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From: wyman@blumon.enet.dec.com (Bob Wyman)
Newsgroups: comp.text.tex
Subject: Re: WARNING: 1.2GB disks on VAX; QUESTION: rotate.tex
Message-ID: <20905@shlump.nac.dec.com>
Date: 8 Mar 91 16:45:45 GMT
References: <00945462.A1A74800@BINAH.CC.BRANDEIS.EDU>
Sender: newsdaemon@shlump.nac.dec.com
Reply-To: wyman@blumon.enet.dec.com
Organization: Digital Equipment Corporation
Lines: 38

In article <00945462.A1A74800@BINAH.CC.BRANDEIS.EDU>,
sommer@BINAH.CC.BRANDEIS.EDU writes:
|>First, a warning to people using 1.2 GB disks with VAX/VMS $<$ 5.4. My
|>sys
|>manager has informed me that our disk (where all my latex stuff is
|>located)
|>will be inaccessible until we upgrade to VMS 5.4. It seems that there
|>is a
|>"bug" in the DEC controller software that only counts up to 1.0 GB.
|>It
|>might accidentally overwrite block 1 of $>$ 1 GB disks and wipe out
|>your
|>disk, disk access and all of its contents! 

It isn't a "bug" and it isn't a problem limited to VMS or DEC. The root of the
problem lies in the definition of the SCSI interface standards and the
fact that
there are different "levels" of SCSI. Well, it seems that the SCSI
implemented
on VMS 5.3 and earlier doesn't support disks bigger than 1GB. Newer VMS
version use a different SCSI interface. The same problem exists with the
old
versions of many SCSI controllers.

The important thing is that everyone who is formatting a disk with more than
1GB for use with ANY SCSI controller shipped or sold by ANYONE for use on ANY
computer should ensure that the level of SCSI they are using actually
supports the formatted disk size. If not, you'll have to format the disk
at 1GB or less.
If you try to use more than 1GB, you'll end up with a mess.

Disclaimer: I don't speak for my employer and I'm probably wrong.
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Bob Wyman		       |   Internet:   wyman@blumon.enet.dec.com
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