From: garyrich@qdeck.com (Gary Rich)
Subject: Re: Tape Backups (NovaBack)
Organization: Quarterdeck Office Systems, Santa Monica CA
Date: Thu, 10 Dec 1992 20:43:48 GMT

In article <Bz0AxE.Lt7@SSD.intel.com> jkearns@ssd.intel.com (Jerry Kearns) writes:
>In article <1992Dec8.233255.58@vms.huji.ac.il>, gilf@vms.huji.ac.il (Gil Freund) writes:
>|> In article <theall.45.723776731@gdalsrv.sas.upenn.edu>, theall@gdalsrv.sas.upenn.edu (George A. Theall) writes:
>|> > In article <1992Dec6.195814.61724@cc.usu.edu> jrd@cc.usu.edu (Joe Doupnik) writes:
>|> >>In article <1992Dec7.015446.10181@panix.com>, bergman@panix.com (Mark Bergman) writes:
>|> >>> After calling _many_ tape drive manufacturers in search of a
>|> >>> DV compatible tape drive/controller/software, I may have
>|> >>> found a solution. One manufacturer reccommended NovaBack
>|> >>> controller software, by NovaStor.
>|> >>----------------
>|> >>	Recommended. It works fine here and has saved several of my NetWare
>|> >>file servers. Interface is good, performance is very good, and it really
>|> >>does the backup/restore business. I use it with an Archive DAT drive and
>|> >>Adaptec 1542B.
>|> >
>|> >   Over Fidonet a Quarterdeck support person recently reported that QOS has
>|> > found a way to use CMS Jumbo tape drives under DV. Here's a portion of his
>|> > message:
>|> >
>|> > 			----- snip, snip, snip -----
>|> >      Date: 11-27D92
>|> >      From: MARK HOCKINGS
>|> >   Subject: DESQVIEW, DVX AND JUMBO TAPE
>|> > -----------------------------------------------------------------------------
>|> > Well, we've been doing some testing with these puppies, and it appears
>|> > we have some good news. Seems that they do work under DV just fine if
>|> > you start DV with the parameter:
>|> >
>|> > /HW:0E:L
>|> >
>|> > This works with the tape backup running of the Floppy controller. We've
>|> > tested it on several machines and it works fine. Unattended backups work
>|> > as well. Same goes for running under DESQview/X.
>|> >
>|> > Mark.
>|> >
>|> > ... QOS Tech Support
>|> > 			----- snip, snip, snip -----
>|> >
>|> > I've also seen reports of folks having luck when using those drives along
>|> > with the optional controller card from CMS.
>|> >
>|> >
>|> > George
>|> > ---
>|> > theall@gdalsrv.sas.upenn.edu                    Social Science Computing
>|> > theall@ssdc.sas.upenn.edu                       University of Pennsylvania
>|> 
>|> Will this work only with the manufacturers software, or also with commercial
>|> software such as PC/Tools of The Norton Backup?
>|> 
>|> --
>|> ==========================================================================
>|> Gil Freund                                             GILF@VMS.HUJI.AC.IL
>|> ==========================================================================
>
>This solution doesn't work for me under DV/X !  When I first tried it, I got a message
>saying I needed to add "DMA=32" to my QEMM line, but my system still locks up hard after
>making that change.
>
>Jerry

All right.  Let me tell you what the above line is doing.  I think that 
will make it a bit more clear.  /hw:0E:L is telling DV or DVX to give the
floppy disk interrupt to the last program that hooked it.  In the example,
the tape backup is one of the ones that "piggybacks" off of the floppy
disk controller.  Normally DV/DVX will give the floppy interrupt to the
program that is "in DOS" at any given moment.  The default behaviour is
"A Good Thing".  I'm sure that "L"ing it will make this type of tape drive
behave better, since they are using the floppy int in a way similar to the
way a comm program uses the comm port IRQ#, which is approprite to give
to the last program that hooked it.  I would expect very squirelly 
behaviour if you tried to run a program from a floppy while the tape
drive had hooked int 0Eh, since the program would go through DOS to get 
at the drive.  If this worked for me, I'd only use it in DV/DVX sessions
where I was going to use the tape drive, and I would stay far away from the 
floppies.

##################	WARNING	#####################
DO NOT PLAY WITH THE HW PARAMETERS!!!!!  They are like dynamite in the
wrong hands.  With the judicious use of this parameter I can make your
computer into a melted pile of plastic that smells like dead fish!  I know
it can be tempting to fiddle with these.  Trust me, don't do it!  Our 
Developers know how to use it.  Mark knows how to use it. I know how to use it.
I can think of a handfull of others....

YOU HAVE BEEN WARNED!!
#######################################################

OK, I feel better now....

If the above works with the OEM backup software it should work equally well
with commercial backup software.

Obviously, this will not help tape drives that don't daisy chain off the 
floppy controller.

A program that generates a DMA warning is a different thing.  If you get
one of these, I would suggest not fooling around and go straight to
DMA=128 on the QEMM line.


-- 
: Gary Rich : garyrich@qdeck.com
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Newsgroups: comp.os.msdos.desqview