Primary Storage

Question 1

What is primary storage?

Answer 1

Primary Storage consists of ROM and RAM Registers and Cache.

Question 2

What is secondary storage?

Answer 2

Secondary Storage is long-term, non-volatile storage of files and programs.

Question 3

Why is primary AND secondary storage needed?

Answer 3

Primary is needed to store data & instructions that the CPU needs to access. Secondary is needed to store files long-term.

Question 4

What is the purpose of ROM?

Answer 4

ROM is used to store the boot-up sequence or BIOS program that the CPU executes as soon as it turns on. The BIOS contains instruction that load the operating system from secondary storage into RAM for the computer to continue booting up.

Question 5

What is the purpose of RAM?

Answer 5

RAM temporarily stores. (1) Part of the Operating system currently in use by the CPU, (2) Programs currently in use by the CPU (3) Data currently in use by the CPU.

Question 6

Describe two differences between RAM and ROM.

Answer 6

“RAM stores programs and data that are currently in use by the CPU whereas ROM stores boot up instructions for starting up the computer”.

Question 7

Why is Virtual Memory needed?

Answer 7

When RAM is full no more programs can be opened, so VM allows users to have more programs open at once than can fit in RAM.

Question 8

How does Virtual memory work?

Answer 8

When RAM is full (1) parts of programs that are not currently used (1) are moved /transferred from RAM into secondary storage (1) so that RAM has space for a new program to load. Once the original program is needed again it is moved from the secondary storage back into RAM. (1) Using virtual memory allows users to have more programs open at once than can fit in RAM.

Question 9

What are the disadvantages of Virtual memory?

Answer 9

VM is slower to access data than using RAM directly (because data has to be moved back to RAM first).

Question 10

What are the disadvantages of Virtual memory?

Answer 10

Moving data between RAM and VM takes processor time. *must say slower to access data not just “slower” (If this happens excessively and the CPU needs to constantly move programs to and from the hard disk this is called disk thrashing.)