Comment by maybewhenthesun
8 hours ago
Amen to that!
I think I remember there was some communication between ID and Charles Sandmann about CWSDPMI, so even though it's worded a bit strange for an open source project there's probably some thruth in it?
Also a bit strange how the author is surprised about Quake running in a 'VM', apparently they don't really know about VM86 mode in x86 processors...
It's a bit surprising because this is the author of the DooM Black Book and they know the underpinnings pretty well.
However, the difference between a DOS VM under Windows 9x and a Windows command prompt and a w32 program started from DOS is all very esoteric and complicated (even Raymond Chen has been confused about implementation details at times).
DPMI clients don’t run in a VM, though. They’re just a normal task like any other task / process in Windows.
So... Win32 runs in virtual mode. In 2025, we don't think of that as a Virtual Machine, but it totally is. Hardware access is trapped by the CPU and processed by the OS/DPMI server.
No, in 386 mode 3.x and 9x the System VM and other DPMI clients runs in protected mode.
Virtual 8086 mode, as its name somewhat suggests, only runs real mode code.
I think if you're relatively young is hard to know computing history. Its oddly older than one thinks, even concepts that are seen as new. Its sometimes interesting to see people learn about BBS's which flourished 40 years ago.