Memory

Question 1

What is computer memory often called? (2 things)

Answer 1

Main memory or primary storage

Question 2

What forms does computer memory come in? (4 forms)

Answer 2

Random Access Memory (RAM)
Read only Memory (ROM)
Virtual memory
Flash memory

Question 3

How can main memory be directly accessed?

Answer 3

By the CPU

Question 4

What is RAM?

Answer 4

Random Access Memory

Question 5

What is ROM?

Answer 5

Read Only Memory

Question 6

Where are software programmes stored long term?

Answer 6

On the hard disk

Question 7

The CPU can’t access a programme directly from the hard disk. How is it loaded and where?

Answer 7

It needs to be loaded by the operating system into RAM

Question 8

Why do we call Ram Random Access Memory?

Answer 8

Because the CPU can access any memory location, at any time, in any order.
This makes programmes held in RAM able to run very quickly

Question 9

The CPU can access any memory location, at any time, in any order. What does that mean for programs held in RAM?

Answer 9

It means that programmes held in RAM can run very quickly

Question 10

What is RAM measured in?

Answer 10

Gigabytes (GB)

Question 11

What would a typical PC have as RAM and what might it go up to for people using heavy applications?

Answer 11

4GB of RAM for a typical PC and up to 64GB of RAM for heavy application users

Question 12

Why do we call RAM volatile and ROM non-volatile

Answer 12

Because RAM needs constant electrical power, if power is lost, everything stored in RAM will be lost, whereas ROM is non-volatile so it doesn’t require power to store the information inside it

Question 13

What type of memory loses its data once power to the memory chip is broken?

Answer 13

Volatile memory

Question 14

When RAM fills to capacity, how does the operating system create virtual memory?

Answer 14

The OS can mark sections of the hard disk to use as virtual memory

Question 15

Why is virtual memory classified as ‘main memory’?

Answer 15

Because it can be accessed by the CPU

Question 16

What does the operating system do with data and programmes that are in RAM but are not currently being used?

Answer 16

Moves the data and programmes into virtual memory

Question 17

What does the operating system do with data and programmes that are in RAM but are currently being used?

Answer 17

Nothing, they remain in RAM

Question 18

What is disk thrashing?

Answer 18

The constant switching between RAM and virtual memory can lead to a high rate of hard disk access - you can hear the hard disk working when it is being thrashed

Question 19

What happens to the computers performance when the virtual memory is being heavily used?

Answer 19

It slows down

Question 20

what two things are characteristics of ROM

Answer 20

Its contents cannot be overwritten / changed

It is non volatile - it keeps data even if there is a power cut

Question 21

Until recently, ROM was used to store computer boot up instructions (BIOS). Where is BIOS stored nowadays?

Answer 21

In the flash memory

Question 22

What is ROM still used for?

Answer 22

ROM is still used to store the MAC address on a network card

Question 23

When you switch on your computer, what does BIOS do?

Answer 23

The BIOS checks the hardware is installed correctly (e.g. memory, graphics card)

Question 24

What three things does the BIOS do when the computer is switched on?

Answer 24

1) Check the hardward is properly installed
2) Check the input/output devices
3) It loads the operating system

Question 25

Flash is a non-volatile memory, however, unlike ROM, Flash memory can be used to both read and write data.
What else is often stored on flash?

Answer 25

It is often used to store the BIOS (so that changes to the instructions can be made when needed)