With the 6503 you can use DAQmx and the assistant. I would suggest first of all Going into MAX and setting up your channels in there. See Manual or help. Or you can use the assistant to do this for you. Drop the assistant onto the block diagram and let it come up then select digital I/O. from there you can select port input/output or line input/output. You just need to figure if you want the whole port to become an input or output or if you need to do it individually by line. there are a bunch of examples for this in the help under digital I/O it is not really that hard to do. If you still have trouble after looking at the examples let us know and maybe post your code so that we can see if there is anything else going on.
Joe
