a1.; it makes the responsive­ Science Teaching aims to be "a forum ware that "allows the operator to be on Dental Computer Newsletter, E. J. Neiburger costs $100. for the exchange of information about Two items relating the profession of the air receiving and transmitting Morse Editor, 1000 North Ave., Waukegan, IL ness of a personal computer and the awe­ The Commodore "Dow Jones Port­ 60085. some abilities of a big machine equally teaching science with computers." It is Dentistry to small computers came our or RTTY in minutes." The hardware box folio Management System" runs on a PET High Technology Software Products, POB and simultaneously accessiJ?le. published by the Association for Comput­ way recently. The Dental Computer plugs into the receiver headphone jack 2001 or Commodore 4032 or 8032 with ers in Science Teaching with backing Newsletter is an international publication and into the transmitter CW key jack or 14665, Oklahoma City, OK 73313; (405) One caution: while Commodore aims 32K dual disk drive unit, and modem. 840-9900. for delivery in "late 1981," it seems like­ from the University of Texas. A year's for "dentists, physicians, and office man­ Morse, or in to the microphone connector Com'modore wants $150 for their soft- subscription (four issues) costs $7. The agement people who have interests in of­ to send FSK tones. The software brings Macrotronics, 1125 N. Golden State Blvd., ly that such an ambitious package could ware. Turlock, CA 95380; (209) 667-2888. suffer deadline slippage. Still, universities editor is Gary Marks, and he's looking for fice computers." They don't give the pub­ it all to the screen and keyboard. Printer papers right now. lication interval, but a year's subscription output is supported. Micromedia, 61 South Lake Avenue, that are planning their computing moves Pasadena, CA 91106; (213) 795 -9646. for 1982 and beyond would do well to in­ Atari and Purser Creative Discount Software - strange is $ 12. Finally, users of practically any For some time, Purser's Magazine has name, that; how creative can a discount Meanwhile, Cybersoft has produced Apple now have access to what is Peripherals Plus, 39 East Hanover Ave., vestigate the "Micro-Mainframe." n Morris Plains, NJ 07950; (201) 540-0445. performed the valuable service of review­ be? - is a software retailing firm. Their version 5 of their Dental Billing System, claimed as "the first true compiler" for ing and advertising personal software. release affords an interesting glimpse into claimed to be "the most comprehensive that machine. MicroMedia told us about Vincent D. Puzar, 5905 Gulf Blvd., St. Pete Beach, FL 33706; (813) 360-7577. PMC Loads Down Robert Purser has now produced a the way the software market is develop­ software system available for dental prac­ the Applesoft Compiler, written by Personal Micro Computers makes the "Special Atari edition" of the magazine ing: "the firm ... has just completed its tices." The package consists of 29 pro­ Jonathan Fiten and "published by the R. H. Electronics, 3125 19th Street, Suite 173, Bakersfield, CA 93301. PMC-80, which they call "a work-alike and, although the publication has c1ear~y pre-season major software purchases," grams written in CBASIC for CP/M sys­ Hayden Book Company," so we're not received a lot of patronage from Atan, they say. We picture the buyers, ventur­ tems; all functions are accessed through quite clear on whose product it is. Re­ Spectrum Books, Prentice-Hall Inc., Engle­ to the TRS-80 Model I." They've devel­ wood Cliffs, NJ 07632. oped a simple local network system that, Purser seems to have maintained his edi- ing into the quaint native bazaars, looking menus. It handles group practices, keeps gardless, the compiler takes a source pro- 42 Recreational Computing, September-October 1981, Issue 53 Recreational Computing, September· October 1981, Issue 53 43 ~, - v~------· ,III ! \ il I I ,i ! i

