km@mathcs.emory.edu (02/25/90)
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.