22 Jul
2002
22 Jul
'02
10:54 p.m.
At 06:26 PM 7/22/02 -0700, Ethan wrote:
--- Don Maslin <donm(a)cts.com> wrote:
That's correct according to what I've been able to find out.
so the host has to "know" the geometry,
The ACB-4000 Series User Manual is about
1/2" thick, Joe, and is not
partitioned by specific models. But, I see no reason why a regular SCSI
drive could not be installed in lieu of the ACB-4070 and ST-411/506
interface drive. Seems to me that I have gone the other way once.
My experiences with Adaptec bridge controllers is that they don't
support an IDENT packet, meaning that _you_ will have to know the geometry of
the embedded
SCSI drive and tell the host since it will not think to ask the
drive itself.
Hmmm. But how do you tell it the geometry? The User's manual for the system
indicated that there are only two drives that work with this system. I wonder if
that's because the geometry is hard coded into the HD setup program?
Additionally, whatever (low level) formatting software comes with the host
might or not might not work with an embedded drive. Modern drives will
ignore harmful commands, so it's not a risk to the drive, but if there
is a canned procedure for installing the OS (old variants of UNIX come
to mind), it might or might not succeed with an embedded drive if it
was written to expect an ACB-4xxx.
That's what I'm afraid of.
Finally, most Adaptec bridge controllers I know of did support multiple
LUNs. Some SCSI drives won't like being probed for LUNs and may return
a hit for every LUN probed (I've seen that happen with some drives on
an Amiga 3000 which optionally supports multiple LUNs per target ID)
Wonderfull! More problems.
If none of the above differences trip you up, then you should have no
problem using an embedded SCSI drive in place of your ACB-4070.
I think that should have been <B>IF</B>!
Joe
-ethan
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