C.O.W.

The Computer Originated World (COW) was used between 18 February 1985 and 16 February 1991. It was later used by the international, commercial television service BBC World Service Television from its launch until 26 January 1995

G.N.A.T.

The clock, known as GNAT (Generator of Network Analogue Time) was designed by a team led by Richard Russell of D&ED. All parameters, including details of the hand movements, are stored in EPROMs. Antialiased hands are generated from this data and superimposed (with an optional shadow) over one of two background images stored in Rec 601 format frame stores.

Electronic TCF

The electronic test card generator was used by the BBC to generate test card known as ‘Test Card F’ replacing the optical generated card from slides. Test cards were used to calibrate television cameras and receivers correctly so that the picture settings are correct, and would be used when no programmes were showing on a channel.

Replica

As I’ve no chance obtaining any of the above, I recreated my own. The rack produces TCF, COW and Teletext,  a clock generator would be nice at some point. All fed into my analogue TV distribution for the TV museum.