OK ... I reconfigured the system a few times today.  First I tried Chip's suggestion regarding the "reversed" A axis.  I changed the wiring, changed the software configuration, still the same problem.

Then I disabled the smooth stepper and wired direct to the LPT port.  SUCCESS!  I have homing on the slave axis.

I know that this has been discussed on Warp9's forums - and it was suposed to be fixed with the latest release of their driver, but apparently it has not been fixed - or this is a new problem.

I guess I will play in the "LPT World" until it gets resolved.

A reply from "cagray" (Allen) on the Warp9 forum ...

Slave homing doesn't work so well at the moment. Greg is aware of the issue and is working on a fix.

If X tags first it works fine. What I have done as a work around is write a homing routine that first de-slaves, make a small positive A movement then re-slave. This slightly racks the gantry but not enough to put it in to a bind.

I will try this out and see if it works for me.

Chip,

Allen & Greg helped me with this homing routine for the SmoothStepper board.  I just installed it and it works great!

DoOemButton(1024)   'Home Z
While IsMoving
Sleep(25)
Wend

DoOemButton(1023)   'Home Y
While IsMoving
Sleep(25)
Wend

DoOemButton(357)    'deslave axis

Code "G91"          'Put Mach into incremental mode

Code "G0A0.5"       'Move A axis 1/2"
While IsMoving
Sleep(25)
Wend

Code "G90"          'Return Mach to Absolute Mode'

DoOemButton(358)    'slave axis

DoOemButton(1022)   'Home X with A trailing
While IsMoving
Sleep(25)
Wend

DoOemButton(1007)   'Zero All just to be sure

Again, thanks to everyone that helped me figure this out!

Hi, Joepardy

Glad to see Greg & Allen helped you work through the SmoothStepper issue.

It's always great to see everyone working to help resolve these issues by sharing there individual experiences.

Mach's continues to amaze me in it's ability to be adapted to so many system uses and continues to evolve to include so many new products.

Thanks for the update, Chip

Thanks for the reply Chip.  I saw this solution posted ... tried it ... respond exactly the same.  Sorry, that solution did not work for me.

I'm having the same problem with the A being dropped etc but i have a bigger problem in that I don't understand the answer! I have no programming skills at all, so I have neither the understanding nor application skills. Is there some other way to achieve a fix, or what skills would I need to get to be able to achieve a fix? Can anyone assist, please?

Please ignore the last. I read the whole blog. It did worh, thanks