> Yes, it does.  I/O under a DOS extender is measureably slower than under
> DOS.
Actually not much, unless the DOS-extender is of the sort which switches back 
to real mode, or uses normal V86 mode to use the BIOS interrupts.
> Sure they have.  Microsoft and IBM did one a long time ago called OS/2.
> Since then, Microsoft has done another called Windows NT.  A few years
> ago a guy named Linus Torvalds did yet another that's generally known as
> Linux.
Based on the BSD 4.4 Lite kernel, the FreeBSD project also did this.
> If you're asking about people writing a full-blown protected mode OS
> that attempts to follow the DOS model throughout, somebody might have,
> but I rather doubt it.  Anybody mentally ill to the degree that they'd
> want to is unlikely to have finished the job.
A better idea might be the use of unreal-mode and code-swapping.
> programs using reasonable machine resources, I'd consider it Nobel prize
> material.
Quite true, but consider the fact that many people /have/ already recieved 
the Nobel prize. Maybe it's time for somebody from 80xxx to be next? :)
 -- SPEED 2.00 [NR]: -- Lord Nihil -- This is a microsoft-free zone.
--- BBBS/NT v3.33 How
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