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Learn how to play sound files in Greenfoot. Part 5 of the Greenfoot Tutorial for the Eduqas / WJEC GCSE 2016 specification. 5. Play Sounds 1. Check the Sounds Folder Greenfoot Tutorial Sound files must be placed the ' sounds ' folder of your Greenfoot project to be used in the game. In the Component 2 exam of the WJEC / Eduqas 2016 specification , an audio file will be placed in the sounds folder already . For this example game you can download the audio clips to the right and paste them into your sounds folder . Watch on YouTube: Click the audio icon to download a zip folder of the two sound files below . Copy the files into the sounds folder of your Greenfoot project . < Part 4 - Remove Objects 2. Add the playSound Method Add the code to play the sound at the same time as when the collectible object is removed . The name of the file and its extension (e.g. .wav or .mp3 ) must be written in speech marks after the playSound method. Part 6 - The Counter >

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 1 Pete Porker's Pork Pie Emporium Hello, Pete Porker here... I need a new program for customer orders at my bakery . I need the customer to enter how many scotch eggs (49p each ), pork pies (85p each ) and quiche tarts (£1.45 ) they want to order. Next, ask them to confirm their choice . If they are not happy , ask the questions again . If they confirm their choice, print a receipt showing their order and total . To make your program better, you should use validation (either while loops or error handling ) to make sure that a user must enter a correct value. Bronze Award --- Welcome to Pete Porker's Pork Pie Emporium --- Scotch eggs are 45p, pork pies are 85p and quiche tarts are £1.49. Enter the number of scotch eggs to buy: 9 Enter the number of pork pies to buy: 7 Enter the number of quiche tarts to buy: 4 ----- You selected 9 scotch eggs, 7 pork pies and 4 quiche tarts. 9 scotch eggs = £4.05 7 pork pies = £5.95 4 quiche tarts = £5.96 ------- Total: £15.96 There are many ways to create this program, but below are some suggestions : Use inputs with int to let the user enter how many of each item they want. Use total variables , e.g. totaleggs = eggs * 0.45 to work out the total cost for eggs, pies and tarts. Set a finalcost variable by adding the total of the three items together. Use dashes and \n (which makes a new line ) inside speech marks to make your program more presentable . Silver Award --- Welcome to Pete Porker's Pork Pie Emporium --- Scotch eggs are 45p, pork pies are 85p and quiche tarts are £1.49. Enter the number of scotch eggs to buy: 5 Enter the number of pork pies to buy: 3 Enter the number of quiche tarts to buy: 6 ----- You selected 9 scotch eggs, 7 pork pies and 4 quiche tarts. ----- Are you happy with this selection? no Okay, enter your choices again. Enter the number of scotch eggs to buy: 6 Enter the number of pork pies to buy: 2 Enter the number of quiche tarts to buy: 7 ----- You selected 6 scotch eggs, 2 pork pies and 7 quiche tarts. ----- Are you happy with this selection? yes Excellent! Here is your receipt : 6 scotch eggs = £2.70 2 pork pies = £1.70 7 quiche tarts = £10.43 ------- Total: £14.83 There are many ways to improve this program and below are some suggestions : Use a while loop to repeat the input stage until the user is happy with their choices. You will need to ask the user if they are happy with the values that were entered and then use an if statement to repeat the loop if they enter 'no '. Gold Award Example solution: --- Welcome to Pete Porker's Pork Pie Emporium --- Scotch eggs are 45p, pork pies are 85p and quiche tarts are £1.49. Enter the number of scotch eggs to buy: 9 Enter the number of pork pies to buy: 35 Sorry you must enter a number between 1 and 20. Starting again... Enter the number of scotch eggs to buy: 9 Enter the number of pork pies to buy: 20 Enter the number of quiche tarts to buy: 7 ----- You selected 9 scotch eggs, 20 pork pies and 7 quiche tarts. ----- Are you happy with this selection? YES Excellent! Here is your reciept: 9 scotch eggs = £4.05 20 pork pies = £17.00 7 quiche tarts = £10.43 ------- Total: £31.48 There are many ways to make this program even better and below are some suggestions : Include validation so that the user can only enter numbers between 1 and 20 . You will need to use if statements and the and operator to do this. You can include additional features to your program such as rounding the number to two decimal places and including coloured text using the Colorama library (which will only work if you are using an online editor like Replit ). You can use the .lower() command when checking if the user is happy with their choices to automatically accept 'Yes' and 'YES '. If you really want to challenge yourself you could consider outputting the receipt in order from most expensive to least expensive , using if statements to check the three values (although that has not been done in this example on the left). Helpful reminders for this task: Inputting Integers While Loops Calculations Rounding Integers ⬅ 12 - Error Handling Extende d Task 2 (Lottery) ➡

