[ltp] Active Protection System

[Lenz Grimmer]

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Hi,

Jaime Iniesta wrote:
> Is the APS part of the hard drive? I mean, is it built in the HD?

Partly, the Hard Disk needs to support the proper ATA command ("idle
immediate unload" to park the head.

> I'm planning of installing Linux on another hard drive I have, not on
> a partition on the original drive. So I wonder if the APS that comes
> with the R52 will work also with that other hard drive.

No, it won't - it depends on the running OS.

Several components are involved here. There is an accelerometer that
measures if the laptop is in motion. There now is an early version of a
Linux kernel driver available on http://hdaps.sourceforge.net/ that
allows applications to read out these acceleration values. However,
there currently is no code available that actually takes proper action
in case these values indicate a severe condition (like free fall). So
currently, there is only partial support for what's known as the APS on
Windows. What's missing is a *reliable* way to park the hard disk head
and keep it parked (some sample code exists, but it does not seem to
work for all drives). Oh, and the code that actually makes the decision
if the accelerometer readings indicate that it's time to park the heads...

Bye,
	LenZ
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 Lenz Grimmer <lenz@grimmer.com>                             -o)
 [ICQ: 160767607 | Jabber: LenZGr@jabber.org]                /\\
 http://www.lenzg.org/                                       V_V
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