softalkv2n03nov1981

¥ & #) , — / } ‘ ‘ . ith V7 ae me ee BT OG Poe a) Mes oe, from darkest dungeons to Ultime a fantasy role-pla designed by LORD BRITISH wit. « ei Computer Compan Chairman John Haller Publisher Al Tommervik Editor Margot Comstock Tommervik Managing Editor Craig Stinson Art Director Kurt A. WahIner General Manager Mary Sue Rennells Editorial Associate Jean Varven Assistant Editor Melissa Milich Product News and Copy Editor Carol James Contributing Editors Assembly Language Pascal Business Apple CP/M Apple IIT Hardware Investing Basic Solutions Special Projects Roger Wagner Jim Merritt Peter Olivieri Greg Tibbetts Taylor Pohlman Jeffrey Mazur Kenneth Landis Wm. V. R. Smith Donna Siebert Greg Voss David Hunter Kimberly Curling Ron Remnells Robert Mann Miriam Gamble Wm. V. R. Smith Ken Williams ‘Al Tommervik Ad Coordinator Circulation Art Assistant Systems Advertising Sales 213-980-5074 Gover design by Kurt Wahiner: photo courtesy of United States Forest Service, Pasadena, California. ‘Composition by Photographics, Hollywood, Call: fornia. Printing by Volkmuth Printers, Saint Cloud, Minnesota, pple is a registered trademark of Apple Com- puter ive., Cupertino, Californias UCSD Pascal ie a trademark of the University of California at VisiCale Sunnyvale, C SoftCard is a tra jemark of Microsoft, Bellevue, Washinj Softail, Volume 2, Number 3. Copyright «1981 by Softalk Publishing Inc. Ail rights reserved. ISSN:0274-9629. Soffalk is published monthly by Softaik Publishing Inc., 11021 Magnolia Boulevard, North, Hollywood, CA 1601. ‘Telephone, (218) 980 5074. Second-class postage paid at North Hollywood, Be ee Postmaster: Send address changes to Softalk, 2021 Magnolia Boulevard, North Hollywood, CA 1601. Subseriptions: Complimentary to all owners of Apple computers in the USA. If you own an Apple, but you're not receiving Softalk, send your name, address, and Apple serial number with a request for subscription to Softalk Circulation, 11021 Magnolla Boulevard, North Hollywood, CA 91601. Softalk Is to- tally independent of Apple Computer Inc.; sending your warranty card to Apple Computer will not in- form Softalk of your existence. Non-Apple owner subseriptions for one year: $12. For the convenlence of business and schools in which several staff mem- bors share an Apple and would like Individual copies f Softalk, multiple subscriptions to the same. ad- Gress are availaale at lower rates: two through five, $9 each; more than five, 87 each. sues: $2 through February 1981; $2.50 November and December 1980 and Jan- uary and March 1981 issues are sold out. Softalk will send you a back issue of your choice free (available issues only) for the name, address, and serlal num- ber of each Apple owner you can find who isn’t al- ready receiving Softalk. Problems? If you haven't received your Softalk by the tenth of the month, or If you have other prob- Jems with your subscription, Ron Rennells or Kim- Berly Curling can help ut. Call 218) 980.8099, ‘Moving? Send new address and old to Softalk Cir- culatfon, 11021 Magnolla Boulevard, North Holly- ‘wood, California 91601; telephone, (213) 980-5099. iego. trademark of Personal Software, fornia. CO Nr en T $ Exec Broderbund: Saga, Star Craft, and family & Success AL TOMMERVIK . A Man of the Future—Steve Beck Apples among the Acorns with U.S. Forest Service MELISSA MILICH An Apple in Psychotherapy KATE DICKSON and ZEV WANDERER ............- Telecommuting: Is the Central Office Almost Obsolete? DAVID HUNTER .............00005 The New Applesoft Compilers: What For? ROGER WAGNER [ee | 155 ES Page &t Time after Time: Apple Clocks, Port 2.........0+e+ee+e+++ RICHARD KAAPKE 77 Running against the Apple: Timing Races ....... .....DAVID HUNTER 81 Give Your Apple a Little RAM: RAM Cards...... . .... JEFFREY MAZUR 84 A Haunted House Run by Apples ..........0-e0eeeeeeeee ss MELISSA MILICH 132 Ada: They Named a Language after Her .........+.-2.++++++ CAROL JAMES 148 Use Your Apple To Find Your Business’s Worth ..............STEPHEN PARRISH 166 Microprocessor Chips for Your Apple .........+e+eeseee++++ JEFFREY MAZUR 174 Art Gollery: Contest .. 2 Tradetalk .. .+.49 Mind Your Business: Cantest Winners . 4 Ventures with Peter Olivieri ............-160 Open Discussion .........+...-6 Marketalk: SoftCard Symposium “The Third ‘Boek Greg Tibbetts aie We Toylar Pahiman....... Jim Merritt . see teens 21 Assembly Lines: Buttanwaad Apples: Roger Wagner............41 Kenneth Landis ....... PRE V The Basic Solution: Wm, VR. Smith .. Beginners’ Corner Craig Stinson 34 Newspeak . Softalk Presents -137 the Bestsellers . EW 3 my Decembe® alliance «++ Softalk’s Secand ‘Waliday GiffGuide . . . Laaking Farward: New Year's Predictians .. . Exec Micralab = Christmas Dream: The World's Largest Apple System .. . Spotlight: Jim Sodlier— Retailer, Book Publisher, Saftware Magul Apple Fartran Examined ... and - -187 Sentlent .. Slerra Software .......cs5 Sirlus Software ... L & 8 Computerware .... Masterworks Software | 14, 16, 27, 47, 71, 72, 74, 128, 149, 158, 170, 185, Cover 4 Orange Mlero Osborne/McGraw-Hili Output... Software Technology . Southeastern Software Southern Callfornla Research Gi Southwestern Data Systems. -.-43y 68; 145 Spectrum Software .......0005 Passport ...sicciciicseessesscesseesee20 Stellation Two Peay : Stoneware . Penguln (formerly Micro Co-op) « Strategie Simulations ... Personal Software .. SubLogie . precera Powersolt . Symtec ...... 68 Intelligent Computer Sysiems........1.28 Professional Medical Software ..00....101 Synergistic Software ..c0cccc.s0038 us Interactive Mleroware ...... Prometheus ....... Syntaurl ...... Ralnbow Computing’. Thunderware . Concepts & System: Context... .e.-. Continental Softwar iK Enterprises RH Electronles ......0.- cscs 1-105, Riverbank Software . Saturn Software . Vital Information s22.c00sccsc060280; 8 West Slde Electronics 118 Yucalpa Software ......0 ‘ea 2 CONTEST: SLIPSHOD SOFTWARE Presents @ TOFIALK NOVEMBER 1981 sign a software package! U.S. Postal Service Statement of Ownership and Circulation (Required by 39 U.S.C, 3685) 1. Tithe of publication: Softalk A. Pubitcation No. 02749629 2. Date of filing: October 1, 1981 3. Frequency of issue: monthly 3A. No. of issues published annually: 12 3B, Annual subscription price: Free to Apple computer owners 4. Location of known office of publication: 11021 Mag- nolia Blvd., North Hollywood, Los Angeles County, Cali- fornia 91601 5. Location of the headquarters or general business of- fices of the publishers: 11021 Magnolia Bivd., North Hoity- wood, Los Angeles County, California 91601 6, Names and complete addresses of publisher, editor, and managing editor: Publisher: Ai Tommervik, 11021 Magnolia Blvd., North Hollywood, CA 91601 Editor: Margot Comstock Tommervik, 11021 Magnolia Blvd., North Hollywood, CA 91601 ‘Managing Editor: Craig Stinson, 11021 Magnolia Bivd.,. North Hollywood, CA 91601 7. Owner (if owned by a corporation, its name and ad- dress must be stated and also immediately thereunder the names and addresses of stockholders owning or holding 1 percent or more of total amount of stock. If not owned by a corporation, the names and addresses of the individual owners must be given. If owned by a partnership or other unincorporated firm, its name and address, as well as that of cach individuai must be given. If the publication is pub- fished by a nonprofit organization, its name and address must be stated.) : Softalk Publishing Inc., 11021 Magnolla Blvd., North Hollywood, CA 91601 Robert Comstock, 11921 Magnolia Bivd., North Holly- wood, CA 91601 Wiliam Depew, 10432 Burbank Blvd., North Holly- wood, CA 91601 John Haller, 11021 Magnolia Bivd., North Hollywood, CA s1e01 John Mitchell, 10432 Burbank Bivd., North Hollywood, CA 91601 Wiiilam ¥. R. Smith, 10432 Burbank Blvd., North Holly- wood, CA 91601 Softape, 10492 Burbank Blvd., North Hollywood, CA #1801 Margot Comstock Tommervik and Al Tommervik, 11021 Magnolia Bivd., North Hollywood, CA 91601 Kurt A. Wahiner, 11021 Magnoiia Blvd., North Holly: ‘wood, CA 91601 8. Known bondholders, mortgages, and other se- curity holders owning or holding 1 percent or more of total amount of bonds, mortgages or other securities (If there are none, so state) None 9, For completion by nonprofit organizations author- ized to mati at special rates (Section 132.122, PSM) Not ap- plicable 10. Extent and nature Average no. Actual no. of circulation copies each coples of Issue during single tssue preceding 12 published months nearest to filing date A. Total no. copies printed (net press run) 43,283. 47,500 Paid circufation 1, Sales through deaters and carriers, street vendors and counter saies 4443 6.400 2. Mail subscriptions 0 ° C. Total paid cireutation (sum of 10B1 and 10B2) 4,448 6,400 Free distribution by mail, carrier or other means, samples complimentary, and other free copies 38,000 40,589 E, Total distribution (Sum of C and D) 42,443 40,089 F. Copies not distributed 1, Office use, left over, K unaccounted, spoiled after printing 500 250 2. Returns from news agents 340 201 G. Total (Sum of E, Fi and 2 should equal net press run shown in A) 43,283 47,500 11, I certify that the statements made by me above are correct and complete. Ai Tommervik, Publisher ART GALLERY The wonderful thing about creating art on the Apple is that you don't have to be artistically talented to get a good re- sult. You can just have fun and end up with a professional-looking work. This month's contest is intended to pamper the artist in all of us. The idea is to design a poster or pack- age for your favorite program, real or imagined. The contest has two divisions. The first division is for entries designed on and printed from an Apple. The sec- ond division is for those of you who don't have access to a printer with graphics ca- pability; entries for this division may be executed in any two-dimensional me- dium and need not be computer gen- erated. Six entries in each division will be se- lected by Softalk's staff on the basis of originality, applicability of design to product, cleverness, and eye appeal. The twelve finalists will be printed in Softalk, at which time Softalk's readers will have the opportunity to vote for their favorites to determine the two final winners. The first-place winner in each divi- sion will receive $100 worth of goods pro- duced by Softalk’s advertisers. The five runnersup in each division will receive $10 credits at their local computer stores. All entries will be judged in black and white for the preliminary round. The twelve semifinal winners will be asked to submit printable-quality color photos or printouts of their works done on the com- puter or color versions of their hand-done art, which will be the versions printed in Softalk. Send your entry with the coupon be- low to Softalk Art Gallery by December 15, 1981. Name: Address: ___ City/State/Zip: Phone: Dealer: Prize You'd Like: _____ Your Autograph: Mail this coupon with artwork to Softalk Art Gallery, 11021 Magnolia Boulevard, North Hollywood, CA 91601, by Decem- ber 15, 1981. as medfly de-buggers who defeat the bugs in the three gardens beware, as they must face a | ee 7 ec formation with a deadly flight pattern! : Defeat the Bug Attack at your local computer store. _ | Brought to you by: Written by James L. Nitchals =™ Bug Attack requires Apple Il, 48k. (13 or 46 sector). = *Appleis a Trademark of Apple Computer, Inc. PjCAVALIER COMPUTER = P.O. BOX 2032 — DEL MAR, CA 92014 — (715) 755-8143 aah oo @ SOFTALK NOVEMBER 1981 LittleCrypt Winner Found Delicious Answer on Mcintosh Apple SuperCrypt. Dann McCreary's Apple still belongs to Dann McCreary. As was expected all around, no one was able to break the SuperCrypt code; but three people did some excellent spadework as a start on it and one happy person ac- tually took a flyer on a translation. Whether the latter is a “reasonable” start or not is a moot point—but we be- lieve it is because it matches the spirit and, well, it could have been close. E. N. Hendrick of Torrance, CA, whose letter—which was dated 11:21 P.M., September 15, or 39 minutes be- fore deadline—described some remark- able, deep, clear cryptological thinking, begged an extension. Brian Holland of Endwell, NY, didn't attempt a transla- tion but explained the methodology he be- lieved would have to have been used to derive the code. R. F. Lauer of Nutley, NJ, went at the problem like a detective and came closest to understanding how the process really works. Because Lauer's entry included a letter with thoughts of more general interest, you can find it in Open Discussion. Finally, Sean Walter of Kansas City, MO, is the reader who took a chance on a real trans- lation, which was: “Hello! This is SuperCrypt. If you stop at the end of the next sentence, you automatically win. You may continue to find out if the third line really says what it should, but you automatically win if you stop at this period.” All four people will receive Absolute Security disks for their honest attempts. Dann McCreary’s translation of the SuperCrypt code remained sealed in an envelope under lock and key at Softalk throughout the contest period. In the last week of September, we opened the enve- lope, and here is the translation we found: As I compose this challenge, images of mysteries, things hid- den, secret words, and obscure say- ings run through my mind. ... Solomon: “‘It is the glory of God to conceal a matter; to search out a matter is the glory of kings.... A word aptly spoken is like apples of gold in settings of silver." Pro- verbs 25:2.11 Plato, Allegory of the Cave: “When any of them is liberated and compelled suddenly to look towards the light, he will suffer sharp pains; the glare will distress him, and he will be unable to see the realities of which in his former state he has seen the shadows;"" The Prophet Isaiah: ‘‘The Lord . . who overthrows the learning of Victoria Wollner, winner of the Logical Choice onnoyne in September, chose Gorgon os one of her prizes. Wollner resides in Anoheim, Colifornio. the wise and turns it into non- sense."’ Isaiah 44:25 Distilled from Covert Action Info. Bulletin, Dec '80: The NSA in- tercepts ‘virtually all” phone calls, telegrams and telexes where one or both parties is outside the U.S., as well as many such communica- tions within the U.S. John the Apostle: ‘In the begin- ning was the word, and the word was with God, and the word was God."" John 1:1 Poe, The Gold Bug: “It may well be doubted whether human in- genuity can construct an enigma of the kind which ingenuity may not, by proper application, resolve.” David Kahn, The Codebreak- ers: “So the answers again evade the cryptanalyst, formless, end- less, the random one-time tape van- quishes him by dissolving in chaos on the one hand and infinity on the other. Here indeed the cryptana- lyst gropes through caverns mea- sureless to man.” Jesus: ‘'For there is nothing hid- den that will not be disclosed, and nothing concealed that will not be known or brought out into the open."’ Luke 8:17 “IT am the first and the last .. . and I hold the keys. .. ."" Revela- tion 1:17,18 LittleCrypt. The LittleCrypt para- graph said: ‘‘If James Bond, Mata Hari, and Napoleon Solo had used Apple com- puters, they would certainly have been called Northern Spies.” Filling into the diagram the words if, had, Mata, would, James, called, Northern, computers filled the colored boxes with the letters I, H, T, O, M, C, N, S, which comprise an anagram of the word McIntosh, the name of a variety of apple. Besides the obvious connection—Apple itself—the crypto- gram gave another clue. As the winner explained it: ‘‘Northern spy is an apple; as is McIntosh. Having the word Apple embedded in the code made the solution much easier."" Do you recognize your words, Paul Rabson of Pittsford, NY? Paul Rabson wins $100 worth of goods, which he'll pick up at his dealer, the Computer Center in Rochester, NY. Rab- son broke the code for the paragraph in the easy way: the entire sentence code was created by touch-typing the real words with hands one row above and slightly to the left of appropriate posi- tion. Several entrants wrote programs to solve the cryptogram. Because many entrants derived other real words (and some not so real) by en- tering different words in the boxes, we decided to give a $25 consolation prize to one of these entries. The random number generator chose C. William Winkler of Canoga Park, CA, whose winning entry was the word hyp- notic. Winkler will take his prize from Rainbow Computing in Northridge, CA. Other words submitted that can be made legitimately from filling in the boxes dif- ferently are acrimony, avionics, cano- pies, captains, captions, picayune, tym- panic, and unchains, None of these, how- ever, bears any relationship to the rest of the puzzle. It’s interesting that a large majority of entries that chose these words were multiple entries giving different words. Of the fifteen people who chose MclIn- tosh, only one entered more than one an- swer, and that one disclaimed his action by writing that McIntosh was the an- swer, but that several other words would also fit. ia AS Brdd, i erbund So PRESENTS oftware Ladders, take you from level to level og es The deadly, intricate dances of the space. Boeloaqnesssinoart. & ‘eNETIC ecat oie scone dene a 4 e- Sci me am | @® = } uves. yi S¢orr ae | SoimAM This finger-pounding arcade game require: ASK YOUR DEALER OR SEND CHECK OR MONEY ORDER TO: ks < Brdderbund Software * 2 VISTA WOOD WAY, SAN RAFAEL, CA 94901 © (415) 456-6424 6 OPEN Cal Pacific’s Computer Camper Reports In Thank you and California Pacific for sending me to Computer Camp. I had a great time and learned a lot. I entered a contest on the T199/4, which I had never used before, and won first prize, which was a nylon jacket. I would have liked it to be an Apple jacket but I was happy to win it anyway. I really enjoyed the camp and took all the classes I could. I took accelerated Ba- sic, graphics, robotics, artificial intelli- gence, and game simulation. I met some real nice kids and had lots of fun. It was something I never dreamed I would get to do. I couldn't believe I was really going to the camp until I actually got there. I applied to the director to work as a PA next year, so I hope I make it. If I don't, I am really happy to have been able to go once anyway. My family could never have afforded to send me and it would have taken me years to save up to go if I could. The only thing I didn’t like was that they didn't have enough Apples. Some of the kids in my cabin brought their own, so that helped. Maybe you can influence them to get a few more next time and al- so talk Apple into making them more available. ® SOFTALTK NOVEMBER 1981 DE SO Anyway, thanks again. I really was happy to go. John Brandstetter, South San Gabriel, CA Believing in Security Can Be Perilous Being an amateur cryptographer and a member of the American Cryptogram Association, I'd like to comment on Mr. McCreary's challenge cipher. First let me State that I have no desire to win his computer system, but I am concerned about his claims. Since I am not a regular reader of your magazine (I own a Commodore PET), this cipher was brought to my at- tention by a stranger who read my letter to the editor in the July 1981 issue of Cre- ative Computing. There I stated that it was dangerous for anyone not familiar with advanced cryptanalytic techniques to propose an enciphering scheme which they consider “absolutely secure." In both the preamble to the cipher and in his press releases he makes exag- gerated claims of security, which are not proved even if the challenge problem is not solved. This is dangerous since sensi- tive data might be enciphered, creating a false sense of security, while in reality it may be very vulnerable. As is generally known among cryp- tographers, security cannot rest in the se- crecy of the general system, but in the in- ability to recover the specific keys. I therefore challenge Mr. McCreary to publish his complete enciphering algo- rithm, less specific keys, if he has such faith in the invulnerability of his scheme. Lest anyone believe this to be unfair, re- member that a determined cryptanalyst with access to an Apple can get a copy of the program, and even if a listing can't be gotten, then by proper inputting to the program, the actual details of the algo- rithm can be slowly determined in a short time. An analogy is an inventor of a new “pick-proof” lock who won't dis- close its internal workings. Again, only a careful analysis can verify such claims. The statement in his flyer, that it is “theoretically impossible to decode with- out the exact duplicate key” implies that , See perhaps a “‘one-time-pad’’ system is used. This involves using an infinite list of perfectly random numbers as the keying sequence, which is used only once. The production of the keying sequence is im- portant, since truly random numbers are hard to compile and random number generators are easily deciphered from a relatively short segment. In addition, the key sequence must be longer than all intended messages and must be produced, transmitted, and stored under high security conditions; loss of the key compromises all informa- tion, since it can’t be retrieved. In cases such as these, one might as well store the raw information and avoid the costly en- cipherment. Such a system was aban- doned long ago by the military as being impractical under normal working con- ditions and has also been ruled out by all computer-cryptographers for similar reasons. Lest anyone assume that I'm out to “get” Mr. McCreary, let me say that I’m not. If his scheme is as good as he claims then he should certainly get all the re- wards; if it is not as good, then such soft- ware should see very limited use, since a false sense of security is more danger- ous than no security at all. Only by an un- biased evaluation of the enciphering algorithm can such a judgment be accu- rately made. Rudolph F. Lauer, Nutley, NJ Tops despite Omission I read with great interest Craig Stinson’s survey of the various home finance pack- ages available for the Apple computer. I am very well acquainted with most of the products he mentioned in both his arti- cles in April and May. Although, I must confess that I was very much disap- pointed when his review did not cover the Apple Personal Finance Manager. As I stated, I have personally tried at least 50 percent of the products sur- veyed, but none has shown the ease of op- eration I have found with the Personal Finance Manager. Like most of the products surveyed, GOTO 15 A new level of maturation of the microcomputer soft- ware industry into big business was achieved in mid No- vember when Personal Software acquired for cash the rights to the source code of VisiPlot and VisiTrend, the best- selling business graphing packages from Micro Finance Systems. No actual figures on the sale were released, but the transaction was known to be in the seven-figure range, mak- ing it the largest cash transaction in microcomputer his- tory and the largest buy of any kind of rights to source code. VisiPlot and VisiTrend had previously been marketed by Personal Software under exclusive marketing agreements. Software Sale Sets Big Bucks Record Other large sales of microcomputer software have ei- ther involved only finished product or have involved the en- tire publishing company. When Peachtree bought Magic Wand, it also assumed the ongoing business of the publish- ing company. Apple Computer has made several six-figure buys of finished product that do not include any rights to source code. In making the announcement, Mitch Kapor, president of Micro Finance Systems and author of the two software packages, indicated that most of the proceeds from the sale would be pumped back into Micro Finance to fuel research and development of new software products. aa NOVEMBER 1981 SOFTAINK , e. 4 PFM utilizes single-stroke entry as much as possible. It takes into account all cash, credit card, and check expenses. The program allows for establishing twenty- four budget codes to account for these ex- penses. (This can be somewhat limiting, depending upon the size of the family budget.) The report formats allow for numer- ous reports ranging from monthly to yearly comparisons, complete with graphs, and yearly totals. The program allows for up to two hundred entries per month, a sum which I have found to far exceed my family’s need—by approxi- mately 75 percent. One feature the PFM allows that I have not seen with other programs is a feature that allows a thirteenth month carry-over into the new year. As I stated, I think the features of this program should be brought to the atten- tion of Apple owners. One last note, I really enjoy your col- “umns on VisiCalc and assembly lan- guage. Elton R. Shorter, Columbus, OH Down in the Dumps I recently purchased an Epson MX-80. I am very pleased with the printer but found the instruction manual left some- thing to be desired as I am an Apple own- er. Can you believe it contains a screen dump program for the TRS-80 but not for the Apple? No offense meant for TRS-80 owners. As an Edu-Ware representative in my spare time (is there such a thing’), I get to travel most of the state of Florida visit- ing computer stores (a dream come true). In all my travels, I was unable to find a simple screen dump program. Out of necessity, I decided to sit down one evening and write my own. Since ne- cessity is the mother of invention—Eu- reka!