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  • 1. Computers in Your Future 2004 Bryan Pfaffenberger and Bill Daley Copyright © 2003 Prentice Hall, Inc Slides created by Bob Koziel
  • 2. Tips for using the slide show
    • Use MS Power Point XP to view the presentation. Earlier versions will not show the animations correctly.
    • Slides with : Click the slide to view all of its sections and animations. Some slides need to be clicked several times.
    • will appear once the last object on the slide has appeared. Click to go to the next slide.
    • represents an Internet link that will take you to the Web site when you click on it. Internet connection required.
    • Clicking on the or icon will take you to the previous or the next slide.
    • Slides with videos or sounds: Click on the picture to view videos or listen to sounds.
    NEXT SLIDE I NEXT SLIDE Copyright © 2003 Prentice Hall, Inc
  • 3. Tips Addendum
    • This set of slides contain video and/or sound files.
    • Preview the slide show on the computer that will be used in class.
    • If the video or sound does not play, follow one of the set of directions below.
    • Slide Show View
    • 1. Click on the video or sound image.
    • 2. A dialog box will appear that will enable you to locate the file.
    • 3. Select the location where the PPTs are stored on the hard drive, server, or CD.
    • 4. Open the appropriate folder and select the appropriate file.
    • 5. Click Open.
    • 6. Click on the video or sound image again.
    • 7. Save the PPT with the new link.
    Normal View 1. Right-click on the video or sound image. 2. For videos, point to Media Clip Object and select Play . 3. For sounds, select Play Sound . 4. A dialog box will appear that will enable you to locate the file. 5. Follow directions 3-6 in Slide Show View . 6. Save the PPT with the new link. NEXT SLIDE Copyright © 2003 Prentice Hall, Inc
  • 4.
    • Chapter 4
    • Storing Data: Electronic Filing Cabinets
    COMPUTERS IN YOUR FUTURE 2004 by Bryan Pfaffenberger and Bill Daley
    • Differences between memory and storage
    • How storage media are categorized
    • How a storage device’s performance is measured
    • How data is stored on hard and floppy disks
    • Characteristics of hard drives
    • Uses of removable disks
    • Types of optical storage media
    • New types of storage media
    Chapter 4 Storing Data: Electronic Filing Cabinets What You Will Learn NEXT SLIDE
  • 5. Memory vs. Storage
    • Storage , also known as mass media or auxiliary storage , refers to the various media on which a computer system can store data.
    • Storage devices hold programs and data in units called files .
    • Files are stored in directories or folders .
    • Memory is a temporary workplace where the computer transfers the contents of a file while it is being used.
    Hard Drive RAM Memory NEXT SLIDE
  • 6. Why is storage necessary?
    • Storage:
    • Retains data when the computer is turned off.
    • Is cheaper than memory.
    • Plays an important role during startup.
    • Plays an input role when starting applications.
    • Is needed for output.
    • Devices can hold a large amount of data.
  • 7. Storage Devices
    • Storage devices are:
    • Hardware that is capable of retaining data when the electricity is turned off.
    • Able to read (retrieve) data from a storage medium (disk/tape).
    • Able to write (record) data to a storage medium.
  • 8. Types of Storage Technologies
    • Sequential – Hardware that reads and writes data in a serial (one after the other) fashion.
    • Random-Access – Hardware that reads and writes data without going through a sequence of locations.
    • Magnetic – Hardware that uses disks or tapes that are coated with magnetic material.
    • Optical – Hardware that uses laser beams to read data from plastic disks.
    • Solid State – Devices that use nonvolatile memory chips to read and write data.
  • 9. Sequential – Magnetic Storage Random-Access – Magnetic Storage Tape Backup Unit Floppy Drive Hard Drive Jaz Drive Zip Drive NEXT SLIDE
  • 10. Sequential – Optical Storage Magnetic – Optical Storage CD-ROM / DVD Drive Magneto-Optic (MO) Drive NEXT SLIDE
  • 11. Solid State Storage CompactFlash Memory Flash Memory Smart Card Micro Drive Memory Stick PC Card NEXT SLIDE
  • 12. The Storage Hierarchy
    • Storage hierarchy consists of three levels. They are:
    • Online storage – Also called primary storage , it is made up of the storage devices that are actively available to the computer system. User action is not required.
