27 Nov
2003
27 Nov
'03
7 a.m.
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
27 Nov
27 Nov
7:33 a.m.
On Thu, 27 Nov 2003, Ian Primus wrote:
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.
ON XT.
On AT (You said AMD K6-2 233!), it is entirely an issue of what
your BIOS does.
(XT uses a BIOS extension ROM on the MFM controller card)
Also, since MFM drives need to be low level formatted
for
a specific controller before they can be high level formatted,
ON XT, there were a lot of mutually incompatible hard disk low level
formats.
ON AT, the format was standardized, and is the same for virtually all
controllers.
I can't
really just format them from Linux.
why not?
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)
If you set the CMOS in an AT to "NO DRIVE", then it will not try to invoke
the MFM hard drive.
IFF your BIOS supports booting from CDROM, then you can. And MOST AT
BIOSes that support booting from CDROM also support letting you choose
boot device.
XT's do NOT support CDROM boot, unless you add an additional ROM (such as
is present on some SCSI controllers for the purpose of booting from a SCSI
hard drive)
For DOS, you need 3.10 or newer if you want CDROM access (the CDROM is
seen as a very Local Area Network, and uses the undocumented network
redirector) (There was an aftermarket driver set for using CDROM with
earlier versions of the OS, but it might not be easy to find)
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
XT or AT? You mentioned "AMD K6-2 233", which would be a very unusual XT!
think I need is a disk with DOS 3.x and debug. I
remember having to use
3.10 or above if you want CDROM access
3.31 or above if you want access to FAT volumes larger than 32M
debug to invoke the built in formatting program on
most hard drive
controllers.
You could write a trivial program (5 bytes) to do a far jump.
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?
For DOS, "Speedstor"
Is there a way to
invoke the card's internal formatter from Linux? It's been a while
You could write a trivial program (5 bytes) to do a far jump.
since I worked with this stuff, can anyone refresh my
memory?
we all have our own "old-timer's disease" issues.
1:33 p.m.
Well, lets see.... if your on a PC, I think if you type at the DOS prompt
c:\> debug c800 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
2:43 p.m.
It was thus said that the Great Curt Vendel once stated:
Well, lets see.... if your on a PC, I think if you type at the DOS prompt
c:\> debug c800 that put you into the MFM controller firmware and you could
perform a low level format of the drive....
If it is MFM and you have DEBUG (which if you have MS-DOS, you probably
do), then:
C:\>debug
-g c800:0005
(and when you get back to the DEBUG prompt "-")
-q
C:\>
If the machine crashes or does something really odd when you type
"g c800:0005" into DEBUG, then you either don't have an MFM drive that can
be low lever formatted, or the MRM ROM has been mapped elsewhere in the
region of $A0000-$EFFFF.
-spc (Okay, I *really* wish this information would leave my brain ... )
28 Nov
28 Nov
12:12 a.m.
Ahhh!!! Now THATS the command, its been a loooooong time since I've run
that command, I knew it was something like that, thanks for given the full
command info, good to remember it exactly now :-)
----- Original Message -----
From: "Sean 'Captain Napalm' Conner" <spc(a)conman.org>
To: <cctalk(a)classiccmp.org>
Sent: Thursday, November 27, 2003 11:43 PM
Subject: Re: Formatting and verifying MFM hard disks
It was thus said that the Great Curt Vendel once
stated:
>
> Well, lets see.... if your on a PC, I think if you type at the DOS
prompt
> c:\> debug c800 that put you into the MFM
controller firmware and you
could
perform a low
level format of the drive....
If it is MFM and you have DEBUG (which if you have MS-DOS, you probably
do), then:
C:\>debug
-g c800:0005
(and when you get back to the DEBUG prompt "-")
-q
C:\>
If the machine crashes or does something really odd when you type
"g c800:0005" into DEBUG, then you either don't have an MFM drive that can
be low lever formatted, or the MRM ROM has been mapped elsewhere in the
region of $A0000-$EFFFF.
-spc (Okay, I *really* wish this information would leave my brain ... )
4:54 a.m.
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27 Nov
27 Nov
3:31 p.m.
c800:5
g.
On Thu, 27 Nov 2003, Curt Vendel wrote:
Well, lets see.... if your on a PC, I think if you
type at the DOS prompt
c:\> debug c800 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
3:33 p.m.
Well, debug g=c800:5 is one command, g=c800:6 works on another type of
controller, and the Xebec controllers are a strange lot that require
several entries to get into it. My memory has failed, so I don't recall
which address goes with what except that the Western Digital controllers
use the :5. On the "newer" versions of debug starting with either Dos
4.x or 5.0, doing a "debug /?" gives a short description of how to use
it, and a ? at the "-" prompt gives simple help. The way I always used
to find out the correct jump to address was to unassemble the address in
question; the correct address will be a jmp instruction.
