On Sun, 23 Jan 2005, csb wrote:

>> http://www.itl.nist.gov/div895/gipwg/StabilityStudy.pdf
>
> Quite interesting... Does anyone know a program (freeware maybe? 
> Whatever OS, as long as it's for a PC) that measures/quantifies/checks 
> CD quality? I noticed that some CDs I have take a few minutes to be 
> recognized by the computer... Other than that I have no way of 
> evaluating the quality of my discs.

The only two ways I know of are to quantify the read speed of the cd in 
a known drive (low speed = read errors and/or other degradation), and to 
periodically read back all data (image copy) to make sure it still 
works. In theory I think that the read speed is an indicator of the 
contrast factor on the cd.

I am no expert on this but it seems to me that the track 0 (TOC etc) 
area of a cd is it's Achilles heel. If that area goes bad the disk is 
becomes a coaster although I read that some methods to extract data even 
after such a failure exist. This also means that statistically the 
probability to be able to recover data written over many disks is 
inversely proportional to the amount (capacity used) written to each 
disk.

Peter
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