Fundamental of Computer

Introduction to computer

       We live in computer age. Most o four day-to day activities is being influenced by the use of computers. While in areas like science and technology improvements cannot be achieved without computers, it has

become necessary for each and every one of us to have a basic knowledge of computer.

What is computer?

       On simple words, a computer is an electronic device which processes information based upon the instructions provided, and generates the desired output. Like any other system, a computer system also requires an input which processed to get the desired output, in the case of computer; two kinds of inputs are required. One, the basic or raw data, and two a set of instructions containing the methodology top process this data. This set of instruction is called program or software in computer speak. This can be schematically illustrated as in Fig,

 

    

 Some people erroneously believe that computers can only work on arithmetic operations, or a good background in mathematics is a pre-requisite for learning computers. Nothing could be further from truth. Although it is correct that the computer internally processes all information’s mathematically, the user can work on any kind of data text, numeric, alpha-numeric, images, pictures, sound, video clipping, etc. in fact, most of the computer applications nowadays are non-numeric.

 

Full forms of computer

C                     command

O                     operate

M                     machine

P                      particularly

U                     used for

T                      tread

E                      education

R                      research

What’s so special about computers?

    The five characteristics of computers which have made then so powerful and useful are:

• Speed
• Accuracy
• Consistency
• Storage capacity
• Flexibility

Speed: - computers work at an incredible speed. This can be gauged from the fact that the speed of the computers is measured in terms of milliseconds, microseconds, nanoseconds or picoseconds, i.e. one thousandth, one millionth, one billionth, and one trillionth of a second, respectively. Chances are there that the computer you are presently working on, would be processing information at the speed of a couple of a million instructions per second, also called MIPS in computer jargon.

Accuracy: in addition to being fast, computers are also accurate. They either give the correct answer or do not answer at all. However, it must be remembered that the computer is capable doing only what it is instructed to do. If faulty instructions are provided for processing the data, obviously faulty answers will be given. This is also called GIGO, i.e. Garbage Out. Hence, the only possibility of an error occurring is due to inaccurate instructions or faulty data.

Consistency: unlike human being, computers being machines are highly consistent. They never get bored too! I am yet to meet a computer complaining of a monotonous job! Hence, they are ideal machines for carrying out repetitive and voluminous work.  

 Storage capacity: - today’s computers can store huge amounts of data. Once recorded, a piece of information is never forgotten (unless some problem takes place) and any information can be retrieved almost instantaneously. To give you an idea of storage capacity.

Flexibility:- a computer us a versatile machine and its use is limited only by your imagination. In today’s fast developing technology- work it would be very different, in some cases inconceivable, to find an area where computers are not being used to a great advantage. However, computers have one major limitation, computers are not originally creative, and would never be. They would never be able to write an old man and the sea, they would never be able to paint a monalisa (although they can faultlessly duplicate it), and they would never be able to compose beethoven’s sonata. And thank God for it!  

History of computers

Evolution

   In order to understand today’s computers, it might be worthwhile to take a quick look at the evolution of computers. Historians start the history of calculation with the Abacus (a wooden frame with balls or beads strung on parallel wires) and trace its origin to around 5000 B.C. it was used for performing simple calculations. In the seventeenth century, john napier, a Scottish mathematician, did considerable work on the aids for calculation. The most notable one was the invention of logarithms in 1614.

     In 1620, just six years after the invention of logarithms, William oughtred, an English mathematician, invented the slide rule. This is a calculating device based on the principles of logarithms. A slide rule consists of two graduated scales, one of which slides over the other. The scales are devised in such a manner that suitable alignment of one scale against the other makes it possible to compute products, additions, etc., just by inspection. In 1642, Blaise pascal, a French mathematician, invented the first mechanical calculating machine. In this machine, numbers were entered by dialing a series of numbered wheels. Another series of tooted wheels transferred the movements to a dial, which showed the results. Gottfried von Leibnitz, a German mathematician, in 1671 invented a calculating machine which was able to perform multiplications and divisions. between 1802 and 1804, joseph Marie jacquard, a French textile manufacturer, invented a mechanical system foe use in the textile industry. This machine was used to automatically control weaving looms to facilitate the production of woven cloth with complex patterns.

    In 1822, Charles Babbage, a professor of mathematics at Cambridge university, devised a machine called “difference engine” for the royal society. This difference engine was used to perform simple computations needed for setting up trigonometric and logarithmic tables. In short, Babbage had developed a prototype computer which was 100 years ahead of its time. He is, therefore, widely considered as the father of modern day computers.

