Thank you for the offer Rob, I think I'll take you up on it. Sorry it took so long to reply, been a crazy day here today.
I've attached a snapshot of my screen set. I believe it is just the standard mach3 mill screen set as I haven't changed anything.
As far as where I'd like the button, I think it would go nicely in the box that now has the spindle speed. Our machine does not have a spindle at all so that information is unnecessary anyway.
A button for Laser Fire there would be great, and maybe a light indicating that the laser is currently firing (if possible).
The m function I have written is labeled as m1000 in the mach directory. I think I'd still like the spacebar to be the keyboard hotkey though. I have wired an external pause button already (although I probably wouldn't have had I read the hotkey list before).
Thanks again!