Detailed Introduction To Computer

This generation use computer on daily basis. So, I thought of giving detailed introduction to computers.

The word computer comes from a word "Compute" which means to calculate.Hence,a computer is normally considered to be a calculating device,which that can perform arithmetic operations at enormous speed.In fact the original objective for inventing the computer was to create a fast calculating machine.However,more over 80 % of the work done by computers today is of non-mathematical or non-numerical nature.Hence,To define a computer merely as a calculating device is to ignore over 80% of its function.
More accurately a computer may be defined as a device,which operates upon data.Data can be anything like bio data of various applicants when the computer is used for recruiting personnel,or the marks obtained by various student's in various subjects when the computer is used to prepare result or the detail ( name,age,sex) of various passengers when the computer is employed of making airline of railway reservations,or number of different types in case of use of computers for solving scientific research problems etc.

 Hence data comes in various shapes and sizes,depending upon the types of computer application.A computer can store,process and retrieve data as and what desired.The fact that computer process data is so fundamental that many people have started calling it a data processor.

The name data processor is more inclusive because modern computers not only compute in usual sense,but also perform other functions with the data,which flow to and from them.For example,data processors may gather data from various incoming sources,merge (process of mixing or putting together) them all,sort (process of arranging in some sequence-ascending or descending) them in the desired folder.and finally print the in the desired format.None of these operations involve the arithmetic operations normally associated with the computing device,but the term computer is often applied anyway.

The activity o processing data using a computer is called data processing.Data processing consists of there sub-activities capturing the input data,manipulating the data, and managing the output results.As used in data processing,information is data arranged in an order and form,which is useful to the people who receive it.
Hence,data is the raw material used as input to data processing and information is the processed data obtained as the output of data processing.

Characteristics Of Computer:

The increasing popularity of computer has proved that it is very powerful and useful tool.The power and usefulness of this popular tool are mainly due to it's following properties:

1-Automatic:

A machine is said to be automatic.If it works itself without human intervention.Computers are automate machines because once started on job.they carry on,until the job is finished,normally without any human assistance.However,computer being machines cannot start themselves.They can not go out and find their own problems and solutions.They have to be instructed.That is,a computer works from a program of coded instructions.which specify exactly how a particular job is to be done.Some of the other characteristics of computers,such as speed and accuracy,are due to fact that they are automatic and work on a problem without any human intervention.

2-Speed:

A computer is very fast device.It can perform in few seconds,the amount of work,that a human being can do in an entire year-if he work day and night and did not nothing else.To put it in a different manner a computer does in one minute what would take a man his entire lifetime.

       While talking about the speed of computer,we do no talk in terms of seconds or even milliseconds.Our units of speed are the microseconds,the nanoseconds and even the picoseconds.A powerful computer is capable of performing several billion simple arithmetic operations per second.

3-Accuracy:

In addition being very fast,computers are very accurate.The accuracy of computer is consistently high, and the degree of accuracy of a particular computer depends upon its design.However or a particular computer every calculation is performed with the same accuracy.

Errors can occur in computer.However,these are mainly due to human rather than technological weakness.For example,errors may occur due to imprecise thinking by the programmer (a person who writes instructions for a computer to solve a particular problem) or incorrect input data.Computers errors caused due to incorrect input data or unreliable programs are often referred to as garbage-in-garbage-out(GIGO)

4-Diligence:

Unlike,human beings a computer is free from monotony,tiredness and lack of concentration.It can continuously work for hours,without creating any error and without grumbling.Hence,computers score over human beings in doing routine type of jobs,which require great accuracy.If ten million calculations have to be performed,a computer will perform the ten millionth calculation with exactly the same accuracy and speed as the first one.

5-Versatility:

Versatility is one of the most wonderful thing about computer.One moment it is preparing the results of the examination,the next moment,it is busy preparing electricity bills,and in between,it may be helping an office secretary to trace an important letter in seconds.All that is required to change its talent is to slip in new program (a sequence of instructions for the computer) into it.Briefly a computer is capable of performing almost any task,if the task can be reduced to a series of logical steps.

