Napier’s Bones in an Abacus invented by John Napier.Napier’s used the bone rods for counting purpose where numbers were printed on them. With the help of these rods ,one could do addition, subtraction, multiplication and division speediy.
Pascal’s calculator called ‘Pascaline’ In the year 1642, Blaise Pascal a French scientist invented an adding machine called Pascal’s calculator, which represents the position of digit with the help of gears in it. Though these machines were early forerunners to computer engineering, the calculator failed to be a great commercial success.
Leibniz was successfully introduced as a calculator onto the market in the year 1646. It was designed further in 1673 but it took until 1694 to complete. The calculator could perform the basic mathematical operations such as add, subtract, multiply, and divide. Wheels were placed at right angles which could be displaced by a special stepping mechanism.
This analytical engine, the first fully- automatic calculating machine, was constructed by British computing pioneer Charles Babbage (1791-1871), who first conceived the idea of an advanced calculating machine to calculate and print mathematical tables in 1812. This Analytical Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general- purpose computer that could be described in modern terms as Turing -complete.
The beginning of commercial computer age is from UNIVAC (Universal Automatic Computer). The first generation computers were used during 1942-1955. They were based on vacuum tubes. Examples of first generation computers are ENIVAC and UNIVAC-1.
- • Vacuum tubes were the only electronic component available during those days.
- • Vacuum tube technology made possible to make electronic digital computers.
- • These computers could calculate data in millisecond.
- • The computers were very large in size.
- • They consumed a large amount of energy.
- • Non-portable.
- • Limited commercial use.
- • Very slow speed.
- • Used machine language only.
- • Used magnetic drums which provide very less data storage.
Second Generation Computers (1955-1964)
The second generation computers used transistors. The size of the computers was decreased by replacing vacuum tubes with transistors. The examples of second generation computers are IBM7094 series, IBM1400 seriesand CDC164 etc.
- • Smaller in size as compared to the first generation computers.
- • Used less energy and were not heated.
- • Better speed and could calculate data in microseconds
- • Used faster peripherals like tape drives, magnetic disks, printer etc.
- • Used Assembly language instead of Machine language.
- • Cooling system was required
- • Constant maintenance was required
- • Only used for specific purposes
- • Costly and not versatile
Third Generation Computers (1964-1975)
The Third generation computers used the integrated circuits (IC). The first IC was invented and used in 1961. The size of an IC is about ¼ square inch. A single IC chip may contain thousands of transistors. The computer became smaller in size, faster, more reliable and less expensive. The examples of third generation computers are IBM370, IBM System/ 360, UNIVAC1108 and UNIVACAC9000 etc. An integrated circuit(IC), sometimes called a chip or microchip, is a semiconductor wafer on which thousands or millions of tiny resistors, capacitors, and transistors are fabricated.
- • Smaller in size as compared to previous generations.
- • More reliable.
- • Used less energy.
- • Better speed and could calculate data in nanoseconds. Disadvantages :
- • Air conditioning was required.
- • Highly sophisticated technology required for the manufacturing of IC chips.
Fourth Generation Computers (1975-Present)
The fourth generation computers started with the invention of Microprocessor. The Microprocessor contains thousands of ICs. The LSI (Large Scale Integration) circuit and VLSI (Very Large Scale Integration) circuit was designed. It greatly reduced the size of computer. The size of modern Microprocessors is usually one square inch. It can contain millions of electronic circuits. The examples of fourth generation computers are Apple Macintosh & IBM PC.
- • More powerful and reliable than previous generations.
- • Small in size
- • Fast processing power with less power consumption
- • Fan for heat discharging and thus to keep cold.
- • Cheapest among all generations
- • All types of High level languages can be used in this type of computers
- • The latest technology is required for manufacturing of Microprocessors.
Fifth Generation Computers (Present & Beyond)
Scientists are working hard on the 5th generation computers with quite a few breakthroughs. It is based on the technique of Artificial Intelligence (AI). Computers can understand spoken words & imitate human reasoning. IBM Watson computer is one example that outsmarts Harvard University Students.