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Computer Hardware

Chapter

3Chapter

3

3 - 2Copyright © 2006, The McGraw-Hill Companies, Inc. All rights reserved.

1. Identify the major types and uses of microcomputer, midrange, and mainframe computer systems.

2. Outline the major technologies and uses of computer peripherals for input, output, and storage.

Learning ObjectivesLearning Objectives

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What is a Computer?What is a Computer?

Definition:• All computers are systems of input,

processing, output, storage, and control components.

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Types of Computer SystemsTypes of Computer Systems

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Hardware Organized by System FunctionsHardware Organized by System Functions

• Input Devices convert data into electronic form for direct entry or through a telecommunications network into a computer system

• Processing Components primarily the Central Processing Unit (CPU)• Arithmetic-Logic Unit (ALU) - perform

arithmetic and logic functions on “registers” to execute software instructions

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Hardware Organized by System FunctionsHardware Organized by System Functions

• Output Devices convert electronic information produced by the computer system into human-intelligible form for presentation to end users

• Storage Devices store data and software instructions needed for processing

• Control Components primarily the CPU’s Control Unit which interprets software instructions and transmits directions that control the activities of the other components of the computer system

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Computer Processing SpeedsComputer Processing Speeds

• Millisecond – thousandth of a second

• Microsecond – millionth of a second

• Nanosecond – billionth of a second

• Picosecond – trillionth of a second

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Computer Clock SpeedsComputer Clock Speeds

• MIPS – million instructions per second

• Megahertz (MHz) – millions of cycles per second

• Gigahertz (GHz) – billions of cycles per second

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ThroughputThroughput

Definition:• Ability of a microprocessor to perform useful

computation or data processing assignments during a given period of time

Depends on:• Buses – size of circuitry paths that interconnect

microprocessor components• Registers – that process instructions• Cache – high-speed memory• Specialized Processors

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Computer PeripheralsComputer Peripherals

Definition:• Generic name given to all input, output,

and secondary storage devices that are part of a computer system, but are not part of the CPU.

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Peripherals AdvicePeripherals Advice

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Input TechnologiesInput Technologies

• Keyboard• Pointing Devices• Pen-Based Computing• Speech Recognition Systems• Optical Scanning• Magnetic cards (Buzzcards)

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Graphical User Interface (GUI)Graphical User Interface (GUI)

Definition:• Icons, menus, windows, buttons, bars, etc

used for user selection

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Output TechnologiesOutput Technologies

• Video Output (Monitor)• CRT• LCD

• Printed Output• Ink Jet• LaserJet

• Voice Response (GPS)

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Storage Trade-OffsStorage Trade-Offs

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Binary RepresentationBinary Representation

Definition:• Data are processed and stored in a

computer system through the presence or absence of electronic or magnetic signals in the computer’s circuitry or in the media it uses

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Bit vs. ByteBit vs. Byte

• Bit – binary digit, which can have a value of either zero or one

• Byte – basic grouping of bits that the computer operates as a single unit, typically eight bits

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Storage CapacitiesStorage Capacities

• Kilobyte (KB) – one thousand bytes• Megabytes (MB) – one million bytes• Gigabytes (GB) – one billion bytes• Terabytes (TB) – one trillion bytes• Petabytes (PB) – one quadrillion bytes

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RAM vs. ROMRAM vs. ROM

• Random Access Memory (RAM) – each memory position can be both sensed and changed

• Read Only Memory (ROM) – can be read but not erased or overwritten. Firmware.

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Computer Software

Chapter

4Chapter

4

3 - 21Copyright © 2006, The McGraw-Hill Companies, Inc. All rights reserved.

1. Understand the major types of application and system software.

2. Outline the functions of an operating system.

3. Describe the main uses of computer programming software, tools, and languages.

Learning ObjectivesLearning Objectives

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What is Software?What is Software?

Definition:• Various kinds of programs (instructions)

used to operate computers and related devices

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Types of SoftwareTypes of Software

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How is Software Developed?How is Software Developed?

• Custom Software – software applications that are developed within an organization for use by that organization

• Commercial Off-the-shelf (COTS) Software – software that is developed by a software developer with the intention of selling the software in multiple copies

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Web BrowserWeb Browser

Definition:• Software interface used to point and click

through the hyperlinked resources of the Internet

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Electronic Mail & Instant MessagingElectronic Mail & Instant Messaging

• Electronic Mail – software used to send and receive electronic messages and file attachments via the Internet, intranets or extranets

• Instant Messaging (IM) – software used to send and receive electronic messages instantly to facilitate real time communication and collaboration

3 - 27Copyright © 2006, The McGraw-Hill Companies, Inc. All rights reserved.

Word Processing & Desktop PublishingWord Processing & Desktop Publishing

• Word Processing – software that supports the creation, editing, revision and printing of documents

• Desktop Publishing (DTP) – software that supports the production of materials that look professionally published

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Electronic SpreadsheetsElectronic Spreadsheets

Definition:• Software that supports the development

of electronic worksheets consisting of rows and columns used for business analysis, planning and modeling

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Presentation GraphicsPresentation Graphics

Definition:• Software that helps convert numeric data

into graphics displays and prepare multimedia presentations including graphics, photos, animation, and video clips

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Personal Information Manager (PIM)Personal Information Manager (PIM)

Definition:• Software for end user productivity and

collaboration

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GroupwareGroupware

Definition:• Software that helps workgroups and

teams work together to accomplish group assignments

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Software AlternativesSoftware Alternatives

• Purchase Commercial Off-The-Shelf (COTS) software

• Application Service Providers –companies that own, operate, and maintain application software and the computer system resources required to offer the use of the application software for a fee as a service over the Internet

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System SoftwareSystem Software

• System Management Programs – programs that manage the hardware, software, network, and data resources of computer systems during the execution of various information processing jobs of end users (Windows XP)

• System Development Programs – programs that help users develop information system programs and procedures and prepare user programs for computer processing (Visual Basic)

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Operating SystemOperating System

Definition:• An integrated system of programs that

manages the operations of the CPU, controls the input/output and storage resources and activities of the computer system, and provides various support services as the computer executes the application programs of users

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Operating System FunctionsOperating System Functions

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User InterfaceUser Interface

Definition:• The part of the operating system that

allows you to communicate with it so you can load programs, access files, and accomplish other tasks• Command-Driven• Menu-Driven• Graphical User Interfaces

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Programming LanguagesProgramming Languages

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Web LanguagesWeb Languages

• HTML – a page description language that creates hypertext or hypermedia documents

• XML – describes the contents of Web pages by applying identifying tags or contextual labels to the data in Web documents

• Java – an object-oriented programming language that is simple, secure and platform independent