Need good disk dump utility

[Dwight K. Elvey]

>From: "Scott Stevens" <chenmel at earthlink.net>
>
>On Sat, 23 Apr 2005 16:11:11 -0700 (PDT)
>Vintage Computer Festival <vcf at siconic.com> wrote:
>
>> 
>> I'm currently using Anadisk to dump disks into image files.  The
>> problem is, Anadisk, like 22disk, is retarded.  If it hits an error it
>> skips the sector but does not put a blank sector in the image file. 
>> You have the option of placing a sector header before each sector, but
>> for manipulating disk images, this is a piss poor way to mark missing
>> sectors.  Anadisk also has the annoying habit of ignoring the start
>> and finish cylinders and merrily proceeds to read the entire disk,
>> relegating the need to ask you what cylinders you want dumped
>> superfluous.
>> 
>> Is there anything in Linux that will dump a disk image and put blank
>> space where bad sectors are?  It's not certain if dd does this.
>> 
>> I'm sick of the crap programming of others.  Must I write *EVERYTHING*
>> myself?
>> 
>
>Well, the cool thing about the free Unices (and Linux) is that you can
>dig into the source code for dd and find out.  And if it doesn't put
>blank space where errors occur, you can modify it to do so.  Perhaps
>with a command-line switch option, if one doesn't already exist.
>
>> I'm sick of the crap programming of others.  Must I write *EVERYTHING*
>> myself?
>
>Naw, just the bit that will scratch your particular itch.  And if you
>make changes to dd and submit your changes back, nobody else will have
>to rewrite it either.
>

Hi
 Not only should it pad the empty space but it should also
write the buffer values that may have been read if it was
just a crc error on the data portion. These are often just
missing one bit and can be recovered with a little bit of
work.
Dwight