Storage
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Storage holds data and information for future use on physical storage media like disks, tapes, and flash memory. Common storage capacities are measured in kilobytes, megabytes, gigabytes and terabytes. Storage media can be volatile, like RAM memory, which loses data when power is removed, or non-volatile like hard disks, which retain data without power. Common storage devices include floppy disks, hard disks, CDs, DVDs, flash memory cards, and online cloud storage services. Larger businesses may use tape drives, servers, and microfilm for archiving and backups.
Storage
- 2. Storage What is storage? p. 354 Fig. 7-1 Next Holds data, instructions, and information for future use Storage medium is physical material used for storage Also called secondary storage
- 3. Storage What is capacity? p. 356 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
- 4. Storage Medium (floppy disks, Zip disks, hard disks, CDs) Storage How does volatility compare? p. 356 Next Nonvolatile Storage medium is nonvolatile—contents retained when power is off ContentsContents retainedretained ContentsContents available to useravailable to user Memory (most RAM) (chips on motherboard) Screen Display ON OFF Volatile DisplayDisplay disappearsdisappears Data andData and instructionsinstructions available to useravailable to user DisplayDisplay appearsappears Data andData and instructions erasedinstructions erased Memory is volatile—holds data and instructions temporarily
- 5. WritingWriting Process of transferringProcess of transferring items from memoryitems from memory to storage mediato storage media WritingWriting Process of transferringProcess of transferring items from memoryitems from memory to storage mediato storage media Storage What is a storage device? p. 356 Next ReadingReading Process of transferringProcess of transferring items from storageitems from storage media to memorymedia to memory ReadingReading Process of transferringProcess of transferring items from storageitems from storage media to memorymedia to memory Hardware thatHardware that records andrecords and retrieves itemsretrieves items to and fromto and from storage mediastorage media Functions as source of input Creates output
- 6. Storage What is access time? p. 357 Fig. 7-4 Time it takes storage device to locate item on storage medium Floppy Disk Small files to be transported Secondary Storage Primary Storage Hard Disk Flash Memory Cards and USB Flash Drives CDs and DVDs Tape Items waiting to be interpreted and executed by the processor Operating system, application software, user data and information Digital pictures or files to be transported Software, backups, movies, music Backups Memory (most RAM) Stores … Next Time required to deliver item from memory to processor faster transfer rates slower transfer rates
- 7. Magnetic Disks p. 357 Fig. 7-5 Next What are tracks and sectors? Track is narrow recording band that forms full circle on disk Sector stores up to 512 bytes of data Formatting prepares disk for use and marks bad sectors as unusable
- 8. Magnetic Disks What is a floppy disk? p. 358 Next Portable, inexpensive storage medium (also called diskette) Thin, circular, flexible film enclosed in 3.5” wide plastic shell shutter shell liner magnetic coating flexible thin film metal hub Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Floppy Disks below Chapter 7
- 9. Magnetic Disks What is a floppy disk drive? p. 358 Fig. 7-6 Next Floppy disk drive built into a desktop computer External floppy disk drive attaches to a computer with a cable Also called secondary storage One floppy drive, named drive A Device that reads from and writes to floppy disk
- 10. Magnetic Disks What is a write-protect notch? p. 359 Fig. 7-7 Next Small opening with a cover that you slide Protects floppy disk from being erased accidentally hole on this side means disk is high density hole on this side means disk is high density write-protected not write-protected notch closed means you can write on the disk notch closed means you can write on the disk notch open means you cannot write on the disk notch open means you cannot write on the disk
- 11. Magnetic Disks What is a Zip disk? p. 359 Fig. 7-9 Next Magnetic medium that stores 100 MB to 750 MB of data Zip disks require a Zip drivec—chigh capacity drive that reads from and writes on a Zip disk Used to back up and to transfer files Backup is duplicate of file, program, or disk in case original is lost c Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Zip Disks below Chapter 7
- 12. Magnetic Disks What is a hard disk? p. 360 Fig. 7-10 Next hard disk installed in system unit High-capacity storage Consists of several inflexible, circular platters that store items electronically Components enclosed in airtight, sealed case for protection
- 13. Magnetic Disks What are characteristics of a hard disk? p. 361 Fig. 7-11 Next Sample Hard Disk Characteristics Advertised capacity 120 GB Platters 3 Read/write heads 6 Cylinders 16,383 Bytes per second 512 Sectors per track 63 Sectors per drive 234,441,648 Revolutions per minute 7,200 Transfer rate 133 MB per second Access time 8.9 ms actual disk capacity
- 14. Magnetic Disks What is a head crash? p. 362 Fig. 7-14 Next clearance read/write head platter hair dust smoke 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
- 15. hard disk Next Magnetic Disks What is a disk cache? p. 363 Fig. 7-15 Portion of memory that processor uses to store frequently accessed items second request for data—to hard disk disk cache first request for data—to disk cache processor
- 16. Next Magnetic Disks What is a miniature hard disk? p. 363 Fig. 7-16 Provide users with greater storage capacities than flash memory Some have a form factor of less than 1 inch Storage capacities range from 2 GB to 100 GB
- 17. Magnetic Disks What are external hard disks and removable hard disks? p. 364 Fig. 7-17 Next External hard disk—freestanding hard disk that connects to system unit Removable hard disk—hard disk that you insert and remove from hard disk drive Used to back up or transfer files Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Hard Disks below Chapter 7
- 18. Magnetic Disks What is online storage? p. 365 Fig. 7-18 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 Large files can be downloaded instantaneously Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Online Storage below Chapter 7
- 19. Push the same button to close the tray. Optical Discs What are optical discs? p. 366 Fig. 7-19 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, label side up. Push the button to slide out the tray.
