One-way direction in Z

[pgh3]

Port 1 is set to $H378 and Port 2 is left unchecked. Is this what you mean?

[Hood]

No I am meaning you have Port 2 entered for the Z axis Dir pin, see screenshot of your xml.
Hood

[pgh3]

Yes, that was a trial to see the effects - and this means you have the wrong version of xml - sorry about that.
I have since closed Mach3 and reloaded it - all axes still work correctly - and I've included the current xml.

[Hood]

If its working now then is it not likely that that was your problem previously? Will look at your xml but really not much I will see if its working.
Hood

[pgh3]

Yes, my thinking also - I'm puzzled because the only thing different between not working and working was a setting for Z of 8 & 9 and then back to 6 & 7, as per Angel Tech's suggestion.
And I'm afraid this is always going to be a possibility in this open-ended control system - that's why servos are so much better and expensive.
Again, thanks for your input and time. And yours, Angel Tech.

[pgh3]

I think I know what caused the problem before:  I had selected ECP as a print mode in BIOS - it should have been EPP!
My computer has the option to select both and I have - the Z axis has been both directions ever since.
I thought I need to share this information here so that anyone else with a similar problem may get a clue...
Thanks to all for your help.

[Hood]

Good to hear, thanks.
Hood