Assignment 1, due Aug 29

Part of the homework for 22C:60, Fall 2005
by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science

Always, on every assignment, please write your name legibly as it appears on your University ID and on the class list! All assignments will be due at the start of class on the day indicated, and unless there is what insurance companies call "an act of God" - something outside your control; the only exceptions to this rule will be by advance arrangement.

  1. What is your E-mail address? (If you have more than one, give the address you'd prefer used for class purposes.)

    Real Homework!

  2. Background: The ILLIAC I character code shown in Chapter 2 of the notes was punched on 5-level tape. That is, each character on the tape was recorded using 5 punching positions, representing 5 bits of data. There was a 6th punching position, but this did not record data, it only provided holes for the sprocket that pulled the tape through the tape reader.

    Question: The ILLIAC I code actually requires 6-bits per character because it allows representation of over 50 distinct codes. The least significant five bits of each character are encoded as punches in the paper tape. How is the sixth bit represented? (1/2 point)

  3. Give the UTF-8 encodings, in binary, for the following Unicode characters. (1/5 point each)

    a) The Roman capital S, Unicode character 005316.
    b) The Greek capital Sigma, Unicode character 03A316.
    c) The Cyrillic capital Es, Unicode character 042116.
    d) The Hebrew letter Shin, Unicode character 05E916.
    e) The Arabic letter Seen, Unicode character 063016.

  4. Consider this sequence of decimal numbers:
      78, 85, 76, 32, 61, 32, 48, 13, 10, 83, 79, 72, 32, 61, 32, 49, 13, 10.
    What 7-bit ASCII text does this represent? (1/2 point)

    Hint: Consider doing a decimal to binary conversion on each of the successive values and then looking them up in the ASCII character set table.

  5. Convert the above string of decimal numbers to octal. (1/2 point)

    Hint: Consider converting the binary numbers you computed above into octal.

  6. Show the 8-bit binary representation of -43 in each of the following signed number systems:

    a) Signed magnitude. (1/10 point)

    b) One's complement. (1/10 point)

    b) Two's complement. (1/10 point)

    b) Biased (with the natural bias for an 8-bit number). (1/5 point)