Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
ZX80
The Sinclair ZX80 is a home computer launched on 29 January 1980 by Science of Cambridge Ltd. (later to be better known as Sinclair Research). It was one of the first computers available in the United Kingdom for less than a hundred pounds. It was available in kit form for £79.95, where purchasers had to assemble and solder it together, and as a ready-built version at £99.95.
The ZX80 was advertised as the first personal computer for under £100 and received praise for its value and documentation. However, it faced criticism for screen blanking during program execution, small RAM size, and the keyboard design. It was very popular straight away, and for some time there was a waiting list of several months for either version of the machine.
The ZX80 was named after the Z80 processor with the 'X' meaning "the mystery ingredient".
Internally, the machine was designed by Jim Westwood around a Z80 central processing unit with a clock speed of 3.25 MHz, and is equipped with 1 KB of static RAM and 4 KB of read-only memory (ROM). It has no sound output.
The ZX80 is designed around readily available TTL ICs, without any custom chips; the only proprietary technology is the firmware.
The machine is mounted in a small white plastic case, with a one-piece blue membrane keyboard on the front. There were problems with durability, reliability and overheating (despite appearances, the black stripes visible on the top rear of the case are merely cosmetic, and are not ventilation slots).
Video output is black-and-white, character-based. However, the ZX80 character set includes some simple block-based graphics glyphs, allowing basic graphics to be accomplished, with some effort. One advantage to using monochrome video is that different colour broadcast standards (e.g. PAL, SECAM) simply were not an issue when the system was sold outside the UK. The NTSC standard was different enough that it required a hardware change (including an extra diode).
Display was over an 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 minimal hardware plus a combination of software to generate a video signal. (Some say[weasel words] this was an idea popularised by Don Lancaster in his 1978 book The TV Cheap Video Cookbook and his "TV Typewriter". However, that design does not involve a microprocessor for video generation, and is not similar to the ZX80 in other aspects either. The ZX80 and ZX81 also employ very specific traits of the Z80 processor.)
Hub AI
ZX80 AI simulator
(@ZX80_simulator)
ZX80
The Sinclair ZX80 is a home computer launched on 29 January 1980 by Science of Cambridge Ltd. (later to be better known as Sinclair Research). It was one of the first computers available in the United Kingdom for less than a hundred pounds. It was available in kit form for £79.95, where purchasers had to assemble and solder it together, and as a ready-built version at £99.95.
The ZX80 was advertised as the first personal computer for under £100 and received praise for its value and documentation. However, it faced criticism for screen blanking during program execution, small RAM size, and the keyboard design. It was very popular straight away, and for some time there was a waiting list of several months for either version of the machine.
The ZX80 was named after the Z80 processor with the 'X' meaning "the mystery ingredient".
Internally, the machine was designed by Jim Westwood around a Z80 central processing unit with a clock speed of 3.25 MHz, and is equipped with 1 KB of static RAM and 4 KB of read-only memory (ROM). It has no sound output.
The ZX80 is designed around readily available TTL ICs, without any custom chips; the only proprietary technology is the firmware.
The machine is mounted in a small white plastic case, with a one-piece blue membrane keyboard on the front. There were problems with durability, reliability and overheating (despite appearances, the black stripes visible on the top rear of the case are merely cosmetic, and are not ventilation slots).
Video output is black-and-white, character-based. However, the ZX80 character set includes some simple block-based graphics glyphs, allowing basic graphics to be accomplished, with some effort. One advantage to using monochrome video is that different colour broadcast standards (e.g. PAL, SECAM) simply were not an issue when the system was sold outside the UK. The NTSC standard was different enough that it required a hardware change (including an extra diode).
Display was over an 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 minimal hardware plus a combination of software to generate a video signal. (Some say[weasel words] this was an idea popularised by Don Lancaster in his 1978 book The TV Cheap Video Cookbook and his "TV Typewriter". However, that design does not involve a microprocessor for video generation, and is not similar to the ZX80 in other aspects either. The ZX80 and ZX81 also employ very specific traits of the Z80 processor.)