Learn about algorithms including programming principles, variables and sequencing. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.1: Programming Principles Exam Board: Eduqas / WJEC Specification: 2020 + Problem Solving There are four stages to computational thinking (smart problem solving ). Decomposition is when you break a problem down into smaller tasks so that it is easier to solve . Pattern Recognition is the process of identifying similar patterns within a problem . Abstraction is when you ignore unnecessary information and focus only on the important facts . Algorithms are the final stage as step-by-step rules are created to solve the problem . An algorithm is usually written as psuedocode or presented as a flowchart . Programming Constructs There are three constructs (ideas) of programming that most programs will contain: Sequence Structuring code into a logical, sequential order . Selection Decision making using if statements . Iteration Repeating code , often using for loops or while loops . Variables Large programs are often modular - split into subroutines with each subroutine having a dedicated purpose. Local variables are declared within a specific subroutine and can only be used within that subroutine . Global variables can be used at any point within the whole program . Local variable advantages Saves memory - only uses memory when that local variable is needed - global variables use memory whether they are used or not. Easier to debug local variables as they can only be changed within one subroutine. You can reuse subroutines with local variables in other programs. Global variable advantages Variables can be used anywhere in the whole program (and in multiple subroutines). Makes maintenance easier as they are only declared once. Can be used for constants - values that remain the same. Local & Global Variables Constants A variable is data that can change in value as a program is being run. A constant is data that does not change in value as the program is run - it is fixed and remains the same. An example of a constant in maths programs is pi - it will constantly remain at 3.14159 and never change. π π Counts & Rogue Values When using iteration (looping) the loop must eventually be able to stop. A count is a variable that is used to record the current iteration (loop number). A rogue value is an unexpected value that will cause the loop to end . For example by typing "Stop" into a loop that asks for numbers. Self-documenting Identifiers An efficient program will use variables with sensible names that immediately state their purpose in the program. Using variable names like 'TotalNum' and 'Profit' rather than 'num1' and 'num2' mean that other programmers will be able to work out the purpose of the code without the need for extensive comments. Q uesto's Q uestions 8.1 - Programming Principles: Problem Solving 1. What is meant by 'decomposition '? Why is it important ? [2 ] 2. What does the term 'abstraction ' mean? Why is it important ? [2 ] 3. What is pattern recognition ? [2 ] 4a. What is an algorithm ? [1 ] 4b. What are the two ways of writing an algorithm ? [2 ] Programming Constructs 1. Describe and draw a diagram for the 3 programming constructs . [6 ] Variables 1. What is the difference between local and global variables ? [4 ] 2. Describe two advantages of using local variables . [2 ] 3. Describe two advantages of using global variables . [2 ] 4. What is a constant ? Give an example . [2 ] 5. Why is it important to use self-documenting identifiers when programming? [2 ] 6. What is a count ? What is a rogue value ? [2 ] 7.1 - Language Levels Theory Topics 8.2 - Understanding Algorithms

Learn about the main character sets - ASCII (American Standard Code for Information Interchange) and Unicode. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 2.4c: Character Storage Exam Board: OCR Specification: J277 Watch on YouTube : Character Sets ASCII Unicode Text File Size What is a Character Set? A character set is a table that matches together a character and a binary value . Each character in a character set has a unique binary number matched with it . Character sets are necessary as they allow computers to exchange data and humans to input characters . Two common character sets are ASCII and Unicode : H = 01001000 ASCII Unicode ASCII (American Standard Code for Information Interchange ) is a common character set which does not take up much memory space . It is important to understand that the number of characters that can be stored is limited by the bits available - ASCII uses 1 byte (8 bits ) which only gives 256 possible characters . This is enough for the English language but it can’t be used for other languages or all punctuation symbols. Unicode is a more popular character set because it uses 2 bytes (16 bits ) that allow for 65,536 possible characters . The extra byte allows many different languages to be represented , as well as thousands of symbols and emojis . However Unicode requires more memory to store each character than ASCII as it uses an extra byte . Character sets are logically ordered . For example, the binary code for A is 01000001 , B is 01000010 and C is 01000011 as the code increases by 1 with each character. The file size of a text file is calculated as shown below: bits per character x number of characters Example: A small text file uses the ASCII character set (which uses 8 bits per character ). There are 300 characters in the file . 