Micro Men! Great little TV movie, and really interesting story of the rivalry between UK golden-age home computing giants Sinclair and Acorn (Acorn being the company behind the BBC micro, and also originally the "A" in "ARM").
bbc contracted acorn to produce an educational computer to go hand-in-hand with a tv program. it was a smashing success and made them so much more money than anything else they'd been doing. they birthed arm.
It made them the only money they ever made, but in the end they had to default on payback of 3mil pounds of royalties to BBC thanks to typical 80s mismanagement (oh hi Commodore).