[Xastir] Serial tnc and Prolific USB adaptor

[David]

Hi All....just upgraded my Linux Ubuntu box and it dosent have any 
serial ports
have a Prolific Serial to USB adaptor but cant work out how to get it to 
work with the
Serial TNC config....
the adaptor is on /dev/ttyUSB0 but cant find out what ttyS port it is 
using to
put the details into the config

I know this will be an old problem but cant seem to find an answer in 
the archives

Thanks for your help
David VK4BDJ in sunny North Queensland