Hi Tony,
I'm trying to do the same thing with my paradigm. I tried the above suggestions but for some reason it didn't work for me.
Here's a section of mine. Do you have any suggestions?
********************************************************************************
MARKERS
********************************************************************************
<port pressmarker>
/ port = lpt1
/ subport = data
/ items = ("00001001")
/ erase = true ("00000000")
</port>
********************************************************************************
TRIALS
********************************************************************************
<trial green1>
/ trialduration = 1500
/ stimulustimes = [0= green; 0= greenmarker]
/ validresponse = (" ",noresponse,"p")
/ correctresponse = (" ")
/ responsemessage = (" ", pressmarker, 100)
/ responsetrial = (" ",correctfeedback1)
/ responsetrial = (noresponse,incorrectfeedback1)
/ responsetrial = ("p",pausetrial)
</trial>