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Navigate between all Unit 1 (Fundamentals of IT) topics in the OCR Cambridge Technicals Level 3 IT 2016 specification. OCR Cambridge Technicals IT Level 3 Unit 1: Fundamentals of IT These pages are based on content from the OCR Cambridge Technicals 2016 Level 3 IT specification . This website is in no way affiliated with OCR . This qualification stopped in July 2025. The pages on the site will remain for at least two years. LO1 (Computer Hardware ) 1.1 - Computer Hardware 1.2 - Computer Components 1.3 - Types of Computer System 1.4 - Connectivity 1.5 - Communication Hardware 1.6 - Hardware Troubleshooting 1.7 - Units of Measurement 1.8 & 1.9 - Number Systems & Conversion LO2 (Computer Software ) 2.1 - Types of Software 2.2 - Applications Software 2.3 - Utility Software 2.4 - Operating Systems 2.5 - Communication Methods 2.6 - Software Troubleshooting 2.7 - Protocols LO3 (Networks & Systems ) 3.1 - Server Types 3.2 - Virtualisation 3.3 - Network Characteristics 3.4 - Connection Methods 3.5 - Business Systems LO4 ( Employability & Communication ) 4.1 - Communication Skills 4.2 - Communication Technology 4.3 - Personal Attributes 4.4 - Ready for Work 4.5 - Job Roles 4.6 & 4.7 - Bodies & Certification LO5 (Issues & Security ) 5.1 - Ethical Issues 5.2 - Operational Issues 5.3 - Threats 5.4 - Physical Security 5.5 - Digital Security 5.6 - Data & System Disposal

Learn about project planning tools such as the Arrow diagram, Critical Path Analysis (CPA)/Critical Path Method (CPM), Flowcharts, Gantt charts, PERT charts and SWOT (Strengths / Weaknesses / Opportunities / Threats) analysis. Based on Unit F160 (Fundamentals of Application Development) for the OCR Cambridge Advanced National in Computing (H029 / H129) (AAQ - Alternative Academic Qualification). Qualification: Cambridge Advanced National in Computing (AAQ) Unit: F160: Fundamentals of Application Development Certificate: Computing: Application Development (H029 / H129) 3.2 - Project Planning Tools Watch on YouTube : Project planning tools Arrow diagram Critical path analysis Flowcharts Gantt charts PERT charts SWOT analysis Project Planning Tools Project planning tools help to visualise the project by clearly showing tasks , timelines and dependencies . They also break down complex work into smaller , manageable steps and can be used to track progress and identify delays . Each tool suits different project needs and has its own advantages and disadvantages . Choosing the right tool makes planning more accurate , efficient and successful . Arrow Diagram The arrow diagram method is a project planning tool that represents tasks as arrows connected in sequence to show their order and dependencies . It helps identify the critical path . This is the longest sequence of dependent tasks that determines the project’s minimum completion time . This method is useful for visualising task relationships , spotting bottlenecks and showing the order of activities . Critical Path Analysis Critical path analysis ( CPA ), also known as the critical path method ( CPM ), is a project planning tool used to identify the critical path . This is the sequence of tasks that determines the shortest possible project duration . It highlights tasks that cannot be delayed without affecting the overall timeline . Critical path analysis helps prioritise resources , manage dependencies and minimise project delays . Flowcharts A flowchart is a diagram that represents a process or workflow using standard symbols and arrows to show the sequence of steps . It helps visualise decision points and actions and clearly highlights the flow of information or tasks . Flowcharts make complex processes easier to understand , communicate ideas to clients and troubleshoot potential problems . Gantt Charts A Gantt chart is a visual project management tool that displays tasks along a timeline , showing their start and end dates . It helps track task dependencies , overlaps and progress at a glance . Gantt charts are useful for coordinating work , meeting deadlines and ensuring all project stages are completed in order . PERT Charts A PERT ( program evaluation and review technique ) chart is a project planning tool that maps tasks , their dependencies and timelines in a network diagram . It uses three time estimates ( optimistic , most likely and pessimistic ) to calculate expected completion times for each task . PERT charts are especially useful for scheduling complex projects and identifying the critical path to meet deadlines . SWOT Analysis SWOT analysis is a strategic planning tool used to identify a project’s strengths , weaknesses , opportunities and threats . Strengths and weaknesses focus on internal factors ( controllable by the organisation ), while opportunities and