>> Today I picked up a 3/110 that has a 4mb RAM card and the si0 SCSI
>> card.  If I take the card and drop it into the /260 then the /260
>> has a fit.  [...]

>> I assume this means that both cards are trying to be at the same
>> address?

Almost certainly, especially since the default address for si0 is the
same as the default address for sc0.

>> How do I set the jumpers on the backplane?

Both out.  One of them has to be out when the card interrupts, the
other when the card uses DMA (or rather, when they are capable of doing
so; whether they actually do or not is a matter for the OS).  Both the
sc and si do both, so both jumpers should be out.

>> How do I jumper the si0 card to not conflict with the sc0?

There's a bank of switches.  As I recall, looking at the default
address for si0 (0xff200000, drop the leading ff) and the switch banks,
it was pretty obvious what was what and how to tweak them to get it at
0xff204000 instead.  Next time I'm at home I can pull the si from one
of my machines and post something more definitive.  (0xff204000 is what
the NetBSD/sun3 GENERIC config puts si1 at.)

> According to [a Sun FAQ] only a single scsi adaptor is supported,

Well, yeah, Sun never considered any multiple-SCSI-controller
configurations "supported".  But by this point, no -3/260 configuration
at all is "supported"; the Sun-3 has been dropped.  (I think.  If you
want to be sure, call Sun and ask.)  In any case, two si cards in a
single -3/260 has worked for me. :-)

> Have you tried just replacing the sc card with the si?  Some si cards
> supported both internal and external connections...

The si and sc are both adapter-based cards, with the guts of the card
plugged into a something-to-VME adapter.  What controls whether it's an
si or sc is the "guts" card; what controls whether the SCSI chain is
internal (on P2, must be in slot 7 (I think)) or external (DD-50 on the
backplane) is which adapter is used.  You can freely mix-and-match
adapters and "guts", at least in my experience.

					der Mouse

			       mouse@rodents.montreal.qc.ca
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