Year 11 · Computer Science · Autumn 2 – mid-December

Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Paper 1 practice: topics 4 to 6

Exam practice4.1 Types of software and interrupts5.3 Cyber security6.1 Automated systems

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

You will learn to

  • Answer a timed Paper 1 section on topics 4 to 6.
  • Use the command word and the marks to plan each answer before writing.
  • Use the mark scheme to mark your answers, then update your tracker.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Success criteria

You have got it when you can say:

  • I can finish the section in the time given.
  • I can rewrite my weakest answer so it would earn full marks.
  • I can name my reddest syllabus point in topics 4 to 6.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Retrieval starter

Questions from before. Write your answers, then show them.

  1. Last lesson

    The part of an expert system that applies the rules is the…

    A Knowledge baseB Inference engineC User interface

    B. Inference engine

  2. Last unit

    DNS…

    A Turns a domain name into an IP addressB Encrypts the pageC Stores cookies

    A. Turns a domain name into an IP address

  3. Earlier this year

    The bootloader…

    A Prints documentsB Loads the operating system from storage into RAM at start-upC Translates Python

    B. Loads the operating system from storage into RAM at start-up

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (1 of 11)

System software
Software that runs and manages the computer, such as the operating system and utilities.
Application software
Software that does a task for the user, such as a word processor or game.
Operating system (OS)
System software that manages the hardware, files, memory and programs, and gives the user an interface.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (2 of 11)

Device driver
A small program that lets the OS communicate with one particular device.
Multitasking
Running several programs by giving each a short turn on the processor, so they seem to run at once.
Firmware
Software stored permanently in ROM or flash memory on the hardware.
Bootloader
Firmware that loads the operating system into RAM when the computer is switched on.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (3 of 11)

Interrupt
A signal to the processor that something needs its attention.
Interrupt service routine (ISR)
A small program that deals with one type of interrupt.
Compiler
A translator that turns the whole high-level program into machine code at once and creates an executable file.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (4 of 11)

IDE
Integrated development environment: one program with the tools to write, translate, run and debug code.
Internet
The worldwide network of connected computer networks: the physical infrastructure.
URL
Uniform resource locator: the text address of a web page, made of protocol, domain name and file name.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (5 of 11)

HTTP / HTTPS
The rules for sending web pages; HTTPS adds encryption using SSL.
Web browser
Application software that fetches web pages and renders HTML so you can see them.
DNS
Domain Name System: servers that find the IP address that matches a domain name.
IP address
A number that identifies a device on a network, such as 151.101.0.81.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (6 of 11)

Digital currency
Money that exists only electronically.
Brute-force attack
Trying every possible password or key until the right one is found.
DDoS
Distributed denial of service: flooding a server with requests from many computers so real users cannot reach it.
Malware
Software designed to cause harm, such as a virus, worm, Trojan horse, spyware, adware or ransomware.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (7 of 11)

Phishing
A fake message that tricks the user into clicking a link and giving personal details on a fake site.
Pharming
Malicious code or a tampered DNS server redirects the user to a fake website, even if they type the correct URL.
Social engineering
Manipulating people into breaking normal security rules.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (8 of 11)

Firewall
Hardware or software that checks traffic in and out against rules and blocks anything that breaks them.
Proxy server
A server between the user and the internet that filters requests, hides the user's IP address and caches pages.
SSL
Secure Sockets Layer: a protocol that uses certificates and encryption to secure data between browser and server.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (9 of 11)

Automated system
Hardware and software that do a task without a person controlling them.
Sensor
An input device that measures a physical quantity, such as temperature or light.
Microprocessor
A processor on a single chip that processes data and makes decisions.
Actuator
An output device that causes movement or switches something, such as a motor, valve or heater.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (10 of 11)

Set value
The target value stored in the system that sensor readings are compared with.
ADC
Analogue-to-digital converter: changes an analogue sensor signal into digital data.
Robot
A programmable machine with a mechanical structure, sensors, microprocessors and actuators.
Expert system
An AI system that uses facts and rules to give expert-like advice in one subject.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Key words (11 of 11)

Knowledge base
The part of an expert system that stores facts about the subject.
Rule base
The part of an expert system that stores IF … THEN rules for using the facts.
Interface
The part of an expert system that asks the user questions and shows conclusions and reasons.

