ECS 15 Introduction to Computers
Instructor: Liu
Name:
Student ID #:
Session #:
Midterm Exam:
Duration: 80 Minutes
1. The exam is closed book. However, you may refer to one sheet of A4
paper (double sided) of your own notes.
2. Try to solve as many as can.
3. Show your reasoning clearly. If your reasoning is correct, but the final
answer is wrong, you will receive most of the credit.
4. Write your solution on this paper. If you need extra paper, use plain white
paper. Write your name on any extra paper.
5. There are six problems in total.
Good Luck!
Question
Points
1
2
Do not write in this box.
3
4
5
6
Total
1. Fill the blanks (2 points each question).
a. A ___________ is used to convert digital values to analog sound.
b. ________ (ASCII/Unicode) covers a larger set of characters.
c. Starting a computer is called _________.
d. IC is short for_____________, which is critical to the development of
microprocessors.
2. True or False (2 points each). Write your answer in front of the question.
a. There is a strict line between operation system software and application
software.
b. It is usually faster to access data stored in memory than that in hard drive.
c. MP3 is a lossless compression scheme.
d. The hexadecimal number 99 is the same as the decimal number 99.
e. Any 2 GHz computer will always run faster than a 1 GHz computer.
f. Digital sound can be recorded, but it cannot be edited.
3. Multiple choices (2 points each).
I. What is a typical size of the memory in a current desktop?
a. 1GB
b. 100MB
c. 100 GB
d. 1000Mb
II. 1GB is exactly
a. 1billion bits
b. 1 billion bytes
c. 2 30 bytes
d. 1 million bits
III. In a modern computer, the Fetch/Execute Cycle operates
a. Once per second
b. thousands of times a second
c. hundreds of thousands of times a second
d. hundreds of millions of times a second
4. Name three popular operating systems.
5. (5 points) convert F3 (hexadecimal) to its decimal and binary format. Please write
down your steps.
Spoiler ..............
1. Fill the blanks (2 points each question).
a. A digital-analog converter (DAC) is used to convert digital values to
analog sound.
b. Unicode covers a larger set of characters.
c. Starting a computer is called booting.
d. IC is short for integrated circuit, which is critical to the development of
microprocessors.
2. True or False (2 points each). Write your answer in front of the question.
e. There is a strict line between operation system software and application
software. F – The software shipped as part of the operating system is
often used by application software, making it difficult to isolate one
part from another.
f. It is usually faster to access data stored in memory than that in hard drive.
T
g. MP3 is a lossless compression scheme. F – MP3 is a lossy compression
scheme.
h. The hexadecimal number 99 is the same as the decimal number 99. F –
The hexadecimal number 99 has decimal value 16^9 + 9 = 153.
i. Any 2 GHz computer will always run faster than a 1 GHz computer. F –
The speed of a computer depends on many factors, such as the
program being run, the instructions used by the program, the size and
speed of the memory, and many more. Clock speed is usually only a
small part of a computer’s perceived speed.
j. Digital sound can be recorded, but it cannot be edited. F – Digital sound
can be edited.
3. Multiple choices (2 points each).
IV. What is a typical size of the memory in a current desktop?
a. 1GB
b. 100MB
c. 100 GB
d. 1000Mb
V. 1GB is exactly
a. 1billion bits
b. 1 billion bytes
c. 2 30 bytes
d. 1 million bits
VI. In a modern computer, the Fetch/Execute Cycle operates
a. Once per second
b. thousands of times a second
c. hundreds of thousands of times a second
d. hundreds of millions of times a second
4. Name three popular operating systems .
Windows, MacOS, Linux, xBSD, Solaris, …
5. (5 points) convert F3 (hexadecimal) to its decimal and binary format. Please write
down your steps. (this question is on the hard side.)
F3(Hex)= 15*16 +3 = 243 (decimal)
F =1111
3=0011
F3 (Hex)= 11110011 (binary)