Computers as we know them today have become an integral part of our lives and day to day activities. Before we move on to generations and history of computers, we must first understand what a computer is. A computer is an electronic device for storing and processing data, typically in binary form, according to instructions given to it in a program. It could also be defined as an electronic machine that accepts raw data (input), processes the data and produces output in a predefined manner, that is, in a way that the owner wants it. A computer can carry out complex calculations in a matter of seconds and it is always correct as long as the data fed into it is correct.
The word COMPUTER was coined from the Latin word “COMPUTARE” which means to calculate or to count and was first recorded in 1613, to describe someone who carries out calculations. Computers have developed from just a calculating device to a digital and electronic one. Some of the early computers were:
ABACUS: This is known to be the first mechanical calculating device which was used to perform additions and subtractions easily. The device allowed the user to make computations using a system of sliding beads arranged on a track. It was first developed by the Egyptians in the 10th century B.C. but it was given its final shape in the 12th century A.D. by Chinese educationalists.
PASCAL’S CALCULATOR: In 1642, Blaise Pascal the 18-year-old son of a French tax collector, invented this calculator to help his father with his duties and called it A NUMERICAL WHEEL CALCULATOR. It was also called PASCALINE or PASCAL CALCULATOR.
ANALYTICAL ENGINE: The real beginnings of computers as we know them today however lay with an English mathematics professor named Charles Babbage. He invented a machine to prevent errors during calculations which was called the DIFFERENCE ENGINE. He soon realized that a more general design was possible: The design of the analytical engine started in 1833.
HOLLERITH MACHINE: In 1889 an American inventor Herman Hollerith invented an electro-mechanical machine designed to assist with the computing of the U.S. census. It used punched cards to store information. He also established the Tabulating Machine Company in 1896 which later became International Business Machines (IBM) in 1942.
ENIAC: ELECTRONIC NUMERIC INTEGRATOR AND COMPUTER was the world’s first successful electronic computer which was developed by two scientists J.P. Eckert and J.W. Mauchy. It used the concept of vacuum tubes.
Generations of Computers
First Generation: Vacuum Tubes (1940-1956)
The first computer systems used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. These computers were very expensive to operate. In addition to using a great deal of electricity, they generated a lot of heat, which was often the cause of malfunctions.
First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. It would take operators days or even weeks to set up a new problem. Input was based on punched cards and paper tape, and output was displayed on printouts.
The UNIVAC and ENIAC computers are examples of first generation computing devices. The UNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951.
Second Generation: Transistors (1956-1963)
The world has seen transistors replace vacuum tubes in the second generation of computers. The transistor was invented at Bell Labs in 1947 but did not see widespread use in computers until the late 1950s.
The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damages, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.
Third Generation: Integrated Circuits (1964-1971)
The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips called semi-conductors which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.
Fourth Generation: Microprocessors (1971-Present)
The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the hand. The Intel 4004 chip, developed in 1971, located all the components of the computer from the central processing unit and memory to input/output controls on a single chip.
In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.
As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of graphic user interfaces (GUIs), the mouse and handheld devices.
Fifth Generation: Artificial Intelligence (Present and Beyond)
Fifth generation computing devices are based on artificial intelligence and are still in development though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality.
Quantum computation, molecular and nano-technology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.
Sources:
1) Webopedia.com.
2) Introduction to Computers by Dr. Jerry Sarumi