How does computer Memory work ?

•         How does works Information Processing Cycle in computer?

·        Input Data

Any data or instructions you enter into a computer system.

·        Process Data

Manipulate the input (data) to produce output (information)

·        Output Data

Data that has been processed into information

·        Storage Data

·        Area in a computer that can hold data and information for future use

·        Communication (Media)

·        The capacity of communicating with other computer systems.

Definition about Hardware and Software?

•         Hardware

•         Electronic and mechanical equipment in computer system.

•         Software

•         The sequence of instructions that tell hardware how to perform tasks or application packages runs on computers.

What is Data?

Raw facts, figures and symbols to be procedure by the computer (System).

Data indicates to all the basic things that can be produced and generated through computer.

What is Information?

Summarised or manipulated data that is useful for choice making

Importance of useful information:

       §       perfect

§        Relevant and meaningful

§        well-timed

§       Concise and complete

§       Prepare

•         Types of Data :-

1.      Analogue signals :-

Data or signals that have continuous wave’s forms (strength or quantity) that changes smoothly over time.

For Examples: Radio, Television, Telephone signals

2.      Digital signals :-

A digita Data or signals represented in a discrete form or binary that consists of 0s and 1s. The transition of digital signals from value to value is instantaneous like a light is being switch on or off.

                                      i.      A single digit is known as bit (binary digit)

                                     ii.      A bit is the smallest unit of data the computer can represent

Who is a user?

v     Person who communicates with a computer or uses the information it generates

v     Two types of users :

Ø      End-user

Ø      Power user

v     End-user

v     An end-user with reasonable technical knowledge of Information Technology (IT)  who uses computers for education, entertainment or work-related duties on their requirements,

v     Types of end-users :

Ø      Home-user -

Ø      SOHO user

Ø      Mobile user

Ø      Large business user

End-user	Software usage
Home-user	Business (e.g Word processing) Personal Information Manager Web browser Online banking E-mail, Instant messaging and Chat rooms Encyclopedias, Medical dictionaries Entertainment Educational
(SOHO) user	Business (e.g Word processing, Spreadsheet, Database) Personal Information Manager Company specific (e.g Accounting, Legal reference) Network management Web browser E-mail
Mobile user	Business (e.g Word processing, Spreadsheet, Presentation graphics) Personal Information Manager Web browser      E-mail
Large Business user	Mid-range server or mainframe Desktop or notebook computer Industry specific handheld computer PDA Kiosk Software Business (e.g Word processing, Spreadsheet, Presentation graphics)     Personal Information Manager §         Network management §         Web browser §         E-mail

v     Power user

v     A person who has extensive education or significant experience in the technical and functional aspects of using Information Technology  (IT) and Information Systems

v     Types of power users :

Ø      Engineering

Ø      Scientific areas

Ø      Architectures

Ø      Graphics Designing

Ø      Desktop publishers

•         How is memory measured?

Term               Abbreviation             Approximate Size

Kilobyte            KB or K                     1 thousand bytes

     Megabyte          MB                             1 million bytes

    Gigabyte            GB                             1 billion bytes

    Terabyte             TB                              1 trillion bytes

How do computers represent data?

v     Most computers are digital

v     Recognize only two discrete states : ON or OFF

v     Use a binary system to recognize two states
v     Use Number system with two unique digits: 0 and 1, called bits (short for binary digits)

What is binary digit?

v     Is the fundamental element of all data and information stored in a computer
         system

v     Consists of 0 and 1

v     Bits can be grouped in various combinations to represent characters of data

Ø      Numbers

Ø      Uppercase and lowercase Letters

Ø      Punctuation marks

Ø      Special characters
What is a byte?

v     Eight bits grouped together as a unit

v     Provides enough different combinations of 0s and 1s to represent 256
        individual characters

       

•         What are three popular coding systems to represent data?

1.   ASCII

•         Stands for American Standard Code for Information Interchange

•         Widely used binary code with non-IBM mainframes and virtually all microcomputers

•         Originally consisted of 7 bits for each character, now the more common extended ASCII uses 8 bits

2.    EBCDIC

Ø      Stands for Extended Binary Coded Decimal Interchange Code

Ø      Commonly used in IBM mainframes

Ø      Is an 8 bit coding scheme

3. Unicode

   Ø             A subset of ASCII

Ø            Uses 2 bytes (16 bits) for each character, instead of 1 byte (8 bits)

Ø           Coding scheme capable of representing all world’s languages

Ø           Takes up twice as much memory space and hard disk space