Are other devices running on your computer?
The HP LaserJet 3300 series product may not share a parallel port. If you have an external
hard drive or network switchbox connected to the same port as the HP LaserJet 3300, the
other device might be interfering. To connect and use the HP LaserJet 3300, you must
disconnect the other device or you must use two ports on the computer.
You might need to add another interface card. Hewlett-Packard strongly recommends an ECP
parallel interface card.