Hi I'm having some trouble with a project that I'm working on that requires me to use the old DirectX 6.1 SDK. I soon realized that all display modes work except those using a resolution of 2560x1600 where D3D::CreateDevice returned DDERR_INVALIDOBJECT. 2560x1600 is the native resolution of my display and I've never experienced any problems running new games at this resolution. I checked the SDK samples for D3DIM and found out that all of them would fail the call to CreateDevice when the resolution was set to 2560x1600. Does anyone here know if this is some kind of limitation in DX6.1 backwards compability that it is not able to initialize a 3D device at this particular resolution or what could be the problem? I'm using a GeForce 8800GTX card on Windows XP with the latest drivers and DirectX 9.0c installed.

Have you tried in any other wide resolution?
To me all calls to CreateDevice fails with resolutions having a wide aspect ratio.

Savage

Yes, all other wide-screen resolutions that my display support seem to work including 1280x800 which is half of 2560x1600.

Other wide-resolutions that I've tried are:
1280x720
1280x768
1280x800
1360x768
1600x900
1680x1050
1920x1080
1920x1200

I can't find any info to help me from hours of googling either so I suppose I'll just have to let it be. As you say there's not a lot of support for tech that's 10 years old. Even finding a downloadable copy of the SDK took forever.

Thanks for your help and Happy New Year (although a bit late)!