IT Future's World

The History of Computers

2009-12-27T06:08:00.000-08:00

"Who invented the computer?" is not a question with a simple answer. The real answer is that many inventors contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention.
This series covers many of the major milestones in computer history (but not all of them) with a concentration on the history of personal home computers.

Computer History Year/Enter	Computer History Inventors/Inventions	Computer History Description of Event
1936	Konrad Zuse - Z1 Computer	First freely programmable computer.
1942	John Atanasoff & Clifford Berry ABC Computer	Who was first in the computing biz is not always as easy as ABC.

Inventors of the Modern Computer

2009-12-27T05:58:00.000-08:00

The Atanasoff-Berry Computer the First Electronic Computer - John Atanasoff and Clifford Berry

John Atanasoff
Clifford Berry

Inventors of the Modern Computer Series

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John Atanasoff
Clifford Berry on the Web

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Biographical information on the inventors, pictures and technical drawings of the Atanasoff-Berry Computer, the patent dispute, court papers and transcripts.

By Mary Bellis "I have always taken the position that there is enough credit for everyone in the invention and development of the electronic computer" - John Atanasoff to reporters.
Professor John Atanasoff and graduate student Clifford Berry built the world's first electronic-digital computer at Iowa State University between 1939 and 1942. The Atanasoff-Berry Computer represented several innovations in computing, including a binary system of arithmetic, parallel processing, regenerative memory, and a separation of memory and computing functions.
Presper Eckert and John Mauchly were the first to patent a digital computing device, the ENIAC computer. A patent infringement case (Sperry Rand Vs. Honeywell, 1973) voided the ENIAC patent as a derivative of John Atanasoff's invention. Atanasoff was quite generous in stating, "there is enough credit for everyone in the invention and development of the electronic computer." Eckert and Mauchly received most of the credit for inventing the first electronic-digital computer. Historians now say that the Atanasoff-Berry computer was the first.

"It was at an evening of scotch and 100 mph car rides," John Atanasoff told reporters, "when the concept came, for an electronically operated machine, that would use base-two (binary) numbers instead of the traditional base-10 numbers, condensers for memory, and a regenerative process to preclude loss of memory from electrical failure."
John Atanasoff wrote most of the concepts of the first modern computer on the back of a cocktail napkin. He was very fond of fast cars and scotch.
Atanasoff-Berry Computer
In late 1939, John Atanasoff teamed up with Clifford Berry to build a prototype. They created the first computing machine to use electricity, vacuum tubes, binary numbers and capacitors. The capacitors were in a rotating drum that held the electrical charge for the memory. The brilliant and inventive Berry, with his background in electronics and mechanical construction skills, was the ideal partner for Atanasoff. The prototype won the team a grant of $850 to build a full-scale model. They spent the next two years further improving the Atanasoff-Berry Computer. The final product was the size of a desk, weighed 700 pounds, had over 300 vacuum tubes, and contained a mile of wire. It could calculate about one operation every 15 seconds, today a computer can calculate 150 billion operations in 15 seconds. Too large to go anywhere, it remained in the basement of the physics department. The war effort prevented John Atanasoff from finishing the patent process and doing any further work on the computer. When they needed storage space in the physics building, they dismantled the Atanasoff-Berry Computer.

Inventors of the Modern Computer

2009-12-27T05:55:00.000-08:00

The First Freely Programmable Computer invented by Konrad Zuse

Konrad Zuse

Inventors of the Modern Computer Series

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Konrad Zuse on the Web

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Konrad Zuse biography and technical details on his computers.

By Mary Bellis Konrad Zuse (1910-1995) was a construction engineer for the Henschel Aircraft Company in Berlin, Germany at the beginning of WWII. Konrad Zuse earned the semiofficial title of "inventor of the modern computer" for his series of automatic calculators, which he invented to help him with his lengthy engineering calculations. Zuse has modestly dismissed the title while praising many of the inventions of his contemporaries and successors as being equally if not more important than his own.
One of the most difficult aspects of doing a large calculation with either a slide rule or a mechanical adding machine is keeping track of all intermediate results and using them, in their proper place, in later steps of the calculation. Konrad Zuse wanted to overcome that difficulty. He realized that an automatic-calculator device would require three basic elements: a control, a memory, and a calculator for the arithmetic.

