I ordered four of these a few days ago and they arrived today:

http://www.monoprice.com/products/pr...seq=1&format=2

They work great! This is the exact same connector used in the USA TurboDUO (and all Japanese PC-Engine related consoles), and at $1.47 each, you can't beat it. I even hooked two of the together and then to the gamepad and was able to play Air Zonk from the furthest end of the couch Awesome...