THE GENERATIONS OF COMPUTERS

Computers are such an integral part of our everyday life now most people take them and what they have added to life totally for granted. first-generation-computerEven more so the generation who have grown from infancy within the global desktop and laptop revolution since the 1980s. The history of the computer goes back several decades however and there are five definable generations of computers. Each generation is defined by a significant technological development that changes fundamentally how computers operate – leading to more compact, less expensive, but more powerful, efficient and robust machines.

? First Generation Computers, 1951–1958

Included the UNIVAC-1;

Used vacuum tubes for controlling functions;

Used magnetic drums for primary storage;

First generation software used symbolic language for programming; and

Machine language programs were used by the binary forms of zeroes and ones.

? Second Generation Computers, 1959–1964

The transistor replaced the vacuum tube and made possible the second generation of computers; Magnetic tape was introduced and replaced the need for punched cards; and COBOL and FORTRAN programming languages were introduced.

? Third Generation Computers, 1965–1971

Integrated circuits made possible the third generation of computers as incredible numbers of transistors were deposited on a silicon chip, thus introducing the era of  miniaturization and increased speed.

The nanosecond (one billionth of a second) became the new standard for measuring access and process time.

IBM’s System/360 computers and the first minicomputer by Digital Equipment Corporation were introduced.

Online computers and remote terminals became popular using regular telephone lines from remote locations.

Business applications increased, especially in the airline reservation systems and real-time inventory control systems.

? Fourth Generation Computers, 1971–1990

The introduction of large-scale integrated (LSI) circuits for both memory and logic made the IBM 370 mainframe possible by LSI circuits. The movement to the very-LSI circuits made it possible to place a complete central processing unit (CPU) on one very small semiconductor chip.

This resulted in increased computer performance with a phenomenal lowering of the cost of computers. The processing power of mainframe computers in the 1960s costing millions of dollars was now available for use in personal computers (PCs) for less than $1000.

Historical Reference Points in the Computer Industry The emergence of the microcomputer or PC was a major advancement, especially with user-friendly software and graphic terminals.

? Fifth Generation The period of fifth generation: 1980-onwards. ULSI microprocessor based.