Introduction

Introduction to computer Computer is an electronic device which is used for data processing jobs... CHARLES BABBAGE is called as the father of the computer. It was introduced in the year 1942 Characteristics of computer 1. Speed A computer can perform any jobs very fast. 2. Storage Capacity A computer can store any amount of information in its memory 3. Accuracy It can perform any calculation very accurately. 4. Diligence It can work continuously for 24 hours. I won’t get tired. 5. Versatility It can perform number of operations simultaneously. 6. No IQ It possesses no intelligence at its own. 7. No feelings. Computers have no feelings because it is a machine. Difference between calculator and computer Calculator Computer 1. It works with numeric datas it works with alphanumeric datas. 2. It works manually. It works on the basis of programming. . Program It is nothing but a set of instructions given by a user, Generation of computer 1. First generation (1942 - 1955) It is called as vacuum tube computer Eg: ENIAC, EDVAC, EDSAC Drawbacks 1. Large size 2. Trouble shooting is difficult. 2. Second Generation (1955 - 1964) In this generation computers are manufactured using transistor 3. Third Generation (1964 - 1975) The third generation was based on IC technology. IC - Integrated chip or Silicon chip Firstly two types of chips are manufactured. They are SSI chips - Small Scale Integration chips (it integrates only 10, 20, components) MSI chips - Medium scale Integration chips (It integrates 100,200 ... components) 4. Fourth Generation (1975 onwards) The fourth generation uses the same IC chip. But the power of the IC has been increased. They have invented the LSI chips LSI chips - Large scale Integration chips (It integrates more number of components.) 5. Fifth Generation (Artificial Intelligence) In this generation we use VLSI technology. VLSI chips - Very Large scale Integration chips Basic Computer Operation 1. Input unit 2. Central Processing Unit

3. Output Unit From INPUT UNIT User (Programs and Data)

OUTPUT UNIT

MEMORY

(To user) Output CONTROL UNIT

ARITHMETIC LOGIC UNIT

1. Input Unit 1. It reads the given instructions 2. Then it converts it into binary code 3. It sends the binary code to the CPU for further processing 2. CPU - brain of the computer Control Unit and ALU are together called as CPU 1. Control Unit - It controls the whole computer. 2. ALU - Arithmetic and Logic Unit It performs all arithmetical and logical operations 3. Memory Unit - used for permanent storage. 4. Registers - used for temporary storage 3. Output Unit 1. It reads the binary code 2. Converts it into high level language 3. Displays the result on the monitor Computer Devices Input devices 1. Keyboard It is just like a typewriter with some additional keys. It is used to type the text 2. Mouse It is a three button device which is used in the windows environment. 3. Light pen It is purely used for graphical purpose and cad drawings. 4. Optical Mark Reader (OMR) It is used in the examination centers for tutor marked answers. 5. Magnetic Ink Character Recognition (MICR) Used in bank DD and cheque 6. Bar coder In this method, small bars of varying thickness and spacing are printed on packages, books, badges, tags etc which are read by optical readers and converted into electrical pulses. 7. Scanner Used to scan photos and pictures 8. Web camera Used to take photos with high quality Output Devices 1. Monitor or screen or visual display unit An instance display unit which is used to see the result. 2. Printer

Used to prepare permanent document in human readable form (hardcopy). Types of printer 1. Impact printer Impact printer are those while taking print out, the printer head will touch the paper. Eg: 1. Dot matrix printer 2. Line printer 3. Character printer 4. Daisy wheel printer 2. Non Impact Printer Non Impact Printer is those while taking print out the printer head will not touch the paper. Eg: 1. Inkjet printer 2. Laser printer Unit of computer The unit of computer is byte. Byte is nothing but the amount of storage that a storage device can hold. 8 bit = 1 byte 1024 bytes = 1 kilo byte 1024 KB = 1 mega bytes 1024 mb = 1 giga byte Storage Devices Primary storage device RAM (64MB, 128MB, 256MB, 512MB)

Secondary storage devices

ROM Floppy Disk (1.44MB) Hard Disk (20, 40,80GB) Compact Disc (650MB) Digital Versatile Disc (18GB)

