Let's get serial debugging going here...
I've been meaning to do this for a few years now, but only recently have I bought a null modem cable, and only today have I tried it out.
I'm running Ubuntu on the receiving machine, and a recent build of Haiku on the other; null modem cable connecting the two (obviously). I start up PuTTY in Ubuntu, specify 115200 as the speed, boot up the Haiku machine but I don't receive anything in PuTTY.
I've confirmed that serial/COM is enabled in the BIOS of both machines. Any ideas?