Booting from SCSI drive at address 1 vs. 0

[Mike McNeill]

lupine!infopiz!mark at uunet.uu.net (Mark Pizzolato 415-369-9366) writes:
>We've got lots of Sun 3/60s and LOTS more SCSI disk drives.  From time to
>time it has been desirable to boot Sun OS 3.x from a SCSI disk whose SCSI
>address is other than 0.  We have been totally unsuccessful with regard to
>achieving this result.  Any ideas?

I had the exact same situation earlier on a standalone 3/60 with 2 SCSI
disks (addrs 0 and 1).  The formula I got for determing unit in b(cntlr,
unit, part) for embedded SCSI disks is unit = SCSI_address << 2.  I leave
it to someone else to explain _why_ this is so...............Mike