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 approach resulted in the infamous attribute clash. Rival machines, such as the Commodore 64, did not suffer from the same problem although used a lower multicolor resolution made for blockier graphics.
Ah, the playground discussions that ensued over sprites, peeks, and pokes. Those were the days.
The ZX Spectrum, replete with rubber keyboard, debuted at £125 for the 16KB version and £175 for the 48KB incarnation. A 32KB RAM pack could be plugged into the rear expansion slot of the former, and this writer well remembers the joy of an unexpected reset caused by a wobbly bit of hardware.
Over five million of the Z80A-based devices were sold, and its impact cannot be understated. While over 1.5 million BBC Micros (made by Acorn) may have also been sold during its lifetime, it was the ZX Spectrum that found its way into far more homes across Europe, and its impact continues to resonate in the IT world of today.
Raspberry Pi supremo Eben Upton was more on the Acorn side of things, but recalled the effect of the plastic slab: “As a much more affordable alternative to the Beeb, and with roughly 3x the lifetime sales, the Spectrum probably had a greater role in promoting the accidental route into engineering careers in the ’80s and early ’90s.”
“Lots of people here at Pi Towers had their first exposure to programming on Sinclair hardware,” Upton said, “and I personally have a lot of respect for the Sinclair team’s single-minded focus on engineering to a target cost.”
The original ZX Spectrum enjoyed a relatively short time in the sun, and was discontinued in favor of the functionally identical (but recased with an updated keyboard) ZX Spectrum+ in 1985. Later versions received more RAM and, with the Amstrad takeover, another keyboard update, built-in cassette recorder, and disk drive.
Clones would also crop up from time to time, including the recent (and infamous) ZX Spectrum Vega+. A warm bath of nostalgia is also possible via a variety of on and offline emulators.
Sadly, Sir Clive Sinclair and Rick Dickinson are no longer with us. However, hardware designer Richard Altwasser and Dr Steve Vickers will be on hand at The National Museum of Computing on April 23 for a live and virtual Q&A, preceded by the same with Sir Clive’s son, Crispin.
In the meantime, this seems as good a time as ever to indulge in a little bit of rose-tinted nostalgia. Music by MJ Hibbett and with animation by Rob Manuel. ®