Codd's Self-Replicating Computer

Abstract

Edgar Codd's 1968 design for a self-replicating cellular automata machine has never been implemented. Partly this is due to its enormous size but we have also identified four problems with the original specification that would prevent it from working. These problems potentially cast doubt on Codd's central assertion, that the 8-state space he presents supports the existence of machines that can act as universal constructors and computers. However all these problems were found to be correctable and we present a complete and functioning implementation after making minor changes to the design and transition table. The body of the final machine occupies an area that is 22,254 cells wide and 55,601 cells high, comprising over 45 million non-zero cells in its unsheathed form. The data tape is 208 million cells long, and self-replication is estimated to take at least 1.7 × 10 18 timesteps.

Determination of one-way bandwidth of cellular automata using Binary Decision Diagrams

“…These newer two-way protocol methods are in the same way limited by the construction of the aggregated transition function, and they can be improved in a similar way; it is somewhat harder, because the two-way protocol takes the receive side configuration into account in a more detailed way. With the progress for bandwidth analysis presented in this paper, it would be also interesting to investigate other twodimensional CAs with more states per cell, including WireWorld or even a universal constructor [12]. Considering the large memory and computation requirements of more complex CAs and investigation depth and width, a parallel implementation of the analysis algorithms would be highly interesting.…”

The Past, Present, and Future of Artificial Life

“…Collaborating with Stanislaw Ulam at Los Alamos National Laboratory, von Neumann defined the concept of cellular automata and proposed a self-replicating formal system, which was aimed at being computationally universal (Turing, 1936) and capable of open-ended evolution (von Neumann, 1966;Mange et al, 2004). Simpler alternatives to von Neumann's "universal constructor" were later proposed by Codd (Hutton, 2010) and Banks (1971). Langton (1984) then proposed simpler self-replicating "loops," based on Codd's ideas but without universality 2 .…”

Self-healing and self-repairing technologies

“…Most of this work was done through software simulations, but practical experiments were done as well. 12 A recurrent cerebellar model articulation controller was developed for the fault-tolerant control of a two-legged robot [153]. An online fault estimation module provides approximation information in case of system failure and modelling error.…”

“…Self-assembly, however, is the main focus of a lot of research [9]. Many projects explore self-replication at micro-and nano-scale [10], in cellular automata (CA) [11] and in computing [12]. Unfortunately, some viruses are even too perfect self-replicators.…”