unbootable plextor cd, buslogic controller

[freebsd at dreamchaser.org]

I've been suffering with this for years, and finally decided I should
resolve it...

   buslogic BT-930 (flashpoint lt) pci scsi adapter
   plextor 12Plex PX-12CSi CD rom

I can't boot from the CD.

I have the scsi controller bios (ver 1.31p) set to enable booting from
CD, and have the jumper on the CD for "Block", which the manual says
"Leave this jumper off, unless you are working in the unix environment
and want to boot from your CD-ROM drive." I've tried it both ways.

I've tried booting with the CD jumper both ways, to no effect.

I originally had the CD scsi ID set to 6, with the HDDs at 0 and 1.
That would, I thought, explain booting only from HDD-0, assuming it
was bootable.  However, I recently changed the IDs so the CD is 0
and the HDDs are 1 and 2, with no better luck.

I'm now using an Asus A7N8X-E mobo, which appears to have bios boot
settings only for SCSI in general, and not a particular type of SCSI
device.  It does have settings for CD-ROM and HDD-0,1,2,3 but as
nearly as I can tell those all assume EIDE devices.

Any ideas why I can't boot from the CD?'

Thanks,

Gary