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Early Electronic Computers

The Birth of Electronic Computers

Konrad Zuse

Konrad Zuse has been credited credited with engineering the world's first binary digital computer. This first computer was developed from 1936 to 1938 and was called the V1 by Zuse (a name that he changed to the Z1 later.) This was the first of four "Z" class machines that Zuse built in German during World War II. Read the essay by Raul Rojas to discover the engineering details of the computers Zuse built.

The Colossus

Alan Turing is often associated with the creating of the Colossus, a top secret computing project designed in England during the second World War. While Turing was involved with the code breaking efforts of Bletchley Park, it was under the leadership of Tommy Flowers that the Colossus was built.

Eventually ten Colossus computers were built.

A picture of Alan Turing and the Colossus

The Colossus Rebuild Project

The Alan Turing Home Page

Howard Aiken

In 1937 Howard Aiken was a graduate student and an instructor in the Department of Physics at Harvard University when he received funding from IBM to develop a new calculating machine. He used more that 760,000 relays, switches, wires and panels to combine 78 adding machines and desk calculators into a single caclulating unit controlled by instructions recorded on punched paper tape. The result of using both electronic and mechanical parts means that the Mark I is classed as an electro-mechanical computer. This machine was officially called the Automatic Sequence Controlled Calculator (or ASCC) but is commonly refered to as the Mark I (picture).
Completed by 1944 this first general purpose computer could multiply two numbers in three seconds. In 1947 the Mark II was revealed. It was three times the size of the earlier computer and as a fully electronic computer it had 12 times the speed of the Mark I

Atanasoff and Berry

John Vincent Atanasoff was a professor of physics and mathematics at Iowa State when he began to search for a way to relieve the tedium of solving simultaneous equations in 1939. Working with Clifford Berry, a graduate student, Atanasoff built the first electronic digital computer, the ABC (or Atanasoff-Berry Computer from 1939 to 1942.
Further references John Atanasof and Clifford Berry and the ABC.
Visit this site for the Reconstruction of the Atanasoff-Berry Computer (ABC)
Be sure to read about the controversy between Atanasoff and Mauchly.

John Mauchly and J. Presper Eckert and the ENIAC

It was not long after Mauchly had visited with Atanasoff that the events of World War II pushed the development of computing devices in a new direction. One urgent need for better methods of calculation came from the Army which needed to produce new sets of ballistic tables that gunners used to aim large artillery pieces. Dr. Herman Goldstine, then a lieutenant in the US Army, approached Professor John Mauchly at the Moore School of Engineering, about building an electronic computing machine. Mauchly eagerly undertook the project taking on as the chief engineer.

The ENIAC or Electronic Numerical Integrator and Computer was introduced to the public in 1946.

The secret mission of the first computer programmers is a must read article that reveals a behind-the-scenes perspective on the creation of the ENIAC.

Also take a look at Past Notable Women of Computing & Mathematics which has information about the women involved in the ENIAC and UNIVAC projects.

"Information about the history of computing, assembled by Mike Muuss for your information and edification."

John von Neuman

As one of the leading mathematicians of the day, von Neuman, joined the ENIAC team in 1944. Together the three men began to see a better way to engineer nearly every aspect of the ENAIC. Von Neuman wrote the First Draft of a paper that presented most of these ideas. Unfortunately only his name was recorded on the paper, leaving no credit to Eckert and Mauchly for their contribution.

John von Neuman went on to build the EDVAC or Electronic Discrete Variable Automatic Computer at the Moore School between 1947 and 1950. It is for this work that the fundamental engineering desings for modern computers is called von Neuman Architecture.

Note the article at John von Neumann and von Neumann Architecture for Computers.


Meanwhile Eckert and Mauchly had resigned from the Moore School and opened the very first commercial computer company. It was called the Eckert and Mauchly Computer company. Their first computer was the UNIVAC or Universal Automatic Computer.

Here are a few resources about the UNIVAC

The Commercial Computer Industry

Read a summary of how the UNIVAC and other computers formed the early computer industry.

Here is an overview of the Four Generations of Computer Hardware.

The Jones Telecommunications & Multimedia Encyclopedia describes The Five Generations of Modern Computers

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