MMU Suport In SoftMac

About Mini vMac and all other 68k emulators, including SoftMac, Executor, and MESS.

Moderators: Cat_7, Ronald P. Regensburg

PPC68k

Post by PPC68k »

MMU definition
A hardware device or circuit that supports virtual memory and paging by translating virtual addresses into physical addresses.

paging definition

MMU monitors accesses to memory and splits each address into a page number (the most significant bits) and an offset within that page (the lower bits). It then looks up the page number in its page table. The page may be marked as paged in or paged out.

That is why BasiliskII has no virtual memory and also why ram doubler won't run on it.
As Ram Doubler is an improved manager of virtual memory it also needs a MMU.

The MMU emulation is one of the hard things to do in PPC emulation.

The intel chips (486 and onwards) all have a MMU with virtual paging built into the hardware (windows uses it).

One of the things a PPC (or a mac 68k MMU) emulator would have to do is map all MacOS application memory calls (they involve using the PPC or 68k MMU) to the intel hardware MMU.
Guest

Re: 6MB ROMs

Post by Guest »

Dead Bob wrote:Sorry, something sent me to an error page each time.
Dude. You posted a dupe. And then you posted another one.
Post Reply