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Learn about the components of the Central Processing Unit (CPU) and Von Neumann architecture. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). Exam Board: OCR 1.1a: The CPU Specification: J277 Watch on YouTube : Purpose of the CPU CPU Components Von Neumann Architecture The Central Processing Unit ( CPU ) is the most important component in any computer system. Like many computer components, it is attached to the motherboard . The purpose of the CPU is to process data and instructions by constantly repeating the fetch-execute cycle . CPU Components The Control Unit (CU ) sends control signals to direct the operation of the CPU . Control signals and timing signals are sent to the ALU and other components such as RAM . It also decodes instructions as part of the fetch-execute cycle . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . A register is a temporary storage space for one instruction or address . Different registers are used during the fetch-execute cycle . Cache memory is used to temporarily store data that is frequently accessed . Cache memory is split into different levels . Cache is slower to access than the registers but much faster than RAM . Computer Architecture The way a computer is designed and structured is known as its architecture . The most common type of computer architecture is Von Neumann . It is named after the mathematician John Von Neumann (pronounced Von Noy-man) Von Neumann Architecture A computer with Von Neumann architecture stores both program instructions and data in the same memory (RAM ) and in the same format (in binary ). Instructions (technically called the opcode ) and data (technically called the operand ) are not the same . An instruction is an action to perform and data is the value to be used. For example with the command 'ADD 43 ', ADD is the instruction and 43 is the data . Von Neumann architecture also contains the key CPU components of a control unit , arithmetic logic unit (ALU ), registers and cache memory . Q uesto's Q uestions 1.1a - The CPU: 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] 2. Draw a diagram of the CPU , and l abel the four main components . [ 4 ] 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] d. Cache memory [ 2 ] 4a. Describe the key feature of Von Neumann architecture . [ 2 ] 4b. Explain how an instruction is different to data . [ 2 ] 1.1b - Registers & FE Cycle Theory Topics

Learn how pseudocode and flowcharts are written as part of algorithms. This content is based on the 2016 Eduqas / WJEC GCSE Computer Science specification. Algorithms Pseudocode 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 real 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 flowchart A flowchart can be used to visually represent an algorithm. The flowchart symbols are: Algorithm Example example Pseudocode {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 Stop Flowchart

Learn about methods of protecting data physically including biometrics, security staff and locks. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 6.5 - Physical Protection Exam Board: OCR Specification: 2016 - Unit 2 RFID & Tokens Radio-frequency identification (RFID) uses electromagnetic fields to attach tags to physical objects . RFID tags can be embedded within 'dumb' objects such as clothing, packages and even animals. RFID is used with security tokens (such as an ID keycard ) to permit the access of authorised people to certain areas. RFID can be used by IT companies to track equipment and manage access . Shredding This is the cutting up of documents (paper or CDs ) into small pieces so that they cannot be reassembled and read. Sensitive data on paper or optical disc should be shredded when no longer required. Locks A lock can be used to prevent access to server rooms or sensitive data stores . Only authorised personnel with the right key will have access. Physical Security Measures Backup Backups should be taken regularly and stored at a secure location away from the main site. Backups could also be stored on cloud servers so that any damage to the organisation's building will not affect the backup as well. Biometrics Biometric devices require the input of a human characteristic (such a fingerprint , iris or voice scan ). The biometric data is checked against previously inputted data in a database . A match will allow access to the user. Security Staff Staff may be employed to physically prevent unauthorised people from accessing certain areas of a building where sensitive information is stored. They may check ID keycards or use surveillance like CCTV to monitor who is entering and exiting a secure area. Q uesto's Q uestions 6.5 - Physical Protection: 1. Explain how locks can be used as a physical security method within an organisation. [2 ] 2. Explain what RFID is and how it can be used with tokens as a physical security method. [3 ] 3. Explain how biometric devices can be used as a physical security method. [3 ] 4. Explain how security staff can be employed to protect data. [2 ] 5. What is the purpose of shredding ? [2 ] 6. Why should backups be stored off-site ? [1 ] 6.4 - Protection Measures Topic List 6.6 - Logical Protection

