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Learn about HTML, CSS, JavaScript, search engine indexing, the PageRank algorithm and client-side and server-side processing. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 3.4 - Web Technologies Specification: Computer Science H446 Watch on YouTube : HTML CSS JavaScript Search engine indexing PageRank algorithm Server-Side & Client-Side Processing This topic looks at the languages that web pages are comprised of (HTML , CSS and JavaScript ) as well as search engines and network processing (client-side and server-side ). HTML HTML ( HyperText Markup Language ) is the standard language used to create and structure web pages . It uses tags enclosed in angle brackets to define elements on a page . A web page begins with , which contains a section for metadata , links and the

Test your understanding of working with files in Python, including reading, searching, writing and editing. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Python - Section 10 Practice Tasks Task One Create a file in Python called DaysOfTheWeek.txt. Write the days of the week into the file in a single print line but put each day on a new line. Check the file to see if it has worked. Example solution: Task Two Create a file called Colours.txt. Use a for loop to ask the user to enter 8 different colours. Write each colour onto the same line, with a space between the colours. Close the file and open it again in read mode and print it. Example solution: Task Three Create a file named "Holiday.txt". Ask the user to enter the family name, destination and and number of passengers. Print each family's details on their own line. Bonus: Edit this program to add a search feature to look for the family name. Example solution: Task Four Use the holiday file from task three above. You are going to change the destination. Ask the user to enter a family name and then a new destination. Update the destination with the new value. Check the file to ensure the destination has been updated successfully. Use section 10c to help you with this task. Example solution: ⬅ 10c - Remove & Edit Lines 11 - Graphical User Interface ➡

Learn about the importance of client requirement specifications and the need for specific elements such as functional requirements, process constraints and data formats. 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) 4.2 - Client Requirement Specifications Watch on YouTube : Client Requirement Specifications A client requirement specification is a detailed document that outlines what the client needs from a new system . Elements include the new system’s purpose , functional and non-functional requirements , constraints and success criteria . As well as understanding the importance of creating client requirement specifications , you need to know the purpose of each element and how they can be gathered using the methods from section 4.1 . Client Requirement Specifications Elements of Requirement Specifications Specifications ensure developers and stakeholders fully understand what the client wants the system to do , avoiding misunderstandings and costly changes later. There are several elements of client requirement specifications you need to know : Purpose of the new system Current system deficiencies Requirements ( functional and n on-functional ) Data formats Process constraints Version and source control Client-defined constraints Three considerations for data storage location are local/onsite , cloud and physical storage devices . Budget Time Integration Software Hardware Data storage location Q uesto's Q uestions 4.2 - Client Requirement Specifications: 1. Give three reasons why it is important to create a client requirement specification . [8 ] 2. Describe the purpose of each client-defined constraint . [6 ] 3. Describe the difference between functional and non-functional requirements . [ 2 ] Some cloud storage data centres are built in cold climates , such as Sweden and Norway , to reduce cooling costs for servers that run 24/7 . D id Y ou K now? 4.1 - Gathering Client Requirements Topic List 4.3 - Decomposition Methods

Learn about the wide range of style data and information can be presented in, both digitally and physically. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 2.1 - Information Styles Exam Board: OCR Specification: 2016 - Unit 2 There are many different ways that information can be styled and presented , both on-screen and physically . There are many more benefits and limitations to using each information style but some key ideas have been described below. T Text Text is a written (or typed ) format of information. ✓ Text provides detailed summaries and explanations . ✓ The format of text can be changed to suit its purpose (e.g. include bullet points or different colours). ✓ Text can be written in different languages so that all literate people can understand. X Large amounts of text can be difficult and time-consuming to read. It is generally less engaging than most other methods. X Text may include spelling errors or be factually incorrect . Graphics Graphics are a visual form of information. Examples include logos , photographs and diagrams . ✓ Graphics are multilingual - they can be understood by anybody regardless of their spoken language. Companies like IKEA will use the same graphics globall y . ✓ Graphics can present an idea or message immediately and can use associations (e.g. the colour red is associated with temperature or anger). ✓ Graphics are a more engaging method of presenting information than text. X Images may take longer to load over a data-restricted network, for example, images in an email may not be automatically downloaded. Video Videos are visual formats of information, often with audio . ✓ More engaging and easier to follow than reading large amounts of text. ✓ Videos can be used to convey a message in a short space of time , e.g. television adverts. ✓ Audio can be added to videos such as music for engagement or narration to explain a process. X Videos usually take up a relatively large amount of storage space , longer videos may take time to upload / download / transfer along a network. X Videos take a long time to create including filming, editing and narration. Animated Graphics Animated graphics are images with multiple frames , such as an animation of the heart showing individual steps that a user can pause and step through in their own time. ✓ Can be used to show a process and is easier to understand than reading text. ✓ Can be understood by all ages and language speakers . X Creating an animated graphic takes time to create , especially educational resources with multiple frames and annotation. 9 Numerical Numerical information is represented by numbers . This can include a wide array of different information including statistics, financial data, dates, ages and distances . ✓ Statistical data is easier to understand and manage in a numerical format than standard text - 234,567 is simpler to work with than "two hundred and thirty-four thousand, five hundred and sixty-seven". ✓ Numerical data can be exported into spreadsheets and presented as graphs to visualise the dat a . X Long numbers can be entered by humans incorrectly and lead to incorrect results . X Formatted data like telephone numbers cannot be stored as numerical because numerical does not allow spaces and does not allow the number to start with 0 . Audio Audio is an information type using sound waves. A common form of audio is music , such as the millions of tracks stored in music libraries like Spotify and YouTube. Non-music examples include spoken instructions and podcasts . ✓ Users can listen to information when they are otherwise busy and could not read, such as when walking or driving. ✓ Visually impaired users who are unable to read can still hear audio and interact with voice recognition software . ✓ Some users prefer listening to instructions rather than reading text . X Audio may not be suitable in some environments e.g. noisy areas . X Words may be misheard and misunderstandings made, possibly due to pronunciations or accents. Tactile Images Tactile images are a form of physical information that can be interpreted by touch . Specialist software is used to create raised lines on paper that people can experience by touching . Geographers can create 3D physical objects of environments such as valleys or volcanoes. This allows researchers and land surveyors to have a better understanding of a geographic area. ✓ Users can better understand a physical environment or prospective design if it is physically built. ✓ Visually-impaired users can feel the object instead of being able to see it. ✓ The tactile image can be used as a prototype for a target audience to feel and comment on. X It is difficult to share a tactile image without physically moving it, unlike digital or paper information styles. X Creating a tactile image requires specialist equipment like a 3D printer. *screams* Subtitles Subtitles are a textual form of information that can be shown along with visual data such as a video. Subtitles are written to transcribe audio , such as speech, into words . ✓ Hearing-impaired users can access audio information formats such as video by reading the subtitles. ✓ Subtitles can be used in noisy environments or when sound cannot be played. ✓ Subtitles can be used for translated speech , such as in promotional videos or television programmes. X Auto-generated subtitles are often incorrect . X Subtitles written by a human take a long time to type up and sync in time with the audio. Tables & Spreadsheets Tables and spreadsheets can store both numerical and textual data ready for analysis . Examples include simple database tables and financial spreadsheets of a company's profits this year. Microsoft Access is an example of database software that uses tables and Microsoft Excel is an example of spreadsheet software. When using spreadsheets (or databases) records can be locked ('record locking' ) so that only one person can make edits at any one time . Edits will be saved before unlocking the file. This will stop data being incorrectly overwritten and will ensure