4.1 Types of software and interrupts · The explanation · step 1 of 29 · part 1 of 3

Two kinds of software

Software is a set of instructions that tells the hardware what to do. There are two main kinds.

System software runs and looks after the computer itself. The user often does not notice it working.

Application software does a job the user wants done, such as writing an essay or editing a photo.

Application software needs system software underneath it. A word processor cannot run without an operating system.

4.1 Types of software and interrupts · The explanation · step 1 of 29 · part 2 of 3

Two kinds of software (continued)

System softwareApplication software
PurposeRuns and manages the computerDoes a task for the user
ExamplesOperating system, device drivers, utilities (anti-virus, backup, disk defragmenter), compilersWord processor, spreadsheet, web browser, video game, photo editor
Who it servesThe computer and the programs on itThe user
?Why?

System software hides the hard parts of the hardware. That means the people who write apps do not need to know how every printer or disk works.

4.1 Types of software and interrupts · The explanation · step 1 of 29 · part 3 of 3

Two kinds of software (continued)

!Watch out

A web browser is application software, even though it feels like part of the computer. Ask: does it do a task for the user? If yes, it is an application.

4.1 Types of software and interrupts · The explanation · step 2 of 29 · part 1 of 3

The operating system and its nine functions

The operating system (OS) is the most important piece of system software. Examples are Windows, macOS, Linux, Android and iOS.

It sits between the user, the applications and the hardware. It manages everything so that they all work together.

Cambridge lists nine functions. Learn all nine, with an example for each.

4.1 Types of software and interrupts · The explanation · step 2 of 29 · part 2 of 3

The operating system and its nine functions (continued)

OS functionWhat it means in plain wordsExample
Managing filesLets you create, name, save, open, copy, move and delete files and foldersSaving `essay.docx` into a folder called `English`
Handling interruptsResponds to signals that need the processor's attentionPausing a game when you press Esc
Providing an interfaceGives the user a way to talk to the computerIcons, windows and menus (GUI) or typed commands (CLI)
Managing peripherals and driversTalks to devices such as printers through driver softwareInstalling a driver so a new printer works
Managing memoryDecides which program uses which part of RAMKeeping a browser and a music app in separate areas of RAM
Managing multitaskingShares processor time so several programs seem to run at onceMusic plays while you type
Providing a platform for running applicationsGives apps a stable base and services they can useAn app asks the OS to save a file instead of controlling the disk itself
Providing system securityProtects the computer and its data from threatsBuilt-in firewall, security updates, login screen
Managing user accountsKeeps each user's files, settings and permissions separateA student account cannot install software; an admin account can

4.1 Types of software and interrupts · The explanation · step 2 of 29 · part 3 of 3

The operating system and its nine functions (continued)

!Watch out

In the exam, "manages files" alone may not get a mark. Add what it does, for example "lets the user rename and delete files".

4.1 Types of software and interrupts · The explanation · step 3 of 29 · part 1 of 4

Files, interface, peripherals and drivers

Managing files. The OS keeps track of where each file is stored on the disk. It organises files into folders and controls who can open them.

Providing an interface. A GUI (graphical user interface) uses windows, icons, menus and a pointer. A CLI (command line interface) uses typed commands. A GUI is easier to learn; a CLI is faster for experts.

4.1 Types of software and interrupts · The explanation · step 3 of 29 · part 2 of 4

Files, interface, peripherals and drivers (continued)

Peripherals are devices connected to the computer, such as a printer, keyboard or webcam. A device driver is a small program that translates between the OS and one particular device.

The OS also uses buffers and queues for slow devices. For example, it holds a print job in a queue until the printer is ready.

