Lesson- 4 

BASIC PARTS OF A COMPUTER

Parts of a Computer

The basic parts of a desktop computer are the computer case, monitor, keyboard, mouse, and power cord. Each part plays an important role whenever you use a computer.

Computer Case

The computer case is the metal and plastic box that contains the main components of the computer. It houses the motherboard, central processing unit (CPU), the power supply, and more.

Computer cases come in different shapes and sizes. A desktop case lies flat on a desk, and the monitor usually sits on top of it. A tower case is tall and sits next to the monitor or on the floor. The front of the case usually has an on/off switch and one or more optical drives.

Most of the personal computers you can purchase today include tower cases, rather than desktop cases; however, some computers are being made with all of the internal components built into the monitor, which completely eliminates the tower.

         The monitor works with a video card, located inside the computer
case, to display images and text on the screen. Newer monitors usually have LCD (liquid crystal display) or LED (light-emitting diode) displays. These can be made very thin, and they are often called flat panel displays. Older monitors use CRT (cathode ray tube) displays. CRT monitors are much bigger and heavier, and they take up more desk space.

Most monitors have control buttons that allow you to change your monitor's display settings, and some monitors also have built-in speakers.

LED displays are actually LCD displays that are backlit with light-emitting diodes. This allows for greater contrast than a traditional LCD display.

Power Cord

A power cord connected to a surge protector

The power cord is the link between the power outlet and the power supply unit in the computer casing. If the power cord is not plugged in, the computer will not power on. To protect your computer from voltage spikes, you can plug the power cord into a surge protector. You can also use an Uninterruptable Power Supply (UPS), which acts as a surge protector and also provides temporary power if there is a blackout.

Keyboard

The keyboard is one of the primary ways we communicate with the computer and enter data. There are many different types of computer keyboards such as wired, wireless, ergonomic, multimedia, and more. Although there may be differences in the location of some keys or features, keyboards are very similar and allow you to accomplish basically the same tasks.

         Introduction

         The keyboard is like a typewriter as well as most        essential used input     device. It       is used for entering       characters (such as letters, numbers &    symbols) in          the    computer and also use to perform functions. It has many    additional keys that          let it do special    things, a typewriter cann't.

         Type of Keyboard

         There are two types of keyboards

i)         Standard Keyboard      

        

ii) Multimedia KBD

         The keys on your keyboard can be divided into   several groups based on          function:

Typing (alphanumeric) keys. These keys include the         same letter, number, punctuation, and symbol keys         found on a traditional typewriter.

Control keys. These keys are used alone or in          combination with other keys to perform certain    actions. The most frequently used control keys are     CTRL, ALT, the Windows logo key , and ESC.

Function keys(Hot key). The function keys are used         to perform specific tasks. They are labeled as F1, F2,     F3, and so on, up to F12. The functionality of these          keys differs from program to program.

Navigation keys. These keys are used for moving      around in documents or webpages and editing text.     They include the arrow keys, HOME, END, PAGE UP,          PAGE DOWN, DELETE, and INSERT.

Numeric keypad. The numeric keypad is handy for    entering numbers quickly. The keys are grouped together in a block like a conventional calculator or    adding machine.

         The following illustration shows how these keys are   arranged on a typical          keyboard.

ESC

                  Escape Character. The escape key, which is marked ESC on most keyboard's top left corner is basically used to exit or escape from programs & tasks. In may cases, it will have no effect at all. However, it can sometimes get you out of trouble by making the computer go back or escape to a previous screen.

F1

                  If you are in an application and you press this key, you will get its help file. Suppose, you are not in windows explorer or desktop, you  press this key, and you  will get windows help file. Suppose, you are in an application , and you want windows help file, press  windows key + F1, you will get windows help file.

                  You select a program on your desktop (icon) and press this key. You will be allowed to rename that programme. F2 + in combination with other keys.

F2

                  Ctrl + F2 Choose the print preview comman (in application software )

                  Alt+Shift+F2      Choose the save command.

