In 1204.4926 the idea is that a quantum oscillator is actually a discrete deterministic system that cycles through a finite number of states. Then in 1205.4107 he maps a cellular automaton onto a free field theory made out of coupled quantum oscillators. Then in 1207.3612 he adds boolean variables to his CA (previously the cells were integer-valued) in order to add fermionic fields. At this point his CA is looking a little like a superstring, which from a "worldsheet" perspective is a line with bosonic and fermionic quantum fields on it. But there are still many issues whose resolution needs to be worked out.