Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site l5.uucp
Path: utzoo!linus!decvax!decwrl!sun!l5!gnu
From: gnu@l5.uucp (John Gilmore)
Newsgroups: net.info-terms
Subject: Please make your programs ignore the "am" capability
Message-ID: <186@l5.uucp>
Date: Tue, 8-Oct-85 06:55:34 EDT
Article-I.D.: l5.186
Posted: Tue Oct  8 06:55:34 1985
Date-Received: Thu, 10-Oct-85 06:07:24 EDT
References: <70@druhi.UUCP> <227@epicen.UUCP> <2857@sun.uucp>
Organization: Ell-Five [Consultants], San Francisco
Lines: 21
Summary: Ignore "am" and just reposition the cursor afterward

In my experience the "am" capability in termcap causes more hassles and
screen glitches than it saves.  Often (as on the VT100), whether or not
the automatic wrap is enabled is set by a dipswitch -- which is NOT
accessible to the computer -- so it requires TWO termcap entries and
requires the user to pick which one (or diddle their dipswitches to
match the termcap entry).  And with other terminals, many people who
create termcap entries don't notice whether am should be off or on -- if
indeed their terminal manual tells them.

All this could be avoided if programmers would simply avoid assuming anything
about the cursor position after writing in column 80.  Avoiding that
assumption means having to send a set-cursor-position after you write
to column 80.  In many cases you would have done that anyway; in the rest,
the three or six bytes are worth it in lack of hassle to the user (no
bad termcap entries or screen garbage).

I fixed "vnews" to ignore "am".  Please do it to YOUR software.

(Note that writing in column 80 of the last line is hazardous.  I like
the trick of writing the char in column 79 and sliding it over with insert-
character, but that takes work.  It's easier to just avoid painting it.)