[ILUG] Making An Image Of A Floppy Disk Again

[Conor Daly]

On Fri, Dec 22, 2000 at 01:31:19AM -0800 or so it is rumoured hereabouts, 
kosullivan_xlib Last Name thought:
> I am trying to copy a JAWS (Job Access With Speach) for Windows Key Disk (1.44 mb)
> 
> I have been trying to us the dd command to create an image of a floppy disk the problem is that the disk that I'm trying to make an image of has bad sectors on it (or what appear to be bad sectors).  I've been using 
> 
> dd if=/dev/fd0 of=image.jaws conv=noerror
> 
> This gets all the data but the disk is copy protected and when writing the image.jaws file to a new disk the bad sectors cause the image not to be correct, which means that the copy of the key disk doesn't work. 
> The original disk doesn't seem to have bad sectors when it is being accessed by the jaws software.  I've even tried using a raw read raw write program for windows to copy the disk, that doesn't work either.
> 
> The output from the dd command for the jaws key disk is as follows.
> 
> dd if=/dev/fd0 of=image.jaws conv=noerror
> 2870+0 reads in
> 2870+0 reads out
> I/O Error
> 2872+0 reads in
> 2872+0 reads out
> I/O Error
> 
> This message is repeated a few times the "reads in" never get past 2872.
> 
> A normal floppy generates the following output
> 2880+0 reads in
> 2880+0 reads out
> 
> I have tried this on 2 machines so it can't be my floppy drive.
> 
> Can anyone tell me are these bad sectors or just a form of copy protection? 
> Can dd help me at all?
> 

Oh yes it can!  (Oh no it can't)  (OOPS, sorry, getting in panto mode
there!)

Assuming the resulting image is 2872 blocks in size, you can pad the gaps
with zeros.  Do something like:

dd if=/dev/fd0 of=part1.img bs=512 count=1870

That will get you the first bit of the floppy.  You _could_ try writing
that off to floppy and see if that works.  Otherwise continue with:

dd if=/dev/zero of=part1.img bs=512 count=1 seek=2870

That will skip the first 2870 blocks of output file.  then:

dd if=/dev/fd0 of=part1.img bs=512 count=1 skip=2871

will get the next good block.  Fill the rest of the image with zeros:

dd if=/dev/zero of=part1.img bs=512 count=8 seek=2872

That should get you a 1440k file with all the data in the right places.
If it's just bad sectors, the output should work on a floppy.  If not, I'm
stumped.
If you don't end up with the required 1440k file, you might need to do
each bit above to a seperate file (leaving out the "seek" keywords) and
then cat the files together to get the whole image.

HTH
-- 
Conor Daly <conor.daly at oceanfree.net>

Domestic Sysadmin :-)
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