[Si-Co]

Excuse my ignorance here, but what type of machines and “tapes” would have been used by the TV companies around the 1980s era to play testcard, interval (eg ITV Schools, Channel 4 break fillers) and breakdown music. The tracks and tapes themselves have often been referred to but I’ve no idea how they were played to air. I’ve seen examples of tracks played directly from LP, which would work during a short breakdown, but what about during longer junctions and trade test transmissions?