F0       F0 = modem does not echo data characters.  This is the
          norm.
          F1 = modem echoes data characters.  If you selected
          this option you could find yourself in the ludicrous
          position of getting three llleeettteeerrrsss for every
          one you type.  Telix might local echo.  Your modem
          could F1 echo.  The other computer could remote echo.