Moore, E. F. [Edward]; Shannon, Claude E. [Elwood]

Reliable Circuits Using Less Reliable Relays [Bell Monograph]

New York: Bell Telephone Laboratories, Inc. January 1957. Later printing. 1-35, [1-blank] pages. 275 x 213 mm (10 7/8 x 8 3/8 inches). Original wrappers printed in grey, light blue, and black. Stapled, with five holes punched at the spine, as issued. A nice clean copy, noting some minor soiling to the rear panel and several creases to the wrappers. Very Good. Wraps. [28167]


The “Journal of the Franklin Institute” first published the two articles collected in this item. “Reliable Circuits Using Less Reliable Relays Part I,“ in Vol. 262 (Sept. 1956), pp. 191-208 and “Reliable Circuits Using Less Reliable Relays Part II,” in Vol. 262, (October 1956), pp 281-297. We are not aware of individual offprints of either paper. However, in October 1956, the “Journal of the Franklin Institute” did publish an offprint containing the first collected edition of these papers. The “Bell Telephone System Technical Publications Monograph” series, #2696: Jan 1957) [as here] constitutes a later printing of the collected edition.

"An investigation is made of relays whose reliability can be described in simple terms by means of probabilities. It is shown that by using a sufficiently large number of these relays in the proper manner, circuits can be built which are arbitrarily reliable, regardless of how unreliable the original relays are. Various properties of these circuits are elucidated." (abstract).

Shannon and Moore immediately credit von Neumann for his work on Sheffer stroke engines, naming that as the inspiration for this paper. They then proceed to perform a similar analysis to relays. They are able to go further than von Neumann in several areas: 1) their methods can be applied to arbitrarily poor relays; 2) they reduce the overall redundancy of a specific von Neumann case from “60,000 to 1” to “67 to 1,” a great improvement, and ; 3) “with the systems described here, this final probability of error can approach zero.”

The authors note, “This paper is not intended for practical design purposes, but rather for theoretical and mathematical insight into the problem. There may, however, be some practical applications.” Applications discussed include large-scale computing machines and areas where human safety is dependent on extreme reliability. They caution that the results are not directly applicable because they used idealized relays whose probability of failure is constant over time, rather than real-world relays that gradually wear out.

A working title for this paper was "Reliable Circuits Using Crummy Relays," which we think is fabulous, but it was changed at the behest of Bell Labs for obvious reasons!

PROVENANCE: The personal files of Claude E. Shannon (unmarked). There were six examples of this item in Shannon's files.

REFERENCES:
Sloane and Wyner, "Claude Elwood Shannon Collected Papers," #89 and #90.

COLLECTORS NOTE: The Bell Telephone System Monograph series offered a way to obtain individual articles by Bell scientists regardless of where their work was first published. Many Monographs significantly postdate the original article publication. Because of this, they rarely constitute the coveted (and traditional) article offprint. If the journal of record issued no offprint, the Monograph might be the first separate publication - the closest the collector can come to a traditional offprint. We have done our best to place each Monograph properly in the article’s publishing history and welcome any corrections or additional information, especially regarding issues unknown to us.

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