Non synchronized Num Lock

Starting with firmware version 2, there is a feature called Non-synchronized Num Lock. The idea is that the host OS will think the Num Lock mode is normally off, even if the keyboard is internally in Num Lock mode. But as soon as a key is pressed that generates a numeric keypad keypress, the firmware will send a Num Lock keypress/release first, thereby toggling host OS Num Lock mode on.

At the same time, the firmware sets a cooldown counter to 255 iterations. At each subsequent column scan the counter is decremented, and when it expires, another Num Lock keypress/release is sent to the host, turning the Num Lock mode off.

If the OS-level Num Lock mode is on when a numeric keypad key is pressed, this logic is bypassed.