On Fri, 6 Dec 2002, Kevin Diggs wrote:

>     Can I infer from your statements that the bus in my 8600 is running at 5
> MHz under MacOS? Or is it set to 10 by default because in this model the mesh
> is internal only?

You should avoid inferring anything from that comment.  I'd assume that
the default is being set up by open firmware, which on an 8600 should
default to 10 MHz, I think, but don't quote me on that.  Feel free
to probe the registers and find out, though....  As for what Mac OS does
to the chip after it takes control... that's anybody's guess.


David


> 
> > On Fri, 6 Dec 2002, Andy Ball wrote:
> >
> > >    BS> The on board mesh SCSI connects to the internal ZIP
> > >      > drive if it has one.  The internal ATA is ATA-3,
> > >      > 16.6MB/s.
> > >
> > > Iomega don't seem to make internal SCSI Zip drives any more,
> > > which strikes me as a shame. That said, I loved the way that
> > > NetBSD 'just worked' with my USB Zip drive :-)
> >
> > It's worth noting that many beige G3 machines had an ATA zip.  I'm not
> > sure when they changed over, but there was a definite changeover.  After
> > that, the onboard SCSI was only used for external devices.
> >
> > It's also probably worth noting that the MESH controller was configured to
> > run at slow external bus speeds, but that its clock speed can be changed
> > in software to improve performance if the bus is clean enough to handle
> > it.  The Linux driver has either a run time or compile time option, I
> > forget which.  Scary.
> >
> > Later,
> > David
> >
> > ---------------------------------------------------------------------
> > David A. Gatwood                                dgatwood@gatwood.net
> > Developer Docs Writer                             dgatwood@apple.com
> > Apple Computer                                  dgatwood@mklinux.org
> >
> >                     Check out my weekly web comic:
> >                      http://www.techmagazine.org
> 

---------------------------------------------------------------------
David A. Gatwood                                dgatwood@gatwood.net
Developer Docs Writer                             dgatwood@apple.com
Apple Computer                                  dgatwood@mklinux.org

                    Check out my weekly web comic:
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