300 x 8 = 2,400 bits This could be simplified as 300 bytes or 0.3 kilobytes . File Size of Text Files 01101010 = 256 possible characters 8 bits (1 byte) 1000101101001111 = 65,536 possible characters 16 bits (2 bytes) Q uesto's Q uestions 2.4c - Character Storage: 1. What is a character set and why are they needed ? [ 2 ] 2. Describe 3 differences between ASCII and Unicode . [6 ] 3. The binary code for the character P in ASCII is 01010000 . State what the binary code for the character S would be. [1 ] 4a. A text file uses the ASCII character set and contains 400 characters . What would the file size be in kilobytes ? [ 2 ] 4b. A text file uses the Unicode character set and contains 150 characters . What would the file size be in kilobytes ? [ 2 ] 2.4b - Binary Addition & Shifts Theory Topics 2.4d - Image Storage

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

A splash page for the previous Cambridge Technicals units - Unit 1 (Fundamentals of IT) and Unit 2 (Global Information). OCR Cambridge Technicals IT Level 3 These pages are based on content from the OCR Cambridge Technicals 2016 Level 3 IT specification . This qualification stopped in July 2025. The pages on the site will remain for at least two years. Unit 1 Fundamentals of IT Unit 2 Global Information

Learn about different formats for presenting data on the internet including webpages, blogs, streamed video and audio, document stores and RSS feeds. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 1.6 - Information Formats Exam Board: OCR Specification: 2016 - Unit 2 The following formats are used to display information on the internet . Web Pages Web pages can be used for a diverse range of purposes including advertising products, reporting information , displaying images and eCommerce (online shopping). There are two types of web page: Static web page Static web pages contain content that is pre-built and remains the same each time the page is loaded . Static web pages are cheaper and easier to create and load quicker ; they use basic HTML. It can be changed by the site editor but will appear the same for everyone who has access to it, such as a classic promotional website for a small company. Dynamic web page Dynamic web pages are generated when they are loaded and can appear different to different users . Dynamic web pages are harder to code but they can be linked to databases to allow them to show personalised content to whoever is viewing the site; they are written in server-side languages like PHP. The Amazon homepage is an example of a dynamic web page as personalised deals based on previous user history will be shown if you are logged in with an account. Blogs Blogs are used to share information with like-minded individuals, such as those who enjoy the same hobbies or beliefs . Charities , game developers and other businesses also use blogs as a way of updating their customer base with what they have done or what they are working on. Blogs can feature multimedia such as text, images, videos and links to other sites. Advantages of Blogs Disadvantages of Blogs ✓ Share information with followers in the format of text, images and video . ✓ Blogs and vlogs can unite people with similar interests , such as a cookery blog or travel vlog. X Takes a lot of effort and time to create posts, especially if videos need to be edited before posting. Potential customers could be lost if blogs aren't updated regularly . X It can be difficult to build up a customer base directly from a blog. Posts must be engaging , researched and correct . Podcasts A podcast is a downloadable audio file , usually on a certain topic such as sports or gaming that can be listened to when convenient for the user. Spotify and Apple Music have a wide library of podcasts. Advantages of Podcasts Disadvantages of Podcasts ✓ Podcasts are not (usually) recorded live , so they can be edited and uploaded at a certain time each week. ✓ Podcasts can be listened to when convenient for the user, so they can't 'miss' it and can catch up when is best for them. ✓ Podcasts are becoming more and more popular , so the possible audience base is growing each year. Celebrity guests are one way to entice more listeners. X Takes time to record a podcast, especially if they need to be edited to add in music or sound effects or to remove mistakes . X It can be difficult to build up an audience directly from a podcast. Podcasts should be on a topic that interests people and spoken in an engaging way. Streamed Audio & Video Streaming is the process of receiving video / audio data in a continuous flow . This allows the user to access the video / audio immediately , without having to wait for the file to download entirely. For example, the BBC provide live radio streaming online for their radio shows and BBC iPlayer allows users to watch 'catch up' programs that previously aired. YouTube is a widely-used streamed video platform and Spotify is a popular streamed audio service. Advantages of Streamed