After the modest but encouraging success of the MK-14 (initiation board with hexadecimal keyboard), Sinclair (at the time Sciences of Cambridge) decided to develop a slightly more advanced computer.
The ZX-80 is regarded as a pioneer system in micro-computing as at the time the only available computers were kits for hobbyists like the MK-14 or more expensive systems intended for education or research such as the Tandy TRS-80 or the Commodore PET.
The ZX-80 inaugurated the transition between the hobbyist world and the consumer electronics by proposing a true computer in its case for less than £100.
Technically, the ZX-80 is not a revolutionary system but is rather the result of a search for economy through the choice of the components, starting with the membrane keyboard, or the RAM memory limited to 1kb. The operating system, the editor and the Basic interpreter fit into the 4kb of the ROM !
The ZX-80 met some success with nearly 70.000 machines sold in less than one year, announcing the future success of the ZX-81 and at the same time the birth of a new major actor in the micro-computers world : Sinclair Computers Ltd.
Malcolm Ramage adds:
The rom in the ZX80 was the basis for the ROM of the ZX81, with a few new commands and enhancements. The Spectrum ROM was based on the ZX81 ROM, with extra commands for colour in basic and new routines in ROM for the new colour screen modes.
Almost all ZX80 BASIC programs can be run on a ZX81 or Spectrum without any modification.
Further information from Watz (Germany):
it was possible to buy a new ROM (50 EUR) and replace it with the old ZX
80's. You got all the function of the ZX 81 - exept the SLOW mode. Everytime something ZX 80/81 moved the screen went black for a moment... Very nasty... Pain for the eyes...
The ZX 81 uses the TV blanking interval for the calculation (so the speed goes down to ca. 25% FAST).
All peripherals must have a very special Sinclair interface, Joystick, printers... I bought a Seikosha GP 50 (unihammer - means one needle making awful noise when printing), and 10 cm broad normal paper, for 204
EUR) with this special interface.
Marty Quire remenbers:
I remember buying the ZX-80 for $99 in "kit" form. When it arrived I put the circuit board into the case & snapped the cover on...that assembled the kit!
One visionary thing about this computer was that keywords of the BASIC interpreter were assigned to the keyboard. It was essentially impossible to type a syntax error, since the keywords wouldn't be added unless they were in the right order.
There were no graphics modes on the ZX-80, but it had graphics characters on the keyboard, displayable with the print command. The character set included a square made up of all 16 combinations of 2x2 fat pixels. This could be used to form a low resolution graphics mode. This character graphics mode formed the basis of the plot commands supported in the ZX-81.
Please consider donating your old computer / videogame system to Old-Computers.com or one of our partners from anywhere in the world (Europe, America, Asia, etc.).
You can run the same Basic programs in ZX81 and Spectrum but ... there will be slower! ZX80 Basic was faster and not only because of the FAST mode, but also because of integer variables and less tokens! $)
Tuesday 18th October 2022
David W. from Ithaca - best to keep your mouth shut and let others believe you are an idiot, than open it and confirm their assumptions. Sir Clive was a visionary, way ahead of his time and only stymied by the technology and attitudes available in the early eighties.
Monday 11th October 2021
Nick Blackburn (Isle of Man, UK)
I bought a new ZX81 in 1983 and it started my interest in computing. Sir Sinclair was the man who gave a lot of people the possiblilty of using and learning a computer. I still own the ZX81, the ZX Spectrum and the Sinclair QL and they are still in working condition !
Tuesday 6th December 2011
Wim Holland (Netherlands)
END OF PRODUCTION
BUILT IN LANGUAGE
Membrane keyboard, 40 keys, 1 SHIFT key
NEC 780C-1 (Z80 compatible)
1 KB, 901 bytes available (upgradable to 64 KB)
4 KB. Can be expended to 8 KB, thereby making it almost a ZX81