http://en.wikipedia.org/wiki/Reverse_Polish_notation
APL used Reverse Polish notation to control the stack access for the B5000 computer. The B825 was the militarized version of that commercial computer. The B825 used a 4 stack Reverse Polish notation thin film memory design that I used to redesign the communication hub for NORAD to keep track of all the space junk in orbit at the time. It was also used in the guidance system of the ATLAS rocket and the control computer for the DEW line. The DEW Line marked the edge of an electronic grid controlled by the new SAGE (Semi Automatic Ground Environment) computer system and was ultimately centered on the Cheyenne Mountain, Colorado, command hub of the North American Aerospace Defense Command (NORAD). On Wed, Dec 11, 2013 at 11:21 PM, Eric Walker <[email protected]> wrote: > On Tue, Dec 10, 2013 at 5:38 AM, Terry Blanton <[email protected]> wrote: > > >> *A Programming Language (APL) *has an interesting provenance: >> >> http://en.wikipedia.org/wiki/APL_(programming_language) >> > > Here is a simple function from the article that is part of an > implementation of the common "life" program with the mutating lifeforms: > > life←{↑1 ⍵∨.∧3 4=+/,¯1 0 1∘.⊖¯1 0 1∘.⌽⊂⍵} > > > This strikes me more as a mathematical notation than a statement in a > modern programming language. Mathematica statements are much easier to > read. I think there was a special keyboard that allowed you to input each > of these characters. > > Eric > >
