29 Nov
2003
29 Nov
'03
12:32 a.m.
At 10:33 PM 11/27/03 -0500, you wrote:
Well, lets see.... if your on a PC, I think if you
type at the DOS prompt
c:\> debug c800
That's assuming that the controller card is set to the standard address
of C800. C800 is the default for PCs but the cards can be addresses to
different addresses. Checkit is handy for finding the card address. Also
the code doesn't usually start right at the biginning of the ROM. It starts
at an offset of 5 in most controllers so you'd use debug then "g c800:5".
I've seen a couple of controllers that started at 2 and I think I remember
one that started at 10.
Joe
that put you into the MFM controller firmware and you could
perform a low level format of the drive....
Curt
----- Original Message -----
From: "Ian Primus" <ian_primus(a)yahoo.com>
To: "General Posts" <cctalk(a)classiccmp.org>
Sent: Thursday, November 27, 2003 4:00 PM
Subject: Formatting and verifying MFM hard disks
As I have been sorting and cleaning over
Thanksgiving, I decided that I
would build up an extra PC clone for the sole purpose of formatting and
verifying various types of media, such as SCSI, IDE, and MFM hard
drives and 3 1/2 and 5 1/4 floppies. I originally planned on just
tossing an MFM card and SCSI card into an older AMD K6-2 233, and
installing two floppy drives. But, as I got started, I remembered how
the old MFM drive controllers worked, and how they kinda take over the
boot process. Also, since MFM drives need to be low level formatted for
a specific controller before they can be high level formatted, I can't
really just format them from Linux. I found a Seagate card that has a
nice boot screen with a drive formatting utility, but it only handles
eight different Seagate drives. I've got a couple of other old
controllers, none of which have such a nice utility, and all of which
prevent me from booting from CDROM (they intervene before the BIOS
boots from a disk, and when the MFM card can't boot a hard drive, it
tries floppy drives, but it doesn't see the CDROM, and won't return
control of the boot process back to the PC's built in controllers)
Also, in this process, I realized that I can't find my DOS disks! It's
been a long time since I booted DOS, and an even longer time since I've
messed with DOS on XT's, so I don't know where the disks are. What I
think I need is a disk with DOS 3.x and debug. I remember having to use
debug to invoke the built in formatting program on most hard drive
controllers.
Anyway, what I really want to do, is have a computer that would have an
MFM card in it, and be able to work with any MFM drive. I'd also like
to still be able to boot off an IDE hard drive or a CDROM, since I want
to install Linux on an IDE drive on the motherboard's controller, and
use that for high level formatting. I can probably work around that by
having a Lilo bootdisk, and booting that first, then the system could
continue booting from an IDE drive. But, if I did this, what is the
best way to do low level formatting on MFM drives? Is there a way to
invoke the card's internal formatter from Linux? It's been a while
since I worked with this stuff, can anyone refresh my memory?
Thanks!
Ian Primus
ian_primus(a)yahoo.com