Information and Communication Technology Chapter 1,2 ,3 - Dr.J.VijiPriya

Information and Information and Communication Communication

TechnologyTechnologyChapter 1- Introduction to ComputerChapter 2- Data RepresentationChapter 3-Computer System

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Presented by Dr.J.VijiPriya, Assistant Professor, Hawassa University,Ethiopia

Introduction to ComputerIntroduction to Computer Derived from Latin word ‘Compute’ means ‘Calculate’ Electronic Machine – performing arithmetic and

Logical operation Read input , process it ,display output and store data Applications:

◦ Medicine and Healthcare◦ Education◦ Science◦ Engineering and Technology◦ Government◦ Entertainment◦ Architecture and Agriculture

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Information and Information and Communication TechnologyCommunication Technology Technology merging computing with communication

links carrying data in the form of text, audio and video

Derived from combination of computers and communication

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Characteristics of Characteristics of ComputersComputers Automatic Speed Accuracy Diligence Versatility Power of Remembering No I.Q. No Feeling

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Presented by Dr.J.VijiPriya, Assistant Professor, Hawassa University,Ethiopia 4

Characteristics of Computers Characteristics of Computers Con…Con…

Automatic Once started on a job,carry on until job is finished without any human intervention

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Characteristics of Computers Characteristics of Computers Con…Con…Speed Very fast device (enormous speed) Units of Time

◦ Microseconds (10 -6 second)◦ Nanoseconds (10-9 second)◦ Picoseconds (10-12 second)

Performing billion (109) arithmetic operation per second

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Characteristics of Computers Characteristics of Computers Con…Con…Accuracy Consistently high Accuracy Degree of Accuracy depends

Upon computer design

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Characteristics of Computers Characteristics of Computers Con…Con…Diligence Free from boredom, tiredness and lack of concentration etc… Working for hours without error

and grumbling (upset)

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Characteristics of Computers Characteristics of Computers Con…Con…Versatility Performing almost

any type of task simultaneous Spread sheet, store data

process text and listen music etc…

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Characteristics of Computers Characteristics of Computers Con…Con…Power of Remembering Store and recall huge

amount of information because of its secondary memory

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Characteristics of Computers Characteristics of Computers Con…Con…No I.Q. Not a magical device No intelligence of its own Work based human instructions with unthinkable speed and accuracy

No Feeling Devoid of emotion No feeling and hungry Can not judge on its own but can,

based on user programs

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Classification of ComputersClassification of Computers

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Classification of ComputersClassification of ComputersCon…Con…Classification according to purpose General purpose computers

◦ designed for different purpose◦ Eg:- PC

Special purpose computers◦ Designed for a particular task◦ Eg:-Missile computer

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Classification of Computers Classification of Computers Con…Con…Classification according to type of data handled

techniques Analog Computer

◦ Process analog data such as time, temperature, speed, current, chemical composition of petroleum

productsEg:- Scientific and Engineering purpose

Digital Computer◦ Process digital data◦ Eg:-PC

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Classification of ComputersClassification of ComputersCon…Con…

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Classification according to type of data handled techniques Con…

Hybrid Computer◦ Perform analog and digital data◦ Use analog components for

differential calculation and digital memory, digital components for logical

operations

Classification of ComputersClassification of ComputersCon…Con…Classification according to Functionality Super Computers Mainframe Computers Microcomputers Minicomputers Workstations

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Classification according to Functionality con… Super Computers

◦ Fastest costlier and powerful ◦ Solve complex problems quickly◦ Eg:-CRAY and CYBER

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Classification according to Functionality con… Main Frame

◦ Second largest computer( in size and capability)◦ Serve hundreds and thousands of users◦ Handling massive amount of input, output

and storage◦ housed in special room, requires special

power and environmental control◦ Used as E-commerce centralized server for

transaction in Internet

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Classification according to Functionality con… Microcomputer

◦ Small, lowest digital computer ,Consists of microprocessor, storage unit,

◦ Input and output channel, PC board, Chip ◦ Designed for not only individual user, and designed for many user

on network , businesses ◦ Eg:- Desktop, Laptop and PDA (Personal digital Assistant)

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Classification according to Functionality con… Minicomputer

◦ Small digital computer◦ Process and store less data than a mainframe

but more than a micro computer◦ Multi-user computer◦ Used as desktop and sometime connected

with mainframe for performing auxiliary operations

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Classification according to Functionality con… Workstation

◦ Power single-user Computer◦ Designed for animation and product design◦ Used as Network and Internet Server

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Information and Information and Communication TechnologyCommunication Technology

Chapter -2 Data Representation

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Number SystemNumber System Around for thousand of years Defined as set of values to represent quantity and

other characters Two types

◦ Non positional:- special symbols or characters are used to indicate the values. difficult to perform arithmetic with such a numbers as it has no

symbol for zero◦ Positional:- indicates the value of each digit in a number used by Symbol or

the symbol’s position(called digits). have a base or radix. The base or radix tells the number of symbols used in the system

(called the decimal number system)

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Conversion between Conversion between Number SystemsNumber Systems Internally computers use binary numbers for

data representation whereas externally it uses decimal numbers.

