Chapter 04


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  • A hard drive stores program files and data files. Data files can be almost anything; help files, support files, letters, contracts, accounting journals, etc..
  • Also called a fixed disk. Resides in an internal drive bay. Requires a power connector and a data connector. Older parallel drives: (Now called PATA) Really Old: 40-wire ribbon connector Newer Old: 80-wire ribbon cable Both were stiff, cold, short, and could block airflow IDE/ATA; Integrated drive Electronics/AT Attached (AT= Advanced Technology. From the IBM PC AT, 1982) Anything with IDE, EIDE, AT, ATA, DMA, Ultra DMA, or ATAPI in the name Max transfer rate about 133 MB/sec Newer Serial Drives: (Now called SATA) PCI-e, serial connection Seven-wire connector; Thinner, longer, and more flexible 1 st Gen=150 MB/sec; 2 nd Gen=300 MB/sec; Roadmap leads to 600 MB/sec Most physical drives are barely fast enough to saturate the 150 MB/sec 1 st Gen
  • PATA on the Left SATA on the Right
  • Typical Hard Drive Configuration
  • Disks are called Platters. Typical drives have three platters. Each side of a platter is called a surface.
  • The actuator assembly moves the read/write heads.
  • There is one read/write head for each surface.
  • Spinning platters write data in concentric circles called Tracks. The yellow is a track. Tracks are numbered starting from zero at the outermost track. Tracks are further subdivided into segments of arc called Sectors. The blue is a sector. Each sector in a drive holds 512 Bytes. Notice the outer sectors are physically longer than the inner sectors, but still hold 512 Bytes. Most drives since the early 1990s use Zone Bit Recording that sets the sector length so that there are more sectors on the outer tracks. The sector that would be sector zero, is called the Master Boot Record. Therefore, the first usable sector is numbered sector 1, again on the outer track. Zone bit recording From Wikipedia, the free encyclopedia Zone Bit Recording ( ZBR ) is used by disk drives to store more sectors per track on outer tracks than on inner tracks. It is also called Zone Constant Angular Velocity ( Zone CAV or Z-CAV or ZCAV ). On a disk consisting of concentric tracks, the physical track length increases with distance from the center hub. Therefore, holding storage density constant, the track storage capacity likewise increases with distance from the center. To implement ZBR, a drive's controller varies the rate at which it reads and writes - faster on outer tracks. Alternatively, the disk rotation rate could be slowed, as was done by the original Apple Macintosh floppy disk .
  • Code Area: Master boot program that calls the OS boot record. Table of primary partitions: Contains partition information about the hard disk. A single hard drive can be divided into a number of drive letters. A single hard drive can contain more than one operating system. If it does, they cannot generally communicate with each other. It’s like having more than one computer in one computer. Each of these entities would be contained in a separate drive partition.
  • Hard drive capacities have reached one terabyte for internal drives. External drives can be connected through a USB port, or through a firewire port. Large capacity hard drives are especially important for people who work with large graphic files and video. A one-hour mini DV video tape can be a 20 GB download onto your hard drive. Editing it would require a second file of at least equal size. Hi-Def would be larger.
  • The most important word in computing is backup. Many external hard drives come with software that will automatically back up your PC’s main hard drive. Archiving is saving old computer data files that you may someday, but probably never, need.
  • A certain percentage of hard drives fail each year. If yours is one of them, and your PC is not too old, it may be cost efficient to replace the old, dead drive with a new one. Remember, you’ll need OS installation media.
  • Copy old and rarely used files from computer to external storage. You can free up hard drive (HD) storage. External HD is helpful
  • Internal HD is less expensive than external drive, but more difficult to set up. All computers usually have at least one internal HD. Fit into bays in case. Connect through ATA (Advanced Technology Attachment) see earlier slides.
  • Connects to machine either in front or back. Often USB connect or somethings FireWire connection. Takes up desk space. Moveable to other computers.
  • Hard drive storage capacity is measured in gigabytes (GB), or terabytes (TB) these days. The larger the HD the better. One hour DVD-quality video takes about 2 GB of HD space.