1. Primary storage Devices 1. Datas are stored temporarily. 2. It is also called as online memory, because it is directly available to the processor. RAM (Random Access Memory) 1. It is also called as Read write memory, because in this memory we can read and if necessary write datas. 2. It is a volatile memory that is it loses its contents when the power supply is switched off. 3. Therefore in RAM we store application programs. ROM (Read Only Memory) 1. Here we can only read datas, we can’t write anything. 2. It is a nonvolatile memory that is it does not lose its contents when the power supply is switched off. 3. Here we store system programs. Secondary Storage Devices 1. It is a permanent storage device 2. It is also called as offline memory, because the processor does not access this device. Classification of Computers 1. Based on calculations Digital computer

1. It works with binary numbers 2. It works on the method of counting process 3. It performs only addition operation. 2. Analogue computer Analogue - comparison It compares the similarities between two quantities. It works on the basis of measuring process 3. Hybrid computer It has both the good qualities of analogue and digital computer. MODEM - Modulation and Demodulation device It converts analogue signal to digital signal and similarly digital to analogue 2. Based on speed and storage capacity Micro computer 1. Moderate speed 2. Good performance 3. Well suitable for all purpose 4. Moderate cost Mini computer 1. Very small in size 2. Low speed 3. Less storage 4. Used only for lower end applications Mainframe computer 1. High storage 2. Fast speed 3. Used as workstations Super computer 1. Very high storage 2. Fastest computer 3. High cost 4. Used in research centre Difference between hardware and software Hardware Software 1. Physical components are called set of programs are called As hardware as software. 2. It is the heart of the computer it is the brain of the computer 3. It has permanent structure it has no permanent structure And cannot be changed and can be modified. 4. It is affected by dust, heat, humidity Software is not affected by Etc these agents to some extent. 5. It understands only machine language it is written in high level Language 6. It works with binary codes (0 & 1). It works on the basis of high level language. Eg: Basic, FORTRAN Computer Languages 1. Machine language 2. Assembly language (It works with pneumonic codes) 3. High level Language.

Software Two types 1. System software or operating system 1. It is a set of one or more programs designed to control the whole computer. 2. It is the bridge between hardware and software. 3. It is the interface between user and computer. 2. Application software or packages It is set of one or more programs designed for particular applications. Eg: Ms-office, Tally Operating system Two types 1. Single user os 1. At a time only one user can use the system 2. At a time only one application can be run. 3. Communication not possible 4. Datas cannot be exchanged. eg: MS-Dos 2. Multi user os 1. At a time more than one user can use the system 2. At a time more than one application can run. 3. Communication is possible 4. Datas can be exchanged between different applications Eg: Windows 95, 98, 2000, UNIX, linux. Computer Virus Computer virus is executable computer programs... Viruses do the following 1. Damage the datas on hard disk. 2. Corrupts programs 3. Deletes files 4. Reformat our entire hard disk. 5. Infects executable program files such as word processors, spread sheet programs. Etc. Virus categories 1. Program viruses These viruses infect program files, which commonly have extensions such as .COM, .EXE, .SYS, .DLL, .OVL, .SCL 2. Boot viruses Boot viruses infect the non file areas of hard and floppy disks. 3. Macro viruses Macro viruses infect the data files with macro capabilities. Prevention methods 1. Launch antivirus programs Eg: Norton antivirus Antivirus program Antivirus monitors our computer for known and unknown viruses. A known virus is one that can be detected and identified by name. An unknown virus is one for which antivirus does not yet have a definition.

Windows It is a multi user operating system. Features of windows environment 1. Graphical user Interface (GUI) It means interacting through graphical methods with the users. 2. Graphical Device Interface It includes a graphics programming language GDI that allows the easy display of graphics and formatted text on the output media. 3. Virtual Memory It is a concept used to optimize memory. Some times a program can be larger than the memory available. In such cases windows loads the program in parts. 4. Dynamic data exchange (DDE) It is a technique by which data is transferred between different windows programs. To do this both the programs must be started. The program is then linked and data can be transferred between them. 5. Object Linking and Embedding (OLE) It is different from DDE that is here both the programs need not be running simultaneously 6. Networking Here we can communicate with the whole world through internet connection. Introduction to windows screen When we switch on the computer, what we see on the screen is the windows Desktop. The small pictures on the desktop are called as icons. Representing certain files and folders and programs. The long bar at the bottom of the desktop is called as taskbar. On the left side of the taskbar we see a start button and on the right side three is a timer. Items on the desktop 1. My computer It displays all the programs, files and folders in our computer. 2. My documents It displays all the documents in our computer. 3. My network places It displays the different type of network connection that we have made in our computer. 4. Internet explorer It is browser software. It is used to search information on the internet. 5. Recycle bin It stores all the deleted files and folders... But we cannot delete the recycle bin. Items on the start button Programs This contains several software programs that we have installed in our computer. Documents This submenu contains a list of files that we recently created or viewed. Click on the file name to open the file. Settings This submenu contains options to change the settings of our computer according to our needs. The items in this submenu are control panel, Printers, Taskbar & Start menu, Folder options, Active Desktop and windows update. Search This options help to search files and folders in our computer or WebPages on the internet. The items in this submenu are: Files and Folders, Computer, on the Internet, People, Using Microsoft outlook etc.

