Ch 2 component of computer system

11

The parts of a computerThe parts of a computer

Keyboard Mouse

Speakers

Disk drive

Visual display unit/VDU/MonitorCentral processing unit (CPU)

Hard disk (Backing store)

Microphone

22

Hardware & SoftwareHardware & Software

HardwareHardwarePhysical Component of a Physical Component of a ComputerComputerWe can touch these partsWe can touch these partsAllow user to enter data Allow user to enter data and information into and information into computer and retrievecomputer and retrieveCan not perform any task Can not perform any task without Softwarewithout SoftwareIf problem occur in If problem occur in hardware then it will hardware then it will repaired.repaired.

SoftwareSoftwareLogical Component of a Logical Component of a ComputerComputerWe can not touch We can not touch These are in form of These are in form of instructions that tell the instructions that tell the computer that what to docomputer that what to doIt can not executed without It can not executed without hardware.hardware.If any problem in software If any problem in software then it will reinstall.then it will reinstall.

33

HardwareHardware

The The motherboardmotherboard is the main electronic is the main electronic component of the computercomponent of the computer Circuit boardCircuit board

The The microprocessormicroprocessor is one of the most is one of the most important pieces of processing hardware important pieces of processing hardware on the motherboardon the motherboard

CardsCards are removable circuit boards are removable circuit boards

44

Computer componentsComputer components

Logical units of a computerLogical units of a computer Input unitInput unit Output unitOutput unit Memory unitMemory unit Arithmetic and logic unit (ALU)Arithmetic and logic unit (ALU) Central processing unit (CPU)Central processing unit (CPU) Secondary storage unitSecondary storage unit

55

The Central Processing UnitThe Central Processing Unit

Central Processing Unit

Backing store

Output devices

Input devices Immediate access store

Control unit

Arithmetic & logic

unit

Data signals

Control signals

66

Working Working

Input Unit

CPUUnit

Ram / Rom

ALU & LogicalUnit

Control Unit

Output Unit

Storage Devices

77

Input & Output Input & Output

The data or instructions you type into the The data or instructions you type into the

computer are called computer are called inputinputThe result of the computer processing The result of the computer processing

your input is referred to as your input is referred to as outputoutputPeripheral devicesPeripheral devices accomplish input and accomplish input and output functionsoutput functions

88

Input DeviceInput Device

You use an You use an input deviceinput device, such as a keyboard or a , such as a keyboard or a mouse, to input data and issue commandsmouse, to input data and issue commands KeyboardKeyboard

ErgonomicErgonomic Pointing devicePointing device

Controls the pointerControls the pointerMouseMouse

Scroll wheelScroll wheel

TrackballTrackballTouch padTouch padPointing stickPointing stick

ScannerScanner

99

Output DevicesOutput Devices

Output devices Output devices show you the results of show you the results of processing dataprocessing data MonitorMonitor

Flat panelFlat panelLCDLCDCRTCRT

PrinterPrinterLaserLaserInkjetInkjetDot matrixDot matrix

1010

Memory UnitsMemory Units

Random Access Memory ( RAM ) Random Access Memory ( RAM )

Read Only Memory ( ROM ) Read Only Memory ( ROM )

1111

Backing StorageBacking Storage

Which consists of the disk drivers Which consists of the disk drivers used to store data when the power used to store data when the power is switched off.is switched off.Magnetic mediaMagnetic media

Hard diskHard disk TapeTape Floppy diskFloppy disk

Optical storage deviceOptical storage device CDCD DVDDVD CD-RCD-R CD-RWCD-RW CD-ROMCD-ROM

1212

Brain of Computer Brain of Computer Central Processing UnitCentral Processing Unit

CPU

Control Unit Arithmetic Unit Logical unit

1313

Control Unit Control Unit

Responsible for coordinating the input and Responsible for coordinating the input and output Devices.output Devices.

1414

Arithmetic Arithmetic

In which all the calculations are Involve.In which all the calculations are Involve.

Addition Addition

Subtraction Subtraction

Multiplications Multiplications

Divisions Divisions

Modulus Modulus

1515

Logical unit Logical unit

It contains the logical decisions It contains the logical decisions Greater thanGreater thanLess thanLess thanEqual toEqual toNot equal toNot equal toGreater than equal toGreater than equal toLess than equal toLess than equal toAnd operationsAnd operationsOr Operations Or Operations Not operations Not operations

1616

Why use Computer?Why use Computer?

AdvantagesAdvantages

Computers are extremely fast Computers are extremely fast

Computers are very accurateComputers are very accurate

Computers can keep large amount of Computers can keep large amount of information in a small spaceinformation in a small space

Computers can work continuously for 24 hours a Computers can work continuously for 24 hours a day.day.

Computers can do some jobs that would be Computers can do some jobs that would be impossible without them.impossible without them.

1717

DrawbacksDrawbacks

Computers can replace people Computers can replace people

Computers holds personal information Computers holds personal information which may be misused.which may be misused.

Problems arise when computers cannot be Problems arise when computers cannot be used.used.

Staff need to be trained Staff need to be trained

1818

Signal Signal

That pass between the main processor and That pass between the main processor and the other hardware.the other hardware.

Control SignalControl Signal : :

include signals sent out by the main include signals sent out by the main processor and the other hardware.processor and the other hardware.

