The LCII has a 030, but it was basically a "quick fix" to account for the =
LC's lack of a PMMU.  Because of this the LC and LC II are nearly =
identical (including the MMU.)  Consequently, Apple could have cobbled =
together a hack for the OS, rather than design an MMU that was =
appropraite for the LC II.  The world may never know...

 ------ From: Bill Studenmund, Sat, Apr 20, 1996 ------ 

> I was wondering whether the problems experienced by others had anything =
to
> do with the amount of RAM used in their computers?  According to an 
> information sheet published by Apple, if you put two 4Mb SIMMs into the
> type of LCII with 4Mb RAM soldered to the motherboard, 2Mb of the
> motherboard RAM becomes inaccessible, giving a total of 10Mb usable =
RAM.
> 
> I wonder whether, in this configuration, the LCII has "holes" in its
> physical address space and has to use the PMMU to produce a contiguous
> virtual address space, even when virtual memory is turned off in the 
> "Memory" control panel!  Does anyone know whether this might be the =
cause
> of the problems with running MacBSD in multi-user mode?

Eeewww, groooossss! That sounds sick. I'm not doubting you, I'm just
wondering why Apple would do this?

What kind of CPU does the LCII have, an 020 or an 030? I could understand
this problem if it had an 020 w/o a PMMU, but not if it had 32-bit
addressing and a PMMU.

Take care,

Bill