Help The help menu contains answers to various questions about windows and solutions to problems in our computer. Logoff If windows is configured to be used by more than one user, the user will have to click on Logoff to quit. Logging off does not shutdown the computer. Run Used to run software programs Shutdown Used to shutdown the computer. File A file is nothing but a collection of related information.Computer treats everything as a file. There are different types of files available in a computer. These files may have extensions .txt, .doc, .dot, .xls, .xlw, .htm, .dll, .exe etc. Folder A folder is a place where we can store our files.i.e it is a collection of files and subfolders folder can contain n number of files and subfolders. To create a folder 1. First decide where we want to create our folder.i.e c: or d: or my documents etc. 2. For eg if we want to create our folder in d: --> select my computer--> d: --> 3. There are two ways to create a folder. A0 Using Right click on the mouse. b) Using File menu. A) Using right click on the mouse 1. Right click the mouse 2. A window will open 3. on that window select--> New--> Folder. 4. A folder will appear asking the name. 5. Type the name of the folder. b) Using File menu. 1. On File menu select New--> Folder. 2. A folder will appear asking the name. 3. Type the name of the folder. To create a subfolder. 1. Select the folder where we want to create a subfolder. 2. Then as described earlier create a folder. To create a file 1. First decide where we want to create our file.i.e c: or d: or my documents etc. 2. For eg if we want to create our file in d: --> select my computer--> d: --> 3. There are two ways to create a file. A0 Using Right click on the mouse. b) Using File menu. A) Using right click on the mouse 1. Right click the mouse 2. A window will open 3. on that window select--> New. 4. A list if files will be displayed. 5. Select the type of the file that we want to create. 6. A file will appear asking the name. 7. Type the name of the file.

b) Using File menu. 1. On File menu select New. 2. A list if files will be displayed. 3. Select the type of the file that we want to create. 4. A file will appear asking the name. 7. Type the name of the file. Creating a shortcut 1. Select the application by browsing through my computer. 2. Right click on the mouse. 3. A window will open. 4. On that window select send to-->Desktop (Create shortcut). 5. We can also create shortcut using file menu. Some important Accessories program Notepad It is a word processor program used to create simple documents. The extension for notepad file is .txt.In notepad we cannot align the text. File Menu New It is used to open a new blank document. Open It is used to open an already existing document. Save It is used to save a newly created document. Save as It is used to save an already existing document (or) it is used to create a duplicate copy of a document. Page setup It is used to set the paper size, Margins, Orientation, Header and footer etc before printing a document. Paper size - size of the paper to be used in print out Margins - Indicates the left, right, top, bottom margins .Normally it is automatically setted when we set the paper size. Orientation - Portrait (lengthwise) Landscape (Breadth wise) Header - If we want to print a matter in all the pages we can set that message in header. It will automatically come in all the papered: (company name, date, time, page no) Footer - If we want to print a particular message in all the paper we can give it in the footer section. It will automatically get printed in all the pages.eg: (company name, date, time, page no) Print It is used to print a document. Exit It is one of the methods to come out from the notepad application. Edit Menu Undo This command will do the opposite action that we have done recently. It will automatically set according to our last action. Cut This command is used to cut a particular portion in a document. It will be highlighted only if we select a particular portion in a document. Copy