—after four short hours, I had it. Seemed more like thirty minutes! I have enclosed a copy for your diligent peru- sal. You may feel free to publish it for the benefit of all those poor souls out there that just bought an Epson (or other print- er) and want to be able to dump their Ap- ple screen using this carefully thought- out subroutine. It can be appended to any Basic program and called with a control- 13) A brief description of how it works may be in order. Line 33000 begins the subroutine and sends the action to line 33020 where the printer interface is told to wake up and get ready and the screen scroll is turned off. Lines 33030 to 33050 then take over the identify screen line lo- cations and put them in the correct order for the printer. Line 33010 is a GOSUB in the sub. This line identifies individual locations across each line on the screen and peeks them for the printer (neat, huh?). The return at the end of the line sends us back to the next I, which then sends us back through Pe GU 15 Or Ech Bel On the GOSUB 33010 as many times as we need to in order to cover all the lines on the screen (eight times for each I). After all twenty-four lines and forty screen locations in those lines have been peeked to the printer, we go to line 33060, which tells the printer interface thank you and good-bye and turns the screen back on. It works well for me and my MX-80, and I don't know why it wouldn’t work for any printer hooked to an Apple with little or no modifying. 10 REM SHH HE EO HE SE EOSEEEBEEEEF HE 15 REM * 20 REM 25 REM 30 REM 35 REM * SCREEN DUMP PROGRAM * + * 40 REM * * . BY ART CHRISTOPHER 45 REM 50 REM 55 REM 60 REM 65 REM 33000 GOTO 33020 33010 FOR J = 1 TO! + 39: A = PEEK(J): PRINT CHRS(A);: NEXT J: PRINT CHRS(13);: RETURN 33020 PR#1: PRINT CHR$ (9) “BON” 33030 FOR | = 1024 TO 1920 STEP 128: GOSUB 33010: NEXT I 33040 FOR | = 1064 TO 1960 STEP 128: GOSUB 33010: NEXT | 33050 FOR | = 1104 TO 2000 STEP 128: GOSUB 33010: NEXT I 33060 PR¥O 33070 REM. 33080 REM ART CHRISTOPHER 7/15/8) Perera a a ara) Spr ae po ep OIE IOI IO Art Christopher, Boca Raton, FL Fractious Fractions I was pleased to read Richard Cole- man’s article on the use of the Apple II by the College of Home Economics at Loui- siana Tech (August 1981). The ‘Frac- tions Maker” subroutine accompanying the article, however, violates several principles of good programming. In the interest of providing good examples of programming techniques, I think the fol- lowing remarks are pertinent. Although the program will run as pub- lished if input is made strictly as re- quested, an incorrect answer will result if a character other than ‘‘ +" is used to sep- arate the integer from the fraction; a space, for example, which is a natural way of typing a fraction. Or, try entering an integer followed only by a +. Beep! It appears that line 10060 was intended to check for this, but, since (II — 1) can never equal LEN(N$) because of the loop limit in line 10020, the If statement of line 10050 must always be true and line 10070 can never be executed—it is dead code. Now, how did such an error creep into a perfectly good piece of code, and why isn’t it immediately apparent? The an- swer is, because the subroutine is poorly structured—difficult to read through and observe the program flow. One technique that helps is to avoid multiple exits from a subroutine. In the Fractions Maker, notice that there are three lines that contain returns from this one subroutine, depending on the condi- tions found in the input string. That may not seem too confusing when there is only one subroutine, as here, but it makes for a mish-mash when you write several sub- routines in a block, which is common practice. Better to structure your code so there is a single entry and a single exit for each subroutine. If your subroutine logic really requires multiple exits, you can Goto the return line number from any earlier points from which you want to exit. The program will work the same way, but it will be much clearer when you or someone else tries to read and un- derstand the source code. Another suggestion is to make it clear in the coding where loops begin and end. The best way, when possible, is to make For . . . Next loops very short. When they stretch out over many program lines, the program flow is more difficult for us hu- mans to follow. This is especially true if you branch out of the loop via If state- ments. I enclose an example of a subroutine from my recipe management system, Computer Cuisine, which performs the same translation as the Fractions Maker. Aside from Rem statements, the two routines are about the same length. The input string is (AQ$) and the output value is (F). The input format accepts ei- ther a space or a hyphen separating the integer from the fraction. I also enclose a subroutine for frac- tional output. If decimal numbers are in- convenient to input, they are doubly so when read on a screen or printer as quan- tities of sugar, flour, or eggs. The as- sumption upon which this subroutine is based is that, in food recipes, the only fractions needed are halves, thirds, quar- ters, eighths, and perhaps fifths. Given a real number input (V), this subroutine simply separates out the fractional part if any (line 140) then iteratively assigns a string value to F'$ and tests the fraction- al real value against the midpoints be- tween successively higher fractions. The first time the test fails, program flow falls through to lines 144 and 145 where the integer part, if any, of the original value is put together with the fraction. They have landed and are taking over the city. Steadily they are making their way across the city, destroying everything in their paths. The town has been evacuated and your regiment has retreated leaving you, alone in the city, at the mercy of the aliens. The aliens have you surrounded, and laser shots fly from all directions. Your movements are confined but you haven't given up. If you're going to live, you'll have to concentrate on where the shots are coming from and where you're going because if you don’t, you'll get caught in the CROSS FIRE. CROSS FIRE is a unique new game by JAY SULLIVAN featuring HI-RES graphics and sound, smooth quick animation, and some of the best arcade challenge available anywhere. CROSS FIRE runs on any 48K APPLE JIM PLUS DOS 3-2 or 3-3 and is available now for $29. 95 on disk from your local computer store or you may order directly from...... IN-LINE systems 36575 Mudge Ranch Road - Coarsegold, CA 93614 - 209-683-6858 Nie ADD $1.00 FOR DIRECT ORDERS VISA, MASTER CHARGE, C.O.D. or CHECKS ACCEPTED NOVEMBER 1981 SOFTALK The result is the nearest common frac- tion, formatted in string (F$). Computer Cuisine also does range checking for the units of measure, ex- pressing scaled quantities in appropriate units (21/3 tablespoons rather than 7 tea- spoons, for example). It also rounds cer- tain units to whole numbers, as appro- priate, so you are not told to use 1 7/8 cans of tuna. 10 REM BBB AC HE ap bobanambone 11 REM * * 12 REM * FRACTIONS INPUT AND * 13 REM * OUTPUT SUBROUTINES * 14 REM * DEMO * 15 REM * DON RAVEY 8/1/81 * 16 REM * * 17 REM SOR HOOE ER ECee aE 18 REM 20 TEXT : HOME 99 GOTO 199: REM uSUBROUTINES:: 100 REM OUTPUT FRACTIONS SUBR: 101 VI. = INT (VF = V — ay 102. IF F > .0625 THEN FS = “1/8”: IF F > .1625 THEN FS = "1/5": IF F > .225 THEN FS = 1/4": IF F > .291666667 THEN F$ = "1/3": IF F > .354166667 THEN FS = "3/8": IF F > .3875 THEN F$ = "2/5" IF F > .45 THEN FS = “1/2 GOTO 104 103 GOTO 105 104 IF F > .55 THEN F$ = "3/5" IF F > 6125 THEN F§ = "5/8": IF F > 645833333 THEN FS = 2/3": IF F > 708333333 THEN F$ = "3/4": IF F > .775 THEN FS ="4/5": IF F > 8375 THEN F§ = "7/8": |F F > 9375 THENF$ = “VI = VI +1 105 VIS = STRS (VI): IF VI = 0 THEN VIS = """ 106 FS = VIS +" + FS: RETURN 108 REM 110 REM INPUT QTY SUBR: 111 FOR | = 1 TO LEN (AQS):T$ = MID$ (AQS,I,1) 112 IF T$ = “.” GOTO 115: REM DECIMAL 113 IF TS = "/" OR T$ =“ OR T$ = “—" GOTO 116 114 NEXT 115 F = VAL (AQ$): GOTO 124: REM DECIMAL OR WHOLE NO., NO FRACTION 116 IF T$ = “/" THEN FW = Oil = 0: GOTO 118: REM NO WHOLE NO. 117 FW = VAL ( LEFTS (AQS, — 1) 118 FOR J = 1 TO LEN (AQS): IF MIDS (AQS,J,1) = “/" GOTO 120 119 NEXT 120 NFS = “““FD$ = 121 FOR K = | + 1 TO J:NFS =NFS + MIDS (AQS,K,1): NEXT : REM NUMERATOR 122 FOR K = J + 1 TO LEN (AQS):FDS = FDS + MIDS (AQS,K,1): NEXT : REM DENOMINATOR 123 FF = VAL (NFS) / VAL (FDS):F = FW + FF 124 RETURN 199 REM \AIN PROGRA\ 500 PRINT “THIS IS A DEMO PROGRAM FOR FRACTION”: PRINT “INPUT AND OUTPUT SUBROUTINES.” 510 PRINT : PRINT “DO YOU WANT TO TRY THE INPUT OR OUTPUT” 520 POKE 34,5: REM SET TOP OF TEXT WINDOW 530 VTAB 5: CALL — 868: PRINT “ROUTINES, OR EXIT (I, O, OR X)? “;: GET AS: PRINT AS: HOME 540 IF A$ < > “I” AND A$ < > “O” AND AS < > “x” THEN 530, 550 IF AS = “I” THEN PRINT : PRINT “INPUT A NUMBER ... EITHER DECIMAL OR": INPUT “FRACTIONAL —<LIKE: 15 2/3 > ":AQS: GOSUB 110: PRINT : PRINT “THAT'S ";F: GOTO 530 560 IF A$ = “O” THEN PRINT : DECIMAL NUMBER, > "Ne GOSUB 1 PRINT “INPUT A. INPUT “<LIKE: 27.2865 RINT : PRINT “THAT'S “,F$: GOTO 530 570 TEXT : END Don Ravey, San Mateo, CA Mixing Apples and... Ienjoyed Jeff Mazur’s article ‘‘Terminal Data.” I truly hope you can shed some light on my problem. I live in New York City and have an Apple II with RAMCard, two disk drives, and Hayes Micromodem. My son lives in Binghamton where he bought a Radio Shack Videx terminal. This terminal produces thirty-two charac- ters. It has a built-in modem. The Apple produces forty characters. He succeeded in accessing the Apple and booted a disk. However, his readout on the TV screen was a wraparound on the same line. Undoubtedly, the two sys- tems are not compatible. Are there any software programs to make them work? Certainly would ap- preciate your consideration in this mat- ter. Irwin Horowitz, Bayside, NY Direct Clutter {To Greg Tibbetts:] Your new column in Softalk is long overdue and excellent in every respect. Hope you will continue to enlighten us SoftCard CP/M users and expand to other topics such as Microsoft Fortran and the Z80 assembler develop- ment package. I am having an annoying occurrence with my CP/M, which may have already been corrected in the new version, which I have not received. Occasionally, especially when using CONFIGIO, I am getting files in the directory that Iam un- able to delete. While of no concern as far as storage is concerned, nevertheless, it clutters the directory. Any suggestions? Would also appreciate it if you could cover in your column in detail how to en- ter more than a single assembly pro- gram to be used concurrently at the same hex address. Henry Lustig, Vergennes, VT A Policy Worth Applauding In Allan Tommervik's article on Hayes Microcomputer Products (September 1981 issue), he mentions that Hayes has . the most liberal warranty program in the Apple marketplace—two years.” You might be interested in . . . our three- year warranty for our MC1 and MC16 Music Cards for the Apple. Usually, soft- ware is not covered by warranties, since a program bug may not be considered a manufacturing defect. To eliminate any doubt, our one-year warranty on soft- ware guarantees the software will work as described in the owner’s manual. I know that ALF has very high goals for product quality, and as a Hayes Micromodem owner, I applaud Hayes's quality goals and long-term warranty. I hope more companies will begin to recog- nize the importance of quality and start offering longer warranties than the usual _ limiage storaue by 30 70%, oo 17 by Mark Pelezarski Brand new graphics utilities for the Apple I. * Anew