Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: steve@icad.com (Stephen Carr)
Newsgroups: comp.sys.sun
Subject: Problems Installing ExaByte Tape Drive
Keywords: Hardware
Message-ID: <8903312109.AA13307@icad.COM>
Date: 21 Apr 89 09:36:01 GMT
Sender: usenet@rice.edu
Organization: Sun-Spots
Lines: 27
Approved: Sun-Spots@rice.edu
Original-Date: Fri, 31 Mar 89 16:09:40 EST
X-Sun-Spots-Digest: Volume 7, Issue 233, message 13 of 14

I have recently experienced extended problems with the Exabyte tape drive.
We have attached the Exabyte drive to a Sun3/260 with a SCSI-2 (sc) host
adapter.  We are running SunOS 4.0.1 and after completing installation of
the drive, we were unable to access it.  The host adapter would return an
I/O error and the device controller would return a mode select failed
error.  After going through all the standard checks (4.0.1 SCSI patches
removed, replaced X60 backplane adaptor, etc.) we suggested to Exabyte
that they might have a problem with their device driver.

Exabyte responded by examining their device driver software and suggested
that we may have a PROM on the tape drive initialized improperly.  They
described to us the proper sequence for resetting this PROM and (at long
last) we have a functional Exabyte tape drive.  

This PROM can be reset by running adb on /vmunix and querying the variable
st_ex_MX4_23.  After saving a copy of the working kernel, the command
sequence is

	adb -w /vmunix
	st_ex_MX4_23?W 0

The query should return 0x1 and then reset to 0x0.

I'm indebted to both Michael Couch and Bob Wagner of Perfect Byte, Inc.,
for all their help.

					Steve Carr @ Icad