Let's test that the inputs into the parallel port are being read correctly by Mach3.

Use a jumper to short from pin 25 (GND) to pin 10 - on the PC's parallel port...

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On the diagnostic page...

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Move to 25->11

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25->12:-

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25->13:-

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25->15 (NOTE: skip 14 - that's an output!, not input):-

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Confirm that behaviour then we're confident that the parallel port inputs are able to be monitored by Mach3.