                  Ctrl+Alt+F2 choose the open command.

F3

While you are working in windows explorer or desktop, you press this key and will get the “Find Files” window. You need not go to start then find. While you are working in MS Word (make your selection) and press Alt+F3 – Create an auto text entry box appears.

Shift+F3 – Change the case of the letters.

F4

                  While you are in Internet Explorer and you will press this key the address bar will open. If you want to close the selected window, press Alt+F4. When no windows are open if you press Alt+F4, you will see the shutdown screen. When you are in MS Word, press shift+F4 Cursor will move page wise from the first page.

                    Ctrl+F4 – Close the window.

                    Alt+F4 – Quit the word program.

F5

                  To refresh the active window, press F5 (Refresh or reload the page or document window). When you are in MS word and press this key, you will have the find and replace window – Go to (edit menu)

                    Shift+F5 – Move the previous revision.

                    Ctrl+F5 – Restore the document window size

                    Ctrl+Shift+F5 – Edit a bookmark.

                    Alt+F5 – Restore down the window size.

F6

                  To press this key in MS Word, you will go to the next pane or frame.

                    Ctrl+Shift+F6 – Open to another open MS Word document.

F7

                  Commonly used to spell check and grammar check a document in MS programs such as MS Word, Outlook etc.

                  Alt+F7 – Runs a Thesaurus check on the word   highlighted.

                  Alt+F7 – Find the next misspelling or grammatical error.

F8

                  This key used to enter the windows start up menu while booting the system, commonly use to get into windows safe mode.

                           Alt+F8 – To run a macro in MS Word.

                  Users have no use of this key in windows but press this key in MS Word it will update the selected fields.

F9

                  Shift+F9 – Switch between a field code and its  result.

                  Ctrl+F9 – Insert an empty field.

                  Alt+F9 – Switch between all field codes and their    results.

                  In MS Windows activates the menu bar of an open application. Users have no use of this key in windows. In MS Word :-

F10

                  Shift+F10 – Display a shortcut menu.

                  Ctrl+F10 – Maximize the document window.

                  Ctrl+Shift+F10 – Activate the ruler.

                  Alt+F10 – Maximize the program window. 

                  Full screen mode in all modern Internet browser. In MS Word to press this key the cursor/pointer will move to next highlighted hyperlink field.

F11

                  Shift+F11 – To to the previous field (Hyperlink)

                  Ctrl+F11 – Lock a field

                  Ctrl+Shift+F11 Unlock a field

                  Alt+F11 – Display MS Visual studio code.

F12

                  Open the save as window in MS Word.

                  Shift+F12 – Save the MS Word document.

              Ctrl+Shift+F12 – Prints a document.

Print Scrn Sys Rq

                  Usually located at the upper right hand corner of keyboard next to the scroll lock and pause/break keys. Print screen key is a useful key supported on most PCs. In DOS, pressing the print screen key causes the computer to send whatever images and text are currently on the display screen to the printer. Some graphics programs and windows, use the print screen key to obtain screen captures. Pressing this key will copy whatever on the screen and that image can be pasted wherever necessary (e.g. Word, Excel, Powerpoint etc.) using paste (Ctrl+V) command.

Pause Break

                  Pause : This button pauses the display of data as it scroll on a screen. It doesn’t really have a function in modern programs, but was more prominent in the good old days of old computer. In DOS it is the same as using the MORE command which displays information on screen at a time (before scroll bars came along). It’s used in various other ways to pause things in programs.

                  Break : This goes back to when people still used telegraph. Telegraph was used to send morse code signals through lengths of wires that stretched over very great distances. This allowed messages to be sent quickly and  easily. When the telegraph wasn’t in use, a steady signal was sent down the line. The break key could be used to stop the signal, indicating a message was about to sent.

1.       

TAB

This key can be used to move forward through options in a dialog box.

