1.2 Memory and Storage

Question 1

Primary Storage

Answer 1

A computer system uses primary storage (also known as main memory) to hold data and programs that are currently being used and processed.

Question 2

Non-volatile Memory

Answer 2

It is permanent memory - it keeps its content even when it has no power.

Question 3

Volatile Memory

Answer 3

It is temporary memory. It requires power to retain its data

Question 4

Random Access Memory (RAM)

Answer 4

Used as the main memory in a computer. It can be read and written to. RAM is volatile.
Purpose: temporary store of currently executing instructions and their data. E.g. applications and the operating system in use.

Question 5

What is stored in RAM?

Answer 5

• Programs currently in use
• Data currently in use
• Operating system currently in use

Question 6

Why might we need additional RAM?

Answer 6

• The current amount of RAM may not meet the requirements of the software we want to run.
• The computer may be running slowly.
• We may want to run more programs at once.
• It may be constantly using virtual memory

Question 7

Read Only Memory (ROM)

Answer 7

Non-volatile memory. Read only.

Purpose: stores instructions for starting the computer called the bootstrap.

Question 8

What are the differences of RAM and ROM?

Answer 8

• ROM is non-volatile and RAM is volatile.
• RAM loses memory when the computer is switched off, ROM doesn’t.
• RAM is easily expandable, ROM size is usually fixed for a given computer.
• Contents of RAM change frequently, contents of ROM hardly ever change

Question 9

Virtual memory

Answer 9

Virtual memory is a section of volatile memory created temporarily on the storage drive. It is created when a computer is running many processes at once and RAM is running low.

Question 10

How does virtual memory work?

Answer 10

Part of the secondary storage used when RAM is full.
Data can be moved from RAM when it is full to the VM so the RAM can be filled with data.
When you need the data, it is transferred back from VM to RAM

Question 11

Why is virtual memory needed?

Answer 11

• When you need to run more applications on the computer than RAM can support. (too many applications or a memory-intensive application)
• More memory can be used than there is in the system

Question 12

Disadvantages of virtually memory

Answer 12

Applications may run slower if the system is using virtual memory.
Likely takes more time to switch between applications.

Question 13

Secondary Storage

Answer 13

• it is not directly accessible by the CPU
• the types of storage are hard disk drive (HDD) and solid state drive (SDD)
• it is non-volatile

Question 14

Common types of secondary storage

Answer 14

• Optical
• Magnetic
• Solid State

Question 15

Optical storage

Answer 15

Use: music, films and archive files.

Low capacity. Slow access speed. High portability. Prone to scratches. Low cost.”