CS32 : Who switched the lights off?


When the lights go out and your computer screen goes black, what happens to all the data that was flowing around the little wires? This section focuses on the operation of the main types of secondary storage media.

We are learning ...
  • About secondary storage devices
So that we can ...
  • Describe the principles of operation of a magnetic storage device
  • Describe the principles of operation of an optical storage device
  • Describe the principles of operation of solid state storage
  • Virtual storage (
  • Access the suitability of different storage devices for different situations

Within a computer system, main memory or the Immediate Access Store (IAS) / Primary Storage is used to store programs and data that the computer is currently using. This gives the computer fast access to read and write data whilst it is operating but the IAS is volatile - it's contents will be lost when the computer is switched off. 

Activity 1 Secondary storage devices


Secondary storage devices are non-volatile - they retain their data when the power is removed. The most important / common secondary storage devices are ...
  • Magnetic storage (hard drives)
  • Optical storage (CD-ROM / CD-R / CD-RW // DVD-ROM / DVD-R / DVD-RW // Bluray)
  • Solid state storage (SSD drives)


Task 1.1
 Too right I am!

Research each of the storage devices named in the list above and produce a simple Infographic to illustrate what you have discovered. Make sure that you reference all the sources you have used in your research as well. If you need any inspiration, visit this Google search page for Infographics.


You can use the course textbook to help you if you like but make sure that you include the following in each of your infographics. Pay particular attention to the methods of operation, especially for the optical disks as they all work differently  ...
  • Principles of operations (how does it work?)
  • Primary uses (what's it mainly used for?)
  • Typical capacity (how much can it hold?)
  • Advantages and disadvantages (good and bad bits)
  • Lifetime (how long will the data last)
Consider sharing the workload amongst the rest of your peers - a problem shared is a problem halved!

OUTCOME : A set of Infographics outlining the operation of various secondary storage devices.



Task 1.2
 Storage devices compared

Download the resources Storage Devices Compared.docx from the lessons resources, complete and submit to your teacher for assessment.

OUTCOME : Completed worksheet



Activity 2 Virtual (cloud) storage

NEW SECTION

Extension Activities 

How about these?
  • Watch this video on Hard Drive operation from the Engineer Guy


  • Watch this video comparing hard drive operation and SSD drive operation


  • How do CD-R disks work @ How Stuff Works

What's next?

Before you hand your book in for checking, make sure you have completed all the work required and that your book is tidy and organised. Your book will be checked to make sure it is complete and you will be given a spicy grade for effort.

END OF TOPIC ASSESSMENT