Thanks for the link, discovered a whole new world of documents under the html link on the docs page, assumed it was just online browsable versions of the pdf docs.
LinuxCNC does the work, PathPilot is the UI.
A quick look at PathPilot last night makes me think most of what's required for my manual tool change is already there. Their manual tool change depends on collection of tools, each mounted in a TTS (Tormach Tooling System) collet, all pre-measured and in the tool table. PathPilot can do the tool measuring prior to starting a job but not once the job is underway. At least I think that's how it works.
This doesn't work for me with a morse taper collet chuck, changing tools and collets as the job progresses (currently each tool in its own ngc file).
I need to do a bit more research in to what the buttons and and associated files do but it doesn't look too difficult ...
(Attached is the ETS setup page)
Ken.