Subject: Re: Madhatter & Q900
To: The Great Mr. Kurtz [David A. Gatwood] <davagatw@mars.utm.edu>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 04/21/1997 11:28:19
> 
> On Mon, 21 Apr 1997, Tommy Tarka wrote:
> 
> > > >	gets as far as:
> > > >		boot device: sd0
> > > >		root on sd0a swap on sd0b
> > > >
> > > >then it hangs.  I haven't tried a serial console yet....although that's a
> > > >project for next week.
> 
> Here's a weird thought.  Since the serial ports aren't supported on that
> machine, you might try telling the booter to disable them (w/ the
> appletalk network option, which sets them to 0 baud).  I don't know if it
> can disable both or just one, since my booter's not current.

NB: It's a LocalTalk option, not AppleTalk. You can have AppleTalk w/o
LocalTalk (netatalk at present), and LocalTalk w/o AppleTalk (a NetBSD
machine hooked up to a LocalTalk net).

The problem is that this option doesn't disable the serial ports, it just
sets the baud rate ridiculously low. I don't think it'll help here.

There was some talk of making the IOP's run in serial compatability
mode. If we could program them to do that, then we're set.

> > > Ummm, doesn't the Q900 have the IOPs (input output processors, like the
> > > IIfx and Q950) which Apple so nicely failed to document?
> 
> Didn't somebody say (a few weeks ago) that the quiadras shared IOP's w/
> the PowerMacs?  Two words: Mach Kernel.  The IIfx, as I understand it, is
> different, and I may have misunderstood about the Quadras, too....  Bill?
> Colin?

I'm not sure, but if they did, they are wrong. The 900 and 950's IOP's
are shared only with the IIfx. If we got the IOP's supported for one,
we'd probably get them all.

The AV Quadras (660 & 840) share I/O support w/ the PowerPC's. The CHRP
documents would help for them. In a few months, I'd love to get a used
660AV and play w/ the serial ports. :-) But the current drivers will
work for now (on the 660 and 840).

Take care,

Bill