disk80 tracks side 18 sectors track 512 bytes sector 1474560 Bytes disk 147 MB

Disk80 tracks side 18 sectors track 512 bytes sector

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/ disk)(80 tracks / side )(18 sectors / track )(512 bytes/ sector ) =1,474,560 Bytes/ disk 1.47 MB Store data using Longitudinal Recording or Perpendicular Recording Computing capacity Multiply number of sides, # tracks, # sectors per track, # bytes per sector For high density disk: 2 sides x 80 tracks x 18 sectors per track x 512 bytes per sector=1,474,560 bytes The hard disk arms move the read/write head, which reads items and writes items in the drive Location is often referred to by its cylinder Head crash occurs when read/write head touches surface of platter Always keep backup of your HD
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RAID is a group of two or more integrated HD’s Main benefit is availability of storage Secondary is improved performance NAS is server connected to network with sole purpose of providing storage Disk controller consists of special purpose chip and electronic circuits that control transfer of data, instructions, and info from disk to and from the system bus and other components of computer SATA EIDE SCSI SAS Hard Disks vs Disk Cache Portion of RAM memory that processor uses to store frequently accessed items 1 st request for data goes to disk cache 2 nd request goes to HD Memory cards and USB Flash Drives (storage) Digital photos or files to be transported Optical disks Software, movies, music Consists of flat, round, portable disk made of metal, plastic, and lacquer that is written and read by a laser Typically store software, data, digital photos, movies, music Read only vs rewritable How a laser reads data on optical disk:
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1. Laser diode shines light beam toward a disk 2. If light strikes a pit, it scatters, if light strikes a land, it reflects back toward laser diode 3. Reflected light is deflected to a light sensing diode, which sends a digital signal of 1 to the computer.
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  • Fall '12
  • YvonneGalusha
  • Flash memory, Optical disk, Memory card

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