Unit 14 m1

Explain how an operating system can be viewed as an event driven application.

An operating system can be viewed as an event driven application as it requires human input to function there are many ways to show how an operating system can be viewed as an event driven application and I will show you some.

The picture above is showing us the windows 7 start menu to get here we would have to move the mouse and click either the right or the left side depending on your mouse primary click settings.

What we have just done is an event the event is known as a click event. Now that the start menu has opened we have many different events in this menu now we are going to go ahead and click the control panel link event.

Here the computer has opened a new window and closed the start menu, this window is control panel so as you can see this is event driven because of all the tasks we had to do to get to this window form moving the mouse to clicking the icon.

Another way an operating system can be. died as an event driven application is when we insert removable media from a disk to a portable drive of some kind or any USB powered device.

When you insert a USB Emory stick this menu pops up

Here in this menu are five different link which all have a different even behind them, if we selected Use this drive for backup a new window would open in the operating system and allow us to backup certain areas of our computer, but today we are going to select view files even you have clicked this a new window would open showing you what removable media drive you have inserted into the slot on your computer he slot we have inserted our removable media into is E:, when the drive is open in a

It's new window you will be able to see what files are stored in the removable drive.

The next example on how an operating system can be viewed as an event driven application is when we come to turn the computer off, restart the computer, switch users, log off, sleep and hibernate.

All these names are events with different functions behind them.

This is the shutdown menu and when you click like the annotated image shows on the small arrow you get this small side menu pop up this is event driven ans when you click another menu on top of the start menu will display, in this little menu are six different event driven processes each process has a different outcome some are similar but still not the same I will now tell you about all six 

Switch users this is used when you have more than one account on the computer clicking this option will let you keep your computer how it is and switch to another user and they can do what they need to do without closing down anything you have open.

Log off this function will log out the user and close down all of the programs you have open and take you back to another menu where you have the choice to chose which login you would like to use.

Lock this function is so that you can immobilise your computer and to get back onto it you would require a password so this is used for when people are at work places this prevents people from using your machine for these purposes.

Restart this function allows the user to turn their computer off and on again without then having to press the power button once switched on also the restart option can come up when you are installing new programs normally what the program will say is "Please restart the computer to finish the installation." You should get a choice depending on program to restart now or later.

Sleep what is function does is leave all your programs open not close anything down and out your computer In a low power state this is known as sleep mode and when you need to wake up the computer normally you would wiggle the mouse or on some laptops press the power button.

Hibernate this function is for when a user could he running low on battery and not get to a charging point in time what this function will do is almost freeze your computer in a promary state and cannot be changed as the computer will save itself on your drive an when you power up the computer again you will he able to continue where you left off last.