@Richard Crowley At the bottom of you page Arduino Playground - PS2Keyboard, there is a link to the latest version of this library "EDITED AGAIN - Actually mostly rewritten - Version 2.0" : PS2Keyboard Library, Connect a keyboard for user input ;
I try with this library from the begining...
On the wiki page, thez say : "The PS2Keyboard library uses one of the two available external interrupts to react on keyboard input. Once such input is received, it's stored in a one-byte buffer and is available to be read."
There is a special PIN on arduino board for interrupt ? Or any digital PIN ?