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Charles Babbage's Analytical Engine, 1838

IP.com Disclosure Number: IPCOM000129393D
Original Publication Date: 1982-Jul-01
Included in the Prior Art Database: 2005-Oct-05
Document File: 23 page(s) / 84K

Publishing Venue

Software Patent Institute

Related People

ALLAN G. BROMLEY: AUTHOR [+2]

Abstract

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 introduces the design of the Analytical Engine as it stood in early 1838, concentrating on the overall functional organization of the mill (or central processing portion) and the methods generally used for the basic arithmetic operations of multiplication, division, and signed addition. The paper describes the working of the mechanisms that Babbage devised for storing, transferring, and adding numbers and how they were organized together by the ";microprogrammed"; control system; the paper also introduces the facilities provided for user-level programming. The intention of the paper is to show that an automatic computing machine could be built using mechanical devices, and that Babbage's designs provide both an effective set of basic mechanisms and a workable organization of a complete machine.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

Copyright ©; 1982 by the American Federation of Information Processing Societies, Inc. Used with permission.

Charles Babbage's Analytical Engine, 1838

ALLAN G. BROMLEY

(Image Omitted: © 1982 by the American Federation of Information Processing Societies, Inc. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the AFIPS copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of the American Federation of Information Processing Societies, Inc. To copy otherwise, or to republish, requires specific permission. Author's Address: Basser Department of Computer Science, Madsen Building FOG, University of Sydney, NSW 2006, Australia. © 1982 AFIPS 0164-1239/82/030196-217

Charles Babbage's Analytical Engine, 1838

ALLAN G. BROMLEY .00/00)

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 introduces the design of the Analytical Engine as it stood in early 1838, concentrating on the overall functional organization of the mill (or central processing portion) and the methods generally used for the basic arithmetic operations of multiplication, division, and signed addition. The paper describes the working of the mechanisms that Babbage devised for storing, transferring, and adding numbers and how they were organized together by the "microprogrammed" control system; the paper also introduces the facilities provided for user- level programming. The intention of the paper is to show that an automatic computing machine could be built using mechanical devices, and that Babbage's designs provide both an effective set of basic mechanisms and a workable organization of a complete machine.

Categories and Subject Descriptors: K.2 [History of Computing] -- C. Babbage, hardware, software General Terms: Design Additional Key Words and Phrases: Analytical Engine

1. Introduction

Charles Babbage commenced work on the design of the Analytical Engine shortly after the collapse in 1833 of the 10-year project to build the Difference Engine. He was at the time 42 years old.l1

Progress on the Analytical Engine went rapidly. The first notes appeared in mid-1834, and by mid-1836 a workable design had evolved. A major revision of the design took place in late 1837. For the next decade work on the Analytical Engine consisted largely of refinement and elaboration of the basic design of 1837-1838. During this period Babbage appears to have

1 1 For a thorough account of the history of Babbage's involvement with the design of calculating machines, see Copier (1970) and Hyman (1982).

IEEE Computer Society, Jul 01, 1982 Page 1 ...