Int 10 Fn 4F13  - Vesa Vbe/ai (audio Interface) - Locate Device            [s]

   AX = 4F13h
   BX = 0001h
   CX = 0000h ???
   DX = type of device
       0001h Wave device
       0002h MIDI device
       0003h Volume device

Return: AL = 4Fh if function supported
   AH = status
       00h successful
       CX = handle [returned 1 for DX=1 and 3, and 2 for DX=2]
       01h failed

See Also: AX=4F13h/BX=0000h,AX=4F13h/BX=0002h