  • Most desktop hard drives spin at 7200 RPM. Drives are available that spin at 10,000 and 15,000 RPM, but they are very pricey. (RPM means revolutions-per-minute. ) Most laptop drives spin at 5400 RPM. That’s one reason laptops typically seem to operate more slowly than an equivalently equipped desktop. Average access time is the average time it takes for the read/write heads to locate the sector to be accessed. Average access time is measured in milliseconds, typically around 8ms. The lower the average seek time, the faster the HD finds data.
  • The word “cache” means a store of things that will be required in the future. In computing, it is a memory storage area used by fast devices to access data stored in slower devices. Disk cache is a memory area, now part of the disk drive itself, that stores the most recently used data and instructions retrieved from the drive. During the next access, the drive will look in the cache memory for the requested data. If it is there, the transfer will be thousands of times faster than if the drive itself has to be accessed. A cache is also called a “buffer”. The HD cache is usually 2, 8, or 16 MB.
  • Creating more space on HD, means doing cleanup. You should have at least 25% free space. Deleting unwanted files, Internet histories, and cookies can free up space on your hard drive. You can always burn them to CD or DVD, if you feel you just can’t part with them completely. You don’t delete programs in Windows, you uninstall them. You can always reinstall them, if you have the original install disks. Also, delete programs you no longer use. You can keep the installations disks so if you want them later you can reinstall. Often you use an uninstall program to remove programs. Check first. Also, remember to empty the recycle bin after doing deletions.
  • Remember, saving old stuff is also called archiving. Can save/archive to CDs, DVDs, Tape cartridges or an external HD.
  • Windows Backup: Start/All Programs/Accessories/System Tools/Backup Google backup programs, and get a bunch. There are many different backup programs available. You can also back up stuff to an Internet site for a fee., among others. Back up the data files often to external media just to be sure you have it. Full Backup means everything. Incremental Backup means backing up only those files that have been changed since the last backup. Can set up automatic back up to run. Don’t need to back up programs because you should still have the original install media so you can reinstall. Store your backup off site.
  • A virus is a program intended to do damage to your PC. Viruses are transmitted through infected e-mails, downloads, floppy disks, CDs, DVDs, Flash Drives, hackers that can access your PC while you’re on-line without you knowing it, or anything else that has been infected that you connect to your PC. Your PC should be protected with a complete set of programs that include a firewall, virus scanner, and anti-spyware at the least. Some anti-virus programs: Norton AntiVirus, McAfee VirusScan. You need to update the virus scan data file often. Can be set to automatically update. Popular software names are Norton, McAfee, ZoneAlarm, Kasperski, AVG, and others.
  • Fragmentation happens whenever your PC is turned on. Parts of files get spread apart. The read/write heads have to work harder to read and write. Your drives will wear faster, and the probability of losing data on your drive increases. Defragmentation puts file pieces back together. Windows: Start/All Programs/Accessories/System Tools/Disk Defragmenter
  • Parts of hard drives have errors when they are manufactured. These are mapped out by the formatting program, So the operating system can’t use them. Other parts of drives may fail during use. Check your drives periodically For errors. Most Operating Systems (OS) include a HD repair program. Ex. ScanDisk or Check Disk programs.
  • A second hard drive can allow you to install your software on your primary drive, and use your secondary drive For data storage. That helps increase efficiency.
  • CD-ROM: Compact Disc Read-Only-Memory; Half-life app. 30 years Created by the vendor – not recordable 120 mm diameter (App. 4 5/8 in.) Data are read by a laser beam: Pits and Lands: Pits are holes burned into the subsurface, Lands are the flat surfaces; A pit is a zero, a land is a one. Sampling rate is 44.1 KHz; Derived from TV video scan lines CD-ROM drive reads and some times writes information to and from a CD-disc Most CD drives are internal but some are connected to the computer by a cable externally
  • Most program installation disks today are on CD-ROM
  • The rise of CD music popularity is being eclipsed by the MP3 movement.
  • Vast amount of reference material on the CD format Beyond music there are encyclopedia, atlas, dictionary, guide, exam preparation, etc.
  • The x in CD-ROM speeds stands for a transfer rate of 150 KB/sec. 52x means 52 times 150 KB/sec
  • CD-ROM storage Originally 650 MB for 74 minutes of music; Currently 700 MB for 80 minutes of music; Good for storing photos. video, animations, music and other large files.
  • Care and handling of CDs; By the edges; Don’t scratch the disc – Top or Bottom! Store in protective cover; Don’t get them hot, especially in direct sunlight through a window. Melt time!
