This might be a little off topic, but where it the outb function? Is it built into GCC? I don't see a definition in the kernel source, nothing in 'info gcc' and 'man outb' says to look in 'man 9 outb' which I don't seem to have. and can't find on the net. I know its just a wrapper function for the assembly outb, but where does the C outb() come from? Tom -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ IRC Channel: irc.openprojects.net / #kernelnewbies Web Page: http://www.kernelnewbies.org/