Chapter 2 - Computer Hardware

Question 1

What are the two components of the CPU?

Answer 1

• arithmetic and logic unit carries out all of the arithmetic and logic calculations
• control unit uses electrical signals to control the flow of data within the CPU

Question 2

What is the function of the CPU?

Answer 2

1. Fetch the instructions stored in memory
2. Decode the instruction to find out what processing to do
3. Execute the instruction

Question 3

How do you increase the performance of a CPU?

Answer 3

Increase the clock speed, cache size and number of cores.

Question 4

What is clock speed?

Answer 4

Number of cycles of the fetch execute cycle completed in one second, determined by an electronic clock chip, measure in Gigahertz GHz.

Question 5

What is multiple processor core?

Answer 5

More than one CPU working together to process more data simultaneously.

Question 6

What is hardware?

Answer 6

Physical components of a computer system, anything that can be seen or touched.

Question 7

What is a disadvantage of a multiple processor core?

Answer 7

More complicated operating systems are needed to manage them.

Question 8

What is RAM?

Answer 8

Random access memory which is volatile (data is lost when power is turned off)

Question 9

What is ROM?

Answer 9

Read only memory which is non volatile

Question 10

When can the computer access and change RAM + ROM

Answer 10

It can access RAM any time

It can never access ROM (programmed during manufacture

Question 11

What does RAM + ROM store?

Answer 11

RAM: Programs and data being used by the computer
ROM: instructions and data required to start up the computer (boot sequence + boot loader)

Question 12

What does RAM + ROM contain?

Answer 12

Ram: operating system
Rom: boot program

Question 13

Is Ram + ROM large or small?

Answer 13

Ram: Large 4GB+
Rom: smal 1/2MB

Question 14

What is the purpose of a CPU?

Answer 14

It carries out all the processing in a computer.

Question 15

What is virtual memory?

Answer 15

It I part of the hard rice an is used as an extension to RAM.

Question 16

What is cache memory?

Answer 16

Very expensive memory which has access times similar to CPU (fast)

Question 17

Why is there a need for cache memory?

Answer 17

The CPU cannot access main memory at the same speed as re processor clock chip - transferring data from main memory (RAM) to the CPU causes delays. Data that is in use is transferred to cache memory to make access to it faster.

Question 18

How does the CPU interact with cache memory?

Answer 18

CPU check cache to see if data needed is there a it requests data
If data is not in cache, CPU requests data from RAM
Data requested from main memory is copied to cache
Data is sent to CPU

Question 19

How does RAM affect the performance of a computer?

Answer 19

Adding RAM reduces the use of virtual memory and improves the performance of a computer.
This is because data is passed between RAM and virtual memory and access to virtual memory is slower.

Question 20

When is virtual memory used?

Answer 20

When the computer does not have enough RAM to hold all the data and programs required.

Question 21

Why is data represented in binary form in computers?

Answer 21

Because it is easy to tell the state of the switch on (0) or off (1).

Question 22

What is flash memory?

Answer 22

A type of ROM which can be rewritten, it is used as a portable medium for toeing and transferring data.

Question 23

Why is there a need for secondary storage?

Answer 23

Because secondary storage is non volatile and there is a need to store data and programs when the power is switched off.

Question 24

What are three examples of secondary storage and what are they?

Answer 24

Magnetic hard disk: store operating system, installed programs and data
Optical disk: excellent for transferring files or distributing software
Flash memory/solid state: consumes little power

Question 25

What 5 things should be considered when choosing secondary storage?

Answer 25

Capacity, speed, portability, durability and reliability

Question 26

Which is most expensive of all secondary storage?

Answer 26

Flash memory
Magnetic hard drive
Optical disk

Question 27

Why is there a need for input and output devices?

Answer 27

Computers process data we supply as inputs to provide us with required outputs, if a computer cannot accept inputs an provide outputs then it is of little value

Question 28

Examples of input devices?

Answer 28

Keyboard ( used for data entry)
Mouse (controls a pointer on the screen)
Touch screen (allows user to interact directly with icons to control the device)
Microphone
Camera
Bar code scanner (reads light which is reflected back to identify a product)

Question 29

Examples of output devices?

Answer 29

Monitor (displays text, image, video)
Printer ( produce shard copy on paper)
Speaker (produces sound)
Actuator (creates physical movements in response to computer commands)

Question 30

Example of input device for people with specific needs?

Answer 30

Eye-typed : camera tracks movement of user’s eye and detects which key user is looking at + slow blinks are used to select the key to type commands into the computer system
Braille keyboard: keys have embossed patterns
Puff suck switch: used by blowing or sucking uni a tube
Foot mouse : track ball device operated by the foot

Question 31

Which secondary storage has the larger capacity?

Answer 31

Magnetic hard drive
Optical disk
Flash memory