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A key term generator to display randomised or sequential terms from the OCR GCSE Computer Science (J277) course. Filter terms by topics and 'favourite' tricky terms to focus on later. Perfect for students learning GCSE Computer Science in UK schools. GCSE Key Terms Generator If you see this message, your school may be using a strict network filter which has blocked it. The tool uses basic JavaScript and should work fine on a home network. Use this tool to check your understanding of the OCR GCSE J277 specification's key terms . OCR GCSE Homepage

Learn about ways to measure the success of protection. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 6.4 - Protection Measures Exam Board: OCR Specification: 2016 - Unit 2 Staff Responsibilities It is the staff of an organisation that will spend the most time handling and amending data so the company must have sufficient and effective protection measures in place so that staff are confident in their role and know their responsibilities of information security. Certain staff members may be responsible for types of data within an organisation, such as personal and confidential data. Clearly assigning specific people to roles ensures that they know what their job is and that they are responsible if data is lost. Organisations also need to carefully consider which members of staff have access rights to certain information. If data is sensitive or confidential then the more people that have access to that data , the higher the risk of it being lost or tampered with (accidentally or on purpose). Sensitive data should only be handled and accessed by those who need to use it as part of their job role to limit the chance of data loss. Staff should be trained so that they know how to adequately handle information including basic data security techniques and how to protect data from unauthorised access and loss. Disaster & Recovery Planning With important data often stored on a computer network, it is absolutely vital that a detailed and effective disaster recovery policy is in place in the event of data being lost due to an unexpected disaster. Disasters include natural disasters (e.g. fire, flood, lightning), hardware failure (e.g. power supply unit failing), software failure (e.g. virus damage) and malicious damage (e.g. hacking). There are three clear parts to a disaster recovery policy: Before the disaster: All of the possible risks should be analysed to spot if there are any weaknesses in preparation. Preventative measures should be taken after the analysis, such as making rooms flood-proof or storing important data at a different location . Staff training should take place to inform employees what should happen in the event of a disaster. During the disaster: The staff response is very important – employees should follow their training and ensure that data is protected and appropriate measures are put in place. Contingency plans should be implemented while the disaster is taking place, such as uploading recent data to cloud storage or securing backups in a safe room and using alternative equipment until the disaster is over. After the disaster: Recovery measures should be followed, such as using backups to repopulate computer systems. Replacement hardware needs to be purchased for equipment that is corrupted or destroyed. Software needs to be reinstalled on the new hardware. Disaster recovery policies should also be updated and improved . Assessment and Effectiveness Organisations should conduct information security risk assessments periodically to ensure that their physical and logical measures are up-to-date and that they provide the most effective methods of protection. There may be training drills of what should happen if a disaster or substantial data loss occurs so that the company is prepared . By testing the security measures in place, they can identify any weak-points and fix those highlighted vulnerabilities to minimise the possibility of external and internal data intrusion. As part of an organisation's security assessment, they may identify specific cost impacts . These are necessary financial expenditures to ensure the security of data and systems, such as: Software - e.g. security software such as firewalls may be purchased to protect networked systems. Hardware - e.g. buying secure storage devices and new computer systems. Training - e.g. hiring industry experts to train staff on how to keep data secure. Security - e.g. hiring staff to protect server rooms. Q uesto's Q uestions 6.4 - Protection Measures: 1. Describe why staff are so important when it comes to data protection . [3 ] 2. Explain the steps an organisation should take as part of a disaster recovery plan . Split your answer into before, during and after the disaster. [12 ] 3. Why is it important to conduct information security risk assessments ? [2 ] 4. Describe two cost impacts to a bank of keeping customer data secure. [4 ] 6.3 - Impacts Topic List 6.5 - Physical Protection

Learn about the tools of an integrated development environment (IDE) including the editor, error diagnostics and run-time environment. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). Exam Board: OCR Specification: J277 5.2: Integrated Development Environment Watch on YouTube : IDE Tools An IDE (Integrated Development Environment ) provides programmers with the following facilities (tools ) to help create programs : Editor The editor is software that allows a programmer to enter and edit source code . Editor features may include: Automatic formatting (e.g. automatic indentation). Automatic line numbering (this helps to identify exactly where an error has occurred). Automatic colour coding (e.g. Python IDLE turns loop commands orange and print commands purple). Statement completion (e.g. offering to auto-complete a command as the user is typing.) Error Diagnostics & Debugger Break point The programmer selects a specific line and the program displays the variable values at that point . The code can then be executed one line at a time to find exactly where the error occurs. This process is called single-stepping . Variable Watch / Watch Window cost Displays the current value of a selected variable . A variable can be watched line-by-line to see how the value changes . Trace Logs the values of variables and outputs of the program a s the code is executed line by line . Both tools are used to display information about an error when it occurs, such as the line it occurred on and the error type (e.g. syntax ). These tools may also suggest solutions to help the programmer to find and fix the error . Compilers & Interpreters Both tools convert the source code written by a programmer into machine code to be executed by the CPU. A compiler converts the entire source code into executable machine code at once . After compilation, the program can be run again without having to recompile each time. An interpreter converts source code into machine code line by line . An interpreter must reinterpret the code each time the program is required to run . See 5.1 for both types of translators. A runtime environment allows a program to run on a computer system. It checks for runtime errors and allows users to test the program . A runtime error occurs as the program is being executed , such as dividing a number by zero . A commonly used example is the Java Runtime Environment . This allows programmers to design a program on one platform ( using the programming language Java ) which allows the finished program to then be run on many others systems . A runtime environment enables the tools above such as a trace and breakpoint to be used. Run Time Environment Q uesto's Q uestions 5.2 - Integrated Development Environment: 1. Describe the purpose of each type of IDE tool : a. Editor b. Interpreter c. Compiler d. Error Diagnostics / Debugger e. Break point f. Variable Watch / Watch Window g. Trace h. Runtime Environment [ 2 each ] 5.1 - Languages & Translators Theory Topics

Learn about network topologies including client-server, peer-to-peer, bus, mesh and star. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 3.3 - Network Characteristics Exam Board: OCR Specification: 2016 - Unit 1 Network Topologies Network topology refers to the arrangement of computer systems on a network . Devices in a network topology diagram are often called ' nodes ' . Client-Server Network Clients make requests to a server , the server manages that request and responds . For example, if the user (client) makes a request to access www.csnewbs.com to a web server . Large services like Amazon and Google will need very powerful servers to handle millions of requests a second. The client is completely dependent on the server to provide and manage the information. The server controls network security , backups and can be upgraded to manage higher demand. Disadvantages: Large amounts of traffic congestion will cause the network to slow down . If a fault occurs with the server then the whole network will fail . IT technicians may be required to manage and maintain the network . Malware , such as viruses, can spread quickly across the network. Peer-to-Peer Network For peer-to-peer networks , data is shared directly between systems without requiring a central server . Each computer is equally responsible for providing data. Peer-to-peer is optimal for sharing files that can then be downloaded. Bus Topology The nodes are connected to a bus (a central cable which transfers all data on the network). How it works: The bus transfers data packets along the cable . As the data packets arrive at each computer system, the computer checks the destination address contained in the packet to see if it matches its own address . If the address does not match , the computer system passes the data packet to the next system . If the address of the computer system matches the destination address in the data packet, it is accepted and processed. At both ends of the cable are terminators to mark the end of the bus. Advantages: Because of the simple layout, it is easy to attach another system to the main cable without disrupting the whole network . A bus topology is quick to set up once the main cable has been established making it optimal for temporary networks . A bus topology is cost-effective because it usually contains less cabling than other topologies and requires no additional hardware (like a hub or switch). Disadvantages: Poor security as data packets are passed on to each system on the network. Data collisions are likely - this is when two systems attempt to transfer data on the same line at the exact same time. Resending the data wastes time and slows down the network . The main cable will only have a limited length which can become crowded and slows network speed as more systems are attached. The main cable must also be terminated properly . Token Ring Topology In a token ring network , computer systems are connected in a ring or a loop. How it works: A token (small data packet) is sent around the ring in one direction, being passed from one computer system to the next. A computer seizes the token and includes its own data when it transfers data. As the token arrives at each computer system, the system checks the destination address contained in the packet to see if it matches its own. If the addresses match, the computer processes the data otherwise it ignores it. Advantages: Data collisions are avoided as data packets are transmitted in one direction around the ring. Attaching more systems to a ring topology won't affect the transfer speed as much as other layouts like a bus topology because the data is transferred at a consistent speed . Disadvantages: If any system on the network fails then the whole network