On Sat, 9 Oct 1999 squeegy-macbsd@squeegy.org wrote:

> I am trying to connect another scsi device to my mac SE/30
> I am trying to connect a 410mb power drive.  the drive works fine
> with my duo running 7.5.5.  My SE/30 is running the same OS on the
> small partition, but when i try to boot with the drive connected to it
> it  just hangs.  it never begins the boot process.  why would the same 
> drive behave differently on two different macs?

If you mean it hangs when booting NetBSD-mac68k, it could be a million
things, I'd imagine.  No idea there.

If you mean that it hangs with a grey screen at power on or something
similar, it's probably a termination problem.  Some machines are more
sensitive to termination problems than others.  Not sure why... maybe the
trace length on the motherboard or some difference in the electrical
stability of some component or... who knows.  Anyway, check the
termination.

I've also seen this sort of problem if a SCSI cable is just plain bad.  It
will work under certain circumstances, giving mostly successful results on
one machine, although usually with random crashes under MacOS) and not
being able to boot with it attached to another machine.  Thus, you should
also consider replacing the cable and see if that helps.

Finally, that symptom can be caused by two SCSI drives having the same
SCSI ID.  In some cases, a machine will boot and ignore one of the drives.
The MESH controller used on PCI PowerMacs is a good example of this.  Not
sure how that works, but it appears to....  However, other SCSI hardware
will just plain refuse to deal with a bus with an ID conflict.  And, of
course, if you were moving this drive from one machine to another, it's
quite possible (likely, even) that you'd have another device at a given ID
on one machine and not on the other....  :-)

Hope that helps.


Later,
David