woooohooo i found the answer. Just installed experimental version of dosbox with 2xsai shader patch from there http://www.si-gamer.net/gulikoza/. Thank you so much gulikoza if u ever will read this topic !!!!!!!!!!!!!!

I'm glad it works 😀

I am pretty sure to have seen some tiny example code (in Turbo Pascal) done by someone in the demo scene to enable VSYNC. Maybe someone did make a TSR.

You can't enable v-sync from inside Dosbox via a TSR because it's caused by SDL or the graphics drivers.

hm it works with that no desynchronization, but then sound break off.

Yea because most of the time is wasted waiting for vsync.

I don't have any problems with fulldouble on my desktop computers. My laptop doesn't like it though. Must be an SDL/driver problem.

By the way, wouldn't triple-buffering eliminate having to wait for v-sync?

Also, some games such as System Shock and Heretic show tearing even with fulldouble (it shows up on screencaptures and recorded videos too). Are those games simply not programmed to wait for v-sync?

SDL can't do triple buffering...

By the way, "SDL 1.2.6 has added experimental retrace-synchronized software "flipping". You access it by using SDL_DOUBLBUF|SDL_HWSURFACE|SDL_FULLSCREEN passed to SDL_SetVideoMode. SDL_Flip() will return immediately and the flip will be performed asynchronously in a separate thread." so doublebuffering shouldn't slow down Dosbox.

Not every hardware might be capable of doing that asynchronously (the other thread using 100% CPU while waiting). It slows down for me a lot.

ripa wrote:

By the way, wouldn't triple-buffering eliminate having to wait for v-sync?

Yes and no:
http://www.anandtech.com/video/showdoc.aspx?i=3591