All those cards can do modes 12 and 13h. I can do it on a GTX 660. Doing it in QBASIC inside NTVDM is a different question. I think you need to clarify your requirements. What language version of Windows are you running and do you want DOS programs to run full screen or in a window?

Running QBASIC in NTVDM is kind of unpleasant in general because it pegs a CPU core at 100%. Dosbox might be better. (Or use QB64 or FreeBASIC.)

bakemono wrote on 2025-02-08, 08:41:

All those cards can do modes 12 and 13h. I can do it on a GTX 660. Doing it in QBASIC inside NTVDM is a different question. I think you need to clarify your requirements. What language version of Windows are you running and do you want DOS programs to run full screen or in a window?

Running QBASIC in NTVDM is kind of unpleasant in general because it pegs a CPU core at 100%. Dosbox might be better. (Or use QB64 or FreeBASIC.)

I had read somewhere that as UEFI was becoming more popular over the years that older VBIOS and VESA modes were being retired, but I will take your word for it re. a GTX 660. Perhaps there is something I have overlooked.

Typically what I would do is boot into Windows XP, and then run QBasic (4.5) fullscreen via NTVDM; Indeed, this would be the same for any 16 bit MS-DOS application or game, such as Doom or Skyroads (both 13h).

I want DOS programs to run fullscreen, as they would under real MS-DOS. As my original post suggests, this was all possible with the GeForce 8600GT, but failed with anything newer (except the Quadro K4000 which surprisingly sort of half worked).

There are reasons I have shied away from DosBox and QB64. Generally speaking, they don't feel like the real thing.

As you suggest, 12h and 13h work on a GTX 660. Maybe there are some more modern cards that maintain legacy VGA modes for a long time? Could you elaborate more on what I might have overlooked regarding 12h and 13h?

ONIXLabs wrote on 2025-02-08, 10:18:

As you suggest, 12h and 13h work on a GTX 660. Maybe there are some more modern cards that maintain legacy VGA modes for a long time?

I just checked and both of these modes seem to work on my Nvidia T600 – a glorified GTX 1650. I was able to enter them from DR-DOS debug without issues.
3DBench, Quake, UltraForce's Vector Demo and Wolfenstein 3D ran perfectly. "Well, UltraForce did it on your PC!"
Even Mario & Luigi displayed without any artifacts, which surprised me - this game stutters on my GTX 750 Ti and fails horribly on recent AMD/Intel integrated graphics.
Impact Studios' Realtime mostly runs at 320×200 with 256 colours, but occasionally switches to mode 12h to display some fancy still images. The demo exhibited jerky scrolling in the intro, which happens to use text mode. Besides that, it ran fine.
LineWars II got past the logo, but then displayed a grey screen instead of the mission select menu.
Windows 3.1 works at 640×480 with 16 colours (mode 12h), albeit with plenty of artifacts.

P.S. In an attempt to see if I could get the Quadro K4000 and Quadro FX 3800 working with screen modes 12h and 13h, I flashed the VBIOS firmware with both older and newer roms to see what would work. Unsuccessful on both counts. They are now bricked and can be donated to a museum.

What's wrong with flashing them back?

I just checked and both of these modes seem to work on my Nvidia T600 – a glorified GTX 1650. I was able to enter them from DR-DOS *debug* without issues.

I wonder then what it is that I'm overlooking...perhaps it's more of an issue with NTVDM itself, than with the cards?

Windows 3.1 works at 640×480 with 16 colours (mode 12h), albeit with plenty of artifacts.

What sort of artifacts did you experience?

What's wrong with flashing them back?

I'd hazard a guess that to flash them back, I'd need a motherboard with more than one PCIe x16 slot. I don't have a PC like that anymore...well, I do, but it's a Mac Pro, and I very much doubt it would be a good idea trying to install Quadro cards in a Mac Pro.

Alternatively, if there is a way to script the flashing process, and perform it from a bootable floppy disk...that might work.

ONIXLabs wrote on 2025-02-08, 21:10:

I wonder then what it is that I'm overlooking...perhaps it's more of an issue with NTVDM itself, than with the cards?