threats look at external influences ( outside of the organisation's control ). It helps guide decision-making by highlighting advantages , weaknesses to address and potential risks or openings in the wider environment . Q uesto's Q uestions 3.2 - Project Planning Tools: 1. Define the term 'critical path ' and explain why it is calculated . [3 ] 2. Explain the S , W , O and T in SWOT analysis (not just what they stand for). [4 ] 3. Choose three project planning tools and describe the advantages and disadvantages of each . [ 12 ] Henry Gantt , an American engineer , created the Gantt chart in the 1910s . It has been used as a planning tool in many major projects , including building the Hoover Dam . D id Y ou K now? 3.1 - Planning Projects Topic List 4.1 - Gathering Client Requirements

Learn how to handle errors in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python 12 - Error Handling Errors When an error occurs in Python, you may see a chunk of red text like this. This is very useful when creating programs as it tells us the exact line of the error (10), and its type (NameError). However, a completed program should have code in place for when an unexpected error occurs – we call this exception handling . General Exception In this example, Python will attempt to run the code indented beneath try . If there are no errors then the code will stop just before except . If an error does occur then the Exception code will be run . If we enter a correct value then the program will execute normally: But if an error occurs (such as writing a string when an integer is expected) then the Exception code will run : You can add the else command to your code that will execute only if there are no errors : If a valid number is entered then the else code will be printed: If a code generating an error is entered then the except code will be printed: Practice Task 1 Create a program that asks the user to input their age. Don't forget to use the int command. Use try and except to print a message if a number is not inputted. Example solution: Specific Exceptions The Exception command used in the section above is for any general error that occurs. You can also use specific except commands for a variety of errors. Below is a program with two different specific exception commands for one try statement: If a Value Error occurs, such as when the wrong data type is entered , then related code will be printed: Or if the user tries to divide by zero then a Zero Division Error will be triggered which prints a relevant response: Other types of exception can be found here . Practice Task 2 Create a program that asks the user to input a number and then divides this value by 999. Create a Value Error and Zero Division Error exception and include an appropriate message in both. Example solution for Zero Division: ⬅ 11 - Graphical User Interfac e Extended Task 1 (Pork Pies) ➡

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.

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

Navigate between all Unit 2 (Global Information) topics in the OCR Cambridge Technicals Level 3 IT 2016 specification. OCR Cambridge Technicals IT Level 3 Unit 2: Global Information These pages are based on content from the OCR Cambridge Technicals 2016 Level 3 IT specification . This website is in no way affiliated with OCR . This qualification stopped in July 2025. The pages on the site will remain for at least two years. LO1 (Devices & The Internet ) 1.1 - Holders of Information 1.2 - Storage Media 1.3 - Access & Storage Devices 1.4 - Internet Connections 1.5 - WWW Technologies 1.6 - Information Formats 1.7 & 1.8 - Internet Pros & Cons LO2 (Information Styles & Quality ) 2.1 - Information Styles 2.2 - Information Classification 2.3 - Quality of Information 2.4 - Information Management LO3 (Categories & Analysis ) 3.1 - Data vs. Information 3.2 & 3.3 - Information Categories 3.4 - Stages of Data Analysis 3.5 - Data Analysis Tools 3.6 - Information Systems LO4 (Legislation ) 4.1 - UK Legislation 4.2 - Global Legislation 4.3 - Green IT LO5 (Flow of Information ) 5.1 - Data Types & Sources 5.2 - Data Flow Diagrams LO6 (Security & Protection ) 6.1 - Security Principles 6.2 - Risks 6.3 - Impacts 6.4 - Protection Measures 6.5 - Physical Protection 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 operating systems, memory management (segmentation and paging), scheduling, interrupts, the BIOS, device drivers and virtual machines Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 2.1 - Systems Software Specification: Computer Science H446 Watch on YouTube : Operating systems functions Paging & segmentation Interrupts Scheduling algorithms Types of operating system BIOS Device drivers Virtual machines This topic looks at how the operating system manages the resources of a computer system . It also includes programs related to the operating system , such as the BIOS , device drivers and virtual machines . Operating Systems The operating system performs essential functions to keep a computer running efficiently . It provides a user interface , such as a command line or graphical user interface ( GUI ), and ensures system security by managing access rights and protecting files . The OS manages hardware , coordinating devices like the CPU , printers and hard drives and provides built-in utilities for tasks such as file management and disk defragmentation . It acts as a platform for software , allowing applications to be installed and run . The OS also schedules jobs , handles interrupts from devices, and manages memory , ensuring each process has the resources it needs without conflicts. Paging & Segmentation Paging is a memory management method that splits memory into equal-sized blocks called pages . This makes memory use more efficient as programs don’t need to be stored in one continuous block but unused space may be wasted inside a page . Segmentation divides memory into segments of different sizes based on program structure . This makes it easier to organise parts of a program , but because segments are different sizes , it can leave small unused gaps in memory that can’t be easily filled by other data. Interrupts An interrupt is a signal that tells the CPU to pause its current task and respond to something more urgent . Interrupts can come from hardware , such as a keyboard press , or from software , such as an error . When an interrupt occurs , the CPU saves its current state by placing current register values into a stack . The CPU runs an interrupt service routine ( ISR ) to handle the interrupt event . After the ISR finishes , the CPU restores its state by popping values from the stack and continues the original program . Scheduling Scheduling algorithms are used by the CPU to decide the order in which processes are executed . They aim to manage CPU time efficiently and ensure all programs get a fair share of resources . Common scheduling algorithms include: First-Come First-Served : Processes are executed in the order they arrive to the CPU . Round Robin : Each process gets a fixed time slice in turn , cycling through all processes. Shortest Job First / Shortest Time Remaining : These methods identify the process with the shortest estimated runtime to be executed first . Multi-Level Feedback Queue : Uses multiple queues with different priority levels . Processes can be moved between queues to avoid starvation . Types of OS Different types of operating systems exist depending on the computer system and purpose : Multitasking OS : Allows a single computer to run multiple programs at the same time by quickly switching between them. Multi-user OS : Lets multiple users access the computer and its resources simultaneously , often via a network . Distributed OS : Manages a group of networked computers as a single system , sharing resources and tasks . Embedded OS : Designed for devices with specific functions , like microwaves or smart TVs , often with limited resources . Real-time OS : Provides immediate processing and responses for time-critical tasks , used in systems like medical devices or industrial robots . The BIOS The BIOS (Basic Input/Output System ) is firmware stored in ROM that helps the computer start up and manage initial communication between hardware and the operating system . During the start-up sequence , the BIOS first checks that essential hardware (e.g. the CPU and RAM ) is present and working correctly by running a Power-On Self Test (POST ). Signals are transmitted to all connected components . The BIOS then runs the bootstrap program to locate and load the operating system from a connected storage device into RAM . Once the OS is loaded , control is handed over to it, allowing the computer to become fully operational . Device Drivers A device driver is software that allows the operating system to communicate with hardware devices such as printers , graphics cards or keyboards . Hardware and the OS speak different ' languages ', so the driver translates OS instructions into commands the device can understand and vice versa. They are needed because, without drivers , the OS wouldn’t know how to control the hardware or use its features properly. Drivers also allow devices to work with different versions of an operating system and enable updates that improve performance or fix bugs . Virtual Machines A virtual machine is a software-based computer that runs an operating system and applications like a real computer , using part of the host computer’s hardware . It is isolated from the main system , so it can operate safely without affecting the host . Virtual machines are commonly used for