4 ms·
I remember x86 real mode back in the day. Pretty hideous and hacky compared to what we have now.
by narrator 8y ago
I remember x86 real mode back in the day. Pretty hideous and hacky compared to what we have now.
- bvc35 8y agoWhat's real mode?
- gknoy 8y agohttps://en.wikipedia.org/wiki/Real_mode https://en.wikipedia.org/wiki/Real_mode
- saagarjha 8y ago> what we have now x86 processors still boot into real mode…
- yjftsjthsd-h 8y agoIt's my understanding that UEFI actually comes up directly into long mode? "UEFI firmware performs those same steps, but also prepares a protected mode environment with flat segmentation and for x86-64 CPUs, a long mode environment with identity-mapped paging. The A20 gate is enabled as well." - https://wiki.osdev.org/UEFI https://wiki.osdev.org/UEFI
- basementcat 8y agoThis inadvertently triggered my A20 gate rage.
- dlubarov 8y agoUnfortunately most BIOS services are only available in real mode, so it's often necessary to switch back and forth.
- ghamrick 8y agoI grew up (career wise) on CTOS systems with 286/386 processors that could address the full 16MB in protected mode without memory extenders or expanders that were available for DOS back in the day. Also premptive multi tasking. It was a great OS to learn on. more info - https://web.archive.org/web/20080828190425/http://www.byte.com/art/9412/sec13/art2.htm https://web.archive.org/web/20080828190425/http://www.byte.c...