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