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The Origins, Uses, and of the EDVAC

IP.com Disclosure Number: IPCOM000129768D
Original Publication Date: 1993-Apr-30
Included in the Prior Art Database: 2005-Oct-07
Document File: 22 page(s) / 83K

Publishing Venue

Software Patent Institute

Related People

MICHAEL R. WILLIAMS: AUTHOR [+2]

Abstract

The EDVAC computer was the first modem, electronic stored-program computer to be designed. It was, however, never produced to the original plan. When eventually redesigned and constructed, it was unreliable and heavily modified. This article sets out the basic facts about the machine, the uses to which it was put, the software used in an attempt to ensure its reliable operation, and its eventual fate.

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THIS DOCUMENT IS AN APPROXIMATE REPRESENTATION OF THE ORIGINAL.

Copyright ©; 1992 by the Institute of Electrical and Electronics Engineers, Inc. All rights reserved. Used with permission.

The Origins, Uses, and of the EDVAC

MICHAEL R. WILLIAMS

  (Image Omitted: Short preliminary versions of this article have been presented at the New Advances in Computer Science conference held in Graz, Austria, 1991, and at the History of Mathematics Conference held in Baotao, Inner Mongolia, 1991.)

The EDVAC computer was the first modem, electronic stored-program computer to be designed. It was, however, never produced to the original plan. When eventually redesigned and constructed, it was unreliable and heavily modified. This article sets out the basic facts about the machine, the uses to which it was put, the software used in an attempt to ensure its reliable operation, and its eventual fate.

It is well known that the EDVAC was the first general-purpose electronic digital stored-program computer to be designed. This fact is clearly repeated in almost every elementary textbook and, occasionally, even a one-line description of the machine can be found. What is not so easy to find, however, is any indication that the EDVAC was nowhere near the first computer to be operational, was not actually constructed according to the initial design, was not reliable when constructed, and was eventually so heavily modified that it would have been almost unrecognizable to the original design team. This article will set forth the basic facts about EDVAC in the hope that it will serve as a reference point for future investigation into the influence of this machine.

EDVAC origins

In 1944, at the Moore School of Electrical Engineering at the University of Pennsylvania, the world's first large-scale electronic calculating machine was under construction. The ENIAC was a leap forward in calculating technology because its basic building block, the vacuum tube, was thousands of times faster than the electromechanical devices that had been used in earlier machines. It is certainly the case that several other projects (Atanasoff in America and Zuse/Schreyer in Germany, for example) had experimented with the use of vacuum tubes for constructing arithmetic units, but the ENIAC was the first machine to incorporate these high- speed devices into fully functional control and memory elements as well as the arithmetic facilities.

Any of the earlier machines, such as the Zuse, Harvard, or Bell Laboratories devices, that were capable of automatically executing a series of instructions, did so by reading one instruction at a time from long loops of paper tape, executing it, then reading the next instruction. This technique was well known to the major ENIAC designers, J. Presper Eckert and John Mauchly, but had to be replaced by a different control mechanism for the ENIAC. It was a waste of resources to use a mechanism that was only capable of reading, at most, a few instructions p...