Ask for explain some functions in Gmoccapy

I already found some tutorials. I'll try it. If I can't do it, I'll ask you to do it.

Succeeded. Did I do it right? Should I do the same for 2.9?

github.com/LinuxCNC/linuxcnc/pull/1803

If it's the same fix then it is better to make the change only to the 2.8 branch as we prefer the "merging upwards" workflow. See also linuxcnc.org/docs/html/code/contributing...the_linuxcnc_project