Learn how to add a counter to Greenfoot to keep track of the score. Learn how to add and subtract points to the counter. Part 6 of the Greenfoot Tutorial for the Eduqas / WJEC GCSE 2016 specification. 6. The Counter Greenfoot Tutorial 1. Import the Counter The counter class can be imported into your Greenfoot world. Select Edit in the main Greenfoot window then ' Import Class... ' and choose Counter . Watch on YouTube: The Counter class will appear in the Actor classes list . Right-click on the Counter, choose the ' new Counter() ' option and drag it into the world. Now right-click on the background and select 'Save the World' once you have dragged the counter into the world. 2. Increase the Counter by 1 Two lines of code are required to increase the counter . Add this code when your main character is removing the collectible object . This code allows your main character to access the 'add' method from the Counter class . The method 'add ' just increases the value of the counter by the number in the brackets . To decrease the counter , type a negative value in the brackets, such as -1 . < Part 5 - Play Sounds 3. Compile and Run Click the Compile button at the top of the code editor . Then you can go back to the main Greenfoot window and click Run to test if your counter increases . Click on me if you've got an error that you're stuck with. Part 7 - Extension Ideas >

Learn about the risks of storing and processing data, including accidental deletion and hacking. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 6.2 - Risks Exam Board: OCR Specification: 2016 - Unit 2 Unauthorised Access to Data As part of the security principle of confidentiality , data should only be viewed by individuals with the authorisation to do so. There are two main reasons why data may be viewed by someone who shouldn't - espionage and poor information management . Espionage is the act of collecting data so that it can be used against an organisation - such as a competitor acquiring information about their rival's product before it is launched publicly. If a company has poor information management strategies in place and data is insecurely stored or too many people have access to sensitive information then it is more likely to be viewed by unauthorised persons. Not only would competitors benefit from unauthorised access, but the Data Protection Act (2018 ) would also be broken if personal data was accessed . Accidental Loss of Data Data loss refers to information being irretrievably lost - not just a copy of the file but the original version too so it cannot be accessed in any format . One reason for accidental data loss is equipment failure or a technical error that leads to data corruption , such as a database crash or hard drive failure. Human error is another reason for accidental data loss as an employee might accidentally delete a file or discard an important paper document without realising. If data is accidentally lost then it could mean that hours of data entry and collection will have been for nothing and might delay dependent processes such as analysis and trend recognition. Also, if it was personal data that was lost then the security principle of availability has been broken and the Data Protection Act ( 2018 ) has been breached . Intentional Destruction of Data This is the act of purposely damaging an organisation by deleting or denying access to data . Examples include viruses that corrupt data so that it can no longer be used and targeted malicious attacks such as DDOS (distributed denial of service) attacks or ransomware . Ransomware encrypts files so that they can only be accessed again when certain criteria have been met, usually the affected group having to pay an extortionate fee . When data is intentionally deleted the organisation in question can respond by replacing the data and any infected computer systems / devices or by ignoring the loss and not making the breach public - but having to re-collect / re-analyse the data. Data destruction will usually lead to a loss of reputation as customers won't want to have their information stored in a system they see as unreliable and insufficiently protected . This loss of reputation could lead to customer loss and a decrease in profits . If the loss is ignored and unreported then it could result in a huge loss of trust when it is eventually revealed - like Yahoo who only confirmed a massive data breach that happened in 2013, two years later in 2016. This breach affected all 3,000,000,000 Yahoo accounts and is the largest data breach in the history of the internet. Intentional Tampering with Data This is when data is changed and no longer accurate . This could occur through fraudulent activity such as hacking to change information displayed on a webpage. An example is if a student or a teacher changed exam answers for a better grade. A business example is if a company tampered with financial data to display larger profits and smaller losses than real figures, to boost investment or please stakeholders. If data tampering is found out then it can result in a loss of reputation as that organisation cannot be trusted to report data accurately . If personal data has been altered then the security principle of integrity will have been broken as the data is no longer accurate . Data security methods and protection systems will also need to be reviewed if data has been tampered with, especially if it was an external individual that accessed and changed the data. Employees that tamper with data will be fired and may face legal action . Q uesto's Q uestions 6.2 - Risks: 1. Describe two effects on an organisation for each of the four identified risks . [8 ] 2. Research at least one real-life example for each risk above and describe the consequences of that example, such as the Yahoo data breach. [12 ] 6.1 - Security Principles Topic List 6.3 - Impacts

