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Anecdotes (HTML)
October-December 2005 (vol. 27 no. 4)
pp. 89-92
Laurie Robertson, Editor, Virginia Tech

Reflections on the Difference Engine

Andrew Booth
Doron Swade's description of the reconstruction of Babbage's Difference Engine at the Science Museum in London prompted some questions: Why didn't Babbage use binary arithmetic? Why didn't Babbage use the electromagnetic relay, which Morse had already invented? These lead to a description of the ARC relay machine at the University of London and to a brief account of its simultaneous carry that gave Babbage such problems.

The Founders of the ACM

Eric A. Weiss
This article provides brief sketches of the eight men who founded the ACM in 1947, along with their backgrounds and later careers. The article also includes the 1972 Silver Anniversary speech by the singular founder, Edmund. C. Berkeley, and discusses its immediate consequences.

1. D. Swade, The Difference Engine, Viking, 2001.
2. S.F.B. Morse's, Letters and Journals (chap. 2, 1836) was quoted in R.L. Peek and H.N. Wagar, Switching Relay Design, Van Nostrand, 1955, p. 2 para.1.2.
3. A.D. Booth, "A Magnetic Drum Storage System," Electronic Engineering no. 21,, Jul. 1949, p. 234.
4. H.B. Mohanti and A.D. Booth, "A Simple Electronic Fourier Synthesizer," J. Sci. Instr., vol 32, Nov. 1958, pp.442-444.
1. The original article F.L. Alt, "Fifteen Years ACM," Comm. ACM, vol. 5, no. 6, June 1962, pp. 300-307, was reprinted in vol. 30, no. 10, Oct. 1987, pp. 850-857.
2. "Notice on Organization of an Eastern Association for Computing Machinery," dated "June 25, 1947." ACM Headquarters has a copy of this mimeographed document, but it is not known whether any of the original sheets survived. A collection of Berkeley's papers, recently auctioned by Christie's, did not include one.
3. Computerworld, vol. VI, no. 34, 23 Aug. 1972, front page.

Index Terms:
Charles Babbage, Difference Engine, ARC relay machine, ACM, Association for Computing Machinery, Eastern Association for Computing Machinery, E.C. Berkeley, R.V.D. Campbell, J.H. Curtiss, H. E. Goheen, J.W. Mauchly, T.K. Sharpless, R. Taylor, C. B. Tompkins
Laurie Robertson, "Anecdotes," IEEE Annals of the History of Computing, vol. 27, no. 4, pp. 89-92, Oct.-Dec. 2005, doi:10.1109/MAHC.2005.53
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