Discovering Computers Fundamentals Fifth Edition Chapter 6 Storage.
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Transcript of Discovering Computers Fundamentals Fifth Edition Chapter 6 Storage.
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