Generation of the computer

First generation(1940-1959):- In this generation of the computer, vacuum tubes were used as parts. These were very big, with less storage capacity and got over heated. Their speed of operation was vary slow of its examples are given below:

(i). Electronic numeric integrator and calculator(ENIAC)

      this contained 18,100 vacuum tubes, 70,100 resistors, 10,100 capacitors and 60,100 switches. This could do 5000 additions per seconds. Too cool it, it needed a water cooler and it power consumption was 150k watts.

(ii). Electronic delay and automatic storage computer(EDASC).

(iii). Electronic descreet variable automatic computer(EDVAC)

(iv). BM-701 and IBM-650

Second generation (1959-1964):- In these types of computers instead of vacuum tubes, transistor were used, As a result of which its size and cost etc. were reduced. Second generation computers had a better growth in comparison to first generation computers and also the power consumption was reduced. Following are the computers of the second generation:

(i). IBM-700

(ii). ATLAS

(iii). IBM-1401

Third generation (1964-1970):- In these types of computer integrated circuits were used. These were called chips. These mainframe computers that come in this generation are:

(i)                  IBM-360 seres.

(ii)                ICL-1900 series.

(iii)               IBM-370 series.

Fourth generation (1971-1990):- In these types of computer chips component were used. Microprocessor were used.

Fifth Generation(1990-till date):- These generation of computer have been produced in large numbers. Various types of large scale integrated circuits (VLSI) and microprocessor chips were used. These Computer are small in size, low in cost and are of high speed.

        In these microprocessor computers, IC’s chip made of silicon if used on fabricated surfaces. The computer on which these chips were used are called microprocessor computers. Some models of these types are given below:

(i). apple macintosh

(ii). IBM- ps/2

(iii). DEC alpha

Sixth generation:- Such computer are being made that cover whole world and these will be available in the market soon.

Comparison between the generations of computer

1st Generation computer	2nd Generation computer	3rd Generation computer	4th Generation computer
§         Use of vacuum tubes §         Limited storage capacity §         Sloe speed §         Symbolic language programming huge size §         Problems of over heating	§         Use of transistors and diodes §         Increased storage capacity §         Faster speed §         Reduction in size and heat  generation	§         Use of integrated circuits §         More flexibility with input/output §         Smaller size and better performance §         Remote processing and time sharing	§         Use of large scale and very large scale §         Increase storage §         Considerably faster and smaller §         Modular design versatility and compatibility §         Increased use of microcomputers(PCs)

       As you go through the history of evolution of computer you would find that the earliest computers were very big and because they were very big, they consumed a lot of power and, because they consumed a lot of power, they heated up tremendously and, because they heated up very quickly, they had to be frequently shut down and cooled; because of all this they were very expensive to build and maintain. As the technology improved, computers become smaller and smaller. They also become much faster and more powerful. But most importantly, form user’s point of view, they become more affordable and used-friendly. And that has been the real success of computer and that’s why they have been able to transform themselves from ‘huge monoliths’ to ‘personal assistants’ it is just a matter of time when they enter the next phase of their evolution and become ‘domestic appliances’ as simply to operate as a refrigerator, as useful as a microwave oven and as common as T.V.

Basic Anatomy of computers

THE BASIC COMPONENTS

   As explained earlier, any computer essentially has three important parts, namely, input device, central processing devices and output device. The central processing unit (CPU) itself has three parts, namely memory unit, control unit and arithmetic and logical unit. These three units along with the input and output devices form the five important components of any computer system...

Functioning of the computer

   The input devices are used to transfer the information into the memory unit of a computer. Information from the memory can be transferred to the ALU where comparisons or calculations are done and the result are sent back to the memory unit. Thus, the memory unit is used to store the set of instruction that determines the operations to be carried out on a set of data as well as the data on which these operations are performed. The memory unit is also called the main memory or the immediate access store (IAS). The coordination and control of the operations of a computer system is the sole responsibility of the control unit. It accepts instructions held in store, interprets this instruction and process them for execution by appropriate parts of the system in the correct sequence. The control unit ensures that, according to the stored instruction, the right operation is done on the right data at the right time. The result that is stored in the memory can be transformed into a form that can be understood by us by means of an output device

Memory

    The computer’s memory is a scratch pad where information, which includes both programs and data, is kept while it is being worked on. A computer’s memory consists of a large number of storage spaces known as cells or locations, which are organized into units of bytes, each comprising 8 bits. No matter what kind of information is being stored, it is coded in some particular form of bits, which is interpreted in a way that is appropriate to the kind of data. The same memory bytes are used to record program instruction codes, numeric or alphabetic data. Consider the following:-

