I think on U/Linux the serial ports are named /dev/tty??? on my Xubuntu
12.04 they are /dev/ttySo on up. The USB ports are /dev/ttyUSB0 etc up
to the number of USB ports when something is plugged in like a sound
card or USB/Serial adapter.
Not sure how you can control them, other than making sure you plug in
the adapter to the same port each time. You can keep track by the
command line by typing in at your prompt "ls -l /dev/tty*" with out
quotes.