6-Power of Remembering:

As a human being acquires new knowledge,the brain subconsciously select what it feels to be important worth retaining in its memory and relegates unimportant details to the back of the mind or just forgets them.This is not the case with computers.A computer can sore or recall any amount of information because its secondary storage (a type of detachable memory)Every piece of information can be retained as desired by the user and can be recalled,as and when required.Even after several years,the information recalled would be as accurate as on the day when it was fed to the computer.A computer forgets or looses certain information only when it is asked to do so.Hence, it is entirely up to to the user to take a computer retain or forget a particular information.

7-NO I.Q:

A computer is not a magical device.It possesses no intelligence of its own.Its I.Q is zero at least until today.It has to be told what to do and in what sequence.Hence only the user can determine what tasks a computer will perform.A computer cannot take its own decision in this regard.

8-No Feeling:

Computers are devoid of emotions.They have no feeling and no instincts,because they are machines.Although men have succeeded in building a memory for the computer,but no knowledge and experience we often make certain judgements in our day-to-day-life.However,computers cannot make such judgements on their own.Their judgement is based on the instructions given to them in the form of programs that are written by us.

The Evolutions Of Computer:

Necessity is the mother of invention.The saying holds true for computers also,because computers were invented because of man's search for fast and accurate calculating device.

The first mechanical adding matching was invented by Blaise Pascal in 1642.Later in the year 1671, Baron Gottfried Wilhelm von Leibniz of Germany invented the first calculator for multiplication.Keyboard machines originated in the united States around 1880 and are extensively used even today.Around the period only,Herman Hollerith came up with the concept of punched cards,which were extensively used as input medium in computers even in late 1970s.Business machines and calculators made their appearance in Europe and America towards the end of the nineteenth century.

Charles Babbage,a nineteenth century Professor at Cambridge University,is considered the father of modern digital computers.During his period,mathematical and statistical tables were prepared by a group of clerks.Even the utmost care and precautions could not eliminate human errors.Babbage had to spend several hours checking these tables.Soon he became dissatisfied and exasperated with this type of monotonous job.The result was that he started thinking to build a machine,which could computer tables guaranteed to be error-free.In this process,Babbage designed a "Different Engine"in the year 1822 which could produce reliable tables.In 1842,Babbage came out with his new idea of Analytical Engine,which could produce reliable tables.In 1842, Babbage came out with his new idea of Analytical Engine,which was intended to be completely automatic.It was to be capable of performing the basic arithmetic functions for any mathematical problem and it was to do so at an average speed of 60 additions per minute.Unfortunately,he was unable to produce a working model of this machine,because the precision engineering required to manufacture the machine was not available during that period.However,his efforts established a number of principles,which have been shown to be fundamental to the design of any digital computer.In order to have a better idea of the evolution of computers,let us now briefly discuss about some of the well-known early computers.These are as follows:

1-The Mark 1 Computer (1937-44):

Also known as Automatic Sequence Controlled calculator,this was the first fully automatic calculating machine designed by Howard A. Aiken of Harvard University in collaboration with IBM (International Business Machines)Corporation.Its design was based on the techniques already developed for punched card machinery.It was an electromechanical device,since both mechanical and electronic components were used in its design.

Although machine proved to be extremely reliable.It was very complex in design and huge in size.It used over 3000 electrically actuated switches to control its operations and was approximately 5- Feet long and 8 Feet high.It was capable of performing five basics arithmetic operations :addition,subtraction,multiplication,division and table reference.A number.A number as big as 23 decimal digits could be used in this machine.It took approximately 0.3 second to add two numbers and 4,5 seconds for multiplication of two numbers.Hence,the machine was very slow as compared today's computers.

2-The Atanasoff-Berry Computer (1939-42):

The electronic machine was developed  by Dr.John Atanasoft to solve certain mathematical equations.It was called the Atanasoff-Berry Computer or ABC,after the inventor's name and his assistant,Clifford Berry.It used 45 Vacuum tubes for internal logic and capacitor for storage.

3-The ENIAC (1943-46):

The electronic Numerical integrator and calculator was the first all electronic computer.It was constructed at the Moore School of Engineering of the University if Pennsylvania U.S.A by a design team led by Professors J.Presper Eckert and John Mauchly.

