Date: Thu, 12 Jan 95 17:08:31 MST From: terry@cs.weber.edu (Terry Lambert) To: ache@astral.msk.su (Andrew A. Chernov, Black Mage) Cc: peter@bonkers.taronga.com, wpaul@skynet.ctr.columbia.edu, freebsd-hackers@FreeBSD.org Subject: Re: Small syscons change Message-ID: <9501130008.AA07296@cs.weber.edu> In-Reply-To: <FTKNR5lqb2@astral.msk.su> from "Andrew A. Chernov, Black Mage" at Jan 13, 95 02:05:56 am
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> In message <199501122114.PAA09829@bonkers.taronga.com> Peter da Silva > writes: > > >DEC's cute but bizzarre line wrap behaviour strikes again. > > >You wouldn't believe what I had to do to get it to work right when emulating > >the VT100 on other terminals... > > VT100 have very different behaviour then simple line wrap: > cursor stuck in last position until next char will be printed. > Standard linewarp goes to first column immediately after > printing char in last column. > You mast have an option (ioctl?) in syscons to emulate VT100 line wrap. The actual term is "delayed wrap" and the actual description is "wrap *before* 81st (133rd) character", as opposed to "wrap after 80th (132nd) character". The termcap description of their attribute to deal with this (AM) is *wrong*. This is what xterm means with it's 'Enable Curses emulation". The problem in a partial fix is that "eat CR after wrap" still causes a forced scroll if it was the 80th (132nd) character of the last line. SCO curses handles this on their console (which is *not* "delayed wrap") by outputing the 80th character in the 79th column, and reinserting the previous 79th character. Note that this implies the screen redraw code is very seperate from the actual emulation (screen content manipulation) code. Gee, it's been years since I've written a VT100... I guess it's like riding a bicycle. 8-). Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.
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