I'm going to be looking at for this. It's reported to :- "also provides detailed reporting of any errors detected." Haven't tried it yet - might get a chance tonight. (It's a "free for home use " licence). I did look at (http://www.jufsoft.com/badcopy/) but it requires $40 payment to be able to save the recovered data & didn't look as if it gave out too much info on errors rates detected. http://www.naltech.com/index.htm appears similarly restricted. (All these links are from ) The article below (http://www.itl.nist.gov/div895/gipwg/StabilityStudy.pdf ) appears to correlate jitter with error rate to a reasonable degree, so something that monitored the raw data from the CD & displayed the jitter level may be a useful indication of pending failure. Might not be too hard to implement if you can get access to the raw data stream. Maybe a suitable project for the SX contest! Richard P (http://www.naltech.com/index.htm). > 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. Thanks, Christian -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist