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ALSO PUBLISHED BY PEOPLE'S COMPUTER COMPANY: DR. DOBB's JOURNAL of COMPUTER Calisthenics (,
If you're tired of plugging canned programs Orthodontia into your computer, Dr. Dobb's Journal is the magazine for you! We publish software OUR READERS SA V: that will allow you to get "inside" your machine. You will be able to make it do " I received my introduction to your anything you want it to do. Dr. Oobb's remarkable journal and was as pleased as is a serious magazine for those people who a Lovecr.ft wizard coming upon a copy of really want to learn as much as they can the Necronomicon. Really. yours is the about their microcomputer. only real computer journal going. Dr. Dobb's is to the other "small systems" Recent issues have included: • An AII·CP/M periodicals as Scientific AmericlllJ i. to Issue, including an overview of CP/M-compatible Popular Mechanics." software, the history of CP/M, utilities, inter preters, etc .• Mathematical Typography by "Dr. Dobb'$ Journal is a truly impressive Donald Knuth • A Microprocessor-Assisted periodical unlike others I've react It Graphics System • Interfacing a Home Computer contains valuable and useful software. to a Large Scale System • Improvements to I look forward to its delivery every 8080 PILOT month." ....------.....------
Editors' Notes Staff May/June 1980 Volume 8. Issue 6 Seuling In Editor D~nnis Allison Contributing Take the mystery I cut it OU I of Ihe newspaper and lacked it Editors lbov~ my desk here II PCC-a comic urip, Bob Albrecht Shoe to be eXl ct. The patter caught my eye: Tracy Deliman SP6CIAl. FEATURES ''Wh-' 'I a six l el1~r word meaning odious Don Inmln rt!ptile! " I tried 'Edilor ' and it didn·t wen-k. Ra mon llmOrl out of . True words, I've learned already, and I 'm new 4 INTRODUCTI ON TO COMPUTER MUS IC Copy Editor by Omis RlXlds It Ihe job. San Le Forge 9 PROGRAMMING PROBl.EMS
fURDltmfR'TltL~ Figure 1. Eogene Uten. the earilloneur. reprogremmlng an early a.lgi .... carillon. (I'hotogrsph from [3]1
The Renaissance
As in most other technical matters, the Dark Ale~ in Europe C. Roads produced nothing of note, and it is only with the Renaissance Experimental Music Studio, Rm 26-311 that new interest in automatic music began to bu rgeon. In the Massachusetts Institute of Technology 1500's Leonardo Da Vinci constructed a mechanical spinet Cambridge, MA 02139 piano and drums 13, p. 16 J. A. K.irchner'~ Musirgia Univel$alis ( 16 50) details some fantastic plan~ for I steam-driven organ. Introductton (Figure 21
This article will introduce the interested reader to the fundamental concepts and techniques of compuler music as II is practiced today. First, the history of automated music (older than you might at first imagine) will be surveyed Next, the basics of sound synthesis via computer will be examined, and the technical requirements for high -fidelity SQund will be outlined. Then sound synthesizers, both the older analog and the newer purely digital breeds, will be discussed. Composing programs which embody systems of musicallOtelligence will be introduced. along with some other applica tions of computers to music, such as music analysis and printing. Many references are provided for further investigation.
Although some technical detail is necessary in discussing specific methods of sound synthesis, this article is self co nta ined; any intelligent person should have little trouble understanding the fundumentals of computer music.
The Early History of A uto ma t ~ Music
Automated music goes back a lot further than most people think. But then it seems that music and symbolic thinking have long been associated. For example. the Greek Pythagoras (d. 497 B.C.) was both a number theoretician and a music theoretician. The germ idea of automatic music. i.e.. a music played WJthout a musician. must be traced to the ancient Chinese wind·chimes r I) which, powered by gusts of wind, not only generated sound but also did OQt require compositional preprogramming. Melodies and harmonies were generated both by the hung structure of the chimes. and also by the wind patterns of the day. M""hIJWlJCflN'" t I. a.-:-~"-'-' -fW-. _ -.._/>.1_ IIUG! By the Fourteenth Century, the Iranian astronomer and mathematician Jamshid ben Mas'ud ben Mahmud Ghiath ed·Om al·Kashi had invented a pla neta ry computer for computing the longitudes of the Sun, Moon, and visible planets 121. This was a very early and inventive development, and we should admire this scientist. However, in the 1200's Figure 2. A de$ign for. stum·powered organ. taken from some Dutch musical engineers, had devised some carillons (a carillon is a chime of bells) which could play pre Muwfgia Uniwlf'Alis (t6501 by A. Kirchner. programmable melodies and harmonies automatically. These programmable carillons were driven by a revolving cylinder of wood or iron, studded with pegs which triggered a bell-ringing mechanism. The revolving cylinder was Baroque AndroKles covered with holes (analogous to the binary "zero"), and by placing wooden pegs (analogous to the binary "one") in It was in the Baroque period of the 18th century that some of various holes. different melodies and chords could be programmed (digitally!). Some Flemish carillons had ten the most extravagant automatic music devices were contrived. thousQnd locations (holes) for the insertion of note pegs (4). The French during this period exhibited a curious fascination with robots which played musical instruments, which Buchner 131 calls "androides." The most celebrated maker of musical androides was the mathematician and mechanic Jacques de Vaucanson (1709-1782), who exhibited a flute-playing androide in Paris in 1738. Audiences refused to believe that Figure 3. "The Clawcin PI-ver" by Jacqu.t-OrOl, • mUlical the robot was actually playing the nute; they thought that robot buill in the 18 th cenNry. (I'holog.-.ph from [31.1 Another early mechanical music pioneer was F. Engramelle has continued to preoccupy h.imself with the possibilities of to mention here. Some visionary composers were anxious to (1727-1781) who was one of the first to concern himself mechanical performance, specifically player· piano mecha begin experimenting with these resources; however, most of with automatic music printing. "His idea was to construct nisms. Conlon Nancarrow's piano music would be impossible these new instruments were in scarce supply. The composer an apparatus able to write down automatically whatever was to perform without mechanical means; it stands as an example Edgard Varese traversed the country vainly trying to interest played on a piano" (4, p. 20]. The Londoner Rev. Creed of the extension of the domain of possible compositions engineers and the companies they worked for in the possi· presented a paper in 1747 to the Royal Society which through automated processes [71. What mechanical instru bilities for new, electronic musical instruments ]8J. Composer demonstrated the possibility of automatic music transcription ments are left are today controlled by microprocessors [Figure Henry Cowell conceived of an electronic device for auto from a keyboard. By 1774, such a device had been constructed 61. matically performing complicated cross-rhythms around 1916; by the Berlin mechanician Hohlfeld. Tones played on the key he finally paid for its development in the 1930's [91. board were recorded in a telegraphic notation which could be easily transcribed to common music notation. Although the tape recorder was invented in 1935 by AEG, under the German name magnetophone, it was not until the Even earlier, the /irst electric instrnment was built by the 1940's that its tremendous musical potential began to be Jesuit Father La Borde in 1759. The device was an electric tapped. In 1944-49, the Frenchman Boisselet composed a carillon (electric bell-chimes); by pressing a key on a key symphony for a large orchestra with piano, organ, Ondes board, an electric circuit was activated which rang the Martinot (electronic instrument), harp, oscillators, and appropriate bell. "magnetophone" (10, p. 621.
Automatic Music Boxes In 1948, the French engineer and composer Pierre Schaeffer presented a "concert of noises" over French radio. Inter In the 19th century, automatic music boxes enjoyed great estingly. Schaeffer's pioneering experiments wi th recorded, favor in both Europe and the United States. In deed, only with natural sounds (which he called "musique concrete," a term the introduction of the phonograph in the early part of the which is still extensively used) were based on phonograph 20th century was the heyday of the music box ended (5]. record technology. Another significant event in the history of electronic music was a visit in 1949 to Be ll Laboratories The earliest music boxes played metal cylinders-the same as by the German physicist and acoustician Werner Meyer most of the tiny boxes we see in gift and souvenir stores. In Eppler. There Meyer-Eppler saw demonstrated t he Bell Labs the 19th century however, music boxes were developed Vocoder, which had been developed in the late 1930's. This around disk technology taken to grand proportions. The device, which so impressed Meyer-Eppler, was capable of Figure 6. The Marantz reproducing piano, called thl Piano German Paul Lochman introduced in 1885 a music box which cordv. equipped with a digital procenor, control and driver extracting the formant information from one signal (say, a played circular disks called a Symphonium. Another Leipz.ig circuitry, and a digital C8$!lettl machine. An input/output human voice) and using this information to process another outfit called Poly phon Music Works made a similar device soon Figure 4. A large disk musiC&1 oo)C-tne Fof'tuna "MaNeI" terminal may also be allached to the piano for progammable sound, such as a flute playing a melody. The result was the thereafter. After some vicious lawsuits between the two over madl in Leipzig. The machine plays 26-inch music disb, control, ThII device is capable of '1istening" to one's piano sound of a "talking flute." Meyer·Eppler used the Bell Labs patent rights (Lochman lost) disk technology spread through and holds within its cabinet a reed Otg.an, drum, end triangle. performance and then reproducing it. Transformationl on thil Vocoder in lectures in Germany; a representative from the out Europe and most particularly to the United States. (Figure The mechanism is activated by thll insertion of a coin. recorded performance ani then po$$ible. German radio attended one of these lectures and was intrigued 4] The Regina Musical Box Company of New Jersey made a by the possibilities of setting up a studio for experimentation large 27-inch disk machine; "undoubtably the best disk The Rise of Electronic Music with elektronische musik. The first broadcast of electronic machine made either before or since; it had two combs, music experiments occurred in 1951. In America, the com comprising all 172 notes tuned in chromatic scale, and In 1865, Alexander Graham Bell hit upon the idea of trans poser Vladimir Ussachevsky gave the first public demonstra embracing over seven octaves. Time of playing this disk were mitting speech by electric waves; he actually achieved his goal tion of tape mUJic (using the newly-developed Ampex tape over two minutes. Nothing in automatic music had e~er been by transmitting intelligible speech in 1876. This could be seen recorder) on May 9, 1952. Louis and Bebe Barron began to heard before like the 27-illch Regina, and they soon became as the beginning of serious efforts to link the audio domain to use electronic sound generating equipment to produce film popular the world over ... The machine was displayed at the electric technology. The first major storage medium for scores for such science-fiction classics as Forbidden Planet Crystal Palace in London" {5, p. 32]. audio was developed by V. Poulsen of Copenhagen, who intro (l954){111. duced a steel-wire recorder in 1902, Introduction of the Phonograph, End of the Mechanical Age Automatic Electronic Music By the turn of the century, pressures from within music itself The next major innovation in music boxes occurred in 1896 were leading to an expanded view of possible musical sounds. Shortly after the development of the first electronic computer, when G. Brachhausen of the Regina Company patented a self Concurrently, technical means were improving, making such the Enaic in 1945, organ manufacturers in the United States changing disk machine. The mach ine held a magazine of twelve notions as an expanded musical sound universe feasible. By fa r began introducing op tions for rhythmic accompaniment, based disks. By inserting a penny, the selected disk could be played. the grandest conception from around this period (1903) was around sequencer (relay) type tech nology. These very By making the music disks randomlY ' accessible, the Regina the gigantic Teleharmonium invented by Dr. Thaddeus Cahill. primitive "automated rhythm sections" produced incessantly Company hoped to stave off the growing popularlity of the Cahill's plan was to broadcast electronic music on a subscrip repeating percussive sounds. The closest things to a "program recently-introduced phonograph put out by Edison's company tion basis over the telephone wires being installed so rapidly mable" analog music synthesizer we re the Mark I (1955) and in the late J 890's The heavy-metal disks and instrumental around the United States. However, inductive interference Mark /I (1964) synthesizers built by Olson and Belar of RCA. gadgetry contained wi thin the music boxes we re, however, no created by the Teleharmonium's sou nd signals Jed to Although they were intern ally entirely analos. they were match for Edison's system, which could record any perform complaints fro m regular telephone customers. Despite an driven by musical specifications coded on a wide, punched ance, particularly vocal/instrumental combinations. enomlOUS investment, the project had to be cancelled. By this paper-tape. time, Cahill had assembled "thirty carloads" of tone The last versions of the automated boxes were also the ge nerators, whose tones could be combined to produce music The introduction into the marketplace of vol,age'controll~d grandest in scale. These huge contraptions, called "Orches 161. synthesizers in the mid-1960's brought new possibilities for trions" were the embodiment of the concept of the automated electronic music expression to a much wider group of orchestra. ] Figure 5 1 In 19 13, the Italian painter Luigi Russolo issued his famous musicians. [Figure 7] By varying the control-voltages applied manifesto in which he called for a new sonic art form based on to the various sound-producing modules, it was possible to By 1900, the age of mechanical music instruments was over. noises. He implemented his ideas by bu il ding a collection of change the character of the sound being produced. Nearly Even so, the composers Haydn, Mozart, Beethoven, and noise-making instruments. every manufacturer of analog music synthesizers offered a Debussy, among others, had all written pieces fo r mechanical more-or-Iess crude analog sequencer module as an option. instmments. The last sign of organized interest in mechanical Meanwhile, the development of the vacuum tube in 1908 by Using an analog sequencer, a sequence of voltages for control· automated music was a "Mechanical Music Festival" held in Figure 5. An "Orchestion" - automated orchestra - built by Dr. Lee de Forest led to a spate of electronic music ling some musical parameter (such as frequency) could be 1926 in Baden, GermallY, which featu red works by M. Wefte of Ge rmanv in t862. Notice the va st range of pipes instruments, including the Theremill (1919), the Trautonium preset. The sequencer could then cycle through these voltages Hindemith, Toch, and M(inch. One 20th century composer and bellows, and the ban drum at top center. (1930), the Ondes Martinot (1928), and 01 hers too numerous to produce a repeating melody. ( Figure 8] Continucd on pg. 38 6 RECREAT IONAL COMPUTING MAY-JUNE t980 7 HELP CREATE THE FUTURE!
Help make Recreational Com pilling an exciting magazine about the world and computing. We are for everyone not just for kids or just for computer wizards. Computers are part of the future. To PROGRAMMING PROBLEM S survive in an increasingly technological world ordinary people need computer COMI NG NE XT ISSUE : BY BOB ALBRECHT. DON ALBERS AND JIM CONLAN skills. We need your input and your help, An in -depth investigation of the various computer simulation and arlN.,.Cles/programs fan tasy games~epic games - how t hey are built, how they are fashion PROBLEM # 15 ONE WA Y TO FLY PROBLEM # 16 FLYING FR OM HE RE TO THER E ed by master gamesmiths, and how you can make such games yourself. toons / artwork The town of Westerly is 100 miles due west of the town of We assume that you have already read, and perhaps solved, Easterly. Charlie L., an experienced pilot, flies a plane from PROBLEM #15 ONE WAY TO F LY. soft ware reviewers simulation of the migration of Westerly to Easterly. complete with color Well, Charlie moves around a bit. Unfortunately, our program sound for Ihe Atari. • Charlie's plane cruises at 120 mph. for PROBLEM # ISis useful o nly for west to east flights of """"""<' is published by Company, a non • The wind is from the south at 30 mph. 100 miles when the wind is from the south. So, let's make a corporation chartered selection of • Since Charlie is an experienced pilot, he heads south of more useful program ...f1ying from HERE to THERE with east by just enough to compensate for the wind. His plane tpe wind from any direction. f:;~~d":;":~d~~edUCatiOnal travels in a straight line from Westerly to Easterly. N No"" D irectio n of Dight path, In degrel!'. Wind (30 mph) HERE ----"L.__ ...... Hl!ading of plane
s N Symbols, and Computers Actual Dilht path Actual filght path THERE "''',n. Graphics, and Music Wutnly Easterly
Charlie'. plane heads E Computers in Education thls way at 1 20 mph. Charlie, as you may recall, is an experienced pilot. He points his plane just enough into the wind so that it travels in a Ques tions. straight line from HERE to THERE.
amusing. I'd like to submit them for possible Q I. What is the heading of the plane? T he heading is the You are given - direction the plane is pointed, measured in degrees clock wise from north. of my interests and qualifications. .. Direction of desired actual flight path from HERE to Q2. What is the actual west to east speed of the plane, along "''''p,tiO" of my interests, my computer TH ER E, measured in degrees clockwise from north. the flight path? Q3. How long does it take Charlie to fly from Westerly .. Distance from HERE to T HERE. to Easterly? .. Speed of Charlie's plane in the direction in which it is Write a program to compute the heading, the west to east poiflled. speed and the time of flight given the speed of the plane and • Direction the wind is f rom, measured in degrees clock· the speed of the wind. A RU N of your program might look wise from north. like this. .. Speed of the wind.