Data Signals: Data Signals:

These are the groups of binary These are the groups of binary digits that are used to represent characters.digits that are used to represent characters.

1919

Types of computers by SizeTypes of computers by Size

Micro computersMicro computers

Mainframe Computers Mainframe Computers

Super ComputersSuper Computers

Mini ComputersMini Computers

Embedded ComputersEmbedded Computers

2020

Micro ComputersMicro Computers

Are the computers that you are most likely to Are the computers that you are most likely to encounter at home or in school and colleges.encounter at home or in school and colleges.

It consist of one or more input device ,output It consist of one or more input device ,output device, memory and processor.device, memory and processor.

ExamplesExamples

PCsPCs

Apples Apples

2121

Types of Micro ComputersTypes of Micro Computers

Desktop ComputersDesktop Computers

Laptop and notebook Laptop and notebook ComputersComputers

Personal Digital Assistants Personal Digital Assistants (PDA)(PDA)

Palmtop ComputersPalmtop Computers

2222

Mainframe computersMainframe computersThousands of terminals attached to it.Thousands of terminals attached to it.

Larger mainframe computers carry out Larger mainframe computers carry out 250 million instructions per second.250 million instructions per second.

It Consist of multiple processors.It Consist of multiple processors.

Used large organizations such as banks, Used large organizations such as banks, insurance companies, airlines and insurance companies, airlines and government department.government department.

Disadvantage:Disadvantage:

Due to immense power they produce Due to immense power they produce large amount of heat so its require air large amount of heat so its require air conditioned.conditioned.

2323

ExamplesExamples

IBM43810IBM43810

NEC610NEC610

DEC 10 etcDEC 10 etc

2424

SupercomputersSupercomputers

Largest category of computer, costing Largest category of computer, costing millions of pounds.millions of pounds.

It is complex, large storage and advanced It is complex, large storage and advanced computers.computers.

They are mostly used by scientific and They are mostly used by scientific and industrial research departments.industrial research departments.

2525

UsesUses

NASA NASA

Weather centreWeather centre

Stock ExchangeStock Exchange

Weapon design Weapon design

Mapping the surface of planets.Mapping the surface of planets.

Studying the neural network of brainStudying the neural network of brain

Preparing models of chemical systems.Preparing models of chemical systems.

2626

ExamplesExamples

CRAY-XPCRAY-XP

ETA-10 ETA-10

Blue sky Blue sky

ASCI WhiteASCI White

2727

Mini computersMini computers

Have a size , power and cost somewhere Have a size , power and cost somewhere between those of microcomputers and between those of microcomputers and mainframes.mainframes.

It is much powerful then some of the It is much powerful then some of the mainframes still in use.mainframes still in use.

It is used by business institutes and It is used by business institutes and departments.departments.

2828

ExamplesExamples

Vax-8800Vax-8800

MV-1500MV-1500

2929

Embedded Computers or Embedded Computers or MicroprocessorsMicroprocessors

Is a single chip that perform the functions of a Is a single chip that perform the functions of a central processing unitcentral processing unitMany microprocessors makes are Many microprocessors makes are Microcontrollers also called embedded.Microcontrollers also called embedded.Embedded computers serve as the brain of a Embedded computers serve as the brain of a larger piece of machine.larger piece of machine.Their software is stored in the computer’s own.Their software is stored in the computer’s own.They serve as a personal computer but not They serve as a personal computer but not have a monitor, keyboard and mousehave a monitor, keyboard and mouse

3030

UsesUses

Microwaves programmable ovens Microwaves programmable ovens Blood pressure monitorsBlood pressure monitorsAir bag sensors Air bag sensors Washing machinesWashing machinesVideo recordersVideo recordersAlarms Alarms Digital cameras Digital cameras MP3 playersMP3 playersCar engine ControllersCar engine Controllers

3131

Types of Computer by shapeTypes of Computer by shape

Types

Analog Digital Hybrid

3232

Analog computersAnalog computers

It provides continuous valueIt provides continuous value

It represents physical quantities in the It represents physical quantities in the form of wavesform of waves

It has no state It has no state

It has low memory It has low memory

It is difficult to useIt is difficult to use

It is used in engineering and scienceIt is used in engineering and science

3333

ExamplesExamples

ThermometerThermometer

Analog ClocksAnalog Clocks

Speed of the car Speed of the car

Petrol StationsPetrol Stations

3434

Digital computersDigital computers

It provides us discrete valuesIt provides us discrete values

It represent physical values with help of It represent physical values with help of symbols or numberssymbols or numbers

It has two states ON and OFFIt has two states ON and OFF

It has big memory It has big memory

These are easy to use These are easy to use

It is used in all field of life It is used in all field of life

3535

ExamplesExamples

Digital clocks Digital clocks

Calculators Calculators

Laptop computersLaptop computers

Score boardScore board

3636

Hybrid ComputersHybrid Computers

These are combination of analog and These are combination of analog and digital computersdigital computers

Some part of processing is done in digital Some part of processing is done in digital and some part is done in analog.and some part is done in analog.

The measurement may then be converted The measurement may then be converted into numbers and display in digital form.into numbers and display in digital form.

3737

ExamplesExamples

Patient Heart function Patient Heart function

Temperature Temperature

Blood pressureBlood pressure