[RyanN]

No, this is not legal if you are asking if you can have 2 Operator Interfaces. Yes if you mean you want more than one joystick, just plug them into the other ports on the O.I. Why would you want 2 Operator Interfaces anyway? You have I believe like 52 ports to play with (excluding the power ports on the 15 pin connectors)

You can have anything you want connected to your O.I.'s game ports as long as they get all the power they need through those ports and nothing else, except for the game port to usb adapters.