Part 5: DMA I-O frees the CPU to do other work while an I-O operation is pending. Using DMA I-O requires more complex controller hardware and more complex bus. In addition, there is an operational penalty; that is, a disadvantage that shows up while a DMA I-O operation is in progress. Explain what it is.

Part 6: Cache memory is faster than main memory, but also much smaller. In general, cache memory is not large enough to hold all of an executing program. In about a paragraph, explain how cache memory is able to speed up the execution of programs. Just naming the principle involved is not enough; you must explain it.

Part 7: When a cache miss occurs on a memory read, the cache controller and memory take three major steps, assuming that the cache has no free cache line when the miss occurs. List and briefly explain each one in the order they occur.