Usage:

PlayCDDA DEVICE=DRIVE/K,TRACK/N

List tracks on disc in drive "CD0:":
PlayCDDA

Play track #1 from disc in drive "CD0:":
PlayCDDA 1

List tracks on disc in drive "CD1:":
PlayCDDA drive CD1:

Play track #2 from disc in drive "CD1:":
PlayCDDA drive CD1: 2

Changes:

1.4 (27-Oct-2009)
 - Removed the io_Unit check from DoSCSICmd because some device drivers set
   this field to NULL even they open successfully

1.3 (27-Oct-2009)
 - Fixed playback of the first track on an Audio CD
 - Tracks are now numbered starting with track #1 instead of #0
 
1.2 (19-Oct-2009)
 - PlayCDDA now obtains the device/unit information using dos.library
 - If no track number is specified PlayCDDA will list all data/audio tracks on
   the CD in question

1.1 (4-Aug-2009)
 - First released version