IBM
Hard
Drive
Active
Protection
System
The
IBM
®
Hard
Drive
Active
Protection
System
helps
to
protect
your
hard
disk
drive
when
the
shock
sensor
inside
your
ThinkPad
®
computer
is
enabled
and
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
®
XP
or
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
1
