1.1.3 (Input, Output, and Storage)

Question 1

What is an input device, and give an example?

Answer 1

• Any hardware giving information to the computer
• Keyboard, mouse, webcam, mic

Question 2

What is an output device, and give an example?

Answer 2

• Any hardware giving information to the user
• Monitor, speakers

Question 3

Why is secondary storage needed on a computer system?

Answer 3

To store files including when the computer is turned off

Question 4

What are the characteristics of Magnetic Disk Storage e.g. HDD?

Answer 4

• Large capacity
• relatively cheap
• sensitive to movement due to moving parts

Question 5

What are the characteristics of Solid State (flash) storage?

Answer 5

• Lower capacity
• relatively expensive
• no moving parts so not sensitive to movement

Question 6

What are the characteristics of Optical Disc storage?

Answer 6

• Low capacity
• very cheap per disc
• moving parts so can’t be moved while running

Question 7

List the 6 characteristics of secondary storage

Answer 7

Cost Capacity Reliability Speed Portability Durability (Computers Can Really Store Petabytes of Data)

Question 8

What are the three types of secondary storage?

Answer 8

• Magnetic Disk
• Optical Disk
• Solid State

Question 9

What is primary memory?

Answer 9

Memory directly accessed by the CPU

Question 10

What are the two types of primary memory?

Answer 10

RAM and ROM

Question 11

What is the purpose of ROM?

Answer 11

• Stores BIOS
• Stores boot up instructions
• Stores data that should not be changed

Question 12

Is ROM volatile or non volatile?

Answer 12

Non volatile

Question 13

What is the purpose of RAM?

Answer 13

Stores currently running programs and data

Question 14

Is RAM volatile or non volatile?

Answer 14

Volatile

Question 15

Why do computers need virtual memory?

Answer 15

• When RAM is full
• secondary storage is used as temporary RAM

Question 16

How does virtual memory work?

Answer 16

• When RAM is full data from RAM is moved to secondary storage to make space
• RAM can then be filled with new data
• When data in virtual memory is needed it is moved back to RAM

Question 17

How do magnetic disks work?

Answer 17

• Metal disks are coated with magnetic material
• This can be positively or negatively charged
• The disks are rotated and an arm moves to the desired location to read a charge
• +VE charge (1), or a -VE charge (0)

Question 18

How does optical storage work?

Answer 18

• Pits and lands are burned into a disk
• The disk is spun to find the desired memory location
• Light is shone onto the disk
• If it is reflected by a land, it’s a 0
• If not, it’s a 1

Question 19

How does solid state work?

Answer 19

• Electrons are pushed through a gate with an electric charge
• A 1 is recorded if there are any electrons through the barrier
• Each cell is checked for a 1 or a 0