testing software , running multiple operating systems and safely handling untrusted files . They provide flexibility , efficient hardware use and a secure environment for experimentation . Q uesto's K ey T erms Operating Systems: user interface, file management, user management Memory Management: paging, segmentation, virtual memory Interrupts: interrupt, interrupt service routine, stack Scheduling Algorithms: first come first serve, round robin, shortest job first, shortest time remaining, multilevel feedback queue Types of Operating System: multitasking, multi-user, distributed, embedded, real-time BIOS: ROM - power-on self-test (POST) Device Drivers: device driver Virtual Machines: virtual machine, thin clients, servers D id Y ou K now? New versions of the Android operating system used to be named alphabetically after sweet treats , from Cupcake , Donut and Eclair to Nougat , Oreo and Pie - the final named update in 2019 . 1.3 - Input, Output & Storage A-Level Topics 2.2 - Applications Generation

Learn how to create and use lists in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 8a - Using Lists Lists A list is a temporary data structure . Any changes made to the list while the program is running will not be saved the next time it is run . Data can be added to and removed from lists so they can change in size (unlike an array which is fixed and not used in Python). It is important to note that each data element in a list has an index so that it can be specifically referenced (to delete it for example) and that indexes start at 0 . A list of the rainbow colours in order would start at 0 like this: Creating & Printing Lists Lists use square brackets in Python. Separate list items with commas . Strings must use speech marks and integers do not use speech marks. people = [ "Alan" , "Jesse" , "Max" , "Jack" ] years = [ 2010, 2019, 2001, 2016 ] There are many different ways to print items from a list depending on how you want it to look . Print all items on one line Type the list name into a print command to output the complete list . Typing an asterisk * before the list name removes punctuation . cities = [ "Shanghai" , "Sao Paolo" , "Bishkek" , "Asmara" ] print (cities) cities = [ "Shanghai" , "Sao Paolo" , "Bishkek" , "Asmara" ] print (*cities) ['Shanghai', 'Sao Paolo', 'Bishkek', 'Asmara'] Shanghai Sao Paolo Bishkek Asmara Print each item on a separate line To print a list line-by-line use a for loop to cycle through each item. 'city ' is just a variable name and can be replaced with the traditional 'i ' or anything relevant to the context, such as 'colour ' in a list of colours or 'name ' in a list of people. cities = [ "Shanghai" , "Sao Paolo" , "Bishkek" , "Asmara" ] for city in cities: print (city) Shanghai Sao Paolo Bishkek Asmara Print separated items on one line To print separated data elements on the same line then you can use the end command which defines what should go after each item . The example below uses slashes but end = " , " would add comma and space between each element. cities = [ "Shanghai" , "Sao Paolo" , "Bishkek" , "Asmara" ] for city in cities: print (city, end = " / " ) Shanghai / Sao Paolo / Bishkek / Asmara / Print specific list items To print an element with a certain index , put the index in square brackets . But remember that the index starts at 0 not 1. cities = [ "Shanghai" , "Sao Paolo" , "Bishkek" , "Asmara" ] print ( "The first city is" , cities[0]) print (cities[2], "is the third city" ) The first city is Shanghai Bishkek is the third city Create a list of five different of foods . Print all list items on one line . Then print each item on a different line . Finally print just the first and fifth items . Example solution: lettuce yoghurt tomato artichoke tuna lettuce yoghurt tomato artichoke tuna The first item is lettuce The fifth item is tuna Lists Task 1 (Five Foods ) Lists Task 2 (Four Numbers ) Create a list of four integer values . Print all list items on one line separated by colons . Example solutions: 345:123:932:758: 812:153:783:603: Add (Append / Insert) to a List Append items to the end of a list To add a new item to the end of a list use the .append() command. Write .append() after the name of your list, with the new data in brackets . pets = [ "dog" , "cat" , "hamster" ] pets.append( "rabbit" ) print (*pets) fillings = [ "ham" , "cheese" , "onion" ] extra = input ( "Enter another filling: " ) fillings.append(extra) print ( "Your sandwich:" , *fillings) dog cat hamster rabbit Enter another filling: lettuce Your sandwich: ham cheese onion lettuce Insert items to a specific index Use the insert command to place an item in a specific position within the list. Remember that Python counts from 0 so the medals example below puts "silver" as index 2 , which is actually the 3rd item . medals = [ "platinum" , "gold" , "bronze" ] medals.insert(2, "silver" ) print (*medals) names = [ "Stacy" , "Charli" , "Jasper" , "Tom" ] name = input ( "Enter a name: " ) position = int ( input ( "Enter an index: " )) names.insert(position,name) print (*names) platinum gold silver bronze Enter a name: Lena Enter an index: 0 Lena Stacy Charli Jasper Tom Enter a name: Pat Enter an index: 3 Stacy Charli Jasper Pat Tom Use a loop to add items to a list A for loop can be used to add a certain number of items to a list. A while loop can be used to keep adding values until a certain value (e.g. ' stop ' or ' end ') is input. animals = [ ] for i in range (4): animal = input ( "Enter an animal: " ) animals.append(animal) print ( "\nAnimals:" , *animals) animals = [ ] while True : animal = input ( "Enter an animal: " ) if animal == "stop" : break else : animals.append(animal) print ( "\nAnimals:" , *animals) Enter an animal: lion Enter an animal: horse Enter an animal: hyena Enter an animal: squirrel Animals: lion horse hyena squirrel Enter an animal: rhino Enter an animal: gazelle Enter an animal: deer Enter an animal: stop Animals: rhino gazelle deer Example solution: Lists Task 3 (Favourite Musicicans ) Create a list of three musicians or bands you like . Print the list . Then append two new bands using two inputs . Print the list again. Use the sandwich filling example for help. Musicians I like: Lana Del Rey Devon Cole Elly Duhé Enter another musician: Charli XCX Enter another musician: Kenya Grace Musicians I like: Lana Del Rey Devon Cole Elly Duhé Charli XCX Kenya Grace Lists Task 4 (Missing 7 ) Create a list of numbers in order from 1 to 10 but miss out 7 . Use the insert command to add 7 in the correct place . Print the list before and after you insert 7. Example solution: 1 2 3 4 5 6 8 9 10 1 2 3 4 5 6 7 8 9 10 Lists Task 5 ('Land' Countries ) Use a while True loop to input countries that end in 'land' until the word 'finish ' is input . Print the list at the end. Note: You do not need to check if the countries entered are correct. There are also more than four. Example solution: Enter a country ending in 'land': Iceland Enter a country ending in 'land': Poland Enter a country ending in 'land': Switzerland Enter a country ending in 'land': Thailand Enter a country ending in 'land': finish Country list: Iceland Poland Switzerland Thailand Delete (Remove/Pop) from a List Delete items with a specific value To delete data with a certain value use the .remove() command, with the value in brackets . trees = [ "fir" , "elm" , "oak" , "yew" ] trees.remove( "elm" ) print (*trees) fir oak yew trees = [ "fir" , "elm" , "oak" , "yew" ] tree = input ( "Select a tree to remove: " ) trees.remove(tree) print (*trees) Select a tree to remove: oak fir elm yew Delete items with a specific index To delete data in a specific position in your list use the .pop() command, with the position in the brackets . Remember that indexes start at 0 so .pop(0) removes the first item . Negative values start from the end of the list , so -1 is the final item and -2 is the second last item and so on. kitchen = [ "plate" , "cup" , "spoon" , "jug" ] kitchen.pop(0) print (*kitchen) kitchen = [ "plate" , "cup" , "spoon" , "jug" ] kitchen.pop(-2) print (*kitchen) kitchen = [ "plate" , "cup" , "spoon" , "jug" ] index = int ( input ( "Select an index: " )) kitchen.pop(index) print (*kitchen) cup spoon jug plate cup jug Select an index: 1 plate spoon jug Delete all items in a list To delete data in a list use the .clear() command. insects = [ "ant" , "bee" , "wasp" ] insects.clear() insects.append( "hornet" ) print (*insects) hornet Lists Task 6 (Day Off ) Example solution: Create a list with the five week days . Ask the user to input a weekday and remove that day from the list. Print the list. Which day do you want off? Tuesday Your new days of work: Monday Wednesday Thursday Friday Lists Task 7 (May and October ) Create a list with the twelve months in order . Delete May and then October using the pop command by referring to their indexes in the list. Print the list. Note: Be aware the index of each month after May will change when May is popped from the list. Example solution: January February March April June July August September November December Finding the Length of a List To find the length of a list use the len function. You can create a separate variable for the length (shown in the first example below) or use the len command directly (second example). states = [ "Maine" , "Utah" , "Ohio" , "Iowa" ] length = len (states) print ( "There are" , length , "states in the list." ) states = [ "Maine" , "Utah" , "Ohio" , "Iowa" ] print ( "There are" , len (states), "states in the list." ) There are 4 states in the list. Lists Task 8 (Q Words ) Use a while True loop to input