1.2.1 primary storage (memory)

Question 1

why do we need primary storage?

Answer 1

primary storage is needed to hold the data and instructions required by the CPU while the computer is running. the CPU can access data quicker from primary storage than from secondary storage

Question 2

what does primary storage consist of?

Answer 2

primary storage consists of:
RAM (random access memory)
ROM (read only memory)

Question 3

RAM characteristics

Answer 3

volatile (contents lost when the power is turned off
read and write
temporary memory
holds the operating system, data and programs while the computer is running
larger than ROM
can be increased
closer to the processor, therefore faster read/write access

Question 4

ROM characteristics

Answer 4

non-volatile (contents remain when the power is turned off)
read only
cannot be increased
bootstrap (holds computers first instructions)
BIOS (basic input/output system)
firmware
smaller than RAM

Question 5

what is virtual memory?

Answer 5

virtual memory is needed to store data when there isn’t enough RAM to store open programs
located on the hard disk (so its secondary)
temporary sotrage - its volatile

Swapping between RAM and virtual memory occurs when programs are not being executed
programs are transferred back in to RAM when needed

Question 6

problems with virtual memory

Answer 6

Slows down the machine because its constantly swapping between programs
constant swapping can cause something called disk thrashing