Tandy Model I,II,III,4,16100,1000,3000,PC4
Total Page：16
File Type：pdf, Size：1020Kb
At last a computer for those who know NOTHING about computers! • • • and it costs only $800 Later this month, Tandy Electronics is releasing its new TRS-80 computers which were suitable for microcomputer in Australia. Designed especially for use in the their needs were too expensive. At around $20,000 they have been beyond home, small business and school, and by people with no previous most small businesses and self- experience, the TRS-80 is a complete computer system offering employed people, while even the facilities until now found only in systems costing around $15-20,000 schools have only been able to afford a — yet it will be selling for only $799.95. A few weeks ago EA's Editor few, generally purchased by state Jim Rowe was invited by Tandy to review the first sample TRS-80 education departments and "passed around" for a few days at a time system brought to Australia, and here is his report: between individual schools. But the TRS-80 and other small low - When Tandy Electronics invited me professional. cost microcomputer systems now star- to review the advance sample of the In the meantime for a much wider ting to appear on the market are going Australian version of their TRS-80 group of potential users like school to change all \this. For the first time microcomputer system, I was naturally students and teachers, small businesses, since computers were developed in the very interested. Like most microcom- and self-employed people like doctors, late 1940's, almost anyone who needs a puter enthusiasts I had already read solicitors and plumbers the only small computer is going to be able to buy about the TRS-80, which created quite a stir in the USA when it was released there in August last year. Of course the TRS-80 was not the first small computer system to appear. Hobby-type computers have been available for a couple of years now thanks to the development of large- scale integrated circuits (LSIs) like the microprocessor — which squeezes all of the circuitry of a digital computer's "central processor unit" or CPU into a single tiny chip of silicon. But hobby computers have generally been sold as do-it-yourself kits, and often for individual parts of a computer rather than for a complete system. Not only that, but the literature and program "software" supplied with hob- by computer systems is often, quite sparse, and suitable only for 'people having considerable experience with computers. Needless to say, this makes hobby computers mainly of interest to the mad keen amateur and off-duty Low in cost, Tandy's TRS-80 microcom- puter is • ideal for small businesses, schools, and budget balancing. 10 ELECTRONICS Australia, March, 1978 A closeup of the complete TRS-80 system. The computer itself is inside the one and learn to use it themselves to keyboard unit; the TV monitor and cassette recorder are quite conventional. As solve their own problems. you can see, there are no highly technical controls. I don't think it is exaggerating to say that the TRS-80 is the first of a new breed of "personal" computers, which The computer unit itself measures costly systems. It handles both integer are already starting to work the real only 425 x 208 x 90 mm, and looks just and floating-point arithmetic, with a computer revolution. No longer will like the keyboard unit of a video ter- numeric range of approximately 10 -38 computers remain the impersonal, minal. However under the professional to 1038 and a resolution of 7 digits (6 dis- kmited-use machines restricted by their 53-key keyboard is a complete played) in floating-point mode. Up to nigh cost to the world of big business microcomputer, based on the Zilog Z- 26 numeric variables may be used, and huge corporations. From now on 80 microprocessor. Along with the Z-80 together with two string variables of up their benefits are going to flow directly in the basic TRS-80 computer unit are to 16 characters, and a single dimen- ;into the "grassroots" level of our socie- 4096 words ("4k") of dynamic read- sioned array. (If this doesn't mean . with machines of various sizes used write memory (RAM), another 4k anything to you at this stage, don't personally and as an everyday tool by words of read-only memory (ROM), all worry. Keep reading, but just skim over an one who can benefit from them. the circuitry required for the video dis- the next paragraph or two. ..) But enough of this general introduc- play interfacing, and the cassette tape If you're familiar with BASIC non. Having looked briefly at the