brush mode lets you ‘pail with vartous size brushes in any of 108 colors, allowing unbelievably intricate shading, and tating Appie graphics out of (he “coloring Book™ ey : Magnification of pictures by factors | BE bw or four give you direct access: _ fo point-by point editing, Picture packing routines: reduce sciece Ato 10 pictures in RAM. a bio SOononedisk Extra tricks allow oe reverses, picture flips, micor images, snd = partial screen movement outs the Shite OF opposite screen SF _ As with all of our graphics products, documentation tells you how 10 use: ao in aoe — 2 _ Soteén tage From Special Effects from ~pensuin& software (Bormetty Co-op Software) makers of the “The Complete Graphics System” -Hi-Res Drawing, Hi-Res Character Generator, Shape Builder, and 3-D Graphics. Box 432, West Chicago, IL 60185 (B12)231-0912 NOW AVAILABLE: “The Complete Graphics System-Tablet Version’ $119.95 Appie His a trademark of Apple Computer, Ine live! alphaSyntauri" Live music on your Apple* computer? Yes! the alphaSyntauri™ a hands-on digital musical instrument, the first truly soft instrument, puts you in command... Play from 3 to 15 voices at once. control dynamics. see what you're playing in full color. record and save over 3,000 notes in a single session. playback at any speed. create and preset your own custom sounds and instruments with envelope and waveform control. change instruments and keys dynamically, and more... Tell me more! name address state zip phone(. ) demo record (lam enclosing $2.00) Syntauri corp., Dept. i 3506 Waverley Street Palo Alto, CA 94306 Contact Syntauri for your local Syntauri/Apple dealer. Educators contact us for liter- ature on Computer Assisted Instruction in music. * trademark of Apple Computer Inc. @® SOETALK NOVEMBER 1981 ninety-day ones, especially on software. After all, would you buy a system from someone who says, ‘‘Put your accounts receivable in the capable hands of our computer (software sold as is)'’? Philip Tubb, ALF Products, Denver, CO Softalk, the Matchmaker I am writing in reference to an article you published a year ago concerning Ap- ples and the handicapped. At the time, you wrote, ‘There seems no appropriate way to end this story.'' I thought you might be interested in its continuation, which has come to involve me. The emergence of personal com- puters has caught several people unpre- pared for this new technology. They are scared of computers, puzzled, uneasy. People in the computer field are still of- ten viewed as unfeeling robots working with devilish machines bent on lousing up that next phone bill or magazine sub- scription. Friends of mine still insist that computers ‘‘will never catch on.’’ I my- self used to hate computers. The story of how I became involved with the Apple began with that article in your magazine, and it’s another human interest story that might show people that the world of computers is not ro- botic, insensitive, or dull. In fact, it can be the backdrop for romance. In October 1980, Softalk published an article titled “Apples and the Handi- capped.”’ One of the persons featured in this article was David McFarling of Lin- coln, Nebraska, a quadraplegic who owns Small Business Computer Sys- tems, an accounting software firm. At the time the article appeared, I had just been hired by Dave to write promo- tional material and to give nonprogram- mer advice on his software. I took the job because I was unemployed and nearly penniless. For a while, there were a lot of doubts as to whether things would work out, and I began thinking of looking for another job. Then I read your article. The description of his computer sys- tem went right over my head (what's a serial interface?), but Dave's stubborn determination to conquer his handicap impressed me. His spirit was captured by the author, and one of the quotes [quot- ing McFarling] stuck in my mind: “Nothing, absolutely nothing, is tm- possible. True, there are some things the world is not yet ready for—or not yet will- ing to accept. When the chips are down, the difference between the possible and the impossible is the true measure of a man’s ability." “Nothing is impossible." I could learn about computers and be successful at my new job. I stayed on, and what happened later went beyond my expectations. T'm now handling the advertising in addition to being a technical writer. Not only do I now know the difference be- tween serial and parallel interfaces, but I'm learning to program on the Apple IL Plus. The business is growing; it's moved out of the living room into a new addition built onto the house. Dave is still work- ing hard and is now into Pascal. The best part of the story I've saved for last. Dave and I were married Au- gust 15. He was concerned at first that I wouldn't be interested in computers and would be a ‘‘computer widow."’ But when I started staying up until 2:00 a.m. work- ing on the computer and taking trade journals to bed with me, he knew we had similar interests. I'd like to thank Softalk for its role in the romance. Dave was too modest then to tell me his accomplishments. I had to read about them in a magazine. Your article impressed me and gave me the determination to stick with a job I was unsure of, and I'm so glad I did. The other night, I was working with one Apple, Dave on the other. Pausing for a moment, I asked, ‘Is this what our marriage is going to be like?’’ He replied that we could always send messages to each other via computer. But the mes- sage was already in his eyes: we may have a few bugs to work out, but this is one marriage programmed for happi- ness. Diane Walkowiak, Lincoln, NE Seeking New Beginnings In response to a letter about Beginners’ Corner, in which Tom Burt wrote in and said it was harmful to open up the disk drive door when the ‘‘in use"’ light is on: Well, the only real time it is dangerous to open the drive is when a write is in progress. During a read, the computer just picks up information. If you typed in for the computer to load a program and you realized that you have the wrong disk in the drive, it would not hurt to open the door and change disks in the middle of operation. I would have to agree with Tom that Beginners’ Corner does not give much in- formation. If it told us secrets about the Apple, like how to get other colors, short programs to help make shapes, how to make INT functions available in FP and vice versa, it would be better. Chris Rys, La Jolla, CA Scrambled or Sunny-Side-Up? In view of the space-age program that is conquering the computer owners of this country, Space Eggs, I would like to give this brief point. The biggest disappointment in play- ing the game is not, ridiculous as it is, the last fuzz ball sliding across the bottom of your screen to wipe out all hope of beat- ing your high score, or being destroyed by a meandering spider in the screen fol- lowing the successful navigation of the fuzz-ball field. The biggest disappoint- ment, in my humble opinion, is finally re- docking the first and second stages of your rocket, only to be blown up in the QUALITY DISK SOFTWARE BACKED BY ON-GOING APPLICATIONS SUPPORT HOME FINANCE PAK I: Entire Series $49.95 @ @ CHECK REGISTER AND BUOGET: This comprehensive CHECKING ACCOUNT MANAGEMENT SYSTEM not only keeps complete records, it also gives you the analysis and control tools you need to actively manage your account The system provides routines for BUOGETING INCOME AND EXPENSE, AUTO- MATIC CHECK SEARCH, and BANK STATEMENT RECONCILING. CRT or printer reports are produced for ACTUAL EXPENSE vs BUDGET, CHECK SEARCH OISPLAY RECONCILIATION REPORT and CHECK REGISTER DISPLAY by month Check entry is prompted by user-defined menus of standard purposes and recipient codes, speeding data entry and reducing disk storage and retrieval time Six fields of data are stored for each check amount, check no, date, purpose. recipient and TAX OEDUCTIBLE REMINOER, CHECK SEARCH routines allow searching on any of these data fields Upto 100 Oe PUES 2 Ss C2 GB ere oe oh no ee a SAVINGS: Account management system for up to 20 separate ae accounts Organizes, files and displays deposits, withdrawals andinterest PAUed MIRGAEH BCCHINE sn seas a clea seme ect ner wale wee 8 $1495 CREOITCARD: Get Control of your credit cards with this program Organizes stores and displays purchases, payments and service charges for up to 20, Separate cards or bank loans : 14.95 UNIVERSAL COMPUTING MACHINE: $49.95 @ A.user programmable computing system structured around a 50 row x 50 column table User defines row and column names and equations forming a unique computing machine. Table elements can be multiplied, divided, subtracted ar added to any other element Hundreds of unique computing machines can be defined, used, stored, and recalled, for later use. Excellent for sales forecasts, budgets. inventory lists, income statements, production planning, project cost estimates-in short for any planning, analysis or reporting problem that can by solved with a table $29.95 @ COLOR CALENDAR: Got a busy calendar? Organize it with Color Calendar. Whether it's, birthdays, appointments, business meetings or a regular office schedule, this program is the perfect way to schedule your activities The calendar display 1s a beautiful HI-RES color graphics calendar of the selected month with each scheduled day highlighted in color Using the daily schedule, you can review any day of the month and schedule an event or activity in any one of 20 time slots from 800 AM. to 530P.M BUSINESS SOFTWARE: Entire Series $159.95 @ © MICROACCOUNTANT: The ideal accounting system for small businesses. Based on classic T-accounts and double-entry booking. this efficient program provides ajournal for recording posting and reviewing up to 1,000 transactions per month to any one af 300 accounts. The program produces CRT and printer reports covering TRANSACTION JOURNAL BALANCE SHEET ACCOUNT LEOGERS INCOME ANO EXPENSE STATEMENT Includes a short primer on Financial Accounting. (48K) ....... $49.95, UNIVERSAL BUSINESS MACHINE: This program is designed to SIMPLIFY and SAVE TIME for the serious businessman who must periodically Analyze, Plan and Estimate. The program was created using our Universal Computing Machine and it 1s programmed to provide the following planning and forecasting tools. CASH FLOW ANALYSIS SALES FORECASTER PROFORMA PROFIT & LOSS SOURCE ANO USE OF FUNOS PROFORMA BALANCE SHEET JOB COST ESTIMATOR INVENTORY ANALYSIS REAL ESTATE INVESTMENT Price, including a copy of the Universal Computing Machine .... $8995 BUSINESS CHECK REGISTER AND BUDGET: Our Check Register and Budget Programs expanded to include up to 50 budgetable items and up to 400 checks per month Includes bank statement reconciling and automatic aoler kisah (ARQ p ia leet tse aleravareh cM on veces econ, 5 $49.95, ELECTRONICS SERIES VOL! & Il: Entire Series $259.95 LOGIC SIMULATOR: SAVE TIME ANO MONEY. Simulate your digital logic circuits before you build them GMOS, TTL, or whatever, if it's digital logic, this program can handle it. The program is an interactive, menu driven, full-fledged logic simulator capable of simulating the bit-time response of a logic network to user-specified input patterns. It will handle up to 1000 gates, including NANDS, NORS, INVERTERS, FLIP-FLOPS, SHIFT REGISTERS, COUNTERS and user-defined MACROS. up to 40 user-defined random, or binary input patterns Accepts network descriptions from keyboard or from \__ LOGIC DESIGNER for simutation ....seerseeeess $159.95 LOGIC OESIGNER: Interactive HI-RES graphics program for designing digital logic systems. Draw directly on the screen up to 10 different gate types, including NAND, NOR, INVERTER, EX-OR T-FLOP, JK-FLOP, 0-FLOP, RS-FLOP, 4BIT COUNTER and N-BIT SHIFT REGISTER, User interconnects gates using lire graphics commands. Network descriptions for LOBIC SIMULATOR generated simultaneously with the CRT diagram being drawn ........ $159.95, MANUAL AND DEMO OISK: Instruction Manual and demo disk illustrating capabihties of both program (8) ......0s.eeeeseee 82995 @)() ELECTRONIC SERIES VOL Ill & IV: Entire Series $259.95 CIRCUIT SIMULATOR: Tired of trial & error circuit design? Simulate & debug your designs before you build them! With CIRCUIT SIMULATOR you build a model of your circuit using RESISTORS, CAPACITORS. INOUCTORS. TRANSISTORS, DIOUES. VOLTAGE and CURRENT SOURCES and simulate the waveform response to inputs such as PULSES, SINUSOIOS, SAWTOOTHS, etc _ all fully programmable The output is displayed as an OSCILLOSCOPESTYLE PLOT of the selected waveforms (Apple only) or as a printed table of voltage vs time Handles up to 200 notes and up to 20 sources. Requires 48 RAM... .... 