John Vincent Atanasoff ( ) ADVENT OF THE ELECTRONIC DIGITAL COMPUTING Kiril Boyanov Bulgarian Academy of Sciences

Milestones of digital computing Ancient Abacus B.C. Blaise Pascal Computer – 1642 Gottfried Wilhelm von Leibnitz Computer – 1673 Charles Babbage computer – 1830 Herman Hollerith tabulating machine – 1890 Konrad Zuse electromechanical binary calculating machine – 1931 All these machines are based on mechanical carrier of digital information. No one dared to entrust on carriers other then mechanical one.

Basic concepts of digital computers The first man changed the traditional schema and replace mechanics with electronics was John Atanasoff in1939. In July 1945 Dr. John von Neumann proposed : Stored program concept Paralell mode of storage (storage tube) Parallel procedure in the arithmetic unit, i.e. parallel machine The era of digital computing was started.

John Vincent Atanasoff (circa 1925)

John Vincent Atanasoff (circa 1983)

Personal Data Born on 4 October 1903 in Hamilton, N.Y. His father Ivan Atanasov was a Bulgarian immigrant since 1889, electrical engineer. His mother was Iva Lucena Purdy, a mathematics schoolteacher. In 1926, John Vincent and Lura Meeks were married. Dr. John Vincent Atanasoff died 15 June 1995 of a stroke at his home in Monrovia, Md. He was 91 years old.

John Vincent Atanasoff father’s home in Bulgaria

Educational background Graduated from the University of Florida in 1925 with a Bachelor of Science degree in electrical engineering In 1926 he received his master's degree in mathematics from Iowa State College In 1930 he received a Ph.D. as a theoretic physicist at the University of Wisconsin Associate professor of mathematics and physics at Iowa State College in 1936

Professional Experience Iowa State College, Mathematics, Graduate Assistant and Instructor, University of Wisconsin, Mathematics, Instructor, Iowa State College, Mathematics and Physics, Assistant Professor, Associate Professor, Professor in Absentia,

Professional Experience (continued) Naval Ordnance Lab., Washington, D.C., Chief, Acoustics Section, The Ordnance Engineering Corp., Frederick, MD, Founder, President, Director, Cybernetics, Inc., Frederick, MD, President, Stewart-Warner Corp., Consultant, Control Data Corp., Consultant Honeywell, Consultant,

Honors and Awards U.S. Navy Distinguished Service Award (Navy's highest honor awarded to civilians), 1945 Citation, Seismological Society of America, 1947 Citation, Admiral, Bureau of Ordnance, 1947 Cosmos Club membership, 1957 Order of Cyril and Methodius, First Class, Bulgarian Academy of Sciences (Bulgaria's highest honor accorded a scientist), 1970

Honors and Awards (continued) Iowa Inventors Hall of Fame; Plaque, Iowa State University Physics Building, 1974 Honorary Membership, Society for Computer Medicine, 1974 Doctor of Science, Moravian College, 1981 Distinguished Achievement Citation, Iowa State University Alumni Association, 1983 Order of Peoples Republic of Bulgaria 1 st class Doctor of Science, Western Maryland College; National Medal of Technology given by President George Bush, 1990

The Invention of Digital Computer After examining many mathematical devices available at the time, Atanasoff concluded that they fell into two classes--analog and digital (what he called "computing machines proper“). He believed that analog devices were too restrictive and could not get the type of accuracy he wanted. The idea of building an electronic digital computer came to him while he was sitting in a tavern (he had a drink of bourbon). As Dr. Atanasoff worked on his computer project, he asked a colleague to recommend a graduate student to assist him with his project. The graduate student that was introduced to him was Clifford Berry. From 1939 until 1941 they worked at developing and improving the ABC, Atanasoff-Berry Computer

The Atanasoff-Berry Computer (ABC) was the first electronic digital computer

Clifford Berry with the ABC (1942)

Photo of completed replica of ABC The original ABC was dismantled decades ago. Ames Laboratory, using private funding, builds a working replica of this historically important invention.

FOREGROUND: Newly constructed base two punch drive electronics. BACKGROUND: Newly constructed base two punch high voltage transformer chassis. The ABC pictures

The ABC pictures (continued) FOREGROUND: Old parts acquired for construction of ABC (note vacuum tubes and connector from the 1940s, telephone switches and panel meter). BACKGROUND: Newly constructed parts

The ABC pictures (continued) The only surviving fragment of the original ABC built in This drum holds 30 numbers of 50 bits each. (Two of the columns are spares). They are operated on in parallel. It is the first use of the idea we now call "DRAM" - use of capacitors to store 0s and 1s, refreshing their state periodically.

