Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!mcsun!sunic!tut!santra!hemuli.atk.vtt.fi!tml
From: tml@hemuli.atk.vtt.fi (Tor Lillqvist)
Newsgroups: comp.windows.x
Subject: Re: Xterm , 8 bit international fonts and font editor
Keywords: xterm , font
Message-ID: <4134@hemuli.atk.vtt.fi>
Date: 19 Oct 89 10:09:56 GMT
References: <927@digiw.UUCP> <965@maxim.erbe.se>
Reply-To: tml@hemuli.atk.vtt.fi (Tor Lillqvist)
Organization: Technical Research Centre of Finland
Lines: 36

Another problem if you try to extend xterm to 8-bit character sets is
that it uses isprint in charproc.c:
	...
		switch(pstate) {
		 case CASE_PRINT:
			/* printable characters */
			top = bcnt > TEXT_BUF_SIZE ? TEXT_BUF_SIZE : bcnt;
			cp = bptr;
			*--bptr = c;
			while(top > 0 && isprint(*cp)) {
				top--;
				bcnt--;
				cp++;
			}
	...

I don't know what this code exactly does, but clearly xterm shouldn't
use isprint, as the printability of a char depends on the font in use.
It needs a way to know what character set the current font represents,
so that it can decide if a certain character is printable or not.  And
this of course affects the tables in VTPrsTbl.c, too.  Oh, this really
is a mess.  What if you would like to use xterm with a IBM PC font,
where *all* characters are printable, for instance when telnetting to
an AT running VP/ix or some other DOS-on-UNIX emulator.  Or what if
you need the HP Roman8 character set, or DEC's eight-bit character set
(does DEC have their own?).

In article <965@maxim.erbe.se> prc@erbe.se (Robert Claeson) writes:
>The *real* way to support true Latin 1 would be to write a VT3xx-
>emulator (don't bother trying to extend xterm anymore). VT3xx terminals
>uses, among others, ISO 8859/1.

This sounds like a good idea. (But don't ask me to do it...)  But is
it necessary to emulate a real terminal at all?
-- 
Tor Lillqvist, VTT/ATK