Discovering Computers 2009

Discovering Computers 2009

Chapter 7Storage

Chapter 7 Contents

Magnetic DisksMagnetic Disks

Optical DisksOptical Disks

TapeTape

PC Cards and Expresscard modulesPC Cards and Expresscard modules

Miniature mobile storage mediaMiniature mobile storage media

Microfilm and MocroficheMicrofilm and Mocrofiche

Enterprise storageEnterprise storage

Putting it all togetherPutting it all together

StorageStorage

Storage

What is __________?

p. 354 - 355 Fig. 7-1

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

Also called secondary storage

Storage

What is ______________?

p. 356

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

Storage Medium(hard disks, CDs, DVDs,USB flash drives, etc.)

Storage

How does volatility compare?

p. 355 - 356

No

nvo

lati

le

Storage medium is ____________—contents retained when power is off

Contents Contents retainedretained

Contents Contents available to useravailable to user

Memory(most RAM)

(chips on motherboard)

Screen Display

ON OFF

Vo

lati

le Display Display disappearsdisappears

Data andData andinstructions instructions

available to useravailable to user

Display Display appearsappears

Data and Data and instructions erasedinstructions erased

Memory is ________—holds data and instructions temporarily

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 ________________?

p. 356

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

Storage

What is _____________?

p. 357 Fig. 7-4

1. Time it takes storage device to locate item on storage medium2. Time required to deliver item from memory to processor

The speed of storage devices and memory measuring

Magnetic Disks : use magnetic particles

p. 357 Fig. 7-5

What are ______ and ________?

________is narrow

recording bandthat forms fullcircle on disk

__________stores up to512 bytes

of data

Magnetic Disks : use magnetic particles

p. 357 Fig. 7-5

A_______________________is the smallest unit of disk space that stores data and information, and consists of two to eight sectors

For reading and writing purposes, sectors are grouped into _______________.

Even if a file consists of only a few bytes, it uses an entire cluster.

Each cluster holds data from only one file, but one file can span many clusters.

Perpendicular recording

Magnetic Disks

What is a ______________?

p. 358 Fig. 7-6

High-capacity storage Consists of several

inflexible, circular platters that store items electronically

Components enclosed in airtight, sealed case for protection

Longitudinal recording

Magnetic Disks

What are characteristics of a hard disk?

p. 359 Fig. 7-7

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 MBps

Access time 8.5 ms

actualdisk

capacity

Magnetic Disks

How does a hard disk work?

p. 360 Fig. 7-8

Magnetic Disks

What is a _________?

p. 360 Fig. 7-9

Vertical section of track through all platters

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

Top view of platter

read/writehead

platter

sides

track

sector

side view of platter

cylinder

Magnetic Disks

What is a ___________?

p. 360-361 Fig. 7-10

Usually resultiing in a loss of data or sometimes loss of the entire drive Spinning creates cushion of air that floats read/write head above

platter

Occurs when read/write head touches platter surface

Magnetic Disks

What is a _____________?

p. 361 Fig. 7-11

Portion of memory that processor uses to store frequently accessed items

second requestfor data—to hard disk

first requestfor data—to disk cache

Magnetic Disks

What is _________?

p. 362

Redundant Array of Independent Disks A group of two or more integrated hard disks Connects multiple smaller disks into a single unit that

acts as a single large hard disk

Magnetic Disks

What is a ______________________?

p. 362 Fig. 7-13

Provide greater storage capacities than flash memory Smaller than notebook computer hard disks A __________________, as another type of miniature

hard disk, is a self-contained unit

Magnetic Disks

What are _______hard disks and ______________hard disks?

p. 363 Fig. 7-14

__________ hard disk—freestandinghard disk that connects to system unit

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

Used to back up or transfer files

SASSAScontroller supports many connectedcontroller supports many connected

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

scanners, digital cameras, and morescanners, digital cameras, and more

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

Magnetic Disks

What is a _________________?

p. 363 - 364

SCSISCSIcontroller supports up to fifteencontroller supports up to fifteen

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

printers, scanners, network cardsprinters, scanners, network cards

SATASATA (Serial Advanced Serial Advanced Technology AttachmentTechnology Attachment) )

controller uses serial signals to controller uses serial signals to transfer data, instructions, and transfer data, instructions, and

informationinformation

Chip and circuits that control transfer of items from disk

Magnetic Disks

What is ________________?

