In Paris, we used to have special boards at big stations: a map of the subway system, and a button board with one button per station in the city; if you pressed

In Paris, we used to have special boards at big stations: a map of the subway system, and a button board with one button per station in the city; if you pressed a button, the path would light on the map explaining how to reach it: https://spacefiction.files.wordpress.com/2017/11/indicateur_itineraires.jpg https://spacefiction.files.wordpress.com/2017/11/indicateur_... Those appeared in 1937, so they're very old tech; it would be fun to have a pocket version. They've since disappeared and been replaced by touch screens, but those are just not the same. https://spacefiction.fr/2017/11/06/patrick-modiano-et-la-memoire-des-panneaux-indicateurs-lumineux-ditineraires-de-la-ratp-patrick-modiano-and-the-memory-of-ratp-illuminated-itineraries-panels/ https://spacefiction.fr/2017/11/06/patrick-modiano-et-la-mem...