Yes indeed, depending upon the documentation it is referred to as either the
60Hz or the 60.15Hz
timer. Certainly that's enough information for anyone familiar with Mac
internals to understand
exactly what you are referring to. There are also plenty of examples of this
elsewhere e.g. for
graphics cards the high level claim will be that it supports over 16 million
colours whereas the
engineers know specifically that the exact number is 16777216.
I'll write up a suitable comment with a #define and send through a v2, perhaps
altering the comment
on the timer itself to read 60.15Hz as that's what the reference cited by
Laurent also uses.
If you want more details, this is also in "Apple Guide to the Macintosh Family
Hardware", 2nd
edition, Chapter 12, "Displays", p. 401 (p.440 of the following PDF):
https://archive.org/details/apple-guide-macintosh-family-hardware