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ACT – ASSOCIATION OF COMPUTER TEACHERS
MALAPPURAM
ComprehensiveStudy Notes on
COMPUTER SCIENCE
CLASS XI
Contents
1 The discipline of Computing 2
2 Data Representation and Boolean Algebra 6
3 Components of Computer System 15
4 Principles of programming and problem solving 24
5 Introduction to programming 28
6 Data types and operators 30
7 Control Statements 35
8 Arrays 40
9 String handling using I/O functions 45
10 Functions 47
11 Computer networks 52
12 Internet and mobile computing 60
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2
CHAPTER 1
The discipline of Computing
Computing milestones and machine evolution
1. Development of number systems:
Origin Base Features
Egyptians (3000 BC) 10 • Right to left
Sumerian/ 60 • Sexagesimal system
• Left to Right
Babylonian
• Used blank space for 0
Chinese (2500 BC) 10 • Used bamboo rods to represent digits
India (1500 years • Invented a symbol for zero
ago) • Positional decimal system
• Hindu-Arabic Numeral system
Greek (500 BC) 10 • Ionian number system
Roman Numeral • 7 letters[ I, V, X, L (50 ),C (100),
D(500), M (1000 ) ]
Mayans 20 • Great accuracy
Evolution of the computing machine:
1.Abacus:
• means calculating board.
• Discovered by the Mesopotamians.
• Used for arithmetical calculations.
2. Napier's bones.
• John Napier invented a set of numbered rods to simplify multiplication process (Napier's
bones).
• He also invented logarithm.
3. Pascaline:
• Blaise Pascal developed in 1642
• can perform arithmetical operations.
• Operated by dialling a series of wheels, gears and cylinders.
4. Leibniz's calculator :
• Leibniz designed a calculating machine called step reckoner.
• Expanded on Pascal’s idea to perform multiplication and division too.
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
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3
5. Jacquard's loom:
• Joseph Jacquard invented a mechanical loom to simplify a textile manufacturing
process.
• The loom controlled by punched cards had the ability to store information.
6. Difference Engine
• Developed by Charles Babbage
• compile mathematical tables, do arithmetical operations and print results automatically.
• Developed by Charles Babbage in 1833
• Had many essential features found in modern digital computer.
• Programmable using punched cards
• It had a store (memory) and a separate ‘Mill’ (Processor)
8. Hollarith’s Machine
• Herman Hollarith made first electromechanical punched card tabulator with input, output and
instructions.
• Used electricity to read, count and sort punched cards.
9. Mark-I Computer:
• Developed by Howard Aiken
• Could do all 4 arithmetic operations,logarithmic and trigonometric functions.
Generations of Computer
1) First generation computers:
• Used Vacuum tubes
• The ENIAC (Electronic Numerical Integrator and Calculator ), the
first general purpose programmable electronic computer(built by J. P. Eckert and John
Mauchly.)
• UNIVAC( UNIVersal Automatic Computer ). - first commercially successful computer
• Von Neumann designed EDVAC( Electronic Discrete Variable Automatic Computer )
with a memory to store program and data.( stored program concept)
2) Second Generation Computers :
• Vacuum tubes were replaced by transistors reducing size.
• less electricity, less expensive.
• Concept of programming language was developed. High Level Languages like FORTAN
(FORmula TRANslation), COBOL (COmmon Business Oriented Language) developed.
• Magnetic core memory (Primary memory ) and magnetic disk memory (Secondary
memory ).
• The popular computers are IBM 1401 and IBM 1620
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
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4
3) Third Generation Computers:
• Silicon chips or IC(Integrated Circuits) that contain very small transistors were
developed by Jack Kilby
• Transistors were replaced by IC's.
• It reduced size, increased speed and efficiency, and became cheaper.
• High Level Language BASIC (Beginner’s All Purpose Symbolic Instruction Code ) was
developed
• Moore's Law states that the number of transistors on IC's doubles approximately every two
years.
• The popular computers are IBM 360 and IBM 370.
4) Fourth Generation Computers:
• Microprocessors are used (a single chip with Large Scale of Integration (LSI) of electronic
components)
• Later LSI circuits were replaced by VLSI ( Very Large Scale Integration ).
• IBM PC and Apple II are popular computers. Programming Languages like. C, C++, Java etc.were
developed.
e). Fifth Generation Computers:
• They are based on Artificial Intelligence (AI).
• AI is the ability of machines to simulate human intelligence
• Presently in the development stage.
• Common AI programming Languages- LISP and Prolog.
Program:
The set of detailed instructions given to a computer for executing specific tasks.
Programming languages are artificial languages designed to give instructions to the computers.
• Machine language (Low Level Language -LLL).consists of 0's and 1's. This is the only language
understood by the computer.
• Assembly language, with English like words instead of 0's and 1's EDSAC (Electronic Delay
Storage Automatic Calculator ) built in 1949 was the first computer to use assembly language.
• Later, High Level Languages (HLL) like, BASIC, C, C++, Java etc were developed.
Algorithm and Computer programs:
An algorithm is a step by step procedure to solve a problem.
Theory of computing:
• This branch deals with how efficiently problems can be solved based on computation models
and related algorithms. The study is based on a mathematical abstraction of computers called
model of computation.
