On Aug 7, 2025, at 5:43 PM, Paul Koning <[email protected]> wrote: > > A very important enhancement in the 68010 is that you could take a page fault > and handle it in a way that allowed virtual memory systems. Apollo Computer > built some of the first workstation products, with VM, using a pair of 68000s > running in lockstep, to make page faults work with a chip that didn't handle > it right.
That’s why I said: >> The 68010 did change exception stack frame layout and added a register and a >> couple supervisor-only instructions to meet Popek & Goldberg virtualization >> requirements All instructions need to be restartable to meet the Popek & Goldberg requirements, whether they trap due to a privilege violation or a bus error. Memory is just one of the things that can be virtualized once a system meeds the requirements. -- Chris