Learn about how to perform binary addition and binary shifts. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 2.4b: Binary Addition & Shifts Exam Board: OCR Specification: J277 Watch on YouTube : Binary Addition Overflow Errors Binary Shifts Issues with Shifts Binary Addition Binary addition is a method of adding binary values without having to convert them into denary. How to add binary numbers: What is an overflow error? An overflow error occurs when a binary value is too large to be stored in the bits available . With a byte (8 bits ) the largest number that can be held is 255 . Therefore any sum of two binary numbers that is greater than 255 will result in an overflow error as it is too large to be held in 8 bits . What is binary shift? Binary shift is used to multiply and divide binary numbers . The effect of shifting left is to multiply a binary number. The effect is doubled by each place that is shifted . x The effect of shifting right is to divide a binary number. ÷ Shifting by 1 has an effect of 2 . Shifting by 2 has an effect of 4 . Shifting by 3 has an effect of 8 . For example, shifting left by 2 places has an effect of multiplying by 4 . Another example: Shifting right by 3 places has an effect of diving by 8 . How to shift a binary number: Binary Shifts Watch on YouTube Watch on YouTube Q uesto's Q uestions Binary Addition: 1. Explain what an overflow error is. [ 2 ] 2. Add together the following binary values. If an overflow error occurs you must state one has occurred. a. 010110012 and 010001012 [2 ] b. 110110112 and 010111012 [2 ] c. 001101102 and 011010112 [2 ] d. 110110112 and 010101112 [2 ] e. 011011012 and 110101102 [2 ] Binary Shifts: 1a. Draw a diagram to show the effect of multiplying and dividing a binary number . [2 ] 1b. Draw a diagram or table to show the effect a shift has for each place from 1 to 4 . For example, a shift of 1 place has an effect of 2. [4 ] 2. State the effect of the following shifts: a. Shift right by 2 places. b. Shift left by 1 place. c. Shift left 3 places. d. Shift right by 4 places. [ 1 each ] 3. Shift the following binary numbers and state the effect of the shift: a. 10101011 : Shift left by 2 places. b. 11101100 : Shift right by 3 places. c. 00001011 : Shift right by 2 places. d. 01101110 : Shift left by 1 place. [ 2 each ] 2.4a - Number Systems Theory Topics 2.4c - Character Storage

Learn about required internal hardware including the CPU, motherboard and PSU. Find out about ports and expansion cards. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.2 Computer Components Exam Board: OCR Specification: 2016 - Unit 1 This page describe the various components inside of computer systems . The first three are necessary in every type of computer: Processor Motherboard Power Supply Unit The main role of a processor is to manage the functions of a computer system by processing data and instructions . The primary processor of each computer system is the Central Processing Unit ( CPU ). A processor is attached to the motherboard using a connection point called a CPU socket . The motherboard is the main circuit board of a computer on which components such as the CPU and ROM are connected . The motherboard contains PCI slots for expansion cards and ports for external devices to be connected . The power supply unit (PSU ) converts electricity from AC (Alternating Current) from the mains power supply to DC (Direct Current) which the computer system can use . The PSU of desktop computers is internal whereas portable devices require an external 'charger '. Memory Computer memory is split into two types - volatile and non-volatile . Volatile storage is temporary (data is lost whenever the power is turned off ). Non-volatile storage saves the data even when not being powered , so it can be accessed when the computer is next on and can be stored long-term . Random Access Memory (RAM) Read-Only Memory (ROM) Cache Memory RAM is volatile (temporary) storage that stores all programs that are currently running . RAM also stores parts of the operating system to be accessed by the CPU. RAM is made up of a large number of storage locations, each can be identified by a unique address . ROM is non-volatile storage that cannot be changed . ROM stores the boot program / BIOS for when the computer is switched on. The BIOS then loads up the operating system to take over managing the computer. Cache memory is volatile (temporary) storage that stores frequently accessed data . It is very quick to access and faster than other types of memory like RAM because it is stored on the processor itself. RAM ( R andom A ccess M emory) ROM ( R ead O nly M emory) Cache Memory Secondary Storage Magnetic Storage Optical Storage Optical Storage Characteristics: X - Low CAPACITY : 700 MB (CD ), 4.7 GB (DVD ), 25 GB (Blu-ray ). X - Not DURABLE because discs are very fragile and can break or scratch easily. ✓ - Discs are thin and very PORTABLE . X - Optical discs have the Slowest ACCESS SPEED . Magnetic Disks are spelled with a k and Optical Discs have a c. Magnetic Storage Characteristics: ✓ - Large CAPACITY and cheaper per gigabyte than solid state . X - Not DURABLE and not very PORTABLE when powered on because moving it can damage the device. ✓ - Relatively quick ACCESS SPEED but slower than Solid State . Optical storage uses a laser to project beams of light onto a spinning disc, allowing it to read data from a CD , DVD or Blu-Ray . This makes optical storage the slowest of the four types of secondary storage. Disc drives are traditionally internal but external disc drives can be bought for devices like laptops. A magnetic hard disk drive (HDD ) is a common form of secondary storage within desktop computers. A read/write head moves nanometres above the disk platter and uses the magnetic field of the platter to read or edit data. Hard disk drives can also be external and connected through a USB port . An obsolete (no longer used) type of magnetic storage is a floppy disk but these have been replaced by solid state devices such as USB sticks which are much faster and have a much higher capacity. Another type of magnetic