For those of you who can remember cassettes C90’s (90 mins total playing time) had 45 mins of time available this is so you could fit the full two sides of an LP on one side of the tape. So this was always presumed it was 22.5 minutes on each side. It is possible to go slightly longer than this dependant on genre and average program level but the drop off in quality once you go passed this time is not recommended.