fails as the loop is broken and data can't be transferred to all systems. To add a new system to a ring topology the network must be temporarily shut down . Star Topology In a star network , each computer system is connected to a central node: a hub or switch . How it works: Each node is connected to the central node (usually a hub or switch ) and transfers its data packets here. The hub/switch looks at the destination address and transfers the packets to the intended computer only. Advantages: A star topology has improved security because data packets are sent directly to and from the hub / switch in the centre and not necessarily all devices like in a bus or ring topology. New systems can be attached directly to the central system so the network doesn't need to be shut down . System failures of attached computers won't usually cause complete network failure. Transfer speeds are generally fast in a star topology as there are minimal network collisions . Disadvantages: Extra hardware (the hub or switch) is required to be purchased, installed and maintained. If the central system (the hub or switch) fails then the whole network will be unusable until the error is fixed. Mesh Topology In a mesh network, each computer system is connected to every other computer system . How it works: Data packets are transferred to the destination address along the quickest path, travelling from node to node. If a pathway is broken, there are many alternative paths that the packets can take. Advantages: If one cable or system fails then data packets can take an alternative route and still reach the destination address. Because of the large possible number of systems and connections, a mesh topology can usually withstand large amounts of data traffic . New systems can be added to the network without disrupting the entire topology . Disadvantages: Because of the possibly large amount of cables required (especially in a complete mesh topology) this network layout can be expensive to install and maintain . Redundant cabling should be avoided - this is when cables are connected between systems that won't ever need to communicate . Configuration Before a computer system can use a network, three pieces of information must be configured (set up) correctly. IP Address An IP address is used to uniquely identify computer systems on a network , allowing communication between them. An example of an IP address is 195.10.213.120. Default Gateway When data is to be sent from one network to another , it must be sent through a default gateway . This default gateway is usually a router that connects the local network to another network . On many home networks , the default gateway will use the same private IP address : 192.168.1.1 Network managers can use automatic configuration which is quicker and easier to set up . A new device can connect to and use a network automatically , such as free WiFi in an airport. Network managers can also set manual configuration which improves security as new devices can’t be used until the addresses have been configured by a technician . This stops unauthorised devices from connecting to the network. Subnet Mask Subnetting is the act of dividing a physical network into smaller 'sub' networks (known as subnets ) . This helps to reduce traffic and means that users can externally access parts of a network (e.g. emails from home) without having to open the entire network. A subnet mask is used to define these subnets . The mask is used to determine the start and end address of each IP address in a subnet. A common subnet mask is 255.255.255.0 as making the first 3 sections full restricts the fourth section to 256 unique values. For example 113.12.14.230 and 113.12.14.157 are in the same subnet but 114.12.14.127 wouldn't be. Q uesto's Q uestions 3.3 - Network Characteristics: 1 a. Describe how peer-to-peer networks and client-server networks function. 1b. Give one use for both types of network. 2a. Draw and label a diagram for all 6 network topologies . 2b. Describe 2 advantages and 2 disadvantages of each network topology . 3 . What is an IP address ? Why is it necessary for networks? 4. Describe what is meant by a default gateway . 5a. What is subnetting ? 5b. What is the purpose of a subnet mask ? 5c. State a common subnet mask . How many unique devices can be used on a network with this subnet mask? 6. Describe 1 reason why a network manager may use automatic configuration and 1 reason why they may use manual configuration . Advantages: The network can be controlled centrally from the server to easily backup data and update software . Hardware, software and resources can be shared across the network, such as printers, applications and data files . The network allows for improved scalability , meaning more clients can be easily added to the central server . Disadvantages: Without a dedicated server there is no central device to manage security or backups . Backups must be performed on each individual system. Computer performance will decrease with more devices connected to the network, especially if other machines are slow. Advantages: This is a simpler network than client-server to set up as no server is required . Clients are not dependent on a server . Perfect for quickly sharing files between systems , such as downloading media files. 3.2 - Virtualisation Topic List 3.4 - Connection Methods

Learn about the motherboard and the components that are connected to this important piece of computer hardware. The Motherboard What is a motherboard? The motherboard is the main circuit board of a computer that links all other components together. Components can communicate by sending signals and data across pathways called buses . Some components, like the CPU and RAM , are directly installed in special sockets on the motherboard . There are expansion slots for further components like a graphics card . What is connected to the motherboard? Central Processing Unit Random Access Memory Graphics Processing Unit Read Only Memory Cache Memory Sound Card Hard Disk Drive Power Supply Unit What is a motherboard's form factor? Form factor relates to the motherboard's size , shape and how many components it can fit . The three most common form factors are compared below: ATX Micro ATX Mini ITX Standard Small Very Small 32 GB 64 GB 128 GB 7 4 1 Size Max RAM Expansion Card Slots GB stands for gigabytes What ports does a motherboard have? The motherboard contains several ports on the back panel , allowing cables to be connected to input or output data . Below are some of the common ports : USB (Type-A) Connects input devices like keyboards and mice or storage devices like a USB memory stick. USB (Type-C) A newer type of USB that is faster and commonly used to charge devices or transfer data. Ethernet Allows a device to connect to a wired network, most commonly to a router, for internet access. HDMI Connects to a monitor or TV to show the computer's audio and visual output. KS3 Home

The third part of a quick guide to the basics of Python aimed at Key Stage 3 students. Learn about creating and using inputs. Python - #3 - Inputs 1. Asking Questions Input means to enter data into a program. Use the input command to ask a question. You must save the answer into a suitably named variable using the = symbol. Task 1 - Create a new Python program and save the file as 3-Inputs.py Use the picture to help you ask what someone's name is. Run the program and type your name. When you run the program (F5) you can type your answer on any question line in the Python Shell . 2. Asking more Questions There is no limit to how many questions you can ask in Python. It is the most important way to interact with the user of your program. Task 2 - Ask two more questions on topics of your choice. 3. Using Variables in a Sentence When we have printed the answers so far, they have not been very informative! You can print variables together with sentences so that they mean more. Use a comma ( , ) between variables and sentences . Task 3 - Use the pictures to help you add commas and sentences to your program to be more informative. BONUS: After I took the screenshot of my code I added in print lines in the two blanks spaces that print a line of dashes. Try to do the same to make your program easier to read. 4. Using Integers An integer is a whole number . When you are asking a question that you know will have a number for an answer , you need to add int ( before your input. Don't forget to add double close brackets at the end of the question line ! Task 4 - Underneath your previous questions (don't delete anything) ask 2 questions that will have numbers for answers. You must use int ( - see the image for help. Challenge Programs Use everything that you have learned on this page to help you create these programs... Challenge Task 1 - Funny Food Create a new Python program. Save it as ' 3-FunnyFood.py ' Add a comment at the top with your name and the date. Create a program that asks two questions, one for their favourite colour and one for their favourite food. Print a funny sentence using both of their answers. BONUS : Try to use only one print line. Remember: Break up variables in a print line by using commas. When you run it, it could look something like this: Challenge Task 2 - Trivia Question Create a new Python program. Save is as ' 3-Trivia.py ' Add a comment at the top with your name and the date. Create a program that asks the user a trivia question of your choice. Print the correct answer AND their answer. BONUS : Use only one print line. BONUS : Try to use only two lines in total . Remember: Break up variables in a print line by using commas. When you run it, it could look something like this: Challenge Task 3 - Getting to School Create a new Python program. Save it as ' 3-School.py ' Add a comment at the top with your name and the date. Create a program that asks two questions, one for how they get to school and one for how long it takes. Don't forget - use int( and then double close brackets for a number! Print an appropriate response that uses both of their answers. BONUS : Use two separate input lines. BONUS : Try to use only one print line . Remember: Break up variables in a print line by using commas. When you run it, it could look something like this: <<< #2 Variables #4 Calculations >>>

Learn about different types computers such a desktops, games consoles, laptops, smart speakers, smart TVs, smartphones, tablets, augmented reality (AR), virtual reality (VR) and mixed reality (MR) devices. 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) 5.1.2 - Types of Device Watch on YouTube : Types of Device Applications can be developed for a range of different devices , each type of device having its own characteristics and common uses . The characteristics of popular devices, such as laptop and tablets , may be well known, but ensure you know the difference between augmented reality ( AR ), virtual reality ( VR ) and mixed reality ( MR ) devices. Types of Device Common Devices Desktops are powerful and customisable personal computers designed for use at a desk . Game consoles are designed specifically for playing video games , usually connected to a TV . Laptops are portable computers with a built-in screen and keyboard , suitable for work on the go . Smart speakers are voice-controlled devices that play music , answer questions and can control smart home gadgets . Smart TVs have internet access , interactive features and apps for streaming and browsing . Smartphones have internet , GPS and Bluetooth connectivity , apps and communication functions . Tablets use a touchscreen larger than a phone, they are more portable than a laptop and good for browsing and media . Augmented Reality (AR ) is technology that overlays digital images or information onto the real world . Virtual Reality (VR ) uses a computer-generated 3D environment that fully immerses the user , usually with a headset . Mixed Reality (MR ) is a blend of AR and VR where digital objects interact with the real world in real time . Q uesto's Q uestions 5.1.2 - Types of Device: 1. Explain the difference between the three types of 'reality ' devices . [3 ] 2. Justify which devices a streaming service should consider for an app . [4 ] 3. Describe the characteristics of any devices not covered in your responses to Q1 and Q2 . [ 5 ] The AR app Pokémon Go was so popular when it released in 2016 that within the first 6 months players had walked a combined 8.7 billion kilometres ( 200,000 trips around the Earth ). D id Y ou K now? 5.1.1 - Human-Computer Inter. Topic List 5.2 - Visual Design Considerations

Learn how to start a new Greenfoot program and set up the world and actors ready for the next steps in creating a game. Part 1 of the Greenfoot Tutorial for the Eduqas/WJEC GCSE 2016 specification. 1. Setup & Populating the World Greenfoot Tutorial 1. Open Greenfoot This tutorial uses Version 2.4.2 which is the version students are given to use in the WJEC/Eduqas Component 2 exam . Click here for more information and how to download 2.4.2 . If you are using a more recent version the code should still work but the look of the program in the screenshots may be different. In the Component 2 exam of the 2016 WJEC/Eduqas specification you would skip ahead to the New Object Placements stage further down this page as the classes should be set up for you. Watch on YouTube: 2. New Scenario For a new project, click ' Scenario ' and then ' New '. If you are using a more recent version of Greenfoot select ' New Java Scenario '. Save this new project in a suitable location such as a folder named 'Greenfoot' . You may wish to save this project as ' SimpleGame ' or ' ExampleGame '. 3. Setup the MyWorld class The first thing to do is to create a subclass of World called MyWorld which becomes our background object. Right-click on the World class and select 'New subclass... ' Set the New class name to MyWorld . Choose any image from the 'backgrounds ' image category. I have chosen the 'cell.jpg ' image. Click the Compile button in the bottom right of the Greenfoot window to save the program . 4. Create the Main Character class Now to create a new class for the main character. Right-click on the Actor class and select 'New subclass... ' Give the new object an appropriate name and choose a relevant image . I have named my class 'Sheep ' and selected the sheep.png image. 5. Right-click on Actor and create two more classes: Collectable objects to pick up (e.g. my orange) An enemy character to avoid (e.g. my elephant) Don't forget to compile the program. Watch on YouTube: After creating your classes you must move them over to the game world. This is known as populating the world . 1. New Object Placements Right-click on your main character object and select the top option e.g. 'new Sheep()'. Drag your mouse to the world and click to drop it. Complete the following actions: Place 1 main character object. Place 5 collectible objects. Place 2 enemy objects. 2. Save the World Once you have populated your world with objects then right-click anywhere on the background and select 'Save the World '. This saves the positions of each object so that it won't reset every time you start a new game. You can close the MyWorld code that automatically opens when you save the world, we never add any code to this window. Part 2 - Movement (Arrow Keys) >

Learn about data types (integer, real, character, string, Boolean), positive and negative binary, denary, hexadecimal, sign and magnitude, two’s complement, binary addition, binary subtraction, normalisation of floating point numbers, floating point arithmetc, bitwise manipulation, masks (AND, OR, XOR) and character sets (ASCII, Unicode). Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 4.1 - Data Types Specification: Computer Science H446 Watch on YouTube : Data types Denary & binary Sign and magntiude Two's complement Binary addition Binary subtraction Hexadecimal & binary Hexadecimal & denary Floating point Floating point normalisation Floating point addition Floating point subtraction Binary shifts Masks (AND, OR, XOR) Character sets This is a mathematical topic that requires conversion between the binary , denary (decimal ) and hexadecimal number systems . Representing positive and negative binary values is included, as well as adding and subtracting binary numbers and using normalised floating point to represent decimal numbers . Data Types Data types are needed so that the computer knows how to store , process and interpret data correctly . They help ensure that only valid operations are performed on data . For example, you can add two numbers , but not a number and a word . Common data types: Integer : A whole number , e.g. 7 or -12 . Real : A decimal number , e.g. 3.14 or -0.5 . Boolean : A data type with only two possible values - True or False . Character : A single letter , digit or symbol , e.g. ‘k ’, ‘7 ’, or ‘? ’. String : A sequence of characters treated as text, e.g. “CSNewbs ”. Converting from one data type to another is called casting , e.g. age = str(age) would convert the variable age to a string in Python . YouTube video uploading soon Binary Binary is a base-2 number system with all values comprised only of 0 and 1 , e.g. 01011001 . Denary (also called decimal ) is the base-10 number system you grew up learning, with 10 possible values between 0 and 9 , e.g. 453 . Computers use binary because they are built from electronic components (transistors ) that have two states (on and off ), which are easily represented by 1s and 0s . All data processed and stored by the computer (e.g. numbers , text , images and sounds ) are represented in binary . To convert an 8-bit binary value to denary , write 128 - 64 - 32 - 16 - 8 - 4 - 2 - 1 above the binary and add together the values with a 1 underneath . For example, 10101101 is 173 (128 + 32 + 8 + 4 + 1 ). YouTube video uploading soon Storing Negative Numbers -183 Sign and Magnitude and Two’s Complement are two methods of representing negative numbers in binary . In Sign and Magnitude , the most significant bit (MSB ) represents the sign - 0 for positive and 1 for negative - while the remaining bits store the number’s magnitude (value ). For example, in 8-bit form, 0 101 0010 is +82 and 1 101 0010 is -82 . However, this method has two representations of zero (+0 and -0 ), which can cause problems and may give incorrect results if used to add or subtract . In Two’s Complement , negative numbers are represented by inverting all bits of the positive value and adding 1 to the result. This method has only one zero and makes binary addition and subtraction simpler . YouTube video uploading soon YouTube video uploading soon Binary Addition & Subtraction Binary addition works from right to left but only uses the digits 0 and 1 . The key rules are: 0 + 0 = 0 0 + 1 = 1 1 + 0 = 1 1 + 1 = 10 (write down 0 and carry 1 to the next left column ). 1 + 1 = 1 = 11 (write down 1 and carry 1 to the next left column ). If the final addition produces an extra carry bit , it may indicate an overflow error , if the result is too large to fit in the available bits . Binary subtraction can be done using borrowing , similar to denary subtraction , or more commonly by using two’s complement . In two’s complement subtraction , you add the negative version of one number (found by inverting the bits and adding 1 ) to the other to perform subtraction using binary addition rules . YouTube video uploading soon YouTube video uploading soon Hexadecimal 9E8A Hexadecimal is a base-16 number system using the digits 0 to 9 and the letters A to F, where A = 10 and F = 15 in denary . It’s often used in computing because it provides a shorter , more readable way to represent long binary values . For example, two hex digits represent eight binary bits , making conversions quick and efficient . To convert from binary to hexadecimal , split the binary number into groups of four bits (from right to left ) and convert each group into its hex equivalent . Example: 1101 0110 → 1101 (14 → D ) and 0110 (6 ) → D6 . To convert hexadecimal to binary , replace each hex digit with its 4-bit binary equivalent . Example: 2F → 0010 (2 ) and 1111 (15 → F ) → 0010 1111 . The easiest method to convert between denary and hexadecimal is to convert the value to binary first . Example: 26 → 0001 1010 → 1A . YouTube video uploading soon YouTube video uploading soon Floating Point Floating point is a way of representing real (decimal ) numbers in binary using a mantissa and an exponent . It allows computers to store a wide range of values efficiently , including very small and very large numbers . Floating point normalisation means adjusting the number so that the mantissa begins with a 01 (if it is positive ) or 10 (if it is negative ). This ensures the representation is unique and uses all available bits in the mantissa for precision . To add or subtract floating point numbers , the exponents must first be made equal by shifting the mantissa of the smaller number . Once aligned , the mantissas are added or subtracted , and the result is then normalised again to maintain the correct form . YouTube video uploading soon YouTube video uploading soon Binary Shifts A binary shift moves all the bits in a binary number left or right by a set number of places . A left shift moves all bits to the left , filling the empty right-hand bits with zeros . Each left shift multiplies the number by 2 . For example, shifting 0001 0100 (20 ) one place left gives 0010 1000 (40 ). A right shift moves all bits to the right , discarding the rightmost bits . Each right shift divides the number by 2 . For example, shifting 0010 1000 (40 ) two places right gives 0000 1010 (10 ). YouTube video uploading soon Masks A mask is a binary pattern used with bitwise operations (such as AND , OR and XOR ) to manipulate specific bits within a binary value . An AND mask is used to clear (set to 0 ) specific bits . Any bit ANDed with 0 becomes 0 , and any bit ANDed with 1 stays the same . For example, 1011 0110 AND 0000 1111 = 0000 0110 - the mask keeps only the lower four bits . An OR mask is used to set (turn on ) specific bits . Any bit ORed with 1 becomes 1 , and with 0 stays the same . For example, 1010 0000 OR 0000 1111 = 1010 1111 . An XOR mask is used to toggle (invert ) specific bits . Any bit XORed with 1 flips (0 → 1 or 1 → 0 ), while XORed with 0 stays the same . For example, 1010 1010 XOR 0000 1111 = 1010 0101 . YouTube video uploading soon Character Sets A character set is a collection of characters (letters , numbers , symbols and control codes ) that a computer can recognise , store and process . Each character is represented by a unique binary code . ASCII (American Standard Code for Information Interchange ) is an early character set that uses 7 bits to represent 128 characters , including English letters , digits , punctuation and control characters . It’s simple and compact but limited to English and basic symbols . Extended ASCII uses 8 bits for 256 characters . Unicode was developed to overcome ASCII’s limitations by representing characters from all languages and writing systems . It uses up to 32 bits and includes over 140,000 characters , allowing consistent representation of text across different devices and platforms . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Data Types: integer, real, Boolean, character, string Number Systems: binary, denary (decimal), hexadecimal, sign and magnitude, two's complement, binary addition, binary subtraction, floating point, floating point normalisation, floating point addition, floating point subtraction Binary shifts: left shift, right shift Masks: mask, bitwise operator, AND, OR, XOR Character Sets: character set, ASCII, Unicode D id Y ou K now? Gottfried Wilhelm Leibniz , a German mathematician , is credited with inventing the binary number system in the 17th century , hundreds of years before computers existed. Leibniz biscuits are named after him. 3.4 - Web Technologies A-Level Topics 4.2 - Data Structures

Learn how to use App Inventor 2 to create simple programs. Try to complete task 3 on this page. Perfect for Key Stage 3 students to experiment with block coding, objects and properties. App Inventor Task 3 - Munchin' Pizza This page will teach you how to make a simple app that changes pictures when a button is pressed . You can make the app more complex by adding sounds or additional buttons. Step 1: Set up App Inventor 2 Open App Inventor 2 (use the button on the right) and create a new project. You will need to log in with a Google account. Download the picture images from the zipped folder on the App Inventor 2 Basics page here . Once you have downloaded the pizza pictures you will need to upload them. Find the Media tab on the right side of App Inventor and click 'Upload File...' You will need to upload each picture individually. In the Palette tab on the left side, drag two buttons into the middle screen so they look like this: In the Components tab on the right, click on Button1 and click the Rename button at the bottom to change it to Pizza . Then Rename Button2 to Munch . This will help us when we code later as it will be less confusing. Click on the second button (Munch) that you just dragged into the centre then look in the Properties tab on the right and scroll down to Text . Change 'Text for Munch' to something like 'Munch Pizza' . Now click on the first button in the centre (Pizza) and in the Properties tab, click on Image and select the first image. It should be the full slice of pizza. When you have set the image, you might notice it goes a bit crazy. Still in the Properties tab, change the Height and Width to 'Fill parent...' for both. This will make the image fit within the boundaries of the screen. Finally, change the Text for the Pizza button to be blank. Otherwise it will appear on top of the pizza and look odd. So far you should have a button disguised as a pizza and another button that tells you to munch that lovely cheesy deliciousness. If your program does not look like this, read the instructions above again carefully. Step 2: Code Click on the Blocks button in the top right to start adding code. In the Blocks tab on the left side click on Munch and drag the when Munch Click block into the centre. This block will execute any code inside of it whenever the munch button is clicked. In the Blocks tab on the left side click on Logic and drag an if then block and snap it inside the block you just dragged over. Click on the blue cog button and drag four else if blocks inside the if block at the bottom. The blocks at the top will automatically update when you drag the blocks under the if block underneath. Because we are using different images, we need to check which image is currently being displayed, so we know which picture to change to. Firstly we want to check if the first image is being displayed. Connect an = block from the Logic section. Then add a Pizza Image block from the Pizza section. Lastly grab a " " block from the Text section and write the name of your first image inside (e.g. pizza1.jpg) Don't forget the extension (.jpg). But what does this code actually mean? It is checking to see what the current pizza image is. And if it is pizza1.jpg then it is going to... ...change the picture to pizza2.jpg, as if someone has munched the pizza! Grab a set Pizza Image to block from Pizza and then snap another " " block from Text and add the pizza2.jpg text inside. Now that we have written the code to check the current picture and move it to the next one when pressed, we just need to copy this for the other four pizza pictures. Rather than select all the blocks again, right-clicking on the blocks and selecting 'Duplicate' will copy them. Copy each block and then change the values so that if pizza2.jpg is the current image, then it sets it to pizza3.jpg and so on. Make sure that pizza5.jpg sets the image to pizza1.jpg so that it goes round in a loop. Program 3 Complete! Step 3: Run The easiest way to run an app that you have created at home using App Inventor 2 is to download the free MIT AI2 Companion App on your smartphone from the Google Play Store . At the top of the App inventor program on your computer , click on Connect and AI Companion . This will generate a six-digit code you can type into your phone. If your school has the emulator installed, you can also use this to test your app. Extra Step: Challenges 1. Create your own images and upload them . You can easily create your own set of pictures and link them together. Why not try: Eating a different type of food (e.g. cookie or doughnut). A simple scene that changes from night to day. A simple character that changes appearance (like Pikachu powering up a thunder strike with each button press). 2. Add a sound effect whenever a button is pressed . In the video at the top of the page, you'll see I have a 'munch' sound whenever the button is pressed. You could record this sound yourself or use a sound effect site. Once you have got your sound file (it should be short and .mp3) you need to upload it, just like you uploaded your images. In the Designer layout click 'Upload file...' in the Media tab on the right. Then look in the Palette tab on the left side, open the Media section and drag a Sound block into the centre. It will appear underneath the phone screen in a section called 'non-visible components' which is fine. Now click on Properties on the right side and choose the sound file you just uploaded in the Source box. Click on the Blocks button in the top right to start adding the code! In the Blocks tab on the left side, click on Sound1 and drag the call Sound1 Play block directly underneath when Munch click . This will play the sound everytime the button is pressed. 3. Add more buttons . You could add a second clickable button which reverses the pattern and a third button that resets the order back to the first image. Adding new buttons is easy - drag them from the Palette tab in the Designer layout. Change the button text in the Properties tab and the name of the button in the Components tab. To add code, click on Blocks in the top right then you can duplicate the code for Munch by right-clicking and choosing Duplicate. Now just change the values to what you want. If you are making a reset button, you don't need an if then statement, just set the image to your first image when the button is clicked. Keep messing around with the program and have fun! KS3 Home Tasks 4, 5 & 6

Learn about the three elements of computational thinking - abstraction, decomposition and algorithmic thinking. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.1: Computational Thinking Exam Board: OCR Specification: J277 There are three key components to computational thinking (smart problem solving): Abstraction is when you ignore unnecessary information and focus only on the important facts . Abstraction is used because it simplifies a problem to make it less complex . This makes it more straightforward to understand the problem and create a solution . Decomposition is when you break a problem down into smaller tasks so that it is easier to solve . Each individual problem can be separately tested and solved . Decomposition also enables different people to work on the different parts of a larger problem that can later be recombined to produce a full solution . Algorithmic thinking is the final stage as logical steps are followed to solve the problem . The problem is broken down using decomposition into smaller problems . The required data and relevant data structures are considered using abstraction . Watch on YouTube : Abstraction Decomposition Algorithmic Thinking Q uesto's Q uestions 1.1 - Computational Thinking: 1. What does the term 'abstraction ' mean? Why is it important ? [2 ] 2. What is meant by ' decomposition '? Why is it important ? [ 2 ] 3. What is algorithmic thinking ? What does it involve? [3 ] Theory Topics 1.2 - Designing Algorithms

Learn about legislation that covers a wider geographic area including the UNCRPD. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 4.2 - Global Legislation Exam Board: OCR Specification: 2016 - Unit 2 Data Protection Outside of the UK Personal data should not be transferred outside of the UK unless the country receiving the data has adequate data protection laws that match the Data Protection Act (2018) / GDPR (General Data Protection Regulation ). GDPR was introduced in all European Union (EU ) countries in 2018. This set of regulations ensure that personal data is protected and can be sent between EU countries. However, many other countries only have partially adequate data protection laws (such as the USA and Canada) whilst many nations have inadequate or no laws regarding data protection. Click the map button to visit CNIL's website and see exactly which countries have adequate, inadequate and no data protection laws. UNCRPD UNCRPD stands for United Nations Convention on the Rights of Persons with Disabilities . This is a United Nations human right that states disabled people should be able to 'access information systems' (article 9) and 'use digital means to express their opinion' (article 21). Methods of complying with this convention include: Personal data can be sent between European countries (such as the UK) and the United States because of a protection scheme which was known as the 'Safe Harbour ' scheme (between 2000 and 2015) and the 'EU-US Privacy Shield ' (between 2015 and 2020). This provided protection to European data in the US and required both companies engaged in data transaction to sign up to the scheme before personal data could be transferred. The companies must have been assessed as responsible for the security of the data. The scheme was stopped in July 2020 because the European Court of Justice argued it did not adequately protect the personal data of Europeans from government access. Using < alt> text on images so that text-to-speech software can describe the image aloud, for the visually impaired . The tag can be added to the HTML code of an image on a website and will be audibly spoken by specialist reading software. This image contains alt text that can't be seen by a typical viewer but will be read aloud by screen reading software. Accessibility settings . Websites could allow users to change the font size and style or change the background colour to make text easier to read . Wikipedia presents some articles to be listened to if the user is unable to read them. Example Text Example Text Example Text Example Text Q uesto's Q uestions 4.2 - Global Legislation: 1a. What is the problem with transferring data outside of the UK ? [2 ] 1b. Why can personal data be transferred between European countries ? [2 ] 2. Open the CNIL map (use the link on this page and click on a specific country to see its name) and state: Four countries in the EU Two countries with partially adequate protection Two countries with an authority and law (dark purple) Two countries with laws only (light purple) Four countries with no data protection laws [7 ] 3a. What is UNCRPD and why is it important ? [3 ] 3b. Describe what alt text is used for. [2 ] 3c. State three accessibility settings that could affect how easy text is to read . [3 ] EU-US Privacy Shield 4.1 - UK Legislation Topic List 4.3 - Green IT