The ZX81 is a home computer, launched by Sinclair Research in 1981, It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and designed to be a low-cost introduction to home computing for the general public. This was the improved version of the ZX80 marketed the previous year. The casing was black, with a membrane keyboard. The definitive appearance of the machine was the work of industrial designer Rick Dickinson. The video output, as in the ZX80, was towards a television by means of a radio frequency modulator, and the programs were read and stored through an ordinary cassette recorder using audio magnetic tapes.