Int 6D Fn BDFF  U - Matrox Multiple Monitor Support V1.0 - Unhook Interru  [V]

   AX = BDFFh

Return: AX = 00BDh if supported

Note:  this function revectors INT 6D without checking that it points at the
     TSR, and does not release the memory occupied by the TSR

See Also: AX=BD60h,AX=BD61h,AX=BD6Fh