Subject: Re: small prob w/BT-542B and Viper 2150S
To: None <>
From: Mark P. Gooderum <>
List: current-users
Date: 04/12/1994 10:23:52
> I am relatively sure that the 2150S is a SCSI-1 device.  You might
> check switch settings on your controller to see if it can be placed in
> a SCSI-1 mode.  It may be expecting some other response from target 0.
> You might also see if the tape is properly detected at some id other
> than 0.

What I've found is that most SCSI-2 controllers talk okay to SCSI-1 devices
if there are only SCSI-1 devices on the bus.

If you mix SCSI-1 and SCSI-2 devices with a SCSI-2 controller you can
get reselect errors and other mismash that can render the bus
catatonic.  We had to retire a couple of old SCSI-1 drives for this
reason.  The drives caused problems and were worth less than a seperate
controller would have cost to keep them.

The problem doesn't seem to occur with mixed buses and SCSI-1 controllers
because the problem seems to be only when the SCSI-1 devices start to see
SCSI-2 features actually happen on the bus like extended reselect.