Discovering Computers 2009 Chapter 7 Storage

Chapter 7 Contents Magnetic Disks Optical Disks Tape PC Cards and Expresscard modules Miniature mobile storage media Microfilm and Mocrofiche Enterprise storage Putting it all together Storage

What is __________? p 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 Nonvolatile  Storage medium is ____________—contents retained when power is off Contents retained Contents available to user Memory (most RAM) (chips on motherboard) Screen Display ONOFF Volatile Display disappears Data and instructions available to user Display appears Data and instructions erased  Memory is ________—holds data and instructions temporarily

Writing Process of transferring items from memory to storage media Writing Storage What is a ________________? p. 356 Reading Process of transferring items from storage media to memory Reading Hardware that records and retrieves items to and from storage media Functions as source of input Creates output

Storage What is _____________? p. 357 Fig Time it takes storage device to locate item on storage medium 2.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 band that forms full circle on disk __________ stores up to 512 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 capacity500 GB Platters4 Read/write heads8 Cylinders16,383 Bytes per second512 Sectors per track63 Sectors per drive973,773,168 Revolutions per minute7,200 Transfer rate300 MBps Access time8.5 ms actual disk 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 platters in ________ Top view of platter read/write head platter sides track sector side view of platter cylinder

Magnetic Disks What is a ___________? p Fig  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  Portion of memory that processor uses to store frequently accessed items second request for data—to hard disk first request for 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  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 __________ hard disk—freestanding hard disk that connects to system unit __________hard disk—hard disk that you insert and remove from hard disk drive  Used to back up or transfer files

SAS controller supports many connected devices at once, including hard disks, CD and DVD drives, printers, scanners, digital cameras, and more EIDEEnhancedIntegratedDrive Electronics) controller supports four hard disks, provides connections for CD and DVD drives EIDE (Enhanced Integrated Drive Electronics) controller supports four hard disks, provides connections for CD and DVD drives Magnetic Disks What is a _________________? p SCSI controller supports up to fifteen devices including hard disks, CD and DVD drives, tape drives, printers, scanners, network cards SATASerial Advanced Technology Attachment) controller uses serial signals to transfer data, instructions, and information 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

Magnetic Disks What is ________________? p Fig  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  Portable, inexpensive storage medium (also called diskette) Thin, circular, flexible film enclosed in 3.5” wide plastic shell

Optical Discs What are ____________? p. 366 Fig  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 laser diode prism light- sensing diode 01 lens pitland disc label Step 1. Laser diode shines a light beam toward disc. Step 2. If light strikes a pit, it scatters. If light strikes a land, it is reflected back toward diode. Step 3. Reflected light is deflected to a light-sensing diode, which send a digital signals of 1 to computer. Absence of reflected light is read as a digital signal of 0.

Optical Discs How is data stored on an optical disc? p. 367 Fig  Typically stored in single track  Track divided into evenly sized sectors that store items

Optical Discs What is a ____________? p. 369 Fig  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 X Ranges from 48X to 75X or faster 75  150 KBps = 11,250 KBps or MBps 75X is 150 KBps (KB per second) 48X: 48  150 KBps = 7,200 KBps or 7.2 MBps

Optical Discs What are ________ and ___________? p. 370 Must have CD recorder or CD-R drive Cannot erase disc’s contents (compact disc-recordable) — c disc you can write on once _________ (compact disc-rewritable) — ce erasable disc you can write on multiple times Must have CD-RW software and CD-RW drive

Optical Discs What is an _____________? Stores photos from an online photo center in the jpg file format. p Fig. 7-23

Optical Discs What is a ___________(digital versatile disc-ROM or digital video disc-ROM)? p. 372 Fig  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  Magnetically coated plastic ribbon capable of storing large amounts of 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 Modules Removable devices. p. 374 Figs  ____________________: 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  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  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  Stores data on microprocessor embedded in small card  Input, process, output, and storage capabilities

Microfilm and Microfiche What are ______________ and __________? p. 379 Fig Images recorded using computer output microfilm recorder Store microscopic images of documents on roll or sheet of film _____________ — 100- to 215-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  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  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  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  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  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  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 or DVD server  Microfilm or microfiche

Summary of Storage Internal hard disks External and removable hard disks Floppy disks CD-ROMs Recordable and Rewritable CDs DVD-ROMs Blu-ray Discs (BDs) HD DVD discs Recordable and Rewritable DVDs Tape PC Cards and ExpressCard modules Flash memory cards and USB flash drives Chapter 7 Complete Smart cards, microfilm, and microfiche