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Ubiquity symposium: What have we said about computation?
closing statement

Ubiquity, Volume 2011 Issue April, April 2011 | BY Peter J. Denning 


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6 Feb 2016 I agree that it is good to study interactive systems. For example, at a microcode level, a CPU consists of two or more interacting systems. See, for example, Andrew Tanembaum's account in his book on computer organisation from around 1979. Wegner says that interaction is more powerful than algorithms. But an interactive system is implementing an algorithm. A microcoded Turing machine would consist of interacting processes just as surely as a CPU has operations on an address bus and a data bus. Perhaps all Wegner is saying is that concurrent programs are a good thing. Dijkstra and Wirth wrote on this in the 1960's. Michael Arbib invented a concurrent design for Honeywell while on a vacation job in 1960. Charles Simonyi and Per Brinch Hansen invented a concurrent processing system for a a 4kb computer in a weekend in 1964. Ken Thompson invented Unix in 1969 so he could run a moonlander game which (presumably) previously ran in PL/I. PL/I allows mulitasking. thing, as do the Burroughs versions of Algol, Fortran, Cobol, and PL/I from the early 1970's.

��� richard mullins, Fri, 05 Feb 2016 21:59:31 UTC

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