some miscellaneous AUX questions

[Jim Jagielski]

In article <128126 at tiger.oxy.edu> wirehead at oxy.edu (David J. Harr) writes:
>><hansm at duteca8.et.tudelft.nl (Hans Mulder) asks if he needs an MMU for A/UX
>
>The good news is that a 68030 accelerator board for a MacII will work just
>fine with A/UX, the bad news is that you will have to get the SuperDrive ROM
>upgrade in order for the ROMs to recognize the MMU on the '030. So, you can
>buy an MMu for about $150-$200, or you can go ahead and buy an accelerator
>for your Mac and then fork out the $185 it will take to got the ROM upgrade.
>


Actually, it depends on the Accelerator card. For example, the Dove Marathon
REQUIRES the ROM upgrade and the PMMU chip NOT installed (that is, you must
have the original MacII AMU chip installed) else it gets confused.

The Daystar boards DON'T require the ROM upgrade since they supply a chip
that plugs into the AMU/PMMU socket... I guess this takes care of convincing
the Mac that the MMU capability is in the CPU... this chip may be some-kinda
"loopback" circuit that directs instructions back to the CPU :/

The Siclone cards also don't require the ROM upgrade... it's better to check
with the card's manufacturer.

If you plan on upgrading to the SuperDrive OR using the 4MB RAM SIMMS, then
you NEED the ROM upgrade, whether you're running a 68030 or a 68020.

Whew :)
--
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                                 =:^)
           Jim Jagielski                    NASA/GSFC, Code 711.1
     jim at jagubox.gsfc.nasa.gov               Greenbelt, MD 20771

"Kilimanjaro is a pretty tricky climb. Most of it's up, until you reach
 the very, very top, and then it tends to slope away rather sharply."