This command is used to copy a particular portion in a document from one place to another place. It will be highlightedcc only if we select a Particular portion in a document. Paste This command is used to paste a particular portion in a document. It will be highlighted only if we use cut or copy command. Delete It is used to delete a particular portion in a document. It will be highlighted only if we select a particular portion in a document. Find This command is used to find a particular text in a document. Find Next It is also used to find the text in a document. But it is used to find the text if the text is present in more than one place. Replace This command is used to replace an alternative text for particular text. Go to This command is used to go to anywhere in the document. Select all This command is used select the complete document. Time/Date This command will insert the time and date in the document automatically. Format Menu Word Wrap If we select this command before typing a new document the text will come automatically down after reaching the end of the window while typing. If it is not selected the text will not come down. Font It is used to set the font, font style and font size etc. Help Menu Help topics We can get help about any topic in notepad in this command. About Notepad This will tell about the hardware details. Word Pad It is also a word processor program used to create simple documents. The extension for WordPad document is .rtf. In WordPad we can align the text. Most of the commands are similar to notepad. File Menu New It is used to open a new blank document. Open It is used to open an already existing document. Save It is used to save a newly created document. Save as It is used to save an already existing document (or) it is used to create a duplicate copy of a document. Print It is used to print a document. Print Preview

It is used to see the preview of a document before taking print out. Page setup It is used to set the paper size, Margins, Orientation, Header and footer etc before printing a document. Paper size - size of the paper to be used in print out Margins - Indicates the left, right, top, bottom margins .Normally it is automatically setted when we set the paper size. Orientation - Portrait (lengthwise) Landscape (Breadth wise) Header - If we want to print a matter in all the pages we can set that message in header. It will automatically come in all the papered: (company name, date, time, page no) Footer - If we want to print a particular message in all the paper we can give it in the footer section. It will automatically get printed in all the pages.eg: (company name, date, time, page no) Send It is used to send a document in mail. Exit It is one of the methods to come out from the notepad application. Edit Menu Undo This command will do the opposite action that we have done recently. It will automatically set according to our last action. Cut This command is used to cut a particular portion in a document. It will be highlighted only if we select a particular portion in a document. Copy This command is used to copy a particular portion in a document from one place to another place. It will be highlighted only if we select a Particular portion in a document. Paste This command is used to paste a particular portion in a document. It will be highlighted only if we use cut or copy command. Paste special It is used to paste links and embedded objects. Clear It is used to clear a particular portion in a document. It will be highlighted only if we select a particular portion in a document. Select all This command is used select the complete document. Find This command is used to find a particular text in a document. Find Next It is also used to find the text in a document. But it is used to find the text if the text is present in more than one place. Replace This command is used to replace an alternative text for particular text. View Menu Tool Bar This will display the standard tool bar if selected. Format bar This will display the formatting toolbar if selected. Ruler

This will display the ruler if selected. Status bar This will display the status bar if selected. Options This is a setting. We shouldn't change this setting. Insert Menu Date and Time This command will insert today's date and time in a document. Object This command is used to insert other applications in our document. Format Menu Font It is used to set the font, font style and font size etc. Bullet style If we want to type point by point in our document we can select this command. Paragraph It is used to change the alignment. Tabs It is used to set the tab stop position. Help Menu 1. Help topics (F1) We can get help about any topic in WordPad in this command. 2. about WordPad This will tell about the hardware details. Paint This application is used to draw pictures, objects etc.The extension for paint is.BMP File menu New It is used to open a new blank document. Open It is used to open an already existing document. Save It is used to save a newly created document. Save as It is used to save an already existing document (or) it is used to create a duplicate copy of a document. Print It is used to print a picture Print Preview It is used to see the preview of a document before taking print out. Page setup It is used to set the paper size, Margins, Orientation, Header and footer etc before printing a document. Paper size - size of the paper to be used in print out Margins - Indicates the left, right, top, bottom margins .Normally it is automatically setted when we set the paper size. Orientation - Portrait (lengthwise) Landscape (Breadth wise) Header - If we want to print a matter in all the pages we can set that message in header. It will automatically come in all the papered: (company name, date, time, page no)

Footer - If we want to print a particular message in all the paper we can give it in the footer section. It will automatically get printed in all the pages.eg: (company name, date, time, page no) Send It is used to send a document in mail. Set us wall papers :( titled) Here we can draw a picture&set this picture we background of the desktop Set us wall paper :( centered) This is same us set us wall paper titled the only difference is here the picture is selfed in the center of the desktop Exit It is one of the methods to come out from the notepad application. Edit menu: Undo This command will do the opposite action that we have done recently. It will automatically set according to our last action. Repeat This command will repeat the last action that we have done recently. Cut This command is used to cut a particular portion in a document. It will be highlighted only if we select a particular portion in a document. Copy This command is used to copy a particular portion in a document from one place to another place. It will be highlighted only if we select a Particular portion in a document. Paste This command is used to paste a particular portion in a document. It will be highlighted only if we use cut or copy command. Clear Selection This command is used to clear the selected part of the picture. Select all This command is used select the complete picture... Copy to: We can copy our picture to another document Paste from: In this command used can paste document information into our file View Menu Toolbox Using this we can hide/unhide the toolbox Color box Using this we can hide and unhide the color box Status bar Using this we can hide/unhide the status bar Text toolbar This will be activated automatically when we select the text tool button. Using this we can change the font, fontsize etc. Zoom Using this we can zoom the picture as large as we can View bitmap Using this we can view the picture as bitmap picture.

