The term “computer generation” means the evolution of the hardware and other components of computer. From past time to present the computers are changing with their sizes, capabilities and many other things. There are mainly 5 generations of computer till now which are given below
1. The First Generation of Computers (1942 – 1955)
The first generation of computers uses vacuum tubes for circuitry and machine language was used for giving instruction in the computer, magnetic drums are used as the storage device and punch card is used for giving input, the computers of this generation were very large in size and their programming was so difficult. In this generation Batch OS (operating system) is used for operating computers with the help of binary language.
Some of the examples of first generation computers are ENIAC, EDSAC, EDVAC, UNIVAC – I, etc.
2. The Second Generation of Computers (1955 – 1964)
In this generation a big revolution in electronics occurs with the invention of “Transistors” by coordination of Bardeen, Brattain and Shockley in 1946, it replaces the whole circuitry from big vacuum tubes to small transistors which are more reliable and faster, so the computers of this generation is much smaller then first generation computers and they also releases very less amount of heat in comparison to vacuum tubes. In this generation Time Sharing OS is used for operating computers with the help of assembly language and other HLL languages like FORTRAN, COBOL, ALGOL, SNOBOL etc.
Some of the examples of second generation computers are IBM 1401, IBM 1620, CDC 1604, etc.
3. The Third Generation of Computers (1964 – 1975)
The third generation of computers replaces transistors with “Integrated Circuits” or I.C.s which was invented by Jack Kilby in 1958, an I.C. have many resisters, capacitors and transistors combined together on a single Silicon plate or chip, this generation uses I.Cs from Small scale integration (SSI) circuits which have about 10 transistors per chip to medium scale integration (MSI) circuits with 100 transistors per chip, also in this generation computers uses Remote Processing, Multiprogramming, Time Sharing etc operating systems in which the languages used like PASCAL, BASIC PASCAL, C etc.
Some of the examples of third generation computers are IBM-360, ICL-2900, ICL-1900 series, etc.
4. The Fourth Generation of Computers (1975 – 1989)
In the fourth generation of computers the advent (coming) of the microprocessors chip give rise to a micro circuitry with medium scale integration (MSI) circuits to very large scale integration (VLSI) circuits packing by about 50000 transistors on a single chip, some of the computers of this generation are portable and available for personal uses, they are also affordable by almost peoples. The storage capacity in these generation computers is higher then before, there is also lead to form various types of networks in between these computers systems in this generation, the operating system used in this generation computers is MS – DOS(Microsoft Disk Operating System), Windows 98, etc and the languages used are like C, C++, APE, SQL, WAVE, etc.
5. The Fifth Generation of Computers (1989 – Present)
The fifth generation computers and other computing devices are based on artificial intelligence and are still in development, they used the features like parallel processing, multi users, multimedia, etc. Superconductors is helping to make artificial intelligence a reality yet, fifth generation computers could also include speech and visual recognition like features and also they are based on (GUI) graphical user interface, these generation computers uses ultra large scale integration and have less power consumption, they are easy to use and provide us a user interface. In this generation the feature of internet is achieved by inter-joining the various networks over world-wide. This generation computers uses languages like OPS5, Lisp, ICAD, etc and operating system uses like Windows 7, Windows 8,Windows 10, etc.