  • CD-R: CD-Recordable; Multi-session – can add to disc, but can’t erase CD-RW: CD-Rewritable – can erase and re-record A CD burner can perform all the same functions of a CD-ROM drive.
  • Roxio and Nero are two popular burning programs Including music Can store up to 700 MB (up to 80 min. or 10 hr MP3 songs) currently on a single recordable CD. CR-RW drives allow you to create your own CDs, and often come with software to make recordings. Sometimes discs make on one drive might not be able to be read on another.
  • Type of CD-RW drive Internal drives require a data cable and a power cable. placed into a drive bay like hard drives etc., generally less expensive than external drives, but more difficult to set up.
  • Type of CD-RW drive External drives require a USB port and a power outlet for the drive Power Source Unit(PSU). Can be moved to other computers
  • Typical speed ratings are 48x32x52. Read Speed x write speed on CD-RW x speed drive records data on a CD-R The largest number is the read speed. The middle number is the CD-R write speed. The smallest number is the CD-RW write speed. Purchase CDs to match drive speed A CD-RW drive can record data on a CD-R (Compact Disc-Recordable) only once, A CD-RW drive can erase and re-record data on a CD-RW (Compact Disc-ReWritable) hundreds/multiple of times.
  • Combo drives combine the features of all three CD-RW drives and DVD-ROM drive into a single drive. It is cheaper than the individual drives, but if one part fails, they all probably fail. Copying CDs and DVDs is better with two drives. Reads CDs, DVDs and record to CDs.
  • DVD – Digital Video Disc; Renamed to Digital Versatile Disc (Why?) - Officially when announced it was called DVD and no definition was provided. - Changed to Digital Versatile Disc from Digital Video Disc, because it also had non-video applications, s Roughly seven times the storage ability of CDs. (4.7 GB) Same disc size as CD stores 6 times the information. Most are internal drives. 133 minutes of graphics and sound; 95% of Hollywood’s movies. On any given day, there are roughly ten different DVD recording formats. The most popular for PCs are + and – R and RW
  • DVD-ROM Drive Applications DVD drives play and record all lower levels of optical media that are designed to work with a PC. Including games, movies, music, phone directory etc. CDs can be played on DVD drives. DVD-ROM play DVD-Video discs, which hold >2 hrs of full-length movies. Most have a menu system.
  • DVD-ROM Drive Applications Because the discs all rotate at the same constant linear velocity, the speed factors in DVDs are roughly seven to nine times those in CDs. Current DVD-ROM drives commonly have speeds of 16x. Handle DVDs like CDs, by edges, avoid scares, etc. Combo drive similar to previous material. Takes up less space than the individual items.
  • Most burners will match the maximum rate of burn to the maximum rate that your media can tolerate. Can buy DVDs rated at different speeds, ie 8x. Buy to match device. DVD+/-RW drives allow you to record DVDs. DVD+/-RW stands for Digital Versatile Disc+/-ReWritable. Can record and erase. Also called a burner.
  • Don’t write on the CD or DVD with a regular pen or pencil. There are special markers. Better yet, Use a label maker program, and print your own labels. Scratching the label side can cause the laser to read errors.
  • Blue-laser DVD new type drive. Ideal playing and recording high-definition video, like movies. Use blue-laser (which is shorter than other colors), instead of red-laser to read/write. Blue laser stores data more densely on disc, therefore higher storage capacity. 2 main standards: Blu-ray is 25 GB single-layer; 50 GB double-layer – Sony original release 2006 HD-DVD is 15 GB single-layer; 30 GB double-layer – Toshiba standard originally, in 2008 they said they would move to Blu-Ray as standard.
  • Blu-ray Disc was developed by the Blu-ray Disc Association , a group of companies representing consumer electronics, computer hardware, and motion picture production. The standard is covered by several patents belonging to different companies. As of March 2007, a joint licensing agreement for all the relevant patents had not yet been finalized. [2] During the high definition optical disc format war , Blu-ray Disc competed with the HD DVD format. On February 19 , 2008 , Toshiba  — the main company supporting HD DVD — announced it would no longer develop, manufacture and market HD DVD players and recorders, [4] leading almost all other HD DVD supporters to follow suit, effectively naming Blu-ray the victor of the format war. As of April 5 , 2008 , more than 530 [3] Blu-ray Disc titles have been released in the United States , and more than 250 in Japan .
