[nos-bbs] here's a url

[ve1jot]

This message explains how he set up xastir in linux to a dual-port tnc 
in kiss mode, I've set
my system up in a similar way, but with more "pty's" so that jnos, 
xastir, and fbb 7.04r, can
all share any of the 3 kams 6 ports...the main gotcha that I found in 
ubuntu 9.10 is they've
done away with /dev/pty0 /dev/pty1 etc! There is now /dev/ptmx only 
until using that device
creates /dev/ptmx0  automatically in sequence upwards. I had to use a 
boot-time option to
force the kernel to make /dev/pty0 thru /dev/pty9, and there's a compile 
time option if you
compile your own kernel to turn it on.

http://www.mail-archive.com/xastir@lists.xastir.org/msg01180.html