text:  // FamiTone2 audio library v1.15 by Shiru 04'17
  // vbcc6502 header, '2020 Lazycow
  
     // reset APU, initialize FamiTone
    // data: Pointer to music data
   // flags: 1 for NTSC mode
  //
  void ftInit(__reg("r0/r1") void* data, __reg("a") unsigned char flags);
  
   // init sound effects player, set pointer to data
  //
  void ftSfxInit(__reg("r0/r1") void* data);
  
    // play a music in ft format
   // song: Number of subsong
  //
  void ftMusicPlay(__reg("a") unsigned char song);
  
   // stop music
  //
  void ftMusicStop(void);
  
    // pause and unpause music
   // pause: 0 to play, !=0 to pause
  //
  void ftMusicPause(__reg("a") unsigned char pause);
  
     // play ft sound effect on channel 0..3
    //  sound: Number of the sound effect, 0..127
   // channel: FT_SFX_CH0, FT_SFX_CH1, FT_SFX_CH2 or FT_SFX_CH3
  //
  void ftSfxPlay(__reg("a") unsigned char sound, __reg("r0") unsigned char channel);
  	enum { FT_SFX_CH0=0, FT_SFX_CH1=15, FT_SFX_CH2=30, FT_SFX_CH3=45 };
  
    // play a DPCM sample
   // sample: Number of the sample, 1..63
  //
  void ftSamplePlay(__reg("a") unsigned char sample);
  