Hood,
Ah ha!.....thats a great idea, especially in view of the fact I took the side cases off my desktop computer yesterday & completely chickened out on even trying to tap the logic supply voltage.....waaayyyy to much stuff for this kid!
But I did set a vom to millivolt & lo & behold I got an indication of a pulse train @ the respective ports in time with my key presses.
Today, just for kicks I'll do exactly what you've suggested, just to see what the probe shows.
This particular board (the 4AUPC) is waiting for replacement components & so is the new PRO board...missing mosfet, so I'm @ a standstill....yesterday I did the physical stuff for the (3) homing switches, but other than that, the machines' ready to go....it dosen't look as good or have all the operator interface stuff the first machine I put together (for a customer...there are pics of it w/my name attached posted), but then it dosen't need to....I'll be showing it soon....thanks again for your help.
George P.