Technology History and the Development of Computers AOIT Principles of Information Technology

The word computer has a broad meaning What is a computer? A computer is a person, instrument, or machine that gathers, processes, and stores information.

Early counting methods were very basic The first counting tools were people’s own fingers. The word digit can refer to a finger (or toe) or to a single character in a number system. Bones with carved notches have been found in Europe dated between 30,000 to 20,000 B.C. One had notches in groups of five — early evidence of the tally system. When you use objects instead of fingers to count, you can store results for later reference.

Charles Babbage is called the “father of computing” Charles Babbage designed a steam- powered calculator called the Difference Engine in His next idea was the Analytical Engine (1856), designed to perform any kind of mathematical calculation.

The British Colossus decoded messages during WWII In 1943, the British built the first “Colossus” computer. These machines were used to decipher encrypted teleprinter messages sent by the Germans during World War II.

Integrated circuits brought “chips” to computers One major step in computer development was the integrated circuit, a group of tiny transistors and electric wires built on a silicon wafer, or “chip.” Over the years, integrated circuits have continued to get smaller in size but larger in their capacity to function.

The Altair was a computer individuals could afford The first computer that most individuals could afford was the Altair 8800, built in 1975 by a small company, MITS. Since there was no keyboard or screen, information was entered by clicking switches on the front of the machine.

Apple created the first user-friendly personal computer Steve Jobs and Steve Wozniak created the first user-friendly personal computer, called the Apple, with a built-in keyboard, display screen, and storage unit. The term personal computer refers to a computer designed to be used by one person at a time.

The IBM PC gave way to many clone “compatibles” In 1981, IBM introduced its version of the personal computer—the IBM PC. IBM made the general design available to competing companies, resulting in many clones or “compatibles.” Today, the term PC often refers to computers running Microsoft’s Windows operating system.

Personal computers are also called microcomputers Microcomputers are more commonly known as personal computers. Microcomputers come in many different shapes and sizes. The microcomputers shown at the right are “desktop” models, which are generally meant to stay in one place.

Laptops and PDAs are also microcomputers Notebook or laptop computers are portable microcomputers. An even smaller portable microcomputer is a “handheld” device, often referred to as a personal digital assistant (PDA).

Workstations are more powerful than microcomputers Workstations are single-user computers that are more powerful than microcomputers. Workstations are commonly used by professionals such as engineers, scientists, and graphic artists.

Minicomputers & mainframes process and store lots of data Minicomputers and mainframe computers are generally connected to many other computers, or terminals. A minicomputer is smaller and less powerful than a mainframe. Government agencies and businesses that need to process and store lots of information use these.

Supercomputers are the most powerful computers Supercomputers are the largest, most powerful, and most expensive computers. Supercomputers are not very common.

Image credits The images on slide 7, the telegraph on slide 10, the images on slide 14, the Macintosh on slide 16, and the PC on slide 17 can be accessed on wikipedia.org and are reproduced here under the terms of the GNU Free Documentation License. Permission is granted to copy, distribute, and/or modify these images under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is available at The image on slide 8 can be accessed on wikipedia.org and is reproduced here under the terms of the Creative Commons Attribution ShareAlike 1.0 license. The original photograph was taken by Joe D. in January The image on slide 11 can be accessed on It shows the Hollerith Electric Tabulator at the US Census Bureau, Washington, DC, 1908, Photograph by Waldon Fawcett. Library of Congress, LC-USZ It The Sun workstation on slide 20 can be accessed on All other images are in the public domain.