MODD / Mr. Hansen 12/1/2005

Name: _________________________

Test on Unit 0x60 (Topics 0x61-0x6F, omitting 0x63 and 0x6A)

Time limit: 32 minutes (48 minutes for extended time). A calculator and textbook are permitted.
Each question is worth 6 points.

Instructions: For multiple choice questions, write the capital letter of the best choice in the blank provided. For fill-in questions, write the word or phrase that best fits in the space provided. For free-response questions, write a coherent, legible response in the space provided, or on the reverse if you need more room. Most free-response questions can generally be answered in a few lines.

1, 2.	Many so-called “division by zero” errors that are reported when a computer program runs may actually be ______________________ errors, caused when the absolute value of a divisor (as a result of a previous calculation, or roundoff or truncation error), is less than the _____________________________ .
3, 4.	In integer arithmetic, overflow is easily detected when a sum of two positive numbers produces a number that is _____________ in two’s complement, or when the sum of two negative numbers produces a number that is _____________ in two’s complement.
5.	Compute the one’s complement of the longint 0x3C405B28. No work is required. Give answer in hex.
6.	Compute the two’s complement of the longint 0x3C405B28. No work is required. Give answer in hex.
7.	In one-byte integer arithmetic using two’s complement rules, what does the hex answer BC mean if we obtain it as the final answer to a problem? Convert your answer to decimal.
8.	What is a register?
9, 10.	If the binary value 00110011 is ____________________ left to produce the binary number 01100110, that is equivalent to multiplying by _________ .
11, 12.	Perform the operation 0453 – 1788 (in decimal) using 10’s complement arithmetic. Show your work, including how the final answer should be interpreted (sign and value).
13, 14.	Perform the operation 428A – 12CB (in hex) using 2’s complement arithmetic. Show your work, including how the final answer should be interpreted. It is not necessary to convert to decimal for your final answer; simply state whether the final answer is positive or negative, and how you can tell.
15.	Convert the decimal value 0.5 to IEEE 754 single-precision format. You may ask for some assistance if you get stuck. Give final answer in hex.
16.	State (in hex) how the IEEE754 floating-point value 0xA2874321 would be stored
	(a) on a Mac or most Unix machines
	(b) on a PC (Intel architecture)
17.	Explain briefly what is meant by rounding error and truncation error, and how it is possible for these types of errors to cascade.