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

   AX = 4F13h
   BX = 0000h

Return: AL = 4Fh if function supported
       AH = status
       00h successful
           BX = version (0010h for 1.00 -- note nonstandard value!)
       01h failed

See Also: AX=4F13h/BX=0001h,AX=4F13h/BX=0005h