  • Memory card readers read various types of memory cards and microdrives. Many new PCs come with multi-card readers. Most others offer them as a low-cost option. Memory cards used in digital camera, MP3 players, PDAs, and some cell phones Can be internal or external. External easier to set up and portable.
  • Flash memory Several Formats Low power requirements Non-volatile storage AKA, memory card, flash card. No external power required. Memory holds for long time without power or computer
  • Different types of memory cards made by different manufacturers and designed for different devices. Popular cards: CompactFlash, Memory Stick, Micro Drive, MultiMedia Card, Secure digital, SmartMedia and XD-Picture cards
  • Flash Memory Card Sony October 1998 Current Maximum – 16 GB Maximum potential memory capacity – 32 GB Name given to family of memory sticks
  • Microdrive 1999 by IBM Compact Flash Type 2 form factor 8 GB current capacity Hitachi promised a 20 GB version 2007 – Haven’t seen it yet.
  • Hitachi 3K8 Compact Flash Drive – 6 GB
  • MultiMediaCard (MMC) Smaller than Compact Flash – About the size of a standard postage stamp Being superseded by Secure Digital Cards, and can go in many SD Card slots Up to 4 GB
  • Secure Digital Memory Card 1999 collaboration of Matsushita (Panasonic), SanDisc, and Toshiba 8 MB to 16 GB 4 GB to 32 GB called Secure Digital High Capacity (SDHC) Developed as an extension of the MMC standard
  • SmartMedia Card 1995 – original flash memory card, now obsolete
  • xD card Competitor to SD card Slower than SD Card; More expensive than SD card Maximum to 8 GB capacity
  • Flash memory is more durable than many other types of storage media More Durable than other types of storage media no moving parts Avoid extreme heat , cold, or humidity
  • Can transfer data easily between computers and digital devices. Ex. mem. card from camera can be read on computer. can transfer without a computer Ideal to transfer medium-sized files etc
  • Removable storage Can use new cards to increase storage size can use to transfer to desktop
  • many different types of memory card readers. can have one or more slots to read one or more types of cards Before purchase check to see which cards you need to read.
  • light weight storage device small size Called USB (Universal Serial Bus), key drive, memory key, thumb drive, jump drive
  • Connect to USB Port on computer It is automatically recognized as an additional hard drive, it is assigned a drive letter Can use like any other drive, save and read files to it Park the drive before removal!!!!
  • plug in directly to USB port or through cable or hub does not require additional power data can remain on drive for 10 or more years without connection to power supply or battery Rewritable media
  • ideal for storing small to medium-sized files up to 16 GB storage capacity fast transfer between drive, and other storage device Faster than other removable storage
  • Devices that are combination of flash drive and MP3 player Features of flash drive but can store and play MP3 songs Similiar to IPOD
  • Provide security because you take data with you rather than leave on computer Some have built in security features, that is password protected
  • Can move between computers. like work and home to continue working. Some people email files to have at other location, this can be used for same. Email has size limits which are larger with Flash drive.
  • Tape Drives: -Internal or external -external more expensive, easier to set up and can be moved between multiple computers Tape cartridges used to store information, need to be kept in cool, dry play away from electrical equipment tapes cheap but not as common anymore - flash drive, CDs, DVD and portable Hard Drive used more often Left Used for backup Backup programs or come with operating system or drives RIGHT Archive Data can copy old or rarely used files from computer to tape cartridges then free up storage
  • Tape drive can compress or squeeze data together when backing up or archiving Compressing can double amt of data stored Compressing method depends on type of drive
  • DDS (Digital Data Storage) Use DAT (Digital Audio Tape) 5 types of DDS drives DDS 1, DDS2, DDS 3, DDS 4 & DDS 5 Larger the number more data and faster store up to 36 GB(72 GM compressed) AIT (Advanced intelligent Tapes) several types AIT 1, AIT 2, AIT 3 larger number more data and faster stores up to 100 GB (260 GB compressed) LTO (Linear Tape Open) 2 types: LTO 1 & LTO 2 larger number more data and faster transfer rate store up to 200 GB (400 GB compressed) on single tape DLT (Digital Linear Tape) variety of storage capacities can store up to 300 GB (600 GB compressed) on single tape.
