How to play with a SNA Terminal Control Unit.
 
For ALMVMY, there's a SNA control unit at 6E0.  To start it on PVM,
 
ATT 6E0 PVM
SMSG PVM DEFINE nodename NEW TYPE S3270 LINE 6E0
SMSG PVM START nodename
 
 
To query it,
 
SMSG PVM QUERY LINE nodename PORT nnn    (I think)