The strange thing about your experience is losing position on an axis which has not been used. This sounds like a problem in wiring (internal one in the PP card? Not likely, I think, being on 2 computers) such that each time there is a direction signal in one of the axes (probably X since your direction changes where in X?) it somehow finds its way to the step line. May be your outputs were not pulled down (or up) and the Smooth Stepper takes care of this.
Selecting which DRO you'd like to see is fine I think. Don't know though why would someone want the old type DRO - it's either you use the tool table in Mach or not, and if you do you then you have an offset for each tool.
The way I do tapping is by using the spindle as a rotary axis (the SwapAxis command in swaps outputs of spindle and 'A' axis) and then program like this:
G1 Z-10 A10
This will rotate the spindle 10 revolutions and advance the tap 10mm into the workpiece. So this will tap 1mm pitch thread to a depth of 10mm - M6x1 for instance. Then a reverse move to pull the tap out.
An option for a wizard would be entering the pitch and depth and it would calculate the number of turns of the spindle and output the Gcode.
As I said, this screen set is really cool and very useful.
If I may suggest something, I'd love to see the new Tool DRO, Brian implemented for Turn, being added to it. This OEM DRO 246 and it shows current tool and current offset in the format xxyy. Adding a 'T' in the formatting string makes it look even better: Txxyy.
Also, as I have a servo motor on my spindle and do (kind of) rigid tapping and indexing I would like to see a rotary axis DRO as suggested above by Rich.
That's COOL, Wes! Very good looking too and I think you succeeded with the "professional look". I know I will be interested in it. When do you think it will be finished? I have another lathe I am converting to Mach3 and I plan to use it for one off''s and was looking for something like this.
Congratulations on your first machine rebuilt. Looks like you did well. This is a very good machine to own. I have an Emco C5, which I like, and have been looking at acquiring one of these larger versions with automatic chucks.