Re: [Libcdio-devel] Using major/minor device numbers to determine SCSI or ATAPI

[R. Bernstein]

Steven M. Schultz writes:
...
 >      Ah, I don't think that's necessarily the case.  But without otherwise
 >      identical drives with the difference interface electronics (at one
 >      time there were numerous SCSI CDROM drives available - haven't seen
 >      one in a long time).
 >      
 >      In any case I am not sure it's the transport needs to be checked, but
 >      the capabilities of the drive.  Isn't there a bit/byte in the
 >      drive that can be fetched that says what order the audio data is
 >      presented in?  The MMC specs are online (had a copy - hundreds of
 >      pages - printed out at one time but tossed it a while back).

I don't recall seeing anything on drive endianness or order of bytes
from audio data. Also, I guess cdparanoia (and libcdio) wants to
support a drive whether or not it is MMC capable. One might think that
OS's now makes all drives look MMC capable, but I don't have enough
experience to know if that's really true.

 >      Right - and on BSDI /dev/rsr0c is 18 (as you can check on 'awds1' ;)).
 >      That happens to be an ATAPI drive but a long time ago when it was
 >      a SCSI CD burner it was still 18 for a major number.

Okay. That's why I'm asking. I don't have much experience on most of the OSs.

 >      A more portable way would be to query the drive - I can't escape the
 >      feeling there's a MMC{2,3} 'mode sense' or 'inquiry' command that
 >      will get the info from the drive.

Again, if you or anyone else can find something about drive endianness
in any of the SCSI/MMC specs I'd appreciate learning. It may even be
that if it's MMC it's defined to be little endian. That's what most of
the drives I've enountered have been so far and cdparanoia thinks all
ATAPI drives are little endian.