CS ECE 252 INTRODUCTION TO COMPUTER ENGINEERING COMPUTER SCIENCES DEPARTMENT UNIVERSITY OF WISCONSIN MADISON Prof Mark D Hill Prof Mikko Lipasti TAs Sanghamitra Roy Eric Hill Samuel Javner Natalie Enright Jerger Guoliang Jin Midterm Examination 1 In Class 50 minutes Monday October 1 2007 Weight 15 CLOSED BOOK NOTE CALCULATOR PHONE COMPUTER The exam has four two sided pages Plan your time carefully since some problems are longer than others NAME SECTION ID 1 Problem Number Maximum Points 1 4 2 3 4 5 6 3 3 4 4 4 7 4 8 4 Total 30 Actual Points 2 Problem 1 4 points a What is the largest most positive integer that can be represented as an unsigned integer using 13 bits b What is the largest most positive integer that can be represented as a two s complement integer using 13 bits Problem 2 3 points Consider bitwise logical operations Compute 1101 AND 0111 OR NOT 0011 3 Problem 3 3 points Convert the number 84 base ten into two s complement representation with 8 bits Problem 4 4 points Consider the 8 bit binary bit pattern 10010010 What is its decimal base ten value if the bit pattern is interpreted as a An unsigned integer b A two s complement integer 4 Problem 5 4 points a Add the following 5 bit two s complement binary numbers 01111 01101 Express your answer in 5 bit two s complement Please indicate if there was an overflow b Add the following 5 bit two s complement binary numbers 11110 01111 Express your answer in 5 bit two s complement Please indicate if there was an overflow Problem 6 4 points a Convert the ASCII string F4n into binary See attached ASCII table Only convert the characters between the quotation marks b Convert the binary value 0010010001101011 into an ASCII string 5 Problem 7 4 points a What is the base ten decimal value represented by binary 110 101 b The bits for an IEEE floating point number are allocated as follows sign 1 bit exponent 8 bits fraction 23 bits S exponent 127 where N 1 x 1 fraction x 2 Convert 1 10000001 11000000000000000000000 to decimal Problem 8 Circle the correct answer 2 points each I Which of the following is a universal computing device a A 16 button 0 9 period x calculator b A laptop computer running Windows XP c An ultrafast supercomputer d All of the above e Both b and c II When referring to an algorithm definiteness means a Each step must be precisely defined b The algorithm s variables must not overflow a fixed number of bits c The number of unknowns and equations is the same d None of the above 6 ASCII Table Character nul soh stx etx eot enq ack bel bs ht lf vt ff cr so si dle dc1 dc2 dc3 dc4 nak syn etb can em sub esc fs gs rs us Hex 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F Character sp 0 1 2 3 4 5 6 7 8 9 Hex 20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 31 32 33 34 35 36 37 38 39 3A 3B 3C 3D 3E 3F Character A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Hex 40 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D 4E 4F 50 51 52 53 54 55 56 57 58 59 5A 5B 5C 5D 5E 5F Character a b c d e f g h i j k l m n o p q r s t u v w x y z del Hex 60 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E 6F 70 71 72 73 74 75 76 77 78 79 7A 7B 7C 7D 7E 7F 7 Scratch Sheet in case you need additional space for some of your answers 8