Media Disadvantages of Streamed Media ✓ Streaming does not require data to be downloaded entirely before use - users can watch / listen as soon as the connection starts . ✓ Streaming is harder for users to share than downloading a file . Netflix uses this as a form of piracy protection . X Streaming requires high bandwidth so users may suffer performance issues on slower devices and networks . X Streaming requires a constant network connection compared to downloadable media which can be used when offline / outside. Social Media Channels Social media channels provide a huge amount of data on users in an informal space. Organisations can receive feedback through user posts and comments . Real-time statistics like views, likes and shares provide an insight to user opinion . Social media channels include traditional sites such as Facebook and Twitter as well as business and recruitment platforms such as LinkedIn . Discussion boards and forums , such as Reddit , are increasingly popular for users to discuss similar hobbies and interests such as politics, gaming and healthy eating. Advantages of Social Media Disadvantages of Social Media ✓ Social media can increase a business' online presence as it is online 24/7 for users to comment and interact with posts. ✓ Posts can be shared between users and their contacts, allowing a post to 'go viral' and be seen by potentially millions of viewers . ✓ Posts can be shared in different information styles such as text , images , video or hyperlinks to other websites. ✓ Businesses can use social media to communicate with their customer s , such as direct messages on Facebook if a customer is unhappy. X Businesses may need to hire a social media manager to interact with customers , update posts and remove spam. X Negative posts can be shared and spread very quickly , such as if a customer complains about how a business treated them poorly. X Businesses must be cautious about what they post , to not accidentally offend others and damage their reputation . Emails Emails can be used to provide information to a large amount of people almost instantly . A company may use an email to advertise new products , inform potential customers of a marketing promotion or target specific users based on previous interactions. Advantages of Emails Disadvantages of Emails ✓ Faster (almost instant) and cheaper (usually free) to send an email compared to traditional letters . ✓ Files can be attached to the email, such as images, videos or forms to complete. ✓ An audit trail can be kept, recording communication between the company and its customers. ✓ Emails can be sent, delivered and read at the user's convenience and to any internet-enabled device across the world . X An internet connection is required to open and read the email. Larger attachments may not open on mobile devices. X Malware can spread through email attachments. Phishers use emails to gain access to personal information and account details . X Some attachments sent via email may be unreadable on different devices / operating systems. X Emails may automatically go into the spam / junk folder and be deleted without being read . Document Stores Document stores allow users to store online files in cloud storage . Common services are Google Drive , Dropbox and Microsoft's OneDrive . Storing documents in the cloud allows users to edit and access them from any location with an internet connection and opens up opportunities for collaboration . Many organisations offer cloud storage space for free up to a certain amount before charging customers for more data. Document stores are very convenient for users and replace the need for portable storage devices like USB sticks. Teachers can use documents stores to share resources with other staff in a school . Documents stores can only be accessed with an internet connection so files will be unavailable during maintenance or network failure. Users rely on the cloud hosting provider, such as Microsoft and Google to keep the data secure and available . RSS Feeds RSS Feeds (short for Rich Site Summary ) allow users to subscribe to updates from their favourite websites. It is a web feed that updates whenever a subscribed site releases new information. For example, the BBC used to post updates for important news headlines which appeared in a subscribed user's RSS feed. As of 2020 most browsers no longer have built-in RSS functionality and it is rarely used . Q uesto's Q uestions 1.6 - Information Formats: 1. Describe the difference between static and dynamic web pages . [4 ] 2. For each type of information format describe its advantages and disadvantages . a. Blogs [8 ] b. Podcasts [8 ] c. Streamed Audio / Video [8 ] d. Social Media [8 ] e. Emails [8 ] 3. Explain how document stores could be used by organisations and individuals . [4 ] 4. Explain what an RSS feed is and how an organisation could use it . [3 ] 1.5 - WWW Technologies Topic List 1.7 & 1.8 - Internet Pros & Cons

