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Storage device

Storage device

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Storage device

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  1. Storage device

  2. Backup storage Secondary storage

  3. Storage devices Storage device or backup device is used to store data and programs that are needed to be used again and again; e.g. Floppy, hard disks, CDs are often used as backing storage as well.

  4. Type of secondary storage device • Magnetic storage devices • Optical storage devices • Semiconductor backup devices

  5. Magnetic storage devices • Hard disk • Floppy disk • Zip drive • Magnetic tape

  6. Hard disk

  7. Hard disk • Advantages • Main backing storage of files and programs • Can store a lot of data compared to floppy disk • Can have a second hard disk as Back up storage • Disadvantages • Slow to access data when compared to RAM • Data can be damaged if the head crashes onto the platter

  8. Floppy disk

  9. Floppy disk • Advantages • Small, thin and lightweight, so easy to carry around • Can be reused. But data can not be overwritten only deleted to create space • Disadvantages • Can not store that much e.g one big picture will take up a lot of space of the entire floppy • It is thin so it can be damaged easily

  10. Zip disc/disk

  11. Zip disk/disc • Advantages • Can hold more data tha a floppy disk • Easy to carry around because of the size • Disadvantages • Much more expensive than a floppy • You can need a special drive to read the disk

  12. Magnetic Tape

  13. Magnetic Tape • Advantages • Can store a lot of data • Not easily damaged • Can be used overnight to back up a system • Disadvantages • Takes a long time to load data onto it • Have to go through the tape to get the data you want (cf serial access)

  14. CD ROMCD R/WDVD Optical storage

  15. CD - Rom • Advantages • Data can not be erased-you can not loss your data • Easy to carry around • Cheap to produce • Can be read by a DVD drive • Disadvantages • Fragile • Can scratch easily-this affects the data when the laser reads it • Slower to access than a hard disk

  16. CD - RW • Advantages • Data can be erased-it is possible to reuse it • Data can be updated – data can be rewritable again • Easy to carry around • Cheap to produce • Ca be read by a DVD drive • Disadvantages • Fragile • Can scratch easily-this affects the data when the laser reads it • Slower to access than a hard disk

  17. DVD • Advantages • Can store large amount of data • Does not transmit virus • Good for storing films and videos • The prices are getting cheaper • Disadvantages • Does not work in CD ROM drives • More expensive than CD ROMs

  18. Semiconductor/ Solid state storage devices e.g. Flash disk

  19. Flash disk Data is stored by charging small-scale “batteries” on the device Most flash disks have a capacity of 256 Megabytes up to 8 Gigabytes