Konrad Zuse's Z1 Circa 1938

In 1936, Zuse made a mechanical calculator called the Z1, the first binary computer. Zuse used it to explore several groundbreaking technologies in calculator development: floating-point arithmetic, high-capacity memory and modules or relays operating on the yes/no principle. Zuse's ideas, not fully implemented in the Z1, succeeded more with each Z prototype.
In 1939, Zuse completed the Z2, the first fully functioning electro-mechanical computer.
Konrad Zuse completed the Z3 in 1941, with recycled materials donated by fellow university staff and students. This was the world's first electronic, fully programmable digital computer based on a binary floating-point number and switching system. Zuse used old movie film to store his programs and data for the Z3, instead of using paper tape or punched cards. Paper was in short supply in Germany during the war.
According to "The Life and Work of Konrad Zuse" (by Horst Zuse)

In 1941, the Z3 contained almost all of the features of a modern computer as defined by John von Neumann and his colleagues in 1946. The only exception was the ability to store the program in the memory together with the data. Konrad Zuse did not implement this feature in the Z3, because his 64-word memory was too small to support this mode of operation. Due to the fact that he wanted to calculate thousands of instructions in a meaningful order, he only used the memory to store values or numbers. The block structure of the Z3 is very similar to a modern computer. The Z3 consisted of separate units, such as a punch tape reader, control unit, floating-point arithmetic unit, and input/output devices.

Konrad Zuse wrote the first algorithmic programming language called 'Plankalkül' in 1946, which he used to program his computers. He wrote the world's first chess-playing program using Plankalkül.

The Plankalkül language included arrays and records and used a style of assignment (storing the value of an expression in a variable) in which the new value appears in the right column. An array is a collection of identically typed data items distinguished by their indices (or "subscripts"), for example written something like A[i,j,k], where A is the array name and i, j and k are the indices. Arrays are best when accessed in an unpredictable order. This is in contrast to lists, which are best when accessed sequentially.

Zuse was unable to convince the Nazi government to support his work for a computer based on electronic valves. The Germans thought they were close to winning the War and felt no need to support further research.
The Z1 through Z3 models were destroyed during the war along with Zuse Apparatebau, the first computer company that Zuse formed in 1940. Zuse left for Zurich to finish his work on the Z4, smuggling the Z4 from Germany in a military truck, which he hid in stables on route to Zurich, Switzerland. He completed and installed the Z4 in the Applied Mathematics Division of Zurich's Federal Polytechnical Institute, in use there until 1955. The Z4 had a mechanical memory with a capacity of 1,024 words and several card readers. Zuse no longer had to use movie film to store programs; he could now use punched cards. The Z4 had punches and various facilities to enable flexible programming including address translation and conditional branching. In 1949, he moved back to Germany to form a second company called Zuse KG for the construction and marketing of his designs. Zuse later rebuilt models of the Z3 in 1960 and the Z1 in 1984.

computer

2009-12-26T22:23:00.001-08:00

A programmable machine. The two principal characteristics of a computer are:

It responds to a specific set of instructions in a well-defined manner.

It can execute a prerecorded list of instructions (a program).

Modern computers are electronic and digital. The actual machinery -- wires, transistors, and circuits -- is called hardware; the instructions and data are called software.
All general-purpose computers require the following hardware components:

memory : Enables a computer to store, at least temporarily, data and programs.

mass storage device : Allows a computer to permanently retain large amounts of data. Common mass storage devices include disk drives and tape drives.

input device : Usually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.

output device : A display screen, printer, or other device that lets you see what the computer has accomplished.

central processing unit (CPU): The heart of the computer, this is the component that actually executes instructions.

In addition to these components, many others make it possible for the basic components to work together efficiently. For example, every computer requires a bus that transmits data from one part of the computer to another.
Computers can be generally classified by size and power as follows, though there is considerable overlap:

personal computer : A small, single-user computer based on a microprocessor. In addition to the microprocessor, a personal computer has a keyboard for entering data, a monitor for displaying information, and a storage device for saving data.

workstation : A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and a higher-quality monitor.

minicomputer : A multi-user computer capable of supporting from 10 to hundreds of users simultaneously.

mainframe : A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.

supercomputer : An extremely fast computer that can perform hundreds of millions of instructions per second.