  8bit                                                                                      1Byte

1024Byte                                                                               1KB

1024KB                                                                                1MB

1024MB                                                                                1GB

1024GB                                                                                 1TB

1024TB                                                                                 1PB

             

         KB                                                                               Kilo byte

         MB                                                                               Mega byte

         GB                                                                                Giga byte

         TB                                                                                Tear byte

          PB                                                                               Pita byte

The compulsory component of the computer

1. Motherboard: it is the main board of the computer which operates all the functions of the computer. Microprocessor is also fitted on this motherboard. all the utility cards in a computer as well as hard disc, floppy disc, keyboard, mouse, printer, scanner etc. all add on cards and devices are physically connected to it. It depends on the microprocessor of the computer that which motherboard is most compatible for its use. First of all when we have to determine that which microprocessor based computer we have to assemble.

2. Monitor: monitor is also known as a display unit. It is a unit that works independently and is used to display the work being done by the computer. These monitors are also of two types black& white and color monitor. The second basis of comparison is the resolution. Here resolution means clarity of picture. The third basis of difference in the monitor is its size. At present mono monitor is not much in demand. In present 15" and d 17" monitors are most popular. As the difference of cost between 15"and 17" monitors is very less.

3. Processor: it is the mind of the computer. Its operation the all data and instructions. It has mainly three parts.

1. A.L.U. (arithmetical logical unit):- this is part of central processing unit. It perform all electronic mathematical calculations of the computer. It also performs all arithmetical tasks of additions, subtractions, multiplications, divisions and all logical tasks.

2. M.U. (memory unit):- its job is to collect all information and being utilize while working on the computer. So that it can be used again in future as and when needed. In the memory there is a specific location for each and every bit of information, which can be accessed by the ALU when required.

3. C.U. (control unit):- this is a part of the CPU and is the main part of the computer. Its job is to control the input and output of information. For example if a computer has to perform two different jobs at the same time than it has to follow instructions of these separate jobs. This department of the CPU performs this job.

4. Keyboard: It is most commonly used input device. It can be used with any computer. These days many types of keyboards are available but there is not more difference between then. A computer keyboard is similar to the typewriter keyboard. But a computer keyboard has some extra keys. The difference between various types of keyboards available in the market is mainly due to the number of the keys in each one of them. Mainly keyboard are of two types AT and PS2.In the present market a keyboard with 121 keys is most popular because a computer without multimedia is not available I the market today. For such multimedia function some additional keys are provided on this Keyboard.

5. Hard Disk: this is the compulsory part of the computer. It is a permanent storage device. It is mainly of three types on the basis for this purpose. Winchester, IDE and SCSI. In earlier times Winchester disc drives were used which were of 20, 40, 80,129 MB. Along with this a controller card known as WDC card was used, after this IDE drives came into use and are being used currently also. These are available in the storage capacity of 40, 80, 120 GB. Wherever the data is to be written or read at a high speed as in servers, hard disc of SCSI type are used. A controller card is attached to these SCSI hard discs where extra RAM is used to transfer data. Today the most popular brand is Seagate IDE hard disc.

6. Ram: RAM is that portion of a computer where all the programs and data related to computer is sent to CPU. This RAM also affects the speed of the computer because every time the CPU takes data from this RAM only. This RAM stores information and data as long as the computer is on, but as coon as the computer is switched off this data is erased.

7. Cables: cables are used to join the computer parts each other. Different types of cables are required to join them. Like as

Power cable

Monitor cable

Hard disk cable

Floppy disk cable etc.

8. Mouse: - since the popularity of windows in the market, it has become impossible to work on a computer without a mouse. Mouse is a pointing device, which is mainly used for software with graphical user interface. The most popular operating system of today that is windows is also with a graphical user interface. When we use its other associate programs such as EXPLORER etc for internet purposes then it is impossible to select and use a single button without a mouse. In the market today two types of mouse are available. One mouse is with wire, and the second one is wireless mouse. On the basis of technique mouse is of two types- Ball mouse and optical mouse. Today an optical mouse with ps2 connector is the most prevalent mouse in the market.

8. S.M.P.S. (switch mode power supply):- This is installed in the CPU of the computer. This provides power supply to various parts of the computer namely motherboard, hard disk, and floppy disk etc. its output is in form of different volts, which are used for different purpose mainly SMPS is of two types AT and ATX. The basis of the other different is its watts. In present times AT power supply is obsolete in the market while use of ATX power supply is prevalent.

