Re: SCSI Boot Error?

[dempson@actrix.gen.nz (David Empson)]

John L. Graham <fl332@cleveland.Freenet.Edu> wrote:

> I'm troubleshooting a problem with a Q-Drive and an Apple High Speed SCSI
> Card and I'm a bit stumped. The card and drive are from a IIe that's
> performed flawlessly for years. All of a sudden we're getting the message
> "SCSI BBOT ERROR" when we try to boot the drive. I put the card and drive
> on a GS to take a look at it and it seems to work okay. You can access
> data and programs from the Finder.

Did you actually try booting from it, or were you booting from another
drive?

I haven't delved into the HS SCSI card's firwmare, but I'd guess that a
"SCSI BOOT ERROR" indicates any of the following problems:

1. A damaged partition map.  It might be something as simple as a flag
bit indicating that it is readable or bootable.  (I don't know if the HS
SCSI card firmware obeys these bits.)  Was the drive even partitioned?

2. A damaged boot sector in the first partition, e.g. the signature byte
at offset zero doesn't contain $01.  I'd expect Deliverance to detect
and repair this (though I can't be sure of this).

3. A termination problem.  One possibility would be if the drive was
supplying termination power, but its fuse on the TERMPWR line has blown
for some reason.  The termination would not work reliably any more,
unless another drive was connected at the same time which was correctly
providing termination power.

-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand