Notifications for Display DevicesΒΆ
Display devices may need to know about external, asynchronous events. In order to accommodate that, the following notifications are defined.
The event number is standardized because the event will be handled by the OS directly under certain circumstances (see _DOS method in this specification).
These notifications are valid for Display Devices
Table B-4: Notifications for Display Devices
Value |
Description |
|---|---|
0x80 |
Cycle Output Device. Used to notify OSPM whenever the state of one of the output devices attached to the VGA controller has been switched or toggled. This event will, for example, be generated when the user presses a hotkey to switch the active display output from the LCD panel to the CRT. |
0x81 |
Output Device Status Change. Used to notify OSPM whenever the state of any output devices attached to the VGA controller has been changed. This event will, for example, be generated when the user plugs-in or remove a CRT from the VGA port. In this case, OSPM will re-enumerate all devices attached to VGA |
0x82 |
Cycle Display Output Hotkey Pressed. Used to notify OSPM whenever the user has pressed the Cycle display hotkey. |
0x83 |
Next Display Output Hotkey Pressed. Used to notify OSPM whenever the user has pressed the Next display hotkey. |
0x84 |
Previous Display Output Hotkey Pressed. Used to notify OSPM whenever the user has pressed the Previous display hotkey. |