All this preservation should have some standardisation.
There was a recent article that described the recent
Doomsday book ( only 15 years ago!) could`t be read:
because there was a lack of tape machines that could read the original BBC code.
It was only with the advent of a BBC emulator that the files could slowly ( with the few working tape machines ) be re-written to Cd's.
:-D
Anyway here`s a token link for the Retros
:-D
http://nthdimension.emuunlim.com/