You could do it that way, but in Mach3 people like to home each X-axis motor separately to square the gantry, which clearly can't be done with them both connected to the same output. I'm not keen on that method as it bends the gantry, albeit only slightly, every time you home the axis.

Quote Originally Posted by Wobblycogs View Post
Am I right in thinking that the step line indicates that the stepper should take a step by going high and then the direction line is high or low depending on the direction of rotation?
Yes, that's correct although it can be inverted.