May I ask a few follow-up questions to what you said on the other question?
>> The extra bytes in a raw sector cannot always be read from a CD-ROM, it depends upon the CD-ROM drive.
Hmmm... Can all SCSI drives read raw sectors? Or does it simply depend on the manufactorer/model? Can all newer drives read raw sectors? Or are there new drives, than can't do that, either? How do those drives behave, do you know what error they return, if you try to use raw-read? (My drives all support raw read, so I don't know how other drives behave...)
>> Note also that on some drives you can read the 'scrambled' data, this means the data within the raw sector is shuffled around (with the exception of the header) to aid in error correction and detection.
Hmmm... I don't understand that part. Does that mean that on some drives a raw-read gives me the data in a different order than a normal read would do?
>> If however you are simulating a protected CD at device level then I don't think you need to worry about the contents of the error correction and detection (ECC and EDC) since I am not aware of any copy protection system that actually uses this extra data. All you need to worry about is returning the correct return status (can/can't read sector) which is what most of these protections use!
Hmmm... Yes. But I've planned something like this: I want to read all CDs in raw-read mode, if the drive supports that (because if I read a copy protected CD in normal mode it takes hours to do so). Then I can simulate raw-read mode later. But of course I have to simulate normal-read mode, too. So I need to be able to see from the raw-read data block, how a normal-read of the same block would behave. So I guess, I will at least have to calculate that CIRC sum to detect sectors that are not readable in normal mode, right?
>> You will probably realise that I know something about these protections by my alias!
Yep - that's right!! I saw you only as a questioner, not as an expert. Now I'm wiser... :-)
Another question: When searching for the Yellow Book I read about a Green Book and White Book and Orange Book and XXX Book and CDROM XA and Mixed Mode and whatever. Can computer drives read all those stuff? Can Windows use it? If yes: How does Windows read such CDs? In normal or raw mode? I mean, the audio data uses more than those 2048 Bytes, so audio must be read in raw-mode, or am I wrong?
If I use raw-read and simulate raw-read AND normal-read from that raw-read-harddisk-image, would that contain a perfect simulation of ALL those formats?
What about DVD? Does the Yellow Book apply there, too?
Thank you very much for your help!!
Regards, Madshi.
