From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Sun, 13 Jul 1997 17:12:08 -0400
From: geoff@plan9.bell-labs.com geoff@plan9.bell-labs.com
Subject: SCSI woes.
Topicbox-Message-UUID: 5d09190a-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19970713211208.eY838yw55ZJQi04-nto6D0MyJ0uY_T_fYeDZdr7gqZo@z>

I have used the AHA1542CP in several machines; I think I've used it
with the Seagate ST12400N and on another occasion with bigger disks
and 9pcfs.  I don't think I've ever seen your symptoms.  You've got
the 1542 i/o port base set to 0x330, the drive's SCSI id set to 0, and
the bus is terminated correctly (if you've only a single SCSI device,
it should have termination enabled internally or have a SCSI
terminator attached)?  b.com will only look at 0x330 for a SCSI host
adapter.  Have you configured the adapter with Adaptec's `SCSISelect'
program, accessible at boot time with control-a?  SCSISelect should
also be able to probe the disk a little, as a sanity check.

Disabling plug-and-play also disables the 1542CP's BIOS (because it
then effectively becomes a 1542CF but the BIOS is for the 1542CP and
the versions don't match), which I don't believe is needed if you only
run Plan 9.

An unrelated potential problem is that the 1542 has a built-in floppy
controller that may need to be disabled (switch 5) if your system
already has one.

The SEE ALSO section of scuzz(8) is a good place to find out where to
learn more about SCSI; there's also a newer book called something like
`The SCSI and IDE Standards' that's quite good.  A quick introduction,
geared to FreeBSD, can be found through
`http://www.freebsd.org/handbook/handbook.html' (it's
`http://www.freebsd.org/handbook/handbook127.html' today, but they
keep renumbering it).