Hardware Reference
In-Depth Information
Theplatters,spindlemotor,heads,andheadactuatormechanismsusuallyarecontainedin
a sealed chamber called the
head disk assembly
(HDA). The HDA is usually treated as a
singlecomponent; itisrarelyopened.Otherpartsexternal tothedrive'sHDA,suchasthe
logic boards, bezel, and other configuration or mounting hardware, can be disassembled
from the drive.
Note
Very old hard disks (those made in the 1980s until the early 1990s) used oxide media and
stepper motors, but these technologies are no longer used by the hard disks you are likely to
encounter.
Components” of
Upgrading and Repairing PCs, 19
th
edition
, included in its entirety on the
DVD packaged with this topic.
Hard Disk Platters (Disks)
AnHDDhasoneormoreplatters,ordisks.HarddisksforPCsystemshavebeenavailable
in several form factors over the years. Normally, the physical size of a drive is expressed
as the size of the platters.
Table 9.9
lists the platter sizes that have been associated with
PC HDDs.
Table 9.9 Hard Disk Form Factors Versus Actual Platter Sizes
