Sinclair ZX-81 The ZX-81 was manufactued by Sinclair Research in England, and was the follow-on to his popular ZX-80 computer. The ZX-81 went on to be one of the first home computers to be marketed widely due to it's price, and Sinclair Research came to an agreement with Timex Inc. in the U.S. that allowed Timex to market the computer as the Timex-Sinclair 1000. The ZX-81 had the same wedge shape and 40-key chicklet keyboard, but had only 1k of RAM, which could be expanded by using one of the many memory expansion cartridges available. This particular unit has the original Sinclair 16k RAM pack. There was quite a following for this machine, and there were numerous magazines and newsletters published for it. Sinclair Research went on to produce the popular Spectrum series of computers later on. The ZX-81 was available as both a kit and a preassembled computer. In the end, over one million ZX-81's and Timex/Sinclair 1000's were sold worldwide. There were also various clones of the ZX-81 produced, such as the TK85, which was produced in Brazil.

The machine offered the following video modes (as taken from the ZX-81 FAQ):

There was a chess game, released in 1982 by Artic Computing, that would run in just 1k of RAM on an unexpanded machine. It didn't use graphics and could only play white, but it was quite a programming marvel to be able to fit a chess game into 1k.

Jeff's Computer Haven Home Page