[SunRescue] Second SCSI (diff) not recognized?

[Loomis, Rip]

All--
I've played with SBus add-in cards before and
never had any problems, but I have one now with
an SBus wide differential SCSI + Ethernet card.
It's installed in a system that I can't easily pop
the top off of, so I don't have the exact part #.

I'm relatively confident in the card (purchased
from a co-worker), and its onboard Ethernet is
recognized as le1...but under Solaris 2.5.1 the
SCSI part of the card is apparently "seen"
(shows up in dmesg output as "esp1") but then
is inaccessible.

I have several IBM external differential drives that
showed up today and finally allowed me to try
to test the card, but so far no joy.  I've tried two
different SCSI cables, boot -r, and other variants--
but it's as though the silly thing isn't really
there or supported.  Under /dev/rdsk the c1* entries
didn't get added after the re-configure boot, and
under the /devices tree I see the espdma entry
for esp0 but nothing for esp1.

Any hints?  If I find a part number, is there any
chance that this thing wants a version of Solaris
either earlier or later than 2.5.1?  Are there actually
separate drivers or some such that I need to load?
Even Antares cards have always just been recognized
by the Solaris kernel, but I'm at a loss.

It's possible that all the hard disks are toast, I suppose--
but it seems unlikely.  Ideally even though the silly
thing doesn't show up with probe-scsi-all, there should
be *some* simple way to verify that it's there and that
it really *is* just a hard disk/cable problem.

Hints or help welcomed--

  --Rip