计算机专业英语--Computer Secondary Storage
计算机专业英语--Computer Secondary Storage
Computer Secondary Storage Computer storage is the holding of data in an electromagnetic form for access by a computer processor. Primary storage holds data in random access memory (RAM) and other "built-in" devices. In addition to RAM , primary storage includes read-only (ROM). Secondary storage retains data on hard disks ,tapes ,and other external devices such as diskettes and CD-ROMs Primary storage is much faster to access than secondary storage because of the proximity of the storage to the processor or because of the nature of the storage devices. On the other hand ,secondary storage can hold much more data than primary storage . The following are examples are examples of secondary storage units found in most computers. The Hard Disk Drive (HDD) is the machanism that controls the positioning ,reading and writing of the hard disk .The hard disk is the main secondary storage device used to permanently store information and consists of one or more magnetic disks contained in a box . An important function of a hard disk is to store program files and data files .Today's computers typically come with a hard disk that contains several billion bytes(gigabytes) of storage . A Floppy Disk Drive (FDD) is a removable storage device that reads and writes information magnetically onto floppy diskettes. The term "floppy" refers back to the 5.25' diskette that was actually soft and flexible. The 3.5' diskettes that we use today have a hard plastic exterior shell in order to protect the thin ,flexible disk inside. A HDD is mounted inside the system unit and only removed for repairs or upgrades. The FDD provides removable storage ,giving users the ability to take their files with them .The drawback to the floppy diskette is that is only holds 1.44 Mb of information. This is plenty of space for most text documents(Word and Excle files), but for files containing graphics ,a floppy capacity may be insufficient . A CD-ROM Drive is a secondary storage device that reads information stored on a compact disc . While floppy and hard disks are magnetic media ,the CD-ROM is an optic media .Magnetism can simply fade away in time ; however ,the life span of optic media is counted in tens of years ,which makes CD-ROM a very useful tool for archiving data . A CD-ROM can hold 640Mb of data .CD-ROM drives can be housed inside the computer case (internal), or connected to the computer by a cable(exterior). The most important specification for a CD-ROM drive is its speed ,how fast the disc will spin .The faster the disc spins ,the faster the data can be transferred to the computer memory .The CD-ROM 's speed is indicated with an "x" after it .For example,a twenty-four speed CD-ROM is labeled as a 24x .The larger the number ,the faster the disc can spin ,Most new computer systems today come with a 52x CD--ROM drive , and more and more have a DVD option.
http://dongfuzhang.spaces.live.com/blog/cns!6e30f05aa17cefa7!216.trak
Computer Secondary Storage Computer storage is the holding of data in an electromagnetic form for access by a computer processor. Primary storage holds data in random access memory (RAM) and other "built-in" devices. In addition to RAM , primary storage includes read-only (ROM). Secondary storage retains data on hard disks ,tapes ,and other external devices such as diskettes and CD-ROMs Primary storage is much faster to access than secondary storage because of the proximity of the storage to the processor or because of the nature of the storage devices. On the other hand ,secondary storage can hold much more data than primary storage . The following are examples are examples of secondary storage units found in most computers. The Hard Disk Drive (HDD) is the machanism that controls the positioning ,reading and writing of the hard disk .The hard disk is the main secondary storage device used to permanently store information and consists of one or more magnetic disks contained in a box . An important function of a hard disk is to store program files and data files .Today's computers typically come with a hard disk that contains several billion bytes(gigabytes) of storage . A Floppy Disk Drive (FDD) is a removable storage device that reads and writes information magnetically onto floppy diskettes. The term "floppy" refers back to the 5.25' diskette that was actually soft and flexible. The 3.5' diskettes that we use today have a hard plastic exterior shell in order to protect the thin ,flexible disk inside. A HDD is mounted inside the system unit and only removed for repairs or upgrades. The FDD provides removable storage ,giving users the ability to take their files with them .The drawback to the floppy diskette is that is only holds 1.44 Mb of information. This is plenty of space for most text documents(Word and Excle files), but for files containing graphics ,a floppy capacity may be insufficient . A CD-ROM Drive is a secondary storage device that reads information stored on a compact disc . While floppy and hard disks are magnetic media ,the CD-ROM is an optic media .Magnetism can simply fade away in time ; however ,the life span of optic media is counted in tens of years ,which makes CD-ROM a very useful tool for archiving data . A CD-ROM can hold 640Mb of data .CD-ROM drives can be housed inside the computer case (internal), or connected to the computer by a cable(exterior). The most important specification for a CD-ROM drive is its speed ,how fast the disc will spin .The faster the disc spins ,the faster the data can be transferred to the computer memory .The CD-ROM 's speed is indicated with an "x" after it .For example,a twenty-four speed CD-ROM is labeled as a 24x .The larger the number ,the faster the disc can spin ,Most new computer systems today come with a 52x CD--ROM drive , and more and more have a DVD option.
http://dongfuzhang.spaces.live.com/blog/cns!6e30f05aa17cefa7!216.trak
