Compaq Armada V300 Series Reference Manual page 45

Press to adjust the brightness of the computer screen
with an on-screen slide button or with the arrow keys.
Press to display information about system hardware
components and software version numbers.
The number beside System BIOS is the version number of
your system ROM.
When the computer is running MS-DOS under Windows and the
desktop area resolution is set lower than the display resolution,
press to toggle the image between Text Stretch, which
stretches the text to fill more of the screen, and not stretched. Text
Stretch is the default.