storage that is still used is magnetic tape . Magnetic tape has a high storage capacity but data has to be accessed in order (serial access ) so it is generally only used by companies to back up or archive large amounts of data . Solid State Storage Cloud Storage When you store data in 'the cloud ', using services such as Google Drive, your data is stored on large servers owned by the hosting company . The hosting company (such as Google) is responsible for keeping the servers running and making your data accessible on the internet . Cloud storage is typically free for a certain amount of storage and users can buy more storage space when they need it - the scalable nature of this storage type makes it very flexible for businesses. Cloud storage is very convenient as it allows people to work on a file at the same time and it can be accessed from different devices . However, if the internet connection fails , or the servers are attacked then the data could become inaccessible . Cloud storage is also known as 'virtual storage ' because the data is saved remotely , freeing up physical storage space for users on their own devices . There are no moving parts in solid state storage . SSD s (Solid State Drives ) are replacing magnetic HDDs (Hard DIsk Drives) in modern computers and video game consoles because they are generally quieter , faster and use less power . A USB flash drive ( USB stick ) is another type of solid state storage that is used to transport files easily because of its small size. Memory cards , like the SD card in a digital camera or a Micro SD card in a smartphone , are another example of solid state storage. Solid State Characteristics: X - High CAPACITY but more expensive per gigabyte than magnetic . ✓ - Usually DURABLE but cheap USB sticks can snap or break . ✓ - The small size of USB sticks and memory cards mean they are very PORTABLE and can fit easily in a bag or pocket. ✓ - Solid State storage has the fastest ACCESS SPEED because they contain no moving parts . Cloud Storage Characteristics: ✓ - Huge CAPACITY and you can upgrade your subscription if you need more storage. ✓ / X - Cloud storage is difficult to rank in terms of PORTABILITY , DURABILITY and ACCESS SPEED because it depends on your internet connection. A fast connection would mean that cloud storage is very portable (can be accessed on a smartphone or tablet) but a poor connection would make access difficult . Storage Protocols SCSI ( Small Computer System Interface ) is a protocol (set of rules) for attaching external devices to a computer system, such as a printer, storage drive or scanner. SAS ( Serial Attached SCSI ) is an improved version of SCSI that enables many more external devices (up to 128) to be connected at the same time to a computer system. Expansion Cards Expansion cards are dedicated circuit boards with a specific purpose that are attached to the motherboard . Most of the following expansion cards can also exist as integrated components on the motherboard, rather than a separate card. Graphics Card Sound Card Processes graphical data (e.g. videos or animations) and converts it into a displayable output on a monitor . Network Interface Card (NIC) 0010 1011 0101 0101 0110 0111 0101 0001 0101 Sound cards convert analogue sound waves into digital data (binary) when inputting audio through a microphone. Sound cards also convert digital data (binary) into analogue sound waves to output audio through speakers or headphones. 0010 1011 0101 0101 0110 0111 0101 0001 0101 Allows computers to connect to networks (such as the Internet ) and enables them to transfer data to other computers. Transfers data between servers across a network. Fibre channel allows for quick transfer speeds and is primarily used to connect data storage to servers in large data centres. Fibre Channel Card Storage Controller Card Required for the computer to manage and use any attached storage devices . Ports A port is the interface between external devices and the computer . Ports allow data to be transferred from and to these devices. USB Port Connects storage devices such as USB sticks or external hard drives . Connects input devices such as a keyboard or mouse, as well as other devices for data transfer such as a camera or smartphone. Ethernet Port Connects computers to network devices such as a modem or router, allowing access to the internet . FireWire Port Developed for Apple products, FireWire transfers data at a high speed from devices such as camcorders and external hard drives . FireWire supports isochronous devices , meaning data is sent in a steady , continuous stream . SATA Port Allows fast data transfer to external HDD , SSD or optical drives . SD Port Enables data from an SD card to be transferred from a device like a camera to the computer. Micro SD Port Allows data from a micro SD card to be transferred from devices such as smartphones , tablets and handheld games consoles to a computer. Q uesto's Q uestions 1.2 - Computer Components: Vital Components: 1. Describe the purpose of the following components : a. The CPU (Central Processing Unit ) [2 ] b. The motherboard [2 ] c. The PSU (Power Supply Unit ) [2 ] Primary Memory: 2a. What is the difference between primary and secondary memory ? [2 ] 2b. What is the difference between volatile and non-volatile storage ? [2 ] 2c. For each of the three types of primary memory , describe its role and give an example of what it can store. [6 ] Secondary Storage: 3a. For magnetic , optical and solid-state storage rank these three secondary storage mediums in terms of capacity , durability , portability and speed . [9 ] 3b. For the following scenarios justify which secondary storage medium should be used and why it is the most appropriate : Sending videos and pictures to family in Australia through the post. [3 ] Storing a presentation to take into work. [3 ] Storing project files with other members of a group to work on together. [3 ] Backing up an old computer with thousands of file to a storage device. [3 ] Additional Components: 4a. State the purpose of five different expansion cards . [5 ] 4b. What is the purpose of the motherboard ? [2 ] Ports: 5a. Describe the six different ports . [6 ] 5b. What is the difference between SCSI and SAS ? [2 ] 1.1 - Computer Hardware Topic List 1.3 - Computer System Types

