Discovering Computers

FundamentalsFifth Edition

Chapter 6Storage

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

Discuss various types of miniature, external, and removable hard disksDiscuss various types of miniature, external, and removable hard 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, ExpressCard modules and the various types

of miniature mobile storage media

Discuss PC Cards, ExpressCard modules and the various types

of miniature mobile storage media

Identify uses of microfilm and microfiche

Identify uses of microfilm and microfiche

Next

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

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

WritingProcess of transferring

items from memory to storage media

WritingProcess of transferring

items from memory to storage media

Storage

What is a storage device?

p. 222 Next

ReadingProcess of transferring

items from storage media to memory

ReadingProcess of transferring

items from storage media to memory

Hardware that records and

retrieves items to and from

storage media

Functions as source of input

Creates output

Storage

What is access time?

p. 222

Time it takes storage device to locate item on storage medium

Next

Time required to deliver item from memory to processor

Magnetic Disks

p. 222 Fig. 6-3 Next

What are tracks and sectors?

Formatting prepares disk for use

Trackis narrow

recording bandthat forms fullcircle on disk

Sector stores up to512 bytes

of data

Perpendicular recording

Magnetic Disks

What is a hard disk?

p. 223 Fig. 6-4 Next

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

Magnetic Disks

What are characteristics of a hard disk?

p. 224 Fig. 6-5 Next

Sample Hard Disk Characteristics

Advertised capacity 500 GB

Platters 4

Read/write heads 8

Cylinders 16,383

Bytes per second 512

Sectors per track 63

Sectors per drive 973,773,168

Revolutions per minute 7,200

Transfer rate 300 MB p/sec

Access time 8.5 ms

actualdisk

capacity

Magnetic Disks

How does a hard disk work?

p. 224 Fig. 6-6 Next

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

Magnetic Disks

What is a head crash?

p. 225 Fig. 6-8 Next

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

Next

Magnetic Disks

What is RAID?

p. 226

Redundant Array of Independent Disks Connects multiple smaller disks into a single unit that

acts as a single large hard disk

Next

Magnetic Disks

What is a miniature hard disk?

p. 226 Fig. 6-9 and 6-10

Provide greater storage capacities than flash memory Smaller than notebook computer hard disks A pocket hard drive is a self-contained unit

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

Magnetic Disks

What are external hard disks and removable hard disks?

p. 226 Fig. 6-11 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

Magnetic Disks

What is a disk controller?

p. 227 Next

SAScontroller supports many connected

devices at once, including hard disks,CD and DVD drives, printers,

scanners, digital cameras, and more

EIDE (Enhanced Integrated Drive Electronics) controller supports four hard disks, provides connections for

CD and DVD drives

SCSIcontroller supports up to fifteen

devices including hard disks, CDand DVD drives, tape drives,

printers, scanners, network cards

SATA (Serial Advanced Technology Attachment)

controller uses serial signals to transfer data, instructions, and

information

Chip and circuits that control transfer of items from disk

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

Magnetic Disks

What is online storage?

p. 228 Fig. 6-12 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

Magnetic Disks

What is a floppy disk?

p. 228 Next

Portable, inexpensive storage medium (also called diskette)

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

Magnetic Disks

What is a floppy disk drive?

p. 228 Fig. 6-13 Next

External floppy disk drive attaches to a computer with a cable

Also called secondary storage

Device that reads from andwrites to floppy disk

Push the same button to 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.

Push the button toslide out the tray.

Optical Discs

How should you care for an optical disc?

p. 230 Fig. 6-15 Next

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 Link from left navigation, then click CD-ROMsbelow Chapter 6

Optical Discs

What is an Archive CD?

p. 232 Fig. 6-18 Next

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

Optical Discs

What are CD-Rs and CD-RWs?

p. 232 - 233 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

Optical Discs

Video: Got Your Video Right Here

Next

CLICK TO START

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 100 GB

HD-DVD discs have storage capacity of up to 60 GB

HD-VMDs have storage capacity of up to 40 GB or more

UMD can store up to 1.8 GB

Optical Discs

How does a DVD-ROM store data?

p. 233 - 234 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, DVD+RW, and DVD-RAM

Click to view Web Link,click Chapter 6, Click Web Linkfrom left navigation, then click Blu-ray and HD DVDbelow Chapter 6

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

Tape

How is data stored on a tape?

p. 235 Next

Sequential access

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

Reads and writes data consecutively, like music tape

PC Cards and ExpressCard ModulesWhat are PC Cards and ExpressCard Modules?

p. 235 Figs. 6-22 Next

Adds capabilities to computer Credit-card-sized device

commonly used in notebook computers

Miniature Mobile Storage Media

What is miniature mobile storage media?

p. 236 Fig. 6-23 Next

Storage for small mobile devices

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

Miniature Mobile Storage Media

What is a USB Flash Drive?

p. 237 Fig. 6-24 Next

Plugs in a USB port on a computer or mobile device

Storage capacities up to 64 GB Making the floppy disk nearly

obsolete

Miniature Mobile Storage Media

What is a smart card?

p. 237 Fig. 6-25 Next

Stores data on microprocessor embedded in small card

Input, process, output, and storage capabilities

Microfilm and Microfiche

What are microfilm and microfiche?

p. 238 Fig. 6-26 Next

Images recorded using computer output microfilm

recorder

Store microscopic images of documents on roll or sheet of

film

Microfilm – 100 – to 215 – foot roll of film

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

Microfilm and Microfiche

How do life expectancies of various media compare?

p. 238 Fig. 6-27 Next

Microfilm and microfiche have longest life of any storage media

Putting It All Together

What are recommended storage devices for home users?

p. 239 Fig. 6-28 Next

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

Putting It All Together

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

p. 239 Fig. 6-28 Next

1 TB hard disk Online storage CD or DVD drive External hard drive for backup USB flash drive

Putting It All Together

What are recommended storage devices for mobile users?

p. 239 Fig. 6-28 Next

250 GB hard disk Online storage CD or DVD drive Card reader/writer Portable hard disk for backup USB flash drive

Putting It All Together

What are recommended storage devices for power users?

p. 239 Fig. 6-28 Next

2.5 TB hard disk Online storage CD or DVD drive Portable hard disk for backup USB flash drive

Putting It All Together

What are recommended storage devices for large business users?

p. 239 Fig. 6-28 Next

Desktop computer 1 TB hard disk CD or DVD drive Smart card reader Tape drive USB flash drive

Server or Mainframe Network storage server 40 TB hard disk system CD-ROM or DVD-ROM server Microfilm or microfiche

Summary of Storage

Internal hard disksInternal hard disks

External and Removable hard disksExternal and Removable hard disks

Floppy disksFloppy disks

CD-ROMsCD-ROMs

Recordable and Rewritable CDsRecordable and Rewritable CDs

DVD-ROMsDVD-ROMs

Blu-ray Discs and HD DVD discsBlu-ray Discs and HD DVD discs

Recordable and rewritable DVDsRecordable and rewritable DVDs

TapeTape

PC Cards and ExpressCard Modules

PC Cards and ExpressCard Modules

Flash memory cardsFlash memory cards

USB Flash DrivesUSB Flash Drives

Microfilm and microficheMicrofilm and microfiche

Chapter 6 Complete

Smart CardsSmart Cards