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What is this 32-bit real mode mentioned in the official Intel x86 x64 manual?

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ben321:

--- Quote from: debs3759 on October 09, 2022, 04:20:07 AM ---https://en.wikipedia.org/wiki/Unreal_mode

--- End quote ---

I'm not completely sure that's what it refers to. Unreal mode is kinda a hack, not exactly something that an Intel manual would ever make reference too. Yet that one page of that one manual indicates the existence of a 32 bit real mode. Is it possible that this is something similar to, but not the same as the "unreal" mode? Maybe an undocumented feature who's existence just happened to accidentally get leaked on that one page in that one manual? Maybe you need to use an undocumented opcode to switch to it?

debs3759:
They are different names for the same operating mode. To set up segment selectors to use 32-bit addressing, you have to go into protected mode, set up the segments, then drop back into real mode with 32-bit segments. It's not strictly speaking documented (as you say, Intel barely mention it), but it is relatively easy. The second link I shared shows how to do it.

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