Almost all modern processors are recreations of the PDP-11 microprocessor, because that was the processor for which the semantics of the C programming language were based on. One of the distinctions the PDP-11 made was between the stack (memory area designated for variables and arrays whose structure was known before runtime) and the heap (memory area designated for arrays whose size can only be known during runtime; dynamic memory). The assembly of the PDP-11 treats stack memory and heap memory differently. In the 68k for the Sega Genesis, how is the distinction between the stack and the heap drawn? How is dynamic memory that can only be known at runtime managed?