Help with BDOS ERR [sysadminforum]

11-20-2003, 11:27 AM

Some help with the following prob would be much appreciated. - While trying
to format a CP/M disk (which I haven't done for years) I got the message
BDOS ERR ON A: BAD SECTOR.
I then pressed Return and I have now found that I shouldn't have done that
as CP/M will ignore the error and damage the format integrity of the current
disk.
I have a number of files on the disk which I can list and read any ASCII
data but they will not run.
Is it possible to recover the files ? Can anyone please help ?

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003

11-20-2003, 02:13 PM

Why were you trying to format a disk that had files on it that you
wanted in the first place?

A floppy disk format is destructive; there is no recovery reasonably
possible. This is true with PCs as well as with CP/M.

Alan Paton wrote:

    > Some help with the following prob would be much appreciated. - While trying
    > to format a CP/M disk (which I haven't done for years) I got the message
    > BDOS ERR ON A: BAD SECTOR.
    > I then pressed Return and I have now found that I shouldn't have done that
    > as CP/M will ignore the error and damage the format integrity of the current
    > disk.
    > I have a number of files on the disk which I can list and read any ASCII
    > data but they will not run.
    > Is it possible to recover the files ? Can anyone please help ?
    >
    >
    >
    > ---
    > Outgoing mail is certified Virus Free.
    > Checked by AVG anti-virus system (http://www.grisoft.com).
    > Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003
    >
    >

11-20-2003, 03:44 PM

"Alan Paton" <alanpaton@ntlworld.com> wrote in message
news:3A1vb.3543$4Y6.673@newsfep4-winn.server.ntli.net...
    > Some help with the following prob would be much appreciated. - While
trying
    > to format a CP/M disk (which I haven't done for years) I got the message
    > BDOS ERR ON A: BAD SECTOR.
    > I then pressed Return and I have now found that I shouldn't have done that
    > as CP/M will ignore the error and damage the format integrity of the
current
    > disk.
    > I have a number of files on the disk which I can list and read any ASCII
    > data but they will not run.
    > Is it possible to recover the files ? Can anyone please help ?

If you haven't used the drives in a while you could have problems with them.

One common problem is that old disks sometimes flake off some of the oxide
and stick to the drive heads. If this happens the oxide stuck on the head
will destroy every disk you stick into the drive until you clean the heads
(with alcohol). Look at the disk, if the oxide looks scratched stop and
clean the drive.

11-20-2003, 05:22 PM

Hi Barry
Sorry I didn't explain - The computer has two floppy's no hard drive and I
was using FORMAT.COM on the A drive to format a disk in the B drive.
The disk in the A drive has been changed in some way by the BDOS ERR

"Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
news:3FBCCBFA.4070907@neo.rr.com...
    > Why were you trying to format a disk that had files on it that you
    > wanted in the first place?
    > A floppy disk format is destructive; there is no recovery reasonably
    > possible. This is true with PCs as well as with CP/M.
    > Alan Paton wrote:
    > > Some help with the following prob would be much appreciated. - While
trying
    > > to format a CP/M disk (which I haven't done for years) I got the message
    > > BDOS ERR ON A: BAD SECTOR.
    > > I then pressed Return and I have now found that I shouldn't have done
that
    > > as CP/M will ignore the error and damage the format integrity of the
current
    > > disk.
    > > I have a number of files on the disk which I can list and read any ASCII
    > > data but they will not run.
    > > Is it possible to recover the files ? Can anyone please help ?
    > >
    > >
    > >
    > > ---
    > > Outgoing mail is certified Virus Free.
    > > Checked by AVG anti-virus system (http://www.grisoft.com).
    > > Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003
    > >
    > >

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003

11-20-2003, 08:32 PM

After you ignored the error and continued, what happened?

