British inventor Clive Sinclair, creator of the handheld calculator and inexpensive home calculators, has died at the age of 81.

His daughter, Belinda, told The Guardian that he died at his home in London on Thursday morning after a long illness;

"He was a wonderful person, very smart, he was always interested in everything. My daughter and her husband are engineers so he was talking to them about engineering."

The pocket calculator was invented by Sinclair, but he is best known for promoting the home computer, bringing it to British supermarkets at relatively reasonable prices.

Beginnings of adolescence

Sinclair dropped out of school at the age of 17 and worked for 4 years as a technical journalist to raise funds for the founding of Sinclair Radionics.

In the early 1970s, he invented a series of calculators designed to be small and light enough to fit in a pocket, at a time when most models available were large and outdated.

"He wanted to make things small and cheap so people could have access to them," his daughter said.

climb to the top

His first home computer, the ZX80, named after the year it appeared, revolutionized the market, although it was a far cry from today's models.

At £79.95 ($109.95) and £99.95 ($137.47) with accessories, that was about a fifth of the price of other home computers at the time.

His company sold 50,000 units, while his successor, the ZX81, was priced at £69.95, with 250,000 units sold.

Many veterans of the gaming industry started typing programs on the touch keyboard and became addicted to games like 3D Monster Maze and Mazogs.

These two ZX computers made him very rich.

In 2010, Sinclair told the Guardian that "within two or three years we have made a profit of £14m".

In 1982, Sinclair launched the famous computer "K48 ZX Spectrum" (communication sites)

In 1982, Sinclair launched the famous computer "48K ZX Spectrum" with its rubber keys, strange colors and small voice, which won the approval of game developers, and inspired them to create many famous games, including "Jet Set Willy" ), "Horace Goes Skiing", "Chuckie Egg" and many others.

Thanks to these devices, Sinclair became a household name, his products ran out of shelves, and he was awarded a knighthood in 1983.

"Rest in peace, Mr. Sinclair, I loved this computer," Elon Musk, president of Tesla and SpaceX, commented on Twitter on an article about Sinclair describing him as the father of the ZX Spectrum.

RIP, Sir Sinclair.

I loved that computer.

— Elon Musk (@elonmusk) September 16, 2021

thunderous fall

Although the name Sinclair was synonymous with success and invention, it also became associated with one of his least successful inventions, which would cost him money.

He launched the C5, a battery-powered tricycle, in January 1985, forecasting sales of 100,000 units in the first year.

But it faltered, and his company found itself in receivership by October of the same year.

The authorities expressed concerns about the safety of riding a bike that is below the line of sight of other motorists, as well as exposure to the elements, and the following year Sinclair sold his computer business to Amstrad.

C5 battery-powered tricycle was the reason for the bankruptcy of Sinclair (communication sites)

He did not use his inventions

The strange thing about this genius inventor is that he did not use his inventions personally;

His daughter said he never had a pocket calculator as far as she knew, but used a traditional calculator, and told interviewers that he never used a computer or e-mail.

His interests include poetry, marathon running and card games.