Parallel Port Debugging: in the name of CNCkind

Ok smart guys,

I have a PC based CNC controllers from Backtracks. Unfortunately they no
longer support this model, the CNC SW (DOS based) for it leaves much to be
desired.

So, I am in the process of figuring out how to make these controllers work
with Doug Yeagers CNCPRo software. This means I need to reverse engineer
how my PCs LPT port is communicating with the controller (driver box). It
can drive 4 stepper motors.

My plan is to decode what the existing CNC SW is sending the LPT. When I
have captures the protocol coming from the SW, I should be able to
configure CNCPro to duplicate this protocol.

One method of accomplishing the above would be to breakout the signals and
drive some leds for data, status register and the control register. This is
too much like work. Another would be to use a PC-to-PC Parallel-to-Parallel
port cable and have the second PC log the first PCs LPT activities.

Finally to my question, does anyone have any software that would allow me
to connect two PCs by a parallel port data transfer cable and monitor the
activities of the first?

Assistance is greatly appreciated.

Paul Devey