WinVNC Server/ Java applets

James [Wez] Weatherall jnw "at"
Wed, 01 Jul 1998 13:38:03 +0000

On Wed, 1 Jul 1998, Wayne wrote:

> What I presume is needed is a way to tie VNC into the display driver, in a
> fashion, that will enable remote access via terminals.  Looking at
> Tarantell, it has its own driver, so to speak, that translate any X or CHARM
> content via Java to a viewable content whether it be a Web browser or a
> purpose built interface.

Basically, yes, this is the difficult bit of WinVNC.  It may be possible
in future versions of Windows NT to hook in more directly to the OS, in
which case the performance will improve significantly.

> I appologise if it sounded as though I was trashing VNC, but I believe
> the speed issue is a valid point.  I tried using a web browser, but gave
> up because it took so long to refresh via the Java interface, however
> via the X interface it flew.  It handled DirectX screen wierdly but they
> were still usable to a certain degree. 

That's fair enough.  I think the main problem in using the Java viewer at
present is that it has to work around some bugs in most JVMs, most notably
the one which makes it impossible to blit raw pixel data to the display
reliably - most JVMs don't byte-swap the pixel data as required, so the
colours get messed up for raw data and VNC has to plot each individual
pixel to get round this.

Hmmm.  What sort of Direct X thing were you using and what weirdness did
you see?  There are some bugs in existing releases that make 256 colour
displays look wrong but which are now fixed, if that's the problem you


James "Wez" Weatherall
Olivetti & Oracle Research Laboratory, Cambridge, UK.
Tel : Work - 343000

The VNC mailing list     -   see