Re: [Qemu-devel] qemu kbd emulation

[Oliver Gerlich <olig9@gmx.de>]

Rafał Cygnarowski wrote:
> Hi!
> 
> I wanted to correct qemu emulation of keyboard under DOS as 
> guest OS, so I started with simple pascal program to check 
> what happen on guest DOS (and DOS) when I press up/down/left/right 
> keys.
> 
> The program was:
> 
> -- BEGIN test.pas --
> program time; {$M 2048,0,0}
> uses crt, dos;
> var OldKeyInt : procedure;
> 
> procedure NewKeyInt; interrupt;
> begin
>         write(Port[$60]); write(' ')
>         inline($9c); OldKeyInt;
> end;
> 
> begin
>         getintvec($9, addr(OldKeyInt));
>         setintvec($9, @NewKeyInt);
>         keep(0);
> end.
> -- END test.pas --
> 
> and it look that qemu does not generate some codes before 
> pressing and after releasing arrow keys. For example pressing 
> up key on qemu looks like:
> 
> 224 72 224 200
> 
> while without emulation it looks:
> 
> 224 42 224 72 224 200 224 170.
> 
> It's true only for single keystrokes, but good for the 
> beginning.
> 
> So I tried to patch qemu for this and created following patch:
> 
> -- BEGIN sdl.patch --
[snipped patch]
> -- END sdl.patch --
> 
> Unfortunatelly results of this patch completely suprised me. After this patch 
> my test program produces results witch are impossible to produce in normal 
> situation. Example output for UP key was:
> 
> 224 224 72 88224 224 170.
> 
> What's wrong with this patch? What I'm doing wrong?
> 
> Regards,

What SDL version are you using? I noticed some strange keyboard behavior 
with SDL 1.2.9 (Debian package), and this didn't happen when using SDL 
1.2.10 (self-built). The problems were things like no Shift-Tab in 
Windows, and "showkey" under Linux displaying strange keycodes when 
using Shift-Tab.

Regards,
Oliver