Generations of computer

·         “Generation”in computer talk is a step in technology.  It provides a framework for the growth of computer industry

·         Originally it was used to distinguish between various hardware technologies, but now it has been extended to include both hardware and software

·         Till today, there are five computer generations

Generation       (Period)	Hardware Technology	Software Technology	Characteristics	Some representative System
First (1942-1955)	Vacuum tubes         Electromagnetic relay memory           Punched cards secondary storage	Machine and assembly languages           Stored program concept          Mostly scientific applications	Bulky in size          Highly unreliable          Limited commercial use and costly          Difficult commercial production          Difficult to use	·        ENIAC ·         EDVAC ·          EDSAC ·         UNIVAC I ·          IBM 701
Second (1955-1964)	Transistors   Magnetic cores memory   Magnetic tapes   Disks for secondary storage	Batch operating system   High-level programming languages   Scientific and commercial applications	Faster, smaller, more reliable and easier to program than previous generation systems   Commercial production was still difficult and costly	Honeywell 400   IBM 7030   CDC 1604  UNIVAC LARC
Third (1964-1975	ICs with SSI and MSI technologies   Larger magnetic cores memory  Larger capacity disks and magnetic tapes secondary storage   Minicomputers; upward compatible family of computers	Timesharing operating system  Standardization of high-level programming languages  Unbundling of software from hardware	Faster, smaller, more reliable, easier and cheaper to produce   Commercially, easier to use, and easier to upgrade than previous generation systems   Scientific, commercial and interactive on- line applications	IBM 360/370   PDP-8   PDP-11   CDC 6600
Fourth (1975-1989)	ICs with VLSI technology  Microprocessors; semiconductor memory   Larger capacity hard disks as in-built secondary storage  Magnetic tapes and floppy disks as portable storage media   Personal computers   Supercomputers based on parallel vector processing and symmetric multiprocessing technologies § Spread of high-speed computer networks	Operating systems for PCs with GUI and multiple windows on a single terminal screen   Multiprocessing OS with  concurrent programming languages   UNIX operating system with C programming language   Object-oriented design and programming   PC, Network-based, and super-computing applications	Small, affordable, reliable, and easy to use PCs   More powerful and reliable mainframe systems and supercomputers   Totally general purpose machines  Easier to produce commercially   Easier to upgrade   Rapid software development possible	IBM PC and its clones   Apple II  TRS-80   VAX 9000   CRAY-1   CRAY-2  CRAY-X/M
Fifth (1989- Present)	ICs with ULSI technology   Larger capacity main memory, hard disks with RAID support   Optical disks as portable read-only storage media   Notebooks, powerful desktop PCs and workstations   Powerful servers,  supercomputers   Internet   Cluster computing	Micro-kernel based, multithreading, distributed OS   Parallel programming libraries like MPI & PVM   JAVA   World Wide Web   Multimedia, Internet applications   More complex supercomputing applications	Portable computers   Powerful, cheaper, reliable, and easier to use desktop machines   Powerful supercomputers   High uptime due to hot-pluggable components  Totally general purpose machines   Easier to produce commercially, easier to upgrade   Rapid software development possible	IBM notebooks   Pentium PCs   SUN Workstations   IBM SP/2   SGI Origin 2000   PARAM 10000

First Generation Computer

Second Generation Computer

Third Generation Computer

Fourth Generation Computer

Five Generation Super computer

Five Generation Robot