NUL transmitted after <CR>

[mercer at npdiss1.StPaul.NCR.COMDanMercer]

Configuration:

                        ------           ------                        
                        | T  |           | T  |                       
                        | o  |           | o  |                       
                        | w  |           | w  |             -------   
    -------             | e  |           | e  |             |  I  |   
    |  P  |             | r  |           | r  |             |  N  |   
    |  C  | Token Ring  |    |  kermit   |    |  Ethernet   |  T  |   
    |     |-------------|    |-----------|    |-------------|  E  |   
    |     |             |    |           |    |             |  L  |   
    -------             ------           ------             -------   

    The PC is using NANSI.SYS for terminal emulation.  The Token Ring
    Tower is at SYSV R2.  The Ethernet Tower and INTEL Unix are at R3.2
    running WIN/TCP. 

Symptom:
      The PC prints an extra space in vi.

Analysis:
      The kermit session was captured on the Token Ring Tower side and
      the log replayed.  The log also caused the problem.  The log was
      examined with a hexadecimal dump utility and it was noticed that
      every carriage return was followed by a NUL.  ANSI.SYS and its
      clones treat NUL's as spaces.  This causes alignment problems
      in vi and other full screen,  character mode appls.

      An ethernet data capture was performed.  Examination of the packets
      showed NUL's following CR's.  Unable to determine if same
      problem exists over normal tty lines.

Bypass:
      In terminfo,  code cr=\E[80D.  This works for vi,  does not
      work for elm.


This problem has also been seen in a Tower 700 running SYSV R3.2
(but not in Tower 650).
-- 

Dan Mercer
Reply-To: mercer at npdiss1.StPaul.NCR.COM (Dan Mercer)