Sinclair ZX80

The ZX80 (1980) was Sinclair’s first computer built on the single-ULA design philosophy that defined the whole ZX line — and, at under £100, the first computer at that price point sold in Europe. It shares the ZX81’s cramped 1 KB of RAM and touch-membrane keyboard, but without the ZX81’s later FAST/SLOW timing trick: the display simply goes blank whenever the machine is computing anything, since the CPU has to generate the video signal itself. A year later Sinclair refined the same basic design into the ZX81.

Reference photo: Wikimedia Commons (“ZX80.jpg” by Daniel Ryde), CC BY-SA 3.0 / GFDL.