Voodoo 5 Horizontal banding

Started by Razer357, 08 January 2023, 20:13:28

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Razer357

Hello guys. I've got a standard Voodoo 5 AGP that is showing horizontal banding when in 3dfx rendering. I first noticed it in Unreal Tournament (UT99) in 3dfx mode (3dfx mode only, DirectX mode is fine). I also started noticing it in other glide titles (ex. Need For Speed II SE). Knowing something about how the Voodoo 5 works, I believe it is an issue related to the internal SLI mechanism of slicing up the image to each chip for processing.

When I set rendering to one chip only, the issue goes away. If I enable antialiasing, the issue also goes away (strangely enough). Return to Castle Wolfenstein / Star Trek Elite Force / Quake 3 do not seem to exhibit any banding issues, but I think it is because they use OpenGL.

OS: Windows 98 SE
RAM: 512mb
CPU: AMD 3000+
Drivers: Amigamerlin 2.9

I looked over the board and it appears fine, but I guessing there is a component (maybe a cap) that needs replacing. I've done cap replacement before, so I'm not scared to do it, but wanted to ask if I am on the right track with my diagnosis before doing cap replacement?

Thanks.

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Glide

Hi Razer357, you're welcome.

About your Voodoo5's behaviour, I'm not 100% sure, but I'm dreading broken cap is not the root cause. Instead, I'm thinking to a VSA-100 graphics chip, because issue arises with Glide APIs only, while it is not present if chip executes other APIs/istructions.

Do coolers (heat spreaders and fans) of VSA-chips work both equally well?

To all: other ideas will be very appreciated obiouvsly. Thank you.

Bye bye

Razer357

Thanks Glide. I've got some new info, I just tested another 3dfx title, LucasArts's Outlaws, and I've found the issue doesn't actually go away when switching to single chip mode, it is only less obvious as the banding becomes much smaller.

I'm now wondering if one of my memory chips is bad, as switching to single chip mode doesn't eliminate the issue.

I think my plan will be to do the easy stuff first, recap is relatively easy. If that doesn't work, I may try replacing memory chips, although that is a much more difficult process and requires a steady hand and strong magnification.
 

Razer357

Ok I just did a lot more testing, changed drivers back to the last official beta ones, restarted a few times, and the banding seems to be gone from every glide app except Unreal Tournament 99. At this point I think it appears to be some software issue with the glide implementation in Unreal Tournament 99, as I can no longer reproduce any issues in any other glide application. Not sure why UT99 has this issue, but I can switch to the D3D driver for UT99 if I have to.

Maybe UT99 has an older implementation of Glide that I'm running into? idk.
 

Glide

Hi Razer357,

nice to know your problem is basically solved.

Unreal Tournament (99) mainly is a Glide APIs videogame, so I'm pretty sure you don't have software issue. However, at this point you could fully uninstall UT too, and perform a fresh installation (with or w/out apply latest 4.36 patch).

Have fun and thanks for your 3dfx passion.

Bye bye