CS17 : Keeping things ticking over

Without an operating system, your computer would never get past the black screen that tells you who made the motherboard and how much memory you have. Not a lot of use really.

We are learning ...
  • Describe the various roles that operating systems perform
  • Describe the role of the Virtual Machine
  • Describe the operations of the operating system
So that we can ...
  • Describe the role of the operating system in managing resources
  • State what types of operating system there are
    - Distributed
    - Embedded
    - Batch processing
    - Real time (control / transaction)
    - Single user / multi user
    - Multi tasking / multiprogramming
  • Describe the concept of a Virtual Machine
  • Describe other operating system functions
    - Memory management (paging, segmentation, virtual memory, partitioning)
    - Hardware management (BIOS, device drivers, buffers)
    - File management
    - Provision of a user interface
    - Interrupts (Interrupt Service Routines, conditions leading to interrupts, priorities)
    - Scheduling (round robin, first come first served, multi-level feedback queues, shortest job first, shortest remaining time)
    - Processes (running, ready, blocked)
    - Time slicing, polling, threading

Activity 1 Operating systems through the ages (45)

There haven't always been software operating systems. In the old days (around the 1950s), computers were purely electrical machines which were given instructions on punch cards or tape. Machine settings were controlled by a bank of physical switches.

Since then, there have been literally hundreds of operating systems in existence (593 different operating systems and 613 linux distributions if this list is accurate). To document a complete history would be like writing a very long and complicated (and probably quite boring) book.

How many of these logos do you recognise?

Task 1.1 Operating system timeline
Web browser

Try as I might, I cannot find a suitably simple timeline which charts the development of all 593 major operating systems (not surprising really). However, the following websites are interesting ...

History of the operating system at Wikipedia
The Operating System Documentation Project
Timeline of Operating Systems

During your visits to the websites choose one operating system that you haven't heard of before and document it's history.  

OUTCOME : A simple timeline that you have created either on the computer or on paper outlining the development of one operating system. You might also have picked up some general notion of where modern operating systems developed from.

Now you know a little more, watch the video (if you can find a better one, let me know - I'm sat over there ...)

History of operating systems (6:47)


Activity 2 Types of operating system (30)

The operating systems we sit in front of all day are examples of multitasking, single user operating systems. That's not the end (or start) of the story. There are many others ...
  • Batch
  • Real time
  • Single user / Multi user (A Level Only)
  • Multi tasking / Multi programming (A Level Only)
  • Distributed
  • Parallel
  • Embedded
The following video explains quite nicely what the differences between (most) of them are. Keep watching up until just over 4 minutes but don't watch the 'shameless plug' for lynda.com (unless you want to).

Types of operating system as fast as possible (5:42)

Task 2.1 Research into different operating systems
Web browser

You've watched the video, now use your favourite search engine to research these types of operating systems. Try to find 3 you have never heard of before.

In your notebooks : Create a table containing the type, description and example use for each one.

OUTCOME : Lovely table which gives all the information about different types of operating systems and their uses.

Activity 3 Functions of the operating system (60)

Operating systems act as an interface between human operators and the hardware of the computer. They all perform pretty much the same functions.

Click to enlarge

Together, all the functions of the operating system provide a virtual machine - an interface which hides the true complexity of the hardware from the user. We are most familiar with the top level of this hierarchy which provides the computer user with an interface to the OS ...
  • API - Application Programming Interface;
  • GUI - Graphical User Interface (see the third extension activity);
  • CLI - Command Line Interface;

Task 3.1 Podcast!
Computing textbook / Web browser.

Time to be a little creative. You have to make a podcast (that's tech speak for an audio recording) using headset and Audacity software in which you explain, in as animated a fashion as possible, what the different features of the 5 operating system layers actually do.

As a script and a podcast : You will have to write yourself a script first; research for this can come from the course textbook firstly (if you have one) and then from the WWW in the second instance. Record your script - consider a jingle at the beginning and the end. You can get jingles from Freesound - you have to create a free account to download them.

These are the things you have to include ...
  • Provision of the virtual machine
  • Memory management (including virtual memory and partitioning)
  • Hardware and device management (including buffering)
  • File management
  • Provision of user interface
  • Interrupt handling and scheduling
  • Process management
  • Time slicing, polling and threading

 : Script and an audio file. I would like to listen to the audio file afterwards, so you will have to get it to me somehow. If it's good enough, I'll put it up on this site for others to use for revision and inspiration!

Extension Activities 

How about these?
  • If you are interested in reading and you want to learn about operating systems from somebody who really knows, there is an essay in the resources called In the beginning was the command line by a fantastic author called Neal Stephenson who wrote the classic Cryptonomicon. Read it.

  • Fabulous Computer Stupidities at Rinkworks.

  • If you are interested in graphical user interfaces, especially old ones, head on over to the  Toasty Tech website and check out the GUI gallery. Have a special look at 'Win Shells > Microsoft Bob' ...

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.