Too many of us have been confused by complicated and metic in binary when we are preparing data for the computer, Now all possible combinations of three bits are used to drawn-out explanations of number systems. It is a subject we must find a way to represent our decimal digits as groups, This base 16 syst~m, in quite common use today, is r~p!esent a number, but they can only represent base 8 (octal) most of us prefer to forget as quickly as possible! But in the or strings, of bits. There are several ways this can be done. The known as the hexadecwzal system. This is another way to dIgItS. Th,erefore, before converting our number, for example world of computing, if one wants to get involved with more most obvious way is to conv ert each decimal number into its represent our decimal numbers with no waste of bit combina­ 347, to bmary. we must first convert it to octal. This is accom­ than a super!iciallevel of programming, he soon rnns into bi­ binary equivalent according to the following table: tions. We use repeated divisions to convert from base 10 to plished by repeated divisions by eight, as follows. nary. octal and hexadecimal notation. Author Bruey presents base 16, just as we did to convert from base 10 to base 8: us with this article which gives a clear explanation of the sub­ Base 10 Base 2 0 remainder 5 ject. Keep it on file - even if you don't need it now, there is 0 0000 0 remainder 1 I certain to be a time when you will find it handy. 8 5 remainder 3 = 533, I 0001 16 remainder 5 15B" 2 0010 8 43 remainder 3 16 21 remainder B iI 3 0011 8 347 he number system we use in our day-to-day work is the 4 0100 16 347 i decimal, or base 10, system When we use a number, for 5 0101 I example 1846.32, a place-value system is implied. That Therefore, 347), 0 = 533)" which can be checked by expand­ T 6 OlIO mg: is: 7 0111 2 0 1846.32= 1*103 +8*102 +4*10' +6*100 8 1000 533ls = 5*8 + 3*8' + 3*8 = 320 + 24 + 3 = 347)'0 Ii + 3*10-' + 2*10-2 9 1001 s~ ~471 0 ~ .15B I6. Now we can represent our base 16 number I dIgIt- by-dIgIt as a binary number just as we did in the BCD The base 10 system' is generally accepted by the industrial na­ Then we could represent the number 347 as We can now convert 533 to binary the same way that we con­ and Octal cases: tions of the world as the common number base. verted 347 to BCD: 347 The early designers of computer systems, those responsi­ 5 B 5 ble for integrating the hardware and software aspects, found 0111 3 3 0011 0100 0001 0101 lOll that the most economical approach was through the use of 101 011 011 switching circuits. These circuits could ultimately be reduced The bit string that results from representing decimal num­ bers by converting each digit individually to its binary equiva­ to a series of "on-ofP' decisions; that is, a switch was either on . Note that the binary representation is the same as it was or o ff, there was a hole in a card at a particular place or else lent is used in some computers, especially for COBOL or as­ This gives us a true binary representation of the number 347 ill the octal case, except for the leading zeroes in the base 16 there wasn't, or a relay was either open or closed. Because of sembly language programming. This r~presentation of a deci­ since we see that ' mal number as a bit string that can be used by the computer is case. The ~ase 16 representation is therefore a true binary these hardware considerations, computers were (and still are) 101011011), = 256 + 64 + 16 + 8 + 2 + I = 347), 0 representatIOn. Also note that, using powers of 16 as we used designed to work with binary numbers, called binary-coded-decimal (BCD) representation. This cod­ ing scheme has one major shortcoming: if you examine the With this representation, we have no unused bit combinations. powers of 2 and eight in the binary and octal cases we convert While the decimal system uses I 0 different digits (0, 1,2, I5B to decimal as ' 3,4, 5,6, 7,8,9) to represent all numbers, the binary system base 10 to base 2 conversion table above, you will notice there A further look into the base 10- base 2 conversion table 2 0 requires only two. For convenience, these two symbols were are some combinations of bits that never occur. For example, might lead us to investigate a way to use the 6 unused four- bit 15 B, 6 = I *16 + 5 *16' + II *16 = 347, 0 chosen to be the digits 0 and I, The value of a string of these the string 1110 does not represent any digit in the BCD combinations. To do this, we could need to defme symbols to binary digits, or bits as 'they are called, is determined in the scheme. take us from 10 to 15 , since 15 is the highest number that can same way as our decimal (base 10) example. One way to eliminate the problem of wasting such bit be represented with four bits, Le., 15) 10 = 1111 h. combinations is to drop the ditits 8 and 9 from our fable, leav­ We will arbitrarily choose the letters ABC D E and F 1101.11), = 1*23 + 1*22 +0*2' + 1*20 + I *r' + l*r2 ing us with a table of base 8 (octal) conversions: to be our additional symbols, so the table willl~ok like:' In summary: = 8 +4+0+ I +.5 + .25= 13.75 1. To convert from base 10 to base x, keep the remainders Base 8 Base 2 There are three things for your to notice in this example: Base 16 Base 2 Base 16 Base 2 from repeated divisions by X. These remainders in the re­ 1. The use of the subscript to represent the number system 0 000 verse order, will be the required number in base .:.. 0 0000 base, i.e. 110 represents a base 2 (binary) number and I 001 8 1000 2. To convert from binary to octal or hexadecimal divide the 2 1 0001 110 represents a base 10 (decimal) number. 2 010 9 1001 bits into groups of either three (for octal) or fou; (for hexa­ 10 2 0010 2. The point (.) in the bit string example is called a binary 011 A 1010 decimal). Then convert the groups to the proper octal or 3 3 0011 point, not a decimal point. 4 B lOll hexadecimal character. 100 4 0100 3. The example above shows the method of converting a C 1100 3. To convert from octal or hexadecimal to decimal, use the 5 101 5 0101 binary number to a decimal number. D 1101 method of powers of eight or sixteen as shown in the 6 110 6 0110 Since we do not want to be required to do all our arith- 7 III E 1110 examples. 7 0111 F IIII • 44 Recreational Computing, September-October 1981, Issue 53 Rec reational Computin g, September· October 1981, Issue 53 45 ,.. . .~ i I IClassifieds i' ! I EDUCATIONAL SOFTWARE tions, 1603 Solano, POB 7108, Berkeley, Electronic Firms. Please contact Merrie PET "Talks" through audio tapes teach­ CA 94707. Vander Mel & Assoc., In c. (a specialized ing BASIC and simple PET programming recruiting firm for technical profession­ for elementary students. Written by ex­ PUBLICATIONS als). 3333 Bowers Avenue # 130, Santa perienced classroom teacher. Used two MICRO MOONLIGHTER NEWSLET­ Clara,CA 95051 (408) 727-1855. years in classroom with great success. TER is the only publication devoted !NEW! Individualized - minimal supervision by exclusively to aiding YOU in the creation, Classified Ad Space Available. Write to: teacher required. Suitable for grades 3 to building and maintenance of your own Recreational Computing, Box E, Menlo 9. Activity sheets included. $57.50 for 5 home-based business using your micro­ Park, CA 94025. tapes (lO lessons) and activity sheets. system. $25/year U.S., $29/yr Canada California residents please add 6% sa les from the publisher: 1. Norman Goode, Advertisers Index tax. Frances I. Putnam, P. O. Box 605, 2115 -DO Bernard Ave., Nashville, TN Chula Vista, CA 920 I O. 37212. ASAP...... 4 ASCII...... Inside Front Cover Avant Garde Creations ...... 46 GAMES SOFTWARE FOR SALE Harry Briley...... 41 BEST CROSS WORD GAMES ON TAPE! Professional FORTH development system Oassifieds ...... 46 BEAT PAR-21: For Kids 7-12. Encour­ for the Apple. Includes FORTH Kernel, Computing Teacher ...... 39 ages dictionary exploration, builds vo­ memory to memory meta compiler, CRM/McGraw-Hill...... 23 cabulary. Two levels of pla y $ 19.95 6502 assembler, editor, file system Dilithium Press ...... •... . 47 BEAT PAR-36: For ages 12-adult. Any (supports ISAM, Hashed and Random Electronics Specialists ..... 22 access files) Name and link stripping Huntington Computing...... 29 number can play. Exasperating Some­ Imprint Software...... 