Re: [ARSCLIST] CD writing speed

[Mike Richter <mrichter@xxxxxxx>]

steven c wrote:

> Is there a way to copy a damaged file "as is" to your HD? If the contents
> are a program, of course, it will be useless if damaged...but for text
> files and some types of program files, any data not containing the faulty
> bits will be useful. I've often tried to get useful data from bad floppies
> by running SCANDISK...it provides the original data minus the faulty
> sector(s) and saves the damaged data using generic filenames (which may
> or may not contain anything useful).
>
> Can this be done with "unreadable" data CD_R's?
>
> Steven C. Barr

As always I like to be definite. The answer is 'yes and no'.

The file seldom can be copied because such errors usually generate CRC 
errors and a file with an invalid CRC cannot be written by the OS. 
However, the values in the sectors of which the file is composed can be 
written to the HD. Tools for that purpose are available from Ininfadyne; 
I've used them and they work.

The problem is not solved when the sectors are copied; they need to be 
linked correctly before even the faulty bytes can be located and 
corrected. Note, too, that the linkages are subject to the same sort of 
error as the data themselves. Tracing and reconstructing such material 
is a classic forensic problem and I believe there are tools for that as 
well. I have not investigated or used any such tools.

Mike
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mrichter@xxxxxxx
http://www.mrichter.com/