Tripple buffering glitch with Nvidia boards

Deathlike2 · Post by **Deathlike2** » Fri May 11, 2007 6:19 am

SDD supports the earlier NVidia hardware, prior to the TNT2.

riboflavin · Post by **riboflavin** » Tue May 15, 2007 9:31 pm

I've been tweaking pixels, refresh rates and sync-on-positive and negative values on VBEHZ. I've trying to find a rhyme or reason for why this glitch exists. As far as VESA displays go, I can't find any value that directly affects it.

In all this, I suppose I should mention that I've managed to stop it in Glaunch, which involved jacking up the resolution to 1024x768. Although ZSNES does not have that resolution, I was able to fake it out by changing the 800x600 VESA mode to the same resolution and refresh as the 1024x768 mode.

... ZSNES would still run, with the graphics a bit squished in the upper left, but the flicker would still appear after a few moments.

*sigh* I'm not QUITE ready to throw in the towel on this, but I'm not totally sure where to go from here. If any developers want to contact me to try a few things, I'm at your service.

-Riboflavin

riboflavin · Post by **riboflavin** » Sun Mar 02, 2008 10:00 pm

Am getting back to trying to find creative ways to fix this issue.

I thought it might be possible to fix by using some VESA tools. I've experimented with all of the following oldschool DOS video tweeking utilities...

VBEPlus
VBEhz
Nolfb
UNIVBE (scitech display doctor)
UNIRFRSH
FASTVID

... while some of these tools seem to cut down the frequency of the glitch, I still have not been able to find a way to eliminate it completely. The glitch itself can be so infrequent that testing a new combo of these TSRs can take a good deal of time of messing around in a game.

Just wanted to see if anyone had any new ideas to try. Thanks in advance!

Kajuru · Post by **Kajuru** » Sun Mar 02, 2008 10:57 pm

No more DOS versions, pal. We're alone.

Does the glitch happens from inside Windows(DOS port)?

riboflavin · Post by **riboflavin** » Sun Mar 02, 2008 11:13 pm

Good question. Let me try.

Alone... like the blackness of DOS itself.

Still... there has GOT to be a way to fix this. I'd be willing to dig into the source code if necessary.

Lemme check on that running the DOS version from windows idea...

riboflavin · Post by **riboflavin** » Sun Mar 02, 2008 11:33 pm

Well, interesting results.

640x480 Vesa 2 mode works as in DOS, but there is now a bunch of pixels stretched and smeared on the lower half of the screen. Hard to describe and I wish I could get a screenshot. After about a minute, I still did not see the flicker glitch, however.

320x240 Vesa 2 mode works well, but I did see it flash the glitch after about 16 seconds.

The lower resolutions seem to be more prone to the glitch than the higher resolutions in both DOS and when running the DOS version with Windows.

Hmm. I know that MAME has hardware triple buffering in dos that works with the Geforces without any flicker, so even if it is a fundamental problem with the hardware, it's possible to write code that can work around it.

Good suggestion tho. It did do something unexpected (pixel smearing).

neo_bahamut1985 · Post by **neo_bahamut1985** » Mon Mar 03, 2008 12:33 am

Huh. I have an nVidia card (7800 GT), too and I never had issues with triple buffering in Zsnes...But didn't you say the drivers were up to date...?

Deathlike2 · Post by **Deathlike2** » Mon Mar 03, 2008 12:58 am

neo_bahamut1985 wrote:Huh. I have an nVidia card (7800 GT), too and I never had issues with triple buffering in Zsnes...But didn't you say the drivers were up to date...?

They discussing specifically the DOS port which has "Simulated" Triple Buffering.

neo_bahamut1985 · Post by **neo_bahamut1985** » Mon Mar 03, 2008 5:34 am

Is there a reason he doesn't use the windows port? Just wondering...