Hi
Look at this link. Here you will find an example which uses the parallel port als DIO Port.
http://zone.ni.com/devzone/conceptd.nsf/webmain/72C6FC6CE4AD4D1386256B1800794596?opendocument
This is an interesting Link too:
http://zone.ni.com/devzone/conceptd.nsf/webmain/72C6FC6CE4AD4D1386256B1800794596?opendocument
Remember that you have to install an accesshw.dll before you can use the IN/Out Port VI's under Windows NT.
Bye
Regards,
Luca