Learn about input and output devices used with computer systems. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.1 - Computer Hardware Exam Board: OCR Specification: 2016 - Unit 1 Input Devices An input device allows data, such as text, images, video or sound, to be entered into a computer system. Common input devices: Mouse Keyboard Scanner Controller Microphone Webcam Chip Reader OCR / OMR Scanner Barcode Scanner Graphics Tablet Sensors (e.g. light or temperature) Touch Screen Remote Control Biometric Scanner (e.g. fingerprint or iris) Concept Keyboard Output Devices There are many outputs created by a computer system, including printed documents, on-screen data and sound. Common output devices: Monitor Printer (e.g. inkjet or laser) Plotter Speakers Projector Alarm Light Headphones Touch Screen Braille Terminal Communication devices can be found in 1.5 . Biometric Devices A biometric device uses a human characteristic as part of its security mechanism, such as a fingerprint , iris (eye), face o r voice . Organisations using biometrics must instruct each employee to first input their information to a database , by scanning their fingerprint for example. Whenever the scanner scans a finger it searches in its database to see if the fingerprint matches one that it already holds . Only authorised employees will have already scanned their fingerprints so if there is no match then access is not allowed . Advantages of biometric devices: Security is improved as biometrics can't be shared like passwords can. Even if a password is exposed the system can't be accessed without having the biometric too. Biometric scanners verify that a user is who they claim to be. Using a biometric device (e.g. fingerprint scanner) might be quicker and easier than entering a username and password. Disadvantages of biometric devices: Can be expensive to install and all users must take the time to initially set up by entering their biometric into the database so they will be recognised by the system. Unreliable in that it can be affected by the environment (e.g. dirty fingers can't be used with a fingerprint scanner or voice recognition may not work in a loud environment). Disabled users might not be able to provide the biometric required. Privacy concerns - users might not want their personal characteristics stored on a computer system. Q uesto's Q uestions 1.1 - Computer Hardware: 1. Make a list of 5 input devices and 5 output devices . Challenge yourself to look up and include devices from this page you may not be familiar with. [10 ] 2a. State 3 human features that may be recorded by a biometric device . [3 ] 2b. Describe how a biometric device works . [3 ] 2c. A school is considering installing biometric devices to allow only sixth form students to enter certain parts of the school. Describe 3 advantages and 3 disadvantages to the school of using biometrics in this way. [10 ] Topic List 1.2 - Computer Components

Learn about the cultural, environmental, ethical and legal impacts of technology. Based on the 2020 Eduqas (WJEC) GCSE specification. 11.1: Impacts of Technology Exam Board: Eduqas / WJEC Specification: 2020 + What are the issues created by technology? As the use of computers and technological devices continues to rise every year, this increase brings with it a range of different types of issues . Categories of issues described on this page include: Cultural issues Environmental issues Ethical issues Legal & Privacy issues Cultural Issues Culture relates to society and how different parts of the world vary in terms of computer and internet usage . The Digital Divide This term relates to the gap between those people who have access to modern digital technology (such as computers and the internet) and those who have limited access . 'Limited access' could be devices at home or shared devices or having lower-performance (cheaper) computers and low-speed internet connections. The digital divide can be seen in different ways , such as: People in cities vs. People in rural areas . Younger people vs. Elderly people. Developed countries vs. Developing countries. The digital divide is an important ethical issue because digital technologies have led to numerous international benefits including boosted growth , improved product delivery , enhanced communication and increased opportunities . However, this impact is uneven and these positive impacts are mostly occurring in technologically-advanced regions such as North America , Western Europe and Japan . Regions like some nations in Africa and Central Asia have limited digital infrastructure and government instability , leading to poor internet speeds , high costs and limited resources . Discussion Points: What do you think can be done to bridge the digital divide? Whose job is it to bridge the gap? Who will pay for the technology? Changes to Work The internet , the development of new technologies such as cloud storage and increased video communication have transformed the way that many businesses operate across the world. Staff may be able to work from home or access documents collaboratively outside of the traditional workplace, such as cafes or on public