Prepare yourself for a weekend of wobbly power connectors and Daley Thompson digit-mashing: tomorrow marks the 40th anniversary of the Sinclair ZX Spectrum.

The ZX Spectrum, released on April 23, 1982, was a follow-up to Sinclair’s ZX81. Referred to as the ZX82 or ZX81 Colour during development, the final product arrived with either 16KB or 48KB of RAM (depending on pocket depth) and a case designed by Rick Dickinson, who had previously worked on the ZX81 wedge. Dickinson was also responsible for the ZX Spectrum’s infamous rubber keyboard.

I personally have a lot of respect for the Sinclair team’s single-minded focus on engineering to a target cost – Eben Upton

The BASIC interpreter was stored in ROM and was written by Steve Vickers on contract from Nine Tiles. A prototype ZX Spectrum, formerly in the possession of Nine Tiles, was donated to the Centre for Computing History in 2019. The prototype lacks the Dickinson case and features full-travel keys, but the guts would go on to form the ZX Spectrum found occupying many a family television of the 1980s.

Text took the form of a 32 x 24 column display and graphics had 256 x 192 pixels to play with. Color was problematic; to conserve memory a separate 32 x 24 overlay of 8 x 8 pixels were used, with each block having a foreground and background color. While static color images could work relatively well, the appr