Feynman finite state machine
Your machine outputs the character it just received; Feynman's outputs the previous one.

More specifically, when Feynman's automaton receives the sequence of stimuli $s_1, s_2, \dots$, its output is $x, s_1, s_2, \dots$, where $x=0$ if the automaton starts in state&nbsp;$1$ and $x=1$, otherwise.  Your automaton outputs $s_1, s_2, \dots$ given the same sequence of stimuli.