you can mostly just create ISO files from the discs.

some original discs, especially games, may have a copy protection scheme (safedisc, securom, etc) that makes them unplayable without being run with the original media, though. there was some software back then that worked pretty well at ‘making backups’ of those discs. also note that some drives (the hardware itself) were better than others at running that software to make them. i haven’t kept up with that stuff in a very long time, so i don’t have a clue what exists today.