Chicony KB-5161 555 Timer Question!?

[Polecat]

In the Chicony KB-5161 wiki...

wiki/Chicony_KB-5161

...one of the illustrations shows a 555 timer chip and associated components. Any idea what this was used for?

Reason I ask is that my Lite-On SK-0002-1U...

keyboards-f2/northgate-alps-t17761.html

...has legends on the PC board for a similar circuit (labelled 555, but the more common 8 pin version) in the upper right corner, but those parts were not installed on my board. I haven't traced out the connections to see what it might have done, but I can do so if nobody knows why it was there. The 555 is commonly called a "timer" but can also be used as an oscillator or pulse generator.