Test your understanding of printing, comments and variables. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 1 Practice Tasks Task One: Weekdays Create a program that prints all 5 weekdays , with each day on a new line . Requirements for a complete program: Use only one print line - use \n . No empty space at the start of a printed line. Example solution: Monday Tuesday Wednesday Thursday Friday Task Two: Colour & Animal Sentence Write a program that uses two variables , one for a colour and one for an animal . Print a sentence using both variables . Requirements for a complete program: Use both your variables within one print line. Include capital letters, appropriate punctuation and no irregular spacing in the printed line. Remember: Break up variables in a print line by using commas or plus signs between each part of the "sentence" . Example solutions: Have you ever seen a purple cat? A horse that was green galloped past! Three yellow ants ate my lunch. Task Three: Number, Adjective & Animal Write a program that uses three variables , a number , an adjective (descriptive word) and an animal . Print a sentence using all three variables . Requirements for a complete program: Use all three variables within one print line. Include capital letters, full stops and no irregular spacing in the printed line. Remember: Break up variables in a print line by using commas or plus signs between each part of the "sentence" . Example solutions: What? 64 sneaky elephants just ran past me! There were 12 hungry bears in the park. 85 patient spiders waited in the corner. ⬅ 1d - Using Va riables 2a - Inputting Text ➡

Learn about the different types of LAN, MAN and WAN networks and how to draw network diagrams. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 3.4 - Connection Methods Exam Board: OCR Specification: 2016 - Unit 1 Local Area Network (LAN) A Local Area Network (LAN ) is a network in which the computer systems are all located geographically close to each other , for example, in the same building or on the same site , like a school or office . A type of LAN is a Wired Ethernet LAN ( technically Ethernet is a protocol that controls how data is transmitted over a LAN). Wired Ethernet LANs have a high bandwidth so data can be transferred quickly and because it uses cables the data is harder to intercept than a wireless network. Metropolitan Area Network (MAN) A Metropolitan Area Network (MAN ) connects several LANs together to cover the range of a town or city , for example a university campus network. MANs are usually very efficient at providing fast communication for cities , with high connection speeds through the use of fibre optic cables. Wide Area Network (WAN) A Wide Area Network (WAN ) is a network spanning a large geographical area , such as multiple cities or countries . The internet is the ultimate example of a WAN as it stretches across the entire world. Different types of WAN rules and standards are used: ADSL ADSL ( Asymmetric Digital Subscriber Line ) is a method of transferring data across copper wire telephone lines . ADSL is contended, which means that connection speeds are affected and slowed down by more systems that use the network at the same time . The old copper wires also affect data transfer over long distances and can cause data packet loss . Security is also an issue, as the line is shared with others, making data interception more likely . To improve security, a firewall and/or VPN (Virtual Private Network) may be used. Because ADSL uses the telephone system, a modem is require d at both the sending and receiving ends of the connection. A microfilter is also required to allow internet and telephone access at the same time . ADSL is contended - shared between sites. Internet Service Provider ADSL requires a modem Leased Line Leased Line is a method of providing an uncontended , fixed-bandwidth data connection . The user maintains a dedicated connection that is more secure and, because it is uncontended , will have the same speed all of the time , regardless of how busy the network is . Bandwidth is high , security is better , the connection speed is constant and the network is full-duplex (allowing for data transmission both ways simultaneously). These advantages come at a high cost - possibly hundreds of pounds per month - as well as an expensive installation that can take time to be put in place . As it is a complex configuration , a CSU/DSU (Channel Service Unit/Data Service Unit) device is required to properly terminate the leased line . Internet Service Provider Leased Line is dedicated. C A CSU/DSU is required for a leased line. ISDN ISDN (Integrated Services Digital Network ) transmits video and voice data simultaneously over traditional copper telephone wires . This method uses a circuit-switched network where all data packets take the same route between computer systems. Voice Networks Voice networks primarily transfer audio data using phones and telephone lines . PSTN PSTN (Public Switched Telephone Network ) is the global collection of wired public telephone networks that are used to transmit data over a long distance. PSTN is fixed into position using underground cables and therefore the connection quality is much more consistent than other voice networks. Using a wired connection like a PSTN is more reliable and communication will be clearer than alternatives such as cellular or satellite methods. Cellular Cellular networks require a cell