Thanks for your reply. The D600 has an Intel 855PM chipset. I gather from your cnczone post:http://www.cnczone.com/forums/showthread.php?t=53254
that you were able to get your C610, which is supposed to be similar to the D600, to work. From what I gather, yours has the 830M chipset, so maybe that makes the difference. I gather the graph has to be almost absolutely flat (is that true?), so perhaps I am out of luck here.
Maybe I should try a SmoothStepper, and not have to worry about what machine I'm running on. It seems crazy that we are still dependent on parallel ports in 2010! I've seen so many posts describing problems with SmoothStepper, however, that perhaps it would be safer just to give up on my laptop. Do you think SmoothStepper is a safe solution? I'll be driving a G540, which is set up for a PP interface.
Thanks again - R