880126b@aucs.AcadiaU.ca (Chris Butler) (01/13/91)
Here's a summary of the responses that I received regarding
whether or not it was possible to operate a 3 1/2" drive (High
density) with an XT. Thanks to all who responded.
-Chris
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From 880506s@AcadiaU.CA
From: 880506s (James R. Skinner)
Yes you can put a high density 3 1/2 drive in your XT but you will
have to check two things first. Can your current floppy controller handle
3.5 drives and if it can't you will have to buy one that can. Secondly and
more importantly does your BOIS support HD 3.5 drives if it does not you
will have to find some new BIOS ROMS that will, which may prove challenging.
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From: ccvr1.cc.ncsu.edu!rdkeys@mcnc.org (Bob Keys)
Subject: Re: 3 1/2" disks on an XT
Yes it is but you will probably have to change your controller card if
it is a real XT. Get a wdgen-2 card, and you should have no problems.
rdkeys@ccvr1.cc.ncsu.edu
P.S. on an AT you only need to change the bios chips to a good late
model clone bios.
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From: ralli@ccadfa.cc.adfa.oz.au (Tony Ralli)
Subject: 3.5 in drive on XT
About six months ago I bought an XT(no-name compatible) with a 5.25 in and a
3.5 in drive as well as the hard disk. It works fine.
The 3.5 in drive is loaded using an external drive device driver and the
system calls it Drive D. For most purposes it will answer to B or D, but
when formatting it is essential to call it D as otherwise you only get
it half density format. Hope that helps.
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From: Lord Orion <klee@uhunix.uhcc.Hawaii.Edu>
Subject: Re: 3 1/2" disks on an XT
Organization: University of Hawaii
No problem, as long as you're using DOS 3.3 or later version.
You would either need to modify your config.sys file, or
purchase a controller that would do similar stuf in
BIOS setting.
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From: FMARTIN@pbs.org
Subject: 3 1/2" disks on an XT
It is possible to run a 3.5 hi-density drive on your XT. I have done this on
my XT and it works great. Heres what you do, it is necessary for you to pull
out your present floppy driver card and replace it with a Super Floppy
controller card. The new controller card will allow you to run 360K, 1.2M
5.25 inch disk drives as well as 3.5 inch 720K or 1.44M drive. A combination
of any two drive is possible. Just taking a quick look in the Computer for
January 91 on Page 649 there is an AD for AMKA INC (TEL) (818) 369 2121
13932 E. Valley BLVD #C, City of Industry, CA.91746.. One of item of concern
is the BIOS ROM chip in your XT computer. On one of the computer I modified,
it was necessary to change the BIOS chip. The Phonenix 2.51 version Of BIOS
works with the Super Floppy controller card. I only Use 3.5 inch High density
Disk on my XT.
w
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From: jcburt@cs.wm.edu (John Burton)
Subject: Re: 3 1/2" disks on an XT
In a word, yes it is possible to install a 3.5" drive in an
IBM-PC/XT. Two things you NEED to do:
1) Make sure your floppy controller can handle the 3.5" drive.
The standard floppy controller supplied with the XT *might*
be able to handle a 3.5" 720kb drive (probably not). It
will NOT handle a 3.5" 1.44mb drive. (I would also recommend
getting the 1.44mb drive instead of the 720kb.). There are
third party controllers available for the high density drives -
I bought one from JDR Microdevices that can handle most common
floppies (360kb, 1.2mb, 720kb, 1.44mb) for about $50.
2) Make sure your OS can handle the drive (you need MSDOS 3.30
or higher for the 1.44mb drive.)
Right now, I have an IBM PC/XT with a 5.25 360kb A: drive and a
3.5" 1.44mb B: drive, using the high density floppy controller I mentioned
and PC-DOS 4.01. The system works wonderfully, I haven't had *any*
problems with it...
If you have a standard floppy controller, you'll probably want to replace
it. Otherwise you'll need an installable device driver (software) and
probably have continual problems...
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From: santeew@cs.uoregon.edu
Subject: Re: 3 1/2" disks on an XT
To answer your question about mounting the 1.44m drive in an XT:
First off, you shouldn't even THINK about mounting a 1.44m drive in an XT
without first investing in a controller card that can do transfers at
500Kb/sec (XT controllers can't), and that you have at LEAST DOS 3.3.
When you have that installed, then THEORETICALLY you can use the new drive.
However, because the XT BIOS is outdated, your system will STILL think that
you are running a 360k drive.
The solution to this is to buy a controller that not only does 500Kb/sec
transfers, but also has a new ROM-BIOS chip on the controller card (~$60).
Then you should be able to use the new drive.
The first thing you NEED, however, is the controller. If you don't get a
controller with a built in ROM-BIOS chip, then you can still get the system
to think that you have a 720k 3.5" (better than 360k, but still poor). To
do that, in your config.sys do one of two things:
DRIVPARM=/D:1 /F:2
or
Device=Driver.Sys
These will "patch" your BIOS to think that you have 720k drives installed,
but there operation can be somewhat confusing.
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--
Chris Butler 880126b@AcadiaU.CA \ The clarity is devastating. But where's
Acadia University, Wolfville, NS \ the ambiguity? Over there in a box.
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Thirty Helens agree...sjo@cci632.UUCP (Steve Owens) (01/31/91)
Thanks for all the prompt responses. I've called Digikey and requested a catalog along with some parts. Should be here in a couple of weeks. Again, many thanks. sjo@op632.cci.com