[no subject]

[Matthias Drochner <M.Drochner%fz-juelich.de@localhost>]

> Loadable fonts worked just fine on real vt220.  I still have
> collection of koi8 fonts for various fonts sizes somewhere (real dec
> vt220, tatungs that emulated vt220 but had taller glyphs, etc).

Yes a real vt220... The wscons_vt100 emulation doesn't claim
vt220 compatibility, and this is for a reason. There is just
too much graphics stuff involved, which doesn't map to the
wsdisplay abstraction, and can't be emulated on eg standard
PC character cell displays.
Also, to be vt220 compatible the fonts would have to be loaded
by a user program using the tty interface, and would have to
assume the character cell sizes as originally defined. That would
be too much to be of general use, and not appropriate for
a kernel implementation.

> wsemul doesn't provide the G0..G3 distinction

It does, as much as the vt100 did. One can map them to the
various DEC defined charsets, including the "national
character replacement" or so things.
It is just that no eastern languages were on DEC's radar
at that time.

> While the idea of the char mapping as used by vt100 emul is nice, the
> actual implementation is quite impractical, and evidence of 15+ years
> without properly localized console

The vt100 emul just tries to emulate a vt100 as good as practical.
(My initial motivation was to telnet into a DEC box or an embedded
system which doesn't know much more than a VT100. This works well,
including bus analyzers with waveform displays made of DEC
graphics characters.)
As said, if you want localization beyond what the original offered,
add another emulation to wscons.

And to prove the concept, I've just implemented one, called "ucons",
which is a copy of wsemul_vt100, with the DEC font mapping stuff
ripped out and replaced by UTF-8. It is a prototype, just deals
with UTF-8 sequences up to length 2, but good enough to be useable
with a "de_DE.UTF-8" locale.
And it didn't need a single change to font mapping code.

If you want to look at it: I've put two files up for FTP
at: ftp://zelof1.zel.kfa-juelich.de/pub/NetBSD/
wsemul.txt: a small patch to wscons which adds hooks to allow
loadable modules as terminal emulations
ucons.tar.gz: the console emulation, to be built as module
So to use it, call "wsconscfg -e ucons X" after loading the module,
and open a tty session on it the usual way, adding ttyEX to /etc/ttys.

best regards
Matthias



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