That is because you probably have bit 4 of Parameter 36 set in your mill software. I do not have time to go looking to see whether any of the reports you posted were from the mill installation. Maybe you can just tell us what you have in P36 on your mill installation.Then why does it change mine and many others to proper spindle output in cnc12 mill with a ratio of -.117 entered into parm 65 or aka wizard entry spindle low gear ratio and has for 3 years with my encoder mounted on top of the spindle. ... And i have a comercial grade hand held laser tachometer that says i am reading actual spindle rpm, bothe in high and low range from cnc12 mill,just not cnc12 lathe.
What Tom wrote notwithstanding, CNC12 mill does support RPM display and rigid tapping based on a spindle encoder that is on the motor side of a gearbox. That comes with the caveat that you cannot use peck tapping, or re-tap a hole, in any range that does not provide a 1:1 ratio between the encoder and the spindle. That limitation is because the index pulse will not be synchronized.
You tell CNC12 Mill that the encoder is on the motor side, and therefore affected by gear range ratios, by setting bit 4 of Parameter 36 (i.e. by adding 16 to the value).
As far as I can tell, CNC12 Lathe does not support that feature. Probably because lathes are almost always expected to perform threading in multiple passes, and that cannot be made to work with an encoder that is not 1:1, again because of the lack of index pulse synchronization.