How was 0 drive offset determined when Accuraterip was developed

[Tig]

I have some questions which I've been curious about - When Accuraterip was first being developed, how was it determined/decided what a "0" offset would be? Is there such a thing as an "absolute zero" offset? What technical procedures were involved in figuring this out?

Thanks!

[Spoon]

Re: How was 0 drive offset determined when Accuraterip was developed

We used EACs reference