that the data in the spreadsheet is up-to-date , accurate and fit for purpose . Spreadsheets can be linked to other documents such as forms to directly import data from. This data can be ordered into different groups and conditional formatting can be used to automatically organise and style the data. Graphs and charts can be created using values stored in a spreadsheet to easily visualise the data . Modelling can be used to see the effect of variable changes (e.g. will raising the price of one product affect overall profit?). Database tables use queries (advanced searches) to find and display data based on given criteria (such as all males under 35). Mail merge can be used to automatically send emails to the customers highlighted in the query . A report can be generated from the query results to display the information in a structured format . This can be used to make decisions and analyse data . Boolean Boolean is a data type that can only have one of two specified values . These values are most commonly 'True' and 'False' or sometimes 'yes' and 'no'. Braille Braille is an example of a tactile image that can be physically touched . Braille characters represent letters or numbers that can be 'read' by touch - used primarily by those with visual impairments . Devices like braille terminals convert characters on a screen into braille, line-by-line so that blind people can understand the information through touch . A braille printer is used to output braille dots onto paper. ✓ Allows visually impaired users to interact with a computer system using a braille terminal . ✓ A braille printer can print documents written using braille to be given to blind people to 'read'. X Braille terminals can only display a limited amount of information at a time. X Braille is not used by many people except visually impaired people so few resources are written using braille. Charts & Graphs Charts and graphs can be used to present numerical data in a format that is easier to visualise and understand . They can be labelled to show different data values and they make it easier for viewers to identify trends and make comparisons between data. Large quantities of data, like census results, are easier to visualise in a graph than reading huge tables of numbers. ✓ Charts present numerical data in a format that is easier to visualise and understand . ✓ Charts and graphs can summarise information into one image data that would take paragraphs to explain in text. ✓ Displaying information in a graph allows users to easily identify trends and make comparisons between data . X Charts can be misleading or can display incorrect information if the numerical data is wrong. Q uesto's Q uestions 2.1 - Information Styles: 1. Describe the following information styles : a. Tactile Images [2 ] b. Braille [2 ] c. Boolean [2 ] 2. Describe two advantages and two disadvantages for each of the following information styles : a. Text [8 ] b. Graphics [8 ] c. Video [8 ] d. Animated Graphics [8 ] e. Numerical [8 ] f. Audio [8 ] g. Tactile Images [8 ] h. Subtitles [8 ] i. Braille [8 ] j. Charts & Graphs [8 ] 3a. Spreadsheets and database tables can be record locked . Explain what record locking is and why it is used . [4 ] 3b. Describe different ways that spreadsheets can be used. [6 ] 3c. Describe different ways that databases can be used. [6 ] 1.7 & 1.8 - Internet Pros & Cons 2.2 - Information Classification Topic List

Learn about the Central Processing Unit (CPU), the four components within and Von Neumann architecture. Based on the 2020 Eduqas GCSE (WJEC) specification. Exam Board: Eduqas 1.1 The Central Processing Unit (CPU) Specification: 2020 The Central Processing Unit ( CPU ) is the most important component in any computer system. The purpose of the CPU is to process data and instructions by constantly repeating the fetch - decode - execute cycle . CPU Components The control unit directs the flow of data and information into the CPU. It also controls the other parts of the CPU . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . The registers are temporary storage spaces for data and instructions inside the CPU. The registers are used during the FDE cycle . Five essential registers are explained in 1.2 . Cache memory is used to temporarily store data that is frequently accessed . Cache memory is split into different levels . Level 1 and level 2 (L1 & L2) are usually within the CPU and level 3 (L3) is just outside it. See 1.3 and 1.5 for more information about cache. You should know: The control unit is also known as the controller and cache memory is sometimes called internal memory . Computer Architecture The way a computer is designed and laid out is known as its architecture . The most common type of computer architecture is Von Neumann . Von Neumann Architecture The CPU is the most important component in Von Neumann architecture as it is constantly fetching and decoding instructions from RAM and controlling the other parts of the system . Von Neumann architecture also stores both instructions and data in memory . Being able to store programs in