RANDOM REMARKS

Concerning RND(X): Memory locations 218-222 store previous random number, in usual PET notation: R = ((((PEEK(222)/256 + PEEK) (221))/256 + PEEK(220))/256 + PEEK(219))/256 + .5)*2t (PEEK(218)— 128)

To “randomize,” try a statement like “X=RND(—TI).” Don’t use the re­ SPOT sulting X, but call RND(l) thereafter. The Society of PET Owners and Trainers (RND(negative # ) fills memory loca­ tions 218-222 with a scrambled-bytes version of the argument.)

Mark Zimmermann Pasadena, CA

PET VANCOUVER PETS The Vancouver PET Users Group recently POINTERS held their second meeting. The success of the PET has caught us all by surprise. The attendance at our second meeting • • • was over double the first, with some 40 owners and 15 PETs. The Commodore PET LISTING CONVENTIONS dealers indicate that there are many more PETters who are not aware of our group. PET Program listings in People’s Com­ Interested persons should phone Rick puters employ the following conventionsLeon at: (home: (604) 734-2060); to represent characters that are difficult (work: (604) 324-0505). They can also to print on a standard printer: Whenever write to: square brackets appear in the listing, neither the brackets nor the text they Vancouver PET Users Group enclose should be typed literally. Instead, Box 35353 Station E the text between the brackets should be Vancouver, BC translated to keystrokes. For example, Canada [CLR] means type the CLR key, [3 DOWN] means [DOWN, DOWN, DOWN] The club format includes a short presen­ i.e., press the first CRSR key three times. tation by a PET owner on programming on PET hardware, news from Commo­ • • dore and other sources. Followed by PET Patter and program swapping. TAPE TIP PROGRAM TAPE SEARCH I recently bought tapes and was able to load only one side of each tape. I I use an external cassette recorder with couldn’t load the other side and was my PET, and I have 10 seconds between ready to mail them back until I tried this: programs on a tape (recorded at zero Commodore's PET is a factory assembled I placed a small piece of cloth (about volume). This makes it possible to locate personal computer based on a 3/8” 6502 by 2”) under the cassette and any program using a SHARP RP 1155 microprocessor. The $795 system in­forced the lid to close. Then they both Deck with Automatic Program Search cludes a keyboard, cassette tape unit, loaded O.K. Maybe I aligned the tape System (APSS). On fast forward or built- in TV screen, some graphics, upper and tape head by doing this? R.L. Mc- rewind it will stop at the first blank in and lower case, and extended 8K BASIC\ Arthy, San Clemente, CA. the tape. Great for verifying and locating and 8K o f user memory. Each bimonthly programs. issue o f People’s Computerssince the Who knows. .. but it certainly sounds September-October 1977 issue has in­worth passing on the information. ThanksJack Clark cluded an article on the PET. for the tip. -Ed. Oxon Hill, MD

