fun fact: the first mass-produced consumer in-car live navigation (1981) was all dead reckoning and gyroscopes. at this point, the GPS network was operational b

fun fact: the first mass-produced consumer in-car live navigation (1981) was all dead reckoning and gyroscopes. at this point, the GPS network was operational but not available for consumer use until 1988. https://en.wikipedia.org/wiki/Electro_Gyrocator https://en.wikipedia.org/wiki/Electro_Gyrocator