I think we are starting to get there. You mentioned "AutoZero simply tells Mach to set Zero (or Home Off value) to the machine Coords DROs when you reference the machine."
I think that you are absolutely right. My problem is when my Mach3 starts up the Machine Coord is set to X = -0.0005 even before I press the Reset button. I cannot phantom why it is doing that, but it is. This is why when I RefAll, the axis moves. Mach3 is starting up with a Machine Coord not zero and is zeroing to the machine coord dro, which is taking the table off the zero I want.
When I press the ResAll, it's from the screen, not the Pendant (which is an excellent pendant, btw. Highly recommended).
Here is the contents of Macropump.m1s
If GetUserLED (1010) Then
If Not IsActive (Input2) Then
DoOEMButton (1003)
Message “Program Stopped Spindle Fault”
End If
End If
As far as the parallel port, I am using a Derek Hillbilly bob board which works very well. Surprisingly well. I don't think this is the source of the problem given that Mach3 starts up with the machine coords as noted above, even before I press Reset. If there is some way to make Mach3 start with machine coords set to zero, then my problems go away.
Still cannot imagine why it is so difficult to move the bed to any location I wish and press a button to force Current Position, Machine coord, and work offset to zero at that location.
I really appreciate your help.