Modern electronic digital computers replace Leibniz 's marbles moving by gravity with shift registers , voltage gradients , and pulses of electrons .
Otherwise computers run roughly as Leibniz envisioned in 1679 .
Modern electronic digital computers replace Leibniz 's marbles moving by gravity with shift registers , voltage gradients , and pulses of electrons , but otherwise they run roughly as Leibniz envisioned in 1679 .