From - err - memory, the OS used some of the memory protection in hardware, but it didn't use it with security in mind. I'm pretty sure an application could re

From - err - memory, the OS used some of the memory protection in hardware, but it didn't use it with security in mind. I'm pretty sure an application could rewrite important kernel tables below &8000. And if you were using any shared libraries, these were all implemented as kernel modules, with no guard rails. So it was kinda safe against some accidental access errors, but not at all a secure environment, and definitely possible to blow up the whole machine.