Transcript
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
Miniature Mobile Storage Media
What are common types of flash memory cards?
p. 376 Fig. 7-30
Miniature Mobile Storage Media
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
Miniature Mobile Storage Media
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
Putting It All Together
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
Putting It All Together
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
Putting It All Together
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
Putting It All Together
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
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