I use to listen to C-net Radio, back when they had such a thing. I remember them talking about the development of the "nav" system. one guy had a tablet pc from like 95 and he had a kit installed on his car that tracked when it turned and how far it drove and with that information, and a preprogrammed starting location it could accurately give your location. If i remember correctly he said the kit came from a cop car.

I miss C-net Radio

__________________