"MS-DOS Prompt" problems in winvnc (win32)

James [Wez] Weatherall jnw "at" orl.co.uk
Mon, 23 Mar 1998 17:28:27 +0000

On Mon, 23 Mar 1998, Stane Bozic wrote:

> I installed vnc server on the 1st 32 machine and run vncviewer on the 2nd. 
> "MS-DOS Prompt"  in windowed or full screen mode 
> is not supported or anything must be set appropriately on the server side?

This is unfortunately Win32 platform dependent.  If you're running Windows
NT then the DOS boxes will actually work but won't output updates
correctly and so will have to be polled.  The default WinVNC settings
cater for this case.  If you're running Windows 95 then DOS boxes won't
work at all (i.e. you can't type into them)

> Vncviewer doesn't redraw MS-DOS windows correctly like other native win32 app windows. 

This is a server (WinVNC) side problem.  WinVNC can't hook MS-DOS windows
at all, so it has little or no idea what they're up to.  To get around
this to some extent, WinVNC has settings to allow such uncooperative
windows to be polled for changes every second or so.  This makes DOS boxes
usable at least, even if rather slowly.

> If MS-DOS window is put to full-screen mode then vncviewer loses its trace. 

There's no fix for this.  Windows puts the screen into a weird mode when
you do this, that WinVNC can't deal with.  This is a known limitation of

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