The ABC pictures (continued) Close view of base two punch /reader from left of frame.

The ABC pictures (continued) FOREGROUND: Newly constructed Add- Subtract Module (ASM) showing seven vacuum tubes (6C8). BACKGROUND: Bottom view of newly constructed ASM being tested with connection to model computer.

Diagram of ABC computer

Block diagram of ABC computer Each of the two drum memories (Drum #1 and Drum #2) stores 30 numbers by 50 bits Each drum memory contains 30 disks with 50 capacitors ACM is a serial Add- Subtract Module In the ABC there are 30 independent ACM’s for each couple of drum memory numbers The first computer is also the first realization of the SIMD (Single Instruction Multiple Data) concept. Card PuncherCard Reader 30 ASM’s Drum #2 (ka) 30 Drum #1 (ca) 30

Dr. Atanasoff’s four principles for electronic digital computer He would use electricity and electronics as the medium for the computer. In spite of custom, he would use base-two numbers (the binary system for his computer. He would use condensers for memory and would use a regenerative or "jogging" process to avoid lapses that might be caused by leakage of power. He would compute by direct logical action and not by enumeration as used in analog calculating devices. (Mollenhoff, 34)

Dr. Atanasoff - the inventor of the electronic digital computer In 1940 Dr. Mauchly wanted to see the ABC for himself and Dr. Atanasoff agreed. Dr. Mauchly later used many of Dr. Atanasoff's ideas in the design of the ENIAC, that was falsely considered as the world's first electronic digital computer designed by Dr. Mauchly and Dr. Eckert. Charges of piracy were later brought against Dr. Mauchly, co-inventor of the ENIAC. U.S. District Judge Earl R. Larson ruled that the ENIAC was "derived" from the ideas of Dr. Atanasoff. When the trial finally ended, Dr. Atanasoff was given credit as the inventor of the electronic digital computer.

The facts about trial 1967Charles Gall – the first lawyer of Honeywell controversy Sperry Corporation over ENIAC patents. Allan Kirkpatrick would do the early interview and deposition work for Control Data. 1968Lawyers for Honeywell and control Data issued subpoenas for all the relevant records from the files of Sperry Rand, IBM and Moore School Electrical Engineering. 1968The jurisdiction was finally placed in Minnesota and Earl B. Larson took the jurisdiction. 1971On June, 1 st Earl Larson starts the trial. 1973On October 19 th Publication of the decision.

Excerpt from trial verdict 3.1The subject matter of one or more claims of ENIAC was derived from Atanasoff, and the invention claimed in the ENIAC was derived from Atanasoff Eckert and Mauchly did not themselves first invent the automatic electronic digital computer, but instead derived that subject matter from one Dr. John Vincent Atanasoff Although not necessary to the finding of derivation of “the invention” of ENIAC patent, Honeywell has proved that the claimed subject matter of the ENIAC patent on in support of the counterclaim herein is not patentable over the subject matter derived by Mauchly from Atanasoff. As a representative example, Honeywell has shown that the subject matter of detailed claims 88 and 89 of ENIAC patent corresponds to the work of Atanasoff which was known to Mauchly before any effort pertinent to ENIAC machine or patent began In December, 1940, Atanasoff first met Mauchly while attending a meeting of American Association for the Advancement of Science in Philadelphia, and generally informed Mauchly about computing machine which was under construction at Iowa State College. Because of Mauchly’s expression of interest in the machine and its principles, Atanasoff invited Mauchly to come to Ames, Iowa, to learn more about the computer.

The Road to the Digital Future When John Vincent Atanasoff invented the computer, he probably did not know how much of an impact it would have on people's lives. Computers will be involved in every aspect of technology, and it will continue to be a part of technologies to come. The capabilities of computers are advancing every day. Computers will always be on the edge of technology and anyone that learns to harness its power will be an important part of the future. Every aspect of our lives has changed because on the computer and its inventor, John Vincent Atanasoff.

REFERENCES Clark R. Mollenhoff, Atanasoff, Forgotten Father of the Computer, ISU Press, (Hien Chris Do) Atanasoff, J.V., Computing Machine for the Solution of Large Systems of Linear Algebraic Equations, The Origins of Digital Computers, Selected Papers. Randell (ed.), New York, Springer-Verlag, 1973, Chapter 7.2. Blagovest Sendov, John Atanasoff,The Electronic Prometheus, St.Kliment Ohridski University Press, Sofia 2003