detect_digi_driver - Detects whether the specified digital sound device
is available. Allegro game programming library.
#include <allegro.h>
int detect_digi_driver(int driver_id);
Detects whether the specified digital sound device is available. This
function must be called _before_ install_sound().
Returns the maximum number of voices that the driver can provide, or
zero if the hardware is not present.
install_sound(3alleg), reserve_voices(3alleg)