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Chapter 6Storage41 slides

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Chapter 6 Objectives

Describe the characteristics ofmagnetic disks

Describe the characteristics ofmagnetic disks

Describe the characteristics of a hard disk

Describe the characteristics of a hard disk

Differentiate between floppy disks and Zip disks

Differentiate between floppy disks and Zip disks

Describe the characteristics of optical disks

Describe the characteristics of optical disks

Differentiate among various CD and DVD formats

Differentiate among various CD and DVD formats

Identify the uses of tapeIdentify the uses of tape

Discuss PC Cards and the various typesof miniature mobile storage media

Discuss PC Cards and the various typesof miniature mobile storage media

Identify uses of microfilm and microfiche

Identify uses of microfilm and microfiche

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Storage

What is storage?

p. 220 - 221 Fig. 6-1 Next

Holds data, instructions, and information for future use Storage medium is physical material used for storage

Also called secondary storage

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Storage

What is capacity?

p. 222 Next

Kilobyte (KB) 1 thousand

Megabyte (MB) 1 million

Gigabyte (GB) 1 billion

Terabyte (TB) 1 trillion

Petabyte (PB) 1 quadrillion

Number of bytes (characters) a storage medium can hold

Exabyte (EB) 1 quintillion

Zettabyte (ZB) 1 sextillion

Yottabyte (YB) 1 septillion

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WritingWritingProcess of transferring Process of transferring

items from memory items from memory to storage mediato storage media

WritingWritingProcess of transferring Process of transferring

items from memory items from memory to storage mediato storage media

Storage

What is a storage device?

p. 222

ReadingReadingProcess of transferring Process of transferring

items from storage items from storage media to memorymedia to memory

ReadingReadingProcess of transferring Process of transferring

items from storage items from storage media to memorymedia to memory

Hardware that Hardware that records and records and

retrieves items retrieves items to and from to and from

storage mediastorage media

Functions as source of input

Creates output

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Storage

What is access time?

p. 222

Time it takes storage device to locate item on storage medium

Time required to deliver item from memory to processor

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Magnetic Disks

p. 222 Fig. 6-3 Next

What are tracks and sectors?

Formatting prepares disk for use and marks bad sectors as unusable

Trackis narrow

recording bandthat forms fullcircle on disk

Sector stores up to512 bytes

of data

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Perpendicular recording

Magnetic Disks

What is a hard disk?

p. 223 Fig. 6-4 Next

hard disk installedin system unit

High-capacity storage Consists of several

inflexible, circular platters that store items electronically

Components enclosed in airtight, sealed case for protection

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Perpendicular Recording below Chapter 6

Longitudinal recording

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Magnetic Disks

What are characteristics of a hard disk?

p. 224 Fig. 6-5 Next

Sample Hard Disk Characteristics

Advertised capacity 120 GB

Platters 3

Read/write heads 6

Cylinders 16,383

Bytes per second 512

Sectors per track 63

Sectors per drive 234,441,648

Revolutions per minute 7,200

Transfer rate 133 MB per second

Access time 8.9 ms

actualdisk

capacity

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Magnetic Disks

How does a hard disk work?

p. 224 Fig. 6-6 Next

Step 1.Circuit board controls movement of head actuator and a small motor.

Step 2.Small motor spins platters while computer is running.

Step 3.When software requests a disk access, read/write heads determine current or new location of data.

Step 4.Head actuator positions read/write head arms over correct location on platters to read or write data.

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Video: Install a New Hard Drive

Speed up your computer with a new hard drive

low quality(click to start)

high quality(click to start)

Next

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Magnetic Disks

What is a cylinder?

p. 225 Fig. 6-7 Next

Vertical section of track through all platters

Single movement of read/write head arms accesses all plattersin cylinder

platter

read/writehead

platter

sides

cylinder

track

sector

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Magnetic Disks

What is a head crash?

p. 225 Fig. 6-8 Next

clearance

read/write head

platter

hair

dustsmoke

Spinning creates cushion of air that floats read/write head above platter

Occurs when read/write head touches platter surface

A smoke particle, dust particle, or human hair could render drive unusable

Clearance between head and platter is approximately two-millionths of an inch

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Magnetic Disks

What is a miniature hard disk?

p. 226 Fig. 6-9

Provide users with greater storage capacities than flash memory Some have a form factor of less than 1 inch Storage capacities range from 2 GB to 120 GB

