The Sinclair ZX80 was a home computer brought to market in 1980 by Sinclair Research. It was notable for being the first computer available in the United Kingdom for under a hundred pounds (a pricetag of £99.95, to be exact). It was available in kit form; purchasers had to assemble and solder it together. A ready-built version was also available at a slightly higher cost for those without the skill or inclination to build their own.

The machine was based around the NEC 780C-1 CPU (a Zilog Z80 clone) @ 3.25 MHz, and equipped with 1 KB of static RAM (expandable to 16K), and 4 KB ROM containing the Sinclair BASIC programming language, editor, and "OS". BASIC commands were not entered by spelling them out; instead, the commands were selected rather like they would be on a scientific calculator — each "key" had several different functions activated by use of several modifier (shift) keys.

The video display generator of the ZX80 used very minimalistic hardware plus a combination of software to generate a video signal. As a result of this approach the ZX80 could only generate a picture when it was idle, i.e. waiting for a key to be pressed. When running a BASIC program the display would black out. This prevented moving graphics etc. The later ZX81 improved on this somewhat because it could run 'slow' while creating a video signal, or 'fast' without generating a video signal (used for lengthy calculations).

The machine was mounted in a tiny white plastic case, with a one-piece blue membrane keyboard on the front; it owed its distinctive appearance to industrial designer Rick Dickinson. The entire system was about the size of two paperback books placed beside each other. It kick-started the 80s home computer craze in the UK and was the precursor to the ZX81 and the very successful ZX Spectrum.

The very first Sinclair Computer was the Sinclair MK14 - more info can be found on the web site - http://www.nvg.org/sinclair/computers/mk14/mk14.htm