Basic Computation and Programming with C

GENERATIONS OF COMPUTER

The first electronic digital computer, called the Atanasoff–Berry Computer (ABC), was built by Dr John V. Atanasoff and Clifford Berry in 1937. An electronic computer called the Colossus was built in 1943 for the US army. Around the same time, many others were also trying to develop computers. The first general-purpose digital computer, the Electronic Numerical Integrator and Computer (ENIAC), was built in 1946. Computers since 1946 are categorized in five generations:

• • First Generation: Vacuum Tubes

• • Second Generation: Transistors

• • Third Generation: Integrated Circuits

• • Fourth Generation: Microprocessors

• • Fifth Generation: Artificial Intelligence

Follows a brief description of each generation:

First Generation (1946–1956) Vacuum Tubes

Vacuum tubes were used to make circuits of first generation computers. For building memory, magnetic drums were used that were huge in size and weight. First generation computers were so large in size that they often took an entire room. They were also very prone to error. They were too expensive to operate and in addition consumed huge electricity. It is worth mentioning the amount of heat they generated. Despite using liquid based cooling system, they often got damaged due to heat.

Programs for first generation computers were written in machine language, the lowestlevel programming language understood by computers, to perform operations. They were designed to solve only one problem at a time. Punched cards and paper tapes were used to feed input, and output was displayed on printouts.