CSCI 312, Spring 2005, Test 1

Please answer carefully and thoughtfully.
Please write neatly. If I can not read it, I will count it wrong.
Use as much paper as you wish, but label each of your questions, and put your name on each page.

(2 points) You wish to encode (represent in binary) an instruction set containing 45 instructions with a minimal number of bits. How many bits will be required?
(2 points) Given 5 bits, how many things can you label with a unique bit pattern?
(4 points) Draw a diagram of the von Neumann Architecture. Label each part.
(6 points) Draw a diagram of each of the following, explain how they differ from the van Neumann model.
1. SIMD
2. MIMD
(6 points) Name and describe the technology in each of the generations of computing. (You should use the generations described by our author)
(3 points) A computer runs at 500MHz, with A CPI of 4. How long does it take to execute an instruction? Show all work and express the answer in the correct units.
(3 points) A clock has a period of 0.5ns, what the clock speed? (Express your answer in the correct units, and show all work)
(4 points) How are a transistor and a vacuum tube similar? How are the different.
(6 points)
1. Express -4 and 6 in 5 bit sign magnitude
2. Express -4 and 6 in 5 bit two's compliment
3. Express -4 and 6 in 5 bit excess 15
(4 points) Explain how two's compliment is more appropriate for representing signed integers in a digital computer. Give specific examples. (I will assume you were in class on Wednesday).
(4 points) Represent the following in binary. (Show all work)
- .6875
- .6
(10 points) Describe the IEEE 754 single precision format. Discuss denormals, infinity and NAN. Show how to represent each.
(4 points) Define precision, gap, overflow and underflow
(12 points) Using a 16 bit system which mimics the IEEE 754 format, but has 5 bits for the exponent, represent each of the following numbers.
1. 0
2. .0625
3. .6875
4. 257
5. 2^-18+2^-21
6. 2²⁰⁰⁰