Comment Starting at logic gates seems arbitrary. (Score 1) 103
I think it makes more sense to start with the "transistor is a switch" level of abstraction. Make some logic gates out of transistors and then go from there. Most people have heard that "computers are made out of transistors" and have probably always wondered where exactly they fit in.
One could try to start even lower, and introduce some basic semiconductor physics--but I'm not sure of a clean of way of introducing those concepts without lying a lot.