Need help configuring marlin for A4988 drivers

Greetings, I downloaded the ready made firmware, but I can’t seem to find what values need to be changed (cut in half) for 16 steps for A4988 drivers vs the original 32 step drivers you guys are all using. I tried searching but couldn’t find it. Is it under


Thank you for the quick reply. I see it now. Cutting everything in half left me with this: #define DEFAULT_AXIS_STEPS_PER_UNIT { 100, 100, 400, 100 } //MPCNC

Depending on your hardware that should be correct.

I am french and I did the same thing because I think I have the same configuration
arduino mega ramps 1.4 a4988 but nothing changes ??
I can put 1 or 10000 the engines turn the same angle.
I do not have the resistor!
to confirm my uploads on marlin MPCNC813 GLCD T8 I change the name of the machine and I see that it works on the screen.
Thank you
I will show you pictures of my beast.