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Learn about two methods of representing negative numbers in binary - sign and magnitude and two's complement. Based on the 2020 Eduqas (WJEC) GCSE specification. 4.2: Signed Binary Exam Board: Eduqas Specification: 2020 What are Sign and Magnitude and Two's Complement? Sign and Magnitude and Two's Complement are both methods of writing positive and negative binary values . Sign and Magnitude is simpler but will cause incorrect answers if used in binary calculations . Two's Complement is more complex but will generate correct answers when used in binary calculations . Sign & Magnitude The most significant bit (MSB ) is the largest bit of a binary number - the one furthest to the left . The MSB is the sign - it represents whether the binary value is positive or negative . If the sign is 0 then the binary number is positive . If the sign is 1 then the binary number is negative . The other bits represent the magnitude - the value of the binary number. For an 8-bit binary number , the range is -127 to 127 , because only 7 bits are used to define the magnitude. Sign & Magnitude: Problems Sign and magnitude is not commonly used by computers for two main reasons: Performing binary addition and subtraction (see section 4.3 ) will often cause a wrong result . In the example below, -7 + 3 should equal -4 but the result given is 2. + Sign and magnitude creates two different values for 0 - positive 0 and negative 0 which is incorrect. Two's Complement Two's complement is a method of representing positive and negative binary values. It is used often by computers because binary calculations will work correctly and there is only one value for zero. Two's Complement: Denary to Binary To represent a negative value using two's complement follow these steps: Write out the positive value in binary . Start on the right-hand side and move along, copy all 0s until you get to the first 1 . The first 1 is copied too. After the first 1 invert each value (change to its opposite ). So 0 becomes 1 and 1 becomes 0 . 1. 2. 3. Two's Complement: Binary to Denary To convert a binary number to denary using two's complement you must remember that the MSB is a negative value . Just add the numbers with 1 together to work out the denary value . Q uesto's Q uestions 4.2 - Signed Binary: Sign & Magnitude 1. Using sign and magnitude , convert the following values to denary : a. 00011101 b. 11100011 c. 10110110 d. 01001111 [1 each ] 2. Using sign and magnitude , convert the following values to binary : a. 83 b. -13 c. -102 d. -24 [1 each ] 3. Describe two problems when using sign and magnitude . [ 4 ] 4. Using sign and magnitude , the range of numbers that can be represented in 6 bits is from - 31 to + 31 . State the range of numbers that can be represented using sign and magnitude in the following bits: a. 8 bits b. 4 bits [1 each ] Two's Complement 1. Using two's complement , convert the following values to binary : a. -20 b. -49 c. -87 d. -113 [2 each ] 2. Using two's complement , convert the following values to denary : a. 10110010 b. 11101110 c. 01101011 d. 10011111 [2 each ] Watch the video to learn how sign and magnitude is used to represent negative numbers in binary . Watch the video to learn how two's complement is used to represent negative numbers in binary . Watch on YouTube Watch on YouTube 4.1 - Number Systems Theory Topics 4.3 - Binary Calculations

Learn about the purpose and characteristics of the eight application types, including examples. Application types include communication, educational, entertainment, games, lifestyle, productivity, protection & utility and web browsers. Resources based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 1.3.1 - Application Types Watch on YouTube : Application Types There are several types of applications that can be developed , each with a different purpose and common characteristics . There are eight application types you need to know for this 'Fundamentals of Application Development ' unit, including their purpose and common characteristics . Communication Purpose: Communication applications allow users to exchange information with others , most often in real-time . Data can be transferred in a range of formats including text , images and video . Education Purpose: To teach users about specific topics and help people learn new skills . This may be aimed at certain ages or user groups such as those learning a new language . Characteristics of Communication Applications: Has a simple user interface designed for quick and reliable data exchange . Supports multiple formats (text , images , audio , video and files ). Requires a network connection to send and receive data . Often has built-in security and privacy , such as end-to-end encryption . May use presence awareness such as showing ‘typing… ’ or ‘online now ’. Characteristics of Education Applications: It may be structured around learning milestones or long-term goals . Often interactive , such as quick quizzes or regular recaps of topics. Could include different formats of learning (such as text , visuals or audio ). Usually tracks skills or scores over time to show progress in a user-friendly way . Age-appropriate in content and design , possibly with difficulty levels . Examples: WhatsApp, Messenger, Zoom, Slack, Gmail Examples: Duolingo, Kahoot!, Quizlet, Memrise, Anki Entertainment Purpose: To provide enjoyment through formats such as video or audio , often with automatic suggestions based on previous interactions including watched videos , likes or comments . Characteristics of Entertainment Applications: Simple design to focus on keeping users engaged . May include streamed media content or the option to download . Designed for passive or relaxed use , e.g. watching or listening without interacting . Uses algorithms for recommendations based on user preferences . May include social features such as comments or sharing with friends . Examples: Netflix, Disney+, Spotify, YouTube, Twitch Games Purpose: To offer interactive challenges in a fun and possibly competitive way. Games may be played together online or offline for a single-player experience . Characteristics of Game Applications: Based on clear rules and objectives with reward systems , e.g. achievements . High interactivity and quick responsiveness to keep players engaged . Requires graphical rendering , user inputs and sound design . May support local multiplayer or online play with competition , like leaderboards . Often has a range of difficulty levels to keep players challenged . Examples: Minecraft, Fortnite, Among Us, EA Sports FC, Candy Crush Lifestyle Purpose: Supports a healthy and organised way of living . They often help people to manage their daily tasks and form positive personal routines . Productivity Purpose: To support users to complete tasks , manage their time or organise information in a helpful way , all to to maximise productivity . Characteristics of Lifestyle Applications: Often personalised to user preferences or personal data . May use real-time inputs such as location or health data , like steps taken . It may be integrated with smart wearable devices such as a smartwatch . Designed to be used briefly but daily (e.g. checking steps or logging meals ). Encourages improved habits or healthier improvements . Characteristics of Productivity Applications: Has a focus on efficiency , reliability and easy usability . Often allows collaboration and file sharing (e.g. working with colleagues ). Prioritises data organisation and quick access to relevant information . Usually integrated with cloud services or other apps like calendars . It may be designed for professional , personal or educational use . Examples: MyFitness Pal, Noom, Headspace, FitBit, Couch to 5k Examples: Microsoft Word, Calendar, Google Drive, Notion, Trello Protection & Utility Purpose: To secure the computer system against malicious threats and perform housekeeping tasks that maintain stability and a smooth performance . Characteristics of Protection & Utility Applications: Works in the background without frequent user interaction . Often requires permissions to access sensitive data . Needs to be updated frequently , e.g. adding new virus signatures to the database of an antivirus . May be event-driven (e.g. alerts or automatic scans at regular intervals ). Should use low system resources if it needs to be running constantly . Web Browsers Purpose: Accesses , retrieves and displays web pages from web servers . It provides tools like bookmarks , tabs and history to help users easily navigate the interne t. Characteristics of Web Browser Applications: Displays webpages that are built using HTML , CSS and JavaScript . Supports security protocols such as HTTPS , which uses encryption . Enables customisation and user control , e.g. bookmarks , extensions and themes . Contains an address bar to directly type in URLs or search terms . Allows for multiple tabs to run concurrently . Types of Application Examples: Avast Antivirus, CCleaner, 1Password, Battery Saver, Microsoft Defender Examples: Google Chrome, Safari, Mozilla Firefox, Microsoft Edge, Opera Q uesto's Q uestions 1.3.1 - Application Types: 1. Choose four application types and explain how each can be used in a school . [8 ] 2a. For two application types you did not mention in Q1 , explain their characteristics . [6 ] 2a. For the remaining two application types you have not mentioned , explain their purpose . [ 4 ] Minecraft is the best-selling video game of all time , with over 350 million copies sold since its official release in 2011 . D id Y ou K now? 1.2 - Operating Systems Topic List 1.3.2 - Application Software Categories

Learn about algorithms including pseudocode and flowcharts. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.2: Understanding Algorithms Exam Board: Eduqas Specification: 2020 What is an algorithm? An algorithm is a set of instructions , presented in a logical sequence . In an exam you may be asked to read and understand an algorithm that has been written. To prove your understanding you may be asked to respond by actions such as listing the outputs of the algorithm, correcting errors or identifying an error within it. Programmers create algorithm designs as a method of planning a program before writing any code. This helps them to consider the potential problems of the program and makes it easier to start creating source code. There are two main methods of defining algorithms : Defining Algorithms - Pseudocode & Flowcharts Pseudocode Pseudocode is not a specific programming language but a more general method of describing instructions . It should be unambiguous, and it should not resemble any particular kind of programming language (e.g. Python or Java), so it can theoretically be turned into working code in any language. Generally, pseudocode can be written in any way that is readable and clearly shows its