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Miniature Hard Disksbelow Chapter 6

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Magnetic Disks

What are external hard disks and removable hard disks?

p. 226 Fig. 6-10 Next

External hard disk—freestandinghard disk that connects to system unit

Removable hard disk—hard diskthat you insert and removefrom hard disk drive

Used to back up or transfer files

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SCSISCSI((SSmallmall CComputeromputer SSystemystem IInterface)nterface)

controller supports up to fifteencontroller supports up to fifteendevices including hard disks, CDdevices including hard disks, CD

and DVD drives, tape drives, printers,and DVD drives, tape drives, printers,scanners, network cardsscanners, network cards

SATASATA (Serial Advanced Serial Advanced Technology AttachmentTechnology Attachment) controller ) controller

uses serial signals to transfer data, uses serial signals to transfer data, instructions, and informationinstructions, and information

Magnetic Disks

What is a disk controller?

p. 226 - 227 Next

EIDEEIDE (EEnhancednhanced IIntegratedntegrated DDrive rive EElectronics) controller supports four lectronics) controller supports four hard disks, provides connections for hard disks, provides connections for

CD and DVD drivesCD and DVD drives

Chip and circuits that Chip and circuits that control transfer of control transfer of items from diskitems from disk

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Magnetic Disks

What is online storage?

p. 227 Fig. 6-11 Next

Others can be authorized to access your data

Service on Web that provides storage for minimal monthly fee

Files can be accessed from any computer with Web access

Large files can be downloaded instantaneously

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Online Storagebelow Chapter 6

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Magnetic Disks

What is a floppy disk?

p. 228

Portable, inexpensive storage medium (also called diskette)

Thin, circular, flexible film enclosedin 3.5” wide plastic shell

shutter

shell

liner

magneticcoating

flexible thin film

metal hub

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Magnetic Disks

What is a floppy disk drive?

p. 228 Fig. 6-12 Next

Floppy disk drive built intoa desktop computer

External floppy disk drive attaches to a computer with a cable

Also called secondary storage

One floppy drive, named drive A

Device that reads from andwrites to floppy disk

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Magnetic Disks

What is a Zip disk?

p. 228 Fig. 6-13 Next

Magnetic medium that stores 100 MB to 750 MB of data

Zip disks require a Zip drivec—chigh capacity drive that reads from and writes on a Zip disk

Used to back up and to transfer files Backup is duplicate of file, program, or disk

in case original is lostc

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Push the same buttonto close the tray.

Optical Discs

What are optical discs?

p. 229 Fig. 6-14 Next

Most PCs include an optical disc drive

Flat, round, portable metal discs made of metal, plastic, and lacquer

Can be read only or read/write

Insert the disc,label side up.

Push the button toslide out the tray.

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Optical Discs

How should you care for an optical disc?

p. 230 Fig. 6-15 Next

Do store thedisc in a jewelbox whennot in use

Do hold a discby its edges

Do noteat, smoke, ordrink neara disc

Do not stack discs

Do not exposethe disc to excessiveheat or sunlight

Do not touchthe undersideof the disc

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Optical Discs

What is a CD-ROM?

p. 231 Fig. 6-17 Next

Compact disc read-only memory

Cannot erase or modify contents Typically holds 650 MB to 1 GB Commonly used to distribute multimedia and complex software

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click CD-ROMsbelow Chapter 6

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Optical Discs

What is a Picture CD?

p. 232 Fig. 6-18 Next

Film developers offer

Picture CD service

Can be modified

using photo editing software

Stores digital versions of roll of film

Step 3.At home, print images from Picture CD on your ink-jet photo printer.

At a store, print images to Picture CD at kiosk.

Step 1.Drop off film to be developed. Mark the Picture CD box on the film-processing envelope.

Step 2.When you pick up prints and negatives, a Picture CD contains digital images of each photograph.

