Imaging Old Disks Advice Needed

[allison]

On 11/1/16 6:39 AM, Peter Cetinski wrote:
>> Out of curiosity, since I've never done this either but have heard most folks suggest it. How do you seal the newly made jacket? Is it not necessary or folks using scotch tape?
> Well, I made a number of these this weekend and I just left the end open.  The hub keeps the cookie in place.  Thanks to everyone for the input.
>
> So, I was able to image half of the disks without issue.  The others all had a few bad tracks.  On most of those I don't see any physical damage so I was wondering if there were any other techniques to possibly recover those tracks?  Baking the cookie?  Is there a good tool to merge tracks from multiple disks if I find another copy of the software that has the missing tracks?
Depending on the on disk format and the filesystem it can be very hard 
to do that as you have to know the relative position in the file.

What can you do for specific files is to first clean the heads, each and 
every time as old disks may leave abrasive crap behind
and that can kill good media.  The other is does the sections not 
readable actually contain data?  Some file systems do scatter/gather
so they can efficiently use the whole disk space (CP/M, DOS for PCs to 
name a few).

Then it requires digging into the hard/software to do low level reads 
without error checking or despite it.
For many that goes to a level well beyond trivial.

Allison