sentences:  Hence, while all the configurations given here can construct any passive configuration, none can construct the real-time crossing organ devised by Gorman.All the implementations of von Neumann's self-reproducing machine require considerable resources to run on computer.For example, in the Nobili-Pesavento 32-state implementation shown above, while the body of the machine is just 6,329 non-empty cells (within a rectangle of size 97x170), it requires a tape that is 145,315 cells long, and takes 63 billion timesteps to replicate.