Consider two machines, a classical von Neumann architecture as well as a more modern machine with two buses: an internal memory bus and an input-output bus to which is connected a disk controller, a local area network interface card (NIC), a video card with a GPU, and the inputs from a keyboard and a pointing device. You are to trace the movements of bytes in RAM, cache, or on the disk drive within a page and a frame during a demand paged virtual memory page fault under several scenarios. The page in question contains both instructions ("pure text") and data (addresses that correspond to variables in a program, e.g., in C++, short int x;). You are to show at least the state of the machine and the state of any memory (including cache) and mass storage (e.g., disk) locations that may be involved. Explicitly explain what page replacement policy you are using, as well as how you are addressing cache coherency (if the machine has cache).

1 The classical von Neumann architecture.

2 The machine in question has no DMA and no cache.

3 The machine in question has no DMA but has a cache that can hold less than one page.

4 The machine in question has DMA but no cache.

5. The machine in question has DMA and has a cache that can hold 16 pages and uses a least recently used replacement algorithm for the cache.