Common Printer port settings are as follows:
LPT Port I/O Address LPT1 378 LPT2 278 LPT3 3BC
Compaq Servers have the following Parallel Port Setup:
LPT Port I/O Address LPT1 3BC LPT2 378 LPT3 278
So whenever setting up printer ports, be sure to either make the operating system use the address that the Compaq printer port is using, or change the Compaq hardware to use a different printer port (to change the addres to match your software).
Common communication port settings:
COM Port I/O Address IRQ COM1 3F8 4 COM2 2F8 3 COM3 3E8 4 COM4 2E8 3