tower (also called a transmitting tower ) to be in close proximity to the communication device. Cellular networks have a greater range than PSTN, but buildings and poor weather can disrupt this point-to-point communication method (where line of sight is necessary ). Each cell tower is also connected to the PSTN . Satellite Satellite networks use point-to-multipoint communication by using satellites above the Earth's atmosphere that receive a transmission and rebroadcast them back to Earth. Because of the distance between the communication device and the satellite (potentially thousands of miles ), there is a delay between data transmission and it being received . Satellite networks are beneficial in remote locations , such as natural disaster zones , where the cell tower may not be present or may be damaged. Transmitting large files using satellites may take longer , and it is not recommended for low-latency needs such as video gaming. There are different types of satellites used in communication and networking : Geostationary satellites are used for consistent communication over a specific region , such as TV broadcasts and weather monitoring . They can also be used to transfer data between remote locations . Low-Earth orbiting satellites are closer to the ground so they enable fast communication for internet services . Medium-Earth orbiting satellites are often used for GPS (Global Positioning System ) and other navigation systems . A global positioning satellite is an example of this type of satellite that provides time and geolocation data to GPS receivers back on Earth. Diagrammatical Representation In an exam, you may be asked to draw a diagram representing how networks are connected . This is different from drawing a network topology (e.g. ring or mesh) and refers to: Connection type (e.g. ADSL / Leased Line). Devices (e.g. router / modem), Security methods (e.g. firewall / VPN) Two LANs connected using a Leased line Two LANs connected using an ADSL line Rules for drawing a network diagram: Label each device and label your LANs . Use appropriate symbols and be neat . There are no set symbols, just be consistent (e.g. both modems are the same shape). ADSL must have a modem and VPN router + Firewall . (ADSL is not very secure so it needs to be protected with the VPN router and firewall. It also uses the telephone line across the internet so it requires a modem at both ends). Leased Line must have a router , a direct connection and CSU/DSU . (Leased line is a secure and direct connection - so it doesn’t need a firewall or VPN router and should be direct (not across the internet )). Q uesto's Q uestions 3.4 - Connection Methods: 1a. What is the definition of a LAN ? [ 2 ] 1b. Describe two benefits of using a wired Ethernet LAN . [ 4 ] 2. What is the definition of a MAN ? [ 2 ] 3a. What is the definition of a WAN ? [ 2 ] 3b. What is the difference between a contended and an uncontended network? [ 2 ] 3 c. Describe the differences between a leased line and ADSL . You should discuss security , connection speed and contention ( contended or uncontended ) . [6 ] 3d. Describe the use of any two network devices required for either a leased line and/or for ADSL . [ 4 ] 3e. Describe the purpose of ISDN . [ 2 ] 4a. Compare the use of PSTN and Cellular methods to make telephone calls . [ 4 ] 4b. Explain 1 way that a satellite network should be used and 1 way it shouldn't be used . [ 4 ] 5. Draw a diagram to show how a leased line or ADSL network can be set up between two existing LANs. [6 ] 3.3 - Network Characteristics Topic List 3.5 - Business Systems

Learn how to delay processes using the sleep command in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 5b - Sleep Using Sleep To pause a program, import sleep from the time library . Type the word sleep followed by the number of seconds that you wish the program to break for in brackets . It must be a whole number . Below is an example of a program that imports the sleep command and waits for 2 seconds between printing: from time import sleep print ( "Hello!" ) sleep(2) print ( "Goodbye!" ) You can implement the sleep command within a for loop to produce an effective timer that outputs each second waited to the screen: You could also use a variable instead of a fixed value with the sleep command such as below: from time import sleep for second in range (1,11): print (second) sleep(1) from time import sleep seconds = int ( input ( "How many seconds should I sleep? " )) print ( "Going to sleep..." ) sleep(seconds) print ( "Waking up!" ) Sleep Task ( Slow Calculator) Create a slow calculator program that needs time to think in between calculations. Print a message to greet the user , then wait 3 seconds and ask them to enter a number . Wait another 3 seconds and ask them to enter a second number . Wait 2 more seconds , print “Thinking…” then 2 seconds later print the total of the two numbers added together . Example solution: ⬅ 5a - Rando m 5c - Date & Time ➡

