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Test your understanding of string and number handling techniques in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python - Section 9 Practice Tasks Task One It is the national hockey championships and you need to write the program for the TV channel showing the live games. Let the user enter the name of the first country that is playing. Then let the user enter the name of the second country . Shorten country 1 to the first two letters . Shorten country 2 to the first two letters . Bonus: Display the teams in uppercase . Example solution: Welcome to the National Hockey Championships!!! Enter the first country: Montenegro Enter the second country: Kazakhstan Scoreboard: MO vs KA G Task Two In some places, the letter G is seen as an offensive letter. The government want you to create a program to count how many times the letter G appears in a sentence . Let the user input any sentence that they like. You need to count how many g’s there are. Then print the number of g’s there are. Example solution: Enter your sentence: good day! great golly gosh, got a good feeling! There were 7 instances of that awful letter! Task Three A pet shop has just ordered in a batch of new dog collars with name tags. However, there was a mistake with the order and the tags are too small to display names longer than 6 characters . You need to create a program that checks the user’s dog name can fit. Let the user enter their dog’s name . Calculate the length of their name. Use an if statement to see if it is greater than 6 characters . If it is then print – Sorry but our dog tags are too small to fit that. Otherwise print – Excellent, we will make this dog tag for you. Example solutions: Welcome to 'Dogs and Cats' Pet Shop! What is the name of your dog? Miles Excellent, we will make this dog tag for you! Welcome to 'Dogs and Cats' Pet Shop! What is the name of your dog? Sebastian Sorry, our dog tags are too small! Task Four It’s literacy week and the Head of English would like you to create a vowel checker program to ensure that year 7s are using plenty of vowels in their work. Let the user enter any sentence they like. For each letter in the sentence that they have just entered you need to use if statements to check if it is a vowel . You will need to use the OR operator between each statement to separate them. After the for loop you need to print the number of vowels they have used. Example solution: Enter your sentence: Put that thing back where it came from, or so help me! You used 14 vowels in your sentence. Task Five Remember the national hockey championships? Well, the company that hired you just fired you… Never mind though, a rival scoreboard company want to hire you right away. You need to let the user enter two countries like last time. But this time you don’t want to calculate the first two letters, you want to print the last three letters . Example solution: Welcome back to the National Hockey Championships!!! Enter the first country: Montenegro Enter the second country: Kazakhstan Scoreboard: GRO vs TAN Task Six Too many people are using inappropriate names on Instagram so they have decided to scrap the username and will give you a code instead. The code is the 2nd and 3rd letters of your first name , your favourite colour and then the middle two numbers of the year you were born . Let the user input their name, then their favourite colour and then the year they were born. Using their data, calculate their new Instagram name! Example solution: Welcome to Instagram What is your name? Matthew What is your favourite colour? red Which year were you born in? 1987 Your new profile name is: ATRED98 Task Seven Copy the text on the right and create a program that will split the text at each full stop. Count the number of names in the list. Print the longest name. Example solution: The list contains 20 names The longest name is alexandria annabelle.clara.damien.sarah.chloe.jacques.mohammed.steven.rishi.raymond.freya.timothy.claire.steve.alexandria.alice.matthew.harriet.michael.taylor ⬅ 9b - Number Handling 10a - Open & Write To Files ➡

Learn about the differences between wired and wireless networks. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 3.2a: Wired & Wireless Networks Exam Board: OCR Specification: J277 Watch on YouTube : Wired Networks Wireless Networks Encryption Wired Connections Wireless Connections Wireless connections, such as WiFi or Bluetooth , use no cables but require a wireless network interface card (WNIC ). Wireless connections generally have a slower speed and can be affected by the computer's distance from the wireless router as well as obstacles like walls or bad weather. Wired connections use physical cables , such as copper or fibre optic wires , and require a network interface card (NIC ) to connect to a network. These wired connections use a wired connection protocol - most commonly Ethernet . Restricted Movement Faster More Secure NIC Required Freedom of Movement Slower Less Secure WNIC Required Encryption Wireless connections are less secure and require encryption . Encryption is the process of scrambling data into an unreadable format so that attackers cannot understand it if intercepted during transmission. The original data (known as plaintext ) is converted to scrambled ciphertext using an encryption key . Only at the correct destination will the encryption key be used to convert the ciphertext back into plaintext to be understood by the receiving computer. Q uesto's Q uestions 3.2a - Wired & Wireless Networks: 1. Briefly compare wired and wireless networks in terms of movement , transmission speed , security and required hardware . You could answer this in the form of a table. [ 8 ] 3.1b - Network Hardware & Internet Theory Topics 3.2b - Protocols & Layers

Learn about the methods of digital protection including antimalware, firewalls and obfuscation. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 6.6 - Logical Protection Exam Board: OCR Specification: 2016 - Unit 2 Logical protection refers to using digital methods of security to protect computer systems and data. Usernames & Passwords ****** Anti-Malware Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system. Passwords should contain a mix of uppercase and lowercase letters , punctuation and numbers . Passwords should be of a substantial length (at least 8 characters) and should be regularly changed . Anti-virus software scans a system and removes viruses . If left to infect a system a virus could delete data or permit access to unauthorised users . Anti-spyware software removes spyware on an infected system so hackers cannot view personal data or monitor users. Organisations should install and regularly update anti-virus and anti-spyware programs. Firewall Encryption Firewalls prevent unauthorised access to or from a network . Firewalls filter data packets and block anything that is identified as harmful to the computer system or network. Firewalls can also be used to block access to specific websites and programs. A firewall can be in the form of a physical device which is connected to the network, or software installed on a computer system. Encryption is the conversion of data ( plaintext ) into an unreadable format ( ciphertext ) so it cannot be understood if intercepted . Encrypted data can only be understood by an authorised system with a decryption key . There are two types of encryption . Encryption at rest is when data is encrypted while it is being stored on a system or storage drive. Encryption in transit is to secure the data as it being transferred between systems on a network. Tiered Levels of Access Obfuscation ?????? The purpose of tiered levels of access is to grant different types of permission to certain users. Managing levels of file access ensures that only authorised people can access and change certain files . There are different levels of file access : No access Read-only - Allows a user to view but not edit. Read/write - Allows a user to view and edit. Obfuscation is when data is deliberately changed to be unreadable to humans but still understandable by computers . Program code might be obfuscated to stop rival programmers from viewing and stealing it if they were able to access it. Specialist software can be used to obfuscate data and convert it back into a human-readable format. Q uesto's Q uestions 6.6 - Logical Protection: 1a. Describe why usernames and strong passwords are necessary. [2 ] 1b. State 3 rules for choosing a strong password . [3 ] 2. Describe the purpose of anti-virus and anti-spyware software. [4 ] 3. Describe the roles of a firewall . [4 ] 4. Explain what encryption is. What are the two types? [4 ] 5. Why would an organisation use tiered levels of access ? What are the 3 levels of file access ? [5 ] 6. What is obfuscation ? State a scenario in which it would be used. [3 ] 6.5 - Physical Protection Topic List

Learn about utility software including antivirus, firewall, compression, disk partitioners, defragmenters, backup and file managers. Based on the 2020 Eduqas (WJEC) GCSE specification. 6.2: Utility Software Exam Board: Eduqas / WJEC Specification: 2020 + What is utility software? Utility software are dedicated programs used for the maintenance and organisation of a computer system. Antivirus Antivirus software is used to locate and delete viruses on a computer system. The antivirus scans each file on the computer and compares it against a database of known viruses . Files with similar features to viruses in the database are identified and deleted . Firewall A firewall manages incoming and outgoing network traffic . Each data packet is processed to check whether it should be given access to the network by examining the source and destination address . Unexpected data packets will be filtered out and not accepted to the network. Disk Defragmenter As files are edited over time they will become fragmented - this is when the file is split into parts that are stored in different locations on the hard disk drive . Files that are fragmented take longer to load and read because of the distance between the fragments of the file. Defragmentation software is used to rearrange the file on the hard disk drive so that all parts are together again in order. Defragmentation improves the speed of accessing data on the hard disk drive. Backup Software System backup copies data onto a separate storage device in case the original information is lost or corrupted . Backups should be saved regularly and stored in a different location to the rest of the data. Magnetic tape is a common backup medium. A typical backup policy is one known as 'grandfather - father - son' which uses three different backups at a time. Disk Compression Compression is the process of decreasing the size of a file . Disk compression