Question on weird output from parallel breakout board pin #16?

I am using an Axxus parallel port breakout board with MACH2 on my CNC
Bridgeport. I have just wired up a variable frequency drive. I am
controlling the speed of the drive with a Homman designs Digispeed
with a PWM signal from MACH2.

I selected pin #16 on the breakout board and I seem to be getting a
voltage on it, but no pulse. I changed it in the software config to
be a step signal and got the same. I then looked at the board's
documentation and it says the following:

"Pins 1 and 16 are 5V outputs and can be used to connect with TTL
devices such as transistors, logic gates, or microprocessors."

The Digispeed is supposed to work with an ACTIVE LOW pulse.

I can always rewire a bunch of stuff and steal one of the pins
normally used for a step signal, but I would have thougght that this
would have worked.

This is where I'm getting a little hazy. I always thought that step,
PWM and other signals WERE 5V, so this should be OK. Am I confused?


Thanks,
Jeff