Home computer pioneer Sir Clive Sinclair was asked to cast his mind back to the early years of his inventing career today - after being called to give evidence at a fraud trial.

The 73-year-old scientist spent around 10 minutes in the witness box at Birmingham Crown Court, answering questions about his role in developing the ZX80 and ZX81 in the late 1970s and early 1980s.

Wearing a dark blue suit, Sir Clive denied having ever met 50-year-old David Griffiths, who is accused of claiming to have worked with the inventor in the past.

Griffiths, of Oreton, Shropshire, and 49-year-old Simon Drew, of Rye, West Sussex, both deny a total of 34 charges of fraud linked to animated film projects.

Sir Clive, who arrived at a court in a taxi, told jurors the ZX80 and ZX81 had been developed by himself three other people based in Cambridge.

Responding to questions from prosecution counsel Malcolm Morse, Sir Clive said of the ZX81: "The hardware was designed by a team of four of us.

"I was really responsible for the architecture of the computer - the architecture being the overall concept of the computer and how it worked."

Mr Morse then asked the inventor: "Was one of (the design team) called David Griffiths?"

Sir Clive, who told the jury that he had never to his knowledge met anyone named David Griffiths, replied: "No he was not."

During his brief testimony, Sir Clive received an apology from Griffiths' counsel for being "dragged" to court to give "a bit of a history lesson" to the jury.

After answering questions concerning Sinclair Research's laboratories, Sir Clive laughed along with jurors as Drew's barrister revealed that his wife still possesses a functioning ZX81.

Patrick Harrington QC told the Sinclair Research owner: "I have no questions for you, Sir Clive, but I thought you might like to know that my wife still has a ZX81 and it still works."

Sir Clive replied: "Thank you very much."