ENIAC was developed because of military need,and was used for many years to solve ballistic problems.It too up the wall space in 20 x 40  square feet room and used 18,000 vacuum tubes.The addition of two numbers was achieved in 200 microseconds and multiplication in 2000 microseconds 4-The EDVAC(1946-52):
A major drawback of ENIAC was that it programs were wired on boards,which made it difficult o change the programs.this problem was later overcome by the "store program"concept introduced by Dr.John Von Neumann.The basic idea behind this concept is that a sequence of instructions,as well as the data,can be stored in the memory of the computer ,from automatically directing  the flow of operations.This feature considerably influenced the development of modern digital computers because of the ease with which different programs can be loaded and executed on the same computer.Due to this feature we often refer to modern digital computers as stored program digital computers.The Electronic Discrete Variable Automatic Computer (EDVAC) was designed on stored program concept.Von Neumann also has a share of the credit for introducing the idea of storing both instructions and data in the binary form (a system that uses only two digits 0 and 1 to represent all characters)instead of the decimal numbers or human readable words.

4-The EDSAC (1947-49):

Almost simultaneously with EDVAC of U.S.A,the Britishers developed the electronic Delay Storage Automatic Calender (EDSAC).The machine executed its program in May 1949.In this machine,addition operation was accomplished in 1500 microseconds and multiplication operation in 4000 microseconds.The machine was developed by a group of scientists headed by Professor Maurice Wikes at the Cambridge University Mathematical Laboratory.

5-The UNIVAC 1 (1951):

The universal Automatic Computer (UNIVAC)was the first digital computer was,which was not "one of a kind".Man UNIVAC machines were produced,the first of which was installed in the Census Bureau in 1951 and was used continuously for 10 years.The first business use of a computer,a UNIVACI was by General Electric Corporation in 1954.
                                               In 1952,the International Business Machines (IBM) Corporation introduced the 701 commercial computer.In rapid succession,improved models of the UNIVAC 1 and other 700 series machines were introduced.In 1953,IBM produced the IBM-650 and sold over 1000 of these computers.
The commercially available digital computers,which could be used for business and scientific applications had arrived.

This is by far easiest intro to computers. If you have any questions, let us know in comments.

Have a good day.

Detailed Five Generations Of Computer ( 1st to 5th)

Generation in a computer is a step in technology.It provides a framework for the growth of the computer industry.Originally, the term "generation" was used to distinguish between varying hardware technologies.However,nowadays it has been extended to include both hardware and software,which together make up an entire computer system.
The custom of referring to the computer era in terms of generations into wide use only after 1964.There are totally five computer generations known until today.Each generation has been discussed below in detail along with its identifying characteristics.Although there is a certain amount of overlapping between generations the approximate dates shown against each normally accepted.

During the description of the various computer generations,you will come across several terminologies and computer jargon's,which you might not be aware of,and may not be able to understand properly.However,the idea here is to just give you an overview and technologies will be described an detail in subsequent chapters.Moreover,remember that the objective of this book is also the same-to introduce you to the various concepts about computers.Hence,you will have a better understanding of the terminologies introduced in this section only after you have completed reading this entire book.The objective of this section is mainly to provide an overview of what all you are going to learn in this entire book.

First Generation of Computer (1942-1955):

We have already discussed about some of the early computer-ENIAC,EDVAC,EDSAC,UNIVAC 1 and IBM 701.These machines and others of their time were built by using thousands of vacuum tubes.A vacuum tube was a fragile glass device,which used filaments as a source of electronics and could control and amplify electronic signals.It was the only high-speed electronic switching device available in those days.These vacuum tube computers could perform computations in milliseconds and were referred to as first generation computers.

The memory of these computers was constructed using electromagnetic,relays and all data and instructions were fed into the system from punched cards.The instructions were written in machine and assembly languages because high-level programming languages were introduced much later.Because machine and assembly languages are very difficult to work with,only a few specialists understood how to program these early computers.
The characteristic features of first-generation computer are as follows:
1-They were fastest calculating devices of their time.
2-They were too bulky in size,requiring large rooms for installation.
3-Thousands of vacuum tubes,which were used emitted large amount of head and burnt out frequently.Hence,the room/areas in which these computers were located had to be properly air-conditioned.
4-Each vacuum tube consumed about half a watt of power.Since a computer typically used more than ten thousand vacuum tubes,the power of these computers was very high.
5-As vacuum tubes used filaments,they had a limited life.Since thousands of vacuum tubes were used in making one computer,these computers were prone to frequent hardware failures.
6-Due to low mean time between failures,these computers required almost constant maintenance.
7-In these computers,thousands of individual components had to be assembled manually by hand into functioning circuits.Hence,commercial production of these computers was difficult and costly.
8-Since these computers were difficult to program and use they had limited commercial use.

