Re: Terminal Emulation

From: Michael Everson (
Date: Fri Oct 30 1998 - 06:22:02 EST

Ar 12:42 -0800 1998-10-29, scríobh Frank da Cruz:

>Again, the rationale is not simply that they would be nice to have (and
>they would be, for many reasons not related to terminal emulation). It
>is that certain terminals already include a selection of single-cell hex
>byte pictures; some terminals have as many as 32 of them.

Um, Frank, why did I make 256 of them then? >:-(

>If we are to include the graphic characters of such terminals in Unicode,
>then we would have to include these hex byte pictures. But then it seems a
>shame to include some byte values but not others. Why not include them all?
>On the other hand, if we conclude that hex byte pictures are not needed at
>all, then we can not fully emulate the terminals that have them.

Surely the ordinary user is not expected to deal with hex-byte representations.

>When putting together this table, it occurred to me that when debugging
>Unicode data streams (e.g. in a Unicode-based line monitor or protocol
>analyzer), it would be good to be able to show the presence of a character
>that is "guaranteed not be a Unicode character at all". There will be a
>strong temptation to use it as an escape, and debuggers will want to show

Users will need to "show invisibles". Whether they need to do that with
special UCS characters designed for that purpose and for no other is the

>I agree. I, personally, can live without the rest and life will go on. But
>before we decide to dismiss the ideas in this proposal, recall the original
>motivation: to stop the proliferation of incompatible encodings for the same
>glyphs. More and more Windows-based terminal emulators are coming on the
>market all the time. Each has has to include its own custom font, encoding
>the same glyphs at different code points.

It would be nice to know what the actual manufacturers want. Are any of
them members of the Unicode Consortium?

>I think we now can agree that
>terminal emulation is not dead and will not die any time soon. Therefore my
>hope is that there can be a standard encoding to follow, and regular
>off-the-shelf fonts can be used -- both for the emulators themselves, and
>for applications that will interoperate with the emulators via copy-paste or
>any other means.

OK, but the UCS will be used for a long long long long time. Probably
longer than terminal emulation.

Michael Everson, Everson Gunn Teoranta **
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