caa a22 4500 445842911 CHVBK 20180317145350.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s11047-010-9225-x doi (NATIONALLICENCE)springer-10.1007/s11047-010-9225-x Wells Benjamin Departments of Computer Science and Mathematics, University of San Francisco, 2130 Fulton Street, 94117, San Francisco, CA, USA aut Unwinding performance and power on Colossus, an unconventional computer [Elektronische Daten] [Benjamin Wells] In 1944 the computing machine known as Colossus became operational in support of British cryptanalysis and decryption of German High Command wireless traffic. This first electronic digital and very unconventional computer was not a stored-program general purpose computer in today's terms, despite printed claims to the contrary. At least one of these asserts Colossus was a Turing machine. While an appropriate Turing machine can simulate the operation of Colossus, that is not an argument for generality of computation. Nor does the behavior of Colossus resemble that of a Turing machine, much less a universal Turing machine (UTM). Nonetheless, we shall see that a UTM could have been implemented on a clustering of the ten Colossus machines installed at Bletchley Park, England, by the end of WWII in 1945. Improvements require even fewer machines. Several advances in input, output, speed, processing, and applications—within the hardware capability of the time and respectful of the specification of Colossus—are also offered. Springer Science+Business Media B.V., 2010 Colossus nationallicence Universal computation nationallicence Small UTM nationallicence Preclassical computers nationallicence Natural Computing Springer Netherlands 10/4(2011-12-01), 1383-1405 1567-7818 10:4<1383 2011 10 11047 https://doi.org/10.1007/s11047-010-9225-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11047-010-9225-x text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Wells Benjamin Departments of Computer Science and Mathematics, University of San Francisco, 2130 Fulton Street, 94117, San Francisco, CA, USA aut NATIONALLICENCE 773 0- Natural Computing Springer Netherlands 10/4(2011-12-01), 1383-1405 1567-7818 10:4<1383 2011 10 11047 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer