Active Protection System
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The Active Protection SystemWith the new series of Thinkpads IBM introduced the Active Protection System (APS) in 2003. The APS is a protection system for the Thinkpad's internal harddrive. A sensor inside the Thinkpad recognizes when the notebook is accelerated. A software applet then is triggered to park the harddisk. This way the risk of data loss in case of when the notebook is dropped is significantly reduced since the read/write head of the harddrive is parked and hence can't crash onto the platter when the notebook drops onto the floor. The whole concept of the technology seems very advanced. For the first part, the hardware sensor is capable of not only recognizing acceleration of the notebook, but also (to a certain degree) of its whole orientation in space, relative to gravity's axis. Furthermore, having the actual control put into software, its functionality is extendable and it gives chance to implement features like the "ignore minor shocks" feature which is present in the Windows based control applet. (This feature prevents the harddrive from parking in case of minor regular shocks such as occur when in a train or car.) |
Linux Support
Linux support is so far not available.
Note that this feature definitely depends on software and there is no hardware or BIOS only way of making it work. A statement from IBM clearifies this: "The APS system will require APS software to be installed on the computer before it activates the harddrive parking . This means it will not work on systems preloaded with Linux."
However, IBM made general (unofficial) statements that they are willing to release the specifications of the hardware sensor and its API to the linux community or some developers, but they in fact, never did. Also some linux developers actively tried to contact with IBM about the issue but were unable to make progress.
| Date | User | effort made | result |
|---|---|---|---|
| March 2004 | Wyrfel | asked IBM representatives at CeBIT 2004 about state of linux support | got promise that specifications will be released, but nothing actually happened |
| May 9th, 2004 | Sam Hocevar | Wrote to the IBM France Linux Marketing Program manager about who to contact to get specs | email was forwarded on May 10th to to at least 6 additional IBM people, but no answer so far |
Related Links
- Quoted from NewScientist.com: The latest Apple PowerBook laptops can be controlled with a gentle shake. Programmer Amit Singh has written code that lets him use the sensor to control software on the computer. The code is published at www.kernelthread.com/software/ams/.
- There is a fairly detailed article about reverse engineering the APS accelerometer interface by Mark Smith from IBM Research. Apparently they even have a prototype Linux driver working, but cannot release the full source yet.
- There is a mailing list dedicated to developing & testing a kernel module and a user space application. More info on this mailinglist and the archive at https://lists.sourceforge.net/lists/listinfo/hdaps-devel.
- You can find some of the coders working on this module on irc.freenode.org in #hdaps
