NES controller help

[Halogrunt1234]

I have working NES controller and a plug where I can plug th contoller in, complete with the full set of 7 colored wires. Searching online I have learned that I want to power the controller by applying a +5V voltage through pin 1 (white) and grounding pin 7 (brown). I have also learned that the controller sends the data about the buttonpress through pin 4 (yellow) when a clock signal is sent through pin 6 (red). what I don't get is that pin 5 (orange) is labelled "latch" and nothing is ever mentioned on how or why this pin is used. I have set up a solderless breadboard and have applied power correctly, and I have a LED to indicate whether or not a signal is being sent through pin 4. I also have a 555 timer set up to apply a clock pulse to pin 6. I have had no success in actually getting a signal and I still dont understand what the "latch" pin is for.

All I want to do is get a signal from the controller when i press a button. i want the signal displayed as a blinking LED, showing the frequency of the signal.

I will happily accept any help given to me about getting the controller to work without an NES or a computer.

 

[instruite]

**broken link removed**

Latch Pin is used to latch the state of buttons when it is high and when the pulses are sent on pulse pin it reads that that
I guess the change in button state after the latch is made low may not be detectable (I am not sure because I have never used it, others can correct me if I am wrong)

**broken link removed**

 

[Halogrunt1234]

Thank you VERY much for the links. the MIT site was the first one that I came across that decided to actually go in detail in how the controller worked. hmm... now to hook up an IC that will send 12 microsecond pulses...