A versatile keyboard input and output device is described. For example, the location of a remote object may be determined via a first bearing, at a first location, and a second bearing, at a second location, to the remote object. This asymmetry can then be measured by measuring the diffraction spectra of radiation reflected from the overlay target. A drive counter is downcounted every 200 cycles, while the drive counter is upcounted in accordance with the number of drive pulses DRIVE. Geo-stamped images of signposts of the series of signposts having the common signpost content are then displayed in a motor vehicle. Related apparatus and methods are also described.