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Picture CDs below Chapter 6

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Optical Discs

What are CD-Rs and CD-RWs?

p. 232 Next

Must haveCD recorder

or CD-R drive

Cannot erasedisc’s contents

CD-R (compact disc-recordable)—cdisc you can write on once

CD-RW (compact disc-rewritable)—ceerasable disc you can write on

multiple times

Must haveCD-RW softwareand CD-RW drive

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Optical Discs

What is a DVD-ROM (digital versatile disc-ROM or digital video disc-ROM)?

p. 233 Fig. 6-19 Next

Must have DVD-ROM drive or DVD player to read DVD-ROM

Stores databases, music, complex software, and movies

Blu-ray discs have storage capacity of up to 27 GB

HD-DVD discs have storage capacity of up to 45 GB

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Optical Discs

How does a DVD-ROM store data?

p. 233 Fig. 6-20 Next

Two layers of pits are used, lower layer is semitransparent so laser can read through

Some are double-sided Many types of recordable and rewritable DVDs are

available DVD-R and DVD+R DVD-RW and DVD+RW

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click DVDsbelow Chapter 6

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Tape

What is tape?

p. 234 Fig. 6-21 Next

Magnetically coated plastic ribboncapable of storing large amountsof data at low cost

Primarily used for backup

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Tape

How is data stored on a tape?

p. 234 - 235 Next

Sequential access

Unlike direct access — used on floppy disks, Zip disks, hard disks, CDs, and DVDs — which can locate particular item immediately

Reads and writes data consecutively, like music tape

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PC Cards

What is a PC Card?

p. 235 Figs. 6-22–6-23 Next

Adds capabilities to computer Credit-card-sized device

commonly used in notebook computers

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Miniature Mobile Storage Media

What is miniature mobile storage media?

p. 236 Fig. 6-24 Next

Storage for small mobile devices

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Flash Memory Cardsbelow Chapter 6

CompactFlash Smart Media Secure Digital

Memory Stick xD Picture Card

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Miniature Mobile Storage Media

What is a USB Flash Drive?

p. 236 Fig. 6-25 Next

Plugs in a USB port on a computer or mobile device

Storage capacities up to 4 GB Making the floppy disk

obsolete

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Miniature Mobile Storage Media

What is a smart card?

p. 237 Fig. 6-26 Next

Stores data on microprocessor embedded in small card

Input, process, output, and storage capabilities

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Smart Cardsbelow Chapter 6

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Microfilm and Microfiche

What are microfilm and microfiche?

p. 238 Fig. 6-27 Next

Images recorded using Images recorded using computer output microfilm computer output microfilm

recorderrecorder

Store microscopic images of Store microscopic images of documents on roll or sheet of documents on roll or sheet of

filmfilm

Microfilm — 100- to215-foot roll of film

Microfiche — small sheet of film, usually 4” 6”

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Microfilm and Microfiche

How do life expectancies of various media compare?

p. 238 Fig. 6-28 Next

Microfilm and microfiche have longest life of any storage media

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Putting It All Together

What are recommended storage devices for home users?

p. 239 Fig. 6-29 Next

160 GB hard disk Online storage CD or DVD drive Card reader/writer USB flash drive

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Putting It All Together

What are recommended storage devices for small office/home office (SOHO) users?

p. 239 Fig. 6-29 Next

250 GB hard disk Online storage CD or DVD drive External hard drive for backup USB flash drive

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Putting It All Together

What are recommended storage devices for mobile users?

p. 239 Fig. 6-29 Next

100 GB hard disk Online storage CD or DVD drive Card reader/writer Portable hard disk for backup USB flash drive, and/or 5 GB PC Card hard

disk

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Putting It All Together

What are recommended storage devices for power users?

p. 239 Fig. 6-29 Next

CD or DVD drive 500 GB hard disk Online storage Portable hard disk for backup USB flash drive

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Putting It All Together

What are recommended storage devices for large business users?

p. 239 Fig. 6-29 Next

Desktop computer250 GB hard diskCD or DVD driveSmart card readerTape driveUSB flash drive

Server or MainframeNetwork storage server40 TB hard disk systemCD-ROM or DVD-ROM serverMicrofilm or microfiche

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Summary of Storage

Internal hard disksInternal hard disks

Portable hard disksPortable hard disks

Floppy disksFloppy disks

Zip disksZip disks

CD-ROMsCD-ROMs

Recordable and rewritable CDsRecordable and rewritable CDs

DVD-ROMsDVD-ROMs

Recordable and rewritable DVDsRecordable and rewritable DVDs

TapeTape

PC CardsPC Cards

Flash memory cardsFlash memory cards

USB Flash DrivesUSB Flash Drives

Microfilm and microficheMicrofilm and microfiche

Chapter 6 Complete

Smart CardsSmart Cards