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From: krowitz%richter@UMIX.CC.UMICH.EDU (David Krowitz)
Newsgroups: comp.sys.apollo
Subject: Re:  Apollo SCSI and tape drives
Message-ID: <9005311341.AA05392@richter.mit.edu>
Date: 31 May 90 13:41:20 GMT
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The answer to your question is yes and no. You can run an Exabyte tape
drive off of the SCSI port of a Western Digital WD7000 multifuntion disk
controller (the controller shipped with the large disks on the DN3500/4500)
if you use Omniback. Omniback is the only Apollo program which uses the
new tape I/O library which includes support for the 8mm drive. All of
the other programs (wbak/rbak, tar, dd, etc) use the older tape library
which only supports cartridge tapes and 9-track magtapes.

Workstation Solutions sells the Exabyte drive bundled with a tape I/O
library which will allow wbak/rbak, tar, dd, etc. to use the 8mm drive
as if it were a 9-track magtape. Their library works with the WD7000
controller on the DN3500/4500, with the SCSI port of the DN2500, and
with a separate controller board which they supply for DN3000/4000's
or for DN3500/4500' which do not already have a WD7000. I've tested
all three variations, and they all seem to work ok.

I have no idea why Apollo's support for the 8mm drive has been so
poor. Basically, unless you only want to run Omniback you are forced
to go to a 3rd party vendor. I would not expect this situation to
get any better in the future. At our last New England ADUS local
user's group meeting the HP peripherals presentation was really
pushing 4mm DAT's as a superior alternative to 8mm drives. Frankly,
I don't see much advantage to the 4mm drives unless you have a 
completely new tape backup/archive program to go with it ... but
the HP rep did not seem very responsive to the fact that the current
installed base is all 8mm drives.


 -- David Krowitz

krowitz@richter.mit.edu   (18.83.0.109)
krowitz%richter.mit.edu@eddie.mit.edu
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