Consider us even.... Now.
My post was poorly written. After " at least two
" years of looking, there does not seem to be a dos multi-tasker that fits my description. It seem Windows and Linux ( via Dosemu) are it.
There is DrDos7.03's Taskswitcher, that I haven't tried. But I doubt it would see the full system memory either. Its barely a version increment from the OpenDos version I tried.
I'll either pick one of the available mirco linux distros or build one myself. Then totally configure it focused on using Dosemu. It'll probably need to be something with an older Linux kernel. Maybe something from the 3 or 4 series. I'm not sure if Dosemu works with newer 5 series kernels.
Then I can choose to give Dos direct access to hardware or not; and which hardware. I know Win3x will run in Dosemu. Sometimes even Win95. From a glance, it looks like I can run Dosemu without X11 and allow Dos/Win to use the Video Card directly. But I haven't tried it yet. But I don't know if "Ctrl+Alt+function key" would work anymore. Or If it did, could I change back? For that X11 would probably work better?
It'd be a way cool project, that I just haven't gotten to.... yet.
Another great one, would be porting Dosemu to Grub2. Then I could just write thin hardware drivers for Grub2, per some yet to be defined specification aimed at Dosemu. But it would only be one instance of Dosemu at a time. The whole thing might not even be possible. But it would be a real great hypervisor, for retro folk. You could decide what drivers to emulate and which to use directly, with very low overhead. Then no matter what computer you used, you could have a Sounblaster and Nvidia Riva 128; providing someone wrote/writes the thin Grub2 drivers.
I don't image you would need to expose too much of a news gpu's 3D Accel. for translation from something like Dosemu's R128 emulation. But the emulation was probably written for X11/Mesa. <-Ouch
Anyway, I'd better wake up and get back to my day.