The document provides an overview of computer components, functionality, and data processing. It discusses how computers represent data using binary digits and ASCII codes. It also summarizes the different types of computer memory including RAM, ROM, and different storage units like kilobytes and megabytes. The central processing unit processes raw input data and sends output to devices. Memory temporarily stores data and instructions during processing.

1. LECTURE 2
Introduction to Information
Technology
Miss Madiha Khadim

2. Computer Functionality
OutputProcessInput

3. Input
• Input is any data or instructions entered into the computer. inputs can be the signals which are
received by the computer system. the computer can not anything by itself. it must need some
human or machine interaction to perform any task.
• The instructions can be given to system are:
I. Programs: What to do? How to do?
II. Commands: Specific Actions
III. User Response: An action can be done by answering any question asked from computer

4. Process
• Data Processing is a process that uses computer program to convert the
data into form to be able to run on a computer.
• Convert conversation raw data into information.

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• In simple words: step by step data can be converted into useful
information that can be usable are called Data Processing.
• Data Processing involved analyzing, sorting, summarizing and calculating.
• The systems which processed data into useful forms are called data
processing systems. in computer, the processing is done by CPU (Central
Processing Unit).

6. Output
• Output is the data that has been processed into useful forms. the computer
takes the input from the users, process it and produces output.
• Output can be text, audio, video, graphic, animations

7. Forms of Output
• Soft copy
“Soft copy is whatever you can see on the monitor
(screen). it is temporary, unprinted, not touchable that is why it is also non
tangible copy.”
• Hard copy
“Hard copy can be touched, it is also called tangible copy or printout.”

8. Components of computer
• Input devices
• System unit
• Output device

9. Input devices
• The components that used to enter data into computer are called input
devices.
• If you want to enter text into the computer, you can use keyboard as
input device.

10. System unit
• It includes all important components that take instruction and processes. It
is called cabinet box or tower.
• System unit takes instructions and process it. After processing the
instructions are send to output devices.

11. The System Unit?

12. Output devices
• The components that are used to take outputs from the computer are called
Output Devices.
• The device which is used to get the output as audio can be speakers or
headphones.

13. Components
• The CPU
• manipulates raw data into more useful form and controls the other parts of the
computer system.
• Primary storage
• temporarily stores data and program instructions during processing.
• Secondary storage
• devices store data and programs when they are not being used in processing.

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• Input devices
• convert data and instructions into electronic form for input into the computer.
• Output devices
• convert electronic data produced by the computer system and display them in a form
that people can understand.
• Communication devices
• provide connections between the computer and communications networks.

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• Buses
• Buses are circuitry paths for transmitting data and signals among the
parts of the computer system.

16. How Computers Represent Data
• All symbols, pictures or words must be reduced to a string of binary digits.
• A binary digit is called a bit and represents either a 0 or a 1.

17. How is a letter converted to binary form?
• Step 1.
The user presses the capital letter D (shift + D key) on the keyboard.
• Step 2.
An electronic signal for the capital letter D is sent to the system unit..

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• Step 3.
The signal for the capital letter D is converted to its ASCII (American
Standard Code for Information Interchange System) binary code and is
stored in memory for processing.
• Step 4.
After processing, the binary code for the capital letter D is converted to an
image, and displayed on the output device
.

19. Types of Computer Memory

20. Units of Memory
• Kilobyte KB or K 1 thousand bytes
• Megabyte MB 1 million bytes
• Gigabyte GB 1 billion bytes
• Terabyte TB 1 trillion bytes

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22. Random Access Memory (RAM)
• Used by the Computer as the working area
• Holds the working program, the data being processed and the interim
results
• Volatile - contents are erased if power is cut
• Can be accessed randomly: can get any piece of data directly.
• Faster than permanent storage

23. Read Only Memory
Memory read at high speed but not capable of being changed by program
instructions.
Read-only memory is a type of non-volatile memory used in computers
and other electronic devices. Data stored in ROM can only be modified
slowly, with difficulty, or not at all, so it is mainly used to store firmware
or application software in plug-in cartridges.

24. Software
• There are 2 different types of Software stored in a device, which are
application software and system software.