[nateman_doo]

I have a functioning Arduino uno board and the corresponding motor control stacked on top of it. I would like to have a spare board. How do I copy the settings of one set of boards, onto the other?

I am using it to drive a nema 17 motor.

[hfjbuis]

You can read the settings by sending a $$ command to the controller. If you capture the output in a text file, you can then send this text file to the new controller the same way you do when sending a gCode file.

You can use the Arduino terminal window to do this. Most gCode senders can also do this by logging the output. Some even have a utility to backup and restore settings.

[cyclestart]

If it's grbl settings you need hfjbuis has provided the answer.
If it's some non-grbl sketch hopefully a copy was stored somewhere. Otherwise...... trouble.