The Wiert Corner - irregular stream of stuff: jpluimers

I remember doing this in DOS ages ago (in the Turbo Pascal 5 era) for exactly the same reason: flash the keyboard LEDs to indicate some event was happening, but I’ve yet to find back the source code.

Here is how to do it in Windows using either C# or C: Faking num lock, caps lock and scroll lock leds – About My Code.

–jeroen

via: c# – Way to turn on keyboard’s caps-lock light without actually turning on caps-lock? – Stack Overflow.