Clive Sinclair, who has died aged 81, was one of Britain's most prolific innovators. Known, loved, and recognised for his work in consumer electronics during the late 1970s and early 1980s, he has influenced generations and has gained special recognition and admiration by many electronic and software engineers as well as electronics enthusiasts, collectors, and historians of vintage electronics all over the world.

Largely self-taught, Sinclair began inventing gadgets while he was still at school. His ZX Spectrum computers brought affordable personal computing to the masses and sold in their millions across the world. But his attempt to launch an electric vehicle was not successful, and caused him severe financial problems. 

Clive Marles Sinclair was born on July 30, 1940, in Richmond, Surrey. The young Clive was something of an introvert as a child, preferring the company of adults to that of his own age group.

He also developed a passion for creating gadgets, inspired by a character called 'the Inventor', on the BBC Children's series, Toytown.

Sinclair made a communications system for his hideout in the woods and built miniature radios and amplifiers.

While doing his A-levels, he designed a circuit for a simple radio which he then commissioned a manufacturer to make up into DIY kits.

The kit was sold through magazines such as Practical Wireless, a publication for which he had already written a number of articles.

Keen to return to inventing

Over the following four years, he wrote books on how to construct various electronic devices including radio receivers and transistor circuits.

But while his books sold well, Sinclair was anxious to get back to inventing, and formed his own company, Sinclair Radionics, in 1961.

He produced a number of printed circuit boards and a miniature transistor radio but was unable to raise enough capital to make the business a success.

His first money-making venture came when he heard the Plessey company was discarding new transistors that were not up to scratch.

Having discovered the rejects still worked, Sinclair bought them in bulk, reselling them at a profit and building them into his own products.

Sinclair followed up his kits with fully built hi-fi components and a design for a miniature TV.

He shared the view of Apple's Steve Jobs that design was everything and his products were seen as modern and cutting-edge.

Affordable pocket calculator

In 1972, he designed and released a calculator, the Sinclair Executive. It was the first true pocket calculator and, while technically not particularly advanced, it looked good and, more importantly, was very affordable. It won Design Council awards and was put on show at the Museum of Modern Art in New York. 

But Sinclair's products were proving unreliable and the company faced financial problems. An innovative quartz watch, a sleek black affair, never worked properly and customers returned them in their thousands.

Eventually the company was taken over by Labour's National Enterprise Board and split up. "I'm not a businessman by nature," Sinclair once said, "but we all have to be businesslike in our lives."

Exciting innovations

Sinclair teamed up with Chris Curry who ran a small electronics company called Science of Cambridge. This quickly became Sinclair Research.

In 1980, the ZX80 was launched, a small computer that retailed at less than £100. Enthusiasts could buy it in kit form for £20 less.

It contained many exciting innovations and demonstrated Sinclair's ability to make a product work with the fewest possible number of components.

The follow-up, the ZX81, was still primitive by modern standards. But it would run simple applications and very basic games.

But the relationship between Sinclair and Curry soured following the BBC's decision to run a series on computer literacy, and to badge a machine for the programmes.

The corporation eventually chose Curry's Acorn machine which, while technically more advanced than the ZX81, was much more expensive.

A brief history of the ZX Spectrum

Portuguese assembled ZX Spectrum with plastic keyboard (right) and cassette tape recorder (left). ©LOAD ZX Spectrum Museum

Sinclair hit back with the ZX Spectrum. The big attraction was the colour display and, in its various incarnations, Sinclair sold more than five million machines. 

The ZX Spectrum was the first personal computer accessible to many around the world. It played a significant role in the technological revolution, video game development, and the future of personal computers. 


The Sinclair ZX Spectrum was an eight-bit personal computer first released in the United Kingdom in 1982. It was manufactured in Dundee, Scotland, by Sinclair Research Ltd

Thousands of games were released for the Spectrum during its lifetime. The Text Adventure game was to emerge as one of the most significant genres of the system. The ZX Spectrum was released as eight different models, ranging from 16KB RAM released in 1982 to the ZX Spectrum+3 with 128KB RAM and a built-in floppy disk drive in 1987. 

ZX Spectrum 16K Issue 2 board, Source: ©LOAD ZX Spectrum Museum 

The ZX Spectrum was one of the first mainstream manufactured computers in the UK, similar to its counterpart, the Commodore 64 in the US. The ZX Spectrum has been credited as the machine which launched the UK's information technology industry since companies started to produce software and hardware specific for it. 

