The driver is both DOS & Windows 3.1 😀
The "Video II" application is the only app installed when you run the installer for Windows (3.1).
When you run the Video II app, it bypasses VFW completely and just directly configures the card. Maximize the window (or use its "full screen" which even paints a little 4-pixel square bezel), it configures the card to blast nearly the full screen. The software just draws the canvas as pink, but once the capture card starts, it replaces pink with the video. So I put MSPaint over the window, and can draw video in pink 😉
Today I experimented with Video for Windows (1.1e) and the VFW capture driver. I got a terrible video capture (160x120 at ~15 FPS). The card has no sound of its own, so I piped audio into my Ensoniq Vivo 90, which ... is a Windows 95-era card with very limited Win3.x support. Couldn't control the audio volume, got ear-blasted recording (despite piping it through to speakers just fine).
Moved over to Windows 95, installed the Win3.1 VFW driver, and it was ... distorted (doesn't paint the overlay into the right place, possibly due to running at 800x600 resolution), but it captures audio well. Encountered more issues with the system (disk I/O hangs, possibly format-related as I've got a stack of weirdness on here including a VL-Bus IDE card), gave up for now.
Will come back to it this evening, but hopefully I get a good capture soon.
For now, here's the first capture (originally 128MB of uncompressed frames... ffmpeg'd it down to h264). Warning: audio has been reduced by 90% but it'll still jumpscare you.
The attachment TEST_discord.7z is no longer available
(Forum doesn't accept *.mp4 so I had to pack it in a 7z)