Image menu: Flip rotate: This command is used to rotate the picture according to our wish Stretch skew: Here use can adjust the picture in any direction as use like Invert colors: This command displays the contrast color of any color Attributes: We can adjust the height, width and also we can convert a picture into black white Clear image: This command will erase the entire content of the click board Color menu: Edit colors: This command is used to edit any color as we like Help Menu Help topics We can get help about any topic in paint in this command. About Paint This will tell about the hardware details. Windows explorer Windows explorer is an easy-to-use file manager with which you can manage your files and folders. You can create, rename, and move files and folders with this program. Windows explorer has two panes (frames). The left pane shows a list of drives, folders and files in your computer .the right pane displays a list of files and folders in the selected folder. To select a folder in the left pane, click on the folder icon. You can move or copy a file or a folder by clicking on them and dragging it to the desired folder in the other pane. There is another application called my computer that acts like windows explorer. You can see it on your desktop. But windows explorer is more advanced and therefore has more features. 1. In the start menu, click on programs and then on windows explorer. 2. The left pane shows all the drives and folders in the computer. To view the contents of a drive or a folder, click on the + symbol before a drive or a folder icon. The list expands. 3. Windows explorer shows the contents of the drive/folder you selected. A folder may contain many folders. To view the contents of a folder, click on the + symbol before the folder icon. 4. When you click on the folder’s name, the contents of the folder are displayed on the right pane. To open a folder on the right pane, you an also double click on the folder. 5. If you click on the “-“(minus) symbol before the folder icon in the left pane, the list collapses or shrinks. To view the full list, click on the + symbol again. 6. This toolbar in windows explorer makes the program easier to use. When you are moving to one folder to another, the back button gets activated. If you want to go to the previous folder you viewed, click on the back button. If you want to view the folder you first saw, keep clicking on the back button until you reach the desired folder. 7. The forward button works the same way as the back button. Click on the forward button to move to the next folder you had already viewed. 8. If you want to jump to a drive or My Documents folder, click on the address drop down list below the toolbar and select the drive or folder you want to view. 9. To jump to a particular folder or drive you were working on just a while ago, click on the file menu and select the desired folder/drive you want to view.

10. To view the parent folder of the current folder, click on the Up button in the toolbar. (Warning In doing all the operations you should be very very careful. Don’t test this with others files and folders and with system files. If you do this you will be severely punished by the centre head.) Moving Files and Folders When you open the windows explorer the screen will be divided into panes. The left pane contains the drives and the folders where your files and folders need to be moved. The right pane contains the fields and folders you need to move. 1. Press the file or folder you want to move and drag it to my documents folder icon in the left pane without releasing your finger from the mouse button. The documents icon will be selected. Release your finger now. 2. We can move more than one file simultaneously. 3. We can also do this by using cut, paste method form Edit menu. Copying Files and Fielders 1. Click the file or folder you want to copy. 2. In windows explorer Edit menu, click on copy. 3. Open the folder or drive where you want to place the file or folder you just copied. 4. Click on the edit menu and click on paste. 5. Now you can see the copy of your file/folder. Deleting files or Folders 1. Select the file / folder you want to delete (destroy). 2. Press Del key. 3. A window will open and ask you whether you surely want to delete the file and folder. 4. Click yes 5. The file folder will be deleted. Note: The deleted files and folders will be placed in the Recycle bin. Recovering files and folders 1. To recover the file/folder you accidentally deleted double click on Recycle bin 2. Click the file/folder you want to recover. 3. Click the restore the button. 4. The file will be restored. To errantly delete the file/folder 1. Double click on Recycle bin 2. Select the file/folder you want to delete permanently. 3. Press del key 4. The file will be deleted permanently