815995 @) (T) CIRCUIT DESIGNER: Interactive HI-RES graphics program for designing electronic circuits Draw directly on the screen up to 10 different component types, including those referenced above Components interconnect list for CIRCUIT SIMULATOR generated automatically. Requires ........... $159.95 MATHEMATICS SERIES: Entire Series $49.95 STATISTICAL ANALYSIS |: This menu driven program performs LINEAR REGRESSION analysis, determines the mean, standard deviation and plots the frequency distribution of user-supplied data sets. Printer, Disk. 1/0 routines: 319.95, NUMERICAL ANALYSIS: HI-RES 2-Dimensional plot of any function Automatic scaling At your option, the program will plot the function, plot the INTEGRAL. plot the OERIVATIVE, determine the ROOTS, MAXIMA, MINIMA, INTEGRAL VALUE 19.95 MATRIX: A general purpose, menu driven program for determining the INVERSE and DETERMINANT of any matrix, as well as the SOLUTION to any set of SIMULTANEOUS LINEAR EQUATIONS. 2.0.0... ec eceseue $19.95 3-0 SURFACE PLOTTER: Explore the ELEGANCE and BEAUTY of MATHEMATICS by creating HI-RES PLOTS of 3-dimensional surfaces from any 3-variable equation. Disk save and recall routines for plots. Menu driven to vary surface parameters. Hidden line or transparent plotting ....... $19.95 ACTION ADVENTURE GAMES: _ Entire Series $29.95 @ REO BARON: Can you outfly the REO BARON? This fast action game simulates a machine-gun DOGFIGHT between your WORLD WAR | BI-PLANE and the baron's. You can LOOP, OVE, BANK or CLIMB-and so can the BARON. In HI-RES. graphics plus sound... BATTLE OF MIQWAY: You are in command of the U.S. WORNETS: OIve- BOMBER squadron. Your targets are the Aircraft carriers, Akagi, Soryu and Kaga You must fly your way through ZEROS and AA FIRE to make your DIVE-BOMB run. In HI-RES graphics plus sound $14.95 SUB ATTACKcIts April 1943 The enemy convoy is headed for the CONTROL SEA. Your sub, the MORAY, has just sighted the CARRIERS and BATTLESHIPS’ Easy pickings. But watch out for the DESTROYERS - they're fast and deadly. In HI-RES graphics plus sound .. .. = $1495 FREE CATALOG-All programs are supplied on disk and run on Applell w/Disk & Applesoft ROM Card & TRS-80 Level Il and require 32K RAM unless otherwise noted Detailed instructions included. Orders shipped within 5 days. Card users include card number. Add $1.50 postage and handling with each order. California residents add 6!s% sales tax Foreign orders add $5.00 postage and handling SPECTRUM SOFTWARE 142 Carlow, P.O. Box 2084 Sunnyvale, CA 94087 FOR PHONE ORDERS: (408) 738-4387 == DEALER INQUIRIES INVITED. BEoeSR 20 first few moments of the game thereaf- ter. That is my opinion. Nasir, wherever you are ... that is one very mean and tricky game! Don Howe, Scotia, NY Adventurer’s Lot Is a Savage One The vast volume of software for the Ap- ple II has created a problem; even with ads and reviews, it is hard for the pro-. spective user to judge before he buys it whether a program will be enjoyable. Softalk reviewed briefly Scott Adams's Adventure #10: Savage Island, Part 1. I tried to play it for almost two months but finally had to give up and re- turn the program to the computer store. It may be labelled ‘‘for experienced ad- venturers,”’ but even this kind of person would be driven crazy with frustration. The trouble lies in the random factors that determine the occurrence of fatal in- cidents (bear eats the person, storm car- ries him out to sea). Every time I was about to overcome these two obstacles and find out finally what fired the can- non on the atoll, the sun set on me and “wait” never brought the dawn. I finally had to give up for good, even with ex- plicit hints from other players. If I was able to find the random fac- tor generator and disable it by replacing the random timing with fixed values so I would have a fighting chance, I would @ TSOFIALK NOVEMBER 1981 have continued. But with the bear, the storm, and the sun setting so I could not proceed, I was never given that chance. I advise anybody who has not pur- chased Adventure #10 not to buy it but to save his money for something else. Any- body who has bought it should return it to the store. It's far too unreasonable and frustrating (it will not save a game while the hurricane is raging, in fact). I've got- ten all but one point in the Microsoft Ad- venture but am unable to get anywhere in Savage Island. Unless it is tamed a bit by disabling the random generator, I am afraid it deserves a negative review. Thope that this letter will prevent a lot of people who are considering buying it from wasting their money, time, sanity, and health on this gantlet program. Paul R. Wilson, Bergenfield, NJ One man’s meat is another man’s hur- ricane. Magic Methods Revealed I read a letter from a John W. Butler of Apalachin, NY, in September 1981 issue of Softalk. John was asking about the use of Magic Window and the Epson MX-80 printer. Well, I have an Epson MX-80 printer that I am using with Magic Window, and I was having the same problem with the ESC control codes for the MX-80. I called Artsci, the vendor for Magic Window, on the keys to creativity Computer power A polyphonic synthesizer, a music tutor and a music transcriber all in one sophisticated package. Soundchaser:"Its a responsive music tool that allows computer technology to work with you and for you. Records and performs Soundchaser™ transforms an Apple II” into a dynamic polyphonic instrument. Record with the digital sequencer, play it back with a live overdub. Create unique, rich and natural sounds with up to six voices. Transcribes Notewriter “displays your melody and bass lines as you play. See your compositions on the CRT. Or toucha button and receive a printed score. Create, compose and arrange with one remarkable music tool. Teaches Musictutor™ transforms Soundchaser” into a challenging educational tool. The software includes programmed learning courses in ear training, music theory and harmony. Use it to develop skills and basic musicianship. Versatile and affordable ‘Soundchaser” is the only polyphonic synthe- sizer available that records, transcribes and teaches. It combines top quality hardware and software in a package that’s affordable. A six voice synthesizer and keyboard lists for $1350. Consider Soundchaser” Its a music tool that’ really worth your notes. PASSPORT DESIGNS wc 785 Main Steet, S E Contact your Half Moon Bay,CA 94019 (415) 726-0280, Soundehasi COMPUTER MUSIC SYSTEMS al dealer. “is registered trademark of Apple Computer, In. otewriter, Musietutor are registered trademarks of Passport Designs, Ine. this, and this is the solution to the prob- lem: Press control-B, then press the ESC key; this is then followed by the capital letter of control you want. For example, control-B, ESC, cap E will tell the MX-80 to go into emphasis mode. This can also be used with other MX- 80 controls; however, I have found out that sometimes you cannot put more than one control sequence on a line. I hope this solves John’s problem as well as those of other users of Magic Win- dow and the Epson MX-80 printer. Michael Gibson, Louisville, CO I would like to respond to a request for as- sistance from John Butler in his letter. Mr. Butler states he is having prob- lems interfacing his Magic Window word processor with an Epson MX-80 printer. There is a ‘Technical Notes’ document from Artsci covering this subject. The sequence Mr. Butler mentions is the one controlling emphasized printing. This sequence requires an ESC code in the text followed by an upper case EF (on) or F (off). Empbhasized printing works on a mini- mum of one line of text. The problem is the ESC code. It can’t be entered directly. The Magic Window uses the ESC key to control upper/lower case selection. But, by examining the ASCII code chart on page 7 of the Apple II Reference Manual, {you'll find that] the ESC key generates the hex code 9B. This value is what the printer expects. Back to the chart; a control-ESC also generates 9B. So the answer is to enter the ESC code into the text using the control code command (control-B) of Magic Window and the ESC key. The sequence becomes: Control-B, ESC, E—for on Control-B, ESC, F—for off The commas are for readability and must not be entered. I hope this helps Mr. Butler. I have been very happy with my Magic Window and the support documentation provided by Artsci. Roy Trahan, Fullerton, CA [To John Butler:] The problem you de- scribed . . . is probably caused by one of two conditions. The first is that any con- trol or escape characters entered must be in upper case. Since, however, you do not seem to be having problems with any control other than the emphasized print, it is more likely that your problem is in the limitation on the Epson emphasized print mode. Any escape-E found in a line will cause the entire line to print in em- phasized mode. The second rule is that you must not use the escape-F command (which terminates the emphasized print mode) in the same line as the escape-E. If both escape-E and escape-F are found in the same line, the printer will ignore The Ultimate Fantasy Experience Wizardry—a revolutionary game for your APPLE Il com- puter. Never before has a game done so much, so well, so fast! Groups of up to 6 adventurers explore a deep and mysterious maze in search of loot and glory. Brawny fighters, frail mages, nimble thieves, all must cooperate to survive. Not only must you battle hordes of monsters, but you must also solve the secret riddles hidden in the mazes. Starting from the safety of the castle, you must map the 3D maze as you move through it, swiftly running down the corridors and smashing through doors! Sud- denly you encounter a group of monsters in their hideous lair! Leaping to the attack, swords swinging, your fighters wreak havoc amongst the monsters! Mages utter spells, causing destruction! Thieves skulk around in the corners, and priests attempt to bring the blessings of the gods upon your party! After the melee, there may be a chest to open, traps to evade, and loot to be divided! A partial list of Wizardry features includes—A 10 level maze—8 character classes—5 races—20 stored on disk— 3D maze display—complete castle—hundreds of monsters and magic items—monsters appear in mixed groups—50 castable spells, usuable by players, magic items and even monsters—44 page illustrated manual and much, much more all for $49.95 (N.Y. residents add sales tax). But don't take our word for it, Wizardry received reviews in the May issue of Creative Computing, the April issue of Popular Mechanics, page 38, and the August issue of Softalk magazine. At Leading Computer Stores Everywhere ; SOFTWARE, INC. Dept. F Sir-tech ) 6 Main Street / Ogdensburg, New York 13669 / (315) 393-6633 [Seiwa VISA Apple is the registered trademark of APPLE COMPUTER, INC. 22 the escape-E, the line in regular print. I have been using the Magic Window and Epson MX-80 with my Apple II and have found them very compatible and satisfactory. Good luck with your problem. Martin Tiersky, Lincolnwood, IL [printing] From Soup to Nuts—or, from Wagner to Robots Excellent! The September issue reaches new heights; and all for free, too. It’s hard to believe. Softalk is by far the best Apple magazine available today. A cou- ple of comments: 1. Ihope Wagner’s Assembly Lines is printed in book form. It is clearly excel- lent. 2. I’m becoming confused about the new memory expansion boards now available, including the recent 64K board. I wonder if you would consider re- viewing them in a future issue. Specific- ally, I would like to know how I can get the maximum amount of memory avail- able to me for programming. I already have a language card and understand I might be able to use a second 16K board. on which to locate DOS, but I don’t quite get it. Can you explain? 