Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!math.lsa.umich.edu!emv
From: km@mathcs.emory.edu
Newsgroups: comp.periphs.scsi
Subject: [comp.sys.sun] SCSI-3 on Sun 4/280
Message-ID: <11151@stag.math.lsa.umich.edu>
Date: 25 Feb 90 01:55:44 GMT
Sender: news@math.lsa.umich.edu
Reply-To: km@mathcs.emory.edu
Followup-To: comp.sys.sun,comp.periphs.scsi
Lines: 38

Original-posting-by: km@mathcs.emory.edu
Original-subject: SCSI-3 on Sun 4/280
Reposted-by: emv@math.lsa.umich.edu (Edward Vielmetti)

Recently I posted a note asking for feedback on using a Sun SCSI-3 board
on a Sun 4/280. The information I had from Sun field service was that only
SCSI-2 was supported.

As many people (running SCSI-3) told me this is not the case. Our field
service rep based the advise on the following information:

            ****************

 Here is a list of scsi adapters from our FE Handbook :

The 501-1045 is a Sun-2 SCSI. The 501-1236 is a Sun-3 SCSI.

Sun 3x2 Adapter Assemblies With SCSI Host Adapter

    Assy #     Adapter #   P2 A&C   SCSI Host   SCSI Bus
    501-1167   500-1059    yes      501-1045    external
    501-1149   500-1059    yes      501-1045    internal
    501-1138   500-1220    no       501-1045    external
    501-1170   500-1059    yes      501-1236    internal
    501-1217   500-1220    no       501-1236    external

The difference lies in if you need rows A & C connected on the P2 bus.

            ****************

I wanted an adaptor to support an external SCSI disk. The field service
rep assumed I also would want P2 A&C access, which then limited the answer
to the 501-1167 SCSI-2 board.

In practice, I think I have no need for P2 A&C, which means the SCSI-3
501-1217 would meet my need. My understanding is that P2 A&C brings the
peripheral side of the SCSI adaptor out on Suns extended VME for the
convenience of internally mounted SCSI peripherals.