Discovering Computers 2009


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Discovering Computers 2009

  1. 1. Chapter 7 Storage
  2. 2. 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
  3. 3. Storage <ul><li>What is __________ ? </li></ul>p. 354 - 355 Fig. 7-1 <ul><ul><li>Holds data, instructions, and information for future use </li></ul></ul><ul><li>_______________ is physical material used for storage </li></ul><ul><li>Also called secondary storage </li></ul>
  4. 4. Storage <ul><li>What is ______________ ? </li></ul>p. 356 <ul><ul><li>Number of bytes (characters) a storage medium can hold </li></ul></ul>Kilobyte (KB) 1 thousand Megabyte (MB) 1 million Gigabyte (GB) 1 billion Terabyte (TB) 1 trillion Petabyte (PB) 1 quadrillion Exabyte (EB) 1 quintillion Zettabyte (ZB) 1 sextillion Yottabyte (YB) 1 septillion
  5. 5. Storage <ul><li>How does volatility compare? </li></ul>p. 355 - 356 Nonvolatile <ul><li>Storage medium is ____________ —contents retained when power is off </li></ul>Contents retained Contents available to user ON OFF Volatile Display disappears Data and instructions available to user Display appears Data and instructions erased <ul><li>Memory is ________ —holds data and instructions temporarily </li></ul>Storage Medium (hard disks, CDs, DVDs, USB flash drives, etc.) Memory (most RAM) (chips on motherboard) Screen Display
  6. 6. Storage <ul><li>What is a ________________ ? </li></ul>Writing Process of transferring items from memory to storage media p. 356 Reading Process 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
  7. 7. Storage <ul><li>What is _____________ ? </li></ul>p. 357 Fig. 7-4 <ul><ul><li>Time it takes storage device to locate item on storage medium </li></ul></ul><ul><ul><li>Time required to deliver item from memory to processor </li></ul></ul><ul><ul><li>The speed of storage devices and memory measuring </li></ul></ul>
  8. 8. Magnetic Disks : use magnetic particles <ul><li>What are ______ and ________ ? </li></ul>p. 357 Fig. 7-5 ________ is narrow recording band that forms full circle on disk <ul><ul><li>__________ stores up to 512 bytes of data </li></ul></ul>
  9. 9. Magnetic Disks : use magnetic particles p. 357 Fig. 7-5 <ul><ul><ul><li>A_______________________is the smallest unit of disk space that stores data and information, and consists of two to eight sectors </li></ul></ul></ul><ul><ul><ul><li>For reading and writing purposes, sectors are grouped into _______________. </li></ul></ul></ul><ul><ul><ul><li>Even if a file consists of only a few bytes, it uses an entire cluster. </li></ul></ul></ul><ul><ul><ul><li>Each cluster holds data from only one file, but one file can span many clusters. </li></ul></ul></ul>
  10. 10. Magnetic Disks <ul><li>What is a ______________ ? </li></ul>p. 358 Fig. 7-6 <ul><ul><li>High-capacity storage </li></ul></ul><ul><ul><li>Consists of several inflexible, circular platters that store items electronically </li></ul></ul><ul><ul><li>Components enclosed in airtight, sealed case for protection </li></ul></ul>Perpendicular recording Longitudinal recording
  11. 11. Magnetic Disks <ul><li>What are characteristics of a hard disk? </li></ul>p. 359 Fig. 7-7 actual disk capacity 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
  12. 12. Magnetic Disks <ul><li>How does a hard disk work? </li></ul>p. 360 Fig. 7-8
  13. 13. Magnetic Disks <ul><li>What is a _________ ? </li></ul>p. 360 Fig. 7-9 <ul><ul><li>Vertical section of track through all platters </li></ul></ul><ul><ul><li>Single movement of read/write head arms accesses all platters in ________ </li></ul></ul>T op view of platter read/write head platter sides track sector side view of platter cylinder
  14. 14. Magnetic Disks <ul><li>What is a ___________ ? </li></ul>p. 360-361 Fig. 7-10 <ul><ul><li>Usually resultiing in a loss of data or sometimes loss of the entire drive </li></ul></ul><ul><ul><li>Spinning creates cushion of air that floats read/write head above platter </li></ul></ul><ul><ul><li>Occurs when read/write head touches platter surface </li></ul></ul>
  15. 15. Magnetic Disks <ul><li>What is a _____________ ? </li></ul>p. 361 Fig. 7-11 <ul><ul><li>Portion of memory that processor uses to store frequently accessed items </li></ul></ul>second request for data—to hard disk first request for data—to disk cache
