When requirements for the BBC Microcomputer were developed as part of the BBC Computer Literacy Project, an outline specification was created by an independent consultant, the late John Coll. This specification was then fleshed out by the BBC and given to manufacturers who were interested in tendering for the project. Acorn Computers subsequently won the contract with their innovative design, and the rest, as they say, is history.

Now, whilst many of the machine's features were specified either by Acorn (for their own needs) or by the BBC (as required for the literacy project), some features were specified by BBC engineers entirely for their own requirements. One infamous (and well-documented) example of this was the requirement for linear power supplies to prevent (supposed) interference with broadcast equipment when used in television studios. Since the linear PSUs ran very hot, this requirement was reluctantly dropped by the BBC, and switched-mode PSUs were subsequently used.

I remember reading years ago that other requirements were specified by BBC engineers, but I cannot remember where I read it or what they were. One fairly obvious facility would have been the possibility of providing an external Genlock signal (via an add-in board), so that the video output could be synced with the studio equipment, and such boards were manufactured by various companies. However, I would love to know if any other requirements were specified by BBC engineers for their own purposes.