48 PEOPLE'S COMPUTERS points if you consider the more negative pressed, it will put a 255 (or FF PET PAWS features of its keyboard design. Obvious­ hex, or the Pi character) in location ly this keyboard is best suited for young 515 (or 0203 hex). If a key had users with small hands. It is apparent that been depressed, a simple contact many adult users would prefer a larger, was made from one of the ten more standard size keyboard to work strobe lines to one of the 8 return with, especially when they want to enter lines. The BASIC would then have a lot of text, graphics, or data. It is partic­ inserted a value in location 515 ularly true that when the PET is used for which was equivalent to the sum of business applications, often requiring the decimal numbers in the corre­ large amounts of data processing (number sponding row and column (as in­ crunching), the present PET keyboard is dicated in the first diagram to fol­ not so well suited for rapid data entry low). in volume. The KYBD plug/receptable on So, we must conclude that for some the mother board (inside the purposes the PET needs a new set of PET) has numbered strobe lines “paws.” And for those SPOT readers and lettered return lines. If you who may be interested in checking out arrange your add-on keyboard KEYBOARD HOOKUP the following reprint of an article on this strobe line connections according topic, here is a solution to this problem: to the pattern in the second dia­ In a recent SPOT column we learned that gram to follow, so that they make our PETs can be trained to speak (via “So you don’t like the KYBD contact with the return lines hard copy printout) using a Diablo that comes with your PET?!!! Well (indicated by the lettered groupings Printer and a PET ADA interface (see the it has proven to be a snap to add on over the diagram in figure 1), article on “PETting a Diablo,” Jul-Aug of your own KYBD . . . and I do mean then you can connect your eight­ PC, p.47). Well, now it is also possible add on, not replace! een lines to the existing KYBD to produce, if you will, a new set of Since encoding the KYBD in­ plug (in parallel) and still retain “paws” for our PETs. (“Paws” in the formation for the PET is done by the graphics keypad on the PET!!!! sense of a new kind of keyboard for the the BASIC under the 60-cycle PET... or, another “set of fingers,” a interrupt, there is only one of ten As an example: a #4 strobe new “hand,” so to speak). I am alluding, lines strobed out to the existing line connected to, and returned of course, to the possibility of wiring up KYBD (10 by 8) matrix at a time. by an “E” line will print the another, more standard kind of keyboard The BASIC then looks to see if character “P”.” to the PET-one which will work in paral­ there is a return of this strobe on lel with the existing PET keyboard. any of the eight returning lines This excerpt was from an article orig­ from the matrix, caused by a inally printed in the “PET User’s Group depressed key. If there is no return Newsletter” (volume 0, no. 1), published As Ludwig Braun pointed out in a recent of the strobe, the BASIC chooses by Pete Rowe, for the PET Computer review of the PET which appeared in another of the ten lines to strobe Project, Lawrence Hall of Science, Creative Computing (see page 24, July/ until it has gone through the full ten, Berkeley, and was written by Neil Bussey August issue), the PET does lose some when, if there have been no keys and Richard Tobey.

Columns by alphabetic groupings

Rows ~ \ r E

rm] INST 64 fBl fO1 rm rsn* r*n P-n faTI m n # $ % l&j \ ( ) DEL 1 2 1 2 ' □ ' B 1 e ’ D □ h a □ □ 7T 48 3 4 3 4 10 : n w E R T Y u i 0 P , 4 , Strobe Rows a ’ D ' ' CD ' ’ B rw] □ □ R 32 f * E 5 ^ 6^ ^ 5 ^ 6 (connected (U s D UJ G H J K L T U in even /odd R 16 m p n rw\fin rai fTsT fa] n n fan ffl 7 8 7 8 alternating z X , c , V B N M ? N order) ' OFF ' RUN 0 SHIFT RVS B SB OD SPACE a SHIFT B 53 G9 a 9 10 9 10 ON J I® J [ 13 < > (STOP) 16 8 15 7 14 6 13 5 12 4 11 (3) 10

Return lines are indicated by the alphabet in 8,coJumns A thru H.

Figure 1 Figure 2

NOV-DEC 49 In my experience, it was a little bit more than “a snap” to add on my own key­ board to the PET! However, I can now say that all my effort was really worth it, because now that I have another key­ board to use with my PET it is really easy to sit down in a comfortable chair and enter in long passages of text or a great many data statements! With a larger size, typewriter-like keyboard, it would be quite easy to type in text at 60+ wpm speed (with the aid of a mini-word pro­ cessing software system). If you are able to wire in a 3-foot long ribbon cable from the keyboard to the PET, then you could conveniently place the PET on a table top and still sit nearby in a com­ fortable chair with the new keyboard resting on your lap. Now isn’t that a neat way to make home computing fun and comfy?!! CONLEY VS. COMMODORE than the 8 -page throwaway that came with the computer. Itwas on shiny paper, For those of you who might be in­Thanks for the copy of People’s Com­ though). terested in tackling this project of adding puters. (I guess my subscription has on another keyboard to your PET, you expired—just can’t figure out the Greek The ROM wouldn’t fit!!! $(®#%

