First post, by tovwiv

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New poster here, hope I'm in the right forum. I've been following the work of others who are experimenting with Vortex86 SBC/SoM setups for some retro gaming. I snagged a PC/104 board with a Vortex86DX w/ onboard video. Normal DOS resolutions work fine over VGA with my Flat Panel LCD (Dell U241). (With the exception of Flashback Quest for Identity which seems to use an odd resolution that clips the left side of the screen and VESA DOS modes also appear to not work).

The onboard XGI Volari chip should support resolutions up to 1024x768. However in Win98 I am unable to view the entire screen when exceeding 640x480. Any resolution higher results in screen clipping (see screenshots). Windows seems to think it's operating at the correct resolution, although my monitor only detects 640x480.

Things I've tried:
- I've tried all version of XGI video drivers I could get my hands on R1.13, R1.14, and some Beta drivers posted by Rasteri.
- Cheapo VGA/HDMI upscaler
- Ensuring EDID pins aren't connected (actually my PC/104 version of this board has all VGA pins other than R,G,B,HSync,Vsync tied to Ground)
- Various monitor profiles in Win98 including the official one from Dell
- Different VGA Source. My XP era laptop outputs 640x480, 800x600, 1024x768 (and higher) with the same VGA cable/port/monitor without issue.

The only thing I can think of is the odd choice of not connecting the EDID/DDC pins is causing the video chip to ignore VESA resolutions. Or there is some difference with the SBC version of this setup vs the SoM that Rasteri and others are using.

Any ideas on what else I can try? Thanks!


Last edited by tovwiv on 2022-03-06, 20:16. Edited 1 time in total.

Reply 2 of 4, by Paul_V

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I've never tried running Win98 on Vortex86DX, only pure DOS. But I'll give a try on ebox-3300 mobo.
Can you specify the pc\motherboard model? Some motherboards have bios settings, which lock the resolution output to a specific value.
The other thing that comes to my mind is using drivers from vmware tools win98 package.

Reply 3 of 4, by tovwiv

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Hey Paul_V, thanks for the offer to help! I've actually been able to solve the issue since I originally posted this thread. It was a little complicated but your thread here Vortex86DX - A beastie of it's own (General info and discussion) led me down the right path. I'll post what worked for me in case anyone ever needs this in the future.

I used BIOSMP to dump the bios on my VDX-6354RD (ICOP board), after inspecting it, I found some hints that this board was loaded with a custom BIOS before I got my hands on it. My theory is it was used in an embedded device and had been configured for Flat Panel/LVDS output via a header on the board. I emailed ICOP to confirm and asked if they would pass along the latest official BIOS for this board.

In the interim I was too impatient, so I rolled the dice.

  • I used the AMI MMTOOL to extract just the video card ROM from the 6390RD BIOS that Mumak posted in the thread mentioned above.
  • Using the MMTOOL again I replaced just the video ROM in the BIOS I had extracted from the board in my possession.
  • After double checking everything, I then I flashed the modified BIOS using BIOSMP.

To my surprise upon a reboot the VGA signal started behaving as it should and will actually switch into high resolutions. (According to the file header, the XGI video ROM from the 6390 was actually a slightly newer version than what I had originally).

I thought about flashing the 6390RD BIOS directly without modification, but figured there was a larger potential of things going sideways.


Reply 4 of 4, by Paul_V

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Glad you got it sorted out. Thank you for the info.

Makes me wonder, if there is a AMI BIOS version, which allows switching video modes (CRT\LCD 640x480; 800x600 etc).
Otherwise, there will always be trouble upscaling things correctly.
Advantech BIOS, for example, does have this, but lacks many other options.

And yes, flashing these things is a big leap of faith for now. I got nothing concrete yet about it's JTAG port and how to unbrick the BIOS in case of failure.

I've installed Win98 anyway (Oh boy, have I lost my touch with these OS's !)
The first supermicro drivers I found on the net did work OK (Z9s were widely used as server video chips)
Maximum possible resolution 1600x1200 for this chip is also working fine on LP2065, but is a blurry eyestrain.
I can't say whether this is a vga shielding issue or just the limitation of an interface.


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