Construction and Operation of the Hard Disk

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Construction and Operation of the Hard Disk

• By Mark Beltran(Sir Marcus Aurelius Beltraneus
  The Medieval Maniac)

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Components of the Hard Drive
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Hard Disk Operational Overview

• Uses platters to store information
• Platters mounted on a spindle
• Rotate at high speeds
• Read/write heads used to read and record data
• Arms are positioned by actuator
• Logic board communicates with the rest of the PC

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Platters

• Each platter has two heads
• Por ejemplo 3 platters 6 heads
• Each platter surface holds tens of billions of
  individual bits of data
• Info is recorded on tracks
• Tracks are divided into sectors
• Sector 512 bytes

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Hard Drive Diagram
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Steps to accessing the Hard Disk

• Figure out where on the disk to look for
  information
• Location of the disk addressed by its geometry
• Hard Disks control program checks the internal
  buffer (cache)
• Controller board activates spindle motor to spin
  up drive to operating speed

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Steps to accessing the Hard Disk (cont.)

• Controller board interprets address/ Moves read
  write heads to appropriate track
• Activates the appropriate read/write head and
  reads the contents of the sector
• Controller board coordinates flow of information
  from hard disk to buffer
• Sends information to system memory, satisfying
  the systems request for data