Goals

This assignment checks your understanding of the material in P&H Chapter 1 as well as some number representation basics. It will also give you practice compiling and executing C programs.

Background reading

• K&R: Chapters 1-4
• P&H (4th): Chapter 1, Chapter 2 section 4, section 5 (only the hexadecimal numbers)
• Also be sure you understand Lab 1 Exercise 4

Submitting Your Solution

Submit your solution by creating a directory named hw1 that contains files named cod.txt and majorbit.c. (Note that capitalization matters in file names; the submission program will not accept your submission if your file names differ at all from those specified.) From within that directory, type "submit hw1". Partners are not allowed on this assignment.

Problem 0

  $ mkdir ~/hw
  $ cp -r ~cs61c/hw/01/ ~/hw

Problem 1

In cod.txt, answer the following questions:

P&H (4th) problems 1.1.1-1.1.26 (these are very short questions), reproduced below:

Find the word or phrase from the list below that best matches the description in the following questions. Use the numbers to the left of the words in the answer. Each answer should be used only once.

1. Computer used to run large problems and usually accessed via a network.
2. 10^15 or 2^50 bytes.
3. Computer composed of hundreds to thousands of processors and terabytes of memory.
4. Today's science fiction application that probably will be available in the near future.
5. A kind of memory called random access memory.
6. Part of a computer called central processor unit.
7. Thousands of processors forming a large cluster.
8. A microprocessor containing several processors in the same chip.
9. Desktop computer without screen or keyboard usually accessed via a network.
10. Currently the largest class of computer that runs one application or one set of related applications.
11. Special language used to describe hardware components.
12. Personal computer delivering good performance to single users at low cost.
13. Program that translates statements in high-level language to assembly language.
14. Program that translates symbolic instructions to binary instructions.
15. High-level language for business data processing.
16. Binary language that the processor can understand.
17. Commands that the processors understand.
18. High-level language for scientific computation.
19. Symbolic representation of machine instructions.
20. Interface between user's program and hardware providing a variety of services and supervision functions.
21. Software/programs developed by the users.
22. Binary digit (value 0 or 1).
23. Software layer between the application software and the hardware that includes the operating system and the compilers.
24. High-level language used to write application and system software.
25. Portable language composed of words and algebraic expressions that must be translated into assembly language before run in a computer.
26. 10^12 or 2^40 bytes.

P&H (4th) problems 1.2.4:

Assuming that a cache memory is ten times faster than a DRAM memory, that DRAM is 100,000 times faster than magnetic disk, and that flash memory is 1000 times faster than disk, find how long it takes to read a file from a DRAM, a disk, and a flash memory if it takes 2 microseconds from the cache memory?

P&H (4th) problems 2.7.1, 2.7.2, 2.7.5:

The following problems explore number conversions from signed and unsigned binary number to decimal numbers.

2.7.1. For the patterns above, what base 10 number does it represent, assuming that it is a two's complement integer?

2.7.2. For the patterns above, what base 10 number does it represent, assuming that it is an unsigned integer?

2.7.5. For the base ten numbers above, convert to two's complement hexadecimal.

Problem 2

• 1010 1010 0101 0101
• 1111 1111 1111 1111
• 0111 1111 1101 1011
• 0101 0101 0101 0101

Problem 3

• BEEF
• CAFE
• 1EE7
• ABCD

Problem 4

• A nibble using one's compliment.
• A nibble using two's compliment.
• A byte using unsigned numbers
• A byte using sign-magnitude.

Problem 5

  /*
    Name:
    Lab section time:
  */

  #include <stdio.h>

  int majorBit (unsigned int n);

  int main ( )
  {
    printf ("# majority bit in base 2 representation of %u = %d, should be 0\n",
      0, majorBit (0));
    printf ("# majority bit in base 2 representation of %u = %d, should be 1\n",
      1, majorBit (1));
    printf ("# majority bit in base 2 representation of %u = %d, should be 2\n",
      2863311530u, majorBit (2863311530u));
    printf ("# majority bit in base 2 representation of %u = %d, should be 0\n",
      536870912, majorBit (536870912));
    printf ("# majority bit in base 2 representation of %u = %d, should be 1\n",
      4294967295u, majorBit (4294967295u));
    return 0;
  }

  int majorBit (unsigned int n)
  {
    /* your code here */
  }

Problem 6

  # ./majorbit 17
  0
  # ./majorbit 255
  1
  # ./majorbit 10 20
  too many arguments!
  # ./majorbit
  [the same result as from problem 5]

Extra for experts: Implement this exercise without using the library function atoi (or something comparable).