09-26-2019, 11:20 AM
I am using a JU-475-4 drive. I have not looked at the -3 model. It may not have a DX jumper. 'EX' is the jumper that allows the reading/writing without the index mark. The DX jumper is a speed jumper (which is ignored) so it is just convenient to remove that jumper and place it on the EX position.