[Bug-ddrescue] Using ddrescue on some really bad floppies

[Ian Oliver]

First of all, many thanks for ddrescue. I've used it on hard disk 
belonging to many friends, relatives, and colleagues, and it's always 
done a brilliant job of getting back their data, 100% of it in the 
majority of cases.

I'm now trying to use it on some 22 year old 5.25" floppies, and I'm 
hitting the limit of what ddrescue can do. Many sets of floppies read 
100% after (often huge) numbers of retries, but I have one last set of 
six disks that are pretty basket case. One example here still has 64 
bad sectors and didn't get even one more sector off in a 12 hour run.

I'm about to roll up my sleeves and write some Python to parse the 
ddrescue log and then try to use fdrawcmd to pull off the sectors while 
ignoring CRC errors. I'm not desperately hopeful, but assuming the 
controller can find the headers, perhaps I can pull the damaged body 
off several times then try and use semi-psychic techniques to patch up 
some data.

Has anyone ever done anything like this?

I note that BSD has a utility called fdread that claims to read disks 
and ignore CRC errors.

http://nixdoc.net/man-pages/FreeBSD/fdread.1.html

Is there anything like this for Linux?

Ian