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.
Still better than the Amiga, where their was no memory protection at all. Basically the entire OS was built on sharing memory between processes through message passing...
This isn’t true. There are many modern features missing from RISC OS but memory protection isn’t one of them.
Each process sees its memory at the same logical address, it doesn’t have any way of accessing other process’ memory.
The process’ memory starts at the address 0x8000. http://www.riscos.com/support/developers/riscos6/memory/logi...