  • Chapter 04

    1. 1. Chapter 4 Storage Devices Maran Illustrated Computers CIS 102
    2. 2. Contents What is a hard drive? What is the difference between a CD-ROM drive and a CD-RW drive? Why would you use a flash drive? Learn about storage devices in this chapter . <ul><li>Hard Drive </li></ul><ul><li>Floppy Drive </li></ul><ul><li>CD-ROM Drive </li></ul><ul><li>CD-RW Drive </li></ul><ul><li>DVD-ROM Drive </li></ul><ul><li>DVD+/-RW Drive </li></ul><ul><li>Memory Card Reader </li></ul><ul><li>Flash Drive </li></ul><ul><li>Tape Drive </li></ul>
    3. 3. Hard Drive Contents 04/21/10 CIS 102 - Chapter 4
    4. 4. Hard Drive/Fixed Disk 04/21/10 CIS 102 - Chapter 4
    5. 5. Connector types <ul><li>PATA connector </li></ul><ul><li>SATA connector </li></ul>04/21/10 CIS 102 - Chapter 4
    6. 6. Hard Disk Drive 04/21/10 CIS 102 - Chapter 4
    7. 7. Platters 04/21/10 CIS 102 - Chapter 4
    8. 8. Actuator 04/21/10 CIS 102 - Chapter 4
    9. 9. Read/Write Head 04/21/10 CIS 102 - Chapter 4
    10. 10. Tracks 04/21/10 CIS 102 - Chapter 4
    11. 11. 04/21/10 CIS 102 - Chapter 4 Structure of a Master Boot Record Address Description Size in bytes Hex Dec 0000 0 Code Area max. 446 01B8 440 Optional Disk signature 4 01BC 444 Usually Nulls; 0x0000 2 01BE 446 Table of primary partitions (Four 16-byte entries, IBM Partition Table scheme) 64 01FE 510 55h MBR signature; 0xAA55 2 01FF 511 AAh MBR, total size: 446 + 64 + 2 = 512
    12. 12. More Storage 04/21/10 CIS 102 - Chapter 4
    13. 13. Back Up Data 04/21/10 CIS 102 - Chapter 4
    14. 14. Hard Disk Failure 04/21/10 CIS 102 - Chapter 4
    15. 15. Archive Data 04/21/10 CIS 102 - Chapter 4
    16. 16. Internal Hard drive 04/21/10 CIS 102 - Chapter 4
    17. 17. External Hard Drive 04/21/10 CIS 102 - Chapter 4
    18. 18. Storage Capacity 04/21/10 CIS 102 - Chapter 4
    19. 19. Speed 04/21/10 CIS 102 - Chapter 4
    20. 20. Cache 04/21/10 CIS 102 - Chapter 4
    21. 21. Remove Files & Programs 04/21/10 CIS 102 - Chapter 4
    22. 22. Archive Files 04/21/10 CIS 102 - Chapter 4
    23. 23. Tips for Backing Up 04/21/10 CIS 102 - Chapter 4
    24. 24. Protect Against Viruses 04/21/10 CIS 102 - Chapter 4
    25. 25. Defragment a Hard Drive 04/21/10 CIS 102 - Chapter 4
    26. 26. Repair Hard Drive Errors 04/21/10 CIS 102 - Chapter 4
    27. 27. Efficiently Store Data 04/21/10 CIS 102 - Chapter 4
    28. 28. CD-ROM Drive 04/21/10 CIS 102 - Chapter 4
    29. 29. CD-ROM Drive Application Install Program 04/21/10 CIS 102 - Chapter 4
    30. 30. Play Music CDs 04/21/10 CIS 102 - Chapter 4
    31. 31. Play Reference CD-ROM Discs 04/21/10 CIS 102 - Chapter 4
    32. 32. CD-ROM Drive Speed 04/21/10 CIS 102 - Chapter 4
    33. 33. Storage Capacity 04/21/10 CIS 102 - Chapter 4
    34. 34. Handle and Protect a Disc 04/21/10 CIS 102 - Chapter 4
    35. 35. CD-RW Drive 04/21/10 CIS 102 - Chapter 4
    36. 36. CD-RW Applications – Store & Transfer Files 04/21/10 CIS 102 - Chapter 4
    37. 37. Internal CD-RW Drive 04/21/10 CIS 102 - Chapter 4
    38. 38. External CD-RW Drive 04/21/10 CIS 102 - Chapter 4