Second Generation of Computer (1955-1964):

1-A new electronic switching device called transistor was invented at Bell Laboratories in 1947 by John Bardeen,William Shockley and Walter Brattain.Transistors proved to be a better electronic switching device than the vacuum tubes due to their following properties:

1-They were more rugged and easier to handle than tubes since they were made of germanium semiconductor material rather than a glass.
2-They were highly reliable as compared to tubes since they had no part like filament,which could burn out.
3-They could switch much faster (almost ten times faster) tubes.Hence,switching circuits made of transistors could operate much faster than the computer parts made of tubes.
4-They consumed almost one-tenth the power consumed by a tube.
5-They were much smaller than a tube.
6-They were less expensive to produce.
7-They dissipated much less heat as compared to vacuum tubes.
The second-generation computer were manufactured using transistors,instead of vacuum tubes.Due to the properties of transistors listed above the second generation computers were more powerful,more reliable, less expensive,smaller and cooler to operate than the first-generation computers.

The memory of the second-generation computers was composed of magnetic cores.Magnetic disk and magnetic tape were the main secondary storage media used in second-generation computers.Punched cards were still popular and widely used for preparing programs and data to be fed to these computers.

On the software font,the second generation saw the emergence of high-level programming languages and batch operating systems.High-level programming languages like FORTAN,COBOL,ALGOL and SNOBOL were developed during the second generation period which were much easier for people to understand and work with than assembly or machine languages.Hence the second generation computers were easier to program and use than first generation computers.The introduction of batch operating system allowed multiple jobs to be batched together and submitted at a time and automatic transition from one job to another,as soon as the former job finished.This concept in reducing human intervention while processing multiple jobs,resulting in faster processing enhanced throughout and easier operation of second generation computers.

The first generation computers were mainly used for scientific computations.However,in the second generation in increasing usage of computers was seen in business and industry for commercial data processing applications like payroll,inventory control,marketing and production planning.

The characteristic features of second generation computers are as follows:
1-They were more than ten times faster than the first generation computers.
2-They were much smaller than first generation computers requiring small space.
3-Although the heat dissipation was much less than first generation computers,the rooms/areas in which the second generation computers were had to be properly air-conditioned.
4-They consumed much less power than the first generation computers.
5-They were more reliable and less prone to hardware failures than the first generation computers.
6-They had faster and larger primary and secondary storage as compared to first generation computers.
7-They were much easier to program and use than the first generation computers.Hence,they had wider commercial use.
8-In these computers,thousands of individual transistors had to be assembled manually by hand into functioning circuits.Hence,commercial production of these computers was difficult and costly.

Third Generation of Computer:

In 1958,Jack St.Clair Kilby and Robert Noyce invented the first integrated circuit. Integrated circuits (called IC's) are circuits consisting of several electronic components like transistors,resistors and capacitors grown on a single chip of silicon eliminating wired interconnection between components.The IC technology was also known as "microelectronics" technology because it possible integrate larger number of circuit components into very small (less than 5mm square) surface of silicon,known as "chip".Initially the integrated circuits contained only about ten to twenty components.This technology was named small scale integration (SSI).Later,with the advancement in technology for manufacturing IC's,it became possible to integrate up to about hundred components on a single chip.This technology came to be known as medium scale integration (MSI).The third generation was characterised by computers built using integrated circuits.The earlier ones used SSI technology and the later ones used MSI technology. IC's were much smaller,less expensive to produce,more rugged and reliable,faster in operation,dissipated less heat and consumed much less power than circuits built by wiring electronic components manually.Hence,third generation computers were more powerful,more reliable,less expensive,smaller and cooler to operate than the second-generation computers.

Parallel advancements in storage technologies allowed to construction of large magnetic cores based random access memory,and large capacity magnetic disks and magnetic tapes.Hence,the third generation computers typically had few megabytes (less than 5 megabytes) of main memory and magnetic disks capable of storing few tens of megabytes of data per disk drive.

