NAME
       CD_PLAYTRACK -- Play one or more tracks of CD audio.

   IO REQUEST
       io_Device       preset by the call to opendevice()
       io_Unit         preset by the call to opendevice()
       io_Command      CD_PLAYTRACK
       io_Data         NULL
       io_Length       number of tracks to play
       io_Offset       start playing at beginning of this track

   RESULTS
       io_Error        0 for success, or an error code as defined in
                       <devices/cd.h>
   FUNCTION
       This command causes the drive to play the specified audio track(s).
       The command will return when the audio has completed.

       io_Offset specifies the track number (starting from 1).

       io_Length specifies the number of tracks to play (0 is invalid).

   EXAMPLE

       ior->io_Command = CD_PLAYTRACK;    /* Play audio tracks     */
       ior->io_Offset  = STARTTRACK;      /* Start with this track */
       ior->io_Length  = 3;               /* Play three tracks     */
       DoIO(ior);

   NOTES

       PLAY commands are asynchronous with many other CD commands.
       Using a separate I/O request, other commands can be sent to the device
       that can change the behavior of the PLAY command.

   BUGS

   SEE ALSO
       cd_playmsf, cd_playlsn, cd_pause, cd_search, cd_attenuate