Chapter 9

Question 1

A machine instruction uses how many bytes of memory?

Answer 1

4

Question 2

Converting code that a programmer writes into assembly code is called

Answer 2

Compiling

Question 3

What has made computers faster?

Answer 3

Making everything smaller

Question 4

Which of the following is used for input and output?

Answer 4

Hard disk

Question 5

The processor has how many moving parts?

Answer 5

0

Question 6

From smallest to largest, the correct order of prefixes is

Answer 6

kilo, mega, giga, tera

Question 7

Modern computers know

Answer 7

about a hundred instructions

Question 8

Rerunning a program with the same data produces

Answer 8

exactly the same result everytime

Question 9

If this.Opacity += 1.0; increases the opacity, what line of code would decrease the opacity?

Answer 9

this.Opacity –= 1.0;

Question 10

Which of the following characteristics of a computer depends on the number of Fetch/Execute Cycles it performs per second?

Answer 10

Speed

Question 11

______ deterministically execute instructions to process information.

Answer 11

Computers

Question 12

Without the _____ , the processor is not capable of doing anything interesting.

Answer 12

Operating Systems

Question 13

_____ is an acronym for the name of the location where computer programs run and data is stored.

Answer 13

RAM

Question 14

The _____ part of the computer is the hardware part of the Fetch/Execute Cycle.

Answer 14

Control Unit

Question 15

In addition to fetching instructions, the F/E cycle also fetches

Answer 15

Hardware

Question 16

The math on the computer is done by the

Answer 16

ALU

Question 17

The ____ encodes keystrokes into binary form for the computer

Answer 17

Keyboard

Question 18

The computer’s clock speed is measured in ______.

Answer 18

Hertz

Question 19

Every memory location has a(n)

Answer 19

Address

Question 20

The _____ keeps track of the next instruction to execute.

Answer 20

Program Counter

Question 21

____ is a long list of words, more accurately, a long series of 0’s and 1’s that make up a computer program.

Answer 21

binary object file

Question 22

A ____ is required for every peripheral connected to your computer.

Answer 22

driver

Question 23

_____ is a program that extends the operations a computer can perform beyond the hardwired machine instructions.

Answer 23

operating system

Question 24

What is the speed of the processor on your personal computer? Explain where you found this information.

Answer 24

Settings —> about this PC/Computer

Question 25

How many bits in a kilobyte? Megabyte? Terabyte? (Express as decimal numbers and as powers of 2.)

Answer 25

Kilobyte: 2^10 =1024 bytes 1024 x 8 = 8192 bits
Megabyte: 2^20 = 1,048,576 bytes 1,048,576 x 8 = 8,388,608 bits
Terabyte: 2^40 = 1.0995116e+12 bytes 1.0995116e+12 *8 = 8.7960928e+12 bytes

Question 26

Explain what an “idle loop” is in your own words. When does a computer start this kind of loop?

Answer 26

An idle loop is a background system thread, which the scheduler executes when no other threads are ready to run.
When a computer finishes its work, it enters an idle loop, just checking to see if there are any external inputs.

Question 27

Where does the Fetch part of the cycle get its instructions from? How does it know exactly where to go? Explain your answer in detail.

Answer 27

The Program Counter starts at OOOO. This means that the first address in RAM where the computer will look for instruction is at 0000.

The computer needs somewhere to store the current address in RAM that it is looking for. This is what the Memory Address Register (MAR) is for. 0000 is therefore copied into the MAR. A signal is now sent down through the Address bus to the RAM. The Control Unit sends out a memory read signal, and the contents of the address 0000 are copied through the data bus to the Memory Data Register.

As the data fetched during the fetch stage is an instruction, it is copied into the Instruction Register (IR).As the first instruction has been fetched, the system is at the end of the Fetch stage of the cycle. The program counter can be incremented by 1, so the system is ready to read the next instruction when the next Fetch cycle starts.

Question 28

Computers cannot read high-level programming languages. Explain how a programmer can be understood by a computer.

Answer 28

The computer doesn’t actually learn the language; instead, it parses the language and does what the lines of code tell it to do.

Question 29

Explain the following instruction: ADD 3000, 1050, 1900.

Answer 29

It means to add the value in memory word 1050 to the value of the memory word 1900 and store the result in memory word 3000.

Question 30

List the five steps in the Fetch/Execute cycle, and describe each. Explain how these steps correspond to eating at a restaurant.

Answer 30

1. Instruction Fetch (IF) - Getting the instruction
2. Instruction Decode (ID) - Figuring out what to do
3. Data Fetch (DF) - Gathering the data needed to do it
4. Instruction Execution (EX) - Doing it
5. Result Return (RR) - Save Result
   At a restaurant you get the menu (IF), then figure out what you want to order (ID), formulate in your head your order to relay to the wait staff (DF), give your order (EX), and receive your order (RR).

Question 31

A megabyte is 1,048,576 bytes. Explain why it is not 1,000,000.

Answer 31

Every byte must have an address; one million addresses require 20 bits, but 220 totals 1,048,576, so extra bytes are included to match the number of addresses

Question 32

List 10 devices that can be connected to a computer, and classify each as “input”, “output”, or “I/O”.

Answer 32

Mouse - I
Joystick - I
Keyboard - I
Touchpad - I
Microphone - I
Printer - O
Projector - O
Speaker - O
Headphone - O
Monitor - O