transport. Some jobs have moved abroad to save costs, such as help centres for online issues. Tasks can be outsourced to freelancers in other countries where people are content to be paid less for their time and services. For example, some companies will hire temporary web developers from countries such as India to work for them for a lower salary than local workers. Another change to work that technology has brought is the loss of jobs , especially low-skilled jobs such as factory workers that have seen their roles replaced by technology and automation . However, technology has also created millions of new jobs , including installing and maintaining the machines that replace other roles. Environmental Issues Environmental issues concern the natural world and the negative effects of producing , using and discarding computer systems and devices. Energy and Material Consumption In the past 30 years, the number of technological devices has increased astronomically and thousands of new devices are manufactured each day . These devices need to be assembled using a range of materials , including plastics , metals and some rarer elements and need a considerable amount of electrical power to run. Certain systems like web servers and data centres must be powered on all day , every day, which uses a large amount of energy . Pollution and Waste Generating the electricity to power computers creates pollution - an average PC could require up to 50% more energy per year than a fridge. Computers are difficult to recycle and discarded components can lead to land, water and air pollution due to harmful materials , such as lead and mercury , leaking into the environment. Smartphone trends are also negative for the environment as new devices are released yearly , with minor upgrades that people buy to appear fashionable and up-to-date. To lessen the environmental impact, people should reuse and recycle their devices. Ethical Issues Ethics relates to what is considered right or wrong . Often this is subjective - people may have differing opinions on the issue. Drones Uses of drones: Filming and photography for television, movies and special events. Monitoring pollution levels in the atmosphere. Tracking and monitoring wildlife , such as rhino populations in Africa. Disaster zone response , such as searching for survivors following an earthquake. Delivery companies are developing drones to quickly deliver goods across cities. Drones are used by the military to target sites in other countries, such as American soldiers deploying surveillance drones in Syria. Discussion Points: Should you need a licence to buy and fly a drone? Should drones be used to monitor the public? Like flying CCTV? Should drones be used to deliver items? Like Amazon packages? If a drone hits a plane and it crashes, what should the punishment be? A drone is an unmanned aerial vehicle (UAV ) that is remotely operated and can be used for a wide range of purposes. Self-Driving Cars Self-driving cars (also known as autonomous vehicles ) are currently in the development and testing stage with companies like Tesla and Amazon. Benefits of self-driving cars include: In theory, driving will be safer because cars are less likely to make mistakes that humans do and they can’t become distracted or tired . Self-driving cars should be more fuel-efficient because they take the most direct route to destinations and do not get lost. ‘Drivers’ in the car can perform other tasks instead of driving, such as work or planning. Autonomous vehicles could include trucks and vans to automate the delivery and freight industries . Trucks could drive overnight to deliver goods whereas currently, human drivers must take breaks every few hours. Drawbacks of self-driving cars include: Cars could still crash as code and software processes may fail. The technology is still in development and will be very expensive for the first few years when self-driving cars are available to purchase. Jobs may be lost such as delivery and truck drivers whose vehicles are equipped with self-driving technology. Other industries like motorway services and hotels may also be affected. Discussion Points: Would you trust a car to drive itself? Who is to blame if a self-driving car crashes? The car maker? The people in the car? The software writers? What should happen to the people whose jobs are taken by self-driving vehicles? Artificial Intelligence Artificial Intelligence (AI ) is the act of computers replacing humans to analyse data and make decisions . In recent years AI has become more common in the home and on devices like smartphones; assistants such as Siri and Alexa are prime examples of modern home AI. The weather today is cloudy. Benefits of AI include: Processes are sped up as computers can analyse large amounts of data much quicker than a human. AI can be used when a human is unavailable , such as using a symptom checker on the internet for a minor illness rather than booking and waiting for a doctor. Repetitive or time-consuming tasks can instead be completed by a computer , such as searching and sorting scientific data. Drawbacks of AI include: AI can store and process a lot of personal data , especially personal assistants like Alexa which are always listening for ‘wake words’. This data can be viewed by the company that develops it and could be hacked by attackers. AI is programmed by humans and mistakes in code could have disastrous consequences if the AI is used to make important decisions , such as military deployment. Discussion Points: If a robot harms a human who is to blame? The robot? The programmer? The manufacturer? Us? Would you trust a walking, talking robot assistant in your home? Should AI make decisions for us? Legal & Privacy