2年前，Fenner Investment對Sony、任天堂及Microsoft所生產的某些遊戲機，提出了US6,297,751號專利侵權訴訟。旋即在2個月後撤銷了對Sony的控告，但仍與任天堂及微軟持續纏訟。2009.3.16.美國地方法院判決，Microsoft與任天堂並未侵犯Fenner Investment的遊戲搖桿而結束了這起長達2年的案件。
Title:Low-voltage joystick port interface
The joystick port interface includes an integrated circuit receiving an analog joystick position measurement signal and outputting a digital pulse signal to a processor which signifies a joystick coordinate value. The integrated circuit includes a pulse generator and a bidirectional buffer circuit. The bidirectional buffer circuit receives the analog joystick position measurement signal and selectively discharges an RC network capacitor which provides this analog measurement. This implementation provides a joystick port which uses low-voltage CMOS VLSI structures which can interface a conventional high-voltage joystick with the processor.