I have been using the following lines in Fedora Core 1 without problems: /bin/setserial /dev/ttyS4 port 0x280 irq 5 uart 16550 /bin/setserial /dev/ttyS5 port 0x288 irq 5 uart 16550 In Fedora Core 2 both of these give me the following error message: Cannot set serial info: Invalid argument I have checked the archives, bugzilla, and google, without finding an answer to why it will not work in FC2 when it worked in FC1. Anyone with knowledge in setserial that can give me clue on what is wrong? The card is an old ISA-card for RS-422/485 communication (Moxa-card with two serial ports.) /Lars