purpose. However, the Eduqas exam board advises that pseudocode for the programming exam should follow the conventions below : Annotation { Write your comment in curly brackets} Define data type price is integer firstname is string Declare a variable's value set price = 100 set firstname = "Marcella" Input / output output "Please enter your first name" input firstname Selection (must have indentation) if firstname = "Steven" then output "Hello" + firstname elif firstname = "Steve" then output "Please use full name" else output "Who are you?" end if Iteration (while loop) while firstname ! = "Steven" output "Guess my name." input firstname repeat Iteration (for loop) for i in range 10 input item next i Define a subroutine Declare Sub1 [Subroutine content indented] End Sub1 Call a subroutine call Sub1 Flowcharts A flowchart can be used to visually represent an algorithm. The flowchart symbols are: Algorithm Examples Below are two different methods for representing the same algorithm - a program to encourage people to buy items cheaply at a supermarket. The program allows the price of items in a supermarket to be entered until the total reaches 100. The total price and the number of items entered are tracked as the program loops. Once the total reaches 100 or more, an if statement checks how many items have been entered and a different message is printed if there are 20 or more items, 30 or more items or less than 20 items. Pseudocode Flowchart {This is a program to see how many items you can buy in a supermarket before you spend over £100} total is integer, itemsentered is integer, itemprice is integer set total = 0 set itemsentered = 0 while total < 100 output "enter the price of the next item" input itemprice total = total + itemprice itemsentered = itemsentered + 1 repeat if itemsentered >= 20 then output "You are on your way to saving money." elif itemsentered => 30 then output "You're a real money saver." else output "Look for better deals next time." end if Reading Algorithms In an exam you may be asked to read an algorithm and prove your understanding , most commonly by listing the outputs . Start from the first line and follow the program line by line , recording the value of variables as you go . When you encounter a for loop , repeat the indented code as many times as stated in the range . Example Algorithm: Start NewProgram i is integer maxvalue is integer input maxvalue for i = 1 to maxvalue output (i * i) ??????? output 'program finished' End NewProgram Example Questions: 1. List the outputs produced by the algorithm if the 'maxvalue' input is 5 . 2. State the code that has been replaced by '???????' and what the code's purpose is. Example Answers: 1. Outputs: 1 4 9 16 25 program finished 2. Missing Code: next i Purpose: Moves the loop to the next iteration. Watch on YouTube Q uesto's Q uestions 8.2 - Understanding Algorithms: 1a. Read the algorithm shown on the left and list all outputs in the correct order if the inputs are 2 for height and 72 for weight . 1b. Give the code that is missing from line 25 . 8.1 - Programming Principles Theory Topics 8.3 - Writing Algorithms

Learn about the Central Processing Unit (CPU) and factors such as clock speed. Learn about components within the CPU including the ALU and control unit. The CPU What is the CPU? The CPU CPU stands for C entral P rocessing U nit . The CPU is considered the brain of the computer because it is used to process data and instructions , just like a human brain . Every single type of computer needs a CPU , from desktop computers to laptops , game consoles , even smart TVs and smart watches . The CPU plugs directly into the motherboard in a special socket . What does the CPU do? The CPU works in a cycle (called the FDE cycle ), which it repeats up to billions of times a second . In the FDE cycle , the CPU first f etches instructions from RAM. Next, the CPU d ecodes (understands ) the instructions and finally e xecutes (runs ) them. RAM (Random Access Memory) Instructions CPU (Central Processing Unit) What is clock speed? The clock speed is how many instructions a CPU can carry out per second . Clock speed is measured in gigahertz (GHz ), where 1 GHz = 1 billion cycles per second . The higher the clock speed , the faster the CPU will run , as more instructions can be processed per second . What are the four components of the CPU? The Control Unit (CU ) sends control signals to direct the operation of the CPU . It also decodes instructions as part of the FDE cycle . ALU stands for Arithmetic Logic Unit . It performs simple calculations and compares data . The registers are temporary storage spaces for instructions inside the CPU. They are used in the FDE cycle . Cache memory stores frequently accessed data that the CPU needs to access at very high speeds . What is overclocking and underclocking? Typical clock speed: 3.5 GHz 3.9 GHz 3.3 GHz Overclocking is when the computer's clock speed is increased higher than the recommended speed. This will make the computer perform faster but it can lead to overheating and could damage the computer . Underclocking is when the computer's clock speed is decreased lower than the recommended speed. This will make the computer perform slower but will increase the lifespan of the computer . KS3 Home

