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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! ! arithmetic operations.
al
• 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.
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5. Jacquard's!!loom:
• Joseph! ! Jacquard!!invented!!a!!mechanical!!loom!!to!!simplify !! a!!textile !! manufacturi
ng ! ! 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!!a
nd!!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! ! (Sec
ondary!!memory!!).
• The! ! popular!! computers! ! are! ! IBM! ! 1401! ! and!!IBM!!1620
Preparedby :LijuMathew(MTHSS Chungathara) PriyaMD(GHSS Purathur) JessieMathew(GHSS Vaniyambalam)
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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!!efficien and!!became!!cheaper.
cy,
• 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!!electron
ic!!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.we
re!!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!!languag
e.
• 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!!mod
els!!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! ! arithmetic operations.
al
• 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 !! manufacturi
ng ! ! 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!!a
nd!!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! ! (Sec
ondary!!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!!efficien and!!became!!cheaper.
cy,
• 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!!electron
ic!!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.we
re!!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!!languag
e.
• 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!!mod
els!!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)
