Where and what is the character selection screen and where do I type the code in? I've checked out tons of cheat sites everywhere on the net and for all the cheats it says to type them in at the character selection screen. So I press x on arcade then I go to one player and type in the code at the screen but it never works.

Before you choose your character, press " left,left,right,r2,left,right,right,r1,r1,r2"
It will unlock everything, i've tried it and it works!