I am using this card in a 560, it works flawlessly, both as modem and eternet. As I am getting late on this thread: 1. Which card is it, the US or the International? 2. Which os? Get the newest drivers from Xircom. 3. if under DOS/Win3.x, I think you have to set the cards I/O etc with the driver options in the autoexec and config files.