9. Cabinet: - It’s that part of the computer which is identified as CPU in its physical form. It is made up of iron and plastic. In this Mother Board, SMPS, Floppy drive, hard disc drive and CD drive etc are installed. While purchasing it we must keep in mind its size and looks mainly. In the market today, different types of cabinet front panels made of galvanized sheets are available

The Optional part of the computer

1. Compact Disk (CD) Rom: in present times as the utility of the computer is increasing so the size of the data and software to be stored is also increasing. Since the storage size of the floppy is small so in its place CD is used for storage. These CD Drives are available in market with different speeds. At present the CD ROM Drive of 52x speed is more popular.
 2. UPS (Uninterrupted power supply): Its main function is to provide power to save the work done in a computer, during the power failure. Today the most popular for this purpose is 500va off line UPS. Mainly UPS is of two types off line and on line. Wherever there is critical power consumption we use on line UPS. It depends upon the battery used in the UPS as to how much backup it will provide in the event of a power failure A UPS with a 500va is appropriate to operate a computer.

3. Joystick: - It is a pointing device used normally to play games on the computer. In many games as compared to the mouse and keyboard, it provides more reliable control. It is connected to the game port of the computer.

4. PRINTER: - It is a detachable device. Its main function is to print the information obtained from the computer on a paper. On the basis of the quality the printers are mainly of three types Dot Matrix, Inkjet and Laser. The most popular print currently is Inkjet. These printers are also based on various Brand and DPI.

5. Pen Drive

Classification of computers

The computer we can classification in three types.

Analog computer: this type of computer is used for one type of work only. For example- a voltmeter. Analog computer calculates only the input. When it is given a mathematical work and it gives the final result in the form of the output, however the result are not as per the desired answers. The results are in a different form, which can be in the form of a graph also. After seeing this graph we can read the value.

Digital computer:- In this computer counting/ calculations of the numeric data is done. In digital computer different departments do different type of work. For example, if addition work is to be done then the digital calculation is controlled by the mathematical department. The digital computer has been designed to solve static and numeric problems.

Hybrid computer:- In this type of computer- analog and digital, both type of technique is used. This computer is used to convert analog information to digital information and from digital information to analog information.

Types of computer in size 

1. mainframe computer
2. mini computer
3. micro computer
4. supper computer

Software components

         The hardware alone cannot perform any particular calculation or manipulation without being instructed exactly what to do and how to do it. These set of instructions are as important if not more than the hardware, and are called software. The software acts as an interface between the user and the computer. Software or a program can be defined as a complete set of instructions written by the programmer which enables the computer to obtain the solution to a problem (with or without the data). The software used by a computer may be classified into applications software, systems software and utility software.

The application software: - These are programs employed by the user to perform specific functions. For example, application software can be program used for accounting control in business or a program used for engineering design.

The system software: - They consist of all the programs, languages, and documentation supplied by the manufacturer with the computer. These programs allow the user to communicate with the computer and write or develop his own programs. This software makes the machine easier to use and makes an efficient use of the resources of the hardware possible. Systems software is programs held permanently on a machine, which relieve the programmer from mundane tasks and improve resource utilization. MS-DOS or Microsoft Disk Operating system is one such, and one of the most widely used systems software for IBM compatible microcomputers.

The utility software: - these may be considered as a border line case between applications software and system software. This software is either used as specific tools while developing a program or package, or to perform a limited specific task, such as scanning the hard disk for viruses.

Computer is an electronic machine/device which is used to data processing. There are three steps on computer:

Input                                        Process                                    Output 

Input: input is an instruction which is given to the computer by the user.

Process: process is the operation of the input.

Output: output if the result of operation.

Input unit: An input unit involves the devices through which raw data or instructions are entered the computer. The main work of input unit is enter the input to the computer. Like as keyboard, mouse etc.

Processing unit: processing unit is used to process the data. Like as processor/CPU/microprocessor. we have been already discussed about the processor.

Output unit: these are used to display the result like as monitor.

Monitor: monitor is also known as a display unit. It is a unit that works independently and is used to display the work being done by the computer. These monitors are also of two types black& white and color monitor. The second basis of comparison is the resolution. Here resolution means clarity of picture. The third basis of difference in the monitor is its size. At present mono monitor is not much in demand. In present 15" and d 17" monitors are most popular. As the difference of cost between 15"and 17" monitors is very less.

