Int 2F Fn 150B  - Cd-rom V2.00+ - Drive Check                              [d]

   AX = 150Bh
   CX = drive number (0=A:)

Return: BX = ADADh if MSCDEX.EXE installed
       AX = 0000h if drive not supported
       nonzero if supported

See Also: AX=150Dh