I will try to answer your questions.
You will need to purchase a program such as recommended by Gerry (Mach3) in order to do photos, etc.
Usually the programs have several menus which allow you to input data for your leadscrew, any microstepping, steps per revolution of your motors. All programs (I have seen) will calculate this distance and enter the value per step of the system. In most cases this value can be entered manually also.
This program sends out direction and step information that it has received from a g-code program thru the computer printer (Parallel) point to a breakout board. The outputs of the breakout board go to the various inputs on the drives (Gecko, OMC, Centent, etc). The drives take the step and direction signals and move the various Axis to the correct coordinates to recreate in the material the image or part that was created in a CAD or graphics package that is compatable with the control program.
Hope this explains a couple of your questions.
Jerry |