memory allows computers to be re-programmed for other tasks - this enables it to multitask and run several applications at the same time. Data input and output is another key feature of this architecture. An alternative architecture is Harvard , which features the control unit as the most essential component. Q uesto's Q uestions 1.1 - The Central Processing Unit (CPU): 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] 2a. Draw a diagram of the CPU , use the same symbols as shown on this page. [ 4 ] 2b. Label the four main components of the CPU. [ 4 ] 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] d. Cache memory [ 2 ] 4a. Describe the key features of Von Neumann architecture . [ 3 ] 4b. Explain why storing data in memory is important. [ 1 ] 4c . State an alternative architecture . [ 1 ] Theory Topics 1.2 - The FDE Cycle

Learn how to use App Inventor 2 to create simple programs. Try to complete tasks 4, 5 and 6 on this page. Perfect for Key Stage 3 students to experiment with block coding, objects and properties. App Inventor Tasks 4, 5 & 6 - Using Variables This page will teach you how to make three simple apps that use variables . These apps will prepare you for the final program - the Pop-up Blob game. App #4 - Button Masher The first app to make is a simple program that counts how many times a button is pressed (but don't press it too much! ) This app will introduce you to using variables in App Inventor. Open App Inventor 2 (use the button below) and create a new project. You will need to log in with a Google account. App Inventor 2 Firstly, grab a button and two labels and place them in the Viewer . Using the Properties tab, you need to make the following changes: Button Text to 'Press Me!' Button Height to 60 pixels and Width to 'Fill parent...' Label 1 Text to 'Number of Presses' Label 2 Text to '0' Both Label 1 and Label 2 Width to 'Fill parent...' Both Label 1 and Label 2 TextAlignment to 'centre : 1' In the Components tab change the component names to be easier to code later. Switch to Blocks layout and drag an initialize global to block into the centre. In the blank space type 'Presses' - this is the name of the variable that will store how many times the button has been pressed. Drag a 0 block from Math. This will set the number of presses to 0 when the app starts. Drag a when ButtonPresses Clicked from the ButtonPresses section and add the necessary code inside. This code increases the variable value of Presses by 1 every time the button is clicked. It also changes the LabelPresses text to display the number of presses. Improve Your App As you will have seen in the video at the top, I programmed the app to go a bit crazy when 35 presses were recorded. In the code below I have shown how to use an if then block to check if the number of presses is 35. If it is then I have made the button invisible - this is an important feature we will use in later programs. Copy this code and add the following features to the then part of the if statement: Set the background colour to black. Change the Label1 Text Colour to white. Change the Label1 Text Size to 40. Change the Label1 Text to 'You broke it...' Program 4 Complete! App #5 - Timer The second app to make is a timer that counts up one second at a time. It also needs a reset button that sets the timer back to 0 again. It will introduce you to the clock component and enabling / disabling components. Open App Inventor 2 (use the button below) and create a new project. You will need to log in with a Google account. App Inventor 2 The code for this program is straightforward; it will take more effort getting the layout right. In the Palette tab, drag a HorizontalArrangement from the Layout section. It will look like an empty grey box at first. Grab a Button as well and place it underneath. Now drag two labels into the grey box and place the second one directly after the first, it may take a few attempts to get them to appear side by side like below: The last component to drag over is Clock (it is in the Sensors section in the Palette tab). It will go into its own section underneath: Change the name of some of the components so that they make more sense. Now to make some changes in the Properties tab. You should know enough by now to work out how to change your components so that it looks like this in your Viewer : Change your layout to Blocks and add the code blocks to the right. This code makes the Label named Seconds update by 1 every second, just like a timer. The code to the left will make the Label named Seconds reset to 0 when the button is pressed. Improve Your App As you will have seen in the video at the top of this task, I added a pause/unpause button that will set the enabled feature of the timer to true or false. You will need to complete the following steps (I've been deliberately vague to make it a challenge - break it down into small steps and use the colours to help you): Add a new button. Add code that, when the new button is clicked , checks if the TimerEnabled is true . If it is, then change TimerEnabled to false . Else change it