From: ridgwad@atlantis.CS.ORST.EDU (Dean Ridgway)
Newsgroups: comp.sys.amiga.hardware
Subject: Help on CDC Wren hard drive.
Summary: CDC Wren hard drive not reliable.
Date: 11 Dec 92 21:37:19 GMT
Article-I.D.: leela.1992Dec11.213719.9329
Followup-To: comp.sys.amiga.hardware
Organization: Computer Science Outreach Services - Oregon State University

Hello people, a friend of mine has several 5.25" format full-height CRC WREN
94171-344 300 meg hard drives and I am interested in buying one to put on my
A500.  We don't have any documentation on these drives, no jumper settings etc.
All we know is they were taken out of a SUN.

The drive is currently being powered off a 200 watt IBM AT supply.  I am using
a Supra SCSI interface with Series III v3.8a software.  I have my Quantum P40S
configured as SCSI 0, the CDC as SCSI 1 and a QIC tape streamer as SCSI 4.
Operation of the Quantum and tape streamer remain normal.  The tape drive is
internally terminated and I have pulled the resistor packs off both the
Quantum and the CDC.

The CDC low/high level formats with no problem and shows only a few sectors
mapped out as bad (right now its set as one big partition).  Quarterback tools
v1.3b can't find any bad sectors after a high level format.

The problems occur during usage, occasionally the drive throws up the system
"write error" requestor.  Pressing RETRY once will continue and the file will
CRC the same as the source.  During reads from the drive it will occasionally
put up the "read error" system requestor, pressing RETRY does no good and you
eventually have to CANCEL (well I gave up after about seven tries).  These
errors appear to be totally random, as reading/writing the same file again
either completes with no problems or produces DIFFERENT bad sector numbers.

Sometimes along with the read/write error the drive will emit a loud WHANG
sound.  Once this happens, that sector will ALWAYS be bad after that and any
furthur attempts to read/write that file produces another WHANG and error at
the exact same sector number.  This does not appear to be physical media damage
because the error can be fixed by doing a "quick" format (until it happens
again somewhere else).

Since these are older drives, I have played with the mountlist MAXTRANSFER
parameter as I thought thats what was wrong (drive getting too much data at
once) but this does not appear to change anything.

Someone once mentioned to me that older drives have a jumper for "partity
enabled" and if that is jumpered when no other devices on the SCSI bus has it
set there will be all kinds of weird problems.  Could this be it?  I rather
doubt it since my friend is having similar experiances with trying one of
these on his 386 box where the CDC as the only SCSI device.

Any suggestions or are these drives just plain worn out?

There are three different sets of jumpers.  Anyone have the jumper sheet for
this?  Looking at the back of the drive...

                                 ;;;::   || PPPPP

 TTTTT   =============================   |: TTTTT

 = 50-pin SCSI connector
 P power connector
 T 16-pin DIP SCSI terminator pack
 : jumper (open)
 | jumper (closed)
 ; These three jumpers are for the SCSI-ID

ANY help at all would be appreciated.

Dean Ridgway | FidoNet 1:357/1.103 | InterNet ridgwad@jacobs.cs.orst.edu
	     | CIS 73225,512       |          ridgwad@atlantis.cs.orst.edu