Issues Legal and privacy issues regard laws that have been introduced by the UK government to protect data, systems and networks from unauthorised access . See 11.2 for explanations about important computing legislation in the UK. Loss of Privacy & Hacking There has been a lot of criticism in the last few years about how internet companies and governments are using personal data to invade privacy and track civilians . Facebook was involved in a scandal with using personal data for reasons that were not the original intention. In reverse, WhatsApp and Apple have been criticised for encrypting messages sent by terrorists that police have been unable to track and read. Every week a new company seems to announce that its data has been hacked . Attackers are constantly using botnets and infected systems to crack poorly secured databases and attempting to phish individuals for usernames and passwords. In the past few years, major hacking breaches include Sony, Yahoo and TalkTalk. Discussion Points: Should the UK government be able to see the websites you have visited in the last year? What should happen if a major company is hacked and bank details are stolen? Should they be fined? Pay customers? Prison? Should WhatsApp allow authorities to access encrypted messages? What if they know a terrorist is using it to communicate? Should the UK debate privacy laws before they go into place? Online Crime Unlawfully obtaining personal information and using it for identity theft or fraud . Harassment and threatening others on social media or private messages; blackmail . Cyber attacks are more common - see 3.8 for information about DOS attacks , IP spoofing , SQL injection and more. Sharing copyrighted material such as television programmes, music and video games. Distributing prohibited material such as drugs or weapons on the dark web. See 11.2 for explanations about different laws that have been created to tackle online crime . The increased popularity of the internet and the rising number of users has led to a wave of online crime , taking many different forms, including: Q uesto's Q uestions 11.1 - Impacts of Technology: Cultural Impacts 1a. What is the digital divide ? [ 2 ] 1b. Describe 2 examples of how the digital divide can be seen . [ 2 ] 2. Describe in detail 3 ways that technology has changed the way people work . [9 ] Environmental Impacts 1. Describe the different ways that the increasing use of technology negatively impacts the environment . [ 5 ] Ethical Impacts 1a. What is a drone ? [1 ] 1b. Make a list of all of the positive impacts and the negative impacts of using drones . You should have at least 3 on each side. [ 6 ] 2. Describe 2 benefits of using self-driving cars and 2 negative consequences . [4 ] 3. Describe how artificial intelligence can be used for good . [ 2 ] Legal & Privacy Impacts 1. A hack on a bank has occurred. Describe what you think the impacts would be on the following groups of people: a. The customers . b. The bank managers . c. The general public . [ 6 ] 2. Describe 4 different types of online crime . [ 8 ] 10.3 - Programming Errors Theory Topics 11.2 - Legislation

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 about computational methods including problem recognition, decomposition, divide and conquer, abstraction, backtracking, data mining, heuristics, performance modelling, pipelining and visualisation. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 3.1f - Standard Algorithms Watch on YouTube : Bubble sort Merge sort Insertion sort Quick sort Linear search Binary search Djisktra's algorithm A* algorithm The OCR A-Level course requires an understanding of algorithms used for sorting , searching and pathfinding including how they can be used for traversing and how to write them in pseudocode or a high-level programming langauge . Bubble Sort Bubble sort repeatedly compares adjacent items and swaps them if they are in the wrong order . Its advantage is that it is very simple to understand and easy to implement . However, it is extremely slow for large lists , with a worst- and average-case time complexity of O(n²) . It performs slightly better (O(n)) if the list is already nearly sorted and the algorithm is optimised t o detect no swaps . Overall, it is easy but inefficient . YouTube video uploading soon Merge Sort Merge sort is a divide-and-conquer algorithm that repeatedly splits a list into smaller sublists , sorts them recursively and then merges them back together . Its major benefit is that it is consistently fast with a time complexity of O(n log n) in the best , average and worst cases , making it very efficient for large datasets . It is also stable and works well with linked lists . However, a drawback is that it requires additional memory to store the temporary sublists , making its space complexity O(n) . Merge sort is therefore reliable but not memory-efficient . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Insertion Sort Insertion sort works by taking each item and inserting it into the correct position in a growing sorted portion of the list . It is efficient for small or nearly sorted datasets and has a best-case complexity of O(n) , making it useful in real-time systems or hybrid algorithms . However, for large , randomly ordered datasets it becomes slow , with average- and worst-case performance of O(n²) . It uses very little memory space - (O(1) - which is one of its key benefits compared to more complex sorts like merge or quick . YouTube video uploading soon Quick Sort Quick sort is a divide-and-conquer algorithm that chooses a pivot , partitions the list into smaller elements and larger elements , and recursively sorts the partitions . Its main advantage is speed : the average-case time complexity is O(n log n) and it is often faster in practice than merge sort due to good cache performance and in-place partitioning . However, if poor pivot choices are made (e.g., always picking the first item in an already sorted list ), the worst case becomes O(n²) . Despite this, quick sort is widely used because good pivot-selection strategies minimise this risk . YouTube video uploading soon Linear Search Linear search checks each item in a list one by one until it finds the target value or reaches the end . Its benefit is that it works on any list (sorted or unsorted ) and is extremely simple to use and implement . The drawback is inefficiency for large datasets because its best , average and worst time complexity is O(n) . This means the time taken grows directly with the size of the list , making it suitable only for small collections of data . YouTube video uploading soon Binary Search Binary search repeatedly halves a sorted list to locate a target value , making it much faster than linear search . Its key benefit is efficiency : the time complexity is O(log n) for best , average and worst cases , meaning performance scales extremely well with large datasets . However, its major limitation is that the data must be sorted beforehand , and maintaining a sorted list can itself be costly . When this condition is met , binary search is one of the most efficient searching algorithms available. YouTube video uploading soon Dijkstra's Algorithm Dijkstra’s algorithm is a pathfinding algorithm used to find the shortest path from a starting node to all other nodes in a weighted graph with non-negative edge weights . It works by gradually exploring the graph , always choosing the next closest unvisited node , updating the shortest known distances to its neighbours and marking nodes as 'visited ' once the shortest path to them is confirmed . The algorithm continues until all nodes have been processed or the destination is reached , guaranteeing the shortest path . YouTube video uploading soon A* Algorithm The A* algorithm is an informed pathfinding algorithm that also finds the shortest path in a weighted graph , but it uses a heuristic (an estimate of the distance to the goal ) to guide its search more efficiently toward the target . A* combines the actual cost from the start to a node with a heuristic estimate of the remaining distance , allowing it to prioritise exploring nodes that appear more promising . YouTube video uploading soon Q uesto's K ey T erms Sorting Algorithms: bubble sort, flag, pass, merge sort, insertion sort, quick sort, pivot Seraching Algorithms: linear search, binary search, precondition Pathfinding Algorithms: Dijsktra's algorithm, A* algorithm, heuristic D id Y ou K now? Halo: Combat Evolved released on the Xbox in 2001 and introduced groundbreakingly convincing enemy AI for the time. Pathfinding algorithms were used more realistically than older games so that enemies wouldn't just run directly at the player but behaved in different ways depending on the situation , such as cooperating , flanking or retreating by reacting dynamically to the player . 3.1e - Data Structure Algorithms A-Level Topics

The first part of a quick guide to the basics of Python aimed at Key Stage 3 students. Learn about comments and printing. Python - #1 - The Basics 1. Start with Commenting Programmers write A LOT of code. They need to understand exactly what they have written, especially if they are working as part of a team or returning to code after working on other projects. To help them understand what they have written, programmers use comments to annotate (explain) their code . Task 1 - Create a new Python program and use # to write a comment that says your name and the date. Save the file as 1-Basics.py In Python, type the # symbol then your message to write a comment. Comments are not printed when you run a program! It is a good idea to start every program with a comment, so you know what the program is about . 2. Printing to the Screen The most basic and common command you will use in Python is print . Inside the print brackets, you can write a message within speech marks . Your print command should turn purple - don't use any capital letters in Python unless it is inside speech marks! Task 2 - Write a nice message by using the print command, brackets and speech marks. Press F5 to run your program. 3. More Printing You can write multiple print lines one after another to print on different lines. Task 3 - Add two more print lines to your program. You can choose any message that you like. 4. New Lines You can use the special command \n to start a new line . This allows you to write on multiple lines but only use one print line. Use the backslash ( \ ) not the forward-slash ( / ). Task 4 - Use \n to write a 3 sentence conversation in only one line of code. Challenge Programs Use everything that you have learned on this page to help you create these programs... Challenge Task 1 - Days of the Week Create a new Python program. Save it as ' 1-Week.py ' Add a comment at the top with your name and the date. Create a program that prints the days of the week, with each day on a new line. BONUS : Try to use only one print line. BONUS : Have no empty spaces at the start of each line. When you run it, it should look like this: Challenge Task 2 - Conversation Create a new Python program. Save it as ' 1-Conversation.py ' Add a comment at the top with your name and the date. Create a program that prints a 6-line conversation between two people. It is up to you what these two people are talking about. BONUS : Try to use only one print line. BONUS : Have no empty spaces at the start of each line. When you run it, it could look something like this: #2 Variables >>>