I bought it. It doesn't have the PS/2 connector I was hoping to find on it :-) Coming out the back are two nine-line plastic ribbon cables, labelled XT1 and XT2. Before I start pushing electrons through it with the Arduino in the hopes that I can make sense of it, can anyone give me a lead? Ideally someone would say "oh, I know this, it's a <link to manual>", but I'd take informed speculation. My hope is that I'll find the two pins that are the serial connection and I can just wire it up to a PS/2 connector. My fear is that it's current + 8 return pins, and I'll need to decode parallel signals.