• The most commonly used model is Turing machine named after the computer scientist Alan
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
ACT – ASSOCIATION OF COMPUTER TEACHERS
MALAPPURAM
ComprehensiveStudy Notes on
COMPUTER SCIENCE
CLASS XI
Contents
1 The discipline of Computing 2
2 Data Representation and Boolean Algebra 6
3 Components of Computer System 15
4 Principles of programming and problem solving 24
5 Introduction to programming 28
6 Data types and operators 30
7 Control Statements 35
8 Arrays 40
9 String handling using I/O functions 45
10 Functions 47
11 Computer networks 52
12 Internet and mobile computing 60
, Join Telegram Channel: https://t.me/hsslive Downloaded from www.Hsslive.in ®
2
CHAPTER 1
The discipline of Computing
Computing milestones and machine evolution
1. Development of number systems:
Origin Base Features
Egyptians (3000 BC) 10 • Right to left
Sumerian/ 60 • Sexagesimal system
• Left to Right
Babylonian
• Used blank space for 0
Chinese (2500 BC) 10 • Used bamboo rods to represent digits
India (1500 years • Invented a symbol for zero
ago) • Positional decimal system
• Hindu-Arabic Numeral system
Greek (500 BC) 10 • Ionian number system
Roman Numeral • 7 letters[ I, V, X, L (50 ),C (100),
D(500), M (1000 ) ]
Mayans 20 • Great accuracy
Evolution of the computing machine:
1.Abacus:
• means calculating board.
• Discovered by the Mesopotamians.
• Used for arithmetical calculations.
2. Napier's bones.
• John Napier invented a set of numbered rods to simplify multiplication process (Napier's
bones).
• He also invented logarithm.
3. Pascaline:
• Blaise Pascal developed in 1642
• can perform arithmetical operations.
• Operated by dialling a series of wheels, gears and cylinders.
4. Leibniz's calculator :
• Leibniz designed a calculating machine called step reckoner.
• Expanded on Pascal’s idea to perform multiplication and division too.
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
, Join Telegram Channel: https://t.me/hsslive Downloaded from www.Hsslive.in ®
3
5. Jacquard's loom:
• Joseph Jacquard invented a mechanical loom to simplify a textile manufacturing
process.
• The loom controlled by punched cards had the ability to store information.
6. Difference Engine
• Developed by Charles Babbage
• compile mathematical tables, do arithmetical operations and print results automatically.
• Developed by Charles Babbage in 1833
• Had many essential features found in modern digital computer.
• Programmable using punched cards
• It had a store (memory) and a separate ‘Mill’ (Processor)
8. Hollarith’s Machine
• Herman Hollarith made first electromechanical punched card tabulator with input, output and
instructions.
• Used electricity to read, count and sort punched cards.
9. Mark-I Computer:
• Developed by Howard Aiken
• Could do all 4 arithmetic operations,logarithmic and trigonometric functions.
Generations of Computer
1) First generation computers:
• Used Vacuum tubes
• The ENIAC (Electronic Numerical Integrator and Calculator ), the
first general purpose programmable electronic computer(built by J. P. Eckert and John
Mauchly.)
• UNIVAC( UNIVersal Automatic Computer ). - first commercially successful computer
• Von Neumann designed EDVAC( Electronic Discrete Variable Automatic Computer )
with a memory to store program and data.( stored program concept)
2) Second Generation Computers :
• Vacuum tubes were replaced by transistors reducing size.
• less electricity, less expensive.
• Concept of programming language was developed. High Level Languages like FORTAN
(FORmula TRANslation), COBOL (COmmon Business Oriented Language) developed.
• Magnetic core memory (Primary memory ) and magnetic disk memory (Secondary
memory ).
• The popular computers are IBM 1401 and IBM 1620
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
, Join Telegram Channel: https://t.me/hsslive Downloaded from www.Hsslive.in ®
4
3) Third Generation Computers:
• Silicon chips or IC(Integrated Circuits) that contain very small transistors were
developed by Jack Kilby
• Transistors were replaced by IC's.
• It reduced size, increased speed and efficiency, and became cheaper.
• High Level Language BASIC (Beginner’s All Purpose Symbolic Instruction Code ) was
developed
• Moore's Law states that the number of transistors on IC's doubles approximately every two
years.
• The popular computers are IBM 360 and IBM 370.
4) Fourth Generation Computers:
• Microprocessors are used (a single chip with Large Scale of Integration (LSI) of electronic
components)
• Later LSI circuits were replaced by VLSI ( Very Large Scale Integration ).
• IBM PC and Apple II are popular computers. Programming Languages like. C, C++, Java etc.were
developed.
e). Fifth Generation Computers:
• They are based on Artificial Intelligence (AI).
• AI is the ability of machines to simulate human intelligence
• Presently in the development stage.
• Common AI programming Languages- LISP and Prolog.
Program:
The set of detailed instructions given to a computer for executing specific tasks.
Programming languages are artificial languages designed to give instructions to the computers.
• Machine language (Low Level Language -LLL).consists of 0's and 1's. This is the only language
understood by the computer.
• Assembly language, with English like words instead of 0's and 1's EDSAC (Electronic Delay
Storage Automatic Calculator ) built in 1949 was the first computer to use assembly language.
• Later, High Level Languages (HLL) like, BASIC, C, C++, Java etc were developed.
Algorithm and Computer programs:
An algorithm is a step by step procedure to solve a problem.
Theory of computing:
• This branch deals with how efficiently problems can be solved based on computation models
and related algorithms. The study is based on a mathematical abstraction of computers called
model of computation.
• The most commonly used model is Turing machine named after the computer scientist Alan
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
