|
|
Sinclair ZX80 (1980)
|
The Sinclair ZX80 was a home computer brought to market in 1980 by Sinclair Research of Cambridge, England. It was notable for being the first computer available in the United Kingdom for under a hundred pounds (a pricetag of £99.95, to be exact). It was available in kit form, where purchasers had to assemble and solder it together, and as a ready-built version at a slightly higher cost for those without the skill or inclination to build their own unit. The ZX80 was very popular straight away, and there was for some time a waiting list of several months for either version of the machine.
The machine was based around the NEC µPD780C-1 CPU (a Zilog Z80 clone) @ 3.25 MHz, and equipped with 1 KB of static RAM (expandable to 16KB using a separate memory pack), and 4 KB ROM containing the Sinclair BASIC programming language, editor, and "OS". BASIC commands were not entered by spelling them out; instead, the commands were selected rather like they would be on a scientific calculator - each "key" had several different functions activated by use of several modifier (shift) keys.
Display was over a RF connection to a household television, and simple offline program storage was possible using a cassette recorder. The video display generator of the ZX80 used very minimalist hardware plus a combination of software to generate a video signal. As a result of this approach the ZX80 could only generate a picture when it was idle, i.e. waiting for a key to be pressed. When running a BASIC program the display would, therefore, black out. This prevented moving graphics etc. The later ZX81 improved on this somewhat because it could run in a 'slow' mode while creating a video signal, or in a 'fast' mode without generating a video signal (typically used for lengthy calculations).
The ZX80 1KB memory could be expanded by a 3KB RamPac. There was no upgrade for the integer only arithmetic however, nor the monochrome display.
The machine was mounted in a tiny white plastic case, with a one-piece blue membrane keyboard on the front; it owed its distinctive appearance to industrial designer Rick Dickinson. There were problems with durability, reliability and over-heating. The entire system was about the size of two paperback books placed beside each other. Crude it might have been, but the ZX80 was a true innovator and it kick-started the 1980s home computer craze in the UK. It was superceded by a number of other Sinclair machines, notably the Sinclair ZX81 and the very successful ZX Spectrum. They were compatible with the home computer TK85 made by the brazilian company Microdigital.
|
|
|
|
|
