I found this little gem; a 28 minute video from the East Anglian Film Archive (where else) from their 'Pace Setters' series.
This one's all about Clive Sinclair. Nostalgia isn't what it used to be, so enjoy!
East Anglian Film Archive: The Pace-Setters: Clive Sinclair, 1981
If you like old clips, The Baim Collection has Telly Savalas looks at Aberdeen/Birmingham/Portsmouth. I've love the Birmingham one, where he says "My kind of town". Really? I never knew where I live is well loved by the Hollywood elite.
I found some more videos. Enjoy.
A mashup of Sinclair Research history
BBC's Horizon from 1989: Anatomy of an Inventor (narrated by Paul Vaughan, the definitive voice of 'Horizon')