I saw the better GCs were implemented for machines with the 68851 MMU. Later the 68030 had the necessary MMU functionality built in. Both allowed for example Ma

I saw the better GCs were implemented for machines with the 68851 MMU. Later the 68030 had the necessary MMU functionality built in. Both allowed for example Macintosh Common Lisp to have an ephemeral GC, IIRC.