bci2000.org BBS

I am trying to modify the code using Borland 6 so that I can plot a square wave on one of the channels. I am trying to synchronize it with a stimulus that we are presenting. This way we can see exactly when the stimulus is changing in relation to the signals we are recording. The problem is that i don't know exactly where I need to look within the code. Is there an easy way to do this?

Thanks in advance,

Rebekah