Chapter 4 Hardware for Educators. System unit Boxlike case that houses the electronic components of...

Chapter 4Chapter 4

Hardware for Educators

• System unit• Boxlike case that

houses the electronic components of the computer that are used to process data

The System UnitThe System Unit

• Analog vs. Digital• Digital

• Two states• (1) on• (0) off

Data RepresentationData Representation

• Binary number system• Combination of ones and zeroes represent

characters


• ASCII

• American Standard Code for Information Interchange

• Converting a keyboard stroke into a byte


• The Motherboard

• Contains many of the electronic components

• Chip• A small piece of semiconducting

material on which one or more integrated circuits are etched

The Components of the System The Components of the System UnitUnit

• CPU and Microprocessor

• Interprets and carries out the basic instructions that operate a computer

• Microprocessor contains the CPU in a PC


• The Control Unit• A component of the CPU that directs and

coordinates most of the operations in the computer• Fetch - get the next instruction from memory• Decode - translate the instruction• Execute - carry out the command• Store the result - write the result to memory• Machine cycle


• The Arithmetic/Logic Unit

• Performs the execution part of the machine cycle

• Arithmetic (addition, subtraction, multiplication, division)

• Comparison (greater than, equal to, less than)

• Logical (AND, OR, NOT)


• The System Clock

• Synchronizes all computer operations

• Each tick is called a clock cycle

• Faster clock means more instructions the CPU can execute each second

• Speed measured in megahertz (MHz) and gigahertz (GHz)


• Memory• Used to store data, instructions, and

information• The operating system and other system software• Application programs• Data being processed by application programs

• Bytes are stored at specific locations or addresses


Seats in a stadium are similar to addresses in memory:

(1) A seat in memory holds one person at a time, and an address in memory holds a single byte

(2) Both a seat and an address can be empty

(3) A seat has a unique identifying number and so does an address

• Memory• Size of memory is measured by the number of

bytes available• Volatile memory – contents are lost when the

computer is powered down• Nonvolatile memory – contents are not lost

when the computer is powered down


• Random Access Memory (RAM)

• The memory chips in the system unit

• When the computer starts, operating system files are loaded from a hard disk into RAM

• Synchronous Dynamic RAM (SDRAM)

• Dual Inline Memory Module (DIMM)


• Random Access Memory (RAM)• RAM Chips

• Smaller in size than processor chips

• Packaged on circuit boards called single inline memory modules (SIMMs) or dual inline memory modules (DIMMs)


• Random Access Memory (RAM)

• Configuring RAM• The more RAM, the more programs and files

a computer can work on at once• Software usually tells you how much RAM

is required• Necessary RAM depends on what type of

work the computer is used for



• Read-Only Memory (ROM)

• Cannot be modified

• Contents not lost when the computer is turned off

• Flash Memory

• Type of nonvolatile memory that can be erased electronically and rewritten on

• Expansion Slots and Expansion Cards• Expansion slot

• An opening, or socket, where a circuit board can be inserted into the motherboard

• Add new devices or capabilities to the computer

• Expansion card• Circuit boards, such as a modem or graphics card,

that add new capabilities to the computer


• Expansion Slots and Expansion Cards

• Three common types• Video card• Sound card• Internal modem

• Plug and Play



• PC Card

• Thin credit card-sized device that adds capabilities to small computers

• Flash Memory Card

• Removable memory device that allows users to transfer data and information from a mobile device to a desktop computer

• Any data or instructions you enter into the memory of a computer• Data - unorganized facts• Programs - series of instructions that tells the

computer how to perform a task• Commands - an instruction given to a

computer program• User responses - responses to questions or

messages from the software

What is Input?What is Input?

What are Input Devices?What are Input Devices?

• Any hardware component that allows you to enter data, programs, commands, and user responses into a computer

• The Keyboard• Typing area• Numeric keypad• Toggle keys• Status lights• Arrow keys - arrow control keys• Function keys• Specialized buttons


• Pointing Devices

• An input device that allows you to control a pointer on the screen

• Block arrow• I-beam• Pointing hand




• Mouse• One or two button

mouse• Moving the mouse

pointer• Clicking• Dragging• Double-clicking• Optical mouse• Cordless mouse


• Touchpad and Pointing Stick• Touchpad – small, flat,

rectangular pointing device that is sensitive to pressure and motion

• Pointing Stick – pressure-sensitive pointing device shaped like a pencil eraser

• Pointing Devices• Trackball

• Like a mouse, but the ball is on top

• Often used on portable computers



• Joystick• Uses the movement of

a vertical lever• Often used with games

• Wheel• Steering-wheel type

input device• Used to simulate

driving a car


• Pointing Devices• Touch screen

• Monitor has a touch sensitive panel

• Used to issue simple commands or choose from a list of options

• Kiosks



• Optical Scanners

• Captures an entire page of text or images such as photographs or artwork electronically