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 6 'Guess the Word' Game Create a Python program similar to the hit New York Times puzzle game Wordle . Allow the user to make guesses to match the randomly chosen hidden word , stopping when they get it correct. You can download a list of 5-letter words on this page. You will need to read in each line of the list and randomly select one - don’t forget to import the random library . Check if each letter of the user’s inputted word is in the randomly selected word . If you are using an IDE like Replit you can use the colorama library and the Fore command to turn the text: Green if the letter is in the correct position . Red if the letter is not in the selected word . Yellow if the letter is in the selected word but not in the correct position . Add your own flair and additional features to your program as an extension, including limiting the number of guesses and recording how many attempts it took to get the correct answer. Download a file of 534 5-letter words: For this task, you will need to create a document and include the following sections (with screenshots where appropriate): An introduction to explain the Purpose of your program . A List of Requirements for a successful program. Screenshots of your code (with comments in your code to show understanding). Testing – Create a plan to show how you will test your program and then explanations of any errors that you found and how they were fixed . An Evaluation of what worked, what didn’t, and how you met each of your requirements from your original list. Also, discuss further improvements that you could have made to improve your program. Reminders for this task: You will need a while loop to repeatedly allows the user to enter words until they match the correct word. Section 10 will help you to open, write and r ead from files . Download the file of 5-letter words from the link above. You will need to randomly select a word from the file. The choice command will help. Selection will be necessary to check if each letter in the inputted word matches the letter in the same position in the correct word. String handling is needed to select specific letters in a string. You will need to use .rstrip() on the selected line (word) that you have randomly chosen from the file. This removes any hidden characters that may interfere with checking if it is equal to the inputted word. There are multiple ways to approach this program, and your solution might look different from the example. Break the problem down and focus on one part at a time. Example solution: The word the user enters should be checked , letter by letter , against the letters in the same position in the randomly chosen correct word . Remember that the first letter in a word has the position 0 , not 1. Below is an example of some incomplete code you may wish to use in your solution. ⬅ Extended Task 5 (Colour Collection) Extended Task 7 (Number Game) ➡

This walkthrough will show you how to create a maze game in Scratch . It is split into the following sections: Creating the First Level Choosing the Main Character Animating & Moving the Main Character Back to the Start Adding Score & Time Making Enemies Adding More Levels Extensions Use the links to move between sections easily! 1. Creating the First Level The very first thing to do is to create the level in which our character will move around in! We are going to draw a background from scratch which our hero will run around in to get to the end. Important parts of the pictures are highlighted in yellow ! 1. Select the blank Stage button in the button left to edit the background. Drawing the Background Challenge Task Anchor 1 2. Press on the Backdrops tab. This will show Scratch’s own paint editor on the right. 3. Use the line tool to create straight maze lines on the background. Use the slider at the bottom to increase the width of the line. Remember this is only the first level so don’t make it too difficult. 4. Create a start zone and an end zone with the rectangle tool and then fill them in with the fill bucket tool . You can also change the main background colour using the fill bucket tool. Remember to choose an appropriate level name in the text box at the top. Level Name Rectangle Tool Fill Bucket Tool Make your game more exciting by creating themed levels , like this park background. Other ideas might include a classroom, library or car park. Try switching up the start and end zones by using the circle tool or the line tool and the fill bucket . Come back to this challenge when you are ready to make more levels! 2. Choosing the Main Character Now that you have your first level designed we can make our hero character who is going to navigate the maze and try to get to the end. Picking the main character Anchor 2 1. A character is called a sprite . We will choose a sprite from Scratch’s sprite library . Click on the fairy icon to open the sprite menu. 2. I have selected the Animals category on the left menu. I have chosen the Penguin sprite but choose whichever character you want. 3. Press the Costumes tab and check that your chosen sprite has at least two costumes . We will use these to create animation in the next section to make it look like the sprite is moving. 