words beginning with q until the word ' stop ' is entered. Then use len to find the length of the list and print this value. Note: You do not need to check if the entered words actually start with q. Example solution: Input a Q word: question Input a Q word: quick Input a Q word: quiet Input a Q word: quandry Input a Q word: stop You wrote 4 Q words! Cycle Through List Items A for loop can be used to cycle through each item in a list. The following examples present some ways that this may be used. This program uses a for loop to add a word (David) before each list item. davids = [ "Beckham" , "Attenborough" , "Schwimmer" , "Tennant" , "Lynch" ] for i in range (5): print ( "David" , davids[i]) David Beckham David Attenborough David Schwimmer David Tennant David Lynch An if statement can be used within a for loop to check the value of each item . The example below checks how many items are 'medium'. sizes = [ "small" , "medium" , "small" , "large" , "medium" , "small" ] count = 0 for i in range (6): if sizes[i] == "medium" : count = count + 1 print ( "There were" ,count, "medium choices." ) There were 2 medium choices. The program below uses a while loop to allow entries until 'stop ' is input then a for loop to check the value of each item . Because the final length of the list is not known when the program starts, the len command is used in the range of the for loop . sports = [] fcount = 0 rcount = 0 while True : option = input ( "Choose football or rugby: " ) sports.append(option) if option == "stop" : break for i in range ( len (sports)): if sports[i] == "football" : fcount = fcount + 1 elif sports[i] == "rugby" : rcount = rcount + 1 print ( "\nResults:" ,fcount, "people chose football and" ,rcount, "chose rugby." ) Choose football or rugby: rugby Choose football or rugby: rugby Choose football or rugby: football Choose football or rugby: rugby Choose football or rugby: football Choose football or rugby: stop Results: 2 people chose football and 3 chose rugby. Lists Task 9 (Over 25 ) Create a list with the following eight numbers: 13, 90, 23, 43, 55, 21, 78, 33 Use a for loop to cycle through the list and check if each item is over 25 . Use a count variable to increase by 1 if the number is over 25. At the end print how many numbers are over 25 - there are five . Example solution: 5 numbers are over 25. Lists Task 10 (Favourite Lesson ) Use a while True loop to keep inputting school subjects until ' done ' is entered. Keep a count of how many times ' Maths ' is entered. Print the total number of people who entered maths. Example solution: Enter a subject: English Enter a subject: Maths Enter a subject: Art Enter a subject: Maths Enter a subject: History Enter a subject: done There were 2 people who chose maths. Sorting Lists The .sort() command will sort elements in a list into alphabetical order (if a string ) or numerical order (if a number ). names = [ "Robb" , "Jon" , "Sansa" , "Arya" , "Bran" , "Rickon" ] print ( "Original:" , *names) names.sort() print ( "Sorted:" , *names) Original: Robb Jon Sansa Arya Bran Rickon Sorted: Arya Bran Jon Rickon Robb Sansa numbers = [56,98,23,12,45] numbers.sort() print (*numbers) 12 23 45 56 98 The .sort() command can be used to sort values in descending order by including reverse = True in the brackets. names = [ "Robb" , "Jon" , "Sansa" , "Arya" , "Bran" , "Rickon" ] print ( "Original:" , *names) names.sort(reverse = True ) print ( "Sorted:" , *names) Original: Robb Jon Sansa Arya Bran Rickon Sorted: Sansa Robb Rickon Jon Bran Arya numbers = [56,98,23,12,45] numbers.sort(reverse = True ) print (*numbers) 98 56 45 23 12 Lists Task 11 (Sorted Fruit ) Example solution: Use a for loop to append six fruits to an empty list. Sort the list into alphabetical order and print it. Enter a fruit: strawberry Enter a fruit: kiwi Enter a fruit: lemon Enter a fruit: pear Enter a fruit: orange Enter a fruit: mango Sorted fruit: kiwi lemon mango orange pear strawberry Searching Through Lists A simple if statement can be used to see if a certain value appears within a list. names = [ "Alex" , "Bill" , "Charlie" , "Darla" ] name = input ( "Enter a name: " ) if name in names: print ( "Yes," , name , "is in the list." ) else : print ( "Sorry," , name , "is not in the list." ) Enter a name: Bill Yes, Bill is in the list. Enter a name: Sadie Sorry, Sadie is not in the list. Lists Task 12 (Packed Suitcase ) Example solutions: Create a list with five items to take on holiday. Ask the user to input an item and use an if statement to check if it is or isn't in the list. What should I pack? sun cream I've already packed sun cream What should I pack? toothpaste Whoops! I forgot to pack toothpaste Calculating the Sum of a List To calculate the sum of a list of numbers there are two methods. Using Python's built-in sum