On the software front,the third generation saw the emergence of standardisation of high-level programming languages,time sharing operating systems unbending of software from hardware and the creations of an independent software industry FORTAN COBOL,which were the most popular high-level programming languages in these days,were standardised by the American National Standars Institure (ANSI) in 1966 and 1968 respectively.They were referred to as ANSI,FORTAN and ANSI COBOL.The idea was that as long as computer with an ANSI,FORTAN or ANSI COBOL compiler.Additionally,some more high-level programming languages were introduced during the third-generation period.Notable among these PLAI,PASCAL and Basic.

We saw that in second-generation computer batch operating system was used.In these systems,users had to prepare their data and programs ad then submit them to the computer centre for processing.The operator at the computer centre collected these user jobs and fed them to the computer in batches at scheduled intervals.The output produced for each job was then sent to the computer centre counter for bring returned to some users especially programmers,because often they had to wait for days to locate and correct a few program errors.To remedy this situation,John Kemeny and Thomas Kurtz of Dartmouth College introduced the concept of time sharing operating system.

Time sharing operating system simultaneously allows a large number of users to directly access and share the computing resources in a manner that each user gets the illusion that no one else is using the computer.This is accomplished by having a large number of independent,relatively low-speed terminals simultaneously connected to the main computer.The introduction of time sharing concept helped in drastically improving productivity of programmers and made on-line system feasible,resulting in new on-line application like airline reservation systems,interactive query systems etc.

Until 1965,computer manufactures sold their hardware along with all associated software,and did not charge separately for the software they provided to customers.For example buyer's received language translators for all the language,which could run on the computers they purchased.From the user's standpoint,all this software was free.However,the situation changed in 1969,when IBM and other computer manufactures began to price their hardware and software products separately.This unbundling of software from hardware gave users as opportunity to invest only in software of their need and value.For example,now buyer's could purchase only the language translators they need and not all the language translators on the computer they purchased.This led to the creation of many new software houses,and the beginning of an independent software industry.
The development and introduction of minicomputers,also took place during he third-generation period.The computers built until the early 1960's were mainframe
systems,which only very large companies could afford to purchase and use.

Clearly,a need existed for low-cost smaller computers to fill the gaps left by the bigger,faster and costlier mainframe systems.Several innovators recognised this need and framed new firms in 1960's to produce smaller computers.The first commercially available minicomputer,the PDP-8 (Programmed Data Processor) was introduced in 1965 by Digital Equipment Corporation (DEC).It could easily fit in the corner of a room and did not require the attention of a full-time computer operator.It was based on time sharing operating system and could be accessed simultaneously by a number of users from different locations in the same building.It cost was about one-fourth of the cost of a traditional mainframe system,making it possible for smaller companies to afford computers.It confirmed the tremendous demand for small computers for business and scientific applications and by 1971,there were more than 25 computer manufactures who had entered the minicomputer market.

The characteristic features of third-generation computer are as follows:
1-They were much more powerful than the second-generation computers.They were capable of performing about 1 million instructions per second.
2-They were much smaller than second-generation computer requiring smaller space.
3-Although the heat dissipation was much less than second-generation computers,the rooms/areas in which the third-generation computers were located had to be properly air-conditioned.
4-They consumed much less power than the second-generation computers.
5-They were more reliable and less prone to hardware failures than the second-generation computers.Hence,the maintenance cost was much low.
6-They had faster and larger primary and secondary storage as compared to second-generation computers.
7-They were totally general-purpose machines suitable for both scientific and commercial applications.
8-Their manufacturing did not require manual assembly of individual components and electronic circuits resulting in reduced labor and cost involved at assembly stage.Hence,commercial production of these systems was easier and cheaper.However,highly sophisticated technology and expensive setup was required for the manufacture of IC Chips.
9-Standardisation of high-level programming languages usage and simultaneous use of these systems by a large number of users.
10-Time sharing operating system allowed interactive usage and simultaneous use of these systems by a large number of users.
11-Time sharing operating system helped in drastically improving the productivity of programmers,cutting down the time and cost of program development by several fold.
12-Time sharing operating system also made on-line systems feasible,resulting in the usage of these systems for new on-line applications.
13-Unbundling of software from hardware gave users of these systems an opportunity to invest only in software of their need and value.
14-The minicomputers of the third-generation made computers affordable even by smaller companies.