    39. 39. Drive Speed & Recordable CD 04/21/10 CIS 102 - Chapter 4
    40. 40. Combo Drive 04/21/10 CIS 102 - Chapter 4
    41. 41. DVD-ROM Drive 04/21/10 CIS 102 - Chapter 4
    42. 42. Play DVDs and CDs 04/21/10 CIS 102 - Chapter 4
    43. 43. DVD-ROM Drive Speed 04/21/10 CIS 102 - Chapter 4
    44. 44. Recordable DVDs – Disc Speeds 04/21/10 CIS 102 - Chapter 4
    45. 45. Types of Recordable Disc <ul><li>DVD+/-RW records several types of recordable DVDs. </li></ul><ul><li>Can record: </li></ul><ul><ul><li>DVD+R (recordable) </li></ul></ul><ul><ul><li>DVD-R records only once </li></ul></ul><ul><ul><li>DVD+RW (ReWritable) or DVD-RW can erase and re-record hundreds of times </li></ul></ul><ul><li>DVD+R and DVD-R less expensive than DVD+RW or DVD-RW </li></ul>04/21/10 CIS 102 - Chapter 4
    46. 46. Disc Storage Capacity <ul><li>DVD can be single or double-sided </li></ul><ul><li>All DVD+/-RW can play and record on single and double-sided DVDs. </li></ul><ul><li>To record on double-sided you must flip over. </li></ul><ul><li>Can store 1 or 2 layers of data on each side </li></ul><ul><li>All DVD drive can play single and dual-layer discs, but need special dual-layer drive to record on dual-layer </li></ul>04/21/10 CIS 102 - Chapter 4
    47. 47. Disc Storage (cont.) <ul><li>The capacity is determined by single, double, single-layer, or dual-layer </li></ul>04/21/10 CIS 102 - Chapter 4 Single-Layer (SL) Dual-Layer (DL) Single-sides (SS) 4.7 GB 8.5 GB Double-sided (DS) 9.4 GB 17 GB
    48. 48. Protect a Disc 04/21/10 CIS 102 - Chapter 4
    49. 49. High-Definition Video 04/21/10 CIS 102 - Chapter 4
    50. 50. Blu-Ray
    51. 51. Memory Card Reader 04/21/10 CIS 102 - Chapter 4
    52. 52. What is a Memory Card? 04/21/10 CIS 102 - Chapter 4
    53. 53. Types of Memory Cards 04/21/10 CIS 102 - Chapter 4
    54. 54. Sony Flash Memory Cards 04/21/10 CIS 102 - Chapter 4 Lock
    55. 55. Microdrive 04/21/10 CIS 102 - Chapter 4
    56. 56. Hitachi Flash Drive 04/21/10 CIS 102 - Chapter 4
    57. 57. Multimedia Card (MMC) 04/21/10 CIS 102 - Chapter 4
    58. 58. Secure Digital Memory Card 04/21/10 CIS 102 - Chapter 4 Lock
    59. 59. Smart Media Card 04/21/10 CIS 102 - Chapter 4
    60. 60. xD card 04/21/10 CIS 102 - Chapter 4
    61. 61. Care and Handling 04/21/10 CIS 102 - Chapter 4
    62. 62. Data Transfer 04/21/10 CIS 102 - Chapter 4
    63. 63. Data Storage 04/21/10 CIS 102 - Chapter 4
    64. 64. Memory Card Reader 04/21/10 CIS 102 - Chapter 4
    65. 65. Flash Drive 04/21/10 CIS 102 - Chapter 4
    66. 66. How does it work? 04/21/10 CIS 102 - Chapter 4
    67. 67. Flash Memory 04/21/10 CIS 102 - Chapter 4
    68. 68. File Storage 04/21/10 CIS 102 - Chapter 4
    69. 69. MP3 capabilities 04/21/10 CIS 102 - Chapter 4
    70. 70. Security 04/21/10 CIS 102 - Chapter 4
    71. 71. File Transfer 04/21/10 CIS 102 - Chapter 4
    72. 72. Tape Drive 04/21/10 CIS 102 - Chapter 4
    73. 73. Compress Data 04/21/10 CIS 102 - Chapter 4
    74. 74. Types of Tape Drives 04/21/10 CIS 102 - Chapter 4