How Screwed up can the formatting of an IDE disk get ?

  • Thread starter Thread starter Al Dykes
  • Start date Start date
A

Al Dykes

I've been asked to fix a machine that has a WD200 (20GB) disk
in it (I looked) but the CMOS detect thinks it's a 1GB disk.

When I discovered this by trying to do a low level format, expecting
to see 20GB of space, I looked at the CMOS and found that instead of
Autodetect the PC had manual settings for Cyl/Head/Sector figures that
worked out to be 1GB. FORMAT has been run on top of this.

I set CMOS to autodetect and it still find the 1GB settings
that the disk knows.

I'm about to look on the WD web site and see if there is a
utility to resort this disk to factory settings.

Is my guess that the manual settings, combined with a format, have
screwed up the disk, at least until I can run the WD utility, valid ?

Will the WD utility fix it ?
 
I've been asked to fix a machine that has a WD200 (20GB) disk
in it (I looked) but the CMOS detect thinks it's a 1GB disk.

When I discovered this by trying to do a low level format, expecting
to see 20GB of space, I looked at the CMOS and found that instead of
Autodetect the PC had manual settings for Cyl/Head/Sector figures that
worked out to be 1GB. FORMAT has been run on top of this.

I set CMOS to autodetect and it still find the 1GB settings
that the disk knows.

I'm about to look on the WD web site and see if there is a
utility to resort this disk to factory settings.

Is my guess that the manual settings, combined with a format, have
screwed up the disk, at least until I can run the WD utility, valid ?

Will the WD utility fix it ?
Click to expand...

To provide additional information, you can download Findpart for DOS
at

http://www.partitionsupport.com/utilities.htm

do:

findpart ide fp.txt

and

findpart tables fp-a.txt

and insert (not attach) the output files here.
 
Al said:
I've been asked to fix a machine that has a WD200 (20GB) disk
in it (I looked) but the CMOS detect thinks it's a 1GB disk.

When I discovered this by trying to do a low level format, expecting
to see 20GB of space, I looked at the CMOS and found that instead of
Autodetect the PC had manual settings for Cyl/Head/Sector figures that
worked out to be 1GB. FORMAT has been run on top of this.

I set CMOS to autodetect and it still find the 1GB settings
that the disk knows.

I'm about to look on the WD web site and see if there is a
utility to resort this disk to factory settings.

Is my guess that the manual settings, combined with a format, have
screwed up the disk, at least until I can run the WD utility, valid ?

Will the WD utility fix it ?
Click to expand...

First, if that HD has useful data, back it up. Second, verify the
backup. Third, test the backup.

Whatever you do to convert that 1GB HD back to a 20GB HD will almost
certainly blow away the directory structures, making the data *very*
hard to access.
 
Not having seen this particular anomaly, I'm kinda shooting at the hip
here, but what is the motherboard of the machine? Is it capable of
seeing drives that large? Seems to be only a few years ago that 32gb
was the max on some boards... Must have had a lower limit before that
too ;)

Might want to update the bios on the motherboard to be sure that's not
corrupt, too..

Have you tried putting that drive in another machine to see what it's
detected as there?
 
Not having seen this particular anomaly, I'm kinda shooting at the hip
here, but what is the motherboard of the machine? Is it capable of
seeing drives that large? Seems to be only a few years ago that 32gb
was the max on some boards... Must have had a lower limit before that
too ;)

Might want to update the bios on the motherboard to be sure that's not
corrupt, too..

Have you tried putting that drive in another machine to see what it's
detected as there?
Click to expand...

Good suggestions;

The machine is modern enough to boot from CD and my memory is that
the jump was from 512MB to 2GB. 1GB is an odd number.
 
Ok, Al... if it can boot from CD, I'd say it *should* be modern enough
to see a 20gb drive.... After all... nowadays that's barely enough for
a batch file, if it's written in Visual Bloat... ;)

I still think reflashing the bios can't hurt.... and search the WD
again for that lowlevel util.... and if there is ANY way possible...
put the drive in another known working machine to run the util...
(without any other drives hooked up).... no sense in taking a chance
of trashing another drive when you "fix" this one ;)
 
If there is a valid MBR, BIOS will get disk parameters from it. Since your
MBR describes the disk as 1 GB, this is what BIOS would report. Run WD test
utility in write test for a while, to allow it to overwrite the beginning of
the disk, then after reboot the BIOS is supposed to detect the disk size
properly.
 
If there is a valid MBR, BIOS will get disk parameters from it. Since your
MBR describes the disk as 1 GB, this is what BIOS would report. Run WD test
utility in write test for a while, to allow it to overwrite the beginning of
the disk, then after reboot the BIOS is supposed to detect the disk size
properly.
Click to expand...

