iBytes 1 Computer Systems They're all around us!

Learning objectives By the end of the lesson, you will be able to: define a computer system describe the importance of computer systems in the modern world explain the need for reliability in computer systems explain that there are professional standards in the development, use and maintenance of computer systems and give an example explain that there are ethical, environmental and legal considerations when creating computer systems and give some examples. 2

Computer systems are all around us! Starter Round Robin – with a partner take it turns to list as many different types of computer systems as you can until I say stop. 3

Types of computer system Computer Systems Dedicated General purpose Embedded 4 Has software that times each stage of the washing cycle, sets temperature etc A computer system which forms part of an electronic device Can be used for different reasons according to what needs to be done eg browse internet, play film,, run word processor software

What is a computer system? What does it do? What are the basic component processes that take place in a system? 5

“Four box model” 6 CPU (Processing) CPU (Processing) Input Output Storage

Or it could have five! 7 CPU (Processing) Input Output Backing Storage Main memory

Quick task… How would your day have been different today, if there were no computer systems? Work in pairs, be ready to share you thoughts 8 4: : : : : Minutes Time Up!

They are important! If your mobile wasn’t working right now, it would be inconvenient. 9 If you were up a Lake District mountain, injured, in bad weather with darkness approaching, with poor reception on your mobile and low battery, it could be very dangerous! But could also save your life!

Some examples… 10 Your PC! CCTV Mobile Phone Most Cars Central Heating Vending Machin e Traffic Lights Watch TV Washin g Machin e Gaming Console

The importance of computer systems in the modern world Start with the digital device with the letter for your group. Your partner explains how it uses an embedded computer You partner explains why it is important in our society You explain how it could be used in an environmentally/ethical/legal way Your partner explains how the designer/producer has tried to make this reliable Then rotate roles for the next device, and so on. 11 A.Mobile phone B.School computer network C.Vehicle GPS D.Air traffic control E.Doctor’s appointment booking system

How can we make them more reliable? Computer systems can, and do fail from time to time They have several “single points of failure” which would stop the whole computer working if they fail. We can minimise the risk by adding extra hardware that will take over if there is a failure. 12

Power Failure 13 In case the power supply fails, we can add an extra PSU (Power Supply Unit) If the power fails completely, we can use an Uninterruptible Power Supply (UPS), which is basically a large battery!

Hard Drive Failure Hard drive failure can be very serious! RAID systems use two or more hard drives that each have a copy of the data. RAID drives are often “hot swappable” which means you don’t even have to turn the computer off to change them. 14

Professional standards Systems grow over time. What would happen if the person who made this left the company? 15 Still very complex but at least you could find each cable!

Professional Standards One way to make systems more reliable to get people to keep to the same standards – this will hopefully mean a system is more likely to be successful and satisfy us as users, and also allows different systems to “talk” to each other There are industry standards eg USB, proprietary standards (owned by a particular company) eg Apple, and open standards eg Python 16

Wider issues Computer systems have developed very quickly and they are so useful, that life without them would be unacceptable to most of us. But, this has generated problems which we are still understanding and dealing with: –Ethical issues: what is right and what is wrong, invasions/loss of privacy –Legal issues: laws to protect our data, reduce unauthorised access or modification –Environmental issues: energy use, disposal (e-waste) We will cover these in more detail later in the course 17

Today’s task… 1.Log into Moodle 2.Go to ICT & Computing 3.GCSE Computer Science Systems Architecture 5.iBytes Intro: Computer Systems 6.Download, save and then open the work sheet 7.Complete it and print it by the end of the lesson. (Homework and teacher presentation also available here) 18

Homework Complete the worksheet for 19