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

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