Well, back to working on my fencing box I found out that my comparaters (339's)
are open collector.  I was informed that my current setup wouldn't work.

              +12V                      +5V
                |                        |
           ------------           --------------         --------
    Input--|+         |           |            |         |
           | LM339 Out|-----------| Hex Buffer |---------| PIC Port
     VRef--|-         |           |            |         |

However, I happen to be coming in on port B (hopefully) dumb luck, so
will the following work?


              +12V                      +5V
                |                        |
           ------------           --------
    Input--|+         |           |
           | LM339 Out|-----------| PIC Port B
     VRef--|-         |           |

I assume I need to enable the pull-ups on port B.

Roger

Not progressing very swiftly, but learning lots and enjoying myself.
The transition from tech to designing things is interesting.