to true . Now you also need to change the Text of the Button to read either "Pause" or "Unpause" . Program 5 Complete! App #6 - Windy Day The third app to make is an app that blows leaves around your screen. It will introduce you to random numbers, the canvas and coordinates . Open App Inventor 2 (use the button below) and create a new project. You will need to log in with a Google account. App Inventor 2 In the Palette tab, drag a Canvas from the Drawing and Animation section. A Canvas allows sprites (objects) to move around inside of it. In Properties , change the Height and Width of Canvas to 'Fill parent...' for both, so it fills the whole screen. In the Palette tab, drag over five ImageSprites from the Drawing and Animation section and drop them anywhere inside the canvas. Download the leaf picture with all App Inventor images on the basics page here . Upload the leaf image it in the Media tab. In the Components tab change the names of your ImageSprites to be leaf1, leaf 2 etc. For each leaf sprite, in the Properties tab, change the Picture to the leaf you just uploaded and change Height and Width to 30 pixels each. Finally, in the Palette tab, in the Sensors section, drag over a Clock . Your Viewer should look like the image to the left. X axis Y axis 0 300 500 Now for an explanation of coordinates. Each sprite (leaf) has an x coordinate (horizontal) and a y coordinate (vertical). For example, the leaf in the top right would have coordinates of x = 270 and y = 100. Can you work out approximately what the other leaves coordinates would be? What the code blocks below do is randomise the x and y coordinates for leaf1 every second. The word integer means a whole number . Use this code and add to it to make all 5 leaves randomly change coordinates. Improve Your App Add a pause / unpause button, just like in the Timer app that pauses the timer so that the leaves stop blowing (and starts them blowing around again too). Find a nice picture (maybe of a park?) online and upload it in the Media tab. Set this as the Canvas BackgroundImage . Add an audio file of some whooshing (why not record it yourself?). Program 6 Complete! Task 7 KS3 Home

Learn about the five data types - character, string, integer, real and Boolean. Also learn about casting. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 2.2: Data Types Exam Board: OCR Specification: J277 Watch on YouTube : Data Types What are the different data types? When programming, variables should be given appropriate data types . Character A single character , such as a letter, number or punctuation symbol. Examples: T 8 ? String A sequence of characters , including letters, numbers and punctuation. Examples: Harry Waters 14:50pm Ice Age 4 Integer A whole number . Examples: 475 -8432 56732 Real Boolean A decimal number . Examples: 65.3 -321.1234 909.135 An answer that only has two possible values . Examples: True / False Yes / No 0 / 1 Telephone numbers are always stored as a string , not an integer. Casting Converting the value of a variable from one data type into another is known as casting . Python automatically assumes an input is a string so the int() command is used to cast an input into an integer . Other Python commands for casting include str() and float() . For example: age = int(input("Enter your age: ")) Q uesto's Q uestions 2.2 - Data Types: 1. List the five data types , giving an example of each . [ 5 ] 2. State which data type is most suitable for the following variables: a. Age [ 1 ] b. Surname [ 1 ] c. Height (in metres) [ 1 ] d. First Initial [ 1 ] e. Phone number [ 1 ] f. Right-Handed? [ 1 ] 3. Explain what casting is and give a programming situation in which it would be used . [ 2 ] 2.1 - Programming Fundamentals Theory Topics 2.3 - Additional Techniques

Learn about how information can be categorised for both individuals and organisations. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 3.2 & 3.3 - Information Categories Exam Board: OCR Specification: 2016 - Unit 2 Categories of Information for Individuals Communication Texting a friend about dinner plans, sending an email to a family member in another country, ringing work because trains are delayed. Education and Training Revision textbooks, logging into a virtual learning environment to upload a completed worksheet, hand-written feedback sheets from a teacher after an exam. Planning Using a shared document to arrange meeting dates, using a webpage hosting a bus timetable, a calendar app. Financial Using a bank statement to plan holiday saving, creating a spreadsheet of expenditure this month, logging in to a secure web page to buy a present online. Entertainment Reading a film review in a magazine, listening to a podcast about trains, watching a tutorial on DIY. Research Using online encyclopedias for a school project, searching for research articles to write an essay, using a recipe book Location Dependent Find local pizza restaurants, searching for emergency dental care on holiday, Pokemon GO Categories of Information for Organisations Knowledge Management & Creation Managing information