Abstract
We modified the Java code of the MOSS simulator to develop a robust virtual memory simulator which allows the user to easily switch between different page replacement algorithms including FIFO, LRU, and Optimal replacement algorithms. The simulator clearly demonstrates the behavior of the page replacement algorithms in a virtual memory system, and provides a convenient way to obtain their page fault costs. We ran the simulator under various scenarios including random and mixed random-local memory access patterns. The results indicate that the Optimal algorithm produces the least number of page faults, LRU is general better than FIFO, and that FIFO behavior is unpredictable and illustrates Belady's anomaly.