The asus driver provides support for hotkeys available
  in various ASUS laptops and netbooks (Eee PC series included).
The following hotkeys are directly handled by
    asus:
  - Fn + F3
- Decrease LCD brightness
- Fn + F4
- Increase LCD brightness
- Fn + F5
- Switch between LCD and external video output
- Fn + F7
- Toggle audio
- Fn + F8
- Volume down
- Fn + F9
- Volume up
 
The asus driver appeared in NetBSD
  5.0.
The asus device driver was written by
  Jared D. McNeill. This man page was written by
  Leonardo Taccari.
At the moment asus does not handle Fn + F6 (Task
  manager).