Introduction to Computer Science

ICS

Introduction to Computer Science.

What is computer?

Computer is a solving machine. It has main four parts.

1.    System Unit

2. Monitor

3. Keyboard

4. Mouse

System unit is the main part of computer. It is a box / case. It has two shapes. 1) Desktop 2) Tower. It includes Motherboard, Power supply, RAM, Expansion Slots, Processor (CPU), Hard Disk, CD (Compact Disc) and Floppy Disk drive.

    Hard Disk                           Compact Disc

			G:

 

CPU

CPU (Central Processing Unit). It is also called the brain of computer. All parts talk with each other through it.

ALU

Arithmetic and Logical Unit

CU

Control Unit

MU

Memory Unit

1.    Internal Memory

In-erasable    

2.    External Memory

Erasable

   Math signs and Operators.

+       Plus            2 + 2 = 4

-        Minus        3 – 2 = 1

*        Multiply    7 * 2 = 14

^        Power        2 ^ 3 = 8

/        Divide        10 / 2 = 10

< Lesser than                > Greater Than

= Equal to                    < > Not Equal

<= Lesser and Equal   > = Greater and Equal

Monitor

It is an output device, where we can see our program and result of program.

Keyboard

It is an input device where we can type our program or data.

Mouse

It is a pointing device used as input device

Complete A to Z is available in the following sentence.

A quick brown fox jumps over the lazy dog.

Home keys for learning typing

asdf ;lkj asdf ;lkj asdf ;lkj asdf ;lkj asdf ;lkj asdf ;lkj asdf ;lkj

Function of Key Board

1.    ESC (Escape key). This key is used to close the menu or sub menu.

2.    F1 ~ F12 (Function keys Pad) these keys work different in different program. Normally F1 key is used to get help of current program.

3.    Tab this key is used to jumps the cursor at the specific location.

4.    Caps Lock This key is used to type UPPER CASE or lower case alphabets. if caps lock off (abc) or if caps lock on (ABC)

5.    Shift           This key is used to type upper signs of keys which they will define also used to change the mode of caps lock key.

6.    Ctrl (Control key) This key works with the combination of other keys. e.g. Ctrl + C (to copy) Ctrl + V (to paste)

7.    Windows key            This key is used to open Start menu program

8.    Alt This key is used to open the menu of program.

9.    BackSpacee        This key is used to remove the character(s) left side of cursor.

10.                       Space Bar. this key is used to provide the space between the words and also used to confirm the commands in some program such as AutoCAD

11.                       Enter        This key is used to change the line while typing and used to confirm the current command

12.                       Print Screen This key is used to capture the current screen that can be paste any where.

13.                       Scroll Lock this key is used to on / off scroll function

14.                       Pause/Break This key is used to pause or break the program if specify.

15.                       Insert. This key is used to type missing character(s)

16.                       Home. This key is used move the cursor at the start of current line.

17.                       Page Up/Down . to move the cursor at the top or bottom of page

18.                       Delete/Del . This key is used to Delete the  selected text or object or character(s) over the cursor.

19.                       END. To move the cursor at the end of current line.

20.                       Arrow Keys             To move the cursor

21.                       NumLock. This key is used to on / off Numeric key pad

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About Mehtab Alam