On Fri, 22 May 1998, David A. Gatwood wrote:

> On Fri, 22 May 1998, Ruschmeyer, John wrote:
> 
> > >        Presumably there is a Macos driver that sets up the environment
> > >        such that the DOS or Win95 can run OK. If you can get something
> > >        in NetBSD to do the same then it should be possible to run DOS
> > >        or Win95 on the card.
> > 
> > I don't own one of these (my latest Mac is a IIfx), but i seem to recall
> > that
> > the problem is the lack of 32-bit drivers for the board.
> > 
> > I vaugely recall that someone was trying to get Linux running on one, but
> > it involved writing a disk driver that would use the PC BIOS (ick!).
> 
> Aren't they doing their accesses to a virtual disk... a file on the MacOS
> side?  Do the drivers that allow Win95 to work actually go through the
> BIOS, or do they have a special means of accessing the files that nobody's
> figured out yet?  :-)

Well, AFAIK, Win95 needs to use 16-bit mode on the DOS card.  (It does on
mine, at least, and mine is the faster of the two made for 68k Macs.)  I'd
guess, from what I've seen, that it's just going through the BIOS the same
way that DOS 6.22 does on that machine.
BTW, it should be noted that we are WAY off topic, since we are now
discussing Win95 on the NetBSD/mac68k list!

> I would think that, while a BIOS solution might work, it'd be dog slow
> (though I could easily be wrong) and depending on the BIOS they used,
> might also have a limit on the maximum drive size usable... or was it
> maximum partition size?  

Well, it is dog slow.  Of course, the computer isn't exactly the latest,
so the drives being used are rarely that large.  Bear in mind that the
internal drive is IDE and limited to 2MB, and it's not much of a problem
for most users.

> I'd think it would be much better to disassemble the '95 drivers and see
> what tricks they use to access the data... because I'd bet they're a lot
> faster and more flexible than a BIOS workaround.  Alternately, don't most
> of the systems with the DOS cards have DMA SCSI?  By any chance could the
> drivers take advantage of that to control the SCSI hardware directly
> without totally munging things for the Mac-side?  Just a thought.

Like I said, they don't have any tricks...  The newer DOS Compatibility
cards (now called PC Compatibility cards) actually run Win95
semi-reliably, but not so those that mac68k-ers might be using.  At any
rate, BIOS slowness or not, the Linux-on-a-DOS-card project sounds
interesting, bearing in mind that it's Linux.

	-Seth Miller
	 with apologies for the rapid veer off-topic