[Archduke Tips]

I still don't think we have this thing worked out.

I've never seen a circle used to indicate a closed circuit and a line used to indicate an open circuit.

Also, why would a closed circuit be used to represent off? When the circuit is closed, current has a path to flow...

I would think the circle represents a binary 0 (off) and the line represents a binary 1 (on). One of my professors explained it to me during my freshman year, but I forget what he said.