- 20. Optical Discs How should you care for an optical disc? p. 368 Fig. 7-22 Next Do store the disc in a jewel box when not in use Do hold a disc by its edges Do not eat, smoke, or drink near a disc Do not stack discs Do not expose the disc to excessive heat or sunlight Do not touch the underside of the disc
- 21. Optical Discs What is a CD-ROM? p. 369 Fig. 7-24 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 7, Click Web Link from left navigation, then click CD-ROMs below Chapter 7
- 22. Optical Discs What is a Picture CD? p. 370 Fig. 7-25 Next Film developers offer Picture CD service Can be modified using photo editing software Stores digital versions of roll of film Step 3. At home, print images from Picture CD on your ink-jet photo printer. At a store, print images to Picture CD at kiosk. Step 1. Drop off film to be developed. Mark the Picture CD box on the film-processing envelope. Step 2. When you pick up prints and negatives, a Picture CD contains digital images of each photograph. Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Picture CDs below Chapter 7
- 23. Optical Discs What are CD-Rs and CD-RWs? p. 371 Next Must have CD recorder or CD-R drive Cannot erase disc’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 have CD-RW software and CD-RW drive Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click CD-Rs and CD-RWs below Chapter 7
- 24. Optical Discs What is a DVD-ROM (digital versatile disc-ROM or digital video disc-ROM)? p. 372 Fig. 7-26 Next High capacity disc capable of storing 4.7 GB to 17 GB Must have DVD-ROM drive or DVD player to read DVD-ROM Stores databases, music, complex software, and movies Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click DVDs below Chapter 7
- 25. Optical Discs How does a DVD-ROM store data? p. 372 Fig. 7-27 Next Two layers of pits are used, lower layer is semitransparent so laser can read through Some are double-sided Blu-Ray discs currently have a storage capacity of up to 27 GB
- 26. Tape What is tape? p. 374 Fig. 7-28 Next Magnetically coated plastic ribbon capable of storing large amounts of data at low cost Primarily used for backup Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Tape below Chapter 7
- 27. Tape How is data stored on a tape? p. 374 Next Sequential access Unlike direct access — used on floppy disks, Zip disks, hard disks, CDs, and DVDs — which can locate particular item immediately Reads and writes data consecutively, like music tape
- 28. PC Cards What is a PC Card? p. 374 Figs. 7-29–7-30 Next Adds capabilities to computer Credit-card-sized device commonly used in notebook computers
- 29. Miniature Mobile Storage Media What is miniature mobile storage media? p. 375 Fig. 7-31 Next Storage for small mobile devices
- 30. Miniature Mobile Storage Media What are common types of flash memory cards? p. 376 Fig. 7-32 Next Smart Media xD Picture Card CompactFlash Secure Digital Memory Stick Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Flash Memory Cards below Chapter 7
- 31. Miniature Mobile Storage Media What is a USB Flash Drive? p. 377 Fig. 7-34 Next Plugs in a USB port on a computer or mobile device Storage capacities up to 4 GB May eventually make the floppy disk obsolete
- 32. Miniature Mobile Storage Media What is a smart card? p. 378 Fig. 7-35 Next Stores data on microprocessor embedded in small card Input, process, output, and storage capabilities Click to view Web Link, click Chapter 7, Click Web Link from left navigation, then click Smart Cards below Chapter 7
- 33. Microfilm and Microfiche What are microfilm and microfiche? p. 379 Fig. 7-36 Next Images recorded usingImages recorded using computer output microfilm recordercomputer output microfilm recorder Store microscopic images ofStore microscopic images of documents on roll or sheet of filmdocuments on roll or sheet of film Microfilm — 100- to 215-foot roll of film Microfiche — small sheet of film, usually 4” × 6”
- 34. Microfilm and Microfiche How do life expectancies of various media compare? p. 379 Fig. 7-37 Next Microfilm and microfiche have longest life of any storage media
- 35. Putting It All Together What are recommended storage devices for home users? p. 380 Fig. 7-38 Next Home 80 GB hard disk Online storage CD or DVD drive Card reader/writer USB flash drive and/or 3.5-inch floppy disk drive
- 36. Putting It All Together What are recommended storage devices for small office/home office (SOHO) users? p. 380 Fig. 7-38 Next 750 MB Zip drive 120 GB hard disk Online storage CD or DVD drive External hard drive for backup USB flash drive and/or 3.5-inch floppy disk driveSmall Office/ Home Office (SOHO)
- 37. Putting It All Together What are recommended storage devices for mobile users? p. 380 Fig. 7-38 Next 80 GB hard disk Online storage CD or DVD drive Card reader/writer Portable hard disk for backup USB flash drive, and/or 2 GB PC Card hard disk, and/or 3.5-inch floppy disk driveMobile
- 38. Putting It All Together What are recommended storage devices for power users? p. 380 Fig. 7-38 Next CD or DVD drive 300 GB hard disk Online storage Portable hard disk for backup USB flash drive and/or 3.5-inch floppy disk drive Power
- 39. Putting It All Together What are recommended storage devices for large business users? p. 380 Fig. 7-38 Next Desktop computer 160 GB hard disk CD or DVD drive Smart card reader Tape drive USB flash drive and/or 3.5-inch floppy disk drive Server or Mainframe Network storage server 40 TB hard disk system CD-ROM or DVD-ROM server Microfilm or microfiche Large Business
- 40. Summary of Storage Floppy disksFloppy disks Zip disksZip disks Internal hard disksInternal hard disks Portable hard disksPortable hard disks Recordable CDsRecordable CDs Rewritable CDsRewritable CDs DVD-ROMsDVD-ROMs Recordable DVDsRecordable DVDs Rewritable DVDsRewritable DVDs TapeTape PC CardsPC Cards 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