4.1 Types of software and interrupts · The explanation · step 3 of 29 · part 3 of 4

Files, interface, peripherals and drivers (continued)

e.g.Example
A teacher plugs a new printer into a classroom laptop. 1. The OS detects a new device. 2. It finds and installs the right driver. 3. When the teacher clicks Print, the OS sends the job to the print queue. 4. The driver turns the job into commands this printer understands.

4.1 Types of software and interrupts · The explanation · step 3 of 29 · part 4 of 4

Files, interface, peripherals and drivers (continued)

?Why?

Without drivers, the OS would need to know the details of every device ever made. Drivers mean a new device only needs one new small program.

4.1 Types of software and interrupts · The explanation · step 5 of 29 · part 1 of 2

Platform, security and user accounts

Providing a platform for running applications. Apps do not control hardware directly. They ask the OS to do things for them, such as "save this file" or "show this window".

This is why an app written for Android will not run on iOS. Each app is written for one platform.

Providing system security. The OS asks for a password or fingerprint at login. It installs security updates and can run a firewall and anti-malware.

4.1 Types of software and interrupts · The explanation · step 5 of 29 · part 2 of 2

Platform, security and user accounts (continued)

Managing user accounts. Each user has a username and password. The OS keeps their files and settings apart and gives each account its own access rights (what it is allowed to do).

e.g.Example
In a school network: A student account can open its own files and run approved software. A teacher account can also see shared class folders. An administrator account can install software and create new accounts.

The explanation · 25 more steps

More on the lesson page

The lesson page has the rest of the explanation, step by step:

  • Memory and multitasking
  • The layers: hardware, firmware, OS, applications
  • What an interrupt is and how it is generated
  • How the processor handles an interrupt
  • After the ISR: what happens next
  • Brute-force attack
  • Data interception
  • Distributed denial of service (DDoS)
  • Hacking
  • Malware: virus, worm and Trojan horse
  • Malware: spyware, adware and ransomware
  • Phishing and pharming
  • Social engineering
  • Solutions: access levels, anti-malware and authentication
  • Solutions: updates, checking messages and links
  • Solutions: firewalls and privacy settings
  • Solutions: proxy servers
  • Solutions: SSL
  • Matching threats to defences
  • The three parts of an automated system
  • The control loop, step by step
  • Scenarios: industry and transport
  • Scenarios: agriculture and weather
  • Scenarios: gaming, lighting and science
  • Advantages and disadvantages in general

Open the lesson page

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Quick quiz · 1 of 3

The register that holds the address of the next instruction is the…

  1. A Accumulator (ACC)
  2. B Memory address register (MAR)
  3. C Program counter (PC)

C. Program counter (PC)

PC points at the next instruction. MAR holds the address being used right now.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Quick quiz · 2 of 3

Which bus carries the actual data?

  1. A Control bus
  2. B Data bus
  3. C Address bus

B. Data bus

Address bus: where. Data bus: what. Control bus: when and which way.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Quick quiz · 3 of 3

The ALU does…

  1. A Arithmetic and logic
  2. B Storing files
  3. C Fetching instructions

A. Arithmetic and logic

Add, subtract, compare. The control unit does the fetching and decoding.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Exit ticket

Answer on paper before you go. Then check.

  1. Cache is…

    A Small, fast memory beside the CPU for recently used dataB The program counterC The hard disk

    A. Small, fast memory beside the CPU for recently used data Bigger cache means fewer slow trips to RAM.

  2. Which memory is volatile?

    A An SSDB RAMC ROM

    B. RAM Volatile means wiped when the power goes. RAM is; ROM and SSDs are not.

Year 11 · Computer Science · Automated and emerging technologies; Paper 1 practice · Lesson 5 of 5

Homework and the challenge

Homework

The CS 6 quiz; a Paper 1 at home, self-marked.

End-of-unit challenge

End-of-unit test: a full Paper 1 under time (the spring mock).