However, any number in one number system can be represented in any other number system.

Conversion of Decimal to Binary Conversion of Binary to decimal

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Conversion between Conversion between Number SystemsNumber SystemsConversion of Decimal to Binary

1. Begin by dividing the decimal number by 2 ( the base of binary number system)

2. Write the remainder separately as the rightmost digit of the binary equivalent.

3. Continually repeat the process of dividing by 2 until the quotient is zero and keep writing the remainders after each step of division (these remainders will either be 1 or 0).

4. Finally, when no more division can occur, write down the remainders in reverse order (last remainder written first)

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Conversion between Conversion between Number SystemsNumber SystemsConversion of Binary to decimal1. each digit of the binary number is multiplied by its

weighted position2. each of the weighted value is added together to get

the decimal number.

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Unit of RepresentationUnit of Representation When data is stored, processed, or communicated within the

computer system, it is “packed” in units. Units are called bits, bytes, and words

based on the binary number system where large numbers can be conveyed using only two digits, 0 and 1.

Bits◦ Smallest unit◦ Each binary digit (bit) is represented by an on (1) or off

(0) state of a switch.

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Unit of RepresentationUnit of RepresentationBytes

◦ Largest unit, contains 8 bits

◦ The total amount of information that can be conveyed is 28 or 256 possible combinations.

◦ Combinations can represent letters, numbers, and symbols such as +,-,? etc…

◦ Computer’s memory processing, storage, and communication use the byte as a unit of measurement.

◦ indicate the size of memory like 128,000 bytes or 128K bytes ◦ The K indicate a magnitude of 1000. ◦ M (for Megabyte) -magnitude of 1,000,000. Gigabyte, or 1 billion bytes. 1000,000,000

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Unit of RepresentationUnit of RepresentationWords refers to the number of bits that a computer

processes at once

conveyed even faster by sending more than one byte at a time, two bytes, or four bytes.

Generally, word length is given in bits, (8 bits, 16 bits, or 32 bits).

The larger word length a computer has, the more powerful it is.

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Binary Coding Binary Coding commonly used coding standards: Binary Coded Decimal (BCD) American Standard Code for Information Interchange

(ASCII) Extended Binary Coded Decimal Interchange Code

(EBCDIC) Unicode

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Binary Coding Con…Binary Coding Con…The Binary Coded Decimal (BCD): BCD coding system represents numeric character (0-

9) by a combination of four bits Eg:- 256 is represented as 0010 0101 0110

2 5 6

Binary equivalents of the decimal digits (0-9) are given in the chart below.

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Binary Coding Con…Binary Coding Con…ASCII: American Standard Code for Information

Interchange basis for the internal coding scheme of most

computer system. Uses eight bits (one byte), which is four bits more

than BCD system, so as to represent 28 alphanumeric characters.

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EBCDIC: Extended Binary Coded Decimal Interchange Code

uses 8 bits (one byte) for each character, represent 256 different characters or bit combinations.

provides a unique code for each decimal value 0 to 9, each upper case and lower case letter and special characters.

Unicode standardized to accommodate special symbols such

as Greek characters α, β, γ etc. uses 16 bits to represent each character or symbol. ( 216

combinations) Virtually every character of every language can be

represented by using this code.

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Binary Coding Con…Binary Coding Con…

Information and Information and Communication TechnologyCommunication Technology

Chapter 3

Computer System

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Computer SystemComputer SystemComputer System group of hardware components and associated software, designed

and assembled to perform a specific function or group of functions complete computer system includes four distinct parts: Data,

Users, Hardware and Software.

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Computer SystemComputer SystemData Are raw facts which the computer can manipulate and process into

information that is useful to people Used for simple (mathematical) operations and complex (drawing,

picture) operations. The instructions that make up the program define what data is

to be processed, in what form and at what time. The computer reads and stores all data as numbers After processing semi-information (data) and generates

complete information used by human

User Are the people operating the computers

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Computer System Con…Computer System Con…Hardware embraces the physical components of the system and Integrated

circuit chip contain complex electronic circuits

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Computer System Con…Computer System Con…Hardware con… The box which contains the printed circuit boards, power supply,

display screen, keyboard and mouse for user interaction, peripheral devices such as disks and printers.

The internal electronic circuits of modern computers are made up from a number of integrated circuit chips and other components.

The heart of the modern computer is the microprocessor , integrated circuit chip containing the central processing unit of a small computer system

However, before the computer hardware can perform a task (for example add numbers or read a character from a keyboard), it requires a program to tell it what to do.

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http://www.infc.ulst.ac.uk/~desi/b94mn/regist.htm

Computer System Con…Computer System Con…Software Comprises the programs that tell the hardware what to do. A program is a sequence of instructions stored in the memory of

the computer system. The central processing unit fetches an instruction, decodes it and

then executes the required operation . A program may be very simple Eg:- calculate the average of ten

numbers, or very complex Eg:- draw a television quality picture on a display screen.

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