The ZX80, launched in 1980, is widely regarded as having founded the British home computer market. Although it is primitive compared even to the ZX81 and Spectrum, it laid the pattern for virtually every Sinclair machine to come. It was the smallest and cheapest computer in the world and was one of the first aimed at the home user, as opposed to the hobbyist. It's less well known now than the later Sinclair machines, probably because it sold "only" around 70,000, as against millions of ZX81s and Spectrums.

Nonetheless, the ZX80 marked a key point in the development of Sinclair and the British home computer market, and is now a rare collector's item. But, ironically, its development - and that of its successors - was essentially an accident: Sinclair was seeking money to develop one of his pet ideas, a flat-screen TV, and realised that home computers offered the best prospect for making a "quick buck".