I think that switching into 32-bit mode can be done fairly easily.  In
fact, we may even be able to use the ROM to do it.  Of course, the ROM
routines themselves may not all be 32-bit clean, but that shouldn't
matter for us if we don't switch into 32-bit mode until after we make
what use we need to of the ROMs.

> Apparently the IIx, IIcx and SE/30 all used exactly the same ROMs with an
> extra kludge on the SE/30 to make it think the internal video was in a NuBus
> slot. If this is the case then the number of models really reduces to just
> the II and IIx.

This is pretty much the case.

> I presume the II and IIx actually have the HFS code in the ROMs, (I know the
> MacPlus did not but that was still able to boot from an HFS volume).
> 
> Do Macs boot by loading a boot/IPL record (apart from the driver) from a
> Volume or do they boot by using their HFS ROM code to read the system file?

I'm not sure.  According to IM V, they can boot off of boot blocks.  I'm
not sure that anyone's ever tried.  No version of A/UX that I ever saw
actually tried that--they also used a MacOS tool.

A lot of people suggest replacing the Finder with a booter and booting off
a tiny HFS volume, but I think that should be the back-up plan...

-allen