Alternatively referred to as an electron tube or valve and first developed by John Ambrose Fleming in 1904. The vacuum tube is a glass tube that has its gas removed, creating a vacuum. Vacuum tubes contain electrodes for controlling electron flow and were used in early computers as a switch or an amplifier.
First Generation Of Computers
The period of first generation was from 1946-1959. The computers of first generation used vacuum tubes as the basic components for memory and circuitry for CPU (Central Processing Unit). These tubes, like electric bulbs, produced a lot of heat and the installations used to fuse frequently. Therefore, they were very expensive and only large organizations were able to afford it.
The period of second generation was from 1959-1965. In this generation, transistors were used that were cheaper, consumed less power, more compact in size, more reliable and faster than the first generation machines made of vacuum tubes. In this generation, magnetic cores were used as the primary memory and magnetic tape and magnetic disks as secondary storage devices.
IC- Silicon chips can contain computer processors, memory and special devices. The chip is very fragile and so is normally surrounded by a tough plastic package, and electrical contact with the chip is provided through metal legs sticking out of the package.
The IC was invented by Jack Kilby.
Third generation computers
The period of third generation was from 1965-1971. The computers of third generation used Integrated Circuits (ICs) in place of transistors. A single IC has many transistors, resistors, and capacitors along with the associated circuitry.
Micro processors
A microprocessor is a small computer contained on an integrated circuit, also called a semiconductor chip or microchip. It can function as the “brain” of a personal desktop computer. A computer’s microprocessor performs arithmetic and logic operations, provides temporary memory storage, and times and regulates all elements of the computer system. Microprocessors are used in many other electronic devices, including cell phones, kitchen appliances, automobile emission-control and timing devices, electronic games, telephone switching systems,
Fourth Generation Computers
Fourth generation computers became more powerful, compact, reliable, and affordable. As a result, it gave rise to Personal Computer (PC) revolution. In this generation, time sharing, real time networks, distributed operating system were used.
Fifth Generation Computers
This generation is based on parallel processing hardware and AI (Artificial Intelligence) software. AI is an emerging branch in computer science, which interprets the means and method of making computers think like human beings.
The main features of fifth generation are −
ULSI technology
Development of true artificial intelligence
Development of Natural language processing
Advancement in Parallel Processing
Advancement in Superconductor technology
More user-friendly interfaces with multimedia features
Availability of very powerful and compact computers at cheaper rates
