Brian - I dont know - but yes - I was looking at the same display yesterday, thinking the same thing.
If you have a set of manual switches that you can access - e.g. your limits and your homing - then I would set them up as 10,11,12 and 13. If you then press them manually, in order, you should see them light, which will give you an idea where they are. All the diagrams of the LPT1 inputs/outputs I have show 13 pins top row, and 12 pins bottom row and pin 1 is top right, pin 14 is bottom right - if that is any help.
I cant do that myself, unfortunately, all my inputs are electronic and relying on the table moving too and fro.