Hi Ralph -
Thanks for your advice. You are probably running a different M3 version than I am - just to be sure something didn't get inadvertently changed, I have re-downloaded the current version of Mach3 from the New Fangled website ( Version R3.043.066 ), installed it, and the screen comes up exactly like the one in my picture above. I did try the Operator -> Edit Script function, but that button is not editable. I did download the "OEM List Alpha 6.1" (Excel file) which appears to be a really comprehensive list of all the machine calls - its something I'm going to have to study and try and understand how to read/use it. In the meantime, I'll just have to use my controller as is which is certainly not the end of the world.
Again, thanks for your help!
Vic