Iter Avto (Onboard Navigation)
The Iter Avto, which used a map on a scroll, is believed to be the first onboard direction guide. The principle is quite simple. The screen manually scrolls paper maps that are attached to a cable that similar to a modern mechanical speedometer. How fast the map rolls as projected on the screen depends on the vehicle’s speed. The only problem was, if you needed to make a turn to a new street, you’d have to find the map for that street and switch it in mere seconds.