Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!tiamat!bahamut!jim
From: jim@bahamut.fsc.com (James O'Connor)
Newsgroups: comp.unix.xenix
Subject: Re: XENIX 2.2.3 and >1024 h.d. cylinders: possible?
Summary: I use MS-DOS and Xenix 2.3.1 on a 1224 clylinder disk
Keywords: xenix, hard disk, cylinders, ESDI
Message-ID: <245@bahamut.fsc.com>
Date: 15 Sep 89 16:31:27 GMT
References: <13569@well.UUCP> <5806@viscous.sco.COM>
Organization: Filtration Sciences - Chattanooga,TN
Lines: 36

In article <5806@viscous.sco.COM>, rosso@sco.COM (Ross Oliver) writes:
> SCO XENIX 2.2 and above has no problem using disks larger than 1024
> cylinders.  However, if you must share the disk with MS-DOS, you will
> be limited to 1024, because that is as much as MS-DOS understands.

I'm not sure this is exactly true, perhaps a little misleading is a better
term.

I have a CDC ESDI drive with 1224 cylinders.  I used a version of Disk Manager
that supports drives > 1024 clylinders to create
a DOS partition > 200 cylinders (I don't remember how many exactly) so that
the each of the two partitions (DOS and Xenix) were less than 1024
cylinders.

Then I installed DOS on the DOS partition, Xenix on the other and everything
works just dandy.  Granted, when I run FDISK under DOS to look at the
partition table it reports funny numbers, but DIR still reports the 30MB or
so of space in the DOS partition.  No problem for me.

> Another limitation may be your CMOS setup table, which may not have
> a disk entry large enough for your disk.  If that is the case, use the
> entry that is closest, then during XENIX installation (or using the
> dparam(ADM) utility), alter the default disk parameters to match your
> hard disk.

I used the set up and format utilities builtin to the WD controller I have,
and it did this for me (picking the CMOS setup table entry, that is), but it
also did something that Xenix understood, cause when I ran dparam during
the installation, the default number of cylinders came up as 1224.

The only hard part about this whole ordeal was finding the right version of
Disk Manager. :-)
------------- 
James B. O'Connor			Work:	jim@tiamat.fsc.com
Filtration Sciences --			Play:   jim@bahamut.fsc.com
A division of Ahlstrom			UUCP:	uunet!tiamat!jim