3. The article on the new compilers was excellent; however, I still have one question: can an Integer ROM machine make use of these programs? Some of @ YOFTALY NOVEMBER 1981 the ads say ‘‘Applesoft ROM or equiva- lent.” Does this phrase mean Applesoft in the language card is okay? 4, I just received my Robot poster. Thank you. Unfortunately, it arrived a bit wrinkled, and one of the mailing tube covers was gone. I was really hoping to frame it. Would it be too much trouble to send me another? I'd be glad to pay ex- penses. Michael Schuyler, Kingston, WA 1. Look for Roger Wagner’s Every- one’s Guide to Assembly Language in book form around Thanksgiving. Init are the first year’s columns, revised and ex- panded, and some new material. 2, No sooner said than done. See page 84. 3. RAM Applesoft loaded into the lan- guage card or into a RAM card is indeed the equivalent of ROM Applesoft. 4. As we said in letters to all pur- chasers, if your poster arrived dam- aged, simply let us know, and you'll re- ceive another. We added an outer box over the double tube packing as soon as we heard some posters hadn’t made it through the mails unscathed, A Letter to On-Line Before I begin, I ask you to turn to page 68 of the September issue of Softalk. It is the ad at the bottom of the page that brings me to write this letter. VISICALC* FORMATTING AIDS OONOWAWN— WHAT YOU CAN DO WITH VISI-CAIOS: Print or display VisiCalc models with variable width columns! Print a column 1 or 2 characters wide! Simulate a split screen on you printer! Split wide label columns into 2 or more narrower columns! Print or display formulas. labels. etc. arranged in columns! And More! VISA-CAIDS 2.1 is menu-driven throughout and easy to use. For added flexibility and improved reports buy VISA-CAIDS today! Only 34.95! (through December 31. 1981.) Requires less memory than VisaCalc. Available in OOS 3.2 and 3.3 Applesoft. 1 or 2 disc drives. Ask your dealerororder directly from Data Security Concepts, P.0. Box 31044. Des Peres. MO 63131. (314) 965-5044. "VisiCalc is a trademark of Personal Software, inc. I had hoped the computer industry could remain immune to the current wave of sex in advertising. You have proven that I was, indeed, naive. I can- not understand why you feel you must sell your software—‘‘for adults only’’ or not—by using pictures of naked women. You could at least have the decency to pose your models lower in the hot tub, so as not to turn Softalk—an otherwise fine publication—into cheesecake. Softalk is read by many Apple owners, and, while I myself am single, there are many owners with children who read their issue of the magazine. Finding an ad like yours in the magazine must certainly put these parents off. It is bad enough that their children’s televi- sion viewing hours are riddled with sexual themes and suggestions. Now a child can’t even attempt to work with a computer—an essentially sexless tool— without being besieged with these un- necessary ads. I, for one, hope you will take a close look at your advertising strategy for this product—which, in my opinion, is as use- less and unnecessary as its ad—and think about what you are doing to the com- puter industry. I feel you are lowering it to the gutter level of all the other indus- tries that have used sex in advertising for so many years. Richard Gillett, Manhattan, KS Vacuous Sex Symbol Misrepresents Women Softalk has become a valuable resource in the classroom along with Creative Computing and others in my computer literacy class. Page 70 is not in good taste with your usual informative magazine. Women will never get out of the bed- room if this type of advertising is con- tinued. We've come a long way, and it’s up to us to complain when we are put down this way. Mary Miller Smith, Doraville, GA A Plea for Working Disks Recently, I spent about $600 on Hayes Micromodem, Visiterm, and Source for my eighteen-month-old Apple. Although I've never had problems with my disk drives, neither software package would load, and it took several weeks and numerous trips to the local Apple store before I was up and running. It does not seem fair to me, to the store, or to Apple Inc. to market disks that are so margin- ally readable in the name of being copy- proof. This was not cheap software, and so I have a right to expect quality! Also, the most important single ex- pectation of the software was that it switch incoming material to the printer (Silentype) when I want hard copy of names, addresses, and significant data. Some day I may want to transmit or re- ceive files, but first of all I want a com- munications capability. Arthur Radcliffe, Ann Arbor, MI = | THE GREAT SIMPLIFIER: end Edition Edition ~~ Encyclopedia of the BASIC Computer Language by David A. Lien fr. only book that simplifies the BASIC language by explaining its many dialects is now even better! We've added 240 BASIC words from the world’s latest computers, fora new total of nearly 500 words detailed in a concise easy-to-read manner. The 480-page 2nd Edition BASIC Handbook tells you everything you need to know about today’s BASIC language. It explains ai/ significant Statements, Functions, Operators and Commands, so you can put them to work instantly! If there’s an alternate way to write a program using other BASIC words, the Handbook shows you how. If a program needs a Function your computer doesn’t have, the Handbook generally has a subroutine which does the same thing. And it’s all alphabetized and indexed for fast access! The big new 2nd Edition helps you convert those “‘strange”’ programs found in magazines and professional journals to RUN on your computer. Extra sections describe many specialty BASICs, including Atari, Sinclair, Tektronix, TRS/Color, plus Disk BASIC. For students, businessmen, hobbyists, and pros — anyone who works with BASIC, the updated Handbook is indispensable. Order your Second Edition today! It’s the missing link between you and more computer power! oe 2 ee 2 ee ee ee ee 2 ee ee ee Yes! Give Me More BASIC Power! Please send - copies of THE BASIC HANDBOOK 2nd Edition. My check for $19.95 each and $1.65 P&H is enclosed. (Californians add 6% tax.) © Charge it to my MasterCard or Visa (circle one) Acct. No. Exp. Date Name Address - City. State. —— Zip — Signature Mail to: CompuSott® | Publishing, 1050-E Pioneer Way, Dept. D El Cajon, CA 92020 Or Call: (714) 588-0996 to order now! MEROSOFT Last month we left off our continuing series on Basic-80 after defining those of its commands that do not exist in either of the Apple Basics. This month we'll begin a discussion of Basic-80’s disk file commands and the ways in which CP/M handles data files differently from Apple DOS. Among other things, we'll examine in depth the logical and physical structures of text files, since an understanding of these matters will help you optimize your files for speed and disk space. We'll deal with the primitive storage of data on the disk only to the degree necessary to explain differences be- tween CP/M and DOS. For those of you who might wish a closer examination of the more esoteric aspects of disk file handling, we may take up that topic in a future column. We should point out that, while anything stored on a disk is in fact a disk file, we will be using that term interchangeably with data file and text file; all three of these terms may be taken to mean data files created from Basic. Under both CP/M and DOS, there are two types of files: se- quential access and random access; the names are usually shortened to sequential and random. As the words indicate, the general difference between the two types lies in the way in- formation is accessed by the operating system when it reads from and writes to the file. This, in turn, is dependent on the way data is stored within the file. The way the data is stored defines the file's format or struc- ture. Before proceeding, we should define a couple of terms so we'll be on common ground. The term byte refers to a unit of information manipulated and stored by the computer. In the case of data files, where more often than not data is stored in the form of ASCII characters, the byte is the smallest unit of the file and equival- ent to one ASCII character. Therefore, the word hello in a text file would be made up of five bytes. The term data element means a logical unit of data defined by you, the programmer. It may be composed of one byte or many bytes of physical data, but it’s always a complete, logical unit to you. Stated simplistically, sequential files store data elements one byte after another, with the elements packed together and separated only by a delimiting character—usually a carriage return. No intervening spaces exist—except those you pro- vide—so the file is a stream of bytes occurring in the exact order in which your program wrote them. Random files, on the other hand, can be thought of as a number of boxes of identical size. These boxes are called rec- ords: their size is determined by you when you create the file and must be specified each time the file is accessed. Each record may contain one or a number of data elements, at your discretion, but the smallest unit of the file that Basic can rec- ognize is the record. The record supplies you with a fixed number of bytes of space, and what you do with them is totally up to you. The only thing Basic will do is add a carriage return at the end of your data in Apple DOS, or fill up any unused space in the record with the ASCII code for space in Basic-80. At this point, the reason for the names sequential and random becomes obvious. Because all the data is in sequential files is packed together, Basic must effectively examine every byte in order until it finds the byte or bytes you want to access. On the other hand, since random files are made up of records of identical size, Basic knows—through calculation—how far into a file to go to reach a specific numbered record. It can, there- fore, access any given record directly without having to read all the previous records. Both types of files have their advantages and disadvant- ages. Random access files are generally longer, since they contain the wasted area that Basic padded with spaces; how- ever, data access in a random file is generally faster, since Basic can go immediately to the record being sought. For the same reasons, sequential files, while more efficient users of space, are generally slower to access. Because there are no inherent limits on lengths of data ele- ments in sequential files, while there are in random, the two file types differ in the amount of planning they require of a pro- grammer. Ina sequential file, Basic needs no information con- cerning the length of the data element since it knows it has the entire element as soon as it encounters the delimiter. There- fore, in this kind of file, you can intermix different types and sizes of data with little advance planning. The random file situation is different. Since the operating system has to be told by you, the programmer, how many bytes constitute a record, you will need to do some thinking about the maximum sizes of data elements and the overall structure of the file—before you write a single byte of data. The fact that sequential files require less forethought, how- ever, does not make them better than random files in all situ- ations. In fact, many programmers are led by this apparent simplicity to expend unnecessary effort trying to get a sequential file to do an effective job on their data, when the type of data is really better suited to a random file structure. Now that we're reasonably sure we're all talking about the same things when we talk about the types of data files, let’s take a look at the similarities and differences in the ways text files are handled under Basic-80 and Apple's Basics. Apple text files, for all intents and purposes, have the same characterist- ics whether they are created by Applesoft or Integer Basic, so we will treat files created by both of these languages as features of Apple DOS. In Apple DOS, sequential file manipulation is done in the tra- ditional sense, as described above. All data is stored as ASCII representations of individual characters, with each data ele- ment separated by a single carriage return as a delimiter, In fact, the only difference between the format of Basic-80 text files and those made by Apple DOS is the fact that Basic-80 uses a carriage return and a line feed together as a delimiting pair. Although there are differences in command syntax—which we will discuss shortly—the logical structure of sequential files under both systems is the same: data element, delimiter(s), data