Just one computer and one PP at time.
I would use the card as that has the higher voltage and as such would swing the full high to low required .
You need to have two things in place...
A working xp computer system and then a PP both of which are functional. I will assume that the pp card is like new / known to be good, then that leaves the computer which only you can assert. Without that, its kind of fruitless to go further. All the Mach configuration / drive hookup etc can be worked out if the first two things are in place.
Three assus pc's and they don't work.......good grief. Is this with the same pp card?
The only thing that i had a hard time with was when i just got the new pc, the pp card was installed, but for whatever reason, i had to go in and out of MAch about 10 times before it recognized the pp address. Thus no axis movement. I wrote it off as a fluke.
RICH