4. Now that we don’t need the cat anymore we can delete him by right-clicking on his icon and selecting delete . Shrink the Main Character down to size Shrink Tool 5. The sprite is too big for the level background and you will need to shrink them down . Click on the shrink button at the top of the program and then click on the sprite in the paint area to shrink them down. Remember how many times you clicked the sprite to shrink it. You will need to shrink both costumes the same number of times . Here I have shrunk my penguin by 17 clicks when I selected the shrink tool. You can compare the size of your costumes by looking at the image size beneath the icon (e.g. 40 x 53). Picture Size 6. You need to make sure that your sprite is in the centre of the grid otherwise it might cause trouble later when you try to move them. Click on the costume centre button in the top right (it looks like a crosshair ) and drag your sprite into the middle if it is not. Make sure that both costumes are in the centre . Also, give your costumes appropriate names , I have named mine Mr. Penguin 1 and Mr. Penguin 2. Costume Name Costume Centre 3. Animate & Move the Main Character Adding Animation Anchor 3 1. Click on your sprite icon in the bottom left and then on the Scripts tab in the top centre. We will begin using the script blocks and we need to start in the Events category with: ...so drag it over to the script area. This script will run all the blocks that we place beneath it, when the flag is pressed to start the game. 1. 2. You can only add animation if the sprite you chose has at least two different costumes! 2. The second block we need is: ...in the Control category. Every block that we put inside the forever loop block will repeat again and again . We want our character to switch between their costumes infinitely to make it look like they are always walking, which is why we use the forever loop. 3. Click on the Looks category and drag two... ...inside of your forever loop . Use the drop down list (small black triangle on the costume block ) to make one block switch to your first costume and the other block switch to your second costume. 4. In the Control category, drag over two blocks and place one after each of your ‘switch costume to ‘ blocks. 1 second is too long to wait so click on the 1 and change both to 0.5 instead (this is half a second). If you’ve got the code correct so far, when you press the green flag your character should be animated! Moving the Main Character 1. In the Events category drag a into the script area. Change the button from space to ‘up arrow ’ (or any key you like) It is also popular for computer games to use the w key to move up. 2. Click on the Motion category and move over two blocks: and Change the angle of direction from 90 (which is a right turn) to 0 (which is an upwards turn). Now you have just created code to make your character move upwards by ten steps when you press the up arrow! Once you have dragged the blocks when the up arrow is pressed, you can work out how to make your character move down, left and right ALL BY YOURSELF. Add this code in now, before you move on . Rotate the Main Character If you press the green arrow and move your character around you might notice that it doesn't rotate when it moves. Click on the i in the top left of your sprite icon in the bottom left. There are three types of rotation to choose from. Select your preferred style by clicking on one of the three symbols. Full Rotation will turn your sprite up, down, left and right. Horizontal Rotation will only turn your sprite left and right. No Rotation will not turn your sprite at all. it will always appear in the same direction. Anchor 4 4. Back to the Start Starting in the right place We always want the main sprite to start in the green zone when the green flag is pressed to start the game. First drag your sprite to the green zone . Then go to the Motion category and drag over: ...and connect it directly underneath the block you dragged over earlier. Once you’ve added that line of code, click the green flag to make sure that the sprite starts where you want it to . If it doesn’t, then you can change the x (horizontal) and y (vertical) co-ordinates by clicking on the white boxes and changing the values. Back to the start if touching the walls 1. Drag over and connect together the two blocks below: 2. Drag over the two blocks below, put the blue one inside the other and then put them both inside the forever loop : 3. Change the co-ordinates in the blue block you just added so that it matches the same co-ordinates as the block to make the sprite start at the green zone . 4. Now to add the wall detection code! In the Sensing section, drag this block over... ...and put it inside the top of the ‘if then‘ block . Make sure that you put it between the 'if' and 'then' and not underneath. 5. Click once on the box in the ‘touching colour ‘ block and then click the wall or obstacle you want the player to avoid, Now is a good idea to play your game and make sure you can get to the end without being teleported back to the start. If your game is impossible you will need to edit the background – click on the stage icon in the bottom left then the Backdrops tab and edit the walls. Anchor 5 5. Adding Time & Score Recording the Time 1. Click on the Stage icon in the bottom left, we will create new code in the Scripts tab of the stage. DO NOT click the character sprite! Click on the Data category and choose Make a Variable . A variable is something that can change . Call your new variable Time . Adding a Score - The Number of Restarts 2. From the Events category drag: ...then look in the Data category and connect this underneath: ...but it should say Time instead of 'variable'. This code makes the time start at 0 when the game begins. 