is a utility tool that automatically compresses files when saved so that more data can be stored on the hard disk drive. When a file is to be opened, the program is automatically decompressed . Disk compression increases the amount of space on a hard disk drive but it takes longer to open and close files . Disk Checker This utility is used to scan a hard drive for any corrupted data . The corrupted data is deleted to speed up reading from and writing to the hard drive. More advanced disk checkers are used to scan for bad sectors . A bad sector is a permanently damaged section of the hard drive which can no longer be used and must be skipped over. Disk Formatter Disk Partition Editor This utility tool prepares a storage device such as the hard disk drive to be used by removing the current data and creating a file system . A file system manages how data is stored and accessed . Other devices like a USB stick may need to be formatted before they can be used for the first time . Within memory, partitions are segments of data that have been grouped together logically on the hard disk drive . A disk partition editor allows a user to view and modify these memory partitions . Options include creating, editing and deleting partitions. Clipboard Manager The clipboard is a temporary storage space for copied data. For example, a large amount of text can be copied and stored on the clipboard to be pasted into another document, even when the original file has been closed . The clipboard manager adds more functionality to the clipboard to allow multiple pieces of data to be copied, cut and pasted . System Profiles A system profiler displays detailed information about the applications on a computer system, as well as data about any attached hardware devices . Information is provided and updated in real-time about the performance of software and internal components such as the CPU . Data Recovery Data recovery tools allow deleted, corrupted or otherwise inaccessible data to be returned to a usable state . The data loss may have been caused by physical damage to a drive, corrupt memory partitions or accidental deletion . Most data is not permanently removed when it is deleted so data recovery software can often be used to reaccess files . Revision Control Revision control software manages previous versions of an application so that if an error occurs the program can be returned to a previous state . This is also called version control software and can be used to manage and monitor changes made to files over time. Archiver Archiving is the process of storing important data that is not currently required . It must not be deleted but it shouldn't take up valuable storage space either. An archiver compresses multiple files using lossless compression into one folder . This archived folder can be stored on a computer system or transferred to a storage device and won't take up much space . Cryptographic Utilities A cryptographic utility is used to encrypt data so that it cannot be understood if intercepted . Encryption is commonly for data in transit - being sent between devices . Cryptographic software can also encrypt data at rest - when stored on a hard disk drive for example - so that hackers would be unable to use the data . File Manager This utility tool provides an interface to the user for accessing, editing and moving files and folders on the system. Programs will be displayed in a hierarchical ( ordered ) structure with icons representing the application logo or file type. Files can be ordered in alphabetical, chronological or other orders and the manager provides an abstracted visualisation of where the data is stored. Q uesto's Q uestions 6.2 - Utility Software: 1. What is meant by utility software ? [1 ] 2. Describe each type of utility software : a. Antivirus b . Firewall c . Disk Defragmenter d . Backup Software e . Disk Compression f . Disk Checker g . Disk Formatter h . Disk Partition Editor i . Clipboard Manager j . System Profiles k . Data Recovery l . Revision Control m . Archiver n . Cryptographic Utilities o . File Manager [2 ] 6.1 - Operating Systems Theory Topics 7.1 - Language Levels

Learn about common prevention methods of minimising cyber security risks including anti0malware, firewalls and penetration testing. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 4.2: Preventing Vulnerabilities Exam Board: OCR Specification: J277 Watch on YouTube : Preventing Vulnerabilities Penetration Tests Penetration tests are carried out as part of ethical hacking. The purpose of a penetration test is to review the system's security to find any risks or weaknesses and to fix them . Internal tests are to see how much damage could be done by somebody within the company with a registered account. External tests are for white hat hackers to try and infiltrate a system from outside the company . Anti-Malware Software Anti-malware software is used to locate and delete malware, like viruses, on a computer system. The software scans each file on the computer and compares it against a database of known malware . Files with similar features to malware in the database are identified and deleted . There are thousands of known malware, but new forms are created each day by attackers, so anti-malware software must be regularly updated to keep systems secure. Other roles of anti-malware software: Checking all incoming and outgoing emails and their attachments . Checking files as they are downloaded . Scanning the hard drive for viruses and deleting them . Firewall A firewall manages incoming and outgoing network traffic . Each data packet is processed to check whether it should be given access to the network by examining the source and destination address . Unexpected data packets will be filtered out and not accepted to the network. Other roles of a firewall include: Blocking access to insecure / malicious web sites . Blocking certain programs from accessing the internet . Blocking unexpected / unauthorised downloads . Preventing specific users on a network accessing certain files . Secure Passwords ******** Usernames must be matched with a secure password to minimise the chances of unauthorised users accessing a system. Passwords should contain a mix of uppercase and lowercase letters , punctuation and numbers . Passwords should be of a substantial length (at least 8 characters) and should be regularly changed . User Access Levels Access levels are used to only allow certain users to access and edit particular files. ' Read-Only ' access is when a user can only view a file and is not allowed to change any data . For example, a teacher might set homework instructions as read-only for students to view. ' Read and Write ' access allows a user to read and edit the data in a file. For example, a teacher might set an online workbook as read and write access for students to fill in. It is important to set access levels so that only authorised users can view and change data. The more users who have access to a file, the more likely it is to be compromised. Certain users may also have no access to a file - when they can't view or edit it. Encryption Encryption is the process of scrambling data into an unreadable format so that attackers cannot understand it if intercepted during transmission. The original data (known as plaintext ) is converted to scrambled ciphertext using an encryption key . Only at the correct destination will the encryption key be used to convert the ciphertext back into plaintext to be understood by the receiving computer. Physical Security A lock can be used to prevent access to server rooms or locations that store confidential data . Only authorised personnel with a matching key will have access. Biometric devices require the input of a human characteristic (such a fingerprint , iris or voice ). The biometric data is checked against previously inputted data in a database. Only a match will allow access to the user. Other forms of physical security include keycards , security staff , CCTV cameras and alarms . Q uesto's Q uestions 4.2 - Preventing Vulnerabilities: 1. Describe the purpose of penetration tests . [2 ] 2. Describe the purpose of anti-malware software and its different roles . [ 4 ] 3. Describe the purpose of a firewall and its different roles . [ 4 ] 4. State three rules for choosing a strong password . [ 3 ] 5. Describe the three types of access level . [6 ] 6a. Describe the purpose of encryption . [ 2 ] 6b. Explain how encryption works, using the terms plaintext , key and ciphertext . [ 4 ] 4.1 - Security Threats Theory Topics 5.1 - Operating Systems

Learn about the tools of an integrated development environment (IDE) including the editor, debugger, library, trace, memory inspector and error diagnostics. Based on the 2020 Eduqas (WJEC) GCSE specification. 9.1: IDE Tools Exam Board: Eduqas / WJEC Specification: 2020 + An IDE (Integrated Development Environment ) provides programmers with the following facilities (tools ) to help create programs : Editor The editor is software that allows a programmer to enter and edit source code . Editor features may include: Automatic formatting (e.g. automatic indentation). Automatic line numbering (this helps to identify exactly where an error has occurred). Automatic colour coding (e.g. Python turns loop commands orange and print commands purple). Statement completion (e.g. offering to auto-complete a command as the user is typing.) Libraries A library is a collection of commonly used functions and subprograms that can be linked to a program . For example, Python can import functions from its code library including random or time commands). Libraries must be linked to the main program using a linker . Linker Links together pre-compiled code from software libraries . For example, the import random command in Python links to the random library. Loader Pre-compiled code is loaded into RAM to be executed. Code Optimisation The code is optimised so it is fast , efficient and uses as little of the computer's resources as possible. Debugger Identifies errors in the code with the exact line of the error to help fix the problem . Break point The programmer selects a specific line and the program is paused once it reaches it. Variable values at that point are shown . Variable Watch cost Displays the current value of a selected variable . A variable can be watched line-by-line to see how the value changes . Trace Memory Inspector Logs the values of variables and outputs of the program a s the code is executed line by line . Displays the contents of a section of memory and how it is being used by the program . Error Diagnostics Displays information about an error when it occurs, such as the line it occurred on and the error type (e.g. syntax or runtime). This helps the programmer to fix the error . Specific errors can be detected such as a