Can we turn on/off Scroll Lock light by software instructions?

Is it possible to turn on/off Scroll Lock light by software instructions like outb or some开发者_如何学Gothing else? And if the answer is yes, can we restrict the use of these instructions so that they are only allowed in ring-0?

question part one (is it possible?): ledd

ledd is part of the ledcontrol package, which allows you to show arbitrary information on the normally-unused keyboard LEDs. It is fully scriptable, so you can show any TRUE/FALSE condition accessible or indicate an arbitrary value. It supports blinking LEDs with priority levels and animations. The LEDs not used by ledd should function as normal.

Take a look at the SetKeyboardState Win32 API function