Thanks, good pointer.
 
I've been asked to fix a machine that has a WD200 (20GB) disk
in it (I looked) but the CMOS detect thinks it's a 1GB disk.
Click to expand...
When I discovered this by trying to do a low level format, expecting
to see 20GB of space, I looked at the CMOS and found that instead
of Autodetect the PC had manual settings for Cyl/Head/Sector figures
that worked out to be 1GB. FORMAT has been run on top of this.
Click to expand...
I set CMOS to autodetect
Click to expand...

You mean you used the AUTO drive type setting
or you used the autodetect menu entry in the bios ?
and it still find the 1GB settings that the disk knows.
Click to expand...

Thats normal, AUTO does use the geometry details in the MBR.

Run clearhdd on the drive to wipe the MBR completely and an
AUTO drive type and the drive should show up as the full size.

If it doesnt, the drive has been short stroked to 1GB by some
incompetant moron. Just reset that using Hitachi's Feature Tool.
I'm about to look on the WD web site and see if
there is a utility to resort this disk to factory settings.
Click to expand...

Already answered separately.
Is my guess that the manual settings, combined
with a format, have screwed up the disk,
Click to expand...

Just put useless values in the MBR most likely.
at least until I can run the WD utility, valid ?
Click to expand...

You likely just need to wipe the MBR.
Will the WD utility fix it ?
Click to expand...

Nope.
 
Randy Miller said:
Ok, Al... if it can boot from CD, I'd say it *should* be modern enough
to see a 20gb drive....
Click to expand...

Nope, El Torito bootspec (ca. '95) came before Int13 extensions (ca. '96/'97).
 
Alexander Grigoriev said:
If there is a valid MBR, BIOS will get disk parameters from it.
Click to expand...

Not for physical size detection.
Physical size is read from the drives configuration sector (auto) or from
the P-CHS values from CMOS (user).
Since your MBR describes the disk as 1 GB, this is what BIOS would report.
Click to expand...

Not the bios utility.
Some OS Utilities however may use the bios logical CHS for calculat-
ing physical drive size when other bios calls should be used for that.
 
Folkert Rienstra said:
Nope, El Torito bootspec (ca. '95) came before Int13 extensions (ca. '96/'97).
Click to expand...
T13's EDD 1 is dated July 1999. However, Phoenix invented the Int13 extentions
long before that.

From http://www.phoenix.com/resources/specs-edd11.pdf, version 1.0 is dated
Jan 1994 and version 1.1 is dated Jan 1995.

My first computer was a 486 with Phoenix BIOS dated 1994, and it had Int13
extentions. I had a 540MB disk and I could disable CHS translation. With DOS
7.0 or prior, fdisk reported 512MB, but DOS 7.1 (Win 95B) fdisk reported
540MB.
 
T13's EDD 1 is dated July 1999. However, Phoenix invented the Int13 extentions
long before that.

From http://www.phoenix.com/resources/specs-edd11.pdf, version 1.0 is dated
Jan 1994 and version 1.1 is dated Jan 1995.

My first computer was a 486 with Phoenix BIOS dated 1994, and it had Int13
extentions. I had a 540MB disk and I could disable CHS translation. With DOS
7.0 or prior, fdisk reported 512MB, but DOS 7.1 (Win 95B) fdisk reported
540MB.
Click to expand...


Thanks to the early responses that told me to overwrite the MBR. It
fixed my disk and learned something.
 
Eric Gisin said:
T13's EDD 1 is dated July 1999.
Click to expand...

i.e. D1386, BIOS Enhanced Disk Drive Services (EDD)

Yup, that's the one I looked at first and then I found D1226, Enhanced
BIOS Services For Disk Drives, October 23, 1996 Initial Release
that already mentioned EDD. Guess that one isn't the one either then.
 
low level formatting should only be done at the factory. WD cant help
you any more now... toss it.
 
DaveinOlyWa said:
low level formatting should only be done at the factory. WD cant help
you any more now... toss it.
Click to expand...

You can't be helped either. Consider yourself tossed.
 
i didnt call it anything...

the original poster did...

maybe you should learn to read
 
DaveinOlyWa said:
i didnt call it anything...

the original poster did...

maybe you should learn to read
Click to expand...

Clueless!

"Thanks to the early responses that told me to overwrite the MBR.
It fixed my disk and learned something".

Certainly *YOU* should learn to read. (And then learn to post).
 
Al Dykes said:
Thanks to the early responses that told me to overwrite the MBR.
It fixed my disk and I learned something.
Click to expand...

Btw, some bioses *do* /shortstroke/ the drive to the capacity set by CMOS
in certain cases which however can be reset by a new SET MAX ADDRESS.
 
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