syntax error . See 10.3 . Compilers & Interpreters Both tools convert the source code written by a programmer into machine code to be executed by the CPU. A compiler converts the entire source code into executable machine code at once . After compilation, the program can be run again without having to recompile each time. An interpreter converts source code into machine code line by line . An interpreter must reinterpret the code each time the program is required to run . See 10.1 for both tools. Subroutines & Functions A subroutine is a section of code that can be re-used several times in the same program. There are two types of subroutines: A procedure just executes commands , such as printing something a certain number of times. A function can receive data from the main program (called a parameter ) and return a value upon completion. Subroutines (procedures and functions) are designed to be repeated and have three key benefits: Subroutines make programs easier to read and design . They reduce the duplication of code . Makes it is easier to debug a program. Q uesto's Q uestions 9.1 - IDE Tools: 1. Describe the purpose of each type of IDE facility : a. Editor b. Interpreter c. Compiler d. Linker e. Loader f. Debugger g. Break point h. Variable Watch i. Trace j. Memory Inspector k. Error Diagnostics [ 2 each ] 8.5 - Validation & Verification Theory Topics 10.1 - Translators

Learn about the three main types of memory in a computer system - RAM (Random Access Memory), ROM (Read Only Memory) and Cache Memory. Memory What is memory? Memory is where a computer stores information , instructions and data so it can use them quickly when needed . There are three main types of memory : RAM Random Access Memory ROM Read Only Memory Cache Memory What is Random Access Memory? RAM is volatile (this means that when power is lost, the data is deleted ). Every program that is being run by the computer (such as Google Chrome, Spotify or Microsoft Word) is stored in RAM . RAM is made up of a large number of storage locations , and each is identified with a unique address . What is Read Only Memory? ROM is non-volatile (this means that data is saved, even when the power is off ). The start-up instructions (for when a computer is switched on ) are stored in ROM . ROM is read-only, which means that it cannot be edited or changed . What is Cache Memory? Cache memory is fast to access because it is built into the CPU (or very close to it) . Cache memory stores data that needs to be accessed very frequently . Cache memory is very expensive , so there is only a small amount in most computers. How can a computer run faster? There are many reasons why a computer may be running slowly . Here are some methods related to memory that can help speed up a system : Close unnecessary programs to free up RAM so it doesn't run out of memory space . Add more RAM so the computer can run more programs at once without slowing down . Increase the cache size so the CPU can access important data more quickly . KS3 Home Note: Only larger systems like desktop computers can have their components easily upgraded and replaced.

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 two important expansion cards that can be connected to the motherboard - graphics cards and sound cards - and how they work. Expansion Cards PCI slots What are expansion cards? Expansion cards are additional components that you plug into the motherboard’s expansion slots to add or enhance features . The slots are called PCI (on older computers ) or PCIe (on newer models ). Common types are graphics cards (video ), sound cards (audio ), network cards (internet ) and capture cards (streaming ). Graphics Card A graphics card processes images , videos and 3D graphics so they look smooth and realistic . It is used for gaming , video editing , 3D modelling and Virtual Reality (VR ). It has its own processor - the Graphics Processing Unit (GPU ) - and dedicated memory (VRAM ), so it doesn’t overload the CPU or RAM . Modern graphics cards can also handle tasks like artificial intelligence (AI ) and bitcoin mining . Graphics cards usually have a cooling system, like a fan , so it doesn't overheat. The graphics processing unit ( GPU ) is a chip that renders images and video. The graphics card has ports such as HDMI or DisplayPort to connect monitors or TVs. The PCIe connector allows the graphics card to slot onto the motherboard. Sound Card The DAC ( Digital-to-Analogue Converter ) converts digital data (1s and 0s) from the computer into analogue sound waves for speakers/headphones. The ADC ( Analogue-to-Digital Converter ) converts analogue input (like voice from a microphone) into digital data the computer understands. Jacks are small round sockets where you plug in audio devices like headphones, microphones, or speakers. The PCIe connector allows the sound card to slot onto the motherboard. A sound card improves the quality of audio input/output compared to the motherboard’s built-in sound . They are not needed by most users , because of the motherboard's built-in sound , but they are used by music production , gaming or professional audio work . It can support surround sound systems , high-quality microphones , and musical instruments using jacks (audio ports ). Integrated cards Built directly into the motherboard . Cheaper , uses less power and is good enough for basic tasks (e.g. web browsing , watching videos and office work ). Shares the computer’s RAM and processor (CPU ) instead of having its own . An example is integrated graphics on a laptop for browsing and schoolwork . Dedicated cards These are separate expansion cards (e.g. graphics card or sound card ) to connect to the motherboard 's PCIe slots . They usually have their own processor and memory (e.g. GPU & VRAM for graphics ). Much more powerful , ideal for gaming , video editing , 3D design or professional audio . Uses more power and costs more . KS3 Home

