Emulating a SNES controller

So I want to have my arduino uno act as if it is a snes controller, I know there have been projects where people hook up a snes controller to the arduino and use it but I cannot find a project that is the other way around. I don't have a oscilloscope so its hard to see what the arduino is doing. I have tried two methods but I cannot get the timing right, there seems to be just too much variance when it comes to stuff with the arduino. at first I think it was too slow to keep up with the console so I used port manipulation which was fast enough but by the time the arduino realizes it is supposed to send the inputs some weird ammount of time has already passed. how would I fix this?

link to how the controllers work (scroll down to the controller section) http://www.gamefaqs.com/snes/916396-super-nintendo/faqs/5395