Instructables user mattpbooth has updated the code and is hosting it on github:
Replaced a println with print (derp).
Remade all code from scratch.
Remade 'ible code section; Now includes a 'Processing COM port config for dummies'
Ladies and gentlemen, I proudly present 8bit pleasure.. yours for the grabbing! Whether you use GNU/Linux, Mac OS X, or Windows the USB NES controller is compatible.
Will this in any way alter the controller?
Nope, the controller will stay the same so you can still use it on a real NES
But I don't have an arduino ;_;
You can use the parallel port: http://hellalame.com/nes/nes_controllers.html
Buy an arduino: http://hellalame.com/nes/nes_controllers.html
Or a retrozone NES kit: http://hellalame.com/nes/nes_controllers.html
Step 1: Ingredients for some awesome controller soup
A NES controller
A USB cable type B
Something you can use as a Casing
and some wire..
Optional: NES port http://www.parallax.com/Store/Components/Other/tabid/157/CategoryID/32/List/0/SortField/0/Level/a/ProductID/522/Default.aspx
Arduino software http://arduino.cc/
Step 2: How to connect the arduino to the nes controller
You could also use the controller port from a NES (a broken one, don't waste a working one).
You want something vaguely similar to the last picture.