con- interfacing circuitry. language commands, the TRS-80 :ext in which the new "personal com- Resident in the ROM, and ready to features all the standard commands: bowers" have appeared, let's now take a spring into life as soon as power is NEW, LIST, RUN, CONT, REM, LET (op- closer look at the Tandy TRS-80 — the applied to the TRS-80 is an interpreter tional), FOR-NEXT-STEP, GOSUB- 'first of the low-cost systems to actually program for "Level 1 BASIC" program- RETURN, STOP, END, GOTO, IF-THEN, reach the consumer market. ming language. Without going into the INPUT, ON-GOTO, ON-GOSUB, Lnlike many of the hobby com- technicalities, this means that the TRS- PRINT, DATA,READ and RESTORE. puters, the TRS-80 comes not as a kit, 80 can be programmed in the easy-to- Many of these can be abbreviated, to but as a completely assembled as tested learn BASIC language developed at contract program size if desired. There system which is ready to run. It com- Dartmouth College in the USA, rather are also the standard mathematical prises four units: the computer itself, than in the harder-to-grasp and more functions, relational operators, logic built into an input keyboard unit; a tedious machine language or assembly functions and functions including INT, .-Tigh-resolution video monitor, with a languages used on many hobby com- TAB, ABS, RND and MEM (memory 3km-diagonal display; a cassette tape puters. size). recorder, for program and data The Level-1 BASIC offered on the There are four other commands con- storage; and a small mains-stepdown TRS-80 is virtually the same as that cerned with the cassette tape recorder. :ransformer unit. available on much larger and more CSAVE is for saving programs on tape, ELECTRONICS Australia, March, 1978 11 A computerfor h,ase rho know NOTHING about computers • * orki:e CLOAD is for loading them back After working through the User's than 6MHz for crisp, sharp displays. The into the computer. Similarly INPUT Manual, you'll be able to drive the TRS- incoming video signal is isolated from attic PRINT are for exchanging data 80 like an expert, and be ready for the cathode ray tube circuitry via an twetAeen the computer and tape. almost anything! opto-coupler, to ensure that the com- But perhaps the most exciting thing And it's amazing just what the TRS-80 puter cannot be damaged by arc-overs about the TRS-80 is that the video dis- is capable of doing. Tandy itself is going within the tube. The monitor is a stan- 714'6 has a graphics facility, allowing to market a series of softwarepackages dard video monitor, and has a 75-ohm graphs, simple diagrams and other (with the programs recorded on input; it can be used not only with the cork to be generated on the video cassettes), for some of the more ob- TRS-80 but with any source of of stan- moven along with alphanumeric infor- vious applications: primary school dard video signals. The TRS-80 video in- Inapon — and all programmable in maths tuition, personal finance terface is built into the computer unit 1111A5I,C. The commands to facilitate this management, games of chance, kitchen itself, and only standard composite CLS (clear screen), SET(X,Y) (turn on menu filing, scientific and engineering video passes out to the monitor. Other graphical element at location x, y calculations, music theory tuition, monitors may thus be used, although ace x has a value from 0 to 127 and y general ledger, and inventory control. they must have high bandwidth for e 4alue from 0 to 47); RESET(X,Y); But there's almost no limit to the adequate resolution. POI\T(X,Y) (which is a function retur- programs you can write yourself, to Similarly the cassette recorder which "aux a value of 1 if the point x,y is on, or take advantage of the TRS-80's con- forms part of the TRS-80 system is a Ik a is off); and PRINT AT Z (which siderable facilities. standard audio recorder. The computer Alas.'s placement of alphanumeric in- Of course, being a relatively small unit controls it semi-automatically, via iorrnation at any desired position on machine, the basic "4k" version of the an inbuilt relay which connects to the lite display). TRS-80 has its limitations. With this in "remote" jack on the recorder. The tf some of the foregoing details of the A5IC commands and functions bruriided by the TRS-80 don't mean !moth to you, don't assume that the cor7puter is only for those who already understand the jargon. Nothing could be further from the truth. In fact Tandy Ificas assumed that a buyer of the TRS-80 oper:'t have even heard of BASIC before, and is coming to it without any prvor knowledge at all.