RUN Write a program to compute the heading of Charlie's plane SPEED or PLANE? 120 SPEED OF WIND? 30 (in degrees clockwise from north), the speed along the actual flight path and the time of flight from HERE to THERE. HEADING IS 104.478 DEGREES For the fligh t from Westerly to Easterly (PROB LEM # IS), FLI GHT PATH SPEED IS 116.19 MPH a R UN of your program might look like this. TIME OF FLIGHT IS .860663 HOUR S RUN Remember, Charlie is flying from Westerly to Easterly, a DISTANCE FROM HERE TO THER E? 100 DI RECTION FROM HERE TO THERE? 90 distance of 100 miles. Strange, but true, the wind is always SPEED Of' PLANE? 120 from the south. The independent variables are the speed of the DIR ECTION WIND IS FROM? 180 pla ne and the speed of the wind. SPEED OF WIND? 30
8 R ECREATIO NAL COMPUTING MAY·JU NE 1980 9 HEADING IS 104.478 DEGREES For all positive integers greater than one, the sum of the FLIG HT PATH SPEED IS 116.19 MPH divisors of the number is greater than the number. TIME OF FLIGHT IS .860663 HOURS PROBLEM # 17 ANOTHER WAY TO FLY NUMBER DIVISORS SUM OF DIVISORS New from Osborne '·'-Hill Before reading this problem, first read PROBLEM # IS ONE 2 1,2 3 6502 PET@ WA Y TO FLY, where you will learn about the towns of 3 1,3 4 Westerly and Easterly, where the wind is always from the 4 1,2,4 7 Assembly Language Personal Computer south. 5 1,5 6 6 1,2,3,6 12 Programming by C. Ooo,h" & J. En,,, Archie B., who soloed recently, flies his plane from Westerly Guide ~~~~~~~~ New this Spring to Easterly. Archie is a very straightforward and direct sort by Lance Leventhal j ~!"II)'\:;", A step-by-step guide for the computer novice who of person. He simply points his plane directly at Easterly, "the book that will prob wants to learn to program and operate the PET computer. ignoring drift due to the wind from the south. His plane, of The sum of the divisors of six is twelve, which is exactly It covers PET programming techniques. graphics. operazion, and course, drifts to the north. Does this bother Archie? No, two times six. Six is called a perfect /IImzber. ably get the reputation how to cope with many PET peculiarities. #30-6 SIS.OO he simply keeps changing headings so that his plane is always as being the 6502 bible" pointed directly at Easterly. Therefore, he flies a curve as in .. A perfect number is a positive integer for which the sum Il1Ierfare Age dicated in the following diagram. of the divisors of the number is exactly twice the number. January 1980 PET" and the N Six is the first perfect number. The second perfect number Learn 10 increase Ihe capabilities and performance or your IEEE 488 , is 28. 6502-based computer by programming in Assembly Language. Bus (GPIB) Wind (30 mph) by E. Fisher and C. W. Jensen DIVISORS OF 28: 1,2,4,7,14,28 #27--6 $12.50 SUM OF DIVISORS: I + 2 + 4 + 7 + 14 + 28 = 56 available on interfacing PET to Actual fliiht path S TO ORDER. please specify book tizle. order # . quantizy, and your But, of course, some people sa id , "What is so perfecl about return mailing address. Enclose check or money order for price of PET interface to oontrol power each book ordered. plus 75¢ per book for shipping. California resi I and other inslrumenzs. that?" Others pointed out that, if you added only the proper dents please include sales tax. Allow 4 weeks for delivery. For of its authors divisors, you got the number itself. faster shipment or credit card order. call (415) 548-2805. PI Z''"' ,t PROPER DIVISORS OF 6: 1,2,3 120 mph SUM OF PROPER DIVISORS: I + 2 + 3 '" 6 Mail zo: OSBORNE/McGraw-llili 630 Bancroft Way. Dept. RC (j\OSBORNE/McGraw-Hili Berkeley. CA 94710 And again:
PROPER DIVISORS OF 28: 1,2,4,7, 14 SUM OF PROPER DIVISORS: 1+ 2 + 4 + 7 + 14 = 28 100 miles Reader Service Amazing, delightful and ... perfect? Well, anyhow, interest ing. The first five perfect numbers are: CLUB & CLASSROOM DISCOUNTS. PEOPLE'S COMPUTER COMPANY PUBLICATIONS MOOVINGt 6,28,496,8128 and 33550336. Write a program to help· you answer the following questions. Recrearional Compuring IMPORTANT That is flOI our problem. Dr. Dobb's Journal QI. How long does it take Archie to ny from Westerly to Please advise us of address changes 60 days in ad· Clubs. users groups, schools and any others interested may Easterly? Our problem is to find positive integers for which the sum of vance and attach your magazine mailing label here. Q2. In the diagram, note the xy coordinate system. Complete the divisors is exactly equal to three times the number. take advantage of discounts for Quantity OrdeT1 of each of our Please clip this notice and mail. or send us a reason· the following table showing the x and y coordinates of magalifles. See terms below. able facsimile. Archie's plane as functions of time. The first such number is 120. All orders will be shipped via UPS~faster than the post office I DISCOUNT SCHEDULE (minutes) x (miles) y (miles) DI VISORS OF 120: 1,2,3,4,5,6,8,10,12, IS, 20, (one year) 24,30,40,60,120 QUANTITY DISCOUNT RC OOJ 10 20 SUM OF DI VISORS: 360 Regular S ubscrip- Nan,e (pleas~ pm)! n~w 'nformationl 30 tion Rate/Yaar nona $10 $15 The second such number is 672. You compute the divisors g etc. 5-10 copies 10. 13.50 Addres!> and the sum of the divisors. 11 -24 copias 15. 8.50 12 25-49 copies 20% 8 12 Is there a third such number? If so, what is it? Is there a fourth 50-74 copies 25. 750 1'.25 Keep 'em nying! number? If so, what is it? and so on ...do es it ever stop? 75 + copies 30% 6.50 9.00 Stat~ Zip Code TERMS PROBLEM # 18 MORE THAN PERFECT? Is there a number (positive i.nteger) for which the sum of • Good in the U.S. only. divisors is equal to four times the number? More than one • Quantity orders must be made up of one title only ~no Country One is one and all alone and ... Yes, one (I) is unique in such number? How about five times the number ... oh well, mixing among titles. many ways. It is the only positive integer with exactly one di this could go on forever! • All copies must be shipped to same n8me and stret!t addll!SS visor which (of course) is one. It is also the only positive {no P. O. box). integer for which the sum of its divisors is equal to the number Please send answers to any of the above questions. TeU us how • Payment must accompany order~check or money order itself. you got the answer. We'" would like to see programs that you only. used to get these answers, especially if they run on home/ • Minimum one·year subscription. P.O. Box E, 1263 El Camino, Menlo Park, CA 94025 .. The sum of the divisors of I is I. school/personal computers . 10 RECREATIONAL COMPUTING MAY·JUNE 1980 " through $FFFF) are used to indicate what the processor is to do when power Accumulator Addressing. Used to modify tents of either the X index register or 6502 captures in its flag register some of is applied or an interrupt occurs. An the result currently in the accumulator. the Y index register. The result, truncated the state information produced by each interrupt is a signal from the outside AU instructions are a single byte. to eight bits, is used as the address. operation on data. For example, if an world to the processor indicating that addition produces a zero result, the Z it should suspend whatever it is doing Absolute Addressing. Allows you to Indexed A bso/ute Addressing. An in bit in the flag register is turned on. This ~rogramming and pay attention. specify the address in the instruction. struction using this form is three bytes bit can tnen be tested with a BEQ or a All are three bytes long: an operation long. The specified index register (either BNE instruction to modify the flow of Each personal computer has different byte followed by the low order byte X or Y) is added to the second byte to control for the program. Branches in the expectations about the use of memory. of the address then the high order byte. form the low order effective address; Often some addresses are preempted any carry is then added into the third Figure 2. '([be 6502 ]n 6502 Assembter Conventions for the BASIC interpreter. Certainly Zero Page Addressing. Just like the abo byte to form the high order portion of some page zero locations are used by the solute address mode but only for page the address. system and should not be modified by zero. Instructions are two bytes long. Each instruction appears on a separate the programmer. Other memory is reo Indexed fndirect Addressing. A two line. Each line has the form served to communica te with peripheral fmmediate Addressing. Rather than byte instruction. The second byte and devices; still other memory may be map· specify the address of a constant and the X register are added together to give LABEL OPCODE OPERANDS COMMENTS ped into the user's terminal as a display. then demand storage space be allocated an address in page zero. The contents To know what memory you can use, for the constant too, the 6502 allows the of that location and the one following The LABEL and COMMENTS are op BY ERNEST GOLLU X consult your particular machine's docu constant to appear in the instruction. it (which must be in page zero) is taken tionai. Some opcodes do not require an mentation. These instructions are two bytes long; to be the desired address. OPERANDS field. The LABEL, if it ap The processing heart of most personal The flow of execution can be changed one operation byte and the immediate pears, must be the first item on the line. computers on the market today (the by branch instructions, jump instructions, If you're going to do any serious amount data byte. Indirect Indexed Addressing. Another COMMENTS must start with a semi Apple, the Atari, the PET, the Kim, or jump subroutine instructions. In the of programming in the 6502's native two· byte instruction. The second byte colon (' ;'). and more) is the 6502. Its low cost and latter case, execution can resume at language, you should have an assembler. Relative Addressing. Used for branches specifies a location in page zero. The simple design have made it the work the instruction following the jump sub An assembler is a program which con· only, relative addressing specifies a lo value at that location and Yare added to The form of the OPERANDS field de termines the addressing mode of the horse microprocessor of the personal routine since the program counter is verts mnemonic representations of opera cation -128 bytes backwards Of 127 give the low order byte of the effective instmction. T he various forms are: computer industry. Most personal com saved on a last·in-first-out list or stack. tions and operand references into bytes forward from the instruction address. The high order byte of the ad puter users don't have much contact This stack uses the stack pointer to keep machine instructions. If you're just foUowing the branch instructions. These dress is the word following in page zero absolute Qr page zero with the 6502 - they program their track of where the most recent return playing around, you can do the assembly instructions are two bytes long. Relative with the carry (if any) incorporated. address computer primarily in BASIC. But if yourself by hand by looking up the op· address,X absolute or page zero indexed address is stored. The two registers addressing has the property that it need byX you really want to understand com labeled X and Yare index registers and code in a machine reference manual and not be modified if the program is moved Abso/llte Indirect. A three-byte instruc· adding the appropriate addresses. It's address,Y absolute or page zero indexed puters, eventually you have to contend are used to access data from memory. to another location in memory since tion. The second and third bytes store by Y with the raw machine. The flags register contains the status of a good exercise but rapidly becomes it depends only upon the relative posi· and specify the address of the address. :fkonstant immediDte the most recently executed operation and tedious. tion with respect to the program counter. (address){) indexed indirect Programming in machine language is is used to control conditional branching. The sequence of instructions executed (address), Y indirect uldexed quile different from programming in a Figure 2 summarizes the features of fndexed Page Zero Addressing. This is a is called the flow of control. In any in· (address) absolute illdirect high leve! language, The programmer has Both the program and data are stored most 6502 assemblers. We will use those two-byte instruction. The second byte teresting program the flow of control to keep track of many more details. in the computer's memory. For the 6502 conventions in the programs we develop of the instruction is added to the con- depends upon the data entered. The The assem bier will generate page zero He must worry about the representation the maximum memory size is 16 bits below. Figure 3 lists Ihe 6502's instruc or absolute addressing as needed. of the information and how to access or 65536 bytes. That's the largest value tion set and indicates which condition it. In return, he gets some additional which can be represented in 16 bits flags (if any) are affected by the instruc Assemblers also provide directives to flexibility and additional performance. or two S-bit bytes. Since the 6502's tion and which addressing modes are , control allocation, initialize data areas, world is really 8 bits wide, memory is provided. and maintain assembly-time variables. ACCUMULATOR The 6502 is an eight-bit proceSSOf, which divided into 256 pages of 256 bytes A I Those provided by standard 6502 assem means that it processes information each. A single byte is adequate to specify The operation set is rather sparse. You , blers are: eight bits at a time. All data, insofar as a location within a page. Addresses are can add and subtract (carry included) , INDEX REG ISTER Y .BYTE 141 initialize byte data the processor is concerned, are a string 16 bit numbers. They could be stored S·bil numbers. You can shift right or :oJ, of eight bits. Some inSlmctions inter· .WORD 444 initialize word data (LSB, in either of two ways in the computer left one bit; you can rotate right or MSB) , INOEX REGISTER X pret those bits as a binary number with memory: most significant byte then left one bit through carry. You can per .DBYTE 555 initiDlize word dIlta (MSB, values ranging from 0 to 255 detlimal least significant byte or the reverse. form bit·wise and's, or's, and exclusive , LSB) (unsigned) or -128 to 127 (signed). The assembler (F igure 2) provides or's. And that's about alL More complex " .TEXT "hello" iflitiDlize ASCII text The programmer can interpret the ways to store data in both forms, but operations like multiplication must be eo" "" PROGRAM COUNTER .END end of assembly number in any way he wants. For ex the convention for addresses is for the constructed from sequences of these , A"'B+S equate (used for a/locotion ample, the number 65 could represent least significant byte ( LSB) to be stored operations. But that's typical of most and manifest constants) , STACK POINTER equau used for allocotion the ASCII character "A" in one context, first (lower address) and then the most eight-bit processors. " and it could be 26 + I , a value in some significant byte (MSB). With that order 1NI v I, 0 , 1,1,1 PROCESSOR STATUS REGISTER. "P" Constants may be expressed in a variety computation, in another. 1he 6502 mani ing the processor does not need to save AddreSSing is, on the other hand, unu of different bases: pulates data by moving them from anything temporarily when computing sually rich for a microprocessor. There CARRY (BIT 1) 1 1 ZERO memory into registers internal to the are, aU in all, thirteen different ways an address. INTERRUPT DISABLE 150 hexadecimal (base 16) data processor, performing the desired opera an address can be specified. Not all DECIMAL MOOE BREAK COMMAND 80 decimal number system tion or operations and then moving them T he processor has certain built-in expec modes exist for all instructions however. FORTHCOMING FEATURE @120 octal number system back into memory. The register comple tations as to how memory is to be used. The formats of instructions are shown OVERFLOW %1010000 binary number system ment of the 6502 is shown in Figure I. Page zero is a good place to store fre in Figure 4. To be able to program ef NEGATIVE 'A ASC II character The accumulator is used to perform all quently used data since the processor fectively, we must understand how each '+7 offset to location counter Figurtl 1. arithmetic and logical operations on data. has a space efficient way to access them; addressing mode determines its effective The program counter contains the ad in addition, by using a pointer in page address. Most assemblers allow address expres The regist&r complement of the 6502 includes II 16·bit progllllm count&r, lin S·bit dress of the next instruction in memory. zero, data elsewhere in memory can be sions anywhere addresses are allowed. ac:CumuJalor in which arithmetic and logitllJ operations are performed, two S ·bit index It is incremented as each instruction is accessed efficiently. Page one is pre Implied Addressing. The address is part Some provide for relocation, binding registers. an S ·bit stack pointer int&rnally adjusted to address memory Joclltions 010016 processed so instructions aTe executed empted for use as the stack. Some loca of the instruction. These are all one of externals, macros, and other advanced through 01FF 16. and an S-bit flags regist&r which holds the current status of th& machin&. from low addresses to high sequentially. tions in high memory (addresses $FFF A byte instructions. features.
12 RECREATIONAL COMPUTING MAY·JUNE 1980 13 The address TABLE is the first (O-th) 6502 are all relative and are limited in CLC element of a table of codes whose valu~ op operation condition range to - 128 bytes back or + 127 LDA A is the new (translate) code and whose SCOpy LOX 110 code codes bytes forward from the instruction fol ADC B LOOP ordinal position is the old code. For LOA (S,X) STA A STA (D,X) lowing the branch. Longer branches, character data this table would be either if they are needed, are constructed by LDA A+ I BEQ DNE ADC B+ I 256 or 128 bytes long, depending upon IN C S inverting the branch condition (not the local conventions about parity. equal rather than equal, for example) STA A + I BNE SCI INC + and branching over an unconditional Notice that the carry is propogated S I The stack operations PSA and PLA 51 INC D jump to the desired location. Jumps are NV BD I ZC from the low order byte addition to the are used to save and restore the value BNE LOOP not conditional and may be either direct high order byte addition just as it should INC D+ 1 ADC Add with Carry to A of the accumulator to prevent the user or indirect. be. This same approach can be general from inadvertently destroying useful BNE LOOP AND And to A :m; ized to additions of arbitrary length. DNE RTS data. ASL Shift Left One Bit Another mechanism allows for sub BCC Branch on Carry Clear routines or procedures. A lSR instruc Coin Flipper. This is a subroutine which String Copy. Strings are' simply linear This program destroys both the A and X BCS Branch on Carry Set tion places the address following itself is meant to be called to get the result arrays of characters. In one useful repre registers. II uses the indirect addressing BEQ B!anch on Zero Result onto the stack and then jumps to the of flipping a coin; it appears in a dif sentation one associates a string with modes to load characters and store them. BIT Test Bits in Memory with A specified location. A RTS instruction ferent form in the Programmer's Toolbox its starting address and agrees that all The increment and branch operations 8MI Branch on Minus Result executed later causes the program to in this issue. Executing the instruction strings will be terminated by a zero byte add one to the 16-bit values of the point BN E Branch on Result not Zero resume execution at the location follow (NUL). Passing around variables con ers to select the next element. The value BPL Branch on Result Positive ing the most recent lSR. The stack is JSR FLIP taining the address of the start of the of the condition code is set by the load BRK Force Interrupt or Break limited to 256 bytes (one page) so string is then equivalent, in some sense, and tested to determine whether the BVE Branch on Overflow Clear the maximum subroutine nesting level sets the accumulator to either zero to passing around the string itself. routine should terminate. BVS Branch on Overflow Set is 128. The stack can also be used to (heads) or one (tails). Somewhere in CLC Clear Carry Flag store data using the PHA and PtA, memory there is a two-byte number, The problem at hand is to copy one Machine language programming is really CLO Clear Decimal Mode PHS and PLS instruction:.. We can now SEED, which has been initialized to string into another. The routine below simply a matter of fitting together CLI Clear Interrupl Disable try our hand at a few small 6502 pro some non-zero value. The FLIP routine is does this using the powerful addressing some complicated low level primatives CLV Clear Overflow Flag grams to see exactly how these instruc modes of the 6502. Two pointer vari to make higher level operations, and CM' Compare M emory and A tions can be fit together to accomplish FLIP CLC ables are allocated in page zero. These then using those operatio ns to make even CPX Compare Memory and X useful work. We'll write things out in ROL SEED are Sand D; both are 16-bit values. higher level primatives. It has its own CPY Compare Memory and Y assembler language rather than machine ROL SEED+I We initialize S to the address of the fascinations; one of the joys of program DEC Decrement Memory By One language so that they are human readable BCC FLJ fiist character of the string we want to ming is to find a way to construct a really DEX Detrement X by One to some extent. We'll use variable names LOA SEED copy, and we initialize D to the address elegant (and often, sad to say, inscru DEY Decrement Y by One like A and T EMP, but you should re EOR #>03 of the area in memory into which we table) way to solve a problem on a parti EOR Exclusive-or Memory with A member that Ilariable /lames in an auem STA SEED want to copy the string. Then we call cular machine. Enjoy. LDA SEED +1 INC Increment Memory by One bier represent addresses not I'alues. the routine with a JSR EOR #>80 INX Increment Index X by One The value of a name, say A, is its place STA SEED + I INY Increment Index Y by One I in memory and not the contents of that LDA #1 JMP Jump to New Location place in memory. To gel the contents RTS operation code JSR J lllllp and Save Return you have to load the value into a working FLI LDA 110 Figure 4. LDA Load Ace from Memory register like the accumulator. RTS low order address byte 6502 In stru ction Formats by Addressing Mode LDX Load X from Memory Add a COllstant to a variable. Suppose high order address byte LOY Load Y from Memory we want to add 5 to the value of byte Now this is a bit more complicated. The displacement LSR Shift Right One Bit variable A. This can be done using the sequence of ROL's double the value of NOP No Operation instructions SEED in memory. The high order bit is example foonat mode ORA Or Memo ry to A tested and if it is on, the seed is exclusive PHA Push Acc onto Stack CLC or'd with the constant $8003 and the PHP Push Status onto Stack LDA A result one is returned. If the high order ROL D' ACCUMULATOR PLA Put! Acc from Stack ADC #S bit is off, then the result zero is returned. PLP Pull Status from Stack STA A ADC#I OP DATA IMMEDIATE ROL Rotate One Bit Left In actual fact the infonnation we want The clear carry instruction is necessary ADC $FOlO ABSOLUTE ROR Rotate One Bit Right is stored in the high order bit of the 0' since we do not know what the value of RTI Return from Interrupt constructed SEED and could be re carry is when we enter this sequence. ADC $OF 0' ZERO PAGE ADDRESSING RTS Return from Subroutine covered uniformly to produce a more SBC Subract Memory and Carry from If we had wanted to add one, we could compact routine. That is left as an ex Sct Carry Flag have used ADC $OF, X SEC ercise for the reader. OP INDEXED ZERO PAGE ADDRESSING SED Sct Decimal Mode ADC $O F, Y SEI Set Interrupt Disable Status INC A Code Tramiarioll. Sometimes one wants STA Store Acc in Memory to convert from one character set to which is provided in the instruction AVC $FOJO, X I STX Store X in Memory another, say from ASCII to EBCDIC INDEXED ABSOLUTE ADDRESSING set because it (and decrement by one) ADC $FO IO. Y 0' STY Store Y in Memory or vice-versa. The routine below does TAX Transfer A to X are common programming operations. that efficiently. The character to be TSX OP IMPLIED TAY Transfer A to Y converted is stored in the X register and Add two J6-bit variabies. Suppose we TSX Transfer SP to X then the routine is called with a J SR. BEQ·+5 want to have two 16-bit numbers stored OP D RELATIVE ADDRESSING TXA Transfer Index X to A The routine replaces the value in the X in A and A + I and B and B + I. We TXS Transfer Index X to SP register with the translated value. ADC ($OF, X) OP INDEXED INDIRECT ADDRESS ING TYA Transfer Index Y to A want to add them and store the result back into the storage space for A. Fur CONVERT PSA ADC ($OF),Y DP INDIRECT INDEXED ADDRESS ING Figure 3. there, Jet's assume that A contains the LDA TABLE,X The 6502 operations, the condition codes they affll(:t, and the addressing modes provided least significant byte and A + I contains TAX ADC($FOIO) OP ABSOLUTE IND IRECT for each operation . the most significant byte. To form the PLA sum we use RTS
14 RECREA TIONAL COMPUTING MAY·JUNE 19,., 15 THE ELECTRIC PHONE BOOK A 1M 65 A TAR I PET A Directory of 144 Computerized 5 Y M . 1 APPLE Bulletin Board Systems KIM·1 The 6502 Journal 051
