How to use serial ports?

[Tapio Lehtonen <tapio.lehtonen@dnainternet.net>]

I try to connect two pc hosts with serial ports with a null modem cable. 
I assumed starting kermit on both ends, setting line, speed etc. to 
suitable values would allow me to see what I type on the other end. But 
no such luck.

I admit it is 9 years since I last used serial ports for anything, but 
at those far away times I got them working. Is there now something that 
must be set up or turned on to use serial ports?

I use Debian GNU/Linux Squeeze, ckermit. I tried also with gtkterm to 
rule out ckermit as the not working part.

   Tapio Lehtonen