    • Near-online storage – Also called secondary storage , it is not readily available to the computer system. The user performs an action, such as inserting a disk, to make it available.
    • Offline storage – Also called tertiary storage or archival storage , it is not readily available to the computer system. Devices such as tape backup units store data for archival purposes.
  • 13. Capacity and Speed of Storage Devices
    • A storage device’s performance is measured by:
    • Capacity – The number of bytes of data that a device can hold.
    • Access Time – The amount of time, in milliseconds (ms), it takes for the device to begin reading data.
    Floppy Disk Hard Drive CD ROM / DVD Capacity – 720 KB to 1.44 MB Access Time – 100ms Capacity – Up to 80 GB Access Time – 6 to 12ms Capacity – CD-ROM 650 MB; DVD 17 GB Access Time – 80 to 800ms NEXT SLIDE
  • 14. Disks and Disk Drives
    • A disk or diskette is a portable storage medium.
    • Disks are circular plastic disks coated with a magnetically sensitive film.
    • Disks work with a disk drive.
    • High-density floppy disks are commonly used today.
      • Floppy disks store 1.44 MB of data.
    • SuperDisk and High FD disks store up to 250 MB of data and are downwardly compatible with floppy disks.
    • Zip disks store up to 750 MB of data and are not downwardly compatible with floppy disks.
  • 15. Protecting Your Data on Disks NEXT SLIDE
  • 16. How Disk Drives Work
    • Once inserted, the floppy disk spins on a spindle.
    • The head actuator moves the read/write head over the surface of the disk to the location of the data to be read.
    • Data is read into computer’s memory.
    Click on picture to view video NEXT SLIDE
  • 17. Disk Organization
    • A disk is formatted –that is, it is divided into tracks and sectors and a file allocation table ( FAT ) is created.
      • Track – circular band
      • Sector – pie shaped section
      • Cluster – two or more adjacent sectors
      • FAT – keeps track of specific locations of files
    Track Sector Cluster NEXT SLIDE
  • 18. How Hard Disks Work
    • Hard disks are a high-speed, high-capacity storage devices.
    • They contain metal disks called platters.
    • They contain two or more stacked platters with read/write heads for each side.
    • They work similarly to floppy disk drives.
    • Hard disks can be divided into partitions to enable computers to work with more than one operating system.
    Platter Read/Write head I NEXT SLIDE
  • 19. Factors Affecting a Hard Disk’s Performance
    • Seek time or positioning performance – How quickly the read/write head positions itself and begins transferring information. It is measured in milliseconds (ms).
    • Spindle speed or transfer performance – How quickly the drive transfers data. It is measured in rotations per minute (RPM).
    • Latency – The time it takes for the spinning platter to bring the desired data to the read/write head. It is measured in milliseconds (ms).
  • 20. Hard Disk Interfaces
    • A hard disk controller provides an interface which enables the hard disk to communicate with the CPU.
    • Types of interfaces:
      • Integrated Drive Electronics (IDE) , also called ATA or IDE/ATA
      • Ultra DMA/66
      • Ultra DMA/100
      • Small Computer System Interface (SCSI)
  • 21. Removable Hard Disks
    • Removable hard disks contain platters that are enclosed in a cartridge which can be inserted or removed from a drive.
    • They are used for data archiving and data backup.
    Jaz Drive NEXT SLIDE
  • 22. Magnetic Tape
    • Magnetic tape backup units store large amounts of data that are not used frequently.
    • They use a cassette-type reel-to-reel plastic tape.
    Tape Backup Unit NEXT SLIDE
  • 23. CD-ROM Disks and Drives
    • CD-ROM stands for C ompact D isk- R ead O nly M emory.
