Int 2F Fn BC00  - Mediavision Mvsound.sys - Installation Check             [s]

   AX = BC00h
   BX = 3F3Fh ('??')
   CX = 0000h
   DX = 0000h

Return: if installed, BX XOR CX XOR DX = 4D56h ('MV')
Program: MVSOUND.SYS is a driver for the MediaVision ProAudio Spectrum family
     of sound boards; its primary programmer was Bryan Crane

See Also: AX=BC01h"MVSOUND",AX=BC02h,AX=BC03h,AX=BC04h,AX=BC06h"MVSOUND"