// Returns `true` if the MDRV2 driver is resident. bool16 mdrv2_resident(void); // Returns `true` if an FM sound source is installed. int mdrv2_check_board(void); void mdrv2_bgm_load(const char *fn); void mdrv2_se_load(const char *fn); // Plays back the BGM file that was previously loaded via mdrv2_bgm_load(). void mdrv2_bgm_play(void); void mdrv2_bgm_stop(void); void mdrv2_bgm_fade_out_nonblock(void); void mdrv2_se_play(int se);