Ch03

Introduction to Information Technology 2nd Edition Turban, 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 Edition Turban, 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 Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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The Central Processing Unit (CPU) The CPU Input Devices

Control ALU Unit

Registers Primary Storage

Output Devices

Communication Devices

Secondary Storage

Introduction to Information Technology, 2nd Edition Turban, 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 Unit Arithmetic-Logic Unit Registers Primary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

The CPU Control ALU Unit

Registers Primary Storage

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The CPU (continued) Control Unit Access program instructions Decode (interpret) instructions Control flow of data throughout system Data flows through paths called buses Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

The CPU Control ALU Unit

Registers Primary Storage

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The CPU (continued) Arithmetic-Logic Unit Perform computations on data Perform comparisons on data The CPU Control ALU Unit

Registers Primary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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The CPU (continued) Registers High speed storage areas Hold data and instructions The CPU Control ALU Unit

Registers Primary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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The CPU (continued) Primary Storage (Main Memory) Stores instructions from programs Stores data to be processed The CPU Control ALU Unit

Registers Primary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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The CPU (continued) Machine Instruction Cycle An instruction is fetched from primary storage by the Control Unit The Control Unit decodes the instruction The 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 Edition Turban, 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 Speed  Word Length  Bus Width  Line Width Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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The CPU (continued) Microprocessors evolved rapidly

due to

Miniaturation of transistors Decreasing distance between transistors on the chip (decreasing line width) Improved conductivity (flow) of electricity Improved instruction sets programmed into the chip.

Smaller, faster, cheaper, more Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

powerful chips with each

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Computer Memory The CPU Input Devices

Control ALU Unit

Registers Primary Storage

Output Devices

Communication Devices

Secondary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Computer Memory Basics  Computers are digital, and represent

data in bit patterns  Bit is shorthand for Binary digIT. The binary system consists of two values: 0 &1  8 bits = byte  Bytes are the basic measure of storage in computers  ASCII Code assigns a unique character to each pattern of 0s &1s in a byte.  Kilobytes, Megabytes, Gigabytes, Terabytes Introduction to Information Technology, 2nd Edition Turban, 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 with the application software you are using the operating system software

Increasing memory capacity

increases the performance of the system

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Primary Storage (Main Memory)  Types of Primary Storage  Registers – part of the CPU; very fast; very limited capacity

 Random 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; nonvolatile Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Secondary Storage Non-volatile storage of data and

instructions Huge storage capacity Cheaper than Primary Storage Slower than Primary Storage Magnetic and optical storage media Introduction to Information Technology, 2nd Edition Turban, 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

 Floppy  Hard disk  Zip drive  Memory Cards and Cartridges  Optical  CD-ROM, CD-RW  DVD  FMD-ROM Introduction to Information Technology, 2nd Edition Turban, 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 network Network-attached storage Storage Service Providers – third party storage utilities Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Computer Classifications  Computers are commonly classified by

their processing power:  Supercomputers  Mainframes  Midrange  Workstations  Microcomputers  Computing appliances

 Classification boundaries are blurred. Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Computer Classifications

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Input Technology The CPU Input Devices

Control ALU Unit

Registers Primary Storage

Output Devices

Communication Devices

Secondary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Input Technologies  Human-oriented  Keyboard  Mice / trackball  Touch screens  Stylus  Joystick  Microphone

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

 Automated  ATMs  POSs  Optical Scanners • OMR • MICR • OCR

 Voice recognition  Sensors  Cameras 3-22

Output Technology The CPU Input Devices

Control ALU Unit

Registers Primary Storage

Output Devices

Communication Devices

Secondary Storage

Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Output Technologies  Monitors  Printers  Voice  Multimedia

Introduction to Information Technology, 2nd Edition Turban, 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 Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Chapter Summary  Basic role and function of the CPU  Primary and secondary storage  Classifications of computers based on

processing power  Variety and purpose of input devices  Variety and purpose of output devices  Consideration of strategic issues raised by the advances in hardware technology Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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Introduction to Information Technology, 2nd Edition Turban, Rainer & Potter © 2003 John Wiley & Sons, Inc.

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