The ZX Spectrum line of personal computers was the most significant commercial success of the Sinclair company. They were cheaper than the Commodore 64 and had a massive library of software and especially games. The Spectrum has a place in computer history folklore as the machine on which many successful tech and internet entrepreneurs of the current era honed their passion as kids of the ’80s. The last version of the Spectrum, the +3, was officially discontinued in 1992.

While Sinclair’s computers and digital devices are well known, the company’s role in pioneering alternative mobility is commonly overlooked. In 1985, Sinclair launched the C5 “electric car”. Despite the moniker and the futuristic look, it was no more than a glorified electric trike. It had a top speed of 15mph (to avoid needing a license to drive it) and an awful range, which could be as low as 10km in cold weather. The vision was there, but the product wasn’t. It might have worked better 30 years later, but then it proved to be the most damning bet Sinclair could have made. The losses from the production and unsold units were so bad that they led the company to sell their computer division to Amstrad.

Almost ten years after the C5, Sinclair came up with another mobility device that today would be all the rage on Kickstarter, the Zeta (Zero-Emission Transport Accessory). When applied to the rear wheel of a regular bike, the battery-carrying box would provide additional propulsion through an internal motor. If you feel like you’ve seen this already, it’s because of a flurry of startups today trying to do the same thing with very similar designs.

Sinclair products seemed often inspired by quirky ideas, drawn from sci-fi movies and the like. Sir Clive himself, for example, was obsessed with producing a miniature television. In the ’60s, even before incorporating his company, Sinclair developed a prototype called Microvision with a small CRT display made by Hitachi. The device worked, but it was impossible to manufacture on a large scale. It took Sinclair ten additional years to bring his mini-TV to market with the TV1A with the Sinclair Radionics company, this time with custom components manufactured in-house and a CRT system tailor-made by Telefunken in Germany. Initially, demand outstripped supply, leading the company to manufacture too many TV1A. In 1979, due to the TV1A successors failing to revive interest in the product line, Sinclair Radionics was dismantled and the rights for the TV1A sold to Binatone, which immediately discontinued the product.

The Cambridge was Sinclair’s first foray into the market of pocket calculators. The first version launched in late 1973 and was followed by a scientific calculator in early 1974. Despite being very popular, the calculators suffered from a near-fatal design flaw that affected the on-off switch and made it impossible to turn the device off after a few days of use.