Low-level an IDE
Gabriel Stephens Jones
comp.sys.ibm.pc.hardware.* FAQs to no avail. What is the debug command to
low-level format an IDE drive?
E-mail appreciated (gjo...@buster.eng.ua.edu), as I'll be out of town for
the next week. THanks for any replies.
Gabe
--
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
Launchpad is an experimental internet BBS. The views of its users do not
necessarily represent those of UNC-Chapel Hill, OIT, or the SysOps.
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
Peter Moss
>
>This is probably a big-time FAQ, but I checked all the
>comp.sys.ibm.pc.hardware.* FAQs to no avail. What is the debug command to
>low-level format an IDE drive?
There is no FAQ because this is a factory procedure.
There is no debug command to format an AT IDE drive. :-)
There are some IDE controllers that have format capability (it will
have a bios). If you have one of these the controller docs will be
the place to look. It will not actually format the drive :-)
Why do you want to format it?
Peter
--
Peter Moss
E-mail: pm...@yoda.alt.za
Thomas Adams
> comp.sys.ibm.pc.hardware.* FAQs to no avail. What is the debug command to
> low-level format an IDE drive?
Pardon? I don't think it's that easy. I assume you have to get a format
utility written by the drive's manufacturer. (You know why you shouldn't
low level format an IDE drive, don't you?)
I have one for Seagate drives, would that be helpful?
-tom
--
Just 'cause you've got the power that don't mean you've got the right.
Thomas Adams Dortmund Germany
t...@cat.ping.de
Gabriel Stephens Jones
Peter Moss <pm...@yoda.alt.za> wrote:
>There is no FAQ because this is a factory procedure.
>There is no debug command to format an AT IDE drive. :-)
Oh. Well. I thought I remembered seeing something about a go command
("g=address") that would do this.
>There are some IDE controllers that have format capability (it will
>have a bios). If you have one of these the controller docs will be
>the place to look. It will not actually format the drive :-)
Yeah, I think my friend's PC can do this.
>Why do you want to format it?
The above-mentioned friend was having (serious) problems with her hard
drive. Bad sectors left & right. It's an old 100MB clunker. Track 0
finally went bad and she couldn't boot anymore. I've tried every recovery
technique I know, but have just resigned it to be a doorstop. Thought it
would be cool to try to low-level it, though, since I've always been told
you aren't supposed to do that. :-) I had borrowed the drive to put in
my PC to try to fix it, and wanted to attempt to low-level it there. Now
that I think of it, though, seems like her PC had an option somewhere to
do so--guess I'll put in back in her machine and see what happens.
Thanks for the input,
Peter Moss
>
>Yeah, I think my friend's PC can do this.
Just remember that it may look like it is formatting the drive but is
is not. Some PC system BIOSs have a format utility it is for ST412
interface drives (MFM/RLL) and not for IDE drives. Seagates sgatfmt
program will not format any Seagate drive that has "voice coil" head
actuator and/or ZBR. I am not sure what it does with old stepper
drives.
>drive. Bad sectors left & right. It's an old 100MB clunker. Track 0
>finally went bad and she couldn't boot anymore. I've tried every recovery
>
No 100 MB IDE drives that I know of can be formatted by the user. It
is a factory procedure only. YMMV. Most will just write a pattern to
the data area. In the old days you could fix this if there was a good
sector remaining on track 0 head 0 by reordering the sectors and
numbering a good sector sector 1. A low level format is the only way
of doing this which is not available for IDE drives.
>I only would be cool to try to low-level it, though, since I've
>always been told you aren't supposed to do that. :-)
Some IDE drives can be damaged by low level formatting them. By
damaged I mean made useless for the task intended :-) No manufacture
that I know of has issued software to fix this situation if it occurs.
I would love to hear that they have taken a responsible attitude to
this problem and opologise if any manufacture has.
John Wehman
To add to this: the concept of "low-level format" is a hold-over from the earlier days of controller cards
controlling dumb drives (ESDI/MFM/RLL). There existed a need for the controller to sync up the sector skew,
sector ordering, and bad sector allocating whenever a drive was matched up with a new controller. This is
because the drive was dumb; no intelligence on board to determine these things.
With the advent of on-board controllers (ATA), this need for "low-level" formating went by the wayside. There
are several programs that will perform what they claim as "Low-level" formats. But, being that the command
set of ATA is very strict, and that there are no "low-level" commands per se, the only thing these programs
can do is invoke the "Format track" command (0x50), which varies in its implementation, but mainly writes a
simple data pattern to the data portions of the sector. There are some caveats to this; older ATA drives
sometimes could respond to variances in the 0x50 command by re-ordering the sectors (interleave) and resetting
and setting sector flag-bits. Today's drives however, do not perform any of these subtle maneuvers. Most
will simply write "00h" or "ECh" to the sector.
So, one could individually write each track of the drive by using debug and
o 1f6 a0
o 1f4 00
o 1f5 00
o 1f3 01
o 1f7 50
This would "Format track" the first data track (head 0, cylinder 0), and one could devise a program to
complete the rest of the drive. But, this is pretty much useless, unless something devastating happened to
the structure files (FAT, MBR, Partition records, etc) and these needed to be re-set to zero or something.
Regards,
>Peter
>--
>
>Peter Moss
>
>E-mail: pm...@yoda.alt.za
--
--------------------------------------------------------------------------
John Wehman -The opinions I express are solely
jwe...@picosof.com my own and in no way reflect those
john_...@notes.seagate.com of my employer's.
408-439-2123
--------------------------------------------------------------------------