across an organisation e.g. sharing information between branches in different cities. Management Information Systems (MIS) A system that provides an overview of key information e.g. the location and contact details of each charity worker in a disaster area. A decision can be made on overall figures or individual data as appropriate. Financial Analysis & Modelling Analysing trends e.g. determining the top selling products in a year or weekly cash flow, to create models of customer/user behaviour. Contact Management Managing contact between a business and the customer e.g. tracking appointments at a doctor’s surgery. Internal and External Communication Providing a communication medium to staff and/or customers e.g. posting Christmas opening times on the website, or sending a staff email invite to the Christmas party. Big Data Any data too large or complex for traditional data analysis techniques to be used e.g health data on the population of an entire country. Marketing, Promotion & Sales Identifying patterns or trends in sales figures, so that certain products or areas can be targeted, e.g. to plan marketing campaigns. Decision Making Using available information to make decisions, e.g. a charity deciding on the amount of aid to be sent to a disaster area based on local data. Q uesto's Q uestions 3.2 & 3.3 - Information Categories: 1. Describe two examples of each category of information used by individuals : Communication Education & Training Entertainment Planning Financial Research Location Dependent [2 each ] 2. Describe two examples of each category of information used by organisations : Knowledge Management & Creation Management Information Systems (MIS) Marketing, Promotion & Sales Financial Analysis & Modelling Contact Management Decision Making Internal & External Communication Big Data [2 each ] 3.1 - Data vs. Information Topic List 3.4 - Stages of Data Analysis

Learn about software errors and troubleshooting methods of solving them. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.6 - Software Troubleshooting Exam Board: OCR Specification: 2016 - Unit 1 A software error occurs when a program or process stops working as expected. Software errors usually occur when programs are badly written or if a user inputs unexpected data . Common Faults System Freeze The computer freezes and pressing keys or moving the mouse gives no response . Commonly caused by having too many applications running simultaneously or a virus using too much memory . Unexpected Reboot To try and fix errors, a computer might get stuck in an endless loop of booting and rebooting . Other systems may frequently restart without warning . Stop Error This occurs after a fatal system error when the operating system stops , usually because of a driver software issue . Commonly known as the 'blue screen of death ' on Windows-based systems. Update Error While designed to fix errors, updates can sometimes bring more problems if they interfere with the current software . Troubleshooting Tools for Software Errors Event Viewer (Logs) If a software error does occur, then the same characteristics as a hardware error should be logged , such as the time and date of the error , the user logged in , and the device's problem history . Memory Dump Copies and displays the contents of RAM at the time of a crash to help a technician discover what happened . Baselines Before After A comparison of what the system is like after a crash compared to a fixed point in time beforehand. The baseline can be used to see differences which may have caused the computer to fail . Anti-Virus Checks if malware is running on a device, using up resources and slowing the system down. It could then be quarantined and deleted by the anti-virus. Installable tools can also be downloaded to investigate the system and find the cause of the problem . They may help detect corrupted files , uncover deleted files , and resolve other general hardware or software issues . Q uesto's Q uestions 2.6 - Software Troubleshooting: 1. Describe each of the four common types of software error : a. System Freeze b. Stop Error c. Unexpected Reboot d. Update Error [2 each ] 2. Describe each type of troubleshooting tool and explain how it can be used to discover and fix software errors. a. Event Viewer b. Memory Dump c. Baselines d. Antivirus Software e. Installable Tools [ 2 each ] 2.5 Communication Methods Topic List 2.7 - Protocols

