Computer harware

Computer HardwareComputer Hardware

Overview of Computer SystemsOverview of Computer Systems

ComputerComputer – device that performs stored – device that performs stored instructions.instructions.

ProgramProgram – instructions for computers to – instructions for computers to perform tasks.perform tasks.

Computer systemComputer system – consist of computers – consist of computers and other peripheral devices. and other peripheral devices.

HardwareHardware – physical components of a – physical components of a computer systemcomputer system

SoftwareSoftware - programs - programs

Basic Model of Computer SystemBasic Model of Computer System

CPU

RAM ROM

INPUT DEVICES

OUTPUT DEVICES

STORAGEDEVICES

ALUControl

Unit

Performance variables of ITPerformance variables of IT

Functional capabilitiesFunctional capabilities Ease of useEase of use CompatibilityCompatibility MaintainabilityMaintainability

Measuring functional capabilitiesMeasuring functional capabilities

Amounts of dataAmounts of data TimeTime Rate of data transferRate of data transfer Internal clock speed & transmission Internal clock speed & transmission

frequencyfrequency Speed of executing instructionsSpeed of executing instructions

Machine representation of dataMachine representation of data

On = 1On = 1

Off = 0Off = 0

Number systemsNumber systems

Decimal systemDecimal system Binary systemBinary system Hexadecimal systemHexadecimal system Octal systemOctal system

Coding data for computer Coding data for computer processingprocessing

Binary representation of numbersBinary representation of numbers• E.g. 7 = 111E.g. 7 = 111

Binary representation of textBinary representation of text• E.g. Letter “A” is 01000001E.g. Letter “A” is 01000001

Measuring amounts of dataMeasuring amounts of data

Bit - a binary digitBit - a binary digit Byte = 8 bits Byte = 8 bits Kilobyte = 1024 bytesKilobyte = 1024 bytes Megabyte = 1024 KilobytesMegabyte = 1024 Kilobytes Gigabyte = 1024 MegabytesGigabyte = 1024 Megabytes Terabyte = 1024 GigabytesTerabyte = 1024 Gigabytes

Measuring timeMeasuring time

Millisecond = 10Millisecond = 10-3-3 second second Microsecond = 10Microsecond = 10-6-6 second second Nanosecond = 10Nanosecond = 10-9-9 second second Picosecond = 10Picosecond = 10-12-12 second second

Measuring rate of data transferMeasuring rate of data transfer

Bps – Bit/secBps – Bit/sec Kbps – Kilobit/secKbps – Kilobit/sec Mbps – Megabit/secMbps – Megabit/sec Gbps – Gigabit/secGbps – Gigabit/sec

Measuring clock speedMeasuring clock speed

Hz – HertzHz – Hertz KHz – KilohertzKHz – Kilohertz MHz – MegahertzMHz – Megahertz GHz - GigahertzGHz - Gigahertz

Measuring speed of executing Measuring speed of executing instructionsinstructions

MIPS – Millions of instructions per MIPS – Millions of instructions per secondsecond

FLOPS – Floating point operations per FLOPS – Floating point operations per secondsecond

Ease of useEase of use

Related to size, weight, portability, Related to size, weight, portability, user interface, ergonomicsuser interface, ergonomics

CompatibilityCompatibility

Conformance to standardsConformance to standards Usability in combination or as Usability in combination or as

substitute to other similar substitute to other similar technologies.technologies.

InterchangeabilityInterchangeability

MaintainabilityMaintainability

Keeping the technology runningKeeping the technology running Related to modularityRelated to modularity Ease of upgradingEase of upgrading

Types of ComputersTypes of Computers

MainframeMainframe Midrange computerMidrange computer Personal computerPersonal computer

• Laptop/NotebookLaptop/Notebook• WorkstationWorkstation• ServersServers

Supercomputer Supercomputer Embedded computerEmbedded computer

Computer System ArchitectureComputer System Architecture

Centralized computingCentralized computing Distributed computingDistributed computing Personal computingPersonal computing Network computingNetwork computing Client-Server computingClient-Server computing

• Thick client vs. Thin clientThick client vs. Thin client

Centralized computingCentralized computing

Distributed computingDistributed computing

Personal computingPersonal computing

Network computingNetwork computing

Approaches for increasing Approaches for increasing computer performancecomputer performance

Faster and more powerful processorsFaster and more powerful processors Improved instruction setImproved instruction set Specialized processorsSpecialized processors Parallel processingParallel processing

Input DevicesInput Devices

Keyboards and pointing devicesKeyboards and pointing devices OCR / MICROCR / MICR Voice recognitionVoice recognition Digital cameraDigital camera

Storage DevicesStorage Devices

Paper and micrographicsPaper and micrographics Magnetic tapes and disksMagnetic tapes and disks Optical disksOptical disks Flash memoryFlash memory

Output DevicesOutput Devices

Screen outputsScreen outputs Paper outputsPaper outputs Audio outputsAudio outputs