On Tue, 20 Nov 2001, Andy Ball wrote:

:   TV> ...you may have to disable the cache in the MacOS boot
:     > partition.
:
: Ideally I'd like to go without a MacOS partition, but I
: guess MacOS is not huge, and there are probably some
: advantages to having one.

NetBSD requires booting from MacOS so as to initialize things like the NuBus
reliably.  The Mac ROM is undocumented, and that has been an obstacle to
getting all machines to initialize properly (...whereas having a 5-8MB MacOS
boot partition with a System file is guaranteed to get it Right).

:   TV> No, but the 68030 on the Daystar board has a built-in
:     > PMMU and does not depend on the presence of a 68851.
:
: Does plugging in the upgrade disable the 68851 (if present),
: or does software just 'ignore it'?

The 68030 has a 68851-compatible (well, almost, it's actually more like a
somewhat stripped down 68851) PMMU built onto the chip.  The *hardware*
ignores the on-board 68851 if one is present -- because there's one internal
to the 68030.

Moto bundled PMMU logic inside the CPU with the 68030 and up (...although
there are some MMUless '040s, aka 68EC040, that have pissed off Amiga users
for ages :).

-- 
-- Todd Vierling <tv@wasabisystems.com>  *  Wasabi & NetBSD:  Run with it.
-- CDs, Integration, Embedding, Support -- http://www.wasabisystems.com/