On Thu, Oct 12, 2000 at 10:12:42AM -0400, Trei, Peter wrote:
Yep. Most laptops have a video card for attaching an external monitor, with an unshielded port - they thus spray out monitor-driving RF signals while they run, regardless of whether there is a monitor out there to receive them.
Of course, a *good* laptop design would power off the video card if it's not in use, to extend battery life if nothing else. I don't know if they do this.
All the laptops I've used in the last 6 years (IBM, Compaq, Dell) have had built-in hotkeys to switch from LCD, LCD+CRT, CRT. Monitors attached to the VGA port while the laptops were in LCD-only mode consistently blinked their messages for "No video source". APM (which virtually all current PCs support) allows for monitor blanking, suspend, and powerdown. XFree86 and Windows support these functions. -dsr-