Fourth Generation of Computer(1975-1989):

The average number of electronic components packed on a silicon chip doubled each year after 1965.This progress soon led to era of large scale integration (LSI) when it was possible to integrate over 30,000 electronic components on a single chip,followed by very large integration (VLSI) when it was possible to integrate about one million electronic components on a single chip.This progress led to perform dramatic development - the creation of a microprocessor.A microprocessor contains all the circuits needed to perform arithmetic logic and control functions.the core activities of all computers,on a single chip.

Hence,it became possible to build a complete computer with a microprocessor,a few additional primary storage chips and other support circuitry.It started a new social revolution-the personal computer (PC)revolution.Overnight,computers became incredibly compact.They became inexpensive to make, and suddenly it became possible for anyone to own a computer.

During the fourth generation magnetic core memories were replaced by semiconductor memories,resulting in large random access memories with very fast access time.On the other hand,hard disks became cheaper,smaller and larger in capacity.Parallely,in addition to magnetic tapes,floppy disks became popular as a portable medium for porting programs and data from one computer system to another.

Another significant development during the fourth generation period was the spread of high-speed computer networking,which enabled multiple computers to be connected together to enable them to communicate and share data.Local areas networks (LANs) became popular for connecting several dozen or even several hundred computers within an organization or within an campus and wide area networks (WAN's) became popular for connecting computers located at larger distances.This gave rise to network of computers and distributed systems.

Ont the software front,there were several new developments which engaged which emerged to match the new technologies of the fourth generation.For example,several new operating systems were developed for PCs.Notable among these were MS-DS,MS Windows and Apple's propriety OS.Because the PCs were to be used by individuals who were not computer professionals to make computers more user friendly (easier to use) companies developed graphical user interface.A graphical user interface (GUI) Provides icons (pictures) and menus (list of choices)which based applications were more developed to make PCs a powerful tool.Notable among these were powerful word processing packages,which allowed easy development of documents,spreadsheet package which allowed easy manipulation and analysis of data organised in columns and rows and graphic packages.which allowed easy drawing of pictures and diagrams.Another very useful concept,which became popular during the fourth generation period was that of multiple windows on a single terminal screen.

This feature allowed users to simultaneously see the current status of several applications in separate windows on the same terminal screen.During the fourth generation period the UNIX operating system and the C programming language also became very popular
The characteristic features of the fourth-generation computer are as follows:

1-The PCs were smaller and cheaper than mainframes and minicomputers of the third generation.
2-The mainframes were much powerful than the third-generation systems.
3-Although the mainframes required proper air-conditioning of the room ares in which they were located,no air-conditioned was required for PCs.
4-They consumed much less power than third-generation computers.
5-They were more feature and less prone to hardware failures than the third-generation computers.Hence,the maintenance cost was negligible.
6-They had faster and larger primary and secondary storage as compared to third-generation computers.
7-They were totally general purpose machines.
8-Their manufacturing did not require manually of individual components into electronic circuits,resulting in reduced human labour and cost involved at Assembly stage.Hence,commercial production of these systems was easier and cheaper.However,highly sophisticated technology and expensive setup was required for the manufacture of LSI and VLSI chips.
9-Use of standart high-level programming languages allowed programs written for one computer to be easily ported to and executed on another computer.
10-Graphical User Interface (GUI) enabled new users to quickly learn how to use computers.
11-PC based applications made the PCs powerful tool for both office and home page.
12-Network of computers enabled sharing of resources like disks,printers etc among multiple computers and their users.They also enabled several new types o applications involving interaction among computers users of geographically distant locations.Computer Supported Cooperate Working (CSCW) or groupware is one such application,in which multiple members working on a single project and located at distant locations.Cooperate with each other by using a network of computers.
13-In addition to unbundled software,these systems also used add-on hardware feature,which allowed users o invest only in the hardware configuration and software of their need and value.
14-The PCs of the fourth-generation made computers affordable even by individuals for their personal use at home.

