Gz wrote: "Anyway, the 1 is referenced to the ON state. 0 is OFF state. The ONLY two
states in most systems. But I also had to learn General Dynamics, dynamic
logic. ON was a pulse, OFF was no pulse. "

Honestly, I thought they stood for (I)n - as
in current flowing through the circuit, and
(O)ut - as in current blocked - not flowing.