Home computing pioneer Sir Clive Sinclair has died at the age of 81.
His daughter, Belinda Sinclair, said the man behind the Spectrum died at his home in London on Thursday morning.
In 1980, Sir Clive launched the first cheaper consumer computer, the Sinclair, costing less than £100 ($138).
The multimillionaire entrepreneur’s company launched the ZX models in a decade when personal computer use boomed.
Sinclair's company became the first in the world to sell more than a million computers.
Ms Sinclair revealed 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.
Speaking to The Guardian, she 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 also explored new technology in the realm 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.
Born in 1940, Sinclair left school at the age of 17, becoming a technical journalist writing specialist manuals.
At age 22, he formed Sinclair Radionics, his first company, making mail-order radio kits, including the smallest transistor radio in the world.
Later in life, he pioneered the pocket calculator and was heralded as an “electronics wizard”.
Other ventures included expansions into digital watches and the development of the world’s smallest television set.
It was with another company, Sinclair Research, that Sir Clive found his home computing success as he faced off against international competition.
The ZX 81 computer launched in 1981, with half a million sold, and was followed up by more powerful models.
Film director Edgar Wright paid tribute to Sinclair's computing achievements on Twitter.
He tweeted: “For someone whose first glimpses of a brave new world were the terrifying graphics of 3D Monster Maze on the ZX81, I’d like to salute tech pioneer Sir Clive Sinclair.
“He made 21st-century dreams feel possible. Will bash away on the rubber keys of a Spectrum in your honour. RIP.”
Tom Watson, former deputy leader of the Labour Party, tweeted: “This man changed the course of my life.
“And arguably, the digital age for us in the UK started with the Sinclair ZX80, when thousands of kids learnt to code using 1k of RAM. For us, the Spectrum was like a Rolls-Royce with 48k.”
Sinclair was knighted in the birthday honours in 1983.
His daughter, who had helped care for him in his final years, told the BBC that he was a devoted grandfather to her three children.