CSC103 How Computers Work
Take-Home

Due Friday 23 Oct 09 (by midnight)


Last Update:

This is a draft of the Take-Home Exam, the other option from the Paper. (You do only one or the other.) Both are 20% of your grade.

I view the Take-Home as roughly the equivalent of two assignments. So it will consist of about ten questions similar to those you have encountered in the assignments. It will range over the whole course.

Unlike assignments, you should do the Take-Home under the quiz rules: no collaboration, no help from the TAs, and otherwise open "book." Remember to cite sources for those questions that require online research.

 

  1. List what you feel may be the five most important contributions of Grace Murray Hopper to early computer developments. No need to explain each one at length; a sentence each would suffice.

  2. Binary

  3. Explain how the MP3 music format exploits the psychoacoustics of the human ear to achieve excellent compression without loss of audio quality. A clear and succinct explanation would be best.

  4. Suppose you have a 1 TB disk which has a rated sequential media transfer rate of 1 Gbps, and external backups are conducted over a 100 Mbps optic cable. How long at best would it take to back up your entire disk in a situation dominated by these three parameters? Show me your reasoning and calculations. Your answer should be in seconds.

  5. Design a circuit that takes two inputs A and B and produces the output as shown in the table below. The circuit should contain only copies of the gates AND, OR, and NOT. You may use as many of these gates as you'd like. Draw your final circuit by hand, or prepare it in the simulator and include a snapshot of that. Either was is fine with me.
    A: input
    B: input
    Output
    0
    0
    0
    0
    1
    1
    1
    0
    1
    1
    1
    0

  6. Design a circuit that takes two inputs A and B and produces the output as shown in the table below. The circuit should contain only copies of the gates AND, OR, and NOT. You may use as many of these gates as you'd like. This one might strike you as more challenging than the previous, but if you think of the conditions under which the output should be 1 and the conditions under which it should be 0, it should be feasible. If you cannot solve this or the previous, leave me some of your thinking for partial credit.
    A: input
    B: input
    Output
    0
    0
    1
    0
    1
    0
    1
    0
    1
    1
    1
    1

  7. When you dismantled your PC, you found batteries on the motherboard. What is the function/purpose of these batteries? A short answer suffices.

  8. I mentioned in class that there are some telescopes that correct for tiny atmospheric distortions by real-time altering the angles of tiny mirrors, effectively deforming their shape. Explain at least one method that such telescopes use to detect the atmospheric distortions which are then corrected. A clear and succinct explanation would be best. I am not looking for how the mirrors work in all aspects, just how the atmospheric distortions are figured out.

  9. Write a Scratch program to draw a series of nested squares, resulting in something like the snapshot shown below. If you can't get it to work correctly, at least submit something that shows that you gave it a good try, and I will assess partial credit.
    Squares

  10. Explain the connection between Moore's Law and the prediction that a technological "singularity" is in our future. Present one argument using Moore's Law that supports the singularity prediction, and one argument using Moore's Law that criticizes the predictions. There are many reasons to believe or disbelieve the singularity prediction, but I am asking here that you concentrate spefically on its relation to Moore's Law, both plus and minus. As usual, clarity and succinctness would be best.

Weightings of Questions:

Q# Weight%
1
10%
2
10%
3
10%
4
10%
5
10%
6
10%
7
5%
8
10%
9
15%
10
10%