Sinclair ZX81 – the second computer of the Sinclair Research Ltd company, released in 1981. It was an improved version of the previous model, the ZX80 and also had backward compatibility with it. As a predecessor it was shipped as a kit for home assembly or as assembled device. The price of ZX81 was £50 and £70 respectively. The reduction of the price was achieved by using the ULA chips instead of the small logic devices. Sinclair has sold in total nearly half a million computers.
In the United States Sinclair ZX81 was manufactured by Timex Corporation under the name Timex Sinclair 1000 (TS 1000). It has been adapted for use with the NTSC television standard and had two the amount of RAM. Sinclair ZX81 production was ceased in 1983. For many well-known game developers for ZX Spectrum computer, ZX81 was the first one they saw and where they began to write their own programs. Among them, Oliver Twins, Raffaele Cecco, Dave Rogers, Clive Townsend, Nick Bruty, David M. Webb, David Perry and others. Brazilian company Microdigital Electronica produced ZX81 clone called TK-83, with 2KB of RAM and a joystick interface.
Starting with the Sinclair ZX81, in all computers of the Sinclair Research Company has been applied ULA technology that allows to reduce the price of the device. Motherboard of the previous model contain 21 chips, whereas ZX81 was built with only 4 or 5 chips, CPU, ROM, ULA (Ferranti production) and static RAM on one or two chips (one 1024x8 or two 1024x4).
Sinclair ZX81 was a very popular computer among gamers at that time. Therefore, lots of games were developed specifically for this platform. Today, these games are still interesting and fun and you can easily play them without having Sinclair ZX81 computer. Simply use the emulator software and download for free any ZX81 roms games from the list on this page.