50 PEOPLE'S COMPUTERS PET PRODUCTS The pocket sized issue ran 40 pages in July ’78, and operates on a small income S-100 BUS CONVERTER BY EXCEL adapt the KIM, the MOTOROLA EVII, from advertisers. Copies are free to indi­ and other 6502 or 6800 computers to the viduals, but they would love any dona­ Excel Co. has designed two products SI00 bus using the appropriate connector tions you can send. It’s worth it for the to extend the usefulness of your PET. cable. This board is unique in that it helpful bits of information that isn’t One is the S-100 Bus Converter (SI00 generates all of the required SI00 control readily available elsewhere. Contact: BC), an inexpensive device to allow yoursignals such as Psync, I/O address, wait PET to interface with the many S-100 states and — much more. This is the same Len Lindsay, Editor products on the market. Some of the design that has been proven by CGRS Pet Gazette boards that can be used are Godbout’s over the past several years with their 1929 Northport Dr., Room 6 4K, 8K static memory; Solid State S100 6502 MPU card. Madison, WI 53704 Music’s 4K, 8K static memory; and IMSAI’s Multiple I/O boards. The SI00 The PET/S 100 comes with instructions READ, WRITE PET MEMORY© BC is $85, not including cables and and a complete SI00 compatibility list. connectors. It is available fully assembled and tested The PET computer’s BASIC language for $195.95. Send check or money order instruction set provides four commands/ The other product is an ASCII Keyboard to: CGRS Microtech, Inc., PO Box 368, statements which allow the programmer Interface. It allows any ASCII encoded Southampton, PA 18966. to store and execute machine-language keyboard to talk to the PET through programs. There are: POKE, PEEK, the same connector as the original PET PET CRT SPACING CHART SYS, and USR. The POKE statement, keyboard. No modifications are neces­ which stores data directly in memory, sary; and since the PET keyboard is not PET CRT spacing and layout charts is a little clumsy to use because it takes disabled, it can be used for all its orig­ are available in 8Vi by 11 inch pads. a separate statement for each memory inal functions including graphics. The With green printing on white background, position; and the address of the memory Interface is $80. For more information one side shows 25 numbered rows by 40 position, and the data to be stored have contact: columns for planning your PET screen to be in decimal form. Addresses and output. The other side is printed with memory contents are usually expressed EXCEL Company spaces to record BASIC variable des­ in hexadecimal form. P.O. Box 1147 criptions, subroutine descriptions and El Cerrito, CA 94530 also shows the PET keyboard with The Read, Write PET Memory program ASCII codes, approximately 50 sheets by Don Ketchum, greatly simplifies the CGRS MICROTECH S100 ADAPTOR per pad at $2.00 each, or 5 pads for entire procedure. With this program you $7.50 post paid. store data in memory by simply keying CGRS Microtech, Inc. announces the in the starting address (in hexadecimal) PET /SI00 adaptor. CGRS, the 6502/ Alcorn Data Services and then just key in the hex digits in the SI00 experts, have developed an adaptor P.O. Box 1535 sequence in which you want them stored. card that will convert the “memory Corinth, Miss. 38834 Nothing could be simpler! Here is a list expansion” connector from the PET of the functions which can be very easily computer to the SI00 bus. With this card carried out with this program. (All data the owners of the PET can expand PET GAZETTE and addresses will be in hexadecimal.) memory, add I/O devices (printers, 1) Write into memory. floppy disc, etc.) and enjoy the advantages The Pet Gazette is an informal publica­ 2) Display memory (both as hex of the numerous SI00 products. tion that includes reveiws of software digits and as assembly language and equipment, tips on operating and mnemonics). The PET/S 100 is a single board that plugs using your PET, and a software exchange. 3) Change data in memory. into a card slot of any SI00 motherboard The Pet Cassette Exchange has over 150 4) Save memory on tape. and connects to the PET memory expan­ user supplied programs available for only 5) Load memory directly from tape sion connector via a flat ribbon cable, $1.00 each. The Gazette also features starting at any selected memory the PET/S 100 adaptor can be used to subscriber donated articles. address. 6) Execute machine-language pro­ grams.

