Allah: In The Name Of

In the name of

ALLAH Most merciful and beneficent.

Basics of IT VENUE: Computer Room Senior School The Fazlehaq College, Mardan

Day ONE: We will Cover the following terms/topics today:



What is COMPUTER?



What are SOFTWARE and HARDWARE?

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Types of SOFTWARE

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Constituents/Components of Computer System.

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How Computer STORE or PROCESS human

understandable DATA?

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COMPUTER MEMORY and its UNITS?

1st Topic for today: What is COMPUTER?

What you say … what really computer is? Should I tell you … OK .. Computer is nothing else but a human without feelings/emotions/tiredness/pains/boredom …. Now let’s have some technical answer for this …..

COMPUTER is an Electronic device that …….  Receives  Process  Store and  Retrieves the DATA given to it by we humans.

Now, lets think over this definition of computer in respect of humans. Human listen to some word with EAR (Receives/Input Data) Human then think over that word to recognize by BRAIN. (Processing Data) Human can then memorize that word in Memory for future. (Storing Data) Human can then pickup that same word from Memory to pronounce/say, if asked or needed later on.

(Retrieving/Output Data)

Point to note here is that in each and every function of Computer, Processing is involved. i.e. No function of computer can be performed without the help of Processor (BRAIN) of computer.

End of Topic Assessment 6. What is computer? 7. Main functions of Computer? 8. How computer is different from humans?

2nd

Topic of today:

What are SOFTWARE and HARDWARE?

Software and Hardware cannot be well defined without giving example of a human being. So, A Human Soul is what we can call SOFTWARE and Human Body is what can say is its HARDWARE. Both SOUL and BODY are interdependent and are must for a life to exist. If one of them is not there, we say XYZ is dead. Same is the case with Computer, if there is no software then hardware is of no use.

Now the technical definitions: HARDWARE: All the physical parts of a computer which we can touch and see are called Hardware of a computer system e.g. Mouse, Keyboard, Printer, Monitor, Scanner, Printer etc. SOFTWARE: All those parts of a computer which we can only see but cant touch are called Software of a computer system e.g. Windows, Media Player, Google Earth, Ms. Word etc.

Topic of today: Types of Software There are mainly two types of Software: 3rd

System Software Application Software System Software: This is the type of software that is specially designed for the computer itself i.e. the user (We humans) don’t needs it directly but the Computer needs it for providing an environment in which we can use it for our own projects/works. The best example of such software is: Microsoft Windows LINUX UNIX etc Other name used for System Software is Operating System. All the Hardware needs such type of Software for their functionality and they are also referred as HARDWARE DRIVERS.

Application Software: Now such type of Software are designed for USERS (All those people who use computer for their work/projects etc). But again I have to say that before using these software one must have to INSTALL System software because that is the soul of Computer System without which it will not be able to provide us the environment for doing our work in Application Software. Some examples of Application software are here: Microsoft Word Microsoft Internet Explorer Yahoo Messenger Media Player etc. Other name used for Application Software is Utility Programs.

4th Topic of today:

What are constituents/components of COMPUTER? As we now know that Computer performs four main functions. So based on these functions different parts or components of computer are defined for performing these functions as:  Input Unit  Output Unit  Storage Unit  Processing Unit

Storage Unit RAM

ROM

Input Unit

Output Unit

Processing Unit CU

ALU

Block Diagram of Computer System

As we all know the basic definition of SYSTEM…. Collection of different equipments connected together to perform individual jobs for achieving a specific common objective. e.g. Educational System, Health System, Respiratory System, Digestive System etc. Maybe a System can be made up of Sub Systems i.e. in human body there are different sub systems working together in collaboration with each other and their job is to make it sure that Body is ALIVE…

Constituents/Components of COMPUTER Input Unit: This is the Unit which is responsible for all the Input/receiving of DATA from outer world. All the Input devices are connected through this Unit to computer. This unit is not directly connected to the PROCESSOR (Brain) of Computer but through RAM i.e. All the inputted DATA first go to RAM and afterward travel towards PROCESSOR for further any actions. 

All devices which are used for INPUT of DATA are connected to this INPUT unit which is further connected to RAM while RAM is connected to PROCESSOR. We have different Input devices i.e.  Mouse  Keyboard  Scanner  Microphone  Bar Code Reader  Touch Screens etc

Output Unit: The Unit which is responsible for all the Output/retrieving of DATA from inside of the computer is called Output Unit and all the Output devices are connected through this Unit to computer. This unit is also not directly connected to the PROCESSOR (Brain) of Computer but through RAM i.e. All the outputted DATA first go to RAM and afterward travel towards Output Devices. Different Output devices are:  Monitor/Screen/Projectors  Printer  Speakers etc. 

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Storage Unit:

As it is clear from its name, this Unit is responsible for the overall storage of DATA in computer. This storage maybe Temporary or on Permanent basis. Basically we have two types of Storage: Primary Memory  RAM  ROM Secondary Memory RAM (Random Access Memory): This is the memory which is not permanent and vanished as computer shuts down, that’s why called Random Access Memory. To better understand this memory here is an Example …… …. ….

(Example in class) ROM (Read Only Memory): This type of memory is fixed/permanent in nature and is written by the manufacturer of the computers.

(Example in class)

Secondary Memory: Hard Disk (HD) Floppy Disk Compact Disk (CD) Digital Video Disk (DVD) Flash Disk etc All these devices are used for storing the data on permanent basis means one can wash it out only if he intends to do so otherwise the computer power failure cannot harm the data.

Processing Unit: This is the most important unit of the computer. It is also called Central Processing Unit (CPU). Because of its so much importance people normally use the word CPU for the BOX/Casing in which it is fixed with all other parts of computer i.e. Hard Disk, CD Drive, RAM etc. Parts of CPU:  Control Unit  Arithmetic and Logic Unit 

Last Topic for today:

Basic Unit of Computer Memory Come on …. What do you think ….how computer keeps all your data…. Your documents …. Your pictures…. Your sounds….. Your videos ….. Oh …there is a WRITER/INTERPRETER sitting inside that BOX who is continuously obeying your orders and keeps record of your each and every single click and press of button fromkeyboard ….WOOWOWooo No ….its not like that …. Then ……… ?

7

6

5

4

3

2

1

0

Here you can see set of 8 Cells/Boxes, each cell individually is called BIT. I have marked them as 0 to 7 as addresses of these cells. BIT stands fro Binary Integer, means the contents of these cells can only be either 0 or 1. Computer Memory has millions trillions of such cells in groups of 8 BITS called BYTE and all our DATA is written/stored in these cells. BUTTTTT how…………

ASCII CODES: American Standard Codes for Information Interchange These are the codes which are stored permanently in computer memory (ROM). Each alphabet (for example) has a code, and the computer understands it because of that particular code. For example: ASCII code for A is 65. Now as I told you that computer can only understand 0 and 1 so here we need to represent 65 which is code for A in 0 and 1 format.

0 7

0

1

0

0

0

0

1

6

5

4

3

2

1

0

20 = 1 21 = 2 22 = 4

Code for A = 65

23 = 8

Now 64 + 1 = 65

24 = 16

So Cells No 0 and 5 will be ON (1) while the

25 = 64

rest of Cells will be Off (0) to represent A in

26 = 128

Memory of Computer.

27 = 256

00100001 = 65 = A

In computer Memory A looks like 00100001 while we human see it as A

THANK YOU All…….