For PSX, you need to enable multitap. Run any PS1 game then tap on retroarch icon. Then go to options then enable multitap 1. Restart the game. Make sure to turn it back to auto before you playing 99 studio games, because game will not respond to controller. this is unknown issue.
I tried your method but, is not working. Quite weird… what could it be? Did you tried this with what core? I tried with Snes9x
I´ll try with PSX and i tell you.
Okey, yes its working but i need to press the buttons like hundred times to move. So, i’ll classified it as partially working. Need more testers, who else can help us trying his method
I tried PSX, PC engine and Snes9x and they are working fine. To fix your problem just delete config file. Start up again input all the buttons. Make iCade on user 3 port#0. Make sure that you can’t insert both select and start buttons. If you able to insert start and select your controller may not be on icade mode. Pc engine you can play more than 2 players without any additional settings. for PSX you need to enable mutitap 1 then start any game again, then tap on retroarch icon. after that, this time go Controls, make sure all device type selected to “RetroPad” not Unknown. For Snes9x same psx, start any game, then tap on retroarch icon. after that, go to Controls, Make sure all devices type selected to “RetroPad” except User 2 Device type to “Multitap”. Done.
You can’t do that, since its already an iCade controller. I can’t change the way it works. But i’ll try to change the iCade input controller type to another instead of the Snes 8Bitdo. And thanks, i’ll tell you if it worked.
iOS devices only support iCade mode. What i mean, is that you can change the controller type inside Retroarch.
iOS supports keyboard mode as well.
I know, but this is not for what i’d like to use it for.
Hey, Mr. Seven. What mode does your controller use, its Keyboard or iCade? Maybe that might help to understand why yours is working.
My controller connected on iCade mode. To test your controller go to notes app Then try these buttons and if it gives other than these letter that means your controller are not connected on iCade mode.
Up = we Down = xz Right = dc Left = aq
Do you know to recommend a specific icade controller or is it indifferent? I read that buttons start and select don’t work, how can I solve it? maybe with on-screen buttons? but if I press the little keyboard on the bottom of the screen to clear it, I don’t know how to make reappear it. Best regards.
I highly recommend 8bitdo Snes series. This model do the job, also, start and select buttons work with emulators like SNES9AX and Retroarch. Not with iCade games. Also, if you will be using it with iphone you can buy the xtander.
I’d suggest checking youtube for reviews with much more devices than just the one i have. Go check it just to assure what you really want.
To be honest I don’t recommend any iCade controller because it’s good for iOS 6 and lower. After iOS 7 with MFI feature, the best option to go with MFI controllers. MFI controller good for iOS games, emulators and offline multiplayer. I know icade cheaper but you won’t use it that much unlike the MFI. Also there is no left analog so you will not be able to play N64 games. For overlay (virtual controller) just kill the app by double click on home button then swip retroarch up. It will reappear.
He´s right, MFI is much better. And if would you like a reccomendation to that, i´d suggest the Nimbus Steelseries. He has that one, either. Its an amazing device, cost like about 60bucks, the same as the iCade i use (which is a recomendable device if you want an iCade 
) . But with this one you can use more than one with no issues. Just remeber that start and select doesnt work with MFI. You have to use other buttons to make them work.
8Bitdo is an amazing brand, you should try it. Much better than traditional iCade devices. Trust me, this thing might change your opinion. But at the end of the day, MFI is much better. No doubt about that. By the way, you use Nimbus (Steelseries) MFI controller, right?
Right, my controller is Nimbus Steelseries. For start and select, I use menu button for start and right analog (left) for select and left analog(right) for menu toggle. I wish they add new feature to create your own combo buttons for example, (menu + L1 ) replace select button and (menu + R1) replace menu toggle. Right now I only can use combo for menu toggle (Down + R1 + L1 + Y) on nimbus controller Y = X
maybe idiot question: is there a way to connect ps3 controller at ipad without jailbreak?