The ZX Spectrum was incredibly popular in the domestic market and in the rest of Europe, instantly standing out due to its rubber keyboard, its use of peripherals such as a joystick interface, microdrive, and a printer, as well as cassette tape recorders to load programs and games. 

One of the first models of the Sinclair ZX Spectrum: Issue 1, Source: ©LOAD ZX Spectrum Museum

The ZX Spectrum was basically a black box with a rubber keyboard. Each key was responsible for up to six functions, and the whole keyboard was covered in coded, arcane writing. The computer was fondly nicknamed Speccy. It was affordable and advertised claiming to be half the price of its nearest competitor and more powerful. It was one of the first personal computers to deliver colour graphics and was capable of 256 x 192 pixel resolution when it was plugged into a television. 

Introduced home computers to the masses

The Speccy used audio cassette tapes for loading and saving programs and data. Users had to be very careful to adjust the volume in order to get a program or game to load properly. The ZX Spectrum was able to assemble a library of 23,000 software titles, including popular games such as The Hobbit, Elite, Daley Thompson's Decathlon, Manic Miner, Jet Set Willy, among others equally popular.  

The ZX Spectrum quickly became a symbol of British technological progress and introduced home computers to the masses. It was the third computer manufactured by Sinclair Research after the ZX80 and the ZX81. 

"The ZX Spectrum computer – being the first one to disseminate as a home computer in Europe – sparked the phenomenon of the bedroom coders in the 1980s. Many teenagers soon realised they could be paid to do what they enjoyed most: video games. Many of them moved on into careers in the IT industry,” said João Diogo Ramos.  

"I was one of those bedroom coders in the sense that I started programming on the ZX Spectrum, and I became a computer science guy because of it. A few years later, I even coded some programs for local companies and associations that I was involved with. I was not a coder of games – I never created any famous game or anything like that," he said. Today, Ramos is the co-founder and CEO of a technology company called Retmarker, which focuses on AI software for blindness prevention. 

After the original ZX Spectrum, other models followed including the ZX Spectrum+ (1984) and the ZX Spectrum 128. From there, Amstrad bought the Sinclair computer line and launched the +2, +2A, +2B and +3 models which where even more focused in gaming by incorporating an internal cassette tape recorder or floppy drive.

The Sinclair ZX Spectrum was officially discontinued in 1992.  


Development of an electric vehicle

Following the ZX Spectrum, Sinclair's next big invention was to prove a disaster. Misguidedly, he was beginning to run into financial problems, due to the decision to put his energies, and his cash, into developing an electric vehicle.

Money was poured into research and development and the Sinclair C5 was unveiled in 1985. Buyers were disappointed with its limited range, slow speed and inability to climb hills, while reviewers claimed it was unsafe, something Sinclair strongly denied. 

Sinclair himself later acknowledged the launch had been botched. "The ground was covered in snow and we hadn't realised that the batteries virtually packed up in freezing conditions. It was a crazy time to launch it."

Funded from personal wealth

Sinclair also faced problems with the launch of a new computer, the QL which, despite its innovative design, failed to sell in any great numbers

After failed attempts to raise more cash, Sinclair sold the rights to his computers to Alan Sugar's Amstrad.

Sinclair Research continued to operate as a small research and development company marketing Sinclair's inventions and funded from his own personal wealth. 

He was still fixated by the idea of an electric vehicle and, in 1992, unveiled the Zike, a lightweight electric bike. Like the C5, it failed to sell. A folding bike, which could fit in a suitcase, it also failed when users declared it to be almost impossible to ride.

In 2011, he announced he was working on a new electric vehicle dubbed the X1.

Clive Sinclair was a driving force behind the success of the now ubiquitous personal computer.

He built up a company that earned millions, won a string of awards and was given a knighthood by Margaret Thatcher. But his efforts were dogged by financial problems caused by the failure of his attempts to build an electric vehicle for the masses.

But he remained one of Britain's great innovators who could turn his dreams into reality. "The idea that an inventor can come up with some brilliant idea and somebody else will make it all happen is nonsense," he once said.

"Either you do it yourself or it ain't going to happen."