> I have to admit that I don't even know what UPC is. > OTOH this should be tested by a developer who is at least able to > detect if UPC features are even searched for by these games. > Both in a OAKCDROM and UDVD2 environment. Jack is absolutely right > to refuse to implement UPC just in case it might be required by some > games.
As Eric later responded, UPC and EAN are the same thing (and since you are from Germany I assume you know what EANs are). This goes back to the early days of audio CDs when the manufacturer would include the UPC/EAN code electronically on the CD. This would theoretically allow you to download the metadata for the audio CD (Artist, Title, Song List, Lyrics, Album Art, etc.). Each song also has a number code for it (called the ISRC), though those are not always embedded on the CD. All of this data is stored in sub-channnel data on the CD. In addition to the 2048 bytes of "regular" sector data, each sector also contains a small amount overhead/formatting information and sub-channel data. There are 8 sub-channels available (P, Q, R, ..., W) but on audio CDs only P & Q are defined in the standards. The Q sub-channel contains sector information (on audio CDs this is the Minute-Second-Fractional Second information), UPC code, and ISRC data. In the device driver standard for DOS, there are standard IOCTL requests you can issue to the CD player to obtain various kinds of sub-channel information. The fact that Jack (and apparently you) think they are unneeded is irrelevant. They are part of the standard and should be implemented. They are in fact useful for audio CDs, and it doesn't matter if some game CDs use them for copy protection or something else. The drivers need to implement the standard as fully as they can and not decide for the user what they don't want. As far as implementation, there are standard SCSI requests associated with obtaining the sub-channel information, and one specifically dedicated to obtaining the UPC/EAN code. This is not difficult to implement in the software, as long as the hardware (CD player) supports it. _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