Learn about the two types of language levels - high level languages and low level languages , as well as the use of interpreters and compilers. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 5.1: Languages & Translators Exam Board: OCR Specification: J277 Watch on YouTube : High-Level & Low-Level Languages Translators (Compiler & Interpreter) There are two types of programming languages used within computer systems: High-Level Languages Why do programmers use high-level languages? H igh-level programming languages use code written in a way that is similar to a natural human language , such as English, making it easier to understand and use the language. Using high-level languages leads to fewer errors and allows for more powerful and complex commands compared to low-level languages. However, a high-level language must be translated into machine code (binary) before it can be run, as high-level languages cannot be executed directly by the CPU . Popular high-level languages: PYT HON C++ Ja v a Visual Basic Low-Level Languages Low-level languages do not closely resemble a natural human language , making it harder for humans to understand and write in. Low-level languages are used when a program must be executed quickly or when programmers need to write code that interacts directly with the hardware , such as device drivers. There are two types of low-level language : Machine Code This is the pure binary code that computers can directly process and execute . It is extremely tedious and difficult for humans to understand and write machine code. However, machine code can be used when a programmer needs to perform a very specific command that can't be done in a high-level language. Machine code will be executed faster than high-level programs because it is already in a format the CPU can execute and does not need to be translated . 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0101 0100 1010 1010 1010 1010 1111 1110 0010 1001 0100 1001 0010 0111 0111 0101 0011 1010 1000 0101 0110 0111 0000 1010 1010 0011 1101 1001 0010 1101 0010 0100 1001 0011 1010 1001 0101 0101 0010 0101 0111 0101 0101 1000 1011 0111 Assembly Language Assembly language uses specialised command mnemonics to perform actions . See the Assembly Language section in the programming tab for a list of mnemonics such as INP , OUT and HLT . Assembly language is preferred by many programmers over machine code because it is easier to understand and spot errors . It is faster to execute than high-level languages and, like machine code, can be used to directly control the CPU . INP STA Number1 OUT HLT Number1 DAT Translators A translator changes (translates) a program written in one language into another language (usually machine code ). There are two main types of translator : Interpreter An interpreter converts high-level language one line at a time into machine code and executes it. Compiler A compiler converts high-level language into machine code for execution at a later time. The entire program is converted at once . PYT HON PYT HON 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 Interpreters vs Compilers Interpreter Compiler Execution Method: An interpreter translates source code (high level code) into machine code one line at a time . Execution Speed: An interpreter is slower than a compiler because the code must be reinterpreted each time the program is run. Complexity: Interpreters are smaller, simpler programs . Error Reporting: In error reporting, the interpreter would encounter the errors and report it to the user immediately and stops the program from running. Repetition: Interpreted programs can be edited and run without translating the whole program . Interpreters must reinterpret the program every time it is run. Execution Method: A compiler translates all the source code (high level code) into machine code in one go . A compiler produces an executable file that will run on other machines without the compiler needing to be installed. Execution Speed: Compilers can produce much more efficient code than interpreters making the compiled programs run faster . Complexity: Compilers tend to be large complex programs . Error Reporting: The compiler would analyse the entire program , taking note of where errors have occurred and record them in an error file . Repetition: Compilation requires analysis and the generation of the code only once , whereas interpreters must re-interpret each time. However, compiled programs have to be re-compiled after any changes have been made. x1 ∞ x1 Q uesto's Q uestions 5.1 - Languages & Translators: 1a. Describe three reasons why programmers use high-level languages . [ 3 ] 1b. Explain one limitation of using high-level languages . [2 ] 2a. Describe a key difference between low-level languages and high-level languages . [ 2 ] 2b. Describe when a low-level language would be used instead of a high-level language . [2 ] 2c. Describe an advantage and a disadvantage of writing directly in machine code . [2 ] 2d. Describe what assembly language is. Give one benefit to using assembly language instead of machine code and one benefit to using it instead of a high-level language . [3 ] 3. Compare high-level and low-level languages by stating which is: a. Easier to understand [ 1 ] b. Requiring translation [ 1 ] c. Quicker to execute [ 1 ] 4. Compare interpreters and compilers for each of the following features : a. Execution Method b. Execution Speed c. Complexity d. Error Reporting e. Repetition [ 10 total ] 4.1 - Boolean Logic Theory Topics 5.2 - IDE