• Converts the text or image on the original document into digital data that can be stored on a disk and processed by the computer

What are Input Devices?What are Input Devices?• Pen Input

• Users write, draw, and tap on a flat surface to enter input

• Stylus – small metal or plastic device that looks like a tiny ink pen but uses pressure instead of ink

• Digital pen – slightly larger than a stylus

• Digital Cameras• Allows you to take

pictures and store the photographed images digitally

• Download, or transfer, pictures to your computer


• Audio and Video Input• Audio input

• Entering music, speech, or sound effects• Sound card• Speech Recognition

• Computer’s capability of distinguishing spoken words


• Audio and Video Input

• Video input• Entering a full-motion recording into a

computer and storing the video on a hard disk or some other medium

• Video capture card


• Input Devices for PDAs, Smart Phones, and Tablet PCs• Stylus

• Voice Input

• Portable keyboard

• Scanner

• On-screen keyboard

• Digital camera


• Text• Graphics• Audio• Video

What is Output?What is Output?

• Any computer component capable of conveying information to the user

• Commonly used output devices• Monitors

• Printers

• Data Projectors

• Facsimile machines

• Multifunction devices

• Speakers

• Headsets

What are Output Devices?What are Output Devices?


• Monitors and Display Devices

• Screen housed in a plastic or metal case

• Variety of sizes

• Cathode ray tube (CRT)

• Pixels

• LCD (liquid crystal display) monitors

• Large Display Monitors

• Allow an audience or a group of students in a classroom to easily view images and multimedia displayed on a computer

• Available from 27 to 36 inches


• Large Display Monitors• High-definition

television (HDTV)• Gas plasma monitor


• Flat Panel Monitors and Displays

• Uses liquid crystal instead of a CRT

• Consume less than 1/3 the power of a CRT

• Thinner and lighter than a CRT



• Monitor Quality

• Resolution (sharpness and clarity)• Expressed as number of columns and rows

• 800 x 600• 1800 x 1440

• Dot pitch

• Refresh rate

• ENERGY STAR

• Printers

• An output device that produces text and graphics on a physical medium such as paper or transparency film

• Hard copy (printout)

• Portrait vs. landscape

• Printing requirements vary


• Nonimpact Printers• Do not strike paper• Much quieter• Ink-jet printers

• Spray tiny drops of ink onto the paper

• Both black-and-white and color


• Nonimpact Printers• Laser printers

• High-speed, high-quality nonimpact printer

• Very high quality resolution


• Data Projectors• Allows an audience

to view output• LCD projectors• Digital light

processing (DLP) projector


• Facsimile (Fax) Machine• Used to transmit

and receive an image of a document over a phone line

• Stand-alone• Fax modem


• Multifunction Devices• Can print, scan,

copy and fax• Less space• Lower cost than

separate units


• Audio Output• Produce music,

speech, or other sounds

• Speakers• Headsets


• The media on which data, instructions, and information are kept

• The devices that record and retrieve data, instructions, and information

• Like a filing cabinet

What is Storage?What is Storage?

Storage Media and DevicesStorage Media and Devices

• Magnetic Disk

• Uses magnetic patterns to store data, instructions, and information on the disk’s surface

• Formatting is the process of preparing a disk for reading and writing by organizing the disk into storage locations called tracks and sectors

• Floppy Disks

• Portable, inexpensive storage medium consisting of a thin circular flexible film enclosed in a square shaped plastic shell

• Several sizes• 8-inch• 5.25-inch• 3.5-inch


• Zip Disks• Capacities greater than

100 MB• Many uses

• Graphics, audio, or video

• Transporting files• Backups

• Being replaced with USB flash drives and other portable storage devices


• Hard Disks• Provide large storage capacity and high

speed data access• Sizes range from 40 GB to 300 GB• Consists of several inflexible, circular

disks, called platters• Magnetic storage device• Formatting


• Miniature and Portable Hard Disks

• Miniature hard disks are found in consumer electronics and have greater storage capacities than flash memory

• External hard disks connect to a USB or FireWire port by a cable


• CDs and DVDs

• Optical storage media

• Used to distribute software

• Laser reads pits on the surface

• Used on multimedia computers

• Several types

• CD-ROM

• DVD-ROM


• Care of CDs and DVDs• Can last from 5 to 100 years if properly cared

for• Never bend a disc• Avoid extreme temperatures and humidity• Keep away from contaminants• Do not stack or touch discs• Use a protective case


• CD-ROM• Compact disc read-

only memory• Can contain text,

graphics, video, as well as sound

• Can hold 650 MB of data

• Used for today’s complex software


• CD-R and CD-RW

• Compact disc-recordable• Can write on each part of the disc only one

time• Cannot be erased

• Compact disc-rewriteable• Can write on multiple times• Erasable disc


• DVD-ROM and DVD+RW• Digital video disc read-only memory (DVD-ROM)