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(Science can be fUn.) The rest is fat. Finally, the most telling blow of all she may have been too sleepy to notice. Fat is a good insulator of body heat relates to the carrier for this device While the measurement of her breast MICROPROCESSOR because it does not have much blood the brassiere, Obviously, this apparel, skin temperature under all these circum flow to convey heat through it. Thus, if worn at all , is only located over the stances may be scientifically valuable and the skin of the breast overlies a layer of breast during the day while the woman personally interesting, its relevance for insulating fat that is different for every is active. The day may be cold or hot. infonnation about fertility seems du woman. This in itself might not be too She may have remembered her sweater bious. The woman undoubtedly will serious a problem. Since it is only neces or not. The man next to her on the bus never even wear this special purpose sary to detect the rise in basal body may have been extremely attractive, or garment when she is in a basal metabolic CoNTROLLED BRA temperature, the absolute values are of state, after hours of sleep. little importance. THE BASAL BODY TEMPERATURE or course, there may be some interesting BY C. S. D. CLANTON, M.D . UnfortunatelY, the skin temperature METHOD OF BIRTH CONTROL algorithm or unusual property of the varies by a great deal more than the half breast skin measurement that has escaped SAFETY FIRST degree of basal body temperature change AS a natural method of birth control, an my attention. I certainly do not know mentioned above, The skin has an im accurate record of the basal body temper everything about breast skin temperature. D. Green Electronics of Glasgow, portant role in the maintenance of a ature (BBT) taken over a period of 3-4 However, before risking possible un Scotland, may soon market micro constant core temperature. Thus, when months can reliably determine the end of wanted pregnancy, thorough experiment processor-controlled brassieres that you take a hot bath, your skin turns red. the interval of fertility - the safe, infertile al data would be needed to convince me. determine the safe and unsafe That is due to the marked increase in time after ovulation. SST is defined as Such experiments would have to be periods in a woman's ovulation blood circulating through the skin. This the lowest temperature reached by a conducted in a substantial number of cycle by analyzing variations in superficial blood radiates heat readily, healthy, rested body during waking women over some period of time, to breast temperature. The micro thus eliminating the extra body heat hours. Immediately preceding ovulation, accumulate sufficient experience to es would automatically measure and acquired from the hot water. If you go the BST of the woman drops (about tablish statistically valid estimates of analyze variations in breast tempera out naked on a cold day, you will see O.2°F). During the follOwing 24-12 reliability and precision. I also tend not ture, providing a real-lime readout the opposite effect. Your skin will hours, a reproductive hormone released to find studies by those who have some of fertility. Not yet finalized is blanch. The blood flow has been mark after ovulation causes the temperature to thing to gain from the outcome very the location for the display. edly decreased to minimize heat loss to rise several tenths of one degree (0.6- persuasive. In fact, I am generally reluc the environment. If you stay out long O.SoF) above the normal BST. To avoid tant both personally and professionally From EE Times, December 10, enough, you will start shivering-an pregnancy, a woman should refrain from to use medical products that are new to 1919. involuntary muscular activity to in unprotected intercourse until her temper the market. I prefer to wait a year o r so crease heat production to help maintain ature has remained elevated for three to see how they work on other physi your core temperature. consecutive days. cian's patients and what the real problems Because I am both a physician and a of the cycle. (Abstention is sometimes are before I use them on myself or any- computer scientist, I try to keep up the method chosen for the unsafe period While it is tme that a woman's core tem- REFERENCES: one else. Usually in that year the product with interesting developments in both though many people find it less than perature is higher over the days following that was heralded by everyone as "the areas. When Dennis Allison called the ideaL) The basal body temperature ovula tion so that she must on average ContrQceptive Technology 1918-1979, best ever" at the time of its announce- other day to ask about a prospective merely keeps the beat somewhat beller be conserving more heat through her skin Robert A. Hatcher, M.D., et aL, Irvington ment has proven to be no better and microcomputer product for a medical than counting backwards fourteen days than before, I would expect this differ- Pu bl'IS h ers, I nc., N ew Y or.k 13 ._'5 often worse then the old tried and true. application, I must admit I had nol heard from the time the next menstmal period ence to be very small compared to the A CooperQtive Method of NQturDI Birth Fo r contraception, I use and recommend about it. The product, located in a is expected. Women who chart their basal effects on skin temperature of the ContrOl, Margaret Nofziger, The Book the barrier methods primarily-condom, braSSiere, is intended to provide an body temperatures often find that their weather or sleeping with more or less Publishing Company. Summerton, TN. diaphragm, and foam-because of their indication of the safe and unsafe periods period does not invariably come exactly covering or adjacent warm bodies. An- S3.25 lack of complications and effectiveness in a woman's menstrual cycle by analyz fourteen days after the temperature shift In ordinary life outside the research other interesting influence on breast if used correctl y (yes, there is a wrong ing variations in breast temperature. anyway, a demonstration of the diffi laboratory, a reasonably accurate core skin temperature is sexual activity. A These books are available from the way to put o n a condom -without My immediate reaction, similar to that culty of predicting the present from the temperature can be obtained with a woman's breasts engorge with blood Education Department, Planned Parent- leaving any room in the tip). These can of many people when it comes to con future. For many people, :lnY available rectal thermometer. An oral thermometer early in sexual arousal; it is one of the hood Association of Santa Clara County, be combined if very high reliability is sidering the conlents of brassieres, was form o f contra ception is often better gives a temperature about I degree F causes of ni pple erection. About half 11 North San Pedro St., San Jose, CA desired. Sometimes, I support other one of excitement. It seemed an answer than none. So if it worked, this device lower but is a fairly reliable indicator of young women have a sex tension flush 95110 (prices include postage) or from methods-the birth control pill, IUD, 10 two problems-finding something might still serve a role as one of the birth of the core temperature as long as it is over their breasts just prior to orgasm, your local Pla nned Parenthood Associa- rhythm with or without basal body useful to do with microprocessors and control options. In addition, though I properly placed, no hot or cold food or though tltis occurs less frequently in older tion. temperature or cervical mucous testing solving a significant social problem. Af saw no mention of it in the news release, liquids have been recently consumed, women. Again, these ,-______.L ______-''- ______, as adjuncts, or even teT a few seconds reflection, my enthu the ability to predict fertility is especially and the mouth is kept closed. A tempera ture taken from the armpit is lower cha nges in blood DAY OF CYCLE the ever faithful with- siasm waned. The principle of operation useful for women who are trying to flow pattern result drawaL It all de- of Ihis device does not seem practical. get pregnant. The theory of operation still and even more difficult to acquire in marked changes in I 10 20 30 40 pends on the objec- seems correct except for one small hitch. with any accuracy or reliability. The skin temperature. _ tives and values of The device evidently measures breast armpit is too far from the body core and They all may be 99c the woman and her skin temperature in an attempt to pro The basal body temperature is the body's too well insulated. Well, the skin is randomly distribu- sexual partner, While dict ovu lat ion. There is a half degree temperature at complete rest, immedi even worse, as those who have seriously ted, but over the I am most interested rise of basal body temperature at the atety upon waking up, before any activity tried to correlate forehead temperature course of such a /\ in both computers time of ovulation which can be used whatsoever except turning orr the alarm with fever know, and the breast poses short period as a and sex (though not with some confidence for family plan clock and reaching for the thermometer. even more problems for the testing of month, they would 980 XXX combined in the ning, in particular the spacing of children, FUrther, it is a body core temperature. core temperature. Most of the breast is almost certainly manner of "Demon though it is not sufficiently reliable to This device presumably measures breast fat. The actual milk-producing gla ndular _, __ill. ~ _~,I_~ prevent pregnancy with the same confi skin temperature and does some form o f tissue in the breast is not very large. It gular variation in skeptical of this par- dence as other more widely used birth integration of this temperature over is the rather firm, somewhat lumpy tissue skin temperature. . ticular application. control methods. Also, it IS still a rhythm time. If that presumption is true, it pre that can be readily felt with the fingers method. That is, some other method of sents 3 serious problem for al least two as the breast is (gently!) rolled over the contraception must be used for much reasons. ribs in a small-breasted woman. The Basal Temperature Will me noticeably after ovulatIOn 18 RECREATIONAL COMPUTING MAY·JUNE 19ao 19 10 REM BINARY TO DECIMAL 20 INPUT AS PT 20: A COIN FLIPPING ROUTINE One can still improve on this by changing the call to 25 T = 0 MID$ in line 600 to 30 X = 1 Many games and simulations need to make only binary 40 I = LEN (AS) decisions rather like flipping a coin. This routine is a MID$( "AEEIOU", 1+6· RND (I») 45IFJ<=OTHENEND 50 FOR L = J TO I STEP - I good way to generate such sequences and, unlike a 60 IFMIDS{AS,L,1)="I"THENT=T+X coin flipper based upon testing tile value of RND(), The frequency of "E"wi!l be closer to that in real names. 65X=X+2 the number of runs generated will be close to that ex Adding 70 NEXT L pected. It is presented below in the programming lan 80 PRINT guage C since it is very difficult to express in BASIC. 605 IF RND (I) < 0.2 COTO 600 90 PR INT "DECIMAL VALUE = "; T The variable seed is a 16- bit integer which is initialized 100 GOTO 20 to some random number. The procedure /lip does the inserts an occasional two-vowel syllable and a very 110 END flipping and returns a one or a zero (heads or tails, o~casional three-vowel one. say) each time it is called. The operation '= +' adds 10 REM SAVE SH*APE *TABLES * * * CONTRIB UT ED BY JOHN TRENHOLME 20 DS:CHRS(4) seed to itself and stores the result back into seed; like 22 IN PUT "NAME OF TEXT FILE?"; AS wise '=1\' performs the bit-wise exclusive-or of seed 25 REM OPEN DISK FILE with the constant and stores the result in seed. The con 30 PRINT OS"OPEN"; AS stant is expressed in octal in the program; in decimal it 40 PRINT OS"REAO"j A$ is 32771. 45 REM SET SHAPE TABLE 46 REM PO INTER The program is based upon linear shift register sequences. 50 POKE 232,0 See Stone, Discrete Mathematical Structures and Their 60 POKE 233,148 Applications, Science Research Associates, Chicago, 70 I: 37887 1973 or Knuth, Seminumerical Algorithms, Addison 75 REM READ AND STORE Wesley , Reading, Mass., 1969, for a discussion of the PT 19: CREATING AND SAVING SHAPE 76 REM SHAPE TABLE VALUES 80 INPUT D theory. TABLES FOR THE APPLE II 90 IF D > 255 THEN GOTO 140 PT 22: PET INPUT WITHOUT BREAKS 100 POKE I, D ,+ a coin flipping routine based upon linear shift register The Apple II and Apple II Plus provide powerful gra 110 PR INT "AT ADDRESS";J; "IS VALUE"; D sequences. Here are two techniques for improving the human phics capabilities, especially when shape tables are 1201=1+1 ,• the primitive polynomial here is Xl S + X + I factors for PET BASIC programs. The first prevents defined and manipulated. Unfortunately, there is no 130 GOTO 80 control from returning to BASIC when an empty line is , cycle length is 32768 available software for the storage and retrieval of shape 140 PRINT DS''CLOSE "; AS , input; the second aliows a default input in response to a tables from diSk, only from cassette. Additionally, 143 REM SET HIMEM TO BEGINN ING return. This trick, with a bit of careful program design 144 REM OF SHA PE TABLE Apple II Plus is not designed to operate in machine " and renumbering programs to start at 60,000 (you do language. This renders invalid most of the discussion in 145 HIMEM: 37887 150 END int seed; ,- the random number seed -, have a Toolkit for your PET, don't you), will protect the APPLESOFT Reference Manual about storing shape most first-time users from needless grief and confusion. tables. What is required is the use of POKE 10 store the EXAMPLE: nip (){ shape table as well as the address at which the shape Shape Table Consisting of one square shape (4 moves) seed = + seed; table begins. 2 if (seed <0) {seed = A 0100003; return (J);} return (0); The following programs were designed to simplify the development of shape tables as well as their storage and It-~3 retrieval. They were written in BASIC Applesoft and CONTRIBUTED BY DENNIS ALLISON will run, as is, on a 48K Apple" or Apple " Plus with a -.4 DOS. If less memory is available, the value of the Binary values for shape definition starting location of the shape table should be changed to a non-interfering memory location (lines 50,60,70, and 00101100 PT 2 1 PRONOUNCEABLE NAMES 145 of SAVE SHAPE TABLES). 00111110 00000000 Here's a name generator for Microsoft style BASIC in Prior to executing the program to save a shape table, SAMPLE RUN COMMENTS the fashion of PTI4 published in the Jan/Feb 1980RC. the decimal values to be stored in the shape table need It runs on the PET but should work with minor changes RUN BINARY TO DECIMAL Convert binary shape to be stored in a text file on disk. These values can be on most Microsoft BASICs. It may be necessary to 700101100 definition to decimal determined through the procedures described on pages DECIMAL VALUE=44 equivalents change the RND function call. 92-95 of the Applesoft BASIC Programming Reference 700111110 Manual and using the BINARY to DECIMAL program DECIMAL VALUE: 62 480 REM NAME GENERATOR SUBROUTINE • defined below. The values can be stored using the MA KE ? (Return) 490 TEXT program provided with the Apple II. Note that MAKE TEXT 500 REM MAKES UP NAMES YOU CAN the values which should be stored for this program are Type String #1 : 71 (Supplied with Apple 11) 510 REM PRONOUNCE. LENGTH IS Index to shape table DECIMAL, not HEXIDECIMAL. BINARY to DECI Type String #2 :10 520 REM RANDOMLY CHOSEN BETWEEN (see page 95 of Apple 530 REM'SA'AND'SB'SYLLABLES. MAL will allow you to convert the binary code (de Type String #3 : 74 } Type String #4 : ?O soft Manual) 540 scribed in the Applesoft Manual) to decimal. SAVE Type String #5 : 744 550 REM NAME IS RETURNED AS 'AS'. SHAPE TABLES will store the data in appropriate Type String #6 : 762 Shape definition 560 RAM locations and define the necessary pointers. Type String #1 : 70 570 A$="" Type String #8 : return f 580 FORSY=ITOSA+(SB-SA+I)·RND(I) If you do not have a disk, these programs can still be 590 AS " AS + MlDS ("BCDFGHJKLMNPRSTVWYZ", 1+ used to place a shape table in memory by deleting lines WHAT FILE NAME? SHAPE TABLE N 19+ RND (1),1) 20, 22, 30, 40 and 140 of SAVE SHAPE TABLES RUN SAVE SHAPE TABLES 600 AS ;- A$ + MlDS ("AEIOU", I + 5 • RND (I), 1) and changing line 70 to I '" 37888. NAME OF TEXT FILE? SHAPE TABLE N 610 NEXT SY 620 RETURN CONTRIBUTED BY JOHN TRENHOLME CONTRIBUTED BY RON LAUGHERY
RECREATIONAL COMPUTING MAY·JUNE 1980 21 The original program translated numbers When you have the program working, random as those selected by the original with thirty places to the left of the deci try adding additional voices (the Atari spinner board. mal (IOO-octillions) and/or twenty-nine has a total of four) which are harmonic· places 10 the right of the decimal (100- ally related to the first. In the SOUND This program was written for the Level II octillionths). For the sake of brevity statement, the first parameter gives TRS-80 but should transport easily to I have included a lisling for a version the voice, the second the note, Ihe Olher systems. of the program which handles numbers third the tone distortion (10 for a pure lone), and the last the amplitude. Add with six places to the left and five places 10 REM. TWISTER MOVE SELECTO R. to the righl of the decimal. To modify new SOUND statements with note values 20 REM. ROD HALLEN, PO BOX 13 this version to perform as my original of N+N and N/2. Change the relative amplitudes as well so that the total 30 REM. TOMPSTONE AZ 85638 program, change line 100 so that in 8 $(1) 40 C$(I)" " RED": C$(2) = "BLUE" I ranges from 1 to 10 and in F$(I) I amplilude (Ihat is, Iheir sum) does not exceed 32. You might also experimenl 50 CS(3) = "YELLOW": C$(4) " "GREEN" ranges from 1 to 29. Add to line I SO 60 E$ (I) = "LEFT FOOT" the data "MILLION." "BILLiON." ...• with the distortion field; dislortion values can be any even number between 70 E$(2) = "LEFT HAND " "OCfILLION." To line 160 add the data SO E$(3) = "RIGHT HAND" "MILLIONTHS," " T EN-MILLIONTHS," o and 14. II RBI ttttftttt+tIIttMtHffHIHHttHHll ttlttt 90 ES(4) = "RIGHT FOOT" .'., " HU NDRED-OCTILLIONTHS." 21 R9\ I IUIBERlBAS .. 100 CLS Lines 180, 190, 560 and 570 would 050 DIM 5(24), F(24) 3t RBI I TRAKSl..A TES Il.tIBERS I 110 PRI NT "COMPUTERIZED TW ISTER" NUMBER have to be redone to reflect the extended 100 REM IN ITIALIZE 41 Ie t INTO oo.l~ 110 T=20 130 PRINT "HIT ENTER TO SEE NEXT MOVE" 51 RBI t JEFFREY C, RUa.E range. Finally, in line 80 more string 140 X = RNO(4): Y = RND(4) space should be "CLEARED" and 120N=121 TRANSLA TION 61 R9\ t PIIIT At«I..ES. ~ 12127/8' 130 FOR I = I T024 150 PR INT @448," ";: INPUT XS FtEII It+fftttt+tl+ftttlftffftl.lfttttltIlIUIlIi FS(5) changed to F $(29). 7. 140 READ U, V 160 PRINT @ 454, E$ (Xl; ''A'' ; C$ (V) ;" ". 81 Il.S:ClEARl lt:DIIVS (21I, UlSI,H(SI 170 GOTO 140 PROGRAM 9t FIJII=! TI'JlI :REAIl.K( I) :)£IT:FIJII=I T08:REA£)TS( I I:)£XT 1505(1) = U 160 F(I) = V 180 END Itl F(JII =1 T02:RfADBi ( I I :)(XT ;FIll I=1 TOO :REACF' (I I :)£IT 110NEXTI II I DATA'I)£' . 'oo' , 'nm','FCUl','F!YE','SU', 'SE\{N' , 'Eloo' 180 I = I 12t 011 TA 'NHt:' , 'TEN' , 'El.I\eI' , 'na.\o£' , 'TlIIRTEEH' , 'FCUlTEEN ' BANAL TUNE 190 REM NOW CYCLE THROUGH STATES BY JEFFREY C. RUBLE 131 MTA 'FIFTEEN' ,'sum' •'SEJ;eiTEEN ','EIGfTEEN' ,'IW£TEEN' 200S0UND O,N, 10,10 14f OIITA'n£NTY' , 'T\oENTY' , ' THIRTY', ~IlIlTY', ' FIffi', 'SIXTY' GENERATOR 210 FOR J = I TO T: NEXT J 151 MTA'SE\-9lTY' ,'EHJITY','NII£TY',' ','OOJSAND' 220 N = F(I) Most people have little difficulty in read II.I 011 TA'TENTHS' , 'IW!f!ErHS' , ' TfOOSANDTHS' , 'TE1HlOJSANTHS ' ,'1UIDIifD-nOO$NIDTt/S' ing numbers with up to nine places to 230 K = I 171 PRINT'THI S PRCreAI'I WIU TAKE A IUtEiER THAT vru IIf'UT AND TRANSlATE' 240 I = 5(1) the left of the decimal (hundred mil FOR THE ATARI ROLLING 181 PRINT 'IT INTO E1O.ISlI , YOO /til£. LlnITED TO I. ?lACES TO nE LEfT' 250 IF RN D (0) >0.5 TH E I = [+ I lions). Ho wever, many people don't 191 PRINT 'IF n£ [(WIN.. AND/CfI 5 PI}CfS TO Iff R[GHT , ~ ccms ARE' 260 IF F(K) <=0 THEN GOTO 210 know the names of the numbers beyond 211 PIIINT '~ D . ' TITLES BY DENNIS ALLlSDN 210 GOTO 200 nine places. Because of this I decided 211 1I$=":FI=" :PRINT:!IrfUT'ItIAT IS YCU! taBER ' ;I\S:PRIN~ 490 REM TABLE OF STATES AND NOTES ~~~~~~~~~~~~~~~ to write a BASIC program for level II 22t IF LEFTI(PI$.J )='-' lIEN PRINT ·t£GAilVf · : IIf:RIGHT.(ItS,LOI(~IH ) 500DATA 3,121,23,0 16K TRS-80 that will accept a number 131 00SlII 52' In the February 1956 issue of Scientific 510DATA5,12 I ,5,121 24t IF VAl(PI$I=. AND VAL(FSl=' ID PRINT 'ZERO ' :OOTO 5~. BY GRAHAM K. JENKINS as input and yield as output the number's American, Richard C. Pinkerto n pub 520DATA1,I21,l9,O 25f R=lfH(IHI-f]l(LEN(M JlSI ' 3 English translation. The program trans lished an article, "Information Theory 530DATA 9.0,9,0 2M IF R:I n£N lI$= ' U'+ItI: ooro 281 540 DATA 11,108,15,121 !ates positive or negative numbers with m IF R=2 TI£N f'I$:."'tPI$ and Melody:' in which he analyzed the or without digits to the right and/or 550DATA 1,121,1,121 SUMMARY 28t FIJI I = \ TO (I• .ENI~' 1131 nature of nursery rhyme tunes using 560 DATA 23,0,23,0 left of the decimal point. 291 !fI.::t'fIDl(ltId+3-i Il-]l.SI :IF VAL(N t l~ 1 Tl£N 311 probability theory. One result of his 570 DATA 13.10S,13, 108 3U rosus 451 :PRINT' 'lBi ILEN(IHI/3-J+1l analysis was a state-transition table for 580 DATA 15,121 , ll ,lOS This article describes and illustrates The basic strategy of the program is 3It IEXT I composing simple nursery-rhyme-like 590DATA 9.0, 17,96 the use of a. BASlC subroutine quite sim ple, The number to be trans 32t IF m o'Y" TI£N 59. lunes. The program below nol only com 600 DATA 19, S2,1, lOS for generatillg large (7 X 5 matrix) lated is input as a string. If there are 33f IF VALIFt l'" 1I£N 591 poses the tune, bUI plays it as well, using 610 DATA 21,0,21,0 headings on a display screell. Head· digits on both sides of the decimal ~I IF VAL (ltI l:' Tl£1i U' the Atari's built-in music generator. ings whose width exceeds that avail 35' PRINT' AND" points, the- string is broken into two UI R=lEH(Fll-flIllEN(FS II3). 3 The tunes it generates sound a bit like nurs able Oil the screen are rolled hori parts and each part is translated separate 371 IF R:I TI£H FS= · ... +H ery rhymes but certainly fit Pinkerton's zOlztal/)' across it ;n a mallller simi ly. The number of groups of three digits 381 IF R:2 n£N FI:'I"+F' characteriza tion - "banal." TWISTER MOVE Inr to that employed ill bank alld in each part is then determined . Each 39t Fill I = I TO lLENIHl/31 travel service promotiOllal displays. group represents a number from zero 4It JtI=I1ID$ (FS.I t3t II -1 h3) All songs are in the key of C and are to nine hundred ninety-nine. After a (II IF VAUNSl=1 Tl£N m si ngle octave only. While these restric GENERATOR group of three digits is translated, its 42t OOSUB 451 :PRINT' 'lBi(l£H(FSI/3--i +]) tions were plausible when the tune gen· AN END TO DOT AND SQUARE order of magnitude (hundreds, thousands, 431 t£XT I eration was to be done by hand, today TEDIUM etc.) is appended to the right of the .41 PRINT F.(XI:OOTO 591 we could do far better. SlilI, the simpli BY ROD HALLEN 4St REM ' FIND n£ mE PlACE VA/.lE city of this scheme is appealing. three-digit translation. The place values 4M H=\',I,l (lEFTI INS.I )) At some time or another, most of us have and orders of magnitudes are stored in 471 IF 11=. Tl£N 41» Twister is a game produced by the had a need to display one or more words a table at Ihe beginning of the program 48. PRINT IJ$(HI;' H.NIJiD '; In the program below, the value of T Milton-Bradley Company. I have seen in large characters, either for exaggerated for later retrieval. 491 R2=VAL(RIGITlUil,l..DI (Nl H)): IF R2<21 TI£H PRINT 1J$(R2n :OOTO Sit determines the duration of each note, it used as an icebreaker at both adults' emphasis, or to enable the display to be 51t It=VAL ("I DI (Jr/t , 2, 1I I :RI=VIl.(RIOOI(NS,lfHl Nt I-21 I :PRINT 11 ("-\) ; ' -' ;IJ$(RI J ; the value of I specifies the C\lrrent state, and ch il dren's parties. Our Twister mat read at some distance_ As an example, an input of -102 11 23789 511 RET\IIN anti the value of N the next note to play. has been gathering dust lately because the .46237 would yield an output of "NEGA 521 RDt ' lI1EAK II.tIEiER IJl INTO IfU.£ AND FRACTlCfW. PARTS The arrays Sand F store the Slate· move seleclor has gOllen warped and Ihe Usually the programmer must sit down TIVE ONE BILLION, TW ENTY -ONE 531 f(JI I = I TO l..DII1I$ 1 transition table with two entries per spinner always stops at the same place. with a piece of graph paper and (very MILLION, ONE HUNDRED TW ENTY 54' IF ItIDI( PI$ , I. I 1=',' m FI=fIIGKTt (f'I$ ,l.EJI(MJ-] I :/tI-:lEFTS(IIS, I-II ;FI .='Y' :X=l.EN IFI I :roTO 561 state. The next stale is selected by ran· essential!) an eraser, and place dots or THREE THOUSAND, SEVEN HUN Sst t£XT I domly selecting either the value of S(I) Why not let your com pUler generale asterisks in appropriate squares so as to DRED EIGHTY NINE AND FORTY 56' IF l.EN(PI$ J>6 Tl£N PRINT 'my! IM.Y b PlACES "TO lEFT (f OCCUW_ ALlJllD' :OOTO211 or 5(1+1) and playing F(I) or F(I+ I), moves for you? The program accompany· form a matrix version of his large-char SIX THOUSAND TWO HUNDRED AND :m IF lEJrUF.I)5 TI£N PRINT 'scmv! Ilt.Y 5 I'lJI:ES TO n£ Rloo (f n£ OCCIIW... AllI)(D':GOTO 2(1 respectively, to get there. A zero value ing this article does just that. Each time acter message. That done, he proceeds 10 T HIRTY -SEVEN HUNDRED THOU of the nole stored in the F array implies the enter key is pressed, a 'lew move 591 PRIHT :[If'IJT'Nt)TI£R 1IIIIfR';KS:IF lEFTlIKld lO'N' liEN ll.S:roTO 211 ast a.S :END code it directly in PRINT statemenls. SANDTHS." '" ""'" that there is to be no change from the pre is displayed. I would expect that Ihe com The whole exercise amounts to a case vious value. puter generated moves are at least as study in tedium.
