Lesson video

Hi, I'm Kash, your computer science teacher for the computer systems unit.

Now this unit, is all about how computer systems operate.

From programmes and the operating systems, to the physical components, that store and execute these programmes.

For this unit, you are going to need a pen, some paper, and you are going to need to remove any distractions, that can stop you from concentrating.

Once you've done this, lets begin.

In this lesson, you will learn what the purpose of a computing system is, explore what programmes are, and look at specific examples of programmes, that we often use.

The Antikythera mechanism.

The Antikythera mechanism , was retrieved in 1900 from a Roman shipwreck off the coast, of Antikythera island.

It was constructed sometime, in the first or second century BC.

We now know that it was a complex geared mechanism, that could predict solar eclipses, as well as the position of the moon, and known planets.

There are dozens of documentaries, about the Antikythera mechanism, describing the fascinating attempts to understand its function.

Task one.

Use the worksheet to answer the following questions.

Would you call the Antikythera mechanism, a computer? And how is the mechanism, similar or different to modern computers? To help you answer this questions, you can ask yourself the following questions.

Why would such a mechanism be created? What sort of problem does it solve? Why were computers created? What sort of problems do they solve? Pause the video to complete your tasks.

Resume once you're finished.

Task one.

Antikythera mechanism.

Solution.

So would you call the Antikythera mechanism a computer? Well this depends, on the definition of a computer.

Some would define a computer, as any device that receives input, processes it, and produces output.

In this sense, the mechanism is a computer.

However, in this unit, we'll be using the term computer, only for general-purpose programmable devices.

In this sense, the mechanism is not a computer, the processing is hardwired, and is not prescribed by a programme.

Similarities and differences.

The mechanism receives input, the input is processed, and the output is produced.

The mechanism automates an information processing task, and in this sense , it is similar to a modern computer.

Differences.

The mechanism is purpose-built, to perform a set of specific tasks.

Its operation is hardwired, and cannot be modified, in contrast to modern general-purpose computers, which are programmable.

The Pascaline and the stepped reckoner.

Pascal and Leibniz, designed calculating machines.

Leibniz's machine was the first to add, subtract, multiply and divide.

How are these machines similar, or different to modern computers? So these machines are quite similar, in a sense where, we may mention the whole input, process, output usually takes place, coz we can see some levers there.

Though they are a bit different, because we can't see a monitor, there is no keyboard, and there is no mouse.

Also the process here, is not automated.

You have to manually, turn things around yourself each time.

Automate the process.

Here we have an extract from Leibniz, describing his own machine.

If we wanted to produce a more admirable machine, it could be so arranged, that it would not be necessary, for the human hand to move the machine, from operation to operation.

This could be arranged in the beginning, so that everything should be done, by the machine itself.

What is Leibniz suggesting here? What he is suggesting, is that the more admirable machine, would follow a programme, i.

e programmes so that it performs, the necessary operations automatically.

This idea is a bridge, to modern computers.

Babbage's analytical engine.

Babbage created a programmable machine, that would perform calculations, as specified by instructions, on punched cards.

So therefore, it would automate tasks.

How is this machine similar or different, to modern computers? Write your answers down.

What makes a computer different? What makes a computer different than an appliance, such as a dish washer? The computer is the only appliance, that can do more than one thing.

Toasters toast, refrigerators cool, lamps illuminate.

One appliance, one task.

But the computer can do hundreds of tasks.

The computer doesn't have a specific, well-designed purpose.

What are your thoughts on this claim? Do you think that it's true? What makes a computer different? The purpose of a general-purpose computer, is to execute programmes, that operate on data.

Through each programme, the computer transforms itself, into a machine, that performs a specific task.

This is essentially how Alan Turing described it.

A computer running an astronomy programme, can transform itself to provide the functionality, of the Antikythera mechanism.

A computer running a basic calculator programme, can provide the functionality of the Intricate stepped reckoner, and a computer running a chess programme, can provide the functionality, of an electronic chess machine, and beyond.

Computers are not meant to simply replace existing machines.

They have the potential to provide functionality of machines that we're not able to construct, given the restrictions of the physical world, for example, think of all the virtual worlds that we encounter in games.

And most importantly, they have the potential to provide functionality, that we haven't even conceived of yet.

Software.

Your software.

You use programmes for every task, that you perform on your computer.

The word software simply means programmes.

The word computer, applies to all kinds, of general-purpose computing devices.

Pause the video, and complete the following tasks.

Task two.

Software.

Use the work sheet to complete task two, there are three parts.

Your software, your programmes, and are you sure it's a programme? Resume once you're finished.

Your software, part one solutions.

Can you give an example of a programme, that you use to write documents? The programmes we use to write documents, are called word processors.

So you might have a different one, compared to the ones that we've got here.

However, if you are able to write documents, or type of text paragraphs et cetera in that software, we can class it as a word processor.

The examples we have here, are Microsoft Word, and LibreOffice Writer.

Second question.

Can you give an example of a programme, that you use to visit websites? The programmes we use to visit websites, are called browsers.

Some examples are Mozilla Firefox, Google Chrome, and Safari.

Can you give an example of a programme, that you use to get creative? The programmes in these categories, are called video, image, or sound editing programmes.

Some examples are, Photoshop and GIMP for image editing, and Audacity for sound editing.

Task two.

Your programmes.

Part two.

Solution.

Name at least three additional programmes, that you are familiar with.

So tip here was you can list any apps that you play or you use, because apps are also programmes.

Now the options here are pretty much endless.

So I listed my top three, so YouTube, Netflix, and at the moment TikTok.

I'd love to hear what you've written down so at the end of this lesson, I'll let you know how you can share your answers with me.

Next can you give an example of a programme, you use to get creative? So the example of a programme that I gave here, was Adobe Photoshop, but as I've said, there's lots of different options, you could have had here as well.

You can even have TikTok for your video editing, or even for example Instagram, when you are editing images, or Snapchat when you are adding filters and so on, so the possibilities, are pretty much endless here.

Next.

Task two are you sure it's a programme? Part three solution.

Now the question here was, are video, images and sounds, on your computer programmes? The answer, is no.

They are data.

Programmes are required, to read that data and playback the videos or display the images, or reproduce the sounds.

Task two.

Are you sure its a programme? Part three.

Solution.

So you've probably heard of Android, Linux, macOS, iOS , or Windows.

These all belong to the same category, and they are all known as operating systems. Are they programmes? Yes.

Operating systems are programmes, that are responsible for supervising many aspects of a computer system's operation.

This is why the operating system is the first programme, to be loaded and executed when the computer system begins its operation i.

e boots up.

We are going to learn a lot more about systems, in future lessons.

Executing a programme.

Execute the instruction on task three.

The intelligent piece of paper, to play noughts and crosses, against an opponent.

This will give you an insight, into what it means to execute a programme, and carry out instructions mechanically.

Draw the noughts and crosses three by three grid.

Crosses goes first and is the mechanical player.

Follow the instructions blindly.

Noughts goes second and is the human player.

Play as you like and make sure, crosses follows the instructions.

Pause the video to complete the task.

Using the work sheet, complete task three.

Once you've finished, resume.

I hope you enjoyed the activity.

So if you follow them rules, you're never going to loose a game of noughts and crosses ever again, as long as you go first.

So we'd really like to see the work that you have produced, so you can share your work with Oak National.

If you'd like to, please ask you parent or carer, to share your work on Instagram, Facebook or Twitter, tagging @OakNational, or #LearnwithOak.

Well done today, you should be really proud of yourselves, for working really hard, and I am looking forward to seeing you again.

Take care.