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From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.unix.questions
Subject: Re: Alternate characters at bottem right hand corner.
Keywords: curses, ansi, vt100
Message-ID: <13289@smoke.BRL.MIL>
Date: 3 Jul 90 21:38:48 GMT
References: <1344@wiggles.UUCP> <13250@smoke.BRL.MIL> <808@ehviea.ine.philips.nl>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 17

In article <808@ehviea.ine.philips.nl> leo@ehviea.UUCP (Leo de Wit) writes:
>Unfortunately, the vt100 (one of the terminals this was asked for)
>doesn't support character insertion.

The VT100 does support line insertion (via manipulation of the scrolling
region), and thus the technique I described can be used.  You must of
course build the entire  desired last line somewhere other than on the
last line of a scrolling region that includes the bottom display line,
then scroll in reverse to move the desired last line to the bottom of
the display, then fill in the vacated top line or lines of the scrolling
region.  This is a lot of work simply to use one cell location, and most
applications don't bother to use that location (a much simpler solution).
If I recall correctly, a genuine VT100 doesn't scroll at the end of a
line until the next character is received and is found to be other than a
carriage-return, but the exact VT100 behavior is very quirky (there are
several bugs in the microcode) and impossible to correctly describe using
termcap/terminfo.  In particular, "am" is never correct for a VT100.