DIGI_AUTODETECT      - let Allegro pick a digital sound driver
      DIGI_NONE            - no digital sound
      DIGI_DIRECTX(n)      - use DirectSound device #n (zero-based)
			     with direct mixing
      DIGI_DIRECTAMX(n)    - use DirectSound device #n (zero-based)
			     with Allegro mixing
      DIGI_WAVOUTID(n)     - high (n=0) or low (n=1) quality WaveOut
			     device