22 RECREATIONAL COMPUTING MAY·JUNE 1980 23 595 ~1::1 TIt~1!.!-oP - 165 DATA 4, ~4H, san, O. 96, O. Q. 161 ' , 31~D To those of you who have been caught in II would , of course, be possible to store constructed for groups of 13 characters, 600 PIli" 11') ~Ar.\ 0, Bl54, 1584, ~2, lS92. nu, ~. In'~. I~n that sort of situation, the subroutine in each of the 59 keyboard characters as a then pruned at each end for displaying 60S POKR6 _ IT01 115 .,ArA 0 , I~. I), 0, HI12, "2~, o. 12k. 0 this article will seem like the answer to set of 7 row strings, each containing appropriate segments. The compressed 610 SS _ SST( U(R6),R2,80 780 n~T~ I, 116, &2011, 10. 42~9 , UG8, 0, 41~1 , 121 615 'R111T 5$ 7as D~TA n, ~645, n91. H . 9~11. 9398, 11. B9",I~l(,1) a prayer. All you need do is place the 5 characters. Thus, the " H" in our sample charaeters are read directly from the data UO liEn R6 1n DATA 114,10449,1t)44!>, 62. qUI. llSO. 61,8776,10336 string for large·character display in the output would be stored as "s S", "S area in the R4 loop (line 475) each time 62S IF LQI(L$) < 12 TIIP.~ US 195 DATA S4, Ul1. 9198 , U . 9417 , 9~06, 0, 2322 , Q 0, 2l23 , 0 , O. IOU , UU, n, BII
MAY-JUNE 1980 25 " RECREATIONAL COMPUTING -
",..? T...... ~ ..."" SEA SEARCH IN THIS GAME, YOU MUST MANEUv ER YOUR SHIPeS) THROUGH AN IMAGINARY SEA. IN THE SEA ARE ANY NUMBER OF SURVIVORS (YOU CHOOSE HOW MANY). A SURVIVOR IS A PERSON STRANDED IN THE SEA ' ...?, ...... 0...... ; • • ...? n ...,. .., .., e ...... , ON A RAFT. (THEY ARE SIGNIFIED .....T·' ...... ;""" .,..r'II< __ ,o "",T .. __ ..... , c• .,.,'" _ .... '1 BY AN X). TO RESCUE A SURVIVOR, YOU MUST LAND ON THE SPACE HE • IS ON. THIS WILL REMOVE HIM FROM THE BOARD. IF YOU LAND ON THE ISLAND MADE UP OF AS TERISKS (*) OR THE OUTER BOUND ARIES (.), YOU LOSE. YOUR MOVES ARE SHOWN BELOW. ...... ? ... ,..m ':':""" ;,.";'1", .ion.. , 78' TO WIN, yOU MUST RESCUE ..u It ,.,..,. " ..., c ...... "...... ,0" .. ,.:.....:...... ,,; .0 ....cioo.-" :...... :.~ . 4 6 ALL THE SURVIVORS. ..., ...... tTnO • ••• I 2 3 SPEED IS THE NO. OF SPACES ...... _ ..__ """",,orn., YOU WANT TO GO IN A GIVEN • DIRECTION ...... "" ..... "" .... Since we want it to move, we will use a We call subroutine 2000 to draw the car: APPLE variable bias for all X and Y coordinates. The X bias will be named XO and the Y 145 GOSUB 2000: REM DRAW CAR ANIMATION bias will be named YO. All graphic elements of the car will be specified re Line 999 separates the main program lative to screen location XO, YO. Sub from the following subroutine: BY JIM DAY routine 2000 draws the car: 999 END 2000 REM DRAW·CAR SUBROtrflNE Many Apple owners have expressed an 2015 REM DRAW WHEELS OK, so we can draw the car, but how do interest in creating games that involve • 2020 COLOR = 0: REM BLACK we make it move? We use game paddle • c animated graphics, but don't quite 2025 VLlNYO+l.YO+7ATXO o to set the horizontal position of the • know how to begin. Actually it isn't 2030 VLlNYO+l,YO+7ATXO+5 N car, scaling by 5 for better control: > all lhat difficult. So let's take a quick 2035 ~ COLOR'" IS : REM WHITE 2040 HLlNXO,XO+5ATYO+4 look at what's involved in programming 165 XO'" PDL(0)/5 a simple game using animated low 2045 REM DRAW AXLES resolution graphics. 2050 COLOR = 6: REM GRAY 2055 HLlNXO+I ,XO+4ATYO+2 But wait a minute. Now we can move 2060 HLINXO+l,XO+4ATYO+6 the car to a new position, but the old First we have to decide what we want 2065 REM DRAW BODY image is still on the screen. We need '~ to show on the screen. For good anima 2070 COLOR'" I: REM MAGENTA another subroutine to erase it by painting tion it should be something fairly small. 2075 VLlNYO,YO+7ATXO+2 it white: I-----'" , • I I " • • rJ' >< .. Large , complex displays take too long 2080 VLINYO,YO+7ATXO+3 , , . ,. ,- to draw, causing an unacceptably low 2085 RETURN 5000 REM ERASE·CA R SUBROUTINE fli cker rate. We will use a highly simpli· 5005 COLOR = 15 fied racecar as our moving object. The To position the car on the screen, we 5010 F"ORX=XOTOXOi5 shape of this object is shown in Figure I. must initialize XO and VO: 5010 VLlN YO , YO + 1 al X 5020 NEXT X OK, so how do we draw it? 100 XO= 17: YO= 16 5025 RETURN This places the car in *e middle of the screen. To show the wheels as black, we We insert a call to erase the old image will make the background white: before drawing a new one: lOS GR: COLOR'" IS 160 GOSUB 5000: REM ERASE CAR 110 fORY"'OT039 110 GOTO 125: REM DRAW IT AGAIN lis HLlNO,39ATY 120 NEXT Y Well, now we can move the car from The GR command turns on the low side to side. In fact we can move it right resolution graphics mode and clears the off the screen, which draws complaints screen, and the FOR-NEXT LOOP from BASIC. To eliminate this, we add Figure 1. Raceear paints the ~ntiTe screen white. a couple of tests: 26 RECREATIONAL COMPUTING Continued on PK. 49 MAY·JUNE 19SO 27 DIVERSIONS Players take tums choosing pieces and placing them on the board. The first player to create an equilateral triangle with pieces Q!' of the same coJorwins. Here's a short game with the first player the wirmer: Games to Program: DOZO © 1979 by Herbert Kohl BY HERBERT KOHL III this game, Olle of all ongoing series of articles, the player As in the case of Go, the game is played on the intersections of who recognizes piJttems quickly has fhe adVantage. Herb the lines and not in the squares or lriangles. The object of the imliles you to accept the programmillg challenge, rhell send game is to make an equilateral triangle-any equilateral trio ill your programs of tllese game ideas. angle - on the board. He re are some possible triangles. The first two are obvious, but the Wrd and fourth aTe more subtle. Herb and his wife Judith are co-directors of Coastal Ridge Research {llld Educational Cel/ler in PI. Arena, CA. Tile eel/ler The game is for two players. There are pieces offour different It would be interesting to program the ganle, and also to is a non·profit educational orgallizQtioll designed to provide colors; red, blue, white and yellow. All of the pieces belong explore the following questions: both theoretical al/d practical support to people illvo/I'ed in to both players. One of the central ideas in Dozo is that What happens when yo u play with 2 or 3 colors? progressil'e educationQ/ QC~il'ities. - TD players have to become accustomed to playing for the pattem Is the game trivial? that they are trying to create and not for the pieces they What about five? Is it wirmable then? Dow is a game that Japanese Go masters play in order to command. Is there a best way to go about playing that will insure the wann up for serious extended games of Go. It is a short, It takes a little time and practice to think in terms of Dow. first (or second) player a win? elegant game, and one that might be especially fun to program Strategically more time is spent preventing your opponent What happens if you enlarge the board? Or reduce it when for a computer with a color screen. The game is played on a from winning than in aggressively pursuing a victory. The game you play with 3 colors? board in the shape of an equilateral triangle. The grid on the depends upon the quick perception of patterns, and this is Answers to any of these questions plus a copy of a program board looks like this: probably why it is used as a warm-up for Go masters. for the basic game would be appreciated. 180 Ct.S:PRI NT" n, TIE OLD StEll GfI1E ... 110 IN "llffl D CHEPto THIEF ~ t\{£ P FAl.L~, tIN 5t>~ 1Z0 JIfH)(JIWINT A-Z(ll~ A\30l ~" (l(LETE F~ LEVEL t .... TRS·80 : 130 F~I= l TO'!i A,Ll.200 ~TI 140 PP INT WPUT"tQI IRN PUWERS .tf'IX~~ , P IFP<~T0140 15(:/ Ct.S' PRIlWEFt:;H PLfI'fEp STff 28 RECREATIONAL COMPUTING MAY-JUNE 19", 29 - CRYPT ARITHMS Send your solutions to Jack Crehore, BY JACK CREHORE P.O. Box 96, Char/one Court House, Virginia 23921 Devoted Fans! Your eager calling for If two digits multiply each other to a Cross ou t a square immediately when you harder puzzles puts me in a quandary; I two column Product the tens column of determine that no letter will fit its value. mustn 't frustra te the less skilled readers the Product will be either I less, or 2 In this way you keep reducing the range who also enjoy the challenge thai cryptic less, than the smaner Multiplier: 8 - 9 of letter values you need to study. BY DENNIS ALLISON arithmetic offers. I wish I could quote ~72;4 - 6=-24. more extensively from your leiters Novice! Adept! Genius! Computer-er! The range of possibilities in penonal but I must reserve space for ta bulations The addition of onl y 2 digi ts can never Come 10 Class every R C issue! Your score will promote the Lowly, and exalt computers gro ws with each passing and for a little coaching of our Novices bring a carry of more than I to the tens month. Here are five newly announced so they may share more in the fun! column; 3 digits can bri ng I , or 2, but the High! Write me your vote fo r the never 3; three 9s add to only 27. listing of solution Hints! Get credit machines, each with interesting and OUf first fa n letter today is from surely for unique Hints that you contri bute. unique capabilities. All five can honest a Genius. S. R. McENT EE: your letter I know of no greater aid in fast solvi ng Post Graduates, Ph Os, don't laugh at ly claim to be "personal computers," little fellows! Help 'em up! Share your is a gem of content and arrangemen t. than an Is -not Chart. an Elimination yet they differ in price and performance Table. R C 42 Nov./ Dec. '79 p. 23, shows higher learning! The good teacher learns by factor! of 20 or more. One machine Puzzle 7 didn 't trip yOll , a chart of I I by I I squares, wi th digits more than his pupil. is not even user programmable (yet). CHARLES: So! We've caught another o to 9 along the top row, and the te n Each will find its nitch in the market big fan-a computer user who solves letters of a Puzzle listed in len squares Jack Crehore- NINE HEX and will contribute to the sea rch for a without using his PET. A workmanlike down the left edge. truly adequate persoTIQI system. - DA outlay, Charles, your two pages! I would like to have seen your compu ter program. I forswore word keys years ago: they PUZZLE 21 (NOVICE) PU ZZ LE 24 (COHPUTER) demea n math to word-guessing. INTElliVISION Y,BJR,FAT,JUU 8 C W T H J F R N By Ihe way, 10 myriad solicit;lUs pro Mattei Electronics' INTELLIVISION is a posers that I use puzzles furnIShed by J C B, T K Y, K R C B C W T H J F R H video game turned home informatio n others: we would risk lawsuits by copy center. There are two parts to the intel:. right owners despite ou r utmost care. 8 C W T H J F R H livision system - the Master Co mponent Every cryptarithm I have ever submitted T Y R, B C B, K 8 J and the Keyboard Component. The for publication, I have devised entirely B C W T H J F R N by myself, or as the responsible party. Master Component is programmable by When I deviate I 'll notify my fans. They PUZZLE 22 (AOEPT) C C B T B T e T C ROM cartridge and functions as a video send me many puzzles of grea t interest. ga me. A variety of different cartridges M.tut Electronies' raw INT ELLtVtSION tntelligent T.levlsion Y A S F Simple addition for 3rd Grade Kids with are available, including Soccer (licensed hom. comput.r centef' forms . eompt.u symm for f.mily.nuruinm.nt, To start afresh with our Novices in Cryp Computers. by the North American Soccer League). toducation, p.rIOn81 improv8II'I..,t.nd f ln. nci8l m.n. m.nt. tarithm solving, an d for newcomers, I + FHA F Golf (licensed by the Professional Golf repeat t he Hints given to da te. You may Contil/ued on pg. 37 Association) and Skiing (licensed by the obtain the original treatment of any Hint U.S . Ski Team). Twenty different car Analysis, Jack LaLanne's PhySical Con THE SHARP PC- 1210 AND PC · 1211 cited by sending to me a stamped, ad Y R S T T tridges are available for the Master ditioning; Jeanne Dixon Astrology, Dr. dress~d envelo pe with 50¢ in money fo r xerox or other copies of one or two pages PUZZLE 23 (GE NI US) Component. Art Ulene Weight Loss Program, Guitar This machine looks like an overgrown of RC; price fo r additional pages in same K-A AD\le(Tj~It\G Lessons and Music Co mposition, Speed credit -card calculator, but it has a full order, 20¢ per page, 3 pages fo r 50¢. F+R The Mas ter Component is built around Reading, and Conversational French. 55 -key keyboard , a 20-charac ter LCD This is a test, fars ighted, with odd possibil ~Pace a General Instrument 16-bit micro No programming is required. display, and a "beeper" fo r audio output. ities. If you fa vo r the sc heme, commence, (~ + AR R ) processor and can provide a variety of It is programmable in a BASIC with near or com mend it. sound effec ts, three-part harmony. and in Mattei's view, apparently. the essence ly every feature you could want. The allailaBle good color graphics. Input to the Master or home and personal computing is only trung I missed was a random number Most Hints here below appeared in RC Component is via hand-held keypads access to Central Data Banks with the 42 Nov. -Dec. 79. If you will keep in ge nerator; that makes simple games mind all these minor ax ioms, you will _ ( A+ARR ) %,%, Full Page and control paddles. kind of information co nsumers need hard to construct. There is a cassette soon become an Adep t, someday a Inside and want for everyday living - from air interface as well; so programs can be K-A The Master Component may be expanded Genius! Front & Back line schedules to stock exchange infor stored on a conventional recorder. F'+R with a Keyboard Component which uses mation. Future components of this The technology is CMOS; the program Now: Consider each leller (digi t) fo r its - AR K Covers preprogrammed digital cassettes. It fea system will allow telecommunications R and data are maintained even when the counting va lue in the position it occupies ii tures a 60-key typewriter-like keyboard access to data bases, hard-copy and personal computer is turned off. It's in a problem: small value (01234) or large PLEASE SEND and a digital cassette system wi th com speech ' output, and, eventually, pro - AR K slow, but who cares. The human factors (56789). FOR RATE CARD puter controlled fast-forward and tape grammability. are particularly well thought-out. There R search. The Keyboard Component accepts Try to determine whether a digit is is an integnl line-editor which makes preprogrammed cassettes capable of even or odd: (02468) or ( 13579). Advertising Manager Pricing for the Mas ter Component is program entry and modifi cation easy. handling digital and audio outputs as under $300; for the Keyboard Compo People's Computer Company Soft-keys are available to facilitate the well as typed and audio inputs (from a nent, up to $500. Cartridges cost about programming of complex interactive sys Try to discover whether or not there is 1263 El Camino Real , Box E any "carry" from an operation wherein microphone). $3 0. and cassettes under $40, in most tems. It looks like a reasonable machine two or more digits are added, or multi - H F Menlo Park, CA 94025 cases. For more information contact for the intermediate calculations too plied, together. Keep aware that there are (415) 323-3Ill Preprogrammed cassettes available this Mattei ElectrOnics, 5 150 Rosecrans Ave large and too complex to program by only three pairs of digits tha t will mul ti Simplification step-by-step of an ex year include: J. K. Lasser's 1980 Fed nue, Hawthorne, CA 90250. (213) 644- keystrokes on a programmable calculator ply toge ther and give a Produ ct all in pression in Cube Root. eral Income Tax Preparation, Stock 0411. but not requiring a large machine. one leiter: 2-3;2- 4 ;3-3. 30 RE CREATIONAL COMPUTING MAY-JUNE 1980 31 All in all this is a nice system even though SUlln~ The BASIC itself supports strings as a bit on the expensive side. See the lune Rodrlgutz, a data type (in the fashion of Micro issue of Dr. Dobb's Journal for a review Dr. Dobb', soft BASIC) and integer variables of of the machine. For more infonnation JOCJm~ any length. contact Inquiries Manager, Hewlett-Pack editor, ard Company, 1507 Page Mill Road, using the We've not yet seen this machine. (This Palo Alto, CA 94304, (415) 856- 1501. Tho description is made up from press releas Hp·85 ....PC-1210 '" es.) We're looking forward to seeing is. THE PERO MACHINE to c::omput. the machine itself and to browsing con.... ni.nt .... through the l30-page BASIC manual Int"!lrtted nMluetion •. which comes with it. The PERQ was inspired by the Xerox IVstern PARC Alto Computer. The internals dHigned For more information contact Sinclair are different but the idea is the same. for usct by Research Ltd., 6 King's Parade, Cam It's an attempt to place a substantial profnsion&ls. bridge CB2 ISN, England. amount of computing power into the hands of the user. It's much, much THE HEWLETT -PACKARD HP·85 more powerful than machines like the TRS-80, PET, or Apple. Each PERQ The HP-85 is a very nice stand·alone has a quarter megabyte of memory For the PC-1210, program storage is The display is the usual interface to a BASIC-language computer system. HP and twelve megabytes of disk storage. 400 steps of program and SO memory TV. However, in the interests of cutting calls it "a personal computer for Profes The instruction execution speed is about cells. For the PC-1211, there can be costs, the microprocessor also serves sionals." Its price is $3250 for the basic one million per second, .several times 1424 steps of program and 178 memory as the character generator causing the unit, including typewriter-like standard faster than any of the usual personal cells. A 400-step program is fairly long. screen t'o flicker when a key is depressed. size keyboard, CRT display with graphics computers. In addition, the PERQ is The BASIC statement A cassette interface is included which capability, integral printer with graphics presumed to be part of a group of ma allows programs to be stored on a con capability, tape cartridge and 16K bytes chines sharing common peripherals; a co 10 X=Y ventional audio cassette. A printer inter of memory. This makes it truly competi' axial network system with a transfer face and an inexpensive modem for tive in the market. An optional additional rate of about ten million bits per second leaves 394 steps and 49 memories. telecommunications access are still to 16K bytes of memory is available for aUows data to be interchanged rapidly. come. The nonnal machine comes with $395. The packaging is traditional HP One can select neatly from a menu, The processor with 256K memory, disk, The price is $125 for the PC-1210 and IK RAM for program and data storage; quality, small in size (16 x 18 x 20 An 8 · ~ x II bit-mapped screen with draw pictures. indicate text to an editor, display, keyboard, pOinter, speech out $180 for the PC-I2I1. The computer is this is expandable with an optional inches) and light in weight (under 20 768 x 1024 point resolution refreshed at or whatever. put, RS-232 and IEEE·488 bus inter currently available only in Japan; its memory expansion board to a total of pounds). 