Check the listing for details. TwinFamicom Expansion Port Switcher Mod. Condition: New. Listed at 33.90 USD. The TwinFamicom Expansion Port Switcher Mod will enable you to switch the role of the expansion controllers between internal and external on a TwinFamicom. The expansion ports on the Japanese Famicom consoles have a problem - some western games are incompatible with the controllers connected to this port, due to the fact that this expansion port did not exist on the NES, and therefore was ignored by some developers. Significant Titles Affected: Arkanoid II Battletoads Dragon's Lair Paperboy Pinball RoboCop 2/3 Star Force Super Mario Bros. USA Snake Rattle'n'Roll Terminator 1/2 Tetris (Tengen) Zelda II - The Adventure of Link This mod requires experience in console modding, both soldering and desoldering, and might not be friendly for everybody. Please keep this in your mind before attempting. Includes mod board and header pins. Two small wires (not included) are also required to complete the mod. This mod is the design of the AMAZING Jeff Chen (github.com/jeffqchen).