3. Now we need a loop that increases our variable called Time by 1 every second. First drag over a forever loop : Then place inside of it two blocks: Make sure it says Time instead of variable. Now press the green flag to see the timer go up. 1. In the Data section click on Make a Variable and give it an appropriate name like Restarts . This variable will count how many times we have touched a wall and had to start again. 2. Firstly, go back to the Scripts area for your character – click on the sprite of your main character in the bottom left then the Scripts tab. You need to add two blocks from the Data category: Change variable to Restarts and place it directly underneath the flag. Change variable to Restarts again and place this code directly after the 'go to ' block inside the loop. Now whenever you touch the wall you restart and it records it in the variable called Restarts. 6. Making Enemies Anchor 6 1. Select the fairy icon in the New sprite section to open the Scratch sprite library. 2. From the sprite library choose your enemy . I have selected the polar bear because it fits with my penguin. 3. Select the shrink tool at the top of the program and click on the enemy . Then drag them to where you want them to start . 4. Click on the sprite icon of your enemy then select the Scripts tab. Drag and connect two blocks: 5. From the Control category grab a: ...and place it after the ‘go to ‘ block. Now we will make our enemy glide from his start position to somewhere on our level again and again. Move the enemy to where you want it to go to then add: ...inside the forever loop. Drag another ‘glide ‘ block and place it underneath but change those co-ordinates to the same as the one underneath the the ‘when green flag clicked‘ block. This code makes the enemy move backwards and forwards forever. 6. Make your main character return to the start if they touch the enemy. Click on your main character sprite in the bottom left and then the Scripts tab. You need to copy the exact same code you made earlier to see if the main character is touching the wall , but this time you need to use: ...instead of the touching colour block. Click on the box in the block and select your Main Character . 7. New Levels Anchor 7 Coming Soon To be added soon. This concludes the walkthrough for a Scratch maze game! Try a combination of the suggestions below to add complexity to your game: Using ‘say ‘ or ‘think ‘ blocks in the Looks category to make your sprites say things at certain points (like at the start of a new level). Making your game harder by speeding up enemies in later levels (you could change the number of seconds it takes to glide ) Adding more enemies that only appear in harder levels. Setting a time limit – instead of having your time begin at 0 and increasing by 1 every second, have it start at 30 and decrease by 1 every second. Extensions Anchor 8

Learn about the different protocols used on networks - HTTP, HTTPS, TCP, IP, Ethernet, WiFi, FTP and SMTP. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.5: Protocols Exam Board: Eduqas Specification: 2020 What is a protocol? A protocol is a set of rules that allow devices on a network to communicate with each other . TCP / IP is actually two separate protocols that combine together. TCP / IP (Transmission Control Protocol / Internet Protocol) TCP is a protocol that allows packets to be sent and received between computer systems. It breaks the data into packets and reassembles them back into the original data at the destination. IP is a protocol in charge of routing and addressing data packets . This ensures data packets are sent across networks to the correct destination . It is also an addressing system - every device on a network is given a unique IP address so data packets can be sent to the correct computer system. HTTP is used to transfer web pages over the Internet so that users can view them in a web browser . All URLs start with either HTTP or HTTPS (e.g. https://www.csnewbs.com). HTTPS is a more secure version of HTTP that works with another protocol called SSL ( Secure Sockets Layer ) to transfer encrypted data . You should see a padlock symbol in the URL bar if your connection to that website is secure. HTTP/HTTPS (Hypertext Transfer Protocol) Ethernet is a protocol for wired connections . Ethernet is used at both the data link and physical layers to describe how network devices can format data packets for transmission. WiFi is the main standard for wireless connections . WiFi is actually a brand name that uses a protocol called IEEE 802.11 . Another wireless standard is Bluetooth , for short-range data transfer. Connection Protocols Transfer Protocols FTP ( File Transfer Protocol ) is used to transfer files across a network. It is commonly used to upload or download files to/from a web server . SMTP ( Simple Mail Transfer Protocol ) is a protocol used to send emails to a mail server and between mail servers . Q uesto's Q uestions 3.5 - Protocols: 1. Describe each of the following protocols . It might be helpful to also draw an icon or small diagram for each one: a. TCP [ 2 ] b. IP [ 2 ] c. HTTP & HTTPS [ 3 ] d. WiFi (802.11) [ 1 ] e. Ethernet [ 2 ] f. FTP [ 2 ] g. SMTP [ 2 ] 2. State which protocol would be used in the following scenarios : a. Transferring a music file to a friend over the internet. [ 1 ] b. Sending an email to a family member in America. [ 1 ] c. Using a wireless connection to play a mobile game. [ 1 ] d. Using a webpage to enter a password securely. [ 1 ] e. Watching a video on YouTube. [1 ] 3.4 Network Hardware & Routing Theory Topics 3.6 - 7 Layer OSI Model

