1.2: MEMORY AND STORAGE

Question 1

What is RAM?

Answer 1

Random access memory; which is main memory

Question 2

What is ROM?

Answer 2

Read only memory

Question 3

What is the purpose of Ram?

Answer 3

Stores data and instructions for programs that are currently in use and the operating system

Question 4

How is primary memory obtained? and why is it used?

Answer 4

• Data and instructions are copied into main memory when they are required
• because it would be too slow to access everything directly from the hard disk.

Question 5

What is the purpose of ROM?

Answer 5

It stores data and instructions that are required for the BIOS and embedded systems

Question 6

Define volatile and non-volatile

Answer 6

Volatile- loses all its data and contents when the device is switched off
Non-volatile- keeps all its data and contents even when the device is turned off

Question 7

Can the instructions of RAM and ROM be overwritten?

Answer 7

RAM- yes, the contents of RAM can be changed at any time, simply by overwriting them with other data and/or instructions.

ROM- no, it is read-only memory, the instructions cannot be overwritten once it has been set by the manufacturer

Question 8

3 differences between ROM and RAM

Answer 8

ROM:

• non volatile
• read only
• stores data and instructions for the BIOS/embedded systems

RAM:

• volatile
• can be read and written to
• stores data and instructions for programs that are currently open

Question 9

EQ: An increase in RAM capacity can improve the speed of your computer. Explain why an increase in ROM size would not have the same effect.

Answer 9

-Rom is only required to be as large as the BIOS/ start up instructions inside it,
-therefore any additional space will make no difference.
New files cannot be written into the new space as it is read only

Question 10

Why is primary memory effective? (3)

Answer 10

• built inside the computer.
• can be read from and written to extremely quickly.
• gives processor fast access to data and instructions

Question 11

In what way is primary memory NOT effective?

Answer 11

Primary memory is comparatively limited in size, especially when compared with secondary storage.

Question 12

What is virtual memory?

Answer 12

A section of a computer storage drive/ hard disk which is temporarily used as RAM.

Question 13

What does virtual memory enable to happen and why is it effective?

Answer 13

• enables data in RAM and not currently being used to be transferred to the hard disk.
• frees up room in RAM for other programs and data

Question 14

What happens when data from the hard drive is needed again?

Answer 14

any other unused data is transferred to the hard disk before the original data is SWAPPED back to RAM.

Question 15

why is swapping not very time efficient? + additional reason

Answer 15

• secondary storage devices have slower access times than RAM, therefore the computer’s processing performance can be severely impaired and it will be noticeably slower
• disk thrashing

Question 16

How could you improve processing performance

Answer 16

increasing the size of the RAM, thereby reducing the need for virtual memory.

Question 17

What is cache memory?

Answer 17

-high-speed random access memory (RAM) built into processor.

Question 18

What does cache store?

Answer 18

stores frequently used data and instructions

Question 19

what is the correlation between cache and a computer’s processing speed?

Answer 19

The more cache memory a computer has, the faster it runs.

Question 20

why does cache tend to be expensive? and what assumption can you make from this?

Answer 20

• due to high-speed performance, cache memory is more expensive to build than RAM.
• Therefore, cache memory tends to be very small in size.

Question 21

What is Flash memory?

Answer 21

Flash memory is non-volatile memory than can be read from and written to

Question 22

Characteristics of Flash memory: what is it ideal for?

Answer 22

requires little power and contains no moving parts,

making it an ideal storage medium for many modern devices

Question 23

What can Flash memory also be used as?

Answer 23

external secondary storage, e.g) USB memory sticks and solid-state drives.

Question 24

Explain why secondary storage is needed:

Answer 24

• long term (permanent), non-volatile storage/storing when the device is turned off
• to store data and files

Question 25

Why is secondary storage crucial to a device?

Answer 25

Without secondary storage all programs and data would be lost the moment the device is switched off.

Question 26

Do all devices need secondary storage? Give an example. (3 points)

Answer 26

• No
• embedded systems do not need to store data when the power is turned off.
• the instructions needed to run them are stored in ROM and any user data is held in RAM

Question 27

Additional negative of magnetic SS? and how could this affect the SS?

Answer 27

• They are vulnerable to magnetic fields.

- a strong magnet might possibly erase the data the device holds.

Question 28

What do SSDs use and for what reason?

Answer 28

-use non-volatile random access memory (RAM) to store data indefinitely.

Question 29

What are some major advantages of SSD? (2)

Answer 29

• tends to have much faster access times than other types of devices and,
• because they have no moving parts, are more durable.

Question 30

the 8 units of data storage:

Answer 30

o Bit
o Nibble (4 bits)
o Byte (8 bits)
o Kilobyte 
o Megabyte
o Gigabyte
o Terabyte 
o Petabyte