Read, Write PET Memory (Copyright 1978 by Don Ketchum) is available on tape cassette, $7.95 postpaid from: Don Ketchum 313 Van Ness Ave. Upland, CA 91786 □

NOV-DEC 51 REVIEWS

TELEPHONE ACCESSORIES YOU anyCAN surprise that Michael Scheff opened loopholes; obey and pay Bell; or ignore BUILD his introduction toThe Pushbutton Tel­them. Telco propaganda generally en­ By Jules H Gilder ephone Songbook with these words, courages you to believe that tariffs are Hayden Book Company, Inc, 1976 “About the only bond people the world laws. In general, they are not. 84 pp. $4.95 over seem to have these days is (1) a desire for peace and (2) a dislike of Tariffs are rules of system use including The telephone is to electronics as mili­ The Telephone Company.” The Song- fees for service, made up by regional tary thinking is to thinking. It is intended book was Scheff s effort to help improve telephone companies (plus AT&T for for only one use—to carry the human the telco image. long distance service), and submitted to voice (or a modest reproduction of it) utility commissions and the FCC for from one place to another and work The Bell System has long had the very approval. In spite of all the discussions when everything else fails. The secrecy best technical reputation and a consist­ of “illegal” extensions you have probably which surrounds this device is legend. ently poor record of human relations. heard over the years, violation of a simple If you doubt the legend, try this experi­ Three factors are known to have im­ tariff is not a crime. The worst that could ment. Call your local telephone business proved customer satisfaction with Bell happen is loss of phone serivce until office, and order a schematic for your services: (a) federal court litigations and you agree to abide by the rules. telephone. FCC rulings; (b) actions before the state public utility commissions, and (c) Having said that most tariffs are tooth­ On second thought, to actually do the disclosures of financial and technical less, please note that there is also a short experiment may be a bad idea. If you information to the general public. list of laws which make some irregular are the sort of person who might read, acts, illegal as well. It is a crime to: enjoy and act upon Telephone Acces­Technical disclosure is necessary because make obscene calls; fail to yield a party sories You Can Build, then you may not Bell made a practice of telling technical line in an emergency; commit wire fraud wish to suggest to the phone company half-truths biased toward gaining favor­ (i.e., use a Blue Box to avoid long dis­ that you are about to peek and poke able regulation. The most outrageoustance charges, or use a computer to steal into their instrument. Ma Bell’s reason example is that of the infamous Voice money/secrets/data via the phone lines); for discouraging you is simple and mech­ Connecting Arrangements. Gilder briefly commit a few other acts such as theft anistically logical. If you and millions of discusses them in chapter two. The of telco equipment. other people are allowed to unscrew “need” for VCAs was hastily discovered telephones, and place Foreign Attach­ following the 1968 Carterfone Decision, Chapter three contains some simple and ments on the line, the reliability of the but this need was actually financial, clever methods for quickly making entire system will be reduced. And this not technical. The Carterfone, by the printed circuit boards using among would be a violation of the prime direct­way, is a two-way radio phone patch. other tools, a leather punch. ive. Telephone Accessories is a somewhat A major defect in all the projects is a Anything that touches the telephone useful interim book on do-it-yourself lack of mechanical drawings or pictures. installation in a clinging way is a For­ telephone technology. I hope that later I find it very irritating to read a long eign Attachment. I have heard stories and better illlustrated books on this paragraph of construction steps with no dating many years back, of the persecu­ subject will appear. The book has ab­ drawings to reference. It makes an other­ tions of small town businessmen who solutely no discussion of Blue or Black wise easy project unnecessarily difficult. eked out a living by printing ads on Boxes, or phone phreaking of any kind. plastic telephone directory covers. Is it Unfortunately for computerists, it also The best feature is the use of building has no discussion of modems, cheap block circuits, to which the builder is or otherwise. introduced one at a time in the early projects. The later, more complicated The only proprietary information re­ accessories are often collections of the Note to Software Vendors: We vealed is in chapter one, which is a earlier units. This approach does get out are now reviewing recreational pro­little less than four pages long. There of hand. From a casual inspection of the grams. I f you have software youis a cutaway drawing and schematic Teleswitch, Remote Ear, and Autodialer would like reviewed please send us diagram of a Model 500, standard desk schematics, it seems to me that two iden­ cassettes o f your games and simu­telephone instrument. There is a simple tical circuits are constructed where one lations. Please enclose information but adequate explanation of how it could do the job. on the language, usedthe name of works. the machine the software runs on, I was disappointed to find that some of etc. - R Z Chapter two provides a concise descrip­ the 15 projects were not worthwhile, tion of current tariffs and your optionsso I have divided them into three cate­ concerning them which are: obey and use gories: Useful-8; Useful, but... -4,

52 PEOPLE'S COMPUTERS