Millisecond Forums

Within a parametric n-back task, I'm trying to send a response marker out to the parallel port for correct responses (hitting the 'a' key at a target response). Currently I am getting stimulus markers specific to
each level of n-back (1,2 or 3) and I've copied the part of my script specific to the parallel port below. Not sure how I should proceed to have a response marker coming out as well. 

<port EEGsignal>
/ port = lpt3
/ subport = data
/ items = ("00000001", "00000011", "00000101")
/ select = values.N
</port>

<port EEGsignal2>
/ port = lpt3
/ subport = data
/ items = ("00000010", "00000100", "00000110")
/select = values.N
</port>

<port EEGsignaloff>
/ port = lpt3
/ subport = data
/ items = ("00000000")
</port>

<block EndExp>
/ trials = [1 = EndExp_trial]
</block>