60 Hz provides a good-looking graphic faces costs $20,000 and up. A full blown introduction into the US is expected 4K bytes. and text display. The resolution is ade The processor itself executes P-code, system will run about $32,000. For sometime next year. The BASIC language is a superset of the quate to allow display of a single page the PASCAL intermediate ronn. The more information contact Three Rivers The BASIC interpreter, the operating sys ANSI standard with many desirable ex with near typewriter resolution. machine is, or course, intended to be Computer, 160 North Craig Street, SINCLAIR RESEARCH ZX80 tem, character generator, and monitor tensions. An important feature is the programmed entirely in PASCAL. A 32- Pittsburgh, PA 15213. are aU packed into a single 32K read built-in interactive gralprucs available A touch tablet allows one to use one's bit segmented virtual address space allows The Sinclair ZX80 is a new entrant into only memory. The BASIC appears to be both on the screen and ·on the printer finger to enter graphical infonnation. efficient execution of large programs. the personal computer market from a powerful one with a number of unusual too. The keyboard provides a numeric The position of the finger on the table In addition there is a speech output Britain. Developed by Clive Sinclair, features. In particular, language key keypad, soft-keys available to the pro is mirrored by a cursor on the screen. system to allow audible cues. the inventor of the world's first pocket words are entered with a single keystroke grammer, and display!edit/system-con. TV and pocket calculator, the ZX80 since the machine accepts only syntac trol keys which permit direct user opera is among the smaUest and least expensive ticaUy correct statements. Each line is tion of the machine. The 5-inch CRT of the personal computers. It measures syntax checked as it is entered, and it is display can display up to 16 lines of 32 a mere 9 x 7 x 2 inches and weighs only incorporated into the program only when characters. There is a 64-line scroll 12 oz. The cost in Britain (it's not yet it parses correctly. Internally the BASIC memory which remembers up to 64 lines available in the US) is £ 99 .95 assembled, is stored in an encoded form which of data which can be viewed by rolling £ 77.95 in kit form; that translates to Sinclair claims gives them a 4: I space the display up or down. In graphics about $220 US assembled, $176 in kit. advantage over storing the text directly. mode, the screen is an array of 256 X 192 The power supply is a separate module points to aUow for very high resolution available for about $20 extra. One may graphics. The graphics display has its own expect modems at $60 and floppy disks frame memory so the user can switch at $300. freely back and forth from the graphical data display to alphabetic display and The computer is fairly traditional, in the vice versa. The integral printer prints two I style of the PET, Apple and Atari. The 32-character lines per second. The CPU is a Nippon Electric (NEC) Z80. character set supported is the fuU 128 The keyboard is of the touch-sensitive character ASCn set with the added fea type with a standard typewriter con ture that all characters can be underlined. figuration. The keyboard is not fuU Graphic displays can also be output on the size, a matter which will cause substan printer. When plotting, the display is tial aggravation. Video output is organ rotated by 90 0 to allow for the genera ized into 24 lines of 32 characters each. tion of strip charts. The integral tape In addition to the alphabetic character drive uses HP data cartridges which have a set, there is a set of 24 high-resolution capacity of over 200,000 bytes. Read! graphics characters. The standard display write speed is 10ips with a search speed is white on black with reverse-video Sincl.ir Research'. ZX80 It. low·COIt of 6Oips. A directory and named file possible for any individual character. BASIC·llnlJU'~ p ...IOn.1 comput.r. structure for tape-files is standard. Th. PERQ machine proyidH substantial mass storago, •••••••• high SPeed processor, I PASCAL progr.mmingllnYironment, and a high resolution bit·m.pped display. •••••••• 32 RECREATIONAL COMPUTING MAY·JUNE 1980 " show that hobbies, games. and bus.iness systems each, and include supporting Word processing. S6,200 to teach stu are the primary reasons among club hardware, software, and some cash dents microcomputer-based word pro members for interest in microcomputers. awards. cessing systems to LeRoy Finkel, Menlo Park, California. COMMENT ARIES The Club's journal, Micon Circular, is The twenty-one grants awarded are published eleven limes a year. For the as follows: Art education. S7,I19 to develop i first four years there was no English I microcomputer applications in art vers.ion; however, beginning in 1980 General Edueation education to Dr. Beverly J. Jones, there will be an English summary of University of Oregon. each issue. If you want to obtain a sum Mathematics. S9 ,410 to promote in mary of Micon Circular, contact: tuitive understanding of fractions and Statistics. S4,957 10 develop instruc decimals at the elementary school level tion materials in college statistics. WHY I DIDN'T BUY ANYTHING Japan Microcomputer Club to Dr. Rex Thomas, Iowa State California State University at Chico. c/o Japan Electronic Industry University at Ames. A T THE COMPUTER F AIRE Development Association In/ormation gathering. $6,537 for 3-5-8. Shibakoen, MinalO -ku English. S8,583 for microcomputer teaching college students the use of Tokyo !OS Japan. programs that teach recognition of let library reference materials and data ters and words to Roland J. Cross, banks to Dr. Brenda Branyan, Utah BY DAVE GOMBERG Gill University would have been a close In addition to publishing this journal, Oregon School District, Oregon, Wis State University. runner-up. VM/370 costs about $I 75 the Club also holds seminars for begin consin. I consider myself a computer hobbyist per monill. For language processors, INTANGIBLES ners, conducts an annual meeting and Music ed!4cation. S8.856 to develop as well as a computer professional. I I would choose those from the Univers microcomputer contest, and provides an Business and economics. S5,0 17 for CA l in ear training at the North Texas ha ve watched the hobby computer fi eld ity of Waterloo; FORTRAN, COBOL, When comparing micros and medium information service. microcomputer college courses to State University's School of Music develop for several years and hoped that BASIC, and PASCAL cost between priced IBM computers, it is difficult Dr. Wilbur F. Pillsbury, Knox College, to Dr. Rosemary Killam. Ihis time I would find something to coax S50- 100 per month each. Statistical to put a doUar value on certain benefits The Japan Microcomputer Club would GalesbUrg, Illinois. the bucks out of my pocket. I wanted packages would include SPSS, SCSS, each has. The micro does not suffer from like to interact with American clubs and Home economics. S2,605 for nutri substantial disk (say 10+ Mb). some and SAS at about SIOO per month each. I contention by other users, transfers to would appreciate hearing from interested Chemisrry. S4,533 for the develop tious meal planning to Dr. Cheryl dismountable medium of exchange (say would probably have added SPEAK EASY its display at a much higher data rate than parties. A beginning in exchange took ment of computer-assisted instruc Hausafus, IOwa State University. floppies), and a backup for my big at SI50 per month as well, as it is a very would usually be used in dial-up opera place at the Computer Faire in San tion (CAl) graphics for chemist!')' disk to tape or whatever. I expected to productive language. My software bill tion, and has predictable program execu Francisco where Professor Toshiaki classes to Dr. M. Lynn James, the Medical Educafion and Training provide my own keyboard/display and would then have been less than S I 0 per tion times. On the other hand, the vol Yasuda of the School of Telecommunica University of Northern Colorado. printer. user per month, or, say, S500 capi ume of software available for IBM 360/ tion Engineering, Tokyo Denki Univers Hand-eye coordillatioll. S4,445 to de talized. 370 systems is prodigious, the value ity, met many interested Americans. Chemisrry. S5,855 for the develop velop a hand-eye coordination diagno HARDWARE of natural data-sharing with s.imilar ment of computer-based programmed sis and training system to Dr. Jerry Ward, Education Services Management THE PACKAGE users is difficult to measure, and the instruction modules to Dr. Gordon Part of what I do for a living is to con' convenience and savings of buying and M. Barrow, Milne Press, Carmel Corporation, Research Triangle Park, figure medium-sized IBM systems. If North Carolina. For about S2900, I could buy ave!')' maintaining a single copy of software APPLE Valley, California. I wanted to support 100 such users, I nice setup from IB M (I/IOOthth share) is hard to quantify. These must still be would buy: counted as intangible IBM benefits. Diabetics a"d "ursillg. S6,538 to -so I set out to the FIFTH FAIRE EDUCATION Bilingual education. S4,898 to de teach diabetic care skills to nUfsing looking for a competitive micro system. monstrate the effectiveness of CAl IBM 4331 (1Mb CPU) CONCLUSIONS students in instruction tutorial/simula 3370A +8 (I 100+ Mb disks) in bilingual education, to the Stanford tion format to Dean Charles Sorenson, MICROS FOUNDATION Avenue School in the Los Angeles 8809 tape drive I'll be back at the FAIRE next year, Grand VaJtey State College Allendale, 3278 printer Unified School District. Michigan. Total S You can guess the result. A system like still looking, but it will be two or thee AWARDS years at least before I can be lured away this, ignoring software deficiencies, costs Administrative. S3,859 to develop Arti/icial speech. $9,637 to develop If, in addition, I wanted to support a from the Immense Blue Mother. between $6-!OK bought as a micro diagnostic student records for junior lot of remote usage (dial-up), I would programs that enable speech-impaired computer. Th e main stumbling block 21 Gran ts for the Developmen t high schools, to Dr. William H. Robin children and allow children, lacking add: seems to be the still very high unit cost of Microcomputer-aided Learning son, Marshalltown, Iowa, Community manual control, to learn arithmetic. of mass storage (disks). Even at OEM Schools. IBM 3704 communications controller 30,000 prices, S3 -4000 seems to be the rule. JAPAN MICRO Prentice modems 10,000 Medical problem soM,,!. S5,239 to The backup si tuation is still in ilS infancy; CU PERTINO, CA-March 17, 1980- Computer literacy. S8,605 for pro develop a system to teach medica l Pacific Telephone lines (capitalized) 10,000 we can probably hope for progress COMPUTER The Apple Education Foundation today grams to familiarize people with problem solving techniques in simu Grand total S 233,000 there. But the fact is that until Winchest announced the award of over S120,000 computers to James W. Garson, lated patient encounters to Dr. William er drives (or some functional equivalent) worth of microcomputer equipment for University of Notre Dame. Schwartz, Children's Hospital, Phila The first configuration would support 16 drop in end-user price to about S I500 CLUB local and 8 dial-up users concurrently; the development of ge neral and medical delphia, Department of Obstetrics. with backup capability, it is going to be education materials using microcom Casll management. S6,335 for cash the second would support 16 local and very tough to beat IBM's price/perform 32 dial-up users. The practical limit puters. management/investment programs to "Our continuing goal is to place com ance. If IBM improves similarly in that of this machine is between 20 and 40 con Dr. John M. Whitmer, Iowa State puters in the hands of people who can time, the micros may never catch up. current users. Thus the hardware from The foundation awards provide twenty University. develop innovative learning techniques IBM would cost about S2400 each for three microcomputer systems valued at and who can demonstrate their effective This is not to say that micros are not 100 users. This is major pricing break over S I 20,000, in support of education Elementary ed!4cation. $2.260 for a ness," said G. Gregory Smith, the Apple fU n, or even that they don't have valid through for IBM gear and represents projects ranging from preschool through CAl "life skills" curriculum by Education Foundation's executive di applications. But I do claim that as a substantial decrease over what sucll a college, medical education, and training. Margaret Cole, Bowditch Middle rector. personal, general-purpose computers they They are a part of the foundation's School, Foster City, California. configuration would have cost three are very expensive. They generally do years ago. The Japan Microcomputer Club, estab long-range efforts to support opportuni provide better price/performance in the lished in 1976, is the largest microcom ties in education through the use of ex Elementary education. S5,085 for For grant applications, address enquiries SO FTWA RE area of CPU cycles, but when I configure puter club in Japan. Its membership of panding microcomputer technology. the development of CAl to learn to: The Apple Education Foundation a micro, the CPU costs much less than about 3,000 covers an age range of 5 basic skills using consumer applica 20605 Lazaneo Drive For an operating system I would have each of the floppy drive, hard disk to 74 years. Students and engineers The foundation's current series of grants tions to Willis Ann Corcoran, Omaha, CUpertino, CA 95014 chosen VM/370-CMS. MUSIC from Mc- drive, and hard disk backup. are prominently represented. Reports provide one to three Apple II computer Nebraska. 34 RECREATIONAL COMPUTING MAY·JUNE 1980 35 - PUTER publication, COlllact, No.5. (For I believe that this will tend to promote range. The middle colors of the spectrum this example, the symbol " @" means exclusive use of a small TV set as video are generally easier on the eyes. "Programs from Cursor issue I through COIlfinlled from pg. 30 12" - graded by Ma rlene Pratto. EDITING "control D".) display for the computer, thus adding a Problem 21: hidden e xpe ns~ . Also be aware that if any image is left Y 5 PR INT " @ OPEN X" on the display for too long it may tend Hints: Column 10: disappears! So it • must be digit J borrowed by Column 9. SOFTAPE POKE 33,33 : PRINT " @ What about the TV itself'? Which kind to 'burn' the video tube at that point. G ..... Proanm ~~ u I .. II, WRITE X": LIST : ..... ~ '-' ~ , Col. 7: R - B = R. B acts like 0 (zero), is better? An in·line picture tube is a As an IBM 3033 computer operator, I "' but you will need proof that it isn't 9, PRINT " @ CLOSE": preferable feature of most sets now, can testify to that. Our screens have ,., WANDER , PREFIX END • · due to carries. If your computer has color output many burned-in images. Color TV ""FACE , · Cols. 10 and 9: YB - J'=T. If B were 9 (Apple, Atari, OSI, etc.), you may hook PAPER , · By entering the command RUN 5, the sets can be ruined if the screen gets , it WOUldn't be borrowing I (Y) from PROGRAMS it to either a black and white or color · Column 10. So B is 0 (zero)! program will open a file called "X" and burned spots. Thus, don't allow the same CANYON"'" · set. With black and white, the colors FLIGHT · Co .. 4: T - Y (I) '= B(zero,O). So T must LIST the BAS IC program into the file. thing to be displayed for too long. " become shades of gray. Since you will " · be 2, but has lent J to Column 3. By using the command EXEC X, the H All of l bo... have to read small alphanumerics, make One other consideration when using a IIRICK , . BY DDNALD R. DPEDAL BASIC program can be loaded back into SHARK , sure the set has a high resolution. This is TV for your video display is the radio · Now that you know that B is 0; that Y memory as if it had been typed in or , · · is I; that T is 2; you gel J from Col. 9; one area where a color monitor is general· ation factor. I have not found any reo w , · · My programming is usually a "trial and LOADed. "",m, , then C from Co1.8; then U from Col. I; ly better than a standard TV set. Also a search on this area yet, but I believe · · error" procedure, I like to try different FLASH , · then Rand K from Cots. 2 and 3. In Col. black matrix type screen is preferable that sitting 100 close to a TV for any HMAN , · methods of producing the same results, BASIC Programs that use a SOFTAPE SHOOT , 9, you see YB less J leaves T. So J must since it gives a clearer image. Different length of time may be bad due to minute · change formals and experiment with my prefix program must begin with line O. , · be 8 to make it: 10 - 8=2. Col. 4 manufacturers refer to this feature in radiation given off by the set. '"YAHTZEE , · lent 1 Col. 3, so that J is really 18, program. This usually requires rewriting By making line 0 = GOTO 10, the above COURSE different ways, each with a patent on · so the two Ks are 9s. the program severa! times as one version program can be entered at line 5 and can " · · their particular method. Matrixes of As a final note, Commodore should be ... All "rlbo.. is replaced by another. It is a matter of be used at any time to save the BASIC , black lines, offset columns of black co mmended for switching from a black , OK! You finish! You've got it made convenience, if not a necessity, to be able program. ."'" , · already! rectangles, or black outlined dots - all and white to a grren phosphor built· GUESS , · to save different versions or the final in monitor. AT A RI can be commended QUIX · · The user now has the luxury of loading are preferable to a standard set. HANOI , · Problem 22: version at the end of a session and to for their screen protection feature. If IISHIP , · · be able to fun them again when desired, and running several different programs the computer is not accessed for 7 MIND , • Hints: Three letters identify themselves. Also remember that the smaller the FBALL , · appended to the same prefix program Shuffle digits to fit the rest! Too easy? screen the sharper the image, since the minutes, it begins changing the color REVERS , · SOFTAPE (10432 Burbank Blvd., North without having to load and append the registers for the screen display every few DEMON · dots are closer together. Thus 9·inch WIPEOllT Problem 23: Hollywood, CA 9 1601) has developed prefix to each one. This allows for faster seconds. The information displayed re " · • to 13-inch screens make better video STATES " Hint: Only that the root is evident. several programs which make use of editing and trial of different versions P1CKUI' " · displays. mains the same, just the colors change. · 6502 machine code. The machine lan and allows a given program to be modi Dark colors change to light etc. This ,., All of tbe abo... " Problem 24; guage programs, referred to as "prefix" fied by adding new lines to it from disk. , Video displays are naturally hard on evens out the total exposure on the , · · Hint: Columns 5, 6 , 8 and 9 are logical programs, are disguised as INTEGER your eyes, but there are many ways screen and helps prevent images from be ""''" . · keys, BASIC programs for easy LOADing and to ease this eye strain. First, keep the ing burned into the screen. ."MAZE •, · TITRATE · SA VEing, The prefix programs are then contrast down. Bright nigh·contrast letters .eo " · · • appended to a BASIC program and HOME VIDEO on your screen are bad for your eyes Send your comments to Len Lindsay, " A SIMP LE TRS·80 CALLed when needed. 1929 Northport Drive, Room 6, Madison, Roprin' by ponnls/.ton of Co"'P~ '" loI o.ul»o. P.O. Do. 5119, SEARCH MODULE REVISITED since they must adjust to the two ex· 0 ...... 1>0"', NC 11.IIJ, Cl ,919. S",-,U Sy"om Sorn.,.., Ino. DISPLAYS · tremes so close together. Try to have WI 53704. Include a self·addressed 11.."", 1»"1 form prolllbj,od. As a general rule, once the prefix pro your room lighting about the same STAMPED envelope if you expect a In the March/ April issue of Recreational gram has been attached to the user's brightness as your video display (never reply. Computing Ramon Zamora published a BASIC program, the combination can tutorial article and a computeri zed BY LEN LINDSAY turn off the lights when using your com no longer be edited a,nd SA VEed. How puter). If your screen is brighter than directory search program for the TRS-80. ever, for the disk user this is not com· your surroundings, your eyes must CORRECTlDN Unfortunately the listing which appeared pletely true. Almost all home computers use a video continually strain to adjust to this dif CURSOR had many many typographical errors. We display of one type or another. This is ference. The article "See What You Hear apologize for any inconvenience it may The normal use of SOFT APE prefix a major advance from slow teletype PROGRAMS and Hear What You See" which have caused our readers, It is printed here programs allows writing the BASIC output. Some computers come with a The type of room lighting and its place appeared on pages 42-44 of Re in corrected form. program into memory, appending the built-in monitor while others leave that ment are also very important. Fluorescent creafional Computing (Jan-Feb GRADED FOR " .tN·· """"""'UDD'''.not. Su.~ " prefix program, and then SA VEing option to you. I would like to present lighting is best if it is diffused and re 1980) included excerpts reprinted, .. DIM ~ " ,'OI. N ''' ' OI. ~ '' ''OI.~''' , ...... "o.. ..nOl.'','''. n"" .. c ... 'N ""'""N "" "'''''''' ' ~''tN' -,D.~.(>$~ ' I"" them as a single program. Once the pro a perspective on video displays. Though flected from the ceiling. This gives Afari .. cu ... ,,.., -row"""IZ'DD" 'cwo..· by permission, from Basic, .. '.'",mo.'''''''''