You can't, at least safely. If you can write arbitrarily to any position in RAM then it's not a memory-safe language. You can hide accesses behind some kind of

You can't, at least safely. If you can write arbitrarily to any position in RAM then it's not a memory-safe language. You can hide accesses behind some kind of abstraction (unsafe blocks, libraries or whatever). But that's not a memory-safe language, it's the developer making a contract with himself agreeing to not allowing direct, straight accesses (like those caveats we C/C++ developers do to not make "memory bugs"). Some microcontrollers can protect certain memory areas and raise access faults, but those are the same faults for a program written in C, C++, assembler, etc., and not related to the language. One make the safest RTOS in trendy-safe-lang for some small microcontroller, but the end-user (developers) would still be able to write some unsafe code and blow a fuse. A different thing is for MCUs with MMU and/or an OS that handles virtual memory per process/thread, but that wasn't your question.