[9fans] X device

[Russ Cox rsc@plan9.bell-labs.com]

> The other possibility that came to mind was implementing a
> VNC server for Plan9. That would allow users of Unix/Doze/NT/Mac
> to pull up a Plan9 system on their screens without having to
> have a copy of the OS to run..

Even though
> VNC goes to show that what the world really desires are Yet More
> Stupid Protocols.

it is a neat hack, in that it would be a pain to rewrite
most of the window systems (X, MS-Win) to generate any other
protocol, be it /dev/bitblt or something else.  Instead, what
they've done is very inelegant but appears to work decently.

I think that writing a VNC server for Plan 9 could be done
quite easily, actually: write something to translate /dev/bitblt
commands into a VNC transcript of sorts, and then send whatever
part of the transcript the client hasn't seen yet.  You could
run a different 8.5 for each VNC session.  The method I have
in mind would maintain the screen bitmap in memory (so that, say,
if the VNC client asked for the whole screen you could give it)
but also kept the VNC transcript.  Very little overhead...
Mouse cursor changes seem to be a problem, but overall it might
be an easier than trying to make 9x work (only because someone
already has a VNC X client).

It seems like a Plan 9 VNC client would be even simpler: I'm
guessing five to ten pages of code at most.

The real question is whether VNC actually feels decent enough
to use.  Is it a good enough hack?
I don't know the answer to that since I haven't tried it.

Russ