proc music_setting
  mov si, 0
  mov al, 0b6h
  out command_reg, al
  ret
endp


proc speaker_activation
  in al, port_b
  or al, 00000011b
  out port_b, al
  ret
endp


proc speaker_disactivation
  in al, port_b
  and al, 0fch
  out 61h, al
  ret
endp