Howdy! I'd like to ask a question dealing with playing burned (backups) games on the PS2. I'm not 100% sure as to where to go to find the answer to this question, and am not even sure what keywords to use in the search here to possibly find the answer, so I'm going to post my question. Any information (on the answer or where to find the answer) would be greatly appreciated. I'm confused as to how the PS2 can know whether or not a disk that you insert is either an original or a copy. For sake of example, I'm going to use one of the games I bought at a Gamestop recently: Digital Devil Saga 2. Let's say I burn a back-up copy to play from. When looking at the bottom side of the disk, both disks looks almost exactly the same to what I can see. If I put the original in, it plays. Theoretically, if I put the backup in, I'd get an error saying it's not a valid disk. I'm curious how the PS2 knows that the back-up is a copy and not the original when they look almost exactly identical? My thanks in advance for any clarification I can get! C. J.