Gene Buckle wrote:
c800:5
g.
On Thu, 27 Nov 2003, Curt Vendel wrote:
> Well, lets see.... if your on a PC, I think if you type at the DOS prompt
> c:\> debug c800 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
> >
>
>
3:36 p.m.
A five byte file (with an extension of .COM) will do it nicely:
EAh 05h 00h 00h c8h
On Thu, 27 Nov 2003, Gene Buckle wrote:
c800:5
g.
On Thu, 27 Nov 2003, Curt Vendel wrote:
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236
Well, lets see.... if your on a PC, I think if
you type at the DOS prompt
c:\> debug c800 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
7:24 p.m.
so EAh is jump in x86 assembly, eh ? :)
At 09:36 PM 11/27/03, you wrote:
A five byte file (with an extension of .COM) will do it
nicely:
EAh 05h 00h 00h c8h
On Thu, 27 Nov 2003, Gene Buckle wrote:
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236
c800:5
g.
On Thu, 27 Nov 2003, Curt Vendel wrote:
> Well, lets see.... if your on a PC, I think if you type at the DOS
prompt
> c:\> debug c800 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
28 Nov
28 Nov
5:21 a.m.
New subject: X86 jump (was: Formatting and verifying MFM hard disks
Exactly. (JMP C800:0005)
<pedantic>
EAh is a "far jump", 5 bytes, with offset and segment specified.
(Don't forget that intel is Least Significant Byte first)
But also be aware that there are many other jumps in x86:
"near jump", 3 bytes, with offset specified for jumping within
the segment currently specified in CS
"Short jump" or "relative jump", 2 bytes, with a range of 128
bytes from current location
"Conditional jumps", 2 bytes, which are all relative, and
jump or don't jump based on various flags
"CALL"s, both near and far, which push the IP and jump
"Int", which pushes the flags, turns of interrupts, and looks
up far jump destination in the Interrupt Vector Table
By writing such a jump program and putting it into the
boot record of a floppy disk, then you can format drives
for use with other OS's without having to go near
PC/MS-DOS or WINDOZE.
But, if you are going to boot DOS, . . .
DEBUG is the most powerful and useful program that MICROS~1
has ever provided. It is present in EVERY version of
MS-DOS and WINDOZE.
For formatting a drive, it is handier to have than just the
jump program, since you can use it for the jump, use it to
disassemble the ROM (if you have a controller that puts the
routine at a different address), read and write disk sectors
(it assumes a DOS disk), view or edit RAM, or use it to write
ANY program (such as a better OS).
</pedantic>
On Fri, 28 Nov 2003, Geoff Reed wrote:
so EAh is jump in x86 assembly, eh ? :)
At 09:36 PM 11/27/03, you wrote:
>A five byte file (with an extension of .COM) will do it nicely:
>EAh 05h 00h 00h c8h
>On Thu, 27 Nov 2003, Gene Buckle wrote:
> > c800:5
29 Nov
29 Nov
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
1:02 a.m.
New subject: CP/M disk system performance benchmarks
Is anyone aware of a disk performance checker for CP/M, that has some numbers
published to the web? I'm curious to see how this 10Mhz Z80 with an PIO IDE
interface stacks up against DMA systems and such.
--jc
6:47 a.m.
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.
5:41 p.m.
Something in the back of my mind says that "g c800:5" won't work but
"g=c800:5" does the job. IIRC, when I first started to use debug to LLF
the HDs, I wasted a lot of time trying to figure out why things weren't
working when using the "g c800:5" command.
Fred Cisin wrote:
NO!
<pedantic>
C800 is NOT the address! It is the SEGMENT component of a two part
address. But when used as STATED: g C800 , it would NOT cause a branch to
C800:0 as intended! Instead, it would go to OFFSET C800 of the current
segment! xxxx:C800
If you want offset 0 of segment C800, then the command must be: g C800:0
NOT g C800 !!!!!!!!!!
g C800:5 would, indeed, be correct for an offset of 5 within segment C800
BUT "g C800" is NOT going to work.
</pedantic>
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. 
9:13 a.m.
----- Original Message -----
From: "Joe" <rigdonj(a)cfl.rr.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk(a)classiccmp.org>
Sent: Sunday, November 30, 2003 1:32 AM
Subject: Re: Formatting and verifying MFM hard disks
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.
I've got an 8 bit Adaptec RLL card here tha uses C800:ccc to get it started,
all the rest (including other Adaptecs I have) use 5. Still love tht card
though, lot's of extras built into the BIOs format utility :-)
--
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