A list of programming topics including HTML, Greenfoot, Python. All Programming Topics Python HTML Greenfoot Assembly Language App Inventor 2

Learn how to use variables in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 1d - Using Variables Printing Variables Within Sentences Join sentences and variables together using a plus symbol (+ ). Joining strings together like this is called concatenation . name = "Marina" print( "Hello " + name + ", nice to meet you." ) = Hello Marina, nice to meet you. Remember to use speech marks for your printed statements but no speech marks for variable names . You need to use the + symbol before and after each variable. direction = "north" country = "Wales" print ( "Have you been to the " + direction + " of " + country + "?" ) = Have you been to the north of Wales? Commas can be used an alternative to the + symbol but they will automatically add a space . day = "Saturday" print ( "My birthday is on a" + day + "this year." ) print ( "My birthday is on a" , day , "this year." ) = My birthday is on aSaturdaythis year. My birthday is on a Saturday this year. Using Variables Task 1 ( Pizza Toppings) Use a variable named topping1 and another named topping2. Print a sentence that uses both variables names. Example solution: My favourite pizza is ham and mushroom. Printing Number Variables Within Sentences To join strings and number values then you must use a comma as a plus will not work: cookies = 4 print ( "Munch! There's only" , cookies , "left." ) = Munch! There's only 4 cookies left. You need to use a comma before and after each variable. Using Variables Task 2 ( Stars ) Make a variable named stars and set it to a large number. Print a sentence with the stars variable. Example solution: I think there are 827392012 stars in the sky! Using Variables Task 3 ( Age & Month) Use a variable named age and set it to your current age. Make a variable named month and set it to the month you were born. Remember to use speech marks for text , e.g. month = "August" but no speech marks for numbers (your age). Print a sentence that uses both variables names . Example solution: I am 14 and I was born in August. Using f-Strings Another method of using variables within a printed sentence is to use f-strings . Type the letter f before your output and place your variable names in curly brackets - { } Variables of any data type can be used with f-strings. name = "Tony Stark" alias = "Iron Man" print( f"Did you know {name} is actually {alias} ?" ) = Did you know Tony Stark is actually Iron Man? Using Variables Task 4 ( F-Strings) Create and give a value to three variables : movie_name actor year Use an f-string to print a sentence that uses all three variables. Example solution: Did you know that Harry Potter and the Order of the Phoenix stars Daniel Radcliffe and was released in 2007? ⬅ 1c - Creating Variables Sec tion 1 Practice Tasks ➡

Learn how to read and search through files in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python 10b - Read & Search Files Reading from a File To read and print from a file you must open it in read mode by typing "r" instead of "a". If you are writing and reading in the same program, make sure you close the file in append mode before you open it in read mode . The program below uses the Customers.txt file from the last section. A simple for loop can be used to print each line of the file. The end = "" code just prevents a space between each line. Practice Task 1 Open one of the files that you used in Section 10a and print each line. Example solution: Reading Specific Lines from a File Sometimes it is necessary only to print certain lines. The following example uses a file where I have written a sentence of advice on each line. The user is asked to enter a number between 1 and 6. If they enter 1, the first line of the file is printed. If they enter 2, the second line of the file is printed etc. Remember Python starts counting everything at 0 so each line is a digit less than you would expect . Square brackets must be used to denote the line to print: [1] not (1). The end = "" code is not necessary but removes space after the line. Practice Task 2 Create a text file (saved in the same folder as your Python file) with a list of video games. Ask the user to enter a number between 1 and 10. Print the line for the number that they input. Example solution: Print a Random Line The randint command can be imported and used to print a random line from a file . The example below prints one of the 12 months . The file is opened in read mode and the readlines() command extracts each line , placing them in a list . A random number is then generated between 0 and one less than the total number of lines . This random number is then used to print a line from the extracted list of lines . Python code from random import randint file = open ( "months.txt" , "r" ) lines = file.readlines() random = randint(0,11) print (lines[random]) months.txt January February March April May June July August September October November December potential outputs March December April July If the length of the file is not fixed (e.g. new lines are being added or lines removed ) then the random number generation line can be adapted to use the len command to calculate the current number of lines . This is required to know the upper limit of the random number . random = randint(0,len(lines)-1) Searching Through Files A for loop is used to search through a file , line by line . First, an input line is used to allow the user to enter their search term . If the term that is being searched for is found, then the whole line is printed. The example below uses a variable named found to state if there is a match when the file is searched. If the search term is found, then the found variable is changed to true . If the search term is not found , the found variable remains as false, so the 'no customers found' statement is printed . Practice Task 3 You should have completed Practice Task 2 from Section 10a (the A Level task). Add extra code to that program so that you can search for specific students. Example solution: ⬅ 10a - Open & Write Files 10c - Remove & Edit Lines ➡

