Archive for October, 2011

Cyber war: myth or reality?

October 17, 2011 1 comment

A great advantage of having many faculties on one campus is that you can get to interact with people with quite different perspectives who are interested in similar real-world issues. Today I spent a refreshing hour in the company of Thomas Rid, one of several War Studies colleagues who, like a few of us Informaticians, wants to understand whether cyber war is just another kind of warfare in a new domain (after land, sea, air and space), or whether it falls outside Clausewitz’s three characteristics of warfare (violent, instrumental and political). Thomas has already blogged about his article on Kings of War: and I wanted to probe and test his contentions with possible cyber counter-examples for each of the three characteristics.  Since our offices are just the length of a corridor apart it’s easy to have these impromptu get-togethers over a freshly brewed coffee (thanks, Thomas!). And it appears that there may be rather more to this issue than initially meets the eye – watch this space for developments as they happen!

Categories: Security

Reverse Polish Notation (RPN)

October 8, 2011 Leave a comment

The Financial Times recently published a correspondence on Reverse Polish Notation, including this letter from one Peter Jaeger of Tokyo, Japan (published on 2011-09-30):

Sir, Your reader Chris Ludlam describes the input method of his HP12c as “reverse logic”. The correct term is “Reverse Polish”, which is not only far more colourful, but also gives credit to Jan Lukasiewicz, the logician who invented the original Polish Notation which American mathematicians later adapted for computers.”

While it is correct to say that American mathematicians adapted Reverse Polish Notation (RPN) for computers, this is not the whole story.  The first person to speak publicly about using RPN for computer architectures was Australian –  Charles Hamblin, an Australian philosopher and computer pioneer, speaking at a computer conference held in Salisbury, South Australia, in June 1957.  (This was billed as “The First Australian Computer Conference”, but an earlier one had been held in 1951.)   Hamblin’s work was published in the conference proceedings and later in a refereed article in the Computer Journal in 1962.   Among the attendees at that conference was the British statistician and computer pioneer Maurice Wilkes, who later won an AM Turing Award (in 1967), as well as delegates from computer manufacturing companies.

The first computer manufacturing company to announce deployment of RPN in a commercial computer architecture was British – the English Electric Company (EEC), in their KDF9 machine, announced in 1960 and delivered in 1963.   Burroughs, an American computer company, also delivered a computer using RPN in 1963, the Burroughs B5000, but this machine was only announced in 1961.   Robert Barton, chief architect of the B5000, later wrote that he developed RPN independently of Hamblin, sometime in 1958.

So the first person to talk publicly about applying RPN to computers was Australian and the first computer company to say publicly they would actually do so was British.   Not everything in computing happens first in the USA!


R. S. Barton [1970]: Ideas for computer systems organization: a personal survey. pp. 7-16 of: J. S. Jou (Editor): Software Engineering: Volume 1: Proceedings of the Third Symposium on Computer and Information Sciences held in Miami Beach, Florida, December 1969. New York, NY, USA: Academic Press.

C. L. Hamblin [1957]: An addressless coding scheme based on mathematical notation. Proceedings of the First Australian Conference on Computing and Data Processing, Salisbury, South Australia: Weapons Research Establishment, June 1957.

C. L. Hamblin [1962]: Translation to and from Polish notation. Computer Journal, 5: 210-213.

Categories: AI, History, Logic
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