IBM used an external processor, they 8042 which was the keyboard interface, to reset the 286 on demand to go back to real mode. The 286 did have some quirks, bu

IBM used an external processor, they 8042 which was the keyboard interface, to reset the 286 on demand to go back to real mode. The 286 did have some quirks, but as far as I know none that allowed you to escape protected mode.