Fifth Generation of Computer(1989-Present):

The trend of further miniaturisation of electronic components,the dramatic increase in the power of microprocessor chips and capacity of main memory and hard disk continued in the fifth generation.The VLSI technology became ULSI (Ultra Large Scale Integration) technology in the fifth generation resulting in the production of microprocessor chips having ten million electronic components.In Fact,the speed of microprocessor and the size of main memory and hard disk doubled almost every eighteen months.As a result,many of the features found in the CPU's of large mainframe systems of the third and fourth generations became part of the microprocessor architecture in the fifth generation.This ultimately resulted in the availability of very powerful and compact computers becoming available at cheaper rates and the death of traditional large mainframe systems.

Due to this fast pace of advancement in computer technology we see more compact and more powerful computers being introduced almost every year at more or less the same price or even cheaper.Notable among these are portable computers,which give the power of a PC to their users even while travelling powerful desktop PCs and workstation,powerful servers and very powerful supercomputers.

Storage technology also advanced very fast making larger and larger main memory and disk storage available in newly introduced systems.During the fifth generation,optical disks also emerged as a popular portable mass storage media.They are more commonly known as CD-ROM (Compact Disk-Read Only Memory) because they are mainly used for storing programs and data which are only read (not written modified).

During the fifth generation period,there was tremendous outgrowth of computer networks.Communication technologies became faster day-by-day. and more computers were networked together.This trend resulted in the emergence and popularity of the Internet and associated technologies and applications.The Internet made it possible for computer users sitting across the globe to communicate with each other within minutes by the use of electronic mail (known as e-mail) facility.A vast ocean of information became readily available to the computer users through the World Wide Web (known as WWW).Moreover,several new types of exciting applications like electronic commerce,virtual libraries,virtual classrooms,distance education etc emerged during this period.

The tremendous processing power and the massive storage capacity of the fifth generation computers also made them a very useful and popular tool for a wide range of multimedia applications which deal with information containing text,graphics,animation,audio and video data.In general the data size for multimedia information is much large than textual information because representation of graphics,animation,audio or video media. in digital form requires much larger number of bits than that required for representation of textual information.

The characteristic features of fifth-generation computers are as follows:
1-Portable PCs (called notebook computers) are much more smaller and handy than the PCs of the fourth generation allowing users to use computing facility even while travelling.
2-The desktop PCs and workstations are several times more powerful than the PCs of the fourth generation
3-The mainframes are several times more powerful than the mainframe systems of the fourth generation.
4-Although the mainframes require proper air-conditioning of the rooms/areas in which they are located,no air-conditioning is normally required for the notebook computers,desktop PCs and workstations.
5-They consume much less power than their predecessors.
6-They are more reliable and less prone to hardware failures than their predecessors.Hence,the maintenance cost is negligible.
7-Many of the large scale systems of fifth generation have hot plug gable feature.This feature enables a failed component to be replaces with a new one,without the need to shutdown the system,allowing the up time of the system to be very high.
8-They have faster and larger primary and secondary storage as compared to their predecessors.
9-They are totally general purpose machines.
10-Their manufacturing does not require manual assembly of individual components into electronic circuits,resulting in reduced human labour and cost involved at assembly stage.Hence,commercial production of these systems is easier and cheaper.However,highly sophisticated technology and expensive setup (affordable only by a few organisations in the world) is required for the manufacture of ULSI Chips.
11-Use of standard high-level programming languages allows programs written for one computer to be easily ported and executed on another computer.
12-More user-friendly interfaces with multimedia features make the systems easier to learn and use by anyone including small children.
13-Never and more powerful applications including multimedia applications make the systems more useful in every occupation.
14-The explosion in the size of the Internet,occupied with Internet-based tools and applications have made these systems influence the life of even common men and women.
15-These systems also use the concept of unbundled software and add-on hardware allowing the users invest only in the hardware configuration and software of their need and value.
16-With so many types of computers in all price ranges,today we have a computer for almost any Tye user,whether the user is a small child or a scientist of world-fame.


We have looked at the history of computing divided into 1st to 5th generation of computer, and we have seen how quickly things have changed in the last few decades.However,the rate of technological progress in this area is not slowing down at all.As we enter into 21 century,future generations of computers will evolve with higher capability and user friendliness.In fact,the fastest growth period in the history of computing may be still ahead.