  16. 16. Magnetic Disks <ul><li>What is _________ ? </li></ul>p. 362 <ul><ul><li>Redundant Array of Independent Disks </li></ul></ul><ul><ul><li>A group of two or more integrated hard disks </li></ul></ul><ul><ul><li>Connects multiple smaller disks into a single unit that acts as a single large hard disk </li></ul></ul>
  17. 17. Magnetic Disks <ul><li>What is a ______________________ ? </li></ul>p. 362 Fig. 7-13 <ul><ul><li>Provide greater storage capacities than flash memory </li></ul></ul><ul><ul><li>Smaller than notebook computer hard disks </li></ul></ul><ul><ul><li>A __________________ , as another type of miniature hard disk, is a self-contained unit </li></ul></ul>
  18. 18. Magnetic Disks <ul><li>What are _______ hard disks and ______________ hard disks ? </li></ul>p. 363 Fig. 7-14 __________ hard disk —freestanding hard disk that connects to system unit __________ hard disk —hard disk that you insert and remove from hard disk drive <ul><li>Used to back up or transfer files </li></ul>
  19. 19. Magnetic Disks <ul><li>What is a _________________ ? </li></ul>p. 363 - 364 <ul><li>Chip and circuits that control transfer of items from disk </li></ul>SAS controller supports many connected devices at once, including hard disks, CD and DVD drives, printers, scanners, digital cameras, and more EIDE ( E nhanced I ntegrated D rive E lectronics) controller supports four hard disks, provides connections for CD and DVD drives SCSI controller supports up to fifteen devices including hard disks, CD and DVD drives, tape drives, printers, scanners, network cards SATA ( Serial Advanced Technology Attachment ) controller uses serial signals to transfer data, instructions, and information
  20. 20. Magnetic Disks <ul><li>What is ________________ ? </li></ul>p. 364 - 365 Fig. 7-15 <ul><ul><li>Others can be authorized to access your data </li></ul></ul><ul><ul><li>Service on Web that provides storage for minimal monthly fee </li></ul></ul><ul><ul><li>Files can be accessed from any computer with Web access </li></ul></ul><ul><ul><li>Large files can be downloaded instantaneously </li></ul></ul>
  21. 21. Magnetic Disks <ul><li>What is a ____________ ? </li></ul>p. 365 Fig. 7-16 <ul><ul><li>Portable, inexpensive storage medium ( also called diskette ) </li></ul></ul><ul><ul><li>Thin, circular, flexible film enclosed in 3.5” wide plastic shell </li></ul></ul>
  22. 22. Optical Dis c s <ul><li>What are ____________ ? </li></ul>p. 366 Fig. 7-17 <ul><ul><li>Most PCs include an optical disc drive </li></ul></ul><ul><ul><li>Flat, round, portable metal discs made of metal, plastic, and lacquer </li></ul></ul><ul><ul><li>Can be read only or read/write </li></ul></ul>
  23. 23. Optical Discs <ul><li>How does a laser read data on an optical disc? </li></ul>p. 367 Fig. 7-18 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. laser diode laser diode prism prism light- sensing diode light- sensing diode 0 1 lens lens pit land disc label 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.
  24. 24. Optical Discs <ul><li>How is data stored on an optical disc? </li></ul>p. 367 Fig. 7-19 <ul><ul><li>Typically stored in single track </li></ul></ul><ul><ul><li>Track divided into evenly sized sectors that store items </li></ul></ul>
  25. 25. Optical Discs <ul><li>What is a ____________ ? </li></ul>p. 369 Fig. 7-22 <ul><ul><li>C ompact d isc r ead- o nly m emory </li></ul></ul><ul><ul><li>Cannot erase or modify contents </li></ul></ul><ul><ul><li>Typically holds 650 MB to 1 GB </li></ul></ul><ul><ul><li>Commonly used to distribute multimedia and complex software </li></ul></ul>
  26. 26. Optical Discs <ul><li>What is the data transfer rate of a CD-ROM drive? </li></ul>p. 369 75X Ranges from 48X to 75X or faster 75  150 KBps = 11,250 KBps or 12.25 MBps 75X is 150 KBps (KB per second) 48X: 48  150 KBps = 7,200 KBps or 7.2 MBps
  27. 27. Optical Discs <ul><li>What are ________ and ___________ ? </li></ul>p. 370 Must have CD recorder or CD-R drive Cannot erase disc’s contents ( c ompact d isc- r ecordable) — c disc you can write on once _________ ( c ompact d isc- r e w ritable) — ce erasable disc you can write on multiple times Must have CD-RW software and CD-RW drive
  28. 28. Optical Discs <ul><li>What is an _____________ ? </li></ul><ul><li>Stores photos from an online photo center in the jpg file format. </li></ul>p. 370 - 371 Fig. 7-23