function : numbers = [1,4,2,3,4,5] print ( sum (numbers)) Both methods will result in the same output : 19 Using a for loop to cycle through each number in the list and add it to a total . numbers = [1,4,2,3,4,5] total = 0 for number in numbers: total = total + number print (total) Lists Task 13 (Sum and Average ) Example solution: Use a for loop to ask the user to input 5 numbers and append each to a list. Use the sum command to output the total and use it calculate the average . Enter a number: 6 Enter a number : 7 Enter a number : 6 Enter a number : 9 Enter a number : 4 The total is 32 The average is 6.4 Extending a List .extend() can be used in a similar way to .append() that adds iterable items to the end of a list . This commands works well with the choice command (imported from the random library ) to create a list of characters that can be randomly selected. The code below adds a lowercase alphabet to an empty list and then, depending on the choice of the user, adds an uppercase alphabet too. The choice command is used in a loop to randomly select 5 characters. Using .extend() to make a random 5-character code from random import choice list = [] list. extend ( "abcdefghijklmnopqrstuvwxyz" ) upper = input ( "Include uppercase letters? " ) if upper == "yes" : list. extend ( "ABCDEFGHIJKLMNOPQRSTUVWXYZ" ) code = "" for number in range (5): letter = choice (list) code = code + letter print ( "Your five character code is" , code) Possible outputs: Include uppercase letters? yes Your five character code is yPfRe Include uppercase letters? yes Your five character code is GJuQw = Include uppercase letters? no Your five character code is gberv Extend treats each character as an indidual item whereas append adds the whole string as a single entity . Most of time append would be used, but extend is suitable for a password program as additional individual characters can be added to a list depending on the parameters (e.g. lowercase letters, uppercase letters, numbers and special characters). list = [] list. extend ( "ABCD" ) list. extend ("EFGH" ) print (list) list = [] list. append ( "ABCD" ) list. append ("EFGH" ) print (list) ['A','B','C','D','E','F','G','H'] ['ABCD' , 'EFGH'] = = Practice Task 14 Use the code above (for a 5-character code ) to help you make a password generator . Ask the user if they want uppercase letters , numbers and special characters and use the extend command to add them to a list of characters if they type yes (you should extend lowercase characters into an empty list regardless, like in the code above). Use a for loop and the choice command (imported from the random library) to randomly generate a 10-character password . Example solutions: Include uppercase letters? yes Include numbers? yes Include special characters? yes Your new password is RjWSbT&gW5 Include uppercase letters? no Include numbers? yes Include special characters? no Your new password is hdf8se9y2w ⬅ Section 7 Practice Tasks 8b - 2D Lists ➡

Learn about different types of operating systems and the various roles that they manage, including memory, security and processing. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.4: Operating Systems Exam Board: OCR Specification: 2016 - Unit 1 An operating system (OS) is software that manages the resources of a computer system . The operating system is loaded by the BIOS (Basic Input / Output System). Types of Operating System Single user operating systems are found on most desktop computers, laptops and tablets where only one person will use the device at a single time. Multi-user operating systems allow more than one user to access the processor simultaneously , such as a server that users, with correct permissions , can access remotely . However, one user should not be negatively impacted by another user on the same operating system and security must be managed carefully as data may be visible to other users . Single Processor operating systems have only a single processor (CPU), which is shared between users by dividing the CPU time into time-slices and allocating one of these to each user in turn. The time-slices are very short, giving each user the impression that their programs are running continuously. Multiple Processor operating systems have more than one processor (CPU). Users still have to share processors and it is a more complicated system but performance is improved as there are fewer users per processor. Some supercomputers have thousands of processors running in parallel. Operating systems can also be off-the-shelf , open-source or bespoke . See 2.1 . What are the roles of an Operating System? Manage Input / Output Devices Receives data from input devices (e.g. a keyboard). Sends data to output devices (e.g. a monitor) in the correct format . Manage Printing Checks the printer is