First of all, I would like to comment that I'm endebted to this page for almost everything I know about the NES controllor. (Which isn't much, they're very simple devices)

As a side note, many people have asked me why I chose the NES controllor as a input device for my EV's computer. Well, there are a number of reasons, but the most obvious ones are that they are incredibly cheap, and the layout is familiar to most people. Beyond that, I guess I thought originally they'd be easy to input because they were simple matrix controllors. As it turns out, they aren't simple matrix controllors, but this doesn't keep them from being easy to input. More on this later.

ANyway, the real data you came here for:

Color	Purpose
Brown	Ground
White	+5v
Red	Clock_in	8
Orange	Strobe_in	9
Yellow	Data_out	10

Button	Bit
Left	1
Right	2
Up	4
Down	8
Select	32
Start	16
B	64
A	128

Note that a clever microcontrollor interface designer can easily multiplex lines to drive both the LCD displays and the NES controllor. I'm sure this is not a accident.