NAME
        GPD_SETCTYPE -- Set the current game port controller type

   FUNCTION
        This command sets the type of device at the game port, so that
        the signals at the port may be properly interpreted.  The port
        can also be turned off, so that no reports are generated.

        This command always executes immediately.

   IO REQUEST
        io_Message      mn_ReplyPort set if quick I/O is not possible
        io_Device       preset by the call to opendevice
        io_Unit         preset by the call to opendevice
        io_Command      GPD_SETCTYPE
        io_Flags        IOB_QUICK set if quick I/O is possible
        io_Length       1
        io_Data         the address of the byte variable describing
                        the controller type, as per the equates in
                        the gameport include file