virtual serial

 socat -d -d pty,raw,echo=0 pty,raw,echo=0

prints the name of the devices, then, for instance,

minicom -D /dev/pts/14 -H -w

and 

 sudo screen /dev/pts/13 115200 vt52

or sniffing by

sudo cat /dev/ttyUSB0 | tee /dev/pts/4 | xxd -c 1

sudo cat /dev/pts/4 | tee /dev/ttyUSB0 | xxd -c 1

sudo getty /pts/8 9600 vt52

to edit the screen size

stty rows 24 cols 40