Windows XP

  Windows is an operating system. It is a master controller program. It is an improved version of windows 89, ME and replacement of disk operating system. Operating system is a program which controls overall operations of the computer. It is the media between the computer and operator. It is developed by Microsoft company in U.S.A. it is a multitasking operating system which provides graphical user interface to the user.

Operating system:

An operating system is a master control program that runs the computer and acts as scheduler. It controls the flow of signals from CPU to various parts of the computer. It is the first program loaded into the computer’s memory after the computer is switched on. Popular operating system include MS-DOS, windows and unix. The operating system is an important component of the computer system because it sets the standards for the application programs must be written to “take to” the operating system.

Wallpaper: It is the background of desktop. We can change and make our own wallpaper.

Desktop:     It is the first screen of windows operating system.

Icons:         Icons are the pictures arrange shortcuts.

Folder:        Folder is the collection of files.  We can save our files in folder.

Shortcut:     Shortcuts are used to open programs by just clicking once.

Start button:

      It is the especial button, which is used to start the program based on the windows. It enable you to access. When you click the start cotton, you will see a menu, which contains everything you need to being using windows.

Turn off computer: It enable you to shutdown, restart and stand by the computer.

Log off:- It is used to switch between one user to another user.

Run:        It is used to run the program.

Search:   It help to find/search an object and its location. It saves your time .we can search the files and folder over the computer.

Setting:   setting is used to make the accessories setting in the computer. it display the list of system components, which lets you to change the configuration as your requirement.

Documents: It display a list of files, which are recently create and opened. You can easily open this item without opening its associated program.

Program:   it display a list of program’s name and program groups that can be directly used.

How to find files on our computer.

1. Click at start button.
2. Click search option.
3. Go to for files and folder option and click on it.
4. Click your own desire, what do you want to search.
5. If you want to search the files and folder click on the files and folder option and  type the name of the files and folder in the name box, what do you want to search.
6. Choose the location in “look in” box, where you want to search and click search.

Default icons of the desktop

 1. My Computer:- This contain all the drives. We can open drives.

Like as; C, D, E, CD ROM, etc.

2. My Documents:- This icons is the default store place to store our files. Computer automatically save our files in my document.

3.  Internet Explore:- It is a icons, which is used to open the web side while using internet.

4. Network Place:- Network place is used to networking. We can  open network connection.

5. Recycle Bin: This option is used to store the deleted files and folder of our computer. We can restore our deleted files when required.

How to create new folder?

1. Right click on the desktop, A pop-up menu will be appear on the screen, choose the new option.
2. Choose the folder option and click on it.
3. A new folder will be appear on the screen, we can give the name of our new folder.
4. Click on the blank area of the desktop.

How to create shortcut

1. Right click on the desktop and choose the new option.
2. Go to shortcut option and click on it.
3. A box appear on the screen, click on the browse.
4. Click at program for which you want to create shortcut.
5. Click ok then next.
6. Write the name of the shortcut in the name box then click finish

Taskbar properties:

 1. Click the right mouse button anywhere inside the Taskbar.

2. Click on properties.

(i). Lock the Taskbar:

  it locks the taskbar then you cannot move and resizeit.

(ii). Auto hide the taskbar:

         it behaves as a toggle in nature. If you move the mouse pointer over the taskbar then it shows otherwise hides.

(iii). Always on top:

         it keeps the taskbar on the top of other opened windows. If you remove the tick mark from this option, then you can not see the taskbar, if other windows are opened.

(iv). Group similar taskbar button:

         this option is used to group list of more than four same files or folders. We can easily reopen files or folder and we can also close the same files or folders in group list. If you want to remove this option it takes in individual files and folders on the taskbar.

(v). show quick lunch:

     it display some important icons like desktop, internet explorer, windows media player etc. which can be directly launched(open).

(vi). Hide inactive icons:

    it hides some inactive icons like LAN, Messenger, Anti-virus, Volume, Intel graphics etc. on the taskbar.

Arranging Desktop:

This option is used to arrange the icons in the desktop.

(i). Minimize button:

         This button is used to minimize the opened window in the taskbar. But we can reopen on later by click on it the taskbar without starting its associated program.

(ii). Maximize button:

         This option is used to display the window in full screen of that all items can seen.

(iii). Restore button:

       We can also resize or restore this maximize window to its previous size again by using this button, we can manage all opened window in full screen in tile form with the help of this button.

(iv). Close button:

       This button is used to close any opened window as our requirement.