• Can store from 4.7 GB to 17 GB• High quality• DVD-ROM drives• May replace CDs, VCRs, and VHS tapes

• Digital video disc+rewritable (DVD+RW)• Can write on multiple times• Erasable disc


• Miniature Mobile Storage Media


Chapter SummaryChapter Summary

• Describe the system unit• Define the term bit and describe how a series of bits

are used to represent data• Identify the major components of the system unit

and explain their functions• Explain how the CPU uses the four steps of a

machine cycle to process data• Describe the four types of input as well as input

devices


• List the characteristics of a keyboard and identify various types of keyboards

• Identify various types of pointing devices• Differentiate among the four types of output• Identify the different types of output devices• Explain differences among various types of

printers


• Differentiate between storage and memory• Identify types of storage media and devices• Explain how data is stored on 3.5-inch

disks, hard disks, CD-ROMs, and DVDs• Differentiate between CD-ROMs and DVD-

ROMs

Chapter 4 CompleteChapter 4 CompleteChapter 4 CompleteChapter 4 Complete

Hardware for Educators

Buyer’s GuideBuyer’s GuideHOW TO PURCHASE

A PERSONAL COMPUTER

How to Purchase How to Purchase a Personal Computera Personal Computer

• Do you want a desktop computer, mobile computer, or personal mobile device?

• For what purposes will you use the computer?

• Should the computer be compatible with the computers at school or work?

• Should the computer be a Mac or PC?

How to Purchase How to Purchase a Desktop Computera Desktop Computer

• Determine the specific software you want to use on your computer

• Look for bundled software• Avoid buying the least powerful computer available• Consider upgrades to the mouse, keyboard, monitor,

printer, microphone, and speakers• Determine whether you want to use telephone lines or

broadband (cable or DSL) to access the Internet


• If you are using a dial-up or wireless connection to connect to the Internet, select an ISP or OSP

• Use a worksheet to compare computers, services, and other considerations

• If you are buying a new computer, you have several purchasing options: buying from your school bookstore, a local computer dealer, a local large retail store, or ordering by mail via telephone or the Web

• If you are buying a used computer, stay with name brands such as Dell, Gateway, Hewlett-Packard, and Apple

• If you have a computer and are upgrading to a new one, then consider selling or trading in the old one


• Be aware of hidden costs• Consider more than just price• Avoid restocking fees• Use a credit card to purchase your new

computer• Consider purchasing an extended warranty

or service plan

How to PurchaseHow to Purchasea Notebook Computera Notebook Computer

• Purchase a notebook computer with a sufficiently large active-matrix screen

• Experiment with different keyboards and pointing devices

• Make sure the notebook computer you purchase has a CD and/or DVD drive

• If necessary, upgrade the processor, memory, and disk storage at the time of purchase

• The availability of built-in ports on a notebook computer is important


• If you plan to use your notebook computer for note-taking at school or in meetings, consider a notebook computer that converts to a Tablet PC

• Consider purchasing a notebook computer with a built-in wireless card to connect to your home network

• If you are going to use your notebook computer for long periods without access to an electrical outlet, purchase a second battery

• Purchase a well-padded and well-designed carrying case


• If you travel overseas, obtain a set of electrical and telephone adapters

• If you plan to connect your notebook computer to a video projector, make sure the notebook computer is compatible with the video projector

• For improved security, consider a fingerprint scanner

How to Purchase a Tablet PCHow to Purchase a Tablet PC

• Make sure the Tablet PC fits your mobile computing needs

• Decide whether you want a convertible or pure Tablet PC

• Be sure the weight and dimensions are conducive to portability

• Port availability, battery life, and durability are even more important with a Tablet PC than they are with a notebook computer


• Experiment with different models of the Tablet PC to find the digital pen that works best for you

• Check out the comfort level of handwriting in different positions

• Make sure the LCD display device has a resolution high enough to take advantage of Microsoft’s ClearType technologies

• Test the built-in Tablet PC microphone and speakers


• Consider a Tablet PC with a built-in PC video camera

• Review the docking capabilities of the Tablet PC

• Wireless access to the Internet and your e-mail is essential with a Tablet PC

• Review available accessories to purchase with your Tablet PC

How to Purchase How to Purchase a Personal Mobile Devicea Personal Mobile Device

• Determine the programs you plan to run on your device

• Consider how much you want to pay• Determine whether you need wireless access

to the Internet and e-mail or mobile telephone capabilities with your device

• For wireless devices, determine how and where you will use the service

• Make sure your device has enough memory


• Practice with the touch screen, handwriting recognition, and built-in keyboard before deciding on a model

• Decide whether you want a color display• Compare battery life• Seriously consider the importance of

ergonomics


• Check out the accessories• Decide whether you want additional

functionality• Determine whether synchronization of data

with other Devices or personal computers is important

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