Sinclair Spectrum ZX81 ZX 81, 16K RAM expansion expansion, retro computer vintage collection, Clive Sinclair, CPU: NEC μPD780C at 3.25 MHz, compatible with Zilog Z80A, ROM: 8 kB, RAM: 1 kB, expandable up to 64 kB, Video: monochrome, text 32 columns × 24 lines, graphics 64 x 48 pixels, Keyboard: QWERTY 40 keys, membrane, Software included in ROM:  Sinclair BASIC, Expansion ports: 1 Expansion port, 1 Antenna (RF connection to TV), 2 Cassette recorder jacks (out and in)

Sinclair ZX81

The Sinclair ZX81 was a low-cost home computer manufactured in the United Kingdom by Sinclair Research. Introduced in 1981 as a successor to the Sinclair ZX80, the Sinclair ZX81 was produced until 1984. The computer was sold by mail order, [...]