In the 1980s, the Doctor's TARDIS had three computer terminals in the console. Two of them had real monitors and the third (in the rare shot that showed it) was just a plastic box with a flat covering (not a curved CRT screen).
Sometimes, they would show the code running on these computers (BBC Micros) for a fraction of a second before the computer program started. Some other "futuristic" computers were shown, running the same (real-world) language.
If you pause an episode, you can see the final few lines of some of these programs, but never the whole code. Do any of these programs still exist in full?
This is a follow-up question from https://retrocomputing.stackexchange.com/questions/2399/what-computer-system-is-this-from-1984-doctor-who which has some more screen-shots!