It depends on the video drivers, the language mode, and probably some other things. With US codepage, the text screens of QBASIC and QuickBASIC work for me both in a window and full screen. If I change to SCREEN 13 it goes full screen automatically. With Japanese code page, the programs have some wrong characters when running in a window, which is fixed when switching to full screen, but the programs won't launch at all if I'm already in full screen...

You'll likely need to use the videoprt patch (2000/XP) if you are having issues with VESA resolutions under NTVDM that work find on DOS on the same machine.
Re: Memory for protected mode DOS games
Re: No video when running MS-DOS games in full screen

Whilst it doesn't fully support running 16 bit MS-DOS applications (maybe it supports text mode 0...I don't remember), at least modern browsers still work in Windows 7.

NTVDM in Windows Operating systems up to 10 32bit support 16bit applications just fine.

As long as you are using XPDM video drivers (not WDDM) in Windows 7 then fullscreen works. You might encounter the resolution issue that requires the videoprt patch but I don't remember if anyone coded an equivalent for a Windows OS higher than XP or if the issue still existed/exists. solvbe/dgvoodoo might work but they were flaky last time I tried years ago and since development never continued I don't see that as having changed.

There are reasons I have shied away from DosBox and QB64. Generally speaking, they don't feel like the real thing.

NTVDM isn't the real thing either. Use the tools that work best for what you want to do. Leave the feelings out of it.

ONIXLabs wrote on 2025-02-08, 21:10:

I just checked and both of these modes seem to work on my Nvidia T600 – a glorified GTX 1650. I was able to enter them from DR-DOS *debug* without issues.

I wonder then what it is that I'm overlooking...perhaps it's more of an issue with NTVDM itself, than with the cards?

Nvidia most likely neglected the NTVDM in their later drivers. I also experienced graphical corruption upon entering these modes on a Quadro FX 2700M with Windows 2000.

What's wrong with flashing them back?

I'd hazard a guess that to flash them back, I'd need a motherboard with more than one PCIe x16 slot. I don't have a PC like that anymore...well, I do, but it's a Mac Pro, and I very much doubt it would be a good idea trying to install Quadro cards in a Mac Pro.

My original Asus Maximus Extreme has three PCIe ×16 slots. Not only that – each one can run at full speed! They simply don't make these boards like they used to...

Windows 3.1 works at 640×480 with 16 colours (mode 12h), albeit with plenty of artifacts.

What sort of artifacts did you experience?

Windows renders dark boxes in places where they shouldn't be – usually on the sides of each window. Windows 95 exhibits the same issue on recent video cards; I've seen it both in videos and on real hardware. Here's a mock-up of what it looks like:

GemCookie wrote on 2025-02-14, 18:00:

Nvidia most likely neglected the NTVDM in their later drivers. I also experienced graphical corruption upon entering these modes […]
Show full quote

ONIXLabs wrote on 2025-02-08, 21:10:

I just checked and both of these modes seem to work on my Nvidia T600 – a glorified GTX 1650. I was able to enter them from DR-DOS *debug* without issues.

I wonder then what it is that I'm overlooking...perhaps it's more of an issue with NTVDM itself, than with the cards?

Nvidia most likely neglected the NTVDM in their later drivers. I also experienced graphical corruption upon entering these modes on a Quadro FX 2700M with Windows 2000.

What's wrong with flashing them back?

I'd hazard a guess that to flash them back, I'd need a motherboard with more than one PCIe x16 slot. I don't have a PC like that anymore...well, I do, but it's a Mac Pro, and I very much doubt it would be a good idea trying to install Quadro cards in a Mac Pro.

My original Asus Maximus Extreme has three PCIe ×16 slots. Not only that – each one can run at full speed! They simply don't make these boards like they used to...

Windows 3.1 works at 640×480 with 16 colours (mode 12h), albeit with plenty of artifacts.

What sort of artifacts did you experience?

Windows renders dark boxes in places where they shouldn't be – usually on the sides of each window. Windows 95 exhibits the same issue on recent video cards; I've seen it both in videos and on real hardware. Here's a mock-up of what it looks like:

Those artefacts were exactly what I experienced with the Quadro K4000.

I've now installed a Quadro FX 1800, which is nowhere near as powerful, but for the era, it's certainly enough. I can run QBasic, and DOS applications in 12h and 13h without an issue, and it supports 2560x1600 over a DisplayPort cable.