how to communicate using the parallel port

You can communicate the parallel port using Windows library Inpout32.dll. For code samples, see, for example, these CodeProject articles:

Control Electrical Appliances using PC[^],
Hardware Interface Programming in VC++ - Part I (Port Access)[^],
17 Channel Logic Analyzer[^],
Parallel Port Pin Control Library (PaPiC)[^],
Port Access[^],
Stepper Motor Control through Parallel Port[^].

—SA