BABBAGE,CHARLES ANALYTICAL ENGINE, 1838

Charles Babbage commenced work on the design of the Analytical Engine in 1834, following the collapse of the project to build the Difference Engine. His ideas evolved rapidly, and by 1838, most of the important concepts used in his later designs were established. This paper intro duces the design of the Analytical Engine as it stood in early 1838, c oncentrating on the overall functional organization of the mill (or ce ntral processing portion) and the methods generally used for the basic arithmetic operations of multiplication, division, and signed additio n. The paper describes the working of the mechanisms that Babbage devi sed for storing, transferring, and adding numbers and how they were or ganized together by the microprogrammed control system; the paper also introduces the facilities provided for user-level programming. The in tention of the paper is to show that an automatic computing machine co uld be built using mechanical devices and that Babbage's designs provi de both an effective set of basic mechanisms and a workable organizati on of a complete machine.