Adding a 3rd party SCSI disk to an rs6000

[Tim Brown]

I have been following this for a while.  I have also been talking to
seagate engineers and experimenting.  Here is what works and why.

I don't know about all scsi devices but the seagate drives require
that the scsi topology be on one leg.  In other words you can't have a
situation where the seagete (wren) is hooked up externally *and* have
an IBM drive internally.  It is an either or situation.  

I hooked mine up by capping or terminating the internal edge connector
and hooking up *all* of my scsi devices externally.  This works fine.

Some caveats:

1. If you do like I did (cap internal connector) the card supports
seven(7) external devices, else two internal and two external.

2. Set your external scsi drive address to zero (0) or one (1) and it
can be the boot disk at install time.

3. If you already have one internal scsi, you must either forfiet a
tape or cdrom OR wire the Wren up as an internal scsi chained with the
first.

I have proved this both at IBM on one of thier demo systems and on our
system.  At IBM I hooked my WrenV up as another internal drive or
second scsi (they had one in there).

On my system, all scsi devices are external.  CDROM, Tape and WrenV.
I have room and addresses for four (4) more drives!


-- 
Tim Brown            |
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