History of Computers

 

Abacus 

The first known device capable of making calculations, something so fundamental to the development of today’s computer industry. Greeks and Romans used the abacus in ancient times, and the Chinese made significant improvements.

1642

French mathematician, Blaise Pascal, developed a “gear-driven” mechanical calculator. Capable of addition, subtraction, and multiplication. 

1671

German mathematician, Gottfried Leibnitz, improved upon Pascal’s design. The mechanical calculator could offer both division and the ability to determine square roots.

1812

Charles Babbage, an English mathematician, visualized that many of the principles of Jacquard’s loom and its use of punched cards could be applied to numerical computation. Responsible for the first development of the concept of the “stored program” for data processing which differentiates calculators from computers. Babbage called his first machine a difference engine and designed it to calculate logarithm tables. Many regard Charles Babbage as the first person to propose the concept of the computer.

The major components of Babbage’s analytical engine were as follows:

 • Input and output devices 

 • An arithmetic unit to perform calculations 

 • A memory (punched cards) to store the calculations

Augusta Ada Byron

An accomplished mathematician, she analyzed and improved many of Babbage’s concepts. Has been recognized as the first programmer as a result of her work in developing and programming the mathematical tables for Babbage’s analytical engine. The programming language ADA is named in her honor.

First Generation Computers 1951–1958 

Included the UNIVAC-1; which 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 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. 

The emergence of the microcomputer or PC was a major advancement, especially with user-friendly software and graphic terminals