Try port 300 these 3com's have plug and play enabled by default and that has worked for me. if all else fails get yourself a dos boot disk (if you are running a platform that supports dos) and the dos drivers and utilities from 3com and run the 3c5x9cfg.exe utility and set it for the port and irq you want. you could also try from dosemu but you have to make sure linux isn't trying to use it or 3c5x9cfg will give you trouble.