🚀 go-pugleaf

minar@reed.bitnet (Nelson Minar,(???)) writes:


>What exactly is 286 protected mode? Where can I read about programming it?
>Specifically, I am interested in how it handles addresses. I'm aware it can
>access memory greater than 1MB, so I presume it handles segmenting differently.
>What does it do?

>I also understand that MS-DOS doesn't function in protected mode. Does the
>BIOS? Are there MS-DOS like OSs that will work in protected mode?

286 protected mode is the mode that OS/2 runs in.  Almost any good '286
manual will talk about some of the differences, but the major one is that
the segment registers are now really "selector" registers, with the selector
table stored off in protected RAM.

Some of the BIOS will work in protected mode, however, don't plan on using
too much of it.  A good portion of it assumes that the interrupt vectors are
in segment 0, BIOS variables are in segment $40, the screen is at $Bx00, etc.
This is not necessarily true in protected mode, since sequential segments are
not necessarily sequential in memory.

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