Comment by aeturnum

I mean....it will compile and return the same AST on the OS and hardware from 30 years ago. But if you want to get the same result today on modern hardware / software you may discover you need to make some changes (or rather people have been making little changes for 30 years to ensure you can still get the same AST). Generally software has either had little bits and bobs added and removed to keep it relevant or its fallen away and been forgotten.