.. _""1 gram is run, the prefix program is no not an expert on the subject, I did try even light to the room and reduces the CLASSROOM by Bob Albrecht, leRoy Finkel, .. "nn .',...... ' OO ''''' .. AI 36 RECREATIONAL COMPUTING MAY·JUNE 1980 37 Cbnti1!lIed Irom pg. 7 2600 B.C. Many conceptual and mechanical developments, including the perfection of sequence-control mechanisms in automatic music systems, preceded Pascal's development of a mechanical adder and subtracter called the Pascaline, in 1642. In 1694, Leibniz introduced a device that could also multiply and divide, a great advance. Babbage is the person who is usually cited as the originator of the modern concept of a computer with memory, for Babbage's Analytical Engine embodied a srore as well as a calculating mill. Goldstine notes that: "It is interesting to note that Babbage thought instinctively in tenns of the prime technology of his time: the steam engine." [20, p. II) Even if Babbage did conceive of a steam -driven automaton 185 years after the musician Kirchner, Figure 7. A Classic 1960's vintage Moog synthesizer, model and even if Babbage did hate music [ 21, p. 3 I, he must II Ip, with keyboard. be given some credit in a computer music history. The pro· grammable Jacquard loom spawned a number of instruments based around punched tape, including the mechanical piano Some other devices involving electromechanical technology developed by Racca in 1886 [Figure 10). With the intro· were devised in the 60's for controlling analog synthesizers duction of Hollerith punch·code machines and the forma· and audio equipment. These include Hugh La Caine's Homo tion of IBM, sequence-control devices had, in the 1920's, graph, in which six channels of control-voltage infonnation neatly reached their apex. could be stored on a (magnetically-sensitive) sprocketed Figurtt 12. The lLUAC digital computer at the Univef$ity of foil tape. Le Caine also developed a voltage-controlled tape The real apex of sequence-control.type mechanisms was the Illinois, '959 with composer Lejaren Hiller at right. (Photo: recorder system, which is still installed in the Electronic Music electromechanical calculator, the Harvard·IBM Mark 1, in Figure 10. An example of a mechanical piano using a form of Myron Davis, from Computf/rs and Computation ('971) W. H. Studio at the University of Toronto. In 1967, the composer operation in 1939. This device used relay technology (as did punched paper tape technology similar to the Jacquard Loom. Freeman, San Francisco) Emmanuel Ghent introduced a device called the Coordinome the RCA Mark I Sound Synthesizer of 1955) to perform pre The lever behind the playing handle controls the dynamic which allowed for programmable (punched paper-tape) patched calculations. The first electronic computer was the level. control of Moog Synthesizer modules. Eniac, [Figure 11) initially run in 1945, but it did not incor In 1957, at Bell Laboratories in New Jersey, some recent IBM porate the concept of the stored·program which is associated computers had been delivered to the Behavioural Re·search Despite these advances in programmable or non-programmable with computers today (22). The design of an all-electronic Lab, and a project began there to generate sound from the sequencers for analog equipment, by 1969 computer stored'program computer, the Edvac was developed in 1944 computer (both speech and musical sound) for various psycho technology had made great strides in music applications. Max by Eckert, Mauchly, Goldstine, and Von Neumann (20, logical and acoustical experiments [25}. It is interesting to Mathews' book The Technology of Compurer MUsic [12) was p. 184·203) and [221. However, the machine was not actually note that the first fragment of music with computer-generated a signal event that indicated the direction of the future. built until 1950. In the meantime, the transistor had been sound In the Silver Scale (1957) by N. Guttman of Bell Labs, invented at Bell Labs (I948) and core memory had been was an original piece in just intonation (a temperament based Computer Origins conceived by Jay Forrester of the Whirlwind computer project on integer·ratio intervals between tones). The fragment was at M. I. T. in 1947 [20, p. 310). In 1949, a group at Cambridge generated using Max Mathews' MUSIC I program for the IBM The history of computing devices parallels the history of University in England introduced the Edsac computer [231, in 704 computer. automatic music devices. The main events start from the which both instructions and data resided in a common store. use of the abacus, the Chinese hand·held calculator, around The present computer age was then underway. MUSIC I could only synthesize one voice of sound, with one wavefonn, and the only wavefonn used in Guttmann's study was the triangle wave \261. In 1958, Mathews and his ·.1 .. . associates introduced the program MUSIC II, which offered ",t: f! '. i!f~ · ;!:; ..... , .. " four independent voices of sound and a choice of sixteen · waveforms stored in memory. No attack or decay envelopes • i' ~ 1 . • • •• • ,,'t . ... ••• for the sounds were provided, though. A major advance came • • ..• with the introduction of the program MUSIC III in 1960, • • Figure 11. The Eniac, the fif$t electronic computer, built which included the important unit generator concept. Unit generators are the building blocks of most computer sound .... ~'"1 ... V" •,tf t~ ...... at the University of Pennsylvania in 1944·45. II contained ...... """. ... • 19,000 vacuum tubes and consumed 200,000 kilowatts of synthesis programs today. Each unit generator is a signal· ~ • • • • • • powur. (Photo from Computers 8fld Computation ('971) processing module. By com bitting unit generators into specific .- W. H. Freeman, San Francisco). interconnections (similar to the "patches" associated with . • •,. analog synthesizers) one can create digital instruments and • ultimately entire digital orchestras. In 1962, Mathews and his Computer Music Beginnings associates produced the sound synthesis program MUSIC IV, variants of which are still in use today. MUSIC IV offered in 1955, Lejaren Hiller and Leonard Isaacson, then at the better computational facilities including a macroassembler University of Illinois, began their famous experiments with especially developed (or the music project; MUSIC IV ran computer music composition. Their project involved the originally on the IBM 7094 computer. A machine-independent computer generation of score data; the scores were then version of essentially the same program was later developed, realized by traditional instrumental means. Central to this written in Fortran, and called MUSIC V (12). Since its intro work was the notion of music as an algorithmic process. This duction in 1969, MUSIC V has been a standard tool for was not the first attempt at "algorithmic composition" (cl. computer music, implemented on everything from large, dual below) but it was the first known attempt at computer processor Burroughs 86700 systems (48-bit word) to the PDP assisted composition [241. Hiller's ILLIA C Suite was first II minicomputer (I6-bit word). perfonned August 9, 1956, in Urbana. A less ambitious project around the same time was heralded in the New York The earliest use of computers for musicological purposes is Times as follows: "Brain Computes New. Tune for TV." That reportedly Bernard H. Bronson's use of an " IBM " for handling news item discussed M. Klein and D. Bolitho's work on the "large masses" of quantitative data on folk tunes {21, p. 151. Figure 8. A Buchla Electronic Music System, series 100. Notice the three sequencer modules for genereting present sequences of control tune Push ·Button Bertha using a Burroughs Daratron A problem with this reference is that IBM did not make an voltages (top of lower cabinets). computer. electronic digital computer until 1953, with the introduction 38 RECREATIONAL COMPUTING MAY·JUNE 1980 39 of its Model 701! One can only assume that Bronson actually he and Jeffrey Mack developed their successful Hybrid IV worked with a machine such as IBM's SECC (a sequence system around a small PDP -II minicomputer. [15] The KHz it is necessary to produce 20,000 samples for each second controlled, relay and tube calculator installed at IBM World system was portable, and concerts in the United States and of sound. Clearly, computer music is a computationally Headquarters in New York from 1948 to 1952) or some other Europe were perfonned.IFigure 9] Other early experimenters intensive application. While the ear can hear up to 20 KHz, digital bit stream analog voltage electromechanical monstrosity. with hybrid systems include Max Mathews and F.R. Moore often computer music systems work with more restricted 1 speaker and their Groove systems at Bell Labs. One interesting feature bandwidth for purely economic reasons. Higher-speed ( The first reported use of "music transcription by computer" of their approach is that it was based on graphics techniques computers cost more than lower-speed ones, and to store a oomputer . (J 957) involved entering notes into a computer memory [161. Hybrid systems were also developed at Toronto, by wide-bandwidth audio signal can take enonnous quantities of DAC~Jl] amplifier via a code language. The codes were entered on punched cards Gabura and Ciamaga [171 , at Yale, by David Friend of ARP disk space. '------'H read into the machine; routines were written for "automatic [lSI, and at EMS, Stockholm, as described by Wiggen (1 91. transposition and printing" (in alphanumeric notation) of the Sound quality in computer music also depends on the sample resulting musical fragments (271. Modem developments in computer music (since 1970) are too width, or number of bits used to represent each sample. As a Figura 13. A (:omputer interfaced to a DAC, amplifier, and numerous to survey in this short article. Back issues of rule of thumb, one obtains six db (decibels) of signal-to-noise speaker for sound generation. Hybrid (AnaJog/Digita1) Sound Synthesizers Computer Music Journal, the Journal of the Audio Engineer (s/n) ratio for every bit in a sample. For example, with 8 -bit ing Society, and Interface are all valuable source of informa samples (fed through S-bit DACs) one can o btain a signal to In the late 1960's, a number of systems were built by inter tion on developments of the J 970's in computer music. At this noise ratio of 4Sdb, which is really not too good by today's facing a minicomputer (a small computer costing less than juncture, a closer look at the fundamentals of digital sound audio standards. In fact, it's pretty poor. Sounds produced by $5000) to an analog sound synthesizer. The computer gener synthesis is in order. 8-bit DACs have a very audible hiss and lots of harmonic ated signals which were converted into analog fonn by a distortion. So what then is the phenomenal "digital sound" digital-to-analog converter (DAC). Each voltage-controllable FundamentaJ Principles of Digital Sound Synthesis that some record manufacturers have been touting so heavily? input of a synthesizer was hooked up to a DAC ; since control Very high precision audio systems may be built using 16 or values voltages do not vary rapidly (anyone musical parameter rarely First, music takes electronic fonn as a changing voltage in a more bits of sample accuracy. For example, one commercially changes more than 100 times per second) the minicomputers wire; this is how speakers in stereo systems are driven. A available digital sound synthesizer uses 20-bit samples had little trouble keeping up with the music. positive voltage pushes a speaker cone forward, and a negative internally, which results in around a 120 db sin ratio D ~ ______~ voltage will pull that cone inward. If the voltage varies fast virtually beyond the ear's discrimination. Even this manu The basic idea behind digital control of analog sound syn enough, the speaker cone is vibrating at an audio rate; the air facturer uses 16-bit DACs though, for economic reasons; o 1023 thesizers (voltage-controlled synthesizers) is that the computer around the speaker is vibrated, and we hear sound (vibrating DACs of greater preCision are not economically justified. If array'" indices is a repository for tables of functions, which are initiated at air). Through a device called a digital-fo-analog converter (or one is on a strict budget, good 12-bit DACs will suffice pretty specific time-points. In addition, the "patching" of modules DAC) it is possible to change bit streams sent out by a com well. to one another may be automated, and similarly linked to a puter (through one of its input/output ports) into a varying Figura 14. A triangle wwaform, stored in a (:omputer array. sequence of time-points. An inexpensive PDP-8 (12-bit) voltage of the kind that pushes speaker cones around (Figure To generate sound from a computer the most common system was the core of the MUSYS hybrid system at EMS, 131. These bit streams are generated in units called samples. A method is to scan a wavetable. In this technique, one simply London, developed by Peter Grogono and Peter Zinovieff sample is like a time-slice of a music signal. Sampling theory stores a waveform (say a triangle wave [Figure 141) in an grap"ic$ (1 3,14). Ed Kobrin, at the University of Illinois, also built tells us that in order to represent a sound signal with array. We then scan the values in the array, sending each one in terminal a hybrid system, called Hybrid fl, based around a PDP-S. frequencies up to n Hertz (or cycles-per-second) it is neces turn to a disk me in which samples are stored. (See the listing Later, at the Center for Music Experiment at UCSD (La Jolla) sary to generate 2n samples. Thus, to generate a signal of 10 below in Pascal.) program sound (store); "" type index = (0 . .1023); {sample table length} >¢==:====::::::J ,,", samples = f-32768 .. 32767); {1 6-bit DAC} tablet wavetable = array [index] of samples; va< triangle: wavetable; sine: wavetable; store: me of samples; procedure fill table (tablename : wavetable); begin Figura 15. A mi(:rocomputer configuration for stand·alone {this procedure fills each wavetable digital music synthesis. with characteristic values} end Typically another program is written which gets the central procedure generate (tablename: wavetable); processing unit (CPU) of the computer to fetch samples from the disk file storage and put them into a reserved block o f begin {generate} memory (e.g. , block A). At the same time this program activates a direct-me:mory-access (DMA) device which waits "" i, j : index; until block A is filled , then it starts fetching samples from begin {one second of sound at 40 KHz} block A and send them to the DAC, one-by-one, in a smooth fori: = Oto 39 do manner. When block A is all consumed, then it fetches fr om for j ; :: 0 to 1023 do block B (which has been filled in the meantime by the CPU). write (store, trianfe [j]); This scheme, called double-buffering, is a very common technique for generating (pre-computed) sound from disk end {one second storage. A typical hardware configuration needed to support end {generate} such a system is shown in Figure 15. One can find almost the begin {mainline} same configuration in systems from large IBM and Burroughs fdltable (triangle); Figure 9. Ed Kobrin's Hybrid IV workshop, set up in Berlin. From left·to·right: VT52 CRT Ion table), tele computer-based music installations to microcomputer type, analog sound·generating equipment, PDP-11/10 with dual-(:&Ssette unit (on table). One the walls: some of generator (triangle); systems. There is one very major advantage to this " pure" the 16 speaker units to which sound (:ould be distributed. end {mainline t fonn of computer music. Since all sound-generating instru end. {program" ments are modelled in software, it is fairly easy to add or 40 RECREATIONAL COMPUTING MAY·JUNE 1980 41 ----,-, modify synthesis techniques, or any other music subsystems, problems associated with these boards are fust, their inevitably Amplitude modulation is another useful technique which systems for computer-aided composition. The first category for that matter, such as composing languages, graphics 8-bit sample width (the problems with 8-bit samples were involves simply multiplying the signal by various fUnctions. comprises systems in which the composing program need only systems, or music printing software. pointed out earlier) and the typically 8-bits of frequency Other useful sound synthesis techniques have been developed be initialized - it then proceeds to generate a score. It is still select resolution. As to sample width, more like 12 to 16 bils for time·varying spectra, including granular synthesis [321, up to the composer to select from the output of a composing The disadvantage of pure computer music is first that it is necessary for audio as good as a decent stereo system. The which involves combining thousands of sonic "quanta" to program what he/she wants. This output may then be edited requires fairly large (expensive) capacity disks to store problem of frequency resolution is linked to the fact that with produce spectra, VOSlftf [331, a flexible fonnant synthesis or combined with other elements of a composition. Examples samples. Floppy disks are, for example, inadequate. 100 to an 8-bit frequency select quantity, only 28 or 256 frequencies technique, stochastic synthesis [34], which typically involves of composing programs include Hiller's work with the lLL/AC 300 Megabyte disks are not uncommon at computer music can be obtained. Only a gross (out-of -tune) approximation to using various combinations of stochastic functions as wave SUite, Xenakis' ST program [341, Koenig's Project J anti studios, though a 1.2 Mbyte cartridge disk is satisfactory the standard equal-tempered scale is possible with this low forms, and instruction synthesis {351, which produces wave Project 2 [361. and my own PROCESS/ING program. [Figure for storing about 30 seconds of 16-bit sound samples (at resolution, and alternative scale systems (such as microtones) forms from sequences of virtual machine instructions. 17J [37J The basis of most of these programs is a stochastic a 20 KHz sampling rate). are impossible to obtain. If digital sound synthesis has any or probabilistic process wIDch generates musical events thing to offer, it seems it should go beyond the capabilities Machine Composition according to (often changing) musical constraints. Combina Second, most computers require a great deal of time to of traditional instruments. Since in traditional instruments torial or permutational processes, as well as grammatical compute the millions of samples necessary for sound; (~.g., a piano) we can get timbrally-interesting, polyphonic, Over a century before Lejaren Hiller's pioneering work with processes have also been employed for au tomatic composition. computing ratios of greater than 200-to-1 (200 seconds of real-time, in-Iune synthesis, what is the point of a digital computer composition (1955), a machine for composition computation for I second of sound) can be expected for a instrument with less capability than this? Particularly since was developed by the Dutch genius Dietrich Nicholas Winkel, Computer-aided composition systems cover a broad range of complex sound computation on a small computer. If you can frequency-select resolution is simply a matter of the width of the real inventor of the metronome. In 1821, Winkel implementations. The common denominator of all of them is let the computer cook all night to generate a couple of one register, this kind of cutting comers (hamp·ering musical completed a device called the Componium. This machine that they provide for a significant degree of interaction minutes of sound then this is fine, bu t sometimes real· time expression) is an inexcusible engineering practice. Further, aroused great interest in its time, and achieved some success between the musician and the computer system. It is possible generation can be very useful in realizing a musical idea. most of the budget boards use the very basic wavetable [3, p. 191. Although little is known today about the machine, to work on va rious musical levels with computer-aided compo scanning technique described earlier as their only synthesis it apparently was capable of performing variations on themes. sition. On the one hand, there are low-level music languages Digital Synthesizen technique. Thus, they can only produce a very steril e fixed The basis of the Componium and all of present-day experi such as the Stanford language SCORE and the MIT music waveform sound. An ability to produce time-varying wave ments with computer composition is that music i.J an language MUS/C-ll. While the SCORE language runs on a Digital synthesizers are fast, special-purpose computers whose fornlS is essential for interesting sound synthesis. algorithmic process (i.e., musical progressions obey compo large PDP-IO computer, and the MUSIC-ll language runs on main purpose is generating sound samples for real-time music sitional rules). Of course, these rules are not fixed, and usually any PDP-II (including the LS I-II microcomputer) both are work. Digital synthesizers are fast because they are required to Synthes.is of Time-varying Waveforms each composer relies on his/her own combinations of rules. examples of languages wIDch allow a composer to specify perfonn millions of calculations for sound samples each acoustic events in great detail [38, 391. second. Thus, they are usually designed around high -speed The simple wavetable-scanning algorithm described earlier In "programmed music" (G. M. Koenig's tenn) the composer logic such as Schottky TIL or ECL with lots of parallel pipe is useful for generating a wide variety of stationary spectra, encodes the compositional rules in the fonn of procedures. At a slightly higher level, an interactive composition system lining for added speed. Usually digital synthesizers are i.