Learn about protocols including FTP, HTTP, POP, SMTP, SNMP, TCP, UDP, ICMP, IP and the TCP/IP stack. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 3.2 - Protocols Watch on YouTube : Protocols TCP/IP Stack You need to know the role and uses of specific common protocols (FTP , HTTP , POP , SMTP , SNMP , TCP , UDP , ICMP , IP ). You also need to understand the structure , content and use of the 4-layer TCP/IP stack . What You Need to Know Common Protocols ? YouTube video uploading soon TCP/IP Stack ? YouTube video uploading soon Q uesto's Q uestions 3.2 - Protocols: 1. What? [2 ] 2. What? [1 ] 3. What? [1 ] 4. What? [1 ] ? D id Y ou K now? 3.1 - APIs Topic List 4.1 - Security Considerations

Learn about pseudocode, procedural programming, big O notation (constant, linear, polynomial (quadratic), exponential, linearithmic and logartihmic) and the complexity of different data structure, sorting and searching algorithms. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 3.1a - 3.1d - Algorithm Complexity Watch on YouTube : Pseudocode Procedural programming Big O notation Algorithm complexity Pseudocode Pseudocode is a simplified , language-independent way of writing algorithms that looks like programming but uses plain English to describe the steps clearly without worrying about exact syntax . The OCR A-Level Computer Science course uses a form of pseudocode unique to the exam board called 'OCR exam reference language ' that all code in exams will be written in . OCR exam reference language uses closing commands such as endif for an if statement and endwhile for a while loop . It also uses the word then instead of a colon like in Python . YouTube video uploading soon Procedural Language A procedural language , such as Python or Java , is a programming language that structures programs as sequences of step-by-step instructions grouped into procedures or functions . It focuses on breaking tasks into smaller , reusable blocks of code that operate on data , making programs easier to write , understand and maintain . This topic is in both Paper 1 and Paper 2 . YouTube video uploading soon Big O Notation O(n) Big O Notation is a way of describing how the time complexity (how long an algorithm takes ) and space complexity (how much memory it uses ) grows as the size of the input increases . This allows algorithms to be compared in terms of efficiency , using the letter n to refer to the size of the input . Complexity types: Constant - O(1) - The algorithm’s time or space stays the same no matter how large the input is . Linear - O(n) - The time or memory grows directly in proportion to the size of the input . Polynomial - O(n²) - The growth increases in proportion to the square of the input , often seen in algorithms with nested loops . Exponential - O(2ⁿ) - The time or memory doubles with each additional input element , becoming extremely slow very quickly . Logarithmic - O(log n) - The algorithm’s time grows very slowly as the input size increases , often achieved by repeatedly halving the data . Linearithmic - O(n log n) - A combination of linear and logarithmic behaviour, common in efficient sorting algorithms like merge sort . YouTube video uploading soon Algorithm Complexity Best-case , average-case and worst-case complexity describe how an algorithm performs under different input conditions . Best-case complexity is the time or space required when the algorithm meets the most favourable input , allowing it to finish as quickly or efficiently as possible . Average-case complexity represents the expected performance across typical or random inputs , giving a realistic view of how the algorithm behaves in normal use . Worst-case complexity is the maximum time or space the algorithm could ever require , used to guarantee performance even in the least favourable situation . Sorting and searching algorithms often have different case complexities for time and space . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Pseudocode Procedural Language: input, output, comments, variables, casting, count-controlled iteration, condition-controlled iteration, logical operators, selection, string handling, subroutines, arrays, files Big O Notation: time complexity, space complexity, constant, linear, polynomial, exponential, logarithmic, linearithmic, best-case, average-case, worst-case D id Y ou K now? Minecraft doesn’t load the entire world at once ; instead, it divides the world into chunks and only generates or loads the chunks near the player . Finding , saving and retrieving these chunks uses data structures like trees and hash maps , which allow the game to look up a chunk in about O(log n) or even O(1) time , minimising lag even in large worlds . 2.2 - Computational Methods A-Level Topics 3.1e - Data Structure Algorithms