23 times, funatalltimes!.... $24.95 vocabulary_ Corvus drive I/O drivers. In formation Unlimited BEAT PAR-72: A challenging version for Note: All source code included. No Software ...... Outside Back Cover crossword fans who know you don't visit royalties. In ternational Computers; P. O. J & S Software ...... 39 anim als at a XU! ...... $ 29.95 Box 397, Mt. Arlington, NJ 07856 ; Krell Software ...... 15 All tapes are TRS-80 Level II, 201/663-1580 after 6:00 P.M. ~1icro Leamingware.. . . •...... 3 L Models I and Ill. Monument Computer...... 41 COD Orders: 800/227- 16 17, ext 591. In POSITIONS AVAILABLE Pacific Exchanges...... 7 Dan Paymer ...... 22 California call: 800/772 -3545 ext 591. Microprocessor Programmers and Soft­ Theisis ...... 37 Computers for Everybody Take AIM: Volume One MAIL ORDERS: RoUingwood Publica- ware Engineers for Santa Clara Valley ~------~ Jerry Willis and Mer! Miller James H . Clark This fun-to-read book covers all the things you This lab and learning manual for the AIM-65 and r should know about computers. If you're anxious to other 6.502 microcomputers includes computer P.O. Box 30160-N Eugene, OR 97403 buy one, use one or/'ust want to find out about precautions, pr?~ramming basics, and 30 fully them, read this book irs!. documented utility and game programs which r ISBN 0-918398-49-5 $4.95 teach math, data handling, simulation and more. III ISBN 0-916460-29-0 $16.95 ZES Microsoft FORTRAN Year of the Robot THE UlTImATE IN compUTER AIDED INSTRUCTION Paul M. Chirlian Wayne Chen CREATE LESSONS IN ANY SUBJECTS. NO PROGRAMMING KNOWLEDGE NECESSARY. Here is the the book for you microcomputer users who want to implement FORTRAN on your ma­ This thought-provoking book illustrates how a ZES IS NOT A LANGUAGE BUT A COMPLETELY MENU-DRIVEN AUTHORING SYSTEM WITH: chines. Even if you've never used FORTRAN be­ ~ob ot encr.oaches upon the turfs of religion, moral­ • HI· RES GRAPHIGS fore, you will be writing and running FORTRAN Ity and philosophy, teach ing us how to behave. • COLOR AND ANIMATION programs almost at once. ISBN 0-918398-50-9 $7.95 • CARTESIAN GRAPHS ISBN 0-918398-46-0 $14.95 • HINTS Small Computers for the Small • COMMENTS DemoPkg.$10.OOI How to Get Started with CPIM Businessman • BRANCHING CAPABILITIES WITH ELABORATE STUDENT RECORD KEEPING Complete System $250.00 1 I Ca r! Townsend Nicholas Rosa and Sharon Rosa ZES fOR 8USINESS One of the world's most popular operating sys tems If you're ever considered a computer for yo ur bus­ • Lets you quickly and easily create computer aided training/instruction modules. is ~xp lained in. simple terms. Includes a handy iness but didn't know where to turn, this is the • Great for on-the·job training in all situaiions where personnel can't be spared for instructional gUIde o~ shoppmg for an operating system, a glos­ book that will arm you with all the information purposes or to supplement the efforts of vocational instructors. sary, a list of hardware manufacturers supporti ng you'll need to make an intelligent, cost-effect ive CP/ M and a list of major CP/ M software. decision. • A picture is worth a thousand words. With ZES you can create diagrams that can be studied at ISBN 0-918398-32-0 $9.95 ISBN 0-918398-31-2 $12.95 any time as part of instruction. • May be used to create material for general informational terminals, such as can be used in vocational counseling, etc. THE COmPLETE mAILING LA8EL & fiLING SYSTEm From dilithium Press • Binary sorting for 2 second access • Sorts all files alphabetically or by zip-code and writes alphabetical and zip directories • Prints out regular mailing labels with optional added lines Write or call for free catalog! 800-547-1842 • Prints out labels in file·sequence, alphabetical or zip-code order Most bookstores and computer stores carry our books. Ca li us on • Range sorts, field sorts, or character·code sorts individually or concurrently - very dynamic our toll free number and we'li teli you the o ne nearest you. • User formatted fields dd,th,um Press, P.O. Box 606, Beaverton, OR 97075 • Prints out sorted 80-column (or more) formatted address lists, phone lists, or user formatted lists, in file, zip code or alphabetical order • Multiple (or 2 level) COUNT/SORTs 1$75.QQL