2.        Ctrl+Shift+Tab – can be used to move backward through the options.

3.    Ctrl+Tab – allows movement from one open window to the next in an application with more than one open window.

4.    Alt+Tab – displays a list of open application widows. Keeping Alt depressed and selecting Tab cycles through the list. Releasing selects the highlighted application window.

5.    In word TAB shift the cursor on line.

CAPS                           LOCK

                  Locks the keyboard in “Capitals” mode ( only applies to Alpha Keys). The Caps Lock key should be used with caution. Using all CAPS is a usability no-no as many have difficulty scanning text that is all CAPS. Also when sending email in All CAPS, this could be misconstrued as shouting at some one.

                  Ctrl+Shift+A                                                                                         

Shift

                  This is toggle switch (if small letter printing  then by pressing shift CAPITAL LETTER print on the screen. If CAPS ‘ON’ then small letter will print on the screen although pressing shift key. 0 to 9 are not effect in toggle mode. This key is to allow selection of capital letters when depressing the alphabet characters, or selecting the characters above other non-alpha keys.

                  Depressing the shift key while inserting a CD-ROM will bypass auto play.

Ctrl

                  Shift+Delete – To permanently delete a selected  items, bypass the Recycle Bin.

                  Ctrl key is known as Control key also indicate Ctrl as (^) symbol. Depressing the Ctrl key while clicking allows multiple selections. Holding the Ctrl key down and pressing other key combinations will initiate quite a few actions. Some of the more common ones are as under :-

                  Ctrl+A – Select all items

                  Ctrl+B – Add or remove bold formatting.

                  Ctrl+C – copy on the clickboard                

                  In MS Office.

                  Ctrl+N – Opens a new window

                  Ctrl+P – Print

                  Ctrl+S – Save.

                  Ctrl+V – Paste command.

                  Ctrl+F6 – When more than one window is open, switch to the next window.

ÿ

                  Windows Key: On either side of the spacebar, outside the Alt key is a key with the windows logo. Holding the windows key down and pressing another key will initiate quite a few actions. Some of the more common   as under:-

                    To press windows key – Display the start menu.

                   Win Key +D – Minimizes all windows and shows the desktop.

                    Win Key+E – Opens a new explorer window.

                    Win Key+F – Displays the Find all files dialog box.

                    Win Key+M – Minimize all open windows.

                  Win Key+Shift+M – Restores all previous open windows to how they were before you minimized them.

                  Win Key+R – Displays the Run command.

                  Win Key+Pause/Break – Displays the systems properties dialog box.    

ALT

                  Located on either side of the space bar. Holding the Alt key down and pressing another key will initiate various actions. Some of the more common ones are as under:-

                  Alt+Space Bar+C – Pressing these combination keys will close a window. This works the same way as Alt+F4 but requires less stretch.

                  Alt+Tab – Displays a list of open application windows. Keeping Alt depressed and selecting TAB cycles through the list. Releasing selects the highlighted application window.

                  Alt+F4 – Close the current active window. If there is no active window this opens the shut down dialog box.

                  ALT+F5                                                    App Restore                  

                  Alt+Ctrl+M                                               For Annotation

                  ALT+F10                                                  App Maximize                 

                   ALT+CTRL+1                                           Apply Heading1               

                  ALT+CTRL+2                                            Apply Heading2               

                  ALT+CTRL+3                                            Apply Heading3  

                  ALT+CTRL+I                                            Print Preview            

                  ALT+CTRL+K                                            Auto format

                  ALT+CTRL+S                                            Document Split

                  ALT+CTRL+Home                                     Browse Selection

                  ALT+CTRL+NUM  +                                   Customize Keyboard

                  ALT+CTRL+NUM + -                                 Customize Remove Menu

                  ALT+CTRL+F                                            Footnote Now

                  ALT+SHIFT+D                                          Date Field

                  ALT+SHIFT+F7                                         Dictionary

                  ALT+Page Down                                       End Column

                 

Space Bar

Insert a space between works or characters. It is suggested that to utilize TABs to put distance between elements.

