A MaxNc Retrofit on my Dyna-Myte 2000 CNC mill

I am retrofitting a dead Dyna-Myte 23000 CNC tabletop mill with a
MaxNc controller board and software kit that I purchased for about
$250.00 a few years ago. My problem is the limit/home switch wiring. I
simply can't make heads or tails out of the single paragraph of
instructions about how to hook them up. What I have is two loops,
consisting of the 3 positive limit switches and the 3 negative limit
switches, set up so that if any switch is tripped, it opens the
circuit. I am hoping to use the same positive limit switches as the
Home switches by putting a switch in the line and directing the output
to either the "Home" pin or the "limit" pin, as it appears that it
won't work to simply connect the switches to both at the same time.
What mystifies me is where do I connect the "other" end of the loop?
Ground? Someone suggested I had to supply a low level (<50ma) 5 volt
source. Does this make sense? I have listed the location of pictures
of the circuit board, the circuit schematic and the very short
paragraph describing the hookup. If anyone can offer any insight on
this problem I could complete my project. BTW, I know the MaxNc board
is a cheap, cheesy substitute for a real controller, but I'd like to
complete this project before I start trying to improve on it. Thanks
for any help
Fred Howe
pictures are at:
www.professorwiz.com/fred/circuit1bd.jpg
www.professorwiz.com/fred/circuit1dwg.jpg
www.professorwiz.com/fred/description.jpg
or e-mail me and I will e-mail them to you.