MIT5312: Systems Analysis and Design
Spring, 200

What were the first computers?

That may sound like a very easy question, but it isn't. As we have already seen, many people feel that Zuse's machines were the first computer(s). However (again, as noted earlier), there is one simple criterion which defines what a computer is:

It is electronic (it has no moving parts)

 It has also become a legal question (as we shall see).

We need to put ourselves back in time to get a feel for what was happening. Imagine yourself in the late 1930's:

 -- 1936 --

Hitler and Mussolini formed a military alliance called the "Rome-Berlin Axis" and began referring to themselves as the axis powers.

-- 1938 --


Threats from both Hitler and Mussolini forced the Austrian government to include Nazi members it's cabinet


In April, Mussolini invades Albania


In September, Hitler demands that Sudetenland be turned over to Germany, and if not he threatened to take it by force

The United States was feeling a little uneasy. As a result, the Department of War (No, that is not a misprint; it was the Department of War then) contacted the leading computer scientists and provided funding to help develop machines that would quickly calculate missile trajectories (as well as other calculations). In particular, three institutes were contacted:

1.  Iowa State University (Atanasoff and Berry):

The Atanasoff Berry Computer (ABC)  incorporated several major innovations in computing including the use of binary arithmetic, regenerative memory, parallel processing, and separation of memory and computing functions. Atanasoff built the device in the basement of the university's physics building with the collaboration of graduate student Clifford Berry. In November 1939 they demonstrated its ability to expand manyfold the power of physical computation while removing the drudgery.

2.  Harvard University (Howard Aiken):

The Mark I was constructed out of switches, relays, rotating shafts, and clutches, and was described as sounding like a "roomful of ladies knitting." The machine contained more than 750,000 components, was 50 feet long, 8 feet tall, and weighed approximately 5 tons!

Its architecture was significantly different from modern machines. The device consisted of many calculators which worked on parts of the same problem under the guidance of a single control unit. Instructions were read in on paper tape, data was provided on punched cards, and the device could only perform operations in the sequence in which they were received.

2.  The University of Pennsylvania (Eckert and Mauchly):

On June 5, 1943, the DOW signed a new contract with the Moore School of Electrical Engineering to research, design, and build an electronic numerical integrator and computer -- ENIAC. It was to be supervised by Professor Brainard, with Dr. Eckert as chief engineer, and Dr. Mauchly as principal consultant.

The machine designed by Drs. Eckert and Mauchly was a monstrosity. When it was finished, the ENIAC filled an entire room, weighed thirty tons, and consumed two hundred kilowatts of power. It generated so much heat that it had to be placed in one of the few rooms at the University with a forced air cooling system. Vacuum tubes, over 19,000 of them, were the principal elements in the computer's circuitry. It also had fifteen hundred relays and hundreds of thousands of resistors, capacitors, and inductors. All of this electronics were held in forty-two panels nine feet tall, two feet wide, and one foot thick. They were arranged in a "U" shape, with three panels on wheels so they could be moved around. An IBM card reader and card punch were used respectively for input and output.

??? So, Which one was really the first Computer ???

As we said earlier, not an easy call. The teams of Atanasoff and Berry (the ABC) and Eckert and Mauchly (ENIAC) claimed to have developed the first computer. Arguments became so heated that the matter was taken to court. On October 19, 1973, US Federal Judge Earl R. Larson signed his decision following a lengthy court trial which declared the ENIAC patent of Mauchly and Eckert invalid and named Atanasoff the inventor of the electronic digital computer -- the Atanasoff-Berry Computer or the ABC.

So, the ABC was the first computer !!!

Legally, yes, but many people still have some problems with the decision:

bulletThe ABC used electromagnetic relays, and was really a prototype
bulletThe Mark I was fully functional, but also relied on electromechanical parts
bulletThe ENIAC was completely electronic

Who cares anymore !!!
At least the first generation of computers began !!!

Not really -- All of these computers were either prototypes or proprietary machines. The first generation of computers does not begin until the computer becomes commercially available.

 ??? When is that ???

1951, but we will discuss that in the next section on the characteristics of 1st generation computers.

This page was last updated on 02/27/07.