3 ms·
Interesting, I wasn't aware that you could use them in protected mode and they were 32-bits wide from the 386 on-wards. It also reminded me of something else: I
by weinzierl 7y ago
Interesting, I wasn't aware that you could use them in protected mode and they were 32-bits wide from the 386 on-wards. It also reminded me of something else: I think Tanenbaum discussed the advantages of the segmented memory model in his operating systems book, but I never paid attention because coming from the 16-bit word I immediately dismissed that idea. I might have to reread that chapter...
- Taniwha 7y agoIt's worse than that, you can set up 32-bit segments in 32-bit mode, then switch back to 16-bit mode and have them do vaguely sensible things .... This wasn't defined by Intel, but Windows went on to depend on this feature in order to boot (to access PCI) (I was once involved in an x86 clone project)
- EvanAnderson 7y agoFor anybody who is curious, this is colloquially referred-to as "unreal mode": https://en.m.wikipedia.org/wiki/Unreal_mode https://en.m.wikipedia.org/wiki/Unreal_mode