General Computers COM Ports When configuring modems on a PC-compatible system, I/O and interrupt conflicts are quite common, especially with the mouse. To aid in removing such conflicts, the following are the 'standard' interrupt and I/O addresses for the main four COM ports. Note that to get certain types of modems to work, especially the so-called "plug & play" models, you may have to experiment and use the 'pseudo' COM ports 5-8 by adjusting I/O addresses. Com1, I/O Address - 03F8, Interrupt (IRQ) #4 Com2, I/O Address - 02F8, Interrupt (IRQ) #3 Com3, I/O Address - 03E8, Interrupt (IRQ) #4 Com4, I/O Address - 02E8, Interrupt (IRQ) #3   Add: Del.icio.us | Digg | Furl | My Yahoo!   Discuss This Tip Print This Tip Get E-Mail When New Tips are Online Return to the General Computers page.