element, delimiter(s), and so on. Samples of the actual disk images for the same sequence of data elements in DOS and CP/M files are shown in figure 1. With regard to random access files, however, there are major differences in the logical structure itself. Before we at- tack these differences, let’s take a look at the physical struc- ture of both Apple DOS files and CP/M files. The terms we'll THE DAILY DOUBLE THE DATA FACTORY. | = EASY-TO-USE Get ahead and stay there. The Invoice Factory and Data Factory are a win- ning combination for any office. The Data Factory keeps information or- ganized and accessible. Find the in- formation you need in seconds. Ac- cording to a recent study, after only half an hour with the manual, a new operator (who has never used a com- puter!), can begin to input data. No other data base manager is this easy to understand and use. LARGE ENTRY CAPABILITY You can use the total capability of the Apple computer. Up to 88 categories (fields) for information storage can be selected and each one may contain as many as 239 characters. These limits are larger than any comparable pro- duct on the market. FLEXIBILITY You can change your mind. Append additional fields for information stor- age at any time. Transfer any part of your records to formanewfile. Addor delete characters in a field when more or less space is needed. No need to re-enter any data again. Even if you have a damaged record from Power surges or other circum- stances, you can reconstruct the usa- ble data. The program is the most flexible one currently available for the Apple micro computer — This is where its power lies. NEW RECEIVABLE SYSTEM Use the account data from The Data Factory and transfer it to The Invoice Factory to print invoices, statements, receivable reports, or sales analyses of products quickly, accurately, and effortlessly. With only an account number entry, all pertinent informa- tion on an account is automatically before you — shipping address, terms, contact, etc. Choose the pro- duct code and enter the amount or- dered. Automatically the numbers are extended, tax and handling charges computed and UPS freight rates to- taled. An audit trail and product sales analysis is available from the original order entry. You always know how much outstanding money you don't have, how current sales compare to last months, and the total of every- thing a customer has purchased within any given time period with this complete accounts receivable sys- tem. ‘Apps 2 vademarko! Apple Computes. Ine micro is (le 7 a systems that work JE CONSUMER CONCERN You can bet on Micro Lab. Itisa name that you can rely on. Our products have been sold to thousands of cor- Porations. Our Extended Warranty, back-up program copies, and cus- tomer service policies are the stan- dard in the small computer industry. When you decide to buy a Micro Lab product, you can be assured that our system will work. EFFICIENCY PAYS For a minimum investment in this in- expensive computer system, your en- tire office will function smoothly and efficiently. By using The Data Factory and The Invoice Factory with an Apple computer, the time saved in data re- trieval and sales analyses will soon pay for the entire cost of the system. Large corporations need not tie up their main computer with specialized office procedures and record keeping — you can place one computer in each department, or tie a branch of- fice into your system with a modem. The Data Factory retails for $150 and The Invoice Factory is $200. For further information about Micro Lab Products, contact us directly or go to your local Apple computer dealer for a demonstration. You can't afford to be without our products. 2310 Skokie Valley Road e Highland Park, IL 60035 @ 312—433-7550 26 @ SOETALK NOVEMBER 1981 EXAMPLE: For the three data elements APPLE, PEAR, and the number —27, the disk images appear as follows: APPLE DOS; A Pp PL E[CR)P E€ A R [CR] - 2 7 C1 DO DO CC C5 8D DO C5 Cl D2 8D AD B2 87 BASIC—80 A PP LE [CRI[LF] PE A R [CR[LF] - 2 7 41 50 50 4C 45 OD OA 50 45 41 52 OD OA 2D 32 37 Figure 1. NOTE: All numbers above are in hexadecimal, and the differ- ences in the values shown are a result of the Apple’s use of some- thing called negative ASCII in which all values are exactly 128 decimal, (80 hex), higher than normal. See your Apple Refer- ence Manual for a list of these codes. need are: track, sector, block, extent, allocated, unallocated, track/sector list, and directory. Track refers to a ringlike area on the disk where data is written by the disk drive. All Apple Disk II drives provide for thirty-five such circular areas, each slightly smaller than the one outside it. They are numbered 0 through 34, from outer- most to innermost. Each track is further subdivided into a number of equal-size sections called sectors. On the Apple, the number of sectors per track is either thirteen or sixteen; our discussion is applicable to either case. Obviously, the higher the track number and the smaller the ring comprising the track, the less physical distance is repre- sented by a sector. In the Apple, however, whether Apple DOS or CP/M is used, each sector consists of exactly 256 bytes, with those sectors nearer the center compressing more bytes per unit of distance. This 256-byte sector is the smallest logical and physical unit that can be manipulated by Apple DOS and is, in fact, the only unit it deals with. CP/M, however—because it needs to be port- able between machines that may range from 128-byte sectors to 2,048-byte sectors—has adopted a 128-byte logical sector. GUESS wear, ALDoo ! WORD PRocessiWE SorrwAKE Fee APPLE TASCAL | FROM TNTELUCENT SYSTEMS, OF Course/ ‘onl , MS.SPELLER II UPDATED VERSION SPELLING CORRECTION & PROOFREADING FINDS AND SUBSTITUTES CORRECT SPELLINGS 60,000 word main dictionary- CREATES personal dictionaries - BUILDS BADSPELLINGS DICTIONARY from user errors- Automatic and user- interactive modes FOR MULTI-DRIVE SYSTEMS SMALLER DICTIONARY AVAILABLE FOR SINGLE DRIVE SYSTEMS PRICE: $75.00 SPECIFY NUMBER OF DISK DRIVES NEW PRODUCT ! QTEXT — provides professional quality word processing with APPLE PASCAL EDITOR FEATURES INCLUDE : MAILING LIST CAPABILITY, HEADER AND FOOTER LINES ,COPY STANDARD PARAGRAPHS IN DOCUMENTS, PROPORTIONAL SPACING FOR DIABLO AND QUME PRINTERS, USES FORMAT FILES ANO OVER 40 EMBEDDED TEXT COMMANDS FOR CONTROL, AUTO PAGE & CHAPTER NUMBERING, USER FRIENDLY PROMPTING, COMPLETE DOCUMENTATION, RIGHT, LEFT & CENTER JUSTIFICATION & MORE DEALER INQUIRIES WELCOMED 1-year software warranty SYSTEM REQUIREMENTS : LANGUAGE 5 YSTEM plus $2.50 shipping 722 South 24th Streets PRICE $100 Intelligent Computer Systems Corporation Va, residents add 4% sales tax Arlington, Va, 22202+ (703) 684-7389 When CP/M is used on the Apple, the physical sector—the smallest unit the drive can handle—is still 256 bytes, but CP/M is kept ignorant of this fact by translations that take place in the BIOS. The important point to remember here is that, while Apple DOS recognizes only 256-byte structures, both logically and physically, CP/M deals with 128-byte logical sectors and 256-byte physical sectors. The next larger logical unit that CP/M recognizes is known as a block. The term group is also used to describe this unit, but we'll use block exclusively, to avoid confusion. Since Apple DOS has no equivalent unit, CP/M is free to define the term without fear of conflict; hence, a block in Apple CP/M is always 1K bytes. CP/M numbers blocks from 0 to 131, starting at track 2, sectors 0 through 3, and ending at track 34, sectors 12 through 15. The largest logical unit of disk storage used by CP/M is the extent. Files longer than 16K are divided into logical extents of sixteen blocks each. These extents are numbered from 0 through the amount needed to complete the file. The concept of sectors, blocks, and extents as three graduated units of disk file structure will be important as we proceed, so be sure you have a firm grasp of these terms. Now that we have some units to deal with, we can talk about their allocation. Both CP/M and Apple DOS set aside certain space on the disk whenever a file is created or added to. This process is known as file allocation. It can be seen, then, that any disk in use is made up of allocated and unallocated space, and that both CP/M and Apple DOS must deal in cer- tain minimum units of allocation. In DOS the unit of allocation is again the 256-byte sector, while in CP/M the minimum unit of allocation is the 1K block. Obviously, both systems need a way to keep track of the al- located and unallocated space, and both do it by using special types of files called directories. Directories are simply a col- lection of records—35 bytes each for Apple DOS, and 32 bytes each for CP/M. The directories contain information such as the file name, status (active or deleted), some type of list (CP/M), or pointer to a list (DOS), of storage units allocated to the file. In DOS the list pointed to by the directory entry for the file is called a track and sector list; in CP/M the list is called a block allocation table and is contained in the last sixteen bytes of the directory entry. By now some of this should be coming together for you. For example, in CP/M—since there are sixteen bytes available in the entry for listing block allocation—a maximum of sixteen blocks (16K of allocated space) can be listed. If more is re- quired, another directory entry (the second extent) is created, and sixteen more blocks can be listed. In DOS, the directory entry’s track and sector pointer indi- cates a specific sector where there is a list of two byte entries (track and sector) that make up a complete map of the file’s allocated space. Each sector can hold 122 such entries and, if necessary, a pointer to another sector where the track/sector list is continued. But do we really need to know all this to understand ran- dom file storage? Possibly not, for a superficial understand- ing, but we implied at the beginning that confusion about what went on below the surface was the cause of a lot of inefficiency in random file usage; and one of the most confusing aspects of random files is how Basic is able to add records between other records, without having previously allocated the space. Now it’s fairly obvious that if Basic had access to an imagi- nary 8.5 million-byte disk, and could use this disk to store a single file of 32,767 256-byte records, then it could allocate physical space for the entire file. In that case, it would be easy for it to calculate the track and sector to read and write when you asked for a par- ticular record from number 1 to number 32,767 (the range of ran- dom record numbers allowed by both systems). Our real disks, however, are of only 126,000 bytes total capacity, and although we cannot store all 32,767 records, we still require Basic to access any record number within that range. You need just one more piece of the puzzle to see how that’s done. The answer is that, while the system does not allocate a THE BEST 250 DOLLAR WORD PROCESSOR ON THE MARKET... SuperScribe || is the most powerful and easiest to use Word Processor available for your — Apple Il or I Plus computer. Besides leaping tall buildings in a single bound, it: si ¢ Gives true upper/lower case text on your screen with no additional hardware whatsoever. ° Works with documents larger than the amount of memory in-your Apple—transparently to you! ¢ Edit not only letters but also any text or binary file, or even basic programs! ° Automatically generates up to 4 separate indices for your document! ° Save typing time through a unique ability to designate specified keys as commonly used words, phrases or even commands! * ° Globally search for or replace character strings. ¢ SuperScribe Ii has a built-in instruction capa- bility such that if you forget how to use a command and the manual is not close by - you may simply ask SuperScribe I[. and it’s only 129.95 .. . ° Supports multiple disk drives! © Will support alternate character sets. e Supports the shift key modification if made to. 5 your Apple. e Lets you work with your text on a screen at a time basis—reducing typos and allowing you to see - your document as you edit it. ° : 3 © Works with any printer! © Proportional Spacing! : e Hyphenations made ui © Supports the language card or any 16K expansion Ram card to keep more of your document