When I was a kid in the mid/late 80's, our school got some new 80286s I think they were. These were IBMs that came with some sort of optical mouse which needed to be on a special reflective pad which also had a grid on it. Since I haven't been able to get my hands on one now, I was wondering if anyone know how they worked? Were they like the optical mice we have now only less sophisticated? or did they do something different?