Parallel Port Viever shows you how parallel port works on hardware level. You can see when it is 5 Volts on it's pins. You need download some files from my site in order to run this program!!! In order to use this program on Windows NT/2000/XP you need to install the driver for parallel port. There are three steps of installation. 1. Download UserPort.sys and put it to \WINDOWS\system32\drivers\ 2. Download parport.dll and put it to \WINDOWS\system32\ 3. Download UserPort.exe and run it. Configure as showed in the picture below, then press Update afterward press Start.