~., tones whose spectral characteristics do not change over These procedures interact to model some fonn of musical allows one to apply musical procedures to larger units of music controlled by another ("host") computer, which supplies time. To generate the more interesting time-varying fonns of behaviour. As a result of this behaviour, compositions or data, such as entire phrases. An example of such a system is instructions and data required for synthesis. One of the most spectra, a first approach might be to blend a collection of compositional fragments are produced by the procedures. the Structured Sound Synthesis Project (SSSP) system at the advanced digital synthesizers built is the Alles synthesizer at different fixed-waveform sounds into one continuously There are many ways of working with compOsitional pro University of Toronto {401. The group there has made great Bell Labs {Figure 16J. This synthesizer is controlled by an varying sound over some short dUration. Indeed, this is a cedures, and only a few will be surveyed here. strides in implementing computer graphics techniques for LSI-II host computer, which feeds data to the 256 "voices" useful technique, called additive synthesis. One usually starts composition. The "windows and menus" graphics approach to of the device [28J. A system of similar magnitude is the with a collection of sine waves at various frequencies; these are Computer music composition programs can be divided into musician-machine interaction promises to greatly improve Samson Box, designed by Peter Samson of SYstems Concepts mixed at various amplitudes (and sometimes at various phases) two major classes: autonomous composing programs, and the working modes of computer musicians. in San Francisco. Both of these machines produce sound on to fonn complex, time·varying spectra. Theoretically, any the order of the symphonic in complexity, but their price tags sound can be simulated with combinations of sine waves, given State Freq FlIlp Spec Spill Beg. Dur. End SP4C Prox Amp Aalp Den Wav W,lp are over SIOO,OOO. However, many more compact 8 to 64 the data. This principle is the foundation of Fourier analYsis voice instruments are now coming onto the market, based on of signals, and subsequent Fourier synthesis. The main built-in or hook·on microcomputers. problem with Fourier synthesis is that enormous amounts of data (saying which frequency should play when, at what 61 48 25 95 -21 86 . 5831 .24 86 . 8231 12 9 50 96 , -16 amplitude and phase) are required to produce interesting , 43 time-varying spectra. 62 61 _27 81 23 87.3589 .2405 87.5994 11 -9" -9 _5 86 " 16 86.9605 5.2149 92.1754 16 6 37 - 20 100 " -" Subrracrlv~ synrhesis starts from an already complex sound, "64 "68 - 10 99 o 86 . 5386 1.5245 88.0632 20 10 37 _21 11" such as a noise source, and proceeds to mter out selected -" components of the source to obtain a more controlled spec 77 _18 87 -12 86.2160 .2708 86.4868 27 18 27 -23 " 7 _ 27 trum. By varying the ruter coefficients over time, one can " 60 -21 85 _11 86.2347 .3 86.5347 16 17 22 _29 "71 produce richly-varying spectra. The disadvantage of subtrac -" " 64 _15 75 _11 tive synthesis is similar to that of additive synthesis; they 4 92 . 4429 .41 92_8529 99 100 70 _7 94" both require a great deal of data (the driving functions) and "68 100 -12 55 , 92 . 3185 3. 6767 95.9952 98 98 65 - 10 "36 97 -9 they are computationally costly. For this reason, several new 65 _1 51 o 99 . 5983 1.1478 100.7461 97 100 60 _1 36 100 o techniques for digital sound synthesis have been developed ")Q 66 _10 47 o 99 . 5945 90 54 _23 which require much less data: these are called nonlinear .5 100.0945 85 34 94 7 synthesis methods. 71 90 - 15 41 90 100. 3636 1.5108 101.8745 86 62 32 - 27 39 16 64 72 5 o 40 103 . 8533 .8174 The technique of frequency -modularion (fm) is the most well 104.6767 95 79 33 _10 44 12 90 known nonlinear synthesis technique [291. Frequency 73 91 15 19 "94 103 . 8544 .2413 104.0958 99 70 20 _16 44 14 _7 modulation takes the composition of one waveform (the 74 93 - 18 17 95 104.3315 3.2208 107 . 5523 100 78 17 14 48 _14 carrier) with another wavefonn (the modulator). It is typically 75 93 _1 2 1 _1 implemented by using the modulating waveform as an 110.7087 2.9515 113 . 6602 91 78 17 1 49 " -1 addressing function into the carrier's wavetable. 93 _8 11 110.9497 5.6723 116.6220 99 81 16 17 " 72 Figure 16. The Alles digital synthesizer al Bell Labs. -" 77" 96 _18 0 122.1808 2.1033 124.2841 95 81 16 20 "57 "15 62 Another interesting technique is that of waveshaping [30,311. -'0 A1 the lowest end of the digital sound syn thesizer scale, several This method is based on passing a Simple waveform through a 78 97 - 24 18 -" 122.4878 .3729 122.6606 93 77 14 24 16 86 manufacturers are offering inexpensive "music boards" for transfer functioll which distorts it into a more complex 19 96 -23 10 100 122.7120 . 2434 122.9554 97 55 15 16 "71 95 personal computers. Anyone who might be tempted by the waveform. By passing the simple waveform through various 80 97 - 8 12 90 123.1179 6 . 3887 129.5067 99 44 25 - 18 low price of these boards should, however, think twice about parts of the transfer function over the duration of a sound 80 13" 94 their serious musical and technical limitations. The major event, tim e-varying spectra call be obtained. Figure 17. An example of Ihe output of a comp RECREATIONAL COMPUTtNG MAY·JUNE 1980 43 in some manner, with the perfonner. Another live use would [ IS] Kobrin, E. (1977) "Computer in Performance," Lingua Press, A key to developing more powerful software systems for Music analysis is another widespread application for be as an intelligent "stage manager" capable of responding to Box 1192, La Jolla, CA 92038. composition is the development of richer knowledge represen computers. Music analysis programs typically accept music Mathews, M. and Moore, F. R. (1970) "GROOVE-A Program cues by starting and stopping various aspects of the [16] tations for music. Not only should music be represented on data encoded in some standard fonn; the data is then to Compose, Store, and Edit Functions of Time," C4CM, performance. In interactive compositional situations, the the note level, but also on the level of large-scale fonns such processed with analysis procedures, and the results (often in Vol. 13, Dec. as phrases and sections. Representations which can capture numerical form) are then printed out by the computer composer could benefit from an intelligent assistant, able to [P] Gabura, J. and Ciamaga, G. (1969) "Computer Control of Sound extra-syntactic aspects of music may be even more powerful. program. A major music analysis project has been based communicate perhaps in a natural language (or a subset Apparatus for Electronic Music," JAES, Vol. 16, pp. 49·5l. [ IS] Friend, D. (1971) "A Time-shared Hybrid Sound Synthesizer," All of these notions of music representation fit naturally into around the MUSTRAN notation system developed by Jerome enriched by musical terms) with powerful musical capabilities. JAES, Vol. 19, No. 11, Dec. 92S-935. a grammar model for music, similar to models developed in Wenker of San Francisco [44 J. Other projects have been Such a system could answer questions (using large musical data bases) and even make suggestions in some cases. [19] Wiggen, K. (1972) 'The Electronic Music Studio at Stockholm: linguistic and artificial intelligence research [41 J. However, organized around dialects of the DARMS notation system. its Development and Construction," Interface, Vol. 1, pp. most music is too complex to be represented by a simple Techniques of analysis typically involve tracing the frequencies Summary 127-165. grammar (made up only of production rules), so some of various pitch intervals and other statistical criteria. [20] Goldstine, H. H. (1972) The Compllter: from Pascal 10 Vall extended grammar representations have been developed. Such Ho wever, some recent developments indicate that a cross Ne/l1wmn, Princeton U.P., Princeton. systems may allow a composer to work with music on many breeding between the fields of artificial intelligence and music Computer Music, though still in its infancy, has produced [21 ] Bowles, E. A. (1970) "Musicke'$ Handmaiden: or Technology different levels and with many different representations in analysis may be a very fruitful endeavor [45,461. The central significant results, both musical and technical in nature. in the Service of the Arts," in The Compllter and Music a single composing session. notion in this kind of research is constructing a system which Interest and involvement in computer music is on the ascent, (Lincoln, ed.) Comell Univ. Press, Ithaca. actually ''understands'' the music it is analyzing, i.e., it is able and the future appears promising. Though, of course, com [22] Mauchly, J. (1979) "Amending the Eniac Story," DatamatiOIl, Vol. 25, No. 11, October, pp. 217-220. Other Computer Applications to Music to build a coherent knowledge representation. puters will be abused in musical applications, as they seem to be in all applications in this society, many liberating possibil [23J Wilkes, M. V., Wheeler, D. J., and Gill, S. (1951) ThePrepaTation of Programs for un Alltomatic Digital Computer, Addison· The computer has generated new interest in many other Inteltigent Musical Devices ities are latent in computer music as well. Computer music has already demonstrated its potential for opening up entirely new Wesley, Reading, MA. musical areas besides sound synthesis and composition. One of [24] Hiller and Isaacson (1956) "Musical Composition with a Digital the most successful has been the application of music printing An intelligent musical device is an instrument which can not sound dimensions; digital processes have the potential for Computer," Program and Abstracu from the 11th National greatly improving audio fidelity and control. by computer [42, 43J. At least two automated music printing only remember musical sequences played into it, it can even Meeting of the Association for Computillg Machinery, UCLA, systems are thriving commercial enterprises, which produce listen and ' 'understand'' music. Such an instrument does not Aug., p. 8 and 22. Still, computer music consumes a lot of computational high-quality output scores for a fee. These are: Dal Molin's exist now, but there is considerable research and develop [25 J David, E. E., Mathews, M. V. , and McDonald, H. S. (195S) resources. At the time of this writing, it is perhaps still too "Description Music Reprographics of Oyster Bay, New York, and Data/and, ment work being done which could lead to such a device. and Results of Experiments with Speech Using expensive for the individual musician to own a computer Digital Computer Simulation," Proceedings of the 1958 in Aarhus, Denmark. An operator is shown playing in a hand Such an instrument will be able to recognize not only music system which produces good audio quality and is Natiollal E/ectronics Conference, pp. 766-775. drawn score at Dataland in Figure 18. A plotter traces the frequencies, amplitudes, and durations (as analog devices do musically very flexible. However, with the new generation of [26] Hiller, L. , and Isaacson, L. M. (1959) Experimental Music: computer-generated version in Figure 19. An example of the today, i.e. , frequency followers, amplitude followers, and microprocessors, increasingly massive main memory chips Composition witlr an Electronic Computer, McGraw·HilI, high-quality output produced is shown in Figure 20. New York. noise gates) but also larger syntactic fonns and fUnctional (e.g., bubble memory), and Winchester disk and other [27] Granholm, J. W. and Mitchell, M. C. (1957) "Music Transcrip characteristics of the music. Acting from a base of secondary memory technologies, a very good system may very programmed or even acquired grammatical knowledge, such a tion by Computer," Computing News, Vol. 5, No. 17, pp. soon become economically feasible. Digital synthesizers, even device will be able to listen and respond intelligently not just IOS-II3. as they enter the market at a rate of several per year, need to Alles, H. G. (1977) "A Portable Digital Sound Synthesis Sys· to sound, but to music. 12S] pass through a price/performance ratio one-half of what it is tern," Computer Music Joumal, Vol. 1, No.4, pp. 5-6. today. This, too, is only a matter of a short period of time. [29] Chowning, J. (1973) "The Synthesis of Complex Audio Spectra Immediate applications of intelligent musical devices are in Meanwhile, many individuals and research groups will continue by Means of Frequency Modulation," Compllter Mllsic the realm of digital sound editing, live performance, and to concentrate on highly interesting new musical applications Joumal, Vol. I, No.2 (1977) pp. 46-54. interactive composition. An intelligent sound editor could for existing computer music systems. [30] Roads, C. (1979) "A Tutorial on Non-linear Distortion or trace the path of a voice in a complex polyphonic texture; Waveshaping," Computer Music JOllmal, Vol. 3, No.2, pp. that voice could be modified or deleted without affecting the 29-34. [31] Le Brun, M. (1979) "Digital WaveshapLng Synthesis," JOllmal of other voices. This kind of context-sensitive editing capability References (crossing syntactic boundaries) is impossible today. In live the Audio Engilleering Society, VoL 27, No.4, pp. 250- 266. performance, an intelligent musical device could respond in [32J Roads, C. (197S) "Automated Granular Synthesis of Sound," [1 J Simon, E. (I 960) Mechanische Musikillstmmente froherer Zeiten OJmputeT Music Journal, Vol. 2, No.2, pp. 61-62. cues with various musical outputs, such as "following along" Ulld Illre Musik, Breitkopf und Hartel, Wiesbaden. (l3J Kaegi, W. and Tempelaars, S. (1978) "VOSIM-a New Sound [2] Struik, D. (1967) A Concise History of Mathematics, 3rd Synthesis System," Jouml.ll of the Audio Engineerillg Society, Edition, Dover, New York. Vol. 26, No.6, pp. 41S-426. $lui... " .J", ..... b_ de. -. _ ..... " [3[ Buchner, A. (l97S) Mechanical Mllsical InSf1llments, translated J .... P S MAY·JUNE 1980 RECREATIONAL COMPUTING 45 Megabyte Monsters! Power to the little spring that resulted from the casual took the task of implementing it. What APPLE HOTLINE people, the true people of the land of the union of an idiotic rochsaz and a dement resulted was a 56K BASIC program which little people. We demand equal publica ed gochref. I sure hope you get go!xeted eliminated the need for memorizing Apple II owners who plan to use their tion space! or by HEX tinyBAS1C will in the next election! numerical commands. Apple with a TV set should be aware of do battle with his brolher Billy BASIC/ the following. If the set has channels Now that I think of it, Fortran Man A Concerned Citizen The program accepts verbal commands quartz frequency controUed wilh no don't look so tough either! and responds by generating a game which user fine tuning as is the latest trend, HISTORY OF FANTASY GAMES reads like a book (or in this case, a TV the Supr. Mod II by M & R Enterprises Could you handle that on your con show). Of course you still have the op may not work. Use a modulator which science dragon? Not since the Civil War Dear Dragons: tion of visual displays, and although some has frequency tuneabililY like the one has brother turned against brother. elements are similar to those of more available from ATV Research, 13th After all are not tiny BAS IC and Billy With the continuing interest in Computer primitive Star Trek programs, comparing & Broadway, Dakota City, Nebraska BA SIC out to achieve the same ends? ized Fantasy Simulation games, it is mine with those would be like com 68731. CALL FOR MORE WORD In my latest book from Electronic interesting to consider the origin of paring V'ger to a tribble. Systems J noted a computer which is FROM THE ELF CONSTITUANCY All I would ask for would be the same such a concept. Our local version of Donald J. Stonek called the Quest Super Elf. It costs as space as SPOT. After all what does he Adventure credits Willie Crowther of There are over 40 possible commands, listed for the basic system $ I 06.9 5. The Cudahy, Wisconsin ATTENTION: DRAGON have that the ELF doesn't'? The Elf Stanford; but computerized adventures and elements and situations from 13 of expansion kits are all very cheap and the has a MONTHLY magazine caUed Quest were predated by the Dungeons & Dra the TV episodes. The program is truly massive expansion is under $90.00. This We checked with APple on this. Phil Before I attack, let me say tha t: date. That's all if at all, that Spot has. gons game, to which I was introduced addictive to those who play it, and to me. Roybal replies. - ED is not a plug for Electronic Systems but I would even settle for a quarter page by your periodical two na me changes I. I believe in the principles of the brings me finally to my I)oint .... space. ago. I am currently writing a second version Wanting very badly a computer I have I spoke to Marty at M & R Enterprises People's Computer Company in that ... which will run on a TANDEM com to get a reply to the letter that you sent "Computers are mostly used against saved as much as pOSSible, the money J If the megabyte tyrants are too much However, the CFS concept is much older puter system. This version includes all get for my services in the prison elec me. He confirmed that the present people instead of for people, used to above dedicating time to the lower than that. In Arthur Clarke's 1956 SF of the BASIC capabilities plus elements SUPRMO D II does not generally work control people instead of free them. It's tronics shop, which is top pay of one cases to give the poor and the young novel The City and tire Stars, the resi from the movie - the first to do so. dollar per day. I manage to save about 10 with quartz crystal controlled television time to change all that - we need a people's computer their tinle, when the dents of his future participate in "sagas." The program will have real-time cap sets. However, it is sometimes possible people's computer compariy." to IS dollars per month. Don't think that SUPER ELF I have ordered arrives These sagas: abilities and with any luck an infinite I want anyone to feel sorry for me, I to use the modulalor with such sets on I'll write the piece myself, if megabyte universe-as opposed to the usual 8 x 8 VHF, Channels 10 o r II, or UHF, Chan PCC/Recreational Computing, as an made my bed .... What I am trying to pride stands in the way. After all, all • are designed by humans quadrant universe of typical S.T. pro nels 32, 34, 64, 66, or 68. It will depend entity and as a publication emulates say, is that of all those things and persons I have is a love of computers and lots • are mediated by computer grams. (What idiot ever decided on an upon the television set. this philosophy in every deed and action. I have listed as being nOI, I feel J can and lots of time, (pardon the pun). allow great flexibility of action 8 x 8 array in Ihe first place?! .. .I've fmancially relate to all of these people. • To this I commend Ihee. • have definite limits beyond which yet to see a S.T. program which uses The influx of digitally controlled tele Power 10 the little people! participants cannot stray. bit mapping for quadrant representation.) vision sets during the last year has stimu 2. The expressed and stated ideals seek to Now, with the Super Elf, the poor and My program will also have interprocess lated M & R Enterprises to begin develop give all those who desire same, the chance the young can have a computer which is C. THOMAS HILTO N Clarke's sagas are only incidental to the communications capability (the TA N ment of a new modulator, which will be and opportunity 10 compute and access affordable to all. I might add that music, MONTANA STATE PRISO N, BOX book, so not much is written about them. DEM having up to 16 processors with available later on this year. This device to computers. Verily I repeat, I commend graphics and a video output are standard DEER LODGE, MONTANA 59722 The one saga described in detail never multiple processes running in each). This will work with digitally controlled tele thee and RIGHT ON. and it tells you what it is dOing as il theless sounds much like contemporary will allow two or more people to play wants to be your friend and have you visions and so will solve the problem Post Script : Mail may be sent to ones: Alvin and friends follow a floating simultaneously at different terminals, for users. Those goals are very commendable understand it. This is great in itself, but address above. This far out in the boonies arrow of light through the labyrinths of each thinking he is cap taining the indeed, however, I have been upset lately as , said, any kid can raise this money even hate mail is welcome. the Crystal Mountain after escaping from 'Enterprise,' but in essence captaining a with you and my favorite publication. which is in most cases less than a fi fth of the Cave of the White Worms. Kl ingon (Romulan or Gorn) when viewed I mean, I place you somewhere between a TRS-80 or comparable sySlems, and is We don't really discriminate; we publish from someone else's terminal. The next expectations awaiting the arrival of Play something that won't put the parent in the best of what is submitted. Sincerely, step would be for me to implement it boy and computer dream books, (ca ta hock to his ears. Al1 in all it is just as Gregg Townsend on a ComputalkerlSpeechlab synthesisJ logues). What more could you ask for in a advertised, a beginner's computer, bu t I'll be looking for yOllr articles about Tucson, AZ recogition system. completely expandable. Expandable, I THIS PUBLICATION IS computing magazine?? YOllr experiences with the Super-Elf. AVAILABLE IN MICROFORM might add, in affordable steps one can Be slire to get Tom Pittman's tiny BASIC Ollr next issue will be devoted to com Now the bad news. There are only iO Though I have been an avid reader of RC afford as well. modification kit so you can extend tiny puterized Fantasy Simulation Games. BASIC listings in existence, and the only "leas. send .... lIOaIHOtI.II~IOIm.II Of' for nearly a year, I do not have:l system BA SIC as you feel the urge. For the record, A dvenfllre was done by object resides at Drexel Univ. in Phila. So, I tum to my favorite computer as yet. So I am not an expert like most of - ED Willie Crowther (now at Xerox PARC) Five of the listings are scattered around University Microfilms magazine (you, unless that point has been your readers. 