Exercises

1.  Hints and Answers    In what ways are hardware and software different? In what ways are they the same?

2. 1. How many milliseconds (ms) are in 1 second?

   2. How many microseconds (µs) are in 1 second?

   3. How many nanoseconds (ns) are in 1 millisecond?

   4. How many microseconds are in 1 millisecond?

   5. How many nanoseconds are in 1 microsecond?

   6. How many kilobytes (KB) are in 1 gigabyte (GB)?

   7. How many kilobytes are in 1 megabyte (MB)?

   8. How many megabytes are in 1 gigabyte (GB)?

   9. How many bytes are in 20 megabytes?

   10. How many kilobytes are in 2 gigabytes?

3.  Hints and Answers    By what order of magnitude is something that runs in nanoseconds faster than something that runs in milliseconds?

4. Pretend you are ready to buy a new computer for personal use. First, take a look at ads from various magazines and newspapers and list terms you don't quite understand. Look these terms up and give a brief written explanation. Decide what factors are important in your decision as to which computer to buy and list them. After you select the system you would like to buy, identify which terms refer to hardware and which refer to software.

5. Pick your favorite computer language and write a small program. After compiling the program, see if you can determine the ratio of source code instructions to the machine language instructions generated by the compiler. If you add one line of source code, how does that affect the machine language program? Try adding different source code instructions, such as an add and then a multiply. How does the size of the machine code file change with the different instructions? Comment on the result.

6. Respond to the comment mentioned in Section 1.5: If invented today, what name do you think would be given to the computer? Give at least one good reason for your answer.

7.  Hints and Answers    Suppose a transistor on an integrated circuit chip were 2 microns in size. According to Moore's Law, how large would that transistor be in 2 years? How is Moore's law relevant to programmers?

8. What circumstances helped the IBM PC become so successful?

9. List five applications of personal computers. Is there a limit to the applications of computers? Do you envision any radically different and exciting applications in the near future? If so, what?

10. Under the von Neumann architecture, a program and its data are both stored in memory. It is therefore possible for a program, thinking a memory location holds a piece of data when it actually holds a program instruction, to accidentally (or on purpose) modify itself. What implications does this present to you as a programmer?

11. Read a popular local newspaper and search through the job openings. (You can also check some of the more popular online career sites.) Which jobs require specific hardware knowledge? Which jobs imply knowledge of computer hardware? Is there any correlation between the required hardware knowledge and the company or its location?