Path: utzoo!attcan!uunet!husc6!mailrus!cwjcc!gatech!mcnc!thorin!clocs!davis
From: davis@clocs.cs.unc.edu (Mark Davis)
Newsgroups: comp.sys.ibm.pc
Subject: More on ST 4096 in PS/2 Model 60
Summary: It may work, but it will be hard.
Keywords: hard disk ps2 mfm bios details
Message-ID: <5286@thorin.cs.unc.edu>
Date: 13 Nov 88 02:25:37 GMT
Sender: news@thorin.cs.unc.edu
Lines: 41


In review: I want to put a new hard disk drive in a PS 2 Mod 60.  The
drive that I would like to use is a Seagate ST4096.  I have learned
some things perhaps of general interest this week.

Thanks to a posting by ogilvie@klipper.cs.vu.nl, I was able to list the
contents of the disk type table from the BIOS ROM.  A 4096 is a type
35 drive.  The ROM has types 1 through 32.  (By the way, since I do
not have MSC 4.0, I translated his program to Turbo Pascal 4.0.)
Result: This will not be an trivial installation.

Again thanks to Paul Ogilvie, (and to the {ms,pc}-dos interrupt
postings from Ralph Brown (ralf@b.gp.cs.cmu.edu)), the interrupt 41H
vector points to the current disk parameters.  However, my PC clone
seems to be using the maximum cylinder and head numbers from the
partition data instead (determined thanks to partitn by
rmarks@ksp.unisys.com (Richard Marks)).  Result: A preformatted,
prepartitioned drive might work.

Additionally, software, such as OnTrack, may provide the required
information to DOS.  If the drive will still not work, I now know that
all I have to do is put in 0H:104H (0H:118H for drive 2) the address to
a table with the proper values.  Not too hard a problem. (:-)  With the
information I now have, I could even write a Turbo Pascal program to
format the disk.  Actually, the problem is not too unmanagable because
this is the second disk, so I can fix a lot of things _after_ the
system has booted.

And if all else fails, Nanook@cup.portal.com tells me you can call
the 4096 a type 32 drive (a Seagate ST4053, IBM's OEM drive) and it
will work, even though only 44 Megabytes will be available.

Result: I am going to buy a ST4096 (preformatted and partitioned with
OnTrack) and try it.  I'll let you know in a couple of weeks how
things progress.

Boy this is fun.  It is a good thing I really dig hardware!  Also,
thanks to all mentioned above and others, it is possible to buy 80 Meg
at $600 instead of 44 Meg at $976.50 (a _real good_ price from IBM).

Thanks - Mark (davis@cs.unc.edu or decvax!mcnc!davis)