Learn about the differences between CISC and RISC processors, GPUs and multicore and parallel systems. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 1.2 - Types of Processor Specification: Computer Science H446 Watch on YouTube : CISC and RISC GPUs Multicore & parallel systems Instruction Sets An instruction set is the complete list of machine code instructions a CPU is designed to execute as part of the FDE cycle . CISC (Complex Instruction Set Computer ) CPUs have a large set of complex instructions , so tasks can be achieved in fewer lines of code , but some instructions take multiple clock cycles . RISC (Reduced Instruction Set Computer ) CPUs use a smaller set of simple instructions , each designed to execute in a single clock cycle , making execution faster but sometimes requiring more instructions overall . GPUs A GPU (Graphics Processing Unit ) is a co-processor with thousands of smaller cores designed for parallel processing . This is in contrast to the CPU , which has fewer but more powerful cores . GPUs are used for rendering images , animations and video for fast , realistic graphics in games and multimedia . Because of their ability to handle many calculations at once , GPUs are widely used for non-graphical purposes too, such as machine learning , scientific simulations , data analysis and cryptocurrency mining . Multicore & Parallel Systems A multicore processor has multiple independent cores on a single CPU chip . Each core can carry out its own FDE cycle , so tasks can be split up , enabling multitasking and faster processing . However, only software designed to use multiple cores will benefit from this increased performance . A parallel system uses multiple processors (or cores ) working together on the same problem at the same time . This may involve multiple cores within one CPU or multiple CPUs in a single machine . Parallel processing greatly improves performance for tasks that can be divided into smaller sub-tasks , such as simulations and graphics rendering . However, some problems cannot be parallelised because they must be executed sequentially . Q uesto's K ey T erms Instruction Sets: instruction set, complex instruction set computer (CISC) , reduced instruction set computer (RISC) GPUs: graphics processing unit (GPU) Multicore Systems: multicore systems, parallel processing D id Y ou K now? Sony coined the term ' GPU ' for the PlayStation (1994), making it one of the first home consoles with a dedicated graphics processor . The term was later popularised further by NVIDIA in 1999 with the GeForce 256 . 1.1 - The Processor A-Level Topics 1.3 - Input, Output & Storage

Learn about the five types of primary storage - RAM, ROM, cache, flash and virtual memory. Based on the 2020 Eduqas (WJEC) GCSE specification. 1.3: Primary Storage (Memory) Exam Board: Eduqas Specification: 2020 Storage in a computer system is split into two categories. Primary Storage: Very quick to access because it is attached to the motherboard . Typically smaller in storage size . Sometimes called ‘main memory’ . Secondary Storage: Slower to access because it is not directly embedded on the motherboard . Typically larger in storage size . Sometimes called ‘backing storage’ . Storage is also split into two types - volatile and non-volatile . Volatile storage is temporary - data is lost whenever the power is turned off . Example: RAM Non-volatile storage saves the data even when not being powered . Data can be stored long-term and accessed when the computer is switched on . Example: ROM Types of Primary Storage (Memory) Random Access Memory (RAM) RAM is volatile (temporary) storage that stores all programs that are currently running . RAM also stores parts of the operating system to be accessed by the CPU. RAM is made up of a large number of storage locations, each can be identified by a unique address . Read-Only Memory (ROM) Cache Memory ROM is non-volatile storage that cannot be changed . ROM stores the boot program / BIOS for when the computer is switched on. The BIOS then loads up the operating system to take over managing the computer. Cache memory is volatile (temporary) storage that stores data that is frequently accessed . It is very quick to access because it is closer to the CPU than other types of memory like RAM. The three levels of cache memory are explained in more detail in 1.5 . RAM ( R andom A ccess M emory) ROM ( R ead O nly M emory) Cache Memory Flash Memory Flash memory is editable so it can be read and written to . It is also non-volatile so it can be used for long-term data storage even when the system is not powered on. Flash memory is also used for secondary storage devices like USB sticks and solid-state drives - see 1.4 . Virtual Memory When a computer system is running slowly and RAM is near full capacity , the operating system will convert storage space on the drive into temporary memory . This virtual memory slows the system down because it takes longer to access the drive than it does to manage RAM. Transferring data between RAM and virtual memory is called paging . Q uesto's Q uestions 1.3 - Primary Storage (Memory): 1. Describe the differences between primary and secondary storage . This could be done in a table with the column headings 'access speed' , 'storage size' and 'also known as' . [ 6 ] 2. Explain the difference between volatile and non-volatile storage . State an example of both types. [ 4 ] 3. For each type of memory below, describe it and state what information is stored within it: a . Random Access Memory (RAM) [3 ] b. Read-Only Memory (ROM) [ 3 ] c. Cache memory [ 3 ] d. Flash memory [ 3 ] e. Virtual memory [ 3 ] 1.2 - FDE Cycle 1.4 - Secondary Storage Theory Topics

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