p. 364 - 365 Fig. 7-15

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

Magnetic Disks

What is a ____________?

p. 365 Fig. 7-16

Portable, inexpensive storage medium (also called diskette)

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

Optical Discs

What are ____________?

p. 366 Fig. 7-17

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

Optical Discs

How does a laser read data on an optical disc?

p. 367 Fig. 7-18

laserdiode

laserdiode

prism prism

light-sensingdiode

light-sensingdiode

0 1

lens lenspit land

disc label

Step 1.Laser diode shines a light beam towarddisc.

Step 2.If light strikesa pit, it scatters. If light strikes a land, it is reflected back toward diode.

Step 3.Reflected light is deflected to alight-sensing diode, which send a digital signals of 1 to computer. Absenceof reflected light is read as a digital signal of 0.

Optical Discs

How is data stored on an optical disc?

p. 367 Fig. 7-19

Typically stored in single track

Track divided

into evenly sized sectors that store items

Optical Discs

What is a ____________?

p. 369 Fig. 7-22

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

Optical Discs

What is the data transfer rate of a CD-ROM drive?

p. 369

75XRanges from 48X to 75X

or faster

75 75 150 KBps = 11,250 KBps 150 KBps = 11,250 KBps or 12.25 MBpsor 12.25 MBps75X is 150 KBps 75X is 150 KBps

(KB per second)(KB per second)

48X: 48X: 48 48 150 KBps = 7,200 KBps 150 KBps = 7,200 KBps

or 7.2 MBpsor 7.2 MBps

Optical Discs

What are ________ and ___________?

p. 370

Must haveCD recorder

or CD-R drive

Cannot erasedisc’s contents

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

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

multiple times

Must haveCD-RW softwareand CD-RW drive

Optical Discs

What is an _____________?

Stores photos from an online photo center in the jpg file format.

p. 370 - 371 Fig. 7-23

Optical Discs

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

p. 372 Fig. 7-24

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

Tape

What is ________?

p. 374 Fig. 7-27

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. 374

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 ModulesRemovable devices.

p. 374 Figs. 7-28

____________________: a thin credit card sized removable flash memory deice.

_____________________________________: a removable device, smaller than ______________.

They can be used for adding memory, storage, communications, multimedia, and security capabilites.

Miniature Mobile Storage Media

What is miniature mobile storage media?

p. 375 Fig. 7-29

Storage for small mobile devices


What are common types of flash memory cards?

p. 376 Fig. 7-30


What is a _______________?

p. 377 Fig. 7-32

Plugs in a USB port on a computer or mobile device Storage capacities up to 64 GB May eventually make the floppy disk nearly obsolete


What is a ______________?

p. 378 Fig. 7-33

Stores data on microprocessor embedded in small card

Input, process, output, and storage capabilities

Microfilm and Microfiche

What are ______________ and __________?

p. 379 Fig. 7-34

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

_____________ — 100- to215-foot roll of film

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

Microfilm and Microfiche

How do life expectancies of various media compare?

p. 379 Fig. 7-35

Microfilm and microfiche have longest life of any storage media

Putting It All Together

What are recommended storage devices for home users?

p. 380 Fig. 7-37

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


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

p. 380 Fig. 7-37

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


What are recommended storage devices for mobile users?

p. 380 Fig. 7-37

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


What are recommended storage devices for power users?

p. 380 Fig. 7-37

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


What are recommended storage devices for large business users?

p. 380 Fig. 7-37

Desktop computer1 TB hard diskCD or DVD driveSmart card readerTape driveUSB flash drive

Server or MainframeNetwork storage server40 TB hard disk systemCD or DVD serverMicrofilm 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 (BDs)Blu-ray Discs (BDs)

HD DVD discsHD DVD discs

Recordable and Rewritable DVDsRecordable and Rewritable DVDs

TapeTape

PC Cards and ExpressCard modules

PC Cards and ExpressCard modules

Flash memory cards and USB flash drives

Flash memory cards and USB flash drives

Chapter 7 Complete

Smart cards, microfilm, and microfiche

Smart cards, microfilm, and microfiche

Documents

Discovering Computers 2009