  29. 29. Optical Discs <ul><li>What is a ___________ (digital versatile disc-ROM or digital video disc-ROM)? </li></ul>p. 372 Fig. 7-24 <ul><ul><li>Stores databases, music, complex software, and movies </li></ul></ul><ul><ul><li>Blu-ray discs have storage capacity of up to 100 GB </li></ul></ul><ul><ul><li>HD-DVD discs have storage capacity of up to 60 GB </li></ul></ul><ul><ul><li>HD-VMDs have storage capacity of up to 40 GB or more </li></ul></ul><ul><ul><li>UMD can store up to 1.8 GB </li></ul></ul>
  30. 30. Tape <ul><li>What is ________ ? </li></ul>p. 374 Fig. 7-27 <ul><ul><li>Magnetically coated plastic ribbon capable of storing large amounts of data at low cost </li></ul></ul><ul><ul><li>Primarily used for backup </li></ul></ul>
  31. 31. Tape <ul><li>How is data stored on a tape? </li></ul>p. 374 <ul><ul><li>Sequential access </li></ul></ul><ul><ul><ul><li>Unlike direct access — used on hard disks, CDs, and DVDs — which can locate particular item immediately </li></ul></ul></ul><ul><ul><ul><li>Reads and writes data consecutively, like music tape </li></ul></ul></ul>
  32. 32. PC Cards and ExpressCard Modules <ul><li>Removable devices. </li></ul>p. 374 Figs. 7-28 <ul><li>____________________: a thin credit card sized removable flash memory deice. </li></ul><ul><li>_____________________________________: a removable device, smaller than ______________. </li></ul><ul><li>They can be used for adding memory, storage, communications, multimedia, and security capabilites. </li></ul>
  33. 33. Miniature Mobile Storage Media <ul><li>What is miniature mobile storage media? </li></ul>p. 375 Fig. 7-29 <ul><ul><li>Storage for small mobile devices </li></ul></ul>
  34. 34. Miniature Mobile Storage Media <ul><li>What are common types of flash memory cards? </li></ul>p. 376 Fig. 7-30
  35. 35. Miniature Mobile Storage Media <ul><li>What is a _______________ ? </li></ul>p. 377 Fig. 7-32 <ul><ul><li>Plugs in a USB port on a computer or mobile device </li></ul></ul><ul><ul><li>Storage capacities up to 64 GB </li></ul></ul><ul><ul><li>May eventually make the floppy disk nearly obsolete </li></ul></ul>
  36. 36. Miniature Mobile Storage Media <ul><li>What is a ______________ ? </li></ul>p. 378 Fig. 7-33 <ul><ul><li>Stores data on microprocessor embedded in small card </li></ul></ul><ul><ul><li>Input, process, output, and storage capabilities </li></ul></ul>
  37. 37. Microfilm and Microfiche <ul><li>What are ______________ and __________ ? </li></ul>p. 379 Fig. 7-34 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”
  38. 38. Microfilm and Microfiche <ul><li>How do life expectancies of various media compare? </li></ul>p. 379 Fig. 7-35 <ul><li>Microfilm and microfiche have longest life of any storage media </li></ul>
  39. 39. Putting It All Together <ul><li>What are recommended storage devices for home users? </li></ul>p. 380 Fig. 7-37 <ul><li>320 GB hard disk </li></ul><ul><li>Online storage </li></ul><ul><li>CD or DVD drive </li></ul><ul><li>Card reader/writer </li></ul><ul><li>USB flash drive </li></ul>
  40. 40. Putting It All Together <ul><li>What are recommended storage devices for small office/home office (SOHO) users? </li></ul>p. 380 Fig. 7-37 <ul><li>1 TB hard disk </li></ul><ul><li>Online storage </li></ul><ul><li>CD or DVD drive </li></ul><ul><li>External hard drive for backup </li></ul><ul><li>USB flash drive </li></ul>
  41. 41. Putting It All Together <ul><li>What are recommended storage devices for mobile users? </li></ul>p. 380 Fig. 7-37 <ul><li>250 GB hard disk </li></ul><ul><li>Online storage </li></ul><ul><li>CD or DVD drive </li></ul><ul><li>Card reader/writer </li></ul><ul><li>Portable hard disk for backup </li></ul><ul><li>USB flash drive </li></ul>
  42. 42. Putting It All Together <ul><li>What are recommended storage devices for power users? </li></ul>p. 380 Fig. 7-37 <ul><li>2.5 TB hard disk </li></ul><ul><li>Online storage </li></ul><ul><li>CD or DVD drive </li></ul><ul><li>Portable hard disk for backup </li></ul><ul><li>USB flash drive </li></ul>
  43. 43. Putting It All Together <ul><li>What are recommended storage devices for large business users? </li></ul>p. 380 Fig. 7-37 <ul><li>Desktop computer </li></ul><ul><ul><li>1 TB hard disk </li></ul></ul><ul><ul><li>CD or DVD drive </li></ul></ul><ul><ul><li>Smart card reader </li></ul></ul><ul><ul><li>Tape drive </li></ul></ul><ul><ul><li>USB flash drive </li></ul></ul><ul><li>Server or Mainframe </li></ul><ul><ul><li>Network storage server </li></ul></ul><ul><ul><li>40 TB hard disk system </li></ul></ul><ul><ul><li>CD or DVD server </li></ul></ul><ul><ul><li>Microfilm or microfiche </li></ul></ul>
  44. 44. 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