SCSI conflict with unity HAL, summary:

Dave Babcook (dbabcook@zeeman.unmc.edu)
Mon, 27 Sep 1999 15:45:38 -0500

Thanks for all the suggestions I received on connecting an ultra-scsi
disk enclosure to a Sparc5/unity (HAL-DMA box) from a while ago.
The usual suspects were rounded up:
-Proper termination of the scsi chain.
-Order of devices in the chain by speed (fastest to slowest).
-Minimizing cable length.
-SCSI target address conflicts, HAL requires target 3, Sparc reserves
target 1 for the internal drive slot.
One suggested SCSI-1 -> SCSI-3 (50 pin to 68 pin) adaptors due to
improper termination with a 50 to 68 pin cable.
A couple suggested adding another SCSI card.

The solution:
Adding a second SCSI card worked(SBus ultra / wide / single-ended card
and cable was about $500).

Thanks for the help,
Dave.

Original post (8/30/99):
In the process of replacing old external disk drives on a Sparc5(sol2.6)
connected to a Unity500 (using the old HAL interlink), I've found what
may be a scsi imcompatibility.
The new disk enclosure uses ultra-scsi connections while the HAL box
uses the old DB-50, scsi-1. Without connecting HAL, all works fine, put
HAL back in the scsi chain, either before or after the disk box, the
sparc5 complains about scsi errors and refuses to initiate the boot
process. I've checked the cables, they are fine.

-- 
Dave Babcook (mailto:dbabcook@zeeman.unmc.edu)