Computing pioneer Sir Clive Sinclair who had links to St Ives dies aged 81

His daughter Belinda Sinclair told the Guardian that the pocket calculator trailblazer and the brains behind the Spectrum home computers died at his home in London on Thursday morning.

Sir Clive Sinclair launched the first affordable consumer computer in 1980, costing less than £100.

The world's first pocket calculator, the Sinclair Executive, was made in St Ives in 1972 by Sir Clive Sinclair in his factory in the Old Mill.

Sir Clive Sinclair, founder and chairman of Sinclair Research, watches 8-year-old Joe Challands enjoying being the first owner of a Sinclair 2-inch pocket television. (Image: PA Archive/PA Images)

He provided employment for 150 workers at the factory during the 1970s.

Sinclair became the first company in the world to sell more than a million computers, making Sir Clive's surname a household word.

Ms Sinclair told the BBC that her father had cancer for more than a decade and was still working on inventions up until last week "because that was what he loved doing".

"He was inventive and imaginative and for him it was exciting and an adventure, it was his passion," she told the broadcaster.

Business mogul Lord Sugar paid tribute to his "good friend and competitor" on Twitter, writing: "What a guy he kicked started consumer electronics in the UK with his amplifier kits then calculators, watches mini TV and of course the Sinclair ZX. Not to forget his quirky electric car. R.I.P Friend."

Others used Twitter to share their memories of Sir Clive's computer creations.

Broadcaster Professor Brian Cox said: "The ZX81 was my introduction to computing and I loved it! Started out with a 1k version and eventually saved up for a 16k ram pack - thank you Clive!"

Speaking to the Guardian, Ms Sinclair said: "It was the ideas, the challenge, that he found exciting.

"He'd come up with an idea and say, 'There's no point in asking if someone wants it, because they can't imagine it."'

A man of diverse interests, Sir Clive's projects also saw him explore new technology in the worlds of television and cars.

One ill-fated initiative was the Sinclair C5 vehicle, an electric tricycle heralded as the future of eco-friendly transport but which turned out to be an expensive flop.