1.2

• What is memory?

  where data is stored for quick access
• How is secondary storage accessed?

  main memory can be accessed directly CPU whereas secondary storage cannot. data and instructions first have to be read from storage into memory
• what is secondary storage?

  where saved files and programs are stored on a more permanent basis, without this all data would be lost when power is turned off
• what does RAM stand for?

  random access memory
• what does ROM stand for?

  read only memory
• what does RAM do?

  stores user data/programs/part of operating system which is currently in use. acts as temporary storage for programs and data while the program is being executed
• how does RAM work

  when a program is to be executed it has to be loaded from the hard disk into main memory so that the processor can access the instructions. any data needed for the program to run is also loaded into main memory
• what does ROM do?

  stores the BIOS/bootstrap leader which is required at start up of the computer
• bootstrap leader

  this is a small program that loads the operating system. once the operating system is loaded it take care of the rest
• is RAM volatile or non-volatile?

  volatile
• is ROM volatile or non-volatile?

  non-volatile
• what does increasing the amount of RAM do

  increases the amount of storage on the computer system therefore increases the speed (won't need virtual memory as this will make the computer more slow)
• define volatile?

  data is lost when the power is turned off(temporary memory)
• define non-volatile

  data is not lost when the power is turn off(permanent memory)
• why is it important ROM is non volatile

  the data is not lost when the power is turned off making it permanent memory. This is important so if you accidently turn the power off you won't lose your data (boot up instructions)
• what does ROM mean

  read only memory, you cannot write over the contents once it has been created
• what can memory do in RAM?

  memory can be written to or read from
• what can memory do in ROM?


  memory can only be read from but not written to
• why does volatile do?

  stores data that is being used at the present
• what does non-volatile memory do?

  used to store start up instructions and driven
• what does volatile memory do for RAM?

  loads software into the RAM so that it can be used
• why is ROM needed?

  computer can't turn on without it
• what can RAM do?


  can be upgraded
• why does RAM need secondary storage

  ram is volatile so when you turn off you computer it loses it content when you turn you have to get the basic start-up routine from somewhere that is not volatile. the operating system and all your programs will be stored on the secondary storage but need to be loaded into ram
• what does increasing the RAM do

  increases the amount of storage on the computer system therefore increases the speed (won't need virtual memory as this will make the computer more slow)
• what does virtual memory do?


  allow a computer to compensate for physical memory shortages by temporarily transferring data from random access memory (RAM) to disk storage. stops the computer crashing and access more space but the cpu can't access it
• what are the benefits of virtual memory?

  freeing applications from having to manage a shared memory space, increased security due to memory isolation, and being able to conceptually use more memory than might be physically available
• where is ROM found?

  motherboard
• where is RAM found?

  on a printed card that is slotted into the motherboard
• where is cache memory found?

  found on the cpu chip
• what is cache memory?


  high speed memory attached to the cpu
• what does the cpu do?


  places instruction that are used the most frequently in the cache so that the cpu can access the data quicker and speed up the running of tasks
• what is level one of cache?

  extremely fast but relatively small.embedded in processor chip. closest to the processor. 8kb-64kb
• what is level two of cache?


  larger than level one but further from the core
• what is level three of cache?


  memory is used to improve the performance of level one and level two.double the speed of RAM
• why is secondary storage needed?


  To store data and programs when the power is switched off
• differences between secondary storage and main memory

  it is non-volatile, it generally holds much more data than main memory and is relatively expensive per MB. secondary storage technologies tend to have slower speeds than main memory
• features when choosing a storage device

  capacity, speed, portability, durability, reliability
• what are external storage used for?


  back up data

  share files over a network

  add more storage space

  transfer files between computers
• what are internal storage devices used for?


  stores data on a permanent devices