Ok, so I'm continuing to fight with this P-133 box. I've now added
an AHA 1540C (? something close to that) and three drives. This is
in addition to the two IDE drives and one IDE cdrom already installed.

I'm having a problem with the 4 gig IBM drive (the newest drive in the
box) where it starts making scary clicking noises and subsequently
the box crashes. 

You know the noise, the sound of a drive head reseeking on a sector,
perhaps reading from a bad sector. Scary stuff, but no messages are
returned on the console. 


Anyway, I can bring the box down with: 
# cd /local/src ; tar -cvvf /dev/null sys

The drive makes clicking noises and then shortly (meaning, before the
tar finishes) the box freezes. I'm dropped into ddb. Here's a ten finger
trace from ddb (partial):

db> trace
cpu_Debugger(c02568a0,c0448e14,c41e207c,c41e2150,c0448e001) at cpu_Debugger+0x4
aha_done(c0448e00,c41e2150,c0454010) at aha_done+0xae
aha_finish_ccbs(c448e00,c0442e60,c444c7f0,c444c7f0,c4460c811)at aha_finish_ccbs+0x142
aha_intr(c0448e00) at aha_intr+0x86
--- interrupt ---

I'm running 1.5_ALPHA2.

Does this sound like a drive problem or a cabling problem? I suspect the
drive is going north (I'm already in the South, so it must be going
north). Would an ailing drive cause the aha driver to hang? 

How about if SCSIDEBUG and AHA_DEBUG (I think that's it) were defined
when the kernel was built?

*sigh*

Thanks all.
-- 
Kevin P. Neal                                http://www.pobox.com/~kpn/

"Nonbelievers found it difficult to defend their position in \ 
    the presense of a working computer." -- a DEC Jensen paper