To do circular interpolation on my Cincinnatti I would put in say G0 X3.0 Y0.0 Z0.0 then G0 X3.0 Y0.0 Z-1.0 I0.0 J0.0 K.1 F25.0 and I would bore a hole 6" in dia. and 1" deep. That does not work with a Yasnac/Tree and the book is real close to being worthless. Also on my Cincinnatti if I put in a tool length and tell it M6 T1 then G0 Z0.0 it will go there, pretty simple. I have tried every thing I can think of after a tool length measurement and doing a Z 0.0 just makes the head go up to the machine 0 Its enough to drive me to drink and its begining to look like a short drive. Maybe there is a clearer book