computer generetion

Computer Generations

Ø First Generation (1964-1954)

·       The first generation computer used vacuum tube as CPU components.

·       First generation computer used machine language & assembly language for programing.

·       There was no concept of operating system at that time.

·       Key boards were used to punch cards & paper tapes. Printers were used to get printed output.

·       Example of first generation computers are :-

                                                            I.            EDVAC(Electronic Discrete Variable Computer,1951)

                                                         II.            UNIVAC(Universal Automatic Computer,1951)

                                                      III.            IBM`s 701(1953)

                                                     IV.            IBM 704 (1955)

                                                        V.            IBM 709

Ø Second Generation (1955-1964)

·       Transistors were used in computers in place of vacuum tubes.

·       Magnetic ferrite-core memory was used as main memory which is a random access non-volatile memory. The memory capacity of the second-generation computers was about 1K bytes.

·       Magnetic disk memory was developed during this period. Magnetic disks and magnetic tapes were used as secondary memory.

·       Machine independent high-level languages like FORTRAN, COBAL and ALGOL were developed and used as programming languages.

·       Hardware for floating point arithmetic operations was developed.

·       Index registers were introduced which increased the flexibility in programming.

·       During this period computers are widely used in industry and commercial organization.

·       Examples of Second-Generation Computers are:--

                                                                                I.            IBM 1620 (1960)

                                                                             II.            IBM 7090 (1960)

                                                                          III.            IBM 7094 (1962)

                                                                         IV.            PDP 5 (1963)

Ø Third Generation (1965-1974)

·       The third generation computer used IC`s (SSI & MSI) in CPU, I/O processors and other electronic components.

·       Magnetic core memory used as main memory, magnetic disk is used as secondary memory & magnetic tapes are used as back up memory. 100M bytes disk drives are available at this time.

·       This generation computer is multi-processor & multi user system.

·       Example of third generation computers are:-

                                                                        I.            IBM/370series

                                                                     II.            CDC 7600 (1969)

Ø Fourth Generation (1975-1990)

·       The fourth generation computers used microprocessor as CPU. Memory, supporting chips, I/O processors, controllers etc. also uses ICs (LSI/VLSI chips).

·       The microprocessor`s chip multifunctional peripheral chips providing functions of interrupt controller, DMA controller, timer/ counters, bus controller, etc. on a single IC were developed.

·       CRT screen, laser printers, inkjet printers, scanners etc were developed.

·       Semiconductor memory chips constituted the main memory of fourth generation computers. Secondary memory was composed of hard disks. Floppy disks and magnetic tapes were used for backup memory.

·       During this period of fourth generation high speed computer network LANs and WANs were developed. The operating system MS-DOS, Apple`s Macintosh with GUI an object oriented language C++, etc were developed.

·       Examples of fourth generation computers are

                                                                                                                                                         I.            Computers based on Intel’s 8088, 80286, 80386 and 80486.

                                                                                                                                                      II.            Motorola`s 6800, 68020, 68030 and 68040 computers.
Ø Fifth generation computer(1991-present)
·       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 computer sat cheaper rates
·       Examples are

   I.        Pentium(1-4)

    II.        AMD athlon