ma155abl@sdcc7.UUCP (Nick Flor) (12/05/84)
Does the macintosh have any memory management hardware? ie.hardware for multitasking et al. multiprocessing stuff. If not, is there any way, under program control, to interrupt the processor? -Nick Flor
jss@sjuvax.UUCP (Jonathan Shapiro) (12/11/84)
[Aren't you hungry...?] It is my understanding that no memory management hardware exists in the Mac as distributed, but it occurs to me that there may be a 68010 pin for pin replacement for the processor which might be made to do the trick.... Just a thought, I haven't tried it. Bout time somebody started net.micro.mac. Jon Shapiro
mike@smu.UUCP (12/13/84)
The 68010 does not have on board memory management; its main
difference with the 68000 is that the microcode environment can be
saved if a page fault occurs, and thus has restartable instructions.
Even if it could be dropped in in place of the 68000 one would need
additional hardware for the MMU. Could possibly be done through a
piggyback board.
-----------|
| \| My concience is clear, and my spirits are calm
| | And this I go off without prayer book or psalm;
| O Then follow the practice of clever Tom Clinch,
| ||\ Who hung like a hero, and never would flinch
| / \
|\
| \ Mike McNally
| \ mike@csevax.smu
===============rpw3@redwood.UUCP (Rob Warnock) (12/14/84)
+--------------- | It is my understanding that no memory management hardware exists in the | Mac as distributed, but it occurs to me that there may be a 68010 pin for | pin replacement for the processor which might be made to do the trick.... | Jon Shapiro +--------------- Sorry, a 68010 has no memory management in it, either. (For that matter, neither does the 68020.) The '010 indeed IS a pin-for-pin replacement for a 68000, but the ONLY difference as far as memory management goes is that the '010 saves enough stuff on the stack when you get a "bus error" trap (say, from a page fault) that you can re-start (actually, continue) the affected instruction. The 68000 saves SOME stuff, but it's not enough to always unambiguously continue. All of the 680XX processors use an external MMU in order to do virtual memory. (I actually prefer this, as sometimes you want to do it differently than the way the chip maker provided.) Rob Warnock Systems Architecture Consultant UUCP: {ihnp4,ucbvax!dual}!fortune!redwood!rpw3 DDD: (415)572-2607 Envoy: rob.warnock/kingfisher USPS: 510 Trinidad Ln, Foster City, CA 94404
henry@utzoo.UUCP (Henry Spencer) (12/19/84)
> All of the 680XX processors use an external MMU in order to do virtual > memory. (I actually prefer this, as sometimes you want to do it differently > than the way the chip maker provided.) Damn near always, if one substitutes "Motorola" for "the chip maker". -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry