3_4_4 Systems architecture

You should be able to:

  • Explain the Von Neumann architecture.
  • Explain the role and operation of main memory and the following major components of a central processing unit (CPU):

•• arithmetic logic unit

•• control unit

•• clock

•• bus

  • Explain the effect of the following on the performance of the CPU:

•• clock speed

•• number of processor cores

•• cache size

•• cache type.

  • Understand and explain the Fetch-Execute cycle.
  • Understand the differences between main memory and secondary storage.
  • Understand the differences between RAM and ROM.
  • Understand why secondary storage is required.
  • Be aware of different types of secondary storage (solid state, optical and magnetic).
  • Explain the operation of solid state, optical and magnetic storage.
  • Discuss the advantages and disadvantages of solid state, optical and magnetic storage.
  • Explain the term 'cloud storage'.
  • Explain the advantages and disadvantages of cloud storage when compared to local storage.
  • Understand the term 'embedded system' and explain how an embedded system differs from a non-embedded system.

REVISE:

Find out more about storage here: http://www.bbc.co.uk/education/guides/zxgkxnb/revision/6

Cloud storage: This is just the same devices used for storage (magnetic, ssd etc.) but it is kept on a server farm in a separate location to the user called a remote location. The servers could be anywhere in the world and are connected via a network, usually the Internet. Server farms usually have a fail safe (a back up for the back up). This is where an exact replica of the files are kept in a separate location in case of natural disaster or other threats. This is particularly important for crucial data like banking and stock markets.

TEST:

  1. Download and print the test paper here: https://drive.google.com/open?id=0B5fLtQ0Xgr2PbHA3QUNfVXYyWU0
  2. Try the mock test yourself.
  3. Use the 3.4.4 Walking Talking Mock below to guide you through answering the questions.

SOURCE RECOGNITION - PLEASE NOTE: The examination examples used in these walking talking mocks are samples from AQA from their non-confidential section of the public site. They also contain questions designed by TeachIT for AQA as part of the publicly available lesson materials.