I'm stuck at Arris Dome (Solved!)

[Gray]

I've been stuck for some time around this area- but hear me out. I DID in fact catch the rat. Whom gave me the code for the system below. I successfully hit 'A' at the console, it replied with one positive note. I put in the proper code, and it replied with what I can only describe as the 'yes that's correct' noise. Nothing else happens. I started at the console to the right, but have also used the one on the left many times. I cannot reach the door to the right. I've checked out multiple guides on this issue. The rat had me press 'Y', 'B', and 'A' all at the same time, which resulted in the aforementioned 'correct' sound. I also read about the 'R', 'B', and 'A' combo. This also lead to a 'correct' sound, but still nothing happens. On the outer map, if I go to the North to Site Something-Or-Other, I also cannot pass. I get to the futuristic-looking car, but nothing happens even after vigorous attempts at searching the car. I've also passed through the sewers, reaching that strange lab on the other side. It contains an 'Old Man' and his eggplant-like construct. Can't do anything there either. Death Peak is a dead end. Going backwards also leads to nothing. According to various FAQ's, I should be able to access that door in the Arris Dome after putting in the code. I read about having to have Marle's hairpin, but I have not found Marle's hairpin, or have seen what it does. Halp!

[Twinkie]

You have to input the code to progress through the game. It might be a bit more difficult if you are not using a controller or something. Just keep trying at the code, and eventually the path to the door WILL open. Otherwise you can't get any farther.

[Gray]

I am indeed using a controller. I have repeatedly used the code on both the right and left console, and the secondary code I've listed above. What am I doing wrong?

[Gray]

Alright guys, I have found the solution. After the you hit the button with 'A', you have to press all 3 buttons at once, 3 times rapidly in a row. This was very confusing. I hope this will help anyone else having the same problem.