Mame Controller (PS2 Multitap)

I am trying to make a 4 player wireless Mame controller.
I would like to use one Arduino Uno, four wireless PS2 controllers, and a PS/2 USB adapter. So far I have got the Arduino talking to the PC via the PS/2 keyboard interface.

I was wondering if anyone has interfaced a PS2 multitap with an Arduino before, and if there is a library that supports it. Or some other way to attach four PS2 controllers to a standard Uno