Enter

                  It creates a new line or paragraph or what is referred to as hard  return. This key is also located  in numeric key pad and function is same.

S

                     Shift+Inter Creates a new line break is referred to as soft return.

Back Space

                  While working with text, use this key to delete characters to the left of the insertion point.

Insert

To insert any character or words in a line. This key can been seen in two locations. One is at navigation key area another at numeric key pad and it will function when NUM Lock LED is Off.

Home

                  Depress and hold the Ctrl key as select. It is located at two places. One is at navigation key area and another is at numeric key pad and it will function when NUM Lock LED is Off.

PageUp

                  In a browser window use the page up key to move up one full screen. It is located at two places. One is at navigation key area and another is at numeric key pad and it will function when NUM Lock LED is Off.

Delete

                  While working with text, use this key to delete characters to the right of the insertion point. This key can also be used to delete selected files/folders. If this key use the keyboard combination Shift+Delete the item is permanently deleted, bypassing the Recycle Bin. This key is also located at two places. One is at navigation key area and another is at numeric key pad and it will function when NUM Lock LED is Off.

End

                  Depress and hold the Ctrl key as select End to go to the last line of a document. If only press this key to go to the end of that line. It is located at two places. One is at navigation key area and another is at numeric key pad and it will function when NUM Lock LED is Off.

Page Down

                  In a browser window use the page down  key to move down one full screen. It is located at two places. One is at navigation key area and another is at numeric key pad and it will function when NUM Lock LED is Off.

The mouse is a peripheral that is known as a pointing device. It lets you point to objects on the screen, click on them, and move them.

There are two main types of mice: optical and mechanical. The optical mouse uses an electronic eye to detect movement and is easier to clean. The mechanical mouse uses a rolling ball to detect movement. Generally, a mechanical mouse is cheaper, although it may require regular cleaning to keep it working properly.

Traditionally, a mouse connects to the computer using a USB or PS/2 connection. However, you can also buy a wireless mouse, which can reduce clutter on your desktop.

It is an input device. A computer mouse is used to tell        a computer what to do, including moving the cursor    and choosing things on the screen. It got its name because the wire coming out of the end of the first      computer mice reminded people of the tail of a real         mouse.

Many mouse today are wireless and use   batteries.

Wireless Mouse

How to connect with Computer :-

PS/2 mouse have round connector that connects to the green socket of the system adjacent to keyboard connector. USB mouse is also available can be connected to any USB port available on the computer.

Left Click :        

Press the left mouse button once to select desired files/folders or Icons on desktop.

Double Click :

Press the left mouse button twice rapidly to open desired files/folders or run selected programs.

Right Click :

Press the right mouse button to display additional features on that particular windows which is presently open.

Scroller :

         Scroller is used to move the page up or down quickly.

Uses :         On most computers, the user can move the mouse to move the cursor in the same direction. If there is something on the screen that the user wants to choose, he can move the cursor over it and “Click” the mouse button. The right mouse button is used to open menus that are different depending on where the cursor is. The other mouse buttons can do different things, depending on the software. Most mouse have two or three buttons. Mouse also have a “Scroll Wheel” – a small wheel found between the two main mouse buttons. The user can move the wheel up or down to “Scroll.”

Mouse Alternatives

There are other devices that can do the same thing a mouse can do, but with a different look and feel. Many people find them to be easier to use, and they also require less desk space than a mouse. The most common mouse alternatives include:

A touchpad on a laptop

Trackball: A trackball has a ball on top that can rotate freely. Instead of moving the device like a mouse, you can simply roll the ball with your fingers to move the pointer. Some mobile devices have miniature trackballs that can be controlled with your thumb.

Touchpad: A touchpad (also called a track pad) is a touch-sensitive pad that lets you control the pointer by making a "drawing" motion with your finger. Touchpads are very common on laptop computers.