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 2.2 - Computational Methods Watch on YouTube : Problem recognition Decomposition Divide and conquer Abstraction Backtracking Data mining Heuristics Performance modelling Pipelining Visualisation Computational methods are techniques to analyse problems and design efficient , effective solutions . Problem Recognition Problem recognition is the process of identifying that a problem exists and understanding its nature before attempting to solve it. It involves determining the aims of the task , identifying constraints and requirements , and clarifying what inputs , outputs and processes are expected from the solution . Effective problem recognition ensures the developer understands the real-world context and avoids solving the wrong problem or missing key details . It is the essential first step that guides all later stages of computational thinking and system design . YouTube video uploading soon Decomposition Decomposition involves breaking a complex system or task into smaller , more manageable components that are easier to design , implement and test . Each sub-problem should ideally be independent and solve a specific part of the overall task , which helps reduce complexity and supports modular program design . This approach enables different developers to work on different components simultaneously and simplifies debugging , maintenance and future updates . By working through smaller logical parts , the full problem becomes far more approachable and structured . YouTube video uploading soon Divide and Conquer Divide and conquer is a technique that splits a problem into smaller sub-problems of the same type , solves them (often using recursion ), and then combines the solutions to produce the final answer . This approach can significantly improve efficiency by reducing large input sizes into more manageable chunks , as seen in algorithms like quicksort . Divide and conquer algorithms include a binary search and a merge sort . The time complexity of divide and conquer algorithms is logarithmic - O(log n) - allowing complex problems to be solved much quicker than other algorithms . YouTube video uploading soon Abstraction Abstraction means removing unnecessary details to focus only on the most important features of a problem or system . It allows programmers to create simplified models that capture essential behaviour without becoming overwhelmed by irrelevant complexities . Abstraction enables generalisation , reusable designs and clearer reasoning about how components interact . In computational contexts, abstraction also highlights the difference between real-world systems and their simplified computational models . YouTube video uploading soon Backtracking Backtracking is used to explore possible solutions to a problem by building a partial solution and abandoning it as soon as it becomes clear it cannot succeed . It works by trying an option , checking whether it leads towards a valid solution , and backtracking to try a different path if a dead end is reached . This approach is used in constraint-based problems such as maze solving . While powerful , backtracking can be computationally expensive , so it often benefits from heuristics or pruning strategies . YouTube video uploading soon Data Mining Data mining is the process of extracting useful patterns , trends and relationships from large datasets . It enables organisations to identify hidden insights , predict behaviours and support data-driven decision-making , particularly in fields such as marketing , healthcare , finance and security . Data mining can lead to enhanced decision-making that can result in innovation , a competitive advantage against similar organisations and increased revenue . It can be used to identify anomalies or unused features . However, data mining doesn't explain the patterns it can identify and it requires powerful computers with a lot of processing power to handle huge amounts of data . YouTube video uploading soon Heuristics Heuristics are approximate problem-solving strategies that aim to produce good solutions quickly when exact , optimal methods are too slow or computationally impractical . They rely on rules of thumb to guide searches through very large solution spaces efficiently . Heuristics are widely used in artificial intelligence , optimisation tasks and complex search algorithms such as A* , where perfect accuracy is less important than fast , practical solutions . The trade-off is that heuristic methods are not guaranteed to produce the optimal answer , but they dramatically reduce processing time . YouTube video uploading soon Performance Modelling Performance modelling is the process of predicting how a system or algorithm will behave under different workloads , input sizes or hardware environments . It uses tools such as mathematical analysis , simulation and Big O notation to estimate required resources such as processing time or memory use . Performance modelling offers a cheaper , quicker and often safer way to test applications . For example, when a company beta tests an online game , it can trial the system with a smaller group of players and then apply performance modelling to predict how much server capacity will be needed when the game is fully released . YouTube video uploading soon Pipelining Pipelining is a technique in which different stages of a process are overlapped so that multiple