Abstract:
Virtual memory (VM) is an imaginary memory uses disk space to extend primary memory (RAM). So the main memory can support multiprogramming which are simultaneously implemented without having all programs completed at that moment in real memory.
Concentration on the demand paging as an application used in the virtual memory is to be presented and that; never to load a page in the memory without being asked for at this moment.
The Least Recently Used (LRU) algorithm is discussed for changing and choosing an empty space in the real memory for loading information.
A C++ (VM) simulation program is written for the LRU algorithm for counting the number of uses of the page and choose least one used and swap it to the disk and that is emptying its space for entering the would page for executing another program.
The program gives satisfactory results.
