Int 66 Fn 0698  - Digpak - Set Play Mode                                   [s]

   AX = 0698h
   DX = playback mode
       0000h 8-bit PCM
       0001h 8-bit stereo PCM
       0002h 16-bit PCM
       0003h 16-bit stereo PCM

Return: AX = status
       0000h command ignored
       0001h mode set