This pertains to the no-chip playstation disc topic and the EFM/AWS topic, but is a separate question, it is a problem I have come across the past month with copying audio CDs with CloneCD and other DAO RAW 96 compatible programs.
I have a LiteOn LTR-24102B drive and I have burned many a disc and then tested the track CRC values with EAC. The CDs I have been copying are regular audio CDs with no copy protection that I know of, unless they contain some "bad Subchannel data" Audio CD" copy protection" That I am not aware of. (ClonyXXL tells me they are regular audio CDs.)
"Copy protection" is Dr. Evil style, because, in essense, this is not copy protection really at all, because it does not keep anyone from ripping the cd, it only affects creating a 1:1 copy, which I have yet been able to do. I have discerned that it has something to do with the subchannel data or the Pregap data more specifically. My drive will read this information perfectly, because I have used Daemon Tools to verify the CRCs with CloneCD images along with EAC. The image works perfectly and retains the same CRCs as the original, including the same progap information.
The problem comes when I burn a DAO RAW 96 copy with CloneCD. The copy may contain some tracks that have the same CRC, but 3 or 4 may not. This has occurred with more than one CD. I have set the program to "Don't Repair Subchannel Data" and am writing at the lowest speed possible, and I still produce the same cd time after time with slightly different PreGaps, and of course different CRC values for the tracks.
I assume this has something to do with not being able to write the exact PreGap information that the image contains, as what was said in the PSX topic, we can read the data, but dont have software to write it yet. I figure this has something to do with writers writing RAW/2352 and not the "full" 2448 or something of this sort for which CDs truly contain... but I am not certain.
What is the issue here keeping me from making 1:1 copies of audio cds, and is this the same issue (and roadblock) that is effecting PSX copies, etc?
Update: I forgot to mention that I have tested one CD-Text disc, and many that are not...both give me some different crcs, so I assume this does not just affect cds with extra subchannel data added on purpose (the CD-Text)