Ibm Hard Drive Active Protection System; Ibm Active Protection System Design - Lenovo ThinkPad T41 Manual

IBM Hard Drive Active Protection System

The IBM
drive when the shock sensor inside your ThinkPad
detects some situations that could potentially cause damage to your hard disk
drive. Difficulty with the hard disk drive often results from physical shock to the
hard disk drive. One type of physical shock, called operating shock, occurs when
the disk is in operation. During operation, the drive head is typically over the
drive platters reading and writing data. When a physical shock to the drive occurs
during operation, the head and the platters can come into contact causing both
components to be damaged. The second type of shock, called non-operating shock,
occurs when the head is in the unloaded position, or not positioned over the
platters. When a physical shock occurs in the non-operating state, the head can
contact the ramp it is positioned over and damage the ability of the head to read
and write data to the hard disk drive. IBM has focused on two rating values for
the amount of shock and vibration generally required to cause damage in each of
these situations. The value for operating shock is 200G/2ms and the value for
non-operating shock is 800G/1ms for a typical 2.5" hard disk drive. These values
suggest that by using this technology the hard disk drive is four times better able
to withstand a shock, and hence more durable if the head is unloaded prior to
receiving an excessive shock. The following information describes the design and
implementation of this technology.
Note: The IBM Hard Drive Active Protection System protects only the primary
hard disk drive on select ThinkPad computers using Microsoft
Windows 2000. The protection system does not support protection of any
secondary hard disk drives, including those installed in an UltraBay drive bay. The
active protection system functions only with the 2.5" hard disk drive provided by
IBM due to special customization.

IBM Active Protection System Design

The active protection system works to minimize the risk that your hard drive
could be damaged by moving the read/write heads of the hard disk drive to areas
that do not contain data when the shock sensor detects computer tilt, vibration, or
shock. There are two types of hard disk drives. The first spins down the motor
after unloading the head. The second does not spin down the motor, but does
unload the head. The hard disk drive is less vulnerable to damage when it is not
in operation. Since the hard disk drive cannot be accessed while the head is
unloaded, it may seem to the user that the drive has stopped. In reality, the disk
access request has been temporarily suspended at the disk driver position so that
the disk head can remain unloaded until a stable situation is detected. The
suspended disk access request is then released and passed to the disk and the hard
disk drive resumes normal operation.
The active protection system uses a combination of hardware and software
components. The hardware component is a motion detector, or accelerometer,
embedded in the motherboard which continually senses system orientation and
movement. The software component receives and interprets signals from the
accelerometer, differentiates between potentially harmful movements and repetitive
motion, and signals the hard drive to stop when a potentially damaging event is
predicted. The software component also includes a system tray icon and properties
window.
© Copyright IBM Corp. 2003
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Hard Drive Active Protection System helps to protect your hard disk
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computer is enabled and
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Windows XP or
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