1 am not a parent, so cannot and extensj~ely modified by DOli Woods. the counlry, and I own the other five. International lost), for something on th is little beauty, fully understand the full desire of having To the best of my knowledge it was the The only TANDEM files are here with me 300 North Zeeb Aoad 'cause you represent the people, and what WE ' LL TRY HARDER my kids being able 10 use a computer for first really complex exploration game. in Delaware. Because of the time sent, Dept. P.R. education and fun. I am 3 1 now so can't do I find? How RC caters and plans 10 Ann Atbor, M148106 Can anyone add to the history? - ED and because I and Paramount own the U.S. A. fully understand the desires of a child to further give space to the megabyte or Dear stupid chazlul! copyright, I am loath to part cheaply wa nt to compute and not being able to rather mighly-bite-on-the-wallet com 18 Bedford Row with the listings. So anyone writing to Dept. P.R. afford a computer. I am in prison, so I puters only. It has come to my attention that your SUPER STARTREK me for a price quote _ .. beware! How London, WC1R 4EJ cannot fully undersland the parent or recent despicable and pultixious conduct ever, if there is enough demand (5 people) England common man who wishes to have for So, what do we fi nd? Once again we have Greet ings! on the floor of the Congress has caused I am willing to write a series of articles Name himself or his children a computer, and the power to the people, people, catering your colleagues to contemptuously refer on implementing the BASIC version on Instltul10n cannot afford one. So, I have fully to the powerful and the rich once again. Re Robert Howarth's letter in the Jan/ to you as a sunmabing gachloz. I find that a home computer. Street discredited myself to a point. I am a good Since the Elf and its cousins are the truly description of you too zokniming mild Feb issue. First, the good news. I am the City (if I may be so bold) electronic tech micro-computers, and now within the to say the least. ¥ou, sir, are a nozshim, author of a dialogue-based Star Trek S. Koren State z" ___ nician, however, and dream of computers range of all the masses and not just the a xatlizog, and a blithering mathfig! progra m. I foresaw the need for such a Newark, DE and of owning one. rich, I say unto you .... Down with the , have no doubt you're the sosroring off- program several years ago and under- ., - ANNOUNCEMENTS c/o w. Don McKell, Indepen Writina Workshop in Computer example of it in use, and cross CT 06432. Offerln" for tM r dence Hiah S<:hool, 1776 Educa Science (Wilkes) and Formal refnencin8 related cllds. The TRS-SO, PET, and Apple tional Park Drive, San Jo.se, CA De5i&n or Computer cards Wire deaigned by Un compulert Ite described. 95133. I Lindsay espedib!i. (or Sludents. self. contained computer system. listing, user " manual, and pro of text proc_inJ: flltl1l'u. Cott The Future of Computing A F REE fanrgld" ick reference A catalog Ilstlng a variety of Hardware The Electric Crayon with the gum documentalion. A 9-traek is $99.95 from Muse Software, neld-tested educator_designed !!mphasizi"" microprousson, "Ide will be d wilh any EGOS Opentln8 syStem, I K magnetic tape of the BASIC 330 N. Ch.arles Street, Baltimore, o rder mention_ «:rearfo"a/ programs is available from Cook', am.n computers, home com Z-SO Softcud for the APPLE bytes of refresh memory and a wures code Is aLso available for MD 21201. 30 1/659-72 12 Compurfng. lnlt;,udlACt ory price Computer Complny, 1905 Baily Iddltlonal $J5. Singular pute",. and distributed ~o«ssinl offers Apple owners a second users manull IncludinJ: an _m an for Ihe ATARI BASIC CARDS Drive, Mal'lhalllown.lA 5015S. is the sub~ct of • nne day ACM processor and the possibility of bly la nguage listing of EGOS and SYiteml, 8 10 Stratford, Sidney, CAIW ARE and SUPER -CAl lie is o nl y $5.00 fro m Mic:ronotion" wftware ,ystems for .uthorinl Golden Gate Chapler seminar In runnin, 80S0/ZS0 progranu on BASIC demonstration programt OH 45365. TRS· SO Software Duplication theit Apple including the popu seiLs for $249.95. Cabling, addi and ulm8 Computer At;sisted In be given by Portia Isaacson and ~a~~~~~":3~~ive, Room 6, Special Limiled Time Orrer. Dr. E,il luliussen. May 10, 9am· lar CP/M operatln, Iy.tem. The tional refresh memory and de. TRS-SO BASIC Compiler an· $IruClion on a 16K TRS-80 with Mierosette Co. can now duplicate no unced from Microwft Can· Level 2 BASIC. CAfWARE on 4pm " the HYatt Union SqUIlTt!, Z-SO Soft Card will run on all monsuation programs on mini TRS·SO" Yellow Pages 2.1 is I TRS· 80 level II ClQette programs cassette with manual COlts San Francisco. $40. For infor_ configurationl of the Apple and diskt an extra cost options. sumer Products compile. pro sixteen_page newsJeller/cataloll to load over I volume setting malion contact Fred Collins at requite. no hardware or soft Percom Data Company, 211 N. lIr1ms wrillen with the TRS· $24.95; SUPER.CAI with manual from 4 to 8 or more on all Radio (415) 357-5272. devoted entirely ~ ,eriOIl.l blUi. ware mOdincatlon,. It will plug KirbY, Garland TX 75042. (214) 80 Dilk BASIC interpreter, pr0- COSII $44.95. The manuals lie Shack caMIlle deeks (CTR_40, available-.ept\rately for $9. Micro nes3 soflwan. 'h ". '¥Iy into any of the peripheral , lOll 272·342 1. ducing Z·80 mlchlne code tlu-t and useful guide for ..a.cttn8 CTR -4 1, CTR·80)I Even with is directly exeeuted by the Gnome, Fireside Computln8, Inc., Tenth Annual Institute in except JlO t 0 and does not I ffect bualne.ss soflwlle the ~-SO the pl.,blek head purposely mis 5843..Montgomery Rd., Elkridge .. pUler Science. NiM or the operation of the Apple when TRS·80. computers. It des '" the aligned, these tape. will u ill load MD 21227. computer short not in Z·SO mode. To use the Software software p r odue~ by Micro reliably. The packa8e Includes two disk gramminr SoftCard wil li CP/M and Disk Programminr Language Architect. II's diltribute free BASIC requires 4SK RAM and PL! I-SO from Digital Research ettes containinl the BASIC Electra Sketch is I grephl" and (provided you d ]ong, Our charge for this service Is CompHer, BASIC runtime library animation compiler for the TRS- one disk drive. Deliverlel begin Implements the ANSI General (SysteArbibm andPerformanC(! Manes) PI":~i::~I::; "''''''~ . ta mped, self_ad r enve. $2 17.50 for 100 copies minimum in June. Price i, $349. For tile Purpose Subset of PLfI as a Bnd LINK·80 Iinkln8 loader; 80. Pictures can be created using lopes) by Miero Architect, 96 prepaId. Cllifornia customers complete Instruction manual for simple one key commands and (Sevcik, LaZQwska, Graham M i cf(lnotion5;;,-~''''''''''AS IC: please add sales tax unless res.ale na me of the nearest dealer con· compiler for the S080, SOS5, and ZahorJan), Deslan and lmplemen_ CARDS, an auy to understand Dotllan Street, Arlington, MA using BASIC Compiler; and s.aved on disk for later recall. number II su bmitted. Shippillg is tact Mierosoft Consumer Products, ZSO. The package runs under the talion o f Modular Software reference for ATARI BASIC is 02174. complete reference mlnual for Animation effects are obtained by UPS to o ne address in the 10800 Nortlleast Eighth, Suite industry standard CP/M and MPI (Gutta, Illld Liskov), Operatin8 now available. ~ch BASIC by. 507, Bellevue WA 9S004. (206) M opera ting systenu also de Miero,oft 5.0 BASIC. Suggested by displaying a sequence of A catalog of eduelliloltal sofl· United States. Mlcroselle Co., retail price is $ 195. Contact stored frames o n disk. The pro SYitenu (Holl), Compiler Con- word hu its own card, Ulullratlng ware U a\1lilable "fTom QUEUE, 475 E]lis Street, Mountain View, 454- t 3 15. veloped by Digital Research. The Suuclion (DeRemerandPennello), Its correCI Iynllx, brleny ex- Microloft Cons umer Products, gram is lvailable on CUlelle for 5 Chapel Hill Drive, Fairfield, CA 94043. 41S /968 -1604 full package, including compiler, Code OptlmizBtion (Ullman), plalnin8 ill lUe, $howln8 an subroutine library, linkage editor, 10SOO Northeast Eighth. Suite $14.95 from Macrotronics, t 125 Sup"R'Tennin:tl. an 80 Column, S07, Bellevue, WA 9SOO4. 206 1 N. Golden State Blvd., Suite G, 24 line uppar{lower case display and relocaling macro assembler 454·1315 Turlock, CA 95380. option ror the Apple I I, Is avail . and full documentation cost able from M &. R Enterprises. $500. An impressive syueml muMATII for t1te TRS·80 is a Apple Animation As with the car, we limit the excursions Digitl l Research, P. O. Box 579, 3000 REM ERROR·CHECK SUBROUTINE The Sup'R' Terminll board is symbolic math paekage that of the road so it won't go off the screen. user,instillable and compl tible 80 I Lighthouse Avenue, hcinc brin" sophis ticlted math CIPI Other Continued from pg. 27 3005 SPEED - 256 - PCLO) with most standard software. Grove, CA 93950. 408 / 649- bility 10 tile TRS-80 for the Naturally, we also need a subroutine to 3010 FOR W - 1 TO SPEED: NEXT W 3S96 Remember NOC 1980 - The Na Cha.rlcte.. are represented u a first time. muMATH" capabilities erase the road: lOI S IF XO > RO ANO XO «RO + 7) THEN 5x8 dot matrix. Board·based Inelude eXict rationll arithmetic tional Computer Confere nce and RETURN A C Compiler for the 6SOO has Personal Computing Exhibition - 2005 IF XO <0 THEN XO = 0 .,ftwlre hlndles such functions and lutomatic algebraiC simplifi· 3020 PRINT" ": REM CTRL-G just been announced by Wintek. MIY 19.22, Anlheim Convention 2010 IFXO>34THENXOz34 4000 REM ERASE·ROAD SUBROlITI NE IS upper flower C8$e shift. eurtar callan. The user can conlro l such 3025 ERR - ERR + 1 movements and modes, ,crolllni C is I powerful syslems languaae transformations al expanding Center, Anaheim, CA. For inf~. 4005 COLOR" IS 3030 RETURN model Ind contwla, clearinl and developed by Dennis Ritchie for poWlrs of polynomials Ind malian, contact AFIPS, IS15 N. Just moving the car around on the screen 4010 GOSUB 1025 linefeed functions, and e haracter the UNIX system at Bell Labora placinl expressions over I earn Lynn Streel, Arlinlton, VA isn't much fun, so let's add a moving 4015 RETURN dennilion. UlCrs ean define their tories. The Wintek C is designed mon denominator. Other capa 22209.703/243-4100 road to test our driving skill: We input the speed from game paddle 1 own chlracler seu Ind switch to run under the WIZRD mwti· bililies include trillonometric and We save a line of code by using part and wait a while before dOing the error back and forth It will. Retail tasking disk operating system on logarithmic limplincatiQns and Call for Computer Musicians and the SPRINT 68 computer. The Artists to speak, exhibit, o r 1000 REM DRAW-ROAD SUBROUTINE of the road-drawing subroutine, changing check. If the car is off the road we beep prlee is $395. See your dealer sYmboHc differentiation and the color to white. Bit-pinching really or contact M &. R Enterprises, compiler COSII $495: the com inteualion. All operations in mu· perform at: PCAF 'SO, Personal 1005 RO " RO + RND(3) - 1 the speaker and increment the error P.O. Box 6 10l t , Sunnyvale CA pu ter with 4SK memory, dual MATH are performed with Compuler Arts Festival, Phill 1010 IFRO I'm not without my up the dielectric And there is only one among them ; , own pow..... Glitcnmlltlt'l City. joining node-IO strength and courage to race such a foe . fiendish-looking device that appeared out of I'",. 'c:1:I"'lted my ~to Still, F -Man's opponent scems unperturbed networKS of General Wire and without PAUSE the ever-ready Fortran nowhere is just IS quickly triucred into inc:rwn,nt func:tion , .. end the moment they are needed Man accepts the challenge! opel1ltion , , . aimed directly at Our Herol ",.ry putse you hit m. with i. automatically com So ... it Is to b•• contest of On through the city !tis flowpatb progres.ses, pengttel fori Still the charge barrier holds.. . that and into the dark hardware halli of the your POWII' egainst miflfl, I. it1 ~ is, until Fortran Man, accompanied by his Glitchmaster's personal stronghold ... TesI.a !t ... ith.no ally and friend Billy Basic and ridiJli the To~r! His array-prooessiJl& powers allow effect on you1 ~!-' " back of the powerful Lockout Monster, him to easily fmd his way through the --,-'. ,.,.. ' flies over the besieged city and releases matrix of corridors to the very portal of the a va.U barrage of ... random passwords! Master Control Room! With an abrupt OPEN FlLE statement, the port is activated With their me-protect keys destroyed, the •.• and then ... great data stIuctures crumble, and the holdup potential of the waU, is reduced ... All riiht. Glitchmas'er '" come on out! Your state whereupon the current chllliC of the resist ance causes the capacitive guards to breaJc m.nt number is up" , prepare to be executed! down, ' , and the city is theus! I When last we lert ~~~:. F-Man makes one quick motion of his • of the great battle the And yet the war is not yet won. , . not own, , . and then stands flmlly in place, proccssorland had at last until the source me of the conflict hu been as the incrementing pulse~ reflect harm Very well .. ,I eo forms the lead of her faced and eliminated", the G iltchmaster lessly from the body of his code! cept the c:hall.n~1 himself! ~... Even the great ForUan Man, who has en And for the Hl'St W.I!, h.rm'" as you may appear, And once again, before F-Man can respond countered and solved for many an unknown executes an abrupt HALT, as your timer is up I Eith.r you algorithm, is somewhat baffled by the format the strange-looldni creature that addresses surrel'ldlt' puONbly , , . or f!tee W.II thp, Ie .. ,.. how you him from across that room. , , of the odd creature before him now, But this aUack Our Hero manages to avoid Immediate ,.rmiOlOtion I So you hendle a Ittti. $ta tlc, F· as well, . , but not by much, as the razor ~~~~~~~------,~ might. _II iive up . , .since Manl you're gain{! to lose anywayl edged Poinler invades his program space Try on my NoiH Pu/"" G.n'flltor I' ll klHlP my own Why. of c:ou"', F-Manl A Gliteh Is nelffl' whit Yet our Hero has no time for null cycles .. , you expect it to bel for this attack is followed immediately by ! to II I Don't look now, Glitehmester, And with equally fast responsc time, F-Man There is a brief PA USE in the battle, and no, F·Manl I'",. only JU$l but I don't '" .ny ... ' counters the attack without reJistering a once again F -Man appeals 10 his foe . , .. single hilt tJ.gun to demon$lr.te , II the d.vices It my dispoAiI Nic:e try, GlitchmlStlr ... Now th.n .,. if but this Static Shiflldshould _',. don. with the Inititl hudil1lll. shall w. OIt on with the m.;" body of our btttl.1 be the outcome luch a battle? Can Our Hero avoid rorever the seemingly endless arsenal of weapons the I Glitchmasler can throw against him? Will this most insidious and annoyinl of all villains ever be bro",ht to justice before Why, of eourse not! OM of the the Debugger". or is Fortran Man grlltest powe... of a Glieh It th.t dutined to become pennanently imbedded you never,.. it c:omln{! until Giv. It UP. GlitehmlSteri with Glitchy code? Will Microproccssor fect, I'd adlli. you to pr. it $trikesl Land ever be noise-free again? ~~:~-..J,\\~.~.~.~m:Y~O~ff,By.one tnduc:erl ..."- __-i For~t all this noise and par. for you, "rmiOlOtionl You com. with me quietly! For the answer to this and other externally _. I hlY •• formld.ble arrey of Prepare to be shifted parme Won't you admit you sim induced questiON, tune in again next _.pons It my dispOSIII .... nenlly out of $tep, F ·Man! I can't win1 , .. same risetime, same cycle! 50 RECREATIONA L COMPUTING MAY-JUNE 1980 51 - BAC~ISSUE§ pee NEWSPAPERS 1977 - People's Computers All 12 available back i$$urn of PEOPLE'S COMPUTER COM #27 May·June 1977 Graphics, Computers & Copyright Laws, PANY NEWSPAPER for only $'5. Over 1/3 off regular pric6. PILOT & Tiny BASIC, Home Computers for Beginners, Women & Computers. $2.50 #3 May-June 1913 ZINGO/"Going to Bid"/How to Buy an #28 July·August 1977 Heathkit's 80SO & LSI·", Do·lt· Edusystem/BASIC MUSIC/CHOMP. $2.00 Yourself CAl, Robot PETs. $2.50 #10 July-Aug 1974 A Fantasy of Future Forms/low-Cost #29 Sept·Oct 1977 Compurer Networks, Tha $595 PET, Home School Microprocessor Systems/INCHWORMI More Tiny Languages. $2.50 MAZE/Analysis of Teaser/Computer Illiteracy Problem # 30 Nov·Dee 1977 Oz Graphics, Bio·feedback & Micros, by Peter Lykos. $2.00 Our PET's First Steps. $2.50 #13 Jan-Fab 1975 Build your own BASIC/Mysterious ANDI More I NCHWORM/Computers & Art!BIOSIN Son of 1978 -People's Computers Hardware. $2.00 # 18 NOV-OK 1975 NUM8ERfTiny BASIC/Analog to Digital #31 Jan·Feb 1978 Robots, Video Discs, PET Update & Pro Conversion/MinuBt in G Major. $2.00 grams, PASCAL & COMAL. $2.50 #19 Jan-Feb 1976 Space Gamlls(Tiny BASIC Soloworksl #32 March·Apr 1978 Epic Computer Games, TAS·SO Rllviaw, DIDDLE/STTR/More Music. $2.00 Micros for the Handicapped. $2.60 #20 Mar-Apr 1976 Games for the Pocket Calculator! #34 July·Aug 1978 Computer Whiz Kids, Public Access to SQUARES/Make Beliew Computers/STRTRK/Hunting· Compute .. , Man·made Minds. $2.50 ton Computer Project. $2.00 #35 Sept·Oct 1978 Computer & Museums, Kingdom, APL, #21 May·June 1976 Biofeedbsck/POUNCE/'We're Building Sorcerer of Exidy. $2.50 Our Own Computer"/Programmer's Toolbox/ cccrrv as #36 Nov·Oee 1978 Thlt Aeturn of the Dragons, APL, Ani· Terminal and Game Center. $2.00 mltted Games for TAS·SO. $3.00 #22 July·Aug 1976 Low Cost Softwarerriny BASIC, Tiny Trek/Your Brain is a Hologram. $2.00 1979-Recreational Computing #23 Sept·Oct 1976 Dungeons & Dragons/HATS/One on One/ PLANETSrrhe Positive of Power Thinking. $2.00 #37 Jan·Feb 1979 Artificial Intelligence, A Fantasy by Jules #24 Nov·De<: 1976 STORY/SNAKE/More Build Your Own Verne, TRS·SO Personal Software, The Apple Corps is Computers/Introducing PILOT/FROGS. $2.00 with Us. $3.00 #25 Jan·Feb 1977 REVERSE/Robourriny PILOT/Spsce & #38 March·Apr 1979 Artificial IntelligenCII, Calculator Com· Compurers/Conversational Programming. $2.00 ics, Chess Reconsidered, Lord of the Rings. $3.00 #26 Mar·Apr 1977 Z·BO PILOT/6502 Assembly Program· #39 May·June 1979 Now Perer Can Read, Game of Life, ming/Tiny BASIC for Beginners. $2.00 TRS·SO Programs, Derective Game Program, $3.00 Only the issues listed above are available. Price includes #40 July·Aug 1979 Computertown, U.S.A.I, Cryptarithms, issue, handling, and shipment by second class or foreign DP Games Playing, FORTE Music Programming Language, $3.00 surface mail. Within the U.S., please allow 6·9 weeks to #42 Nov·Dee 1979 Shogi Games, Creating Naw Characters on process your order second class. Outside the U.S., the Ti 99/4, Music for Atari, TRS·SO & PET, $3.00 surfacemail can take 2·4 months. For faster service # 43 Jan·Feb 1980 Computing for Health and EqualitY (PET), within the U.S. we'll ship UPS if you add$1.00 for 1·2 Ti Graphics & Animation Pt. 2, More Music for Atari. issues and $.50 for each issue thereafter. We need a $3.00 street address, not a PO Box. Outside the U.S., add #« Mar·Apr 1980 Special Game$ Issue! Recreation Apple II $1.50 per issue requested for airmail shipment. Hi .Aes Graphics, Galaxy II, TAS·SO Tiny Trllk. $3.00 ClrdI you, choice.. I MClOII • _ (U$. check Of money Ol'der) foreign add $.&0".,- ...... (ttl .. includes POIUg! and hIIndiingL 3 10 13 ,. 1. 20 21 22 23 24 2& 21 21 21 21 :10 31 32 34 36 38 ':r1 38 39 40 42 ...... lind In thil form or fetlimlle to: PeOPle', CompUter Co., 1283 EI c.rtIno RMI. Box E, Menlo P.k CA 9402& ...... tend me th.1aun circled. DYft,..,d me #a-28 for only '151 ...------ WMlt. ~------D"m ordering 120 or more and I 1,", diIcount. CI~$~~ ______SEND FOR OUR BUY DIRECT FROM NCE/ CompuMart r 1O-DA Y FREE TRIAL FREE CATALOG reasons for WE'VE GOT IT! s ••ed on our policy of offe,'ng your PEr~ from Lear Siegler Terminals customer. only the fin •• ' In micro (1) $100 IN FREE & Printers At A Calculator, A system, A YYh,ol"1 compute,., CompuMert is pl••• ed to WITH 16K or 32K PET. Tremendous SavIngs New Standard. announce fl••• we now carry the new W,"-n you buy. 16K Of32K PET . apply ' 100 '0'0II'., <1 The Iln•• t calculators available lor generetion 01 Persona' Computer. by PET ~ FREE. CI>oose ',om ,,.. _ .\O ..... 3A. lnaustr!es' Science, Engineering, & Bu,lness. At.ri. ... _ III'..:! below end IncMut. on your Of