Odometer/Trip Question, How is data stored/transferred? Options

[Espo]

I've been thinking about modifying the odometer and trip in my dash for a while now, and I think I have a solution in hand that I'm not quite going to reveal yet, because I have a couple questions I need answered first.

Firstly, how does the car store the odometer information? Is it in the ECU or is it a chip on the dash cluster or what?

Secondly, how is that information transferred from storage to the actual odometer or trip? Is it mechanical or electrical?

The second question is more important than the first - honestly though I have no idea how the thing works, I just know it rolls over every mile I drive (or tenth of a mile) and looks dated, and I want it out of my dash. lol

Thanks in advance for any help.

[aspen]

They are both 100% mechanical. The ECU doesn't set the numbers or anything, otherwise it'd just be a digital display.