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The Genesis of Microprogramming

IP.com Disclosure Number: IPCOM000129501D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Oct-06
Document File: 4 page(s) / 22K

Publishing Venue

Software Patent Institute

Related People

M. V. WILKES: AUTHOR [+2]

Abstract

Two papers on microprogramming, one from 1951 and one (written with J. B. Stringer) from 1952 are reprinted, along with a retrospective introduction by the author.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 28% of the total text.

Page 1 of 4

THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

Copyright ©; 1986 by the American Federation of Information Processing Societies, Inc. Used with permission.

The Genesis of Microprogramming

M. V. WILKES

(Image Omitted: © 1986 by the American Federation of Information Processing Societies, Inc. Permission to copy without lee 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 the 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: Digital Equipment Corporation, 77 Reed Road, Hudson, MA 01749. © 1986 AFIPS 0164-1239/86/020116-126

The Genesis of Microprogramming

M. V. WILKES .00/00)

Two papers on microprogramming, one from 1951 and one (written with J. B. Stringer) from 1952 are reprinted, along with a retrospective introduction by the author.

Categories and Subject Descriptors: B. 1 [Control Structures and Microprogramming]; C.O [General] -- instruction set design; K.2 [History of Computing] -- hardware General Terms: Design Additional Key Words and Phrases: microprogramming, EDSAC, Cambridge University, Manchester University

Foreword

The ideas underlying the modern stored-program computer were formulated by a small group of mathematicians and engineers who came together at the Moore School of Electrical Engineering in Philadelphia in 1945 and early 1946. These ideas were spread partly by word of mouth, partly by written material, and partly by a course of lectures organized by the Moore School in the late summer of 1946. No one who attended these lectures had any doubt that a stored-program computer could be successfully constructed. However, neither in the lectures nor at any other time was a complete schematic diagram at gate level for such a computer presented. Every group that set out to build a computer had to evolve a design for itself, and it is not surprising that there was much variety in the approaches they took.

The computer with which I was concerned was the EDSAC, built at the Mathematical Laboratory (now the Computer Laboratory) of Cambridge University.

The EDSAC was serial in operation. Its main units were the memory, the arithmetic unit, the input unit, and the output unit, together with a unit known as the main control. These units were interconnected by a bus along which numbers or instructions could be passed. The memory was capable of reading and writing, and the arithmetic unit could perform various operations such as addition, subtraction, and multiplication. The units were conditioned to perform the operation required of them by waveforms emanating from the main control. These waveforms were static; that is, they retained their state -- high or low as the case might be -- for the duration of th...