plug two playstation controllers into one input?

[ZippyDan]

me and my brother have a tradition of playing the final fantasy games together... ff4, 5, and 6 particularly.  generally, we each get a 'character' and when its that character's turn to fight, you go

unfortunately, ff7, 8, 9, 10 are one player games only, with no support for two controllers. so i was thinking of buying two PS2 extension cables, and splicing them together so i could plug two controllers into the 1st player input and that might maybe work to allow us to both control the game.

however, i am wondering if this could possibly damage the ps2 and/or controllers (too much voltage, too little voltage, short circuit... i dont know too much about emag so i have no idea what im saying really).  at another forum someone said it might create overcurrent.  on that note, anyone know where i could find a wiring diagram for the ps2 controller cables?

another idea was to get two wireless controllers and set them to same frequency, but apparently this doesnt work very well as the controllers continue sending stuff even when u are not pressing buttons

ive also found that there is some 'protocol' for communication, so splicing cables wont work without some kind of intelligent adaptor...  is this true?

finally, any chance that there is already a product that will do this for me?

thx

~Zippy!  

[hemphacker]

At first thought, I don't think the splicing 2 cables together won't work due to the protocal, but an idea would be to butcher some controllers so that the switches from the buttons on 2 controllers bypass all the other circuitry and are wired (in parrallel) to the buttons on a 3rd controller that plugs into the console. This way both controllers will work simultaneously on one port.

[gannon]

You could do this, but you'd need to put a switch in the power line of the controllers to switch between them. Otherwise the playstation will be receiving signals that contradict eachother.  

[Guest]

This is kinda off topic, but in FF9 there is an option to set each character to a 2nd controller. Try looking in the settings Hope I helped!

[VPCoder]

Switching the power is not really good idea, erghhh (what a bad idea). If you want to switch in a good way, then do it through the select pins ATT of both controllers.

But I say (without any guarantee) it should be possible to connect the signals without any splitting, because the signals DATA and ACKNOWLEDGE both are open collector. This means, there is no short circuit if the one DATA is high and the other DATA is low.

All the buttons are low active, that means, the button bits in the protocol are only high if none of the pad buttons are pressed.

I think it should work. But there are two restrictions which are important :

1. Don't use analogue mode of game pad
2. Both game pads has to be exactly the same controller type

If this don't work, then switch the low active ATT signal with a toggle-ff to select one time the pad 1 and the other time pad 2. But don't switch the power because you don't know, how long the controller has to initialise. Perhaps it needs longer than the playstation waits for timeout.

Hope this helps
Greets VPCoder