free then uses spooling (storing data in a queue ) to print documents in order. Manage Backing (Secondary) Storage Ensures data is stored correctly and can be retrieved from secondary storage devices (e.g. hard drive / SSD ). Organises files in a hierarchical structure. Manage Memory (RAM) Ensures that programs / data do not corrupt each other and are stored in correct memory locations . Manage Processes Ensures different processes can utilise the CPU and do not interfere with each other or crash. On most OS the tasks appear to run simultaneously . Manage Security Allows users to create, manage and delete user accounts with different permissions. Allows users to logon and change passwords . User Interface The final function of an operating system is to provide a user interface . This includes: A folder and file system is displayed and manipulated allowing for copying , searching , sorting and deleting data. Icons are displayed to represent shortcuts to applications and files. Multiple windows can be opened at the same time and switched between. The interface can be customised , such as changing font sizes and the desktop background . System settings can be accessed such as network and hardware options . Q uesto's Q uestions 2.4 - Operating Systems: 1. Describe five different roles of the operating system. Include the importance of the operating system in performing each role. [ 5 ] 2. What is the difference between single user and multi-user operating systems? [2 ] 3. What is the difference between single processing and multi-processing operating systems? [2 ] 4. Using your knowledge from 2.1 Software Types, explain two advantages and one disadvantage to a company if they decided to use a closed source operating system. [6 ] 2.3 Utility Software Topic List 2.5 Communication Methods

Learn how to use tags to format text in HTML, including how to underline, italicise and embolden text. Also, learn about heading size and paragraphs. 3. Tags for Text HTML Guide Watch on YouTube: Remember to write the tags for everything you want the user to see between the and tags. Headings Time to add text to your web page such as headings and paragraphs. To write a large heading , use and To write headings in a smaller size, use numbers between 1 and 6. Add a large heading and a sub-heading to your webpage. paragraph Paragraphs Typing text between the and tags will create a paragraph . Add at least three different paragraphs to your webpage. bold underline italics Bold, Underline & Italics You can format your text by changing it to be bold , underlined or italicised (slanted). Now you have text on your web page, you can add hyperlinks to take viewers to different websites. In the paragraphs you have already written, add at least 1 bold tag, 1 underline tag and 1 italics tag. 2. Essential Tags HTML Guide 4. Hyperlinks

Learn how to handle numbers in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 9b - Number Handling Rounding Numbers The round() command is used to round a value to a certain number of decimal places . Type your variable into the round command brackets, add a comma and state the number of decimal places to round to. Fixed Decimal Places (Currency) The round function will remove any trailing 0s , for example 30.1032 will become 30.1 even if you specified to round to 2 decimal places . Instead, you can use an f -string and write :.2f after a bracketed variable to use exactly 2 decimal places . The number can be changed from 2. books = int ( input ( "How many books would you like to buy? " )) total = books * 3.99 print ( f"The total is £ {total:.2f} - Thanks for your order!" ) How many books would you like to buy? 10 The total is £39.90 - Thanks for your order! How many books would you like to buy? 100 The total is £399.00 - Thanks for your order! Practice Task 1 Ask the user to enter any large number. Ask the user to enter another large number. Divide the two numbers and print the answer to 3 decimal places. Example solution: Using Numbers as Strings The following techniques all require the integer to be converted into a string first using the str command. Just like a string, you can shorten a variable to only display a certain length . Remember that Python starts at zero . You can select a specific digit in the same manner as when selecting characters in a string. If you want to use your variable as an integer again later you would need to convert it from a string to an integer using the int command. Again, reversing a number is the same as reversing a string. You can also use other string handling methods such as .startswith() or .endswith() Practice Task 2 Ask the user to enter a 10 digit number. Select the 2nd and 8th digits and add them together. Print the total. Example solution: ⬅ 9a - String Handling Section 9 Practice Tasks ➡