Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Introduction to Information Technology
2nd EditionTurban, Rainer & Potter
© 2003 John Wiley & Sons, Inc.
Chapter 3:Computer Hardware
Prepared by:Roberta M. Roth, Ph.D.
University of Northern Iowa
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Chapter Preview
In this chapter, we will study:The hardware components of an
information system:• CPU (central processing unit)• Memory (primary and secondary storage)• Input devices• Output devices.
The classification of computers by power.
Strategic issues regarding hardware.
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The Central Processing Unit (CPU)
InputDevices
SecondaryStorage
OutputDevices
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
CommunicationDevices
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
A microprocessor that executes instructions to perform processing tasks. Component parts are:Control UnitArithmetic-Logic UnitRegistersPrimary Storage
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
Control UnitAccess program
instructions Decode (interpret)
instructionsControl flow of data
throughout systemData flows through
paths called buses
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
Arithmetic-Logic UnitPerform computations on data Perform comparisons on data
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
RegistersHigh speed storage areas Hold data and instructions
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
Primary Storage (Main Memory)Stores instructions from programsStores data to be processed
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
Machine Instruction CycleAn instruction is fetched from primary
storage by the Control UnitThe Control Unit decodes the
instructionThe ALU receives the data and the
instruction and performs the calculation or comparison
The result is stored in primary storage.
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)
Computer performance is measured in part by the number of Machine Instruction Cycles performed per second.
Factors affecting this performance include:Clock SpeedWord LengthBus WidthLine Width
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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The CPU (continued)Microprocessors evolved rapidly due to
Miniaturation of transistorsDecreasing distance between transistors on
the chip (decreasing line width)Improved conductivity (flow) of electricityImproved instruction sets programmed into
the chip.Smaller, faster, cheaper, more powerful
chips with each generation.
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Computer Memory
InputDevices
SecondaryStorage
OutputDevices
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
CommunicationDevices
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Computer Memory BasicsComputers are digital, and represent data
in bit patternsBit is shorthand for Binary digIT. The binary
system consists of two values: 0 & 18 bits = byteBytes are the basic measure of storage in
computersASCII Code assigns a unique character to
each pattern of 0s &1s in a byte.Kilobytes, Megabytes, Gigabytes, Terabytes
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Primary Storage (Main Memory)
Main memory is a temporary storage area that holds three things…information you are working withthe application software you are usingthe operating system software
Increasing memory capacity increases the performance of the system
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Primary Storage (Main Memory)
Types of Primary StorageRegisters – part of the CPU; very fast; very limited
capacityRandom Access Memory (RAM) – memory
chips on motherboard; general storage of program instructions and data; volatile
Cache Memory – faster than RAM; used to provide intermediate storage between secondary storage and RAM
Read-only Memory (ROM) – chips storing permanent instructions needed by computer; non-volatile
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Secondary Storage
Non-volatile storage of data and instructions
Huge storage capacityCheaper than Primary StorageSlower than Primary StorageMagnetic and optical storage
media
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Secondary Storage Types Magnetic tape
Cheap, slow, sequential access: good for backup Magnetic Disk
FloppyHard diskZip drive
Memory Cards and Cartridges Optical
CD-ROM, CD-RWDVD FMD-ROM
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Storage for the Enterprise
Enterprise Storage Systems – provide coordinated, secure, managed storage for all enterprise data.Redundant array of independent disks
(RAID)Storage area networkNetwork-attached storage
Storage Service Providers – third party storage utilities
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Computer Classifications
Computers are commonly classified by their processing power:SupercomputersMainframesMidrangeWorkstationsMicrocomputersComputing appliances
Classification boundaries are blurred.
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Computer Classifications
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Input Technology
InputDevices
SecondaryStorage
OutputDevices
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
CommunicationDevices
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Input Technologies
Human-orientedKeyboardMice / trackballTouch screensStylus JoystickMicrophone
AutomatedATMsPOSsOptical Scanners
• OMR• MICR• OCR
Voice recognitionSensorsCameras
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Output Technology
InputDevices
SecondaryStorage
OutputDevices
ControlUnit
PrimaryStorage
ALU
Registers
The CPU
CommunicationDevices
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Output Technologies
MonitorsPrintersVoiceMultimedia
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Strategic Hardware Issues Productivity
Will employees’ personal productivity increase as microprocessor power and speed increases?
Changing Work Styles Will new work styles will benefit employees and the
firm as a whole? New Products and Services
Is the organization ready and able to take advantage of the new products and services that hardware advances may make possible for the business?
Improved Communication Is the organization ready to use multimedia for
knowledge sharing?
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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Chapter Summary
Basic role and function of the CPUPrimary and secondary storageClassifications of computers based on
processing powerVariety and purpose of input devicesVariety and purpose of output devicesConsideration of strategic issues raised
by the advances in hardware technology
Introduction to Information Technology, 2nd EditionTurban, Rainer & Potter© 2003 John Wiley & Sons, Inc.
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