[rescue] Mac Appliance

[Dave McGuire]

On August 3, dave at cca.org wrote:
> >  Preemptive multitasking in MacOS isn't something "waiting to be
> >developed" or "lagging behind other OSs".  It was a conscious design
> >decision to implement cooperative multitasking in MacOS instead of
> >preemptive.
> 
> I think it was forced on them by the fact that they were trying to
> maintain compatability with 68000 machine software in the early
> days, no?
> 
> There certainly wasn't a conscious decision to not allow a process
> to request more memory as needed, and force the user to screw with
> memory allocations setting by hand. It was forced on them by needing
> to be compatible with hardware that didn't do VM etc properly.
> 
> If the Mac had been introduced on the 68020 instead of the 68000,
> things would have been very different.

  Preemtptive multitasking has nothing to do with virtual memory.  It
can be implemented on anything (within reason) that has a clock
interrupt...which the Mac certainly does, and did in its earliest
implementation.

        -Dave

-- 
Dave McGuire
Laurel, MD