There is emulation code for the PIC (interrupt controller) and PIT (timer) + various other stuff. The intcall86() filters out and handles INT 10h/13h/etc but everything else is emulated "for real": ip/cs/flags are pushed, new cs:ip set, etc.
There is an 8KB BIOS of some sort defined as a big array which should handle boot and hardware interrupts.
> Probably many more subtle bugs with the flags as well.
Sure. And lots of subtle bugs in general. Which is fine for someone's personal fun side project.
Since it's 286, can it run the cursed Xenix 286? Do hacked GDTs work?