My CS teacher told me that in the Good-old-times(tm) they archived not just external libraries; but a copy of the compiler with the source code for any given re

My CS teacher told me that in the Good-old-times(tm) they archived not just external libraries; but a copy of the compiler with the source code for any given release. Still wonder how they actually did it because storage was expensive as hell. Probably everything was backed up on a tape.