[Tinmuk]

I went out and took a look at the wiring to see what I needed to do to trace everything, and I found hand written on the inside of the cabinet behind the terminal block was the following.

black-forward
red-reverse
red/black-M9
white/black-M8
orange-M12

So I looked for those color wires at the relay strip and traced them to the 25 pin DB connetor at I/O 2 and here is the pinout

3- black
4-red
5-red/black
6-white/black
7-orange

Now I noticed that pin 1 & 2 are jumped together at the connector to a heavy white wire which appears to go to a transformer in the original Hardinge power box. There is also a heavy blue wire that is jumped from pin 19 to pin 20 and appears to go to a connector marked L on the Sabina VFD.

I also checked the fwd and rev on the Sabina and red is indeed reverse and black is forward, just like the handwritten note indicated.

I hope all that makes sense to you. If needed I can check everything more carefully, but as you said there are not a lot of M-function on this machine. spindle, coolant, threading and collet are it.