Modern avionics, whether an EFIS display, a navigator or even a traffic system—in fact just about all electronics today—are little more than computers with some local inputs, some remote inputs, an output device and some remote outputs. That’s it.
Think about today’s sophisticated navigator. Start with the computer. That computer needs inputs—some buttons and probably a touch screen. Other local inputs include a means to get aviation database(s), a GPS engine that provides precise position data, and receivers for VOR, LOC and glideslope. Inputs for remotely provided data might include things like barometric pressure, fuel flow and data for weather, traffic and the like. Outputs include the local display and externally providing data from the GPS and the databases. (Yes, this is an oversimplification, but not by too much.)