instructions or operations are being processed simultaneously at different stages . In CPU architecture , for example, one instruction might be fetched while another is decoded and a third is executed , increasing overall throughput without increasing clock speed . Pipelining can also be used in algorithms or data-processing systems to prevent idle time in stages that operate independently . However, pipelining introduces complexity because dependencies or branch mispredictions may require a pipeline to be flushed - interrupting flow and reducing efficiency . YouTube video uploading soon Visualisation Visualisation supports the understanding of a problem by presenting information in a clearer and more accessible form than text alone . It is useful for explaining complex ideas or identifying patterns . Data can be shown visually through diagrams , graphs , trees , flowcharts or tables . The advantages of visualisation include helping to model , represent , analyse or summarise complex concepts . It allows information to be communicated more clearly and in a way that is easier to interpret . It can also provide different perspectives on how a problem might be solved . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Computational Methods: problem recognition, decomposition, divide and conquer, abstraction, backtracking, data mining, heuristics, performance modelling, pipelining, visualisation D id Y ou K now? Real-time location services like Google Maps use heuristics to guess travel times using heuristics such as estimated speeds , traffic history and shortcuts to make fast but approximate route suggestions . 2.1 - Programming Techniques A-Level Topics 3.1a-d - Algorithm Complexity

Learn about different input and output devices, RAM (random access memory) and ROM (read only memory) and storage devices, including solid state, magnetic and optical types. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 1.3 - Input, Output & Storage Specification: Computer Science H446 Watch on YouTube : Input & output devices Storage devices RAM & ROM Virtual storage This topic covers the internal and external devices required to input data into computer systems , output from them and store data for both temporary and long-term use . Input & Output Devices Input devices , such as a keyboard , mouse , microphone or sensor , allow data to be entered into a computer system for processing . Input can be manual (e.g. typing on a keyboard ) or automatic (e.g. a temperature sensor taking readings ). Output devices , such as monitors , printers and speakers , present the results of processing in a form understandable to humans . Input and output are not limited to text - they may also be visual , audio or tactile (e.g. braille displays or printed paper ). Storage Devices Secondary storage is non-volatile storage used to permanently hold programs and data when not in use by the CPU . There are three types : Magnetic storage uses magnetised patterns on a disk or tape (e.g. hard disk drives or magnetic tape ) to store large amounts of data for a low cost per gigabyte . Solid-state storage uses flash memory with no moving parts (e.g. SSDs and USB drives ), making it very fast , durable and portable . Because there are no moving parts, it is the fastest to access data . Optical storage uses lasers to read and write data as pits and lands on a disc surface (e.g. CDs, DVDs, Blu-ray). Discs are cheap to mass produce , but they are not durable , slow to access and have a low capacity . RAM & ROM Primary storage is low-capacity , internal storage that the CPU can directly access . There are two types: Random Access Memory (RAM ) is volatile storage that temporarily holds both programs and data currently in use , including the operating system . It can be read from and written to , but all contents are lost when the power is turned off . Read Only Memory (ROM ) is non-volatile storage that normally cannot be changed . The contents of ROM are saved when the power is turned off . ROM stores the BIOS and firmware , including the instructions needed to boot the computer when it is switched on . Virtual Storage Virtual storage is the separation of logical storage from physical storage , such as when data is stored remotely and accessed over a network instead of being kept locally . A common example is cloud storage , where data is held on remote servers and accessed via the internet . Benefits are that it is scalable , enables easy collaboration , provides automatic backup and saves local storage space . Drawbacks include that it relies on a stable internet connection , poses security risks and reduces user control over data . Q uesto's K ey T erms Input & Output Devices Secondary Storage: magnetic, solid state, optical, portability, capacity, cost (per GB), access speed, reliability, durability, power consumption Primary Storage: RAM, ROM, volatile, non-volatile Virtual Storage: cloud storage D id Y ou K now? The first commercial hard disk drive , the IBM 305 RAMAC (released in 1956 ), was the size of two fridges , weighed around a tonne , and stored just 5 MB of data - about the same as one .mp3 song . 1.2 - Types of Processor A-Level Topics 2.1 - Systems Software