VOGONS


First post, by ShovelKnight

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I recently ran into a problem with my Super Socket 7 retro PC. I want to use a GeForce 2MX PCI graphics card in this build, but I can't get some DOS applications that use SVGA video modes to work with this video card.

Most notably, both PC Player Benchmark and Chris' 3D Benchmark don't work in 640x480 with the GeForce. When I run PCP, the screen turns black but the monitor stays turned on; I can't quit the application but I can soft-reboot the PC with Ctrl + Alt + Del. When I run Chris' 3D Benchmark, the monitor shows "No signal" and goes to sleep, and the only remedy is to hard reset the PC. Both benchmarks run perfectly in VGA.

SEA (an old shareware image viewer for DOS which displays images at 640x480 in hi color) also doesn't work with the GeForce, the screen flashes blue then goes black and I have to press Ctrl + Alt + Del to reboot the PC.

I know that the PC Player Benchmark uses VESA mode 0101h (640x480/8bpp). Chris' 3D Benchmark appears to use mode 0111h (640x480/16bpp). Both modes work perfectly when tested with Rayer's VESATEST utility, with both bank switching and LFB.

The issue is NOT related to write ordering and write combine because I get exactly the same results even if I don't use setewb and k6wcx to enable write ordering and write combine.

I tried two other graphics cards (ATI Radeon VE AGP and SiS 6215 PCI) and the problem is not present with these graphics cards. However, the Radeon has noticeable problems in some games (Ultima VII, Prehistorik 2) and the SiS is just a slow piece of junk.

I wonder if there is anything I can do to avoid the issue... 😵

System specs:

- AMD K6-III+ running at 550 MHz
- Shuttle HOT-597 motherboard, VIA MVP3 chipset (but the same problem is present on Gigabyte GA-5AX with ALi Aladdin V)
- 384MB PC133 SDRAM
- 32GB IDE SSD
- ESS ES1869FC sound card

Last edited by ShovelKnight on 2019-11-12, 13:45. Edited 1 time in total.

Reply 1 of 6, by ShovelKnight

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What I tried so far:

- vesa12 (to block VESA 2.0 and 3.0 modes)
- VBE Plus
- Scitech Display Doctor (which says that my GPU is not supported but I can enable it anyway)

nothing works 🙁

Reply 3 of 6, by Cyberdyne

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Usually if in dos something is wrong, et problem is with a memory managers etc... maybe you will show us your config.sys and autoexec.bat.

I am aroused about any X86 motherboard that has full functional ISA slot. I think i have problem. Not really into that original (Turbo) XT,286,386 and CGA/EGA stuff. So just a DOS nut.

Reply 5 of 6, by ShovelKnight

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So... I noticed that those apps are 32-bit protected mode DOS apps. In DOS, they rely on a DOS extender to run. DOS extender is not required under Windows because Windows already provides DPMI services to DOS applications.

This was the right line of thinking, because SEA and PCPBench were cured by replacing DOS4GW with DOS32A, and Chris' 3D Benchmark was fixed by replacing its stock CWSDPMI.EXE with the latest version.

I have no idea why those old DOS extenders are incompatible with this particular video card, but here we are.