    • CD-ROM drives can not write data to disks.
    • They are capable of storing 650 MB of data.
    • They are used for storing operating systems, large application programs, and multimedia programs.
  • 24. CD-R and CD-RW Disks and Recorders
    • CD-R
    • Disks that can be read and written to.
    • Disks can only be written to “once”.
    • Drives that are capable of reading and writing data are needed.
    • CD-RW
    • Disks that can be read and written to.
    • Disks are erasable.
    • Disks can be written to many times.
    • Drives that are capable of reading, writing and erasing data are needed.
  • 25. DVD-ROM Disks and Drives
    • DVD stands for D igital V ideo D isk.
    • They use technology similar to CD-ROM.
    • They are capable of storing up to 17GB of data.
    • Their data transfer rate is comparable to that of hard disk drives.
    • They are compatible with CD-ROM disks.
    • DVD-RAM – Has the ability to read/write data.
  • 26. Other Optical Storage Technologies
    • Write Once, Read Many (WORM) systems use 12-inch optical disks that store up to 15 GB.
    • Magneto-Optical (MO) disks are erasable and they combine magnetic principles with optical technology.
    Magnet-Optical Drive NEXT SLIDE
  • 27. Storage Horizons
    • Florescent multilayer disc - read-only memory (FMD-ROM) uses optical technology to create disks with up to 100 layers of data.
      • Laser beams strike the disc’s fluorescent layers.
      • Up to 1 terabyte (TB) of data can be stored on each disc.
  • 28. Solid State Storage Devices
    • Solid state storage devices use nonvolatile memory chips to retain data.
    • They do not have moving parts.
    • They are small, lightweight, reliable, and portable.
  • 29. PC Cards
    • PC or PCMCIA card – Credit card-sized device used mainly with notebook computers.
    • Their various functions include:
      • Modems
      • Network adapters
      • Additional memory or storage
  • 30. Flash Memory Cards
    • Flash memory card – A wafer-thin card used with cellular phones, MP3 players, and digital cameras.
    • Types of flash memory cards:
      • SmartMedia card
      • CompactFlash card
      • Sony’s Memory Stick
    CompactFlash Memory Stick SmartMedia NEXT SLIDE
  • 31. Smart Cards
    • Smart card – Credit card-sized device combining flash memory with a microprocessor.
    • It is used as a credit card.
    • They offer more functionality, greater convenience, and higher safety than credit cards.
  • 32. Enterprise Storage Systems
    • Enterprise storage systems are developed by corporations to cope with their information storage needs.
    • They use several storage technologies:
      • Tape libraries
      • Hard disks
      • Optical disc libraries
      • Tape backup systems
    • A new technology being developed is the Storage area network – Links high-capacity storage devices to all of the organizations servers .
  • 33. Chapter 4 Summary
    • Memory makes software and data available for the CPU’s use.
    • RAM is volatile.
    • Storage devices are nonvolatile.
    • Storage devices are categorized by:
      • Operations (read-only or read/write)
      • Data access (sequential or random-access)
      • Technology (magnetic, optical, or solid state)
      • Hierarchy (online, near-online, or offline)
    • Disk organization includes:
      • Tracks
      • Sectors
      • Clusters
      • File allocation tables
  • 34. Chapter 4 Summary cont .
    • Hard disks store more data than other storage devices.
    • A hard disk’s performance is measured by its positioning performance and transfer rate.
    • IDE and SCSI are two hard drive interfaces.
    • Optical storage devices include:
      • CD-ROM– Read-only
      • CD-R– Record once
      • CD-RW– Erasable, write repeatedly
      • DVD-ROM– Read-only
      • DVD-RAM– Read/write
  • 35.
    • Solid state storage devices include:
      • PC cards
      • Flash memory cards
      • Smart cards
    • Corporations develop enterprise storage systems for their information storage needs.
    Chapter 4 Summary cont. NEXT SLIDE
  • 36. THE END