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CS439: Principles of Computer Systems

Homework 5, Part 1

Due: 8:45a Friday, February 28, 2014

Part 1 of the homeworks must be submitted electronically. Please refer to the homework turnin instructions.

  1. What are overlays? How and why were they created?
  2. What is a virtual address? What is a physical address? How do they relate to each other?
  3. What causes a memory exception? What is the end result for the running process?
  4. Pages have (at least) the following three bits associated with them: the resident bit, the clock/reference bit, and the dirty bit. Describe each bit and its use.
  5. In a 32-bit machine we subdivide the virtual address into 4 segments as follows:
     
    10-bit
    8-bit
    6-bit
    8 bit
    We use a 3-level page table, such that the first 10-bits are for the first level and so on.
    1. What is the page size in such a system?
    2. What is the size of a page table for a process that has 256K of memory starting at address 0?