readily . available in memory. ‘ : © 70 column review—see your text formatted in 70 — character lines before you print. Again, without SUPEASCTIO“ by 3657S MUDGE RANCH RDAD CDARSEGDLD, CA 93614 209-683-6858 additional hardware! lh be IL 28 @ SOFTATE NOVEMBER 1981 space for the actual records, it does allocate space in the block allocation table and in the track/sector list for all those entries that might eventually exist physically. For example, in CP/M, when Basic is told to create a file and write record 1, it creates the directory entry in block 1 or 2 (reserved for the directory only), finds an unused block elsewhere on the disk, writes the record, and then enters the block number in the block alloca- tion table as the first entry. Later, when it's told to write rec- ord 82,767, it calculates the number of the extent where such a record would be found if it existed. It then looks for the extent and, if it cannot find it, creates it. Next, it finds another unused block, writes the record, and, finally, enters the block number in the block allocation table of that extent where it would appear if the extent were fully allocated. So storing record 32767, rather than costing 8 million bytes of allocated space, has cost an additional block and another thirty-two bytes in the directory. Apple DOS performs similarly, except that it also creates all the empty track/sector lists in between, which—for the ex- ample given—would cost 262 sectors of additional allocated space. By now you should already be aware of how proper planning of things like record number ranges—rather than just taking the easy way out by using people’s social security numbers, for example—can greatly increase your file storage efficiency. Now we'll look at the specific differences in the handling of data elements and the general command differences between Apple DOS and Basic-80. The only new terms we will need are buffer and field. The general definition for buffer is a space reserved in memory to store temporarily a series of bytes—either prior to, or follow- ing, an I/O operation. One example is the buffer used to store keyboard input on the Apple until you hit return. With regard to random files, the buffer is a space in mem- ory that stores the contents of the disk sector containing the record or part of a record you are working on. The smallest unit of data the Apple drive can move in or out of the buffer is the disk sector, so when you manipulate data elements in a sin- ©1981 Stoneware, inc. Apple Il 1s a registered trademark of Apple Computer gle record, you are actually altering only the contents of the buffer. The disk file is not updated until you either close it, read or write another record, or—in the case of large records—be- gin manipulating a part of the record that appears in a subse- quent sector. The buffer itself is divided into sections called fields. They may be defined implicitly by the system as a single data ele- ment, as in Apple DOS, or they may be under the complete control of the programmer, as in CP/M. They are a logical unit, however, and vary in size; therefore, they should not be con- sidered in the same way we consider fixed-size units like blocks and sectors. The concept of fields should become easier to understand as we discuss random files, but it’s important to remember they’re a logical construct that’s meaningful only to the buffer, not the disk file itself. While Apple DOS does do the primary job of allowing a programmer to access individual records randomly, it treats the record itself as a kind of sequential file. Your data ele- ments are written into the record one after another, separated by a carriage return as delimiter—just as they are in sequen- tial files. Also, as in sequential files, numeric data elements are stored as a series of characters rather than as actual numbers. Thus, when you enter data elements into a record for the first time, DOS sets up the length and position of the fields in the buffer according to the length and order of the elements you write. This information, however, is not stored in the file; con- sequently, when you go to update the file, unless you have rather exact knowledge of the contents of the record, it be- comes difficult to access a particular data element without ac- cessing sequentially all preceding ones. If you do have such knowledge, DOS gives you the option of using the POSITION command to index into the record a specific number of fields, as well as the B (for byte) parameter to in- dex in a specified number of bytes. Keeping track of this kind of information, however, may be an unreasonable amount of work. Further, since DOS random records are structured like HOT NEW GAME For the Apple Il! e SUPER GRAPHICS! e FAST ACTION! e TWO GAMES — 1 OR 2 PLAYERS! It's MAZEMAN against the Aliens. Guide MAZEMAN through the maze and rack up points by devouring the Power-Puffs. But watch out for the smiling Aliens, cause they're out to get you. Devour Aliens while they’re transparent and score bonus points! When two people play, second person controls two of the Aliens. And the Chase is on! EXTRA FUN! EXTRA CHALLENGE! Buffered keyboard makes changing directions easier and quicker! At your computer deale: Requires 48K. Disk $29.95. 50 Belvedere Strat, Son Rana, CA @400% (41S)484-6500 Synerg istic Software 5221 120th Ave SE Bellevue, Washington 98006, “Apple li and Appiesoft are trademarks of Apple Computer, Inc. and , in du \d ca: different each time you play. Plan your strategy, solve the puzzles, and survive the endless variety of hazards and foes to reap your rewards. Odyssey is an ever fresh mythic adventure. “Apple I1, DOS 3.2 or 3.3, 1/A — $30.00. 30 @ SOFTALK NOVEMBER 1981 ONMINI The “Everything” I/O Board for the Apple I & I+ OMNI 1s a multi-function input/output board for the Apple Il or I+ computer It provides, on a single board, most of the “missing” features needed to make the Apple a complete computer With OMNI your Apple can have paraiiel /O with handshaking + RS232 Level serial 1/O {software Griven) + 24 Hr Real Time Clock with Alarm + 2K EPROM with graphics, 1/O driver, and screen editor firmware + 256 Byte PROM supervisory firmware + Six 2K PROM/EPROM expansion sockets software selectable (one socket used for Eclectic firmware, 5 available for user) INPUT: + Generate full ASCII character set from keyboard + Optional shift key detection + User-definable “soft keys with screen legends + Integrated text line editor full cursor movement, insertion/ deletion modes + Key legend stickers included + Demonstration Diskette with pro- gramming examples and a Soft Character Editor OuTPUT: + Full 96 character ASCII display + Concurrent 64 user-definable “soft” characters + Optional character overstrike and EOR on background + Optional double-width color characters + Character rotation in 90° steps Never before have so many functions been available on a single board OMNI was designed with one major goal in mind, flexibility The OMNI system consists of some extremely simple but very sophisticated hardware, a large amount of powerful firmware (programs permanently residing in Read Only Memory chips), and an equally extensive amount of software (programs residing on diskette that are loaded into RAM as needed} In addition, OMNI comes with extensive documentation eECLeCcuiC CORPORATION To order TOLL FREE: 1-800-527-3135 or Order by Mail Below Eclectic Systems Corporation, P.O. Box 1166, Addison, TX 75001| Here's my order for OMNI at $268 plus $3 for shipping and handling (UPS surface, unless specified}, $5 overseas. My check is enclosed 0 Please charge my VISA __ Mastercard __ Account # Expires Name Address City/State Zip Signature sequential files—with no provision for setting fields larger than the data element itself—the field doesn’t allow for the case where a data element enlarges at a later time (dollar amounts in an accounting program, for example). If you want to pro- vide for this situation, you must pad the fields with spaces yourself when you first create the file, or resign yourself to re- writing the rest of the record each time you update a field. In contrast with Apple DOS, Basic-80 provides full control over field allocation, allowing the programmer to field the buf- fer any way he chooses, setting a field to enclose single or mul- tiple elements or even a partial element. This process is per- formed using distinct string variables to represent the fields, so that once buffer fielding has been done, all assigning and up- dating of elements—as well as all retrieving of elements—is accomplished by a simple reference to the variable used in the field statement. Data elements are placed in the buffer using the SET command either to left-justify (LSET) or right-justify (RSET) the data elements into the field; you control which end of the field will be padded with spaces. Also, Basic-80 stores numeric values in the file as special tokenized strings that, for a given precision and type of num- ber, are always the same length. The fact that the length of a numeric field remains constant for a given precision and nu- meric type reduces the amount of times it's necessary to extend or shift field positions as numbers enlarge and shrink. As a result, the programmer is given much more control over the individual file record than is possible under Apple DOS. To compare actual command forms between DOS and Basic-80, we must first point out that, unlike Applesoft and Integer, Basic-80 has specific disk file commands built in, elim- inating the need to precede disk commands with a control-D sequence. Also, since commands exist to set data into the buf- fer and display data currently in the buffer, it isn’t necessary to tell Basic-80 prior to accessing the buffer whether the opera- tion will be a read or a write. In sequential file activity, the mode (either input or output) is set in the OPEN command. Specific differences, then, are as follows: First, in sequential file activity, it's not possible in Basic-80 to output to an existing file, since Basic-80 will delete the file automatically before writing any data. To add data to a file, the file must be read in, and simultaneously written out, to a second file with the desired changes and additions. This pro- cedure differs from Apple DOS, which allows both input and output to an existing file. Even DOS, however, forbids data to be inserted into the middle of a sequential file. It's possible to overwrite existing data elements with new ones of exactly the same length, and the file can be extended beyond its current end-of-file mark, but any other write operation will destroy the integrity of the file. To open a file in Apple DOS thus requires only the state- ment PRINT “CONTROL-D OPEN FILENAME”, while in Basic-80 the mode of the file needs to be stated as well—as, for example, OPEN “I’’,1,‘FILENAME.DAT" for input or OPEN “O"",1,‘FILENAME.DAT" for output. You'll notice in these Basic-80 commands that a number follows the file mode desig- nator. This is the number of the buffer to be assigned to that file for all activity that follows. Specifying the buffer number allows later commands to omit the file name—for example, CLOSE 1. Writing to or reading from Apple DOS files requires subsequent statements of the form PRINT ‘“‘CONTROL-D WRITE FILENAME” or .. . READ FILENAME’’—followed by statements of the form PRINT ‘(this is your data]"’ or IN- PUT “(this is your data]"’ respectively, while Basic-80 requires only ‘PRINT #1, “[this is your data]" and INPUT 41, “‘[this is your data]’’. Since special print commands are used in Basic- 80 to write to the file, normal print statements can be inter- mixed with file writes. In DOS, on the other hand, any PRINT encountered after the ... WRITE FILENAME” command will cause a file write unless the file has first been closed. Finally, Basic-80 allows the writing of formatted numeric data to sequential files by means of the PRINT #X, USING [mask] command, which forces numbers to be written in the GOTO 33 NOVEMBER 1981 TOFTALKL@ 33 SOFICARD Symposium from page 30 form of the mask used with the statement. PRINT USING is not implemented in Applesoft or Integer. Specific functions also exist in Basic-80 to detect the end of the sequential file (EOF), the number of disk file sectors read and written since the file was opened (LOC), and the length of the file (LOF)