Alan Paton wrote:
    > Hi Barry
    > Sorry I didn't explain - The computer has two floppy's no hard drive and I
    > was using FORMAT.COM on the A drive to format a disk in the B drive.
    > The disk in the A drive has been changed in some way by the BDOS ERR
    >
    > "Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
    > news:3FBCCBFA.4070907@neo.rr.com...
    >
    >>Why were you trying to format a disk that had files on it that you
    >>wanted in the first place?
    >>A floppy disk format is destructive; there is no recovery reasonably
    >>possible. This is true with PCs as well as with CP/M.
    >>Alan Paton wrote:
    >>>Some help with the following prob would be much appreciated. - While
    >
    > trying
    >
    >>>to format a CP/M disk (which I haven't done for years) I got the message
    >>>BDOS ERR ON A: BAD SECTOR.
    >>>I then pressed Return and I have now found that I shouldn't have done
    >
    > that
    >
    >>>as CP/M will ignore the error and damage the format integrity of the
    >
    > current
    >
    >>>disk.
    >>>I have a number of files on the disk which I can list and read any ASCII
    >>>data but they will not run.
    >>>Is it possible to recover the files ? Can anyone please help ?
    >>>---
    >>>Outgoing mail is certified Virus Free.
    >>>Checked by AVG anti-virus system (http://www.grisoft.com).
    >>>Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003
    >
    >
    > ---
    > Outgoing mail is certified Virus Free.
    > Checked by AVG anti-virus system (http://www.grisoft.com).
    > Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003
    >
    >

11-21-2003, 08:40 AM

Hi I have some more info
The disk in Drive B formatted OK - then when I tried to use it after moving
some files on to it I got the BDOS ERR. I also got the error when I tried to
use the other disk.
Other disks and files function OK it is just the two disks involved at the
time which wont work.

I have now found that I had booted the computer using a disk with cp/m 2.2
but the disk with the FORMAT.COM on it was a cp/m plus disk. I think that
somehow by mixing the two systems the disk in the A drive at the time got
corrupted - or at least the system tracks are since I can read the data
files OK. I would prefer to use cp/m 2.2 as the rest of the disks I have
are using this system.

"Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
news:3FBD24C7.4040406@neo.rr.com...
    > After you ignored the error and continued, what happened?
    > Alan Paton wrote:
    > > Hi Barry
    > > Sorry I didn't explain - The computer has two floppy's no hard drive and
I
    > > was using FORMAT.COM on the A drive to format a disk in the B drive.
    > > The disk in the A drive has been changed in some way by the BDOS ERR
    > >

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003

11-21-2003, 08:46 PM

"Alan Paton" <alanpaton@ntlworld.com> wrote in message
news:Vdkvb.568$qn4.4558@newsfep4-glfd.server.ntli.net...
    > Hi I have some more info
    > The disk in Drive B formatted OK - then when I tried to use it after
moving
    > some files on to it I got the BDOS ERR. I also got the error when I tried
to
    > use the other disk.
    > Other disks and files function OK it is just the two disks involved at the
    > time which wont work.
    > I have now found that I had booted the computer using a disk with cp/m 2.2
    > but the disk with the FORMAT.COM on it was a cp/m plus disk. I think that
    > somehow by mixing the two systems the disk in the A drive at the time got
    > corrupted - or at least the system tracks are since I can read the data
    > files OK. I would prefer to use cp/m 2.2 as the rest of the disks I have
    > are using this system.

Generally speaking the "format" program (different systems sometimes had
different names) was hardware specific. I never saw one that cared what
version of CP/M it was running on.

Common problems with disk drives are: alignment, dirt, bad diskettes, head
pad for single-sided drives. There is a huge list of less common problems
including but not limited to track 0 adjustment, bad heads, electronic
failure, etc.

Drive alignment is a real problem with poor alignment it is common for you
to be able to format a disk and then read & write with no problems until you
move the disk to a different drive. The alignment is where the drive head
is placed exactly in line with one particular track (as I remember it is
track 38 on an 8" drive). Once that is done the drive should be able to
read or write any "standard" disk. It only takes a couple of minutes for a
tech to do it, but finding someone that can do it now is very difficult.

Maybe Herb Johnson can put his two cents worth here, you should go to his
site and read up on disk drives.

    > "Barry Watzman" <WatzmanNOSPAM@neo.rr.com> wrote in message
    > news:3FBD24C7.4040406@neo.rr.com...
    > > After you ignored the error and continued, what happened?
    > >
    > >
    > > Alan Paton wrote:
    > > > Hi Barry
    > > > Sorry I didn't explain - The computer has two floppy's no hard drive
and
    > I
    > > > was using FORMAT.COM on the A drive to format a disk in the B drive.
    > > > The disk in the A drive has been changed in some way by the BDOS ERR
    > > >
    > ---
    > Outgoing mail is certified Virus Free.
    > Checked by AVG anti-virus system (http://www.grisoft.com).
    > Version: 6.0.524 / Virus Database: 321 - Release Date: 06/10/2003