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From: gwyn@brl-tgr.ARPA (Doug Gwyn )
Newsgroups: net.info-terms
Subject: Re: vt100
Message-ID: <5339@brl-tgr.ARPA>
Date: Tue, 16-Oct-84 19:23:28 EDT
Article-I.D.: brl-tgr.5339
Posted: Tue Oct 16 19:23:28 1984
Date-Received: Sun, 21-Oct-84 10:13:53 EDT
References: <459@uwvax.UUCP> <5084@brl-tgr.ARPA> <194@bragvax.UUCP> <297@ptsfa.UUCP>
Organization: Ballistic Research Lab
Lines: 25

>	... The only difference
> (problem) I've found so far is that Crosstalk does not have/support
> the xn/xenl glitch in column 80. It does wrap to the next line.
> This is easy enough to turn off, but I've also discovered that
> if you're inserting text into a line which wraps to the next line,
> the second line doesn't get displayed correctly. Entering a ^L does
> fix the display. I've looked at the escape sequences, tried lots of
> padding, and for the life of me don't see the problem.
>
> Another product, SmarTerm 100, also provides reasonable vt102
> emulation WITH xn/xenl. I haven't really tested it against the
> above conditions.

There is a common misconception about the VT100 and the xn/xenl
capability; even the most widely distributed termcaps contain this error.
Auto-margin should be taken to mean that IMMEDIATELY after display of a
character in the last column, the cursor is repositioned to the beginning
of the next line (possibly with scrolling if wrapping from the last line).
Whether or not a VT100 will auto-wrap depends on what is sent to it while
the cursor is positioned "past" the end.  The correct way to describe the
VT100 is NO auto margins and NO newline glitch.  In the absence of the
auto-margin capability, termcap/terminfo-using software will not have any
problem with this VT100 feature.  The wrapping upon character insert is
independent of auto-margin and is supposed to be described by the "in"
capability.