Advances in I/O, Speedup, and Universality on Colossus, an Unconventional Computer

Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5715)


Colossus, the first electronic digital (and very unconventional) computer, was not a stored-program general purpose computer in the modern sense, although there are printed claims to the contrary. At least one of these asserts Colossus was a Turing machine. Certainly, an appropriate Turing machine can simulate the operation of Colossus. That is hardly an argument for generality of computation. But this is: a universal Turing machine could have been implemented on a clustering of the ten Colossus machines installed at Bletchley Park, England, by the end of WWII in 1945. Along with the presentation of this result, several improvements in input, output, and speed, within the hardware capability and specification of Colossus are discussed.


Colossus universal computation small UTM preclassical computers 


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  1. 1.
    Andresen, S.L.: Donald Michie: Secrets of Colossus Revealed. IEEE Intelligent Systems, 82–83 (November/December 2001)Google Scholar
  2. 2.
    Beckman, B.: Codebreakers: Arne Beurling and the Swedish Crypto Program during World War II. American Mathematical Society, Providence (2000)zbMATHGoogle Scholar
  3. 3.
    Chandler, W.W.: The Installation and Maintenance of Colossus. IEEE Annals Hist. Computing 5, 260–262 (1983)CrossRefGoogle Scholar
  4. 4.
    Coombs, A.W.M.: The Making of Colossus. IEEE Annals Hist. Computing 5, 253–259 (1983)CrossRefGoogle Scholar
  5. 5.
    Copeland, B.J.: Colossus: Its Origins and Originators. IEEE Annals Hist. Computing 26, 38–45 (2004)MathSciNetCrossRefGoogle Scholar
  6. 6.
    Copeland, B.J.: Personal communication (2005)Google Scholar
  7. 7.
    Copeland, B.J. (ed.): Colossus: the Secrets of Bletchley Park’s Codebreaking Computers. Oxford University Press, Oxford (2006)Google Scholar
  8. 8.
    Cragon, H.G.: From Fish to Colossus. Cragon Books, Dallas (2003)Google Scholar
  9. 9.
    Fant, K., Brandt, S.: Null Convention Logic, a Complete and Consistent Logic for Asynchronous Digital Circuit Synthesis. In: Proceedings of the International Conference on Application Specific Systems, Architectures, and Processors (ASAP 1996), pp. 261–273. IEEE Computer Society Press, Los Alamitos (1996)CrossRefGoogle Scholar
  10. 10.
    Flowers, T.H.: The Design of Colossus. IEEE Annals Hist. Computing 5, 239–252 (1983)CrossRefGoogle Scholar
  11. 11.
    Foundations of Mathematics archive (October 2007),
  12. 12.
    Fox, B., Webb, J.: Colossal Adventures. New Scientist 154/No.2081, 38–43 (1997)Google Scholar
  13. 13.
    Gannon, P.: Colossus: Bletchley Park’s Greatest Secret. Atlantic Books, London (2006)Google Scholar
  14. 14.
    Good, I.J., Michie, D., Timms, G.: General Report on Tunny. National Archives/ Public Records Office, HW 25/4 and HW 25/5 (1945)Google Scholar
  15. 15.
    Good, I.J.: Early Work on Computers at Bletchley. IEEE Annals Hist. Computing 1, 38–48 (1979)CrossRefGoogle Scholar
  16. 16.
    Good, I.J.: Pioneering Work on Computers at Bletchley. In: Metropolis, N., Howlett, J., Rota, G.-C. (eds.) A History of Computing in the Twentieth Century, pp. 31–46. Academic Press, New York (1980)CrossRefGoogle Scholar
  17. 17.
    Herken, R. (ed.): The Universal Turing Machine: A Half-Century Survey, 2nd edn. Springer, New York (1995)zbMATHGoogle Scholar
  18. 18.
    Hewitt, A.: Universal computation with only 6 rules (2007),
  19. 19.
    Sale, T.: Personal communication (2009)Google Scholar
  20. 20.
    Singh, S.: The Code Book. Anchor Books, New York (1999)Google Scholar
  21. 21.
    Small, A.W.: The Special Fish Report (1944)Google Scholar
  22. 22.
    Smith, A.: Universality of Wolfram’s 2, 3 Turing Machine (2008),
  23. 23.
    Tutte, W.T.: FISH and I. Department of Combinatorics and Optimization monograph 98-39, University of Waterloo (1998)Google Scholar
  24. 24.
    Watanabe, S.: 5-Symbol 8-State and 5-Symbol 6-State Universal Turing Machines. J. ACM 8, 476–483 (1961)MathSciNetCrossRefzbMATHGoogle Scholar
  25. 25.
    Watanabe, S.: 4-Symbol 5-State Universal Turing Machines. Journal of the Information Processing Society of Japan 13, 588–592 (1972)Google Scholar
  26. 26.
    Wells, B.: Pseudorecursive Varieties and Their Implications for Word Problems. Doctoral dissertation, University of California Berkeley (1982)Google Scholar
  27. 27.
    Wells, B.: Pseudorecursive Varieties of Semigroups—I. Int. Journal of Algebra and Computation 6, 457–510 (1996)MathSciNetCrossRefzbMATHGoogle Scholar
  28. 28.
    Wells, B.: A Universal Turing Machine Can Run on a Cluster of Colossi. Abstracts Amer. Math. Soc. 25, 441 (2004)Google Scholar
  29. 29.
    Wells, B.: The PC-User’s Guide to Colossus. Invited chapter on the architecture of Colossus in [7], 116–140 (2006)Google Scholar
  30. 30.
    Wolfram, S.: A New Kind of Science. Wolfram Media, Champaign (2002)zbMATHGoogle Scholar
  31. 31.
    Woods, D., Neary, T.: The Complexity of Small Universal Turing Machines: A Survey. Theoretical Computer Science 410, 443–450 (2009)MathSciNetCrossRefzbMATHGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  1. 1.Departments of Computer Science and MathematicsUniversity of San FranciscoSan FranciscoUSA

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