Learn about the tags that improve the layout of a web page, including how to centre content and add horizontal lines, bullet points and block quotes. 6. Organisation HTML Guide Watch on YouTube: This page explains the following tags which can be used to structure a simple page layout: Horizontal Line Centre Quote Bullet Points Numbered Points hr Horizontal Line You can add a horizontal line by simply adding to your document. There is no close tag. Add at least one horizontal line to your web page. center Centre Align This tag places the content within the tags on the centre of the page . Be careful - you need to use the American spelling - 'center ' - in your tags. Add tags to place your main heading in the centre of the page. blockquote Blockquote A blockquote is used to display a quote from another person or place. Text is indented further from the margin than the other content. It is not used very often, but can be found in some online articles and essays. Add at least one block quote to your web page. uo list Unordered List An unordered list is a set of bullet points . The tag is placed before the bullet points and afterwards. Each bullet point is placed within tags. That stands for list item . Add either an unordered or ordered list to your web page. Include at least three items in your list. o list Ordered List An ordered list will number each line . The tag is placed before the list and afterwards. Each list item is placed within tags. Add either an unordered or ordered list to your web page. Include at least three items in your list. Next it is time to add tags to the head, including a page title and metadata. 5. Images HTML Guide 7. Head Tags

Learn how to input strings (text) in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 2a - Inputting Text Inputting Text (Strings) in Python A string is a collection of characters (letters, numbers and punctuation) such as: “Wednesday” , “Toy Story 4” or “Boeing 747” . Use the input command to ask a question and let a user input data , which is automatically stored as a string . Variable to save the answer into. Give it a suitable name based on the input. name = input ( "What is your name? " ) = What is your name? Paulina Type your answer directly into the editor and press the Enter key. Statement that is printed to the screen. Leave a space to make the output look clearer. Once an input has been saved into a variable, it can be used for other purposes, such as printing it within a sentence : name = input ( "What is your name? " ) print ( "It is nice to meet you" , name) = What is your name? Jake the Dog It is nice to meet you Jake the Dog Always choose an appropriate variable name when using inputs. colour = input ( "What is your favourite colour? " ) print ( "Your favourite colour is " + colour + "? Mine is yellow." ) = What is your favourite colour? blue Your favourite colour is blue? Mine is yellow. Inputting Text Task 1 ( Holiday) Write an input line to ask the user where they last went on holiday . Write a print line that uses the holiday variable (their answer). Example solution: Where did you last go on holiday? Scotland I hope you had a nice time in Scotland Inputting Text Task 2 ( New Neighbour) Write an input line to ask the user for a title (e.g. Mr, Mrs, Dr). Write another input line for an object . Write a print line that uses both input variables (title and object ). Example solutions: Enter a title: Dr Enter an object: Fridge I think my new neighbour is Dr Fridge Enter a title: Mrs Enter an object: Armchair I think my new neighbour is Mrs Armchair Using a Variable Within an Input To use a variable you have previously assigned a value t o within the input statement you must use + (commas will not work). drink = input ( "What would you like to drink? " ) option = input ( "What would you like with your " + drink + "? " ) print ( "Getting your" , drink , "and" , option , "now...." ) = What would you like to drink? tea What would you like with your tea? biscuits Getting your tea and biscuits now... What would you like to drink? apple juice What would you like with your apple juice? cake Getting your apple juice and cake now... Inputting Text Task 3 ( Name & Game) Ask the user what their name is. Ask the user what their favourite game is. Use their name in the input statement for their game. Print a response with their name and the game they entered. Example solutions: What is your name? Rory Hi Rory, what's your favourite game? Minecraft Rory likes Minecraft? That's nice to know. What is your name? Kayleigh Hi Kayleigh, what's your favourite game? Stardew Valley Kayleigh likes Stardew Valley? That's nice to know. ⬅ Section 1 Practice Ta sks 2b - I nputting Numbers ➡