cde wrote on 2020-07-10, 19:21:
Many thanks Darry for your tests. Am I correct to assume the Geforce FX 5500 should be able to accept 1600x1200@70 Hz, considering the max. resolution is 2048x1536? If so, then I suppose the BIOS is for some reason rejecting this custom resolution even though the hardware is capable of handling it.
I'm also sad the Radeon 9200 refused it. Do you have by any chance have an AGP 9250 to test this resolution with? In my case it accepted 1280x960@70Hz, although I admit it's a much lower pixel clock. 1600x1200 is an interesting resolution since it's a perfect scale from 320x200. I also tend to prefer the Radeon, as they don't have that blur effect that most GeForce 4 & 6 cards apply (with GeForce 4 being the worst).
I was expecting the FX 5500 to work and 1600x1200@70Hz, but it unfortunately did not . The hardware is capable, AFAIK . The FX 5500 and FX 5900 have one major difference in terms of DVI output in that the FX 5900 (also the FX 5900XT and possibly all other FX 5900s) uses a discrete TMDS chip (usually from Silicon Image or Thine) and likely has different resolution selection logic in its BIOS than the FX 5500 has in its BIOS .
I unfortunately do not have an AGP Radeon 9250 to test (as far as I know, I have some stuff in storage) . I am not crazy about Nvidia scaling either .
The reason I am not running more tests on Radeons is because the have issues in certain demos, like Second Reality .
My current "best" solution for running 70Hz in DOS is a Voodoo 3 connected to the VGA input of an OSSC, which outputs 720x400@70Hz over DVI into a CYP CP-254 that scales it to 1024x768@70Hz which is in turn scaled to 1600x1200@70Hz by my monitor (Unfortunately, the CYP CP-254 does not accept 640x400@70Hz) . This is not optimal, but preserves aspect ratio (which my monitor does not do for 640/720x400@70Hz) and still gives a sharper picture than the Geforce FX's scaling . I am waiting for a CYP SY-P293 as possible short term improvement. The long term solution is an OSSC Pro .