Learn about boolean logic and expressions using NOT, AND OR and XOR, Karnaugh maps, Boolean algebra rules including De Morgan’s Laws, distribution, association, commutation and double negation, logic gate diagrams, truth tables, D-type flip flops, half adders and full adders. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 4.3 - Boolean Algebra Watch on YouTube : Boolean Logic (NOT, AND, OR, XOR) Karnaugh maps Boolean algebra rules Logic gate diagrams Truth tables D-type flip flops Half & full adders This topic explores how the logical operations NOT , AND , OR and XOR are used to process binary data and control digital systems . It also looks at how to simplify and represent logic using Karnaugh maps , Boolean algebra rules , logic gate diagrams and truth tables . Boolean Logic Boolean logic is a form of algebra in which all values are either True (1 ) or False (0 ). It’s used in computing and digital circuits to make decisions and control the flow of programs . There are four Boolean operators to know: NOT (¬ ) reverses the input value - 1 becomes 0 and 0 becomes 1 . AND (∧ ) outputs 1 only if both inputs are 1 (e.g. 1 AND 1 = 1 , otherwise 0 ). OR (∨ ) outputs 1 if at least one input is 1 (e.g. 1 OR 0 = 1 ). XOR (v ) outputs 1 only if one input is 1 but not both (e.g. 1 XOR 1 = 0 , 1 XOR 0 = 1 ). Karnaugh Maps A Karnaugh map is a visual method used to simplify Boolean expressions and make logic circuits more efficient . It organises all possible input combinations into a grid , to more easily identify an expression's simplest form . By grouping together 1s (representing True outputs ) in powers of two (1 , 2 , 4 or 8 cells ), you can identify and remove redundant terms in a Boolean expression . The simplified result reduces the number of logic gates needed in a circuit, making it faster and easier to build . Boolean Algebra Rules Boolean algebra rules are used to simplify Boolean expressions . De Morgan’s Laws show how to distribute negation across AND and OR operations: ¬(A AND B) = (¬A OR ¬B) and ¬(A OR B) = (¬A AND ¬B) . Distributive Law allows expressions to be expanded or factored , e.g., A AND (B OR C) = (A AND B) OR (A AND C) and vice versa for OR over AND. Associative Law means the grouping of terms doesn’t affect the result . (A AND B) AND C = A AND (B AND C) and (A OR B) OR C = A OR (B OR C) . Commutative Law means the order of terms doesn’t matter in Boolean operations, e.g., A AND B = B AND A and A OR B = B OR A . With Double Negation , two NOTs cancel each other out , returning the original value , e.g., ¬¬A = A . YouTube video uploading soon Logic Gate Diagrams Logic gate diagrams are visual representations of Boolean expressions or digital circuits , showing how data flows through logic gates to produce an output . Each gate performs a basic logical operation (such as NOT , AND , OR or XOR ) and is represented by a distinct symbol . NOT AND OR XOR YouTube video uploading soon Truth Tables A truth table is used to show all possible input combinations for a logic circuit or Boolean expression , along with the resulting output for each combination . Each row in the table represents a unique set of input values (usually 0 for False and 1 for True ). The final column shows the output produced by applying the logical operations to those inputs . The number of rows in a truth table doubles with each additional input , e.g. 4 rows for 2 inputs and 8 rows for 3 inputs . YouTube video uploading soon D-Type Flip Flops A D-type flip-flop i s a sequential logic circuit that stores a single bit of data (either 0 or 1 ). It has two inputs - D (data ) and C lock - and two outputs - Q and ¬Q . When a clock pulse occurs , the flip-flop copies the value of D to the Q output , and that value is held (stored ) until the next clock pulse . This makes D-type flip-flops useful for memory storage , registers and data synchronisation . Essentially, they act as a 1-bit memory cell , storing the last value of D whenever the clock signal triggers . YouTube video uploading soon Half Adders & Full Adders A half adder is a logic circuit with two inputs (A and B ) that are added to produce two outputs - S (sum ), the result of A XOR B - and C (carry ), the result of A AND B . Half adders can only add two bits and cannot handle an input carry from a previous addition . A full adder is an extension of a half adder with three inputs : A , B , and C in (a carry-in from a previous calculation ). It produces two outputs : S (sum ) (A XOR B XOR Cin ) and C out (carry out ) ((A AND B) OR (B AND Cin) OR (A AND Cin) ). Full adders can be linked together to perform multi-bit binary addition in arithmetic circuits. YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Boolean Logic: NOT, AND, OR, XOR, Karnaugh maps, logic gate diagrams, truth tables Boolean Algebra Rules: De Morgan’s Laws, distribution, association, commutation, double negation D-Type Flip Flops: data, clock, Q, NOT Q Adders: half adder, full adder D id Y ou K now? The word ' Boolean ' is always spelt with a capital B because it is named after George Boole , a 19th-century English mathematician . His work has become the foundation of all modern digital electronics and computing . 4.2 - Data Structures A-Level Topics 5.1 - Computing Legislation

Homepage for learning about computer science in school. Discover topics across GCSE and Level 3 IT subjects, plus programming languages including Python, HTML and Greenfoot. C omputer S cience Newb ie s Popular topics: Python Programming Learn how to program in Python, with examples and challenges to test your skills. OCR GCSE ( J277 ) Covers all content from both papers of the current Cambridge OCR GCSE specification. OCR A-Level ( H446 ) Covers all content from both papers of the current Cambridge OCR A-Level spec. Application Development Cambridge Advanced National In Computing resources for Units F160 and F161. Latest YouTube Video Latest Blog Post Links & Information You are viewing the mobile version of CSNewbs. The site will appear better on a desktop or laptop . YouTube Channel Last updated: Millions of visits since 2017! About CSNewbs - Support CSNewbs - 800,000+ views - Tuesday 8th September 2026

Learn about the components of the Central Processing Unit (CPU) and Von Neumann architecture. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). Exam Board: Cambridge OCR 1.1a: The CPU Specification: GCSE - J277 Watch on YouTube : The CPU The function of each CPU component : Control Unit (CU ) Arithmetic Logic Unit (ALU ) Registers Cache What Von Neumann architecture is. What You Need to Know The Central Processing Unit The Central Processing Unit ( CPU ) is the most important component in any computer system. Like many computer components, it is attached to the motherboard . The purpose of the CPU is to process data and instructions by constantly repeating the fetch-execute cycle . CPU Components The Control Unit (CU ) sends signals to control hardware and coordinate the flow of data inside the CPU and across the computer . It also decodes instructions as part of the fetch-execute cycle . The Arithmetic Logic Unit (ALU ) performs mathematical calculations , logical operations and binary shifts . The results of calculations made by the ALU are stored in a register called the accumulator . A register is a temporary storage space for one piece of data , instruction or address . Different registers are used during the fetch-execute cycle . Cache memory stores frequently accessed data and instructions because it is much faster for the CPU to access (fetch from) than RAM . Computer Architecture The way a computer is designed and structured is known as its architecture . A common type of computer architecture is Von Neumann (pronounced Von Noy-man), named after mathematician John Von Neumann . Von Neumann Architecture Instruction Data RAM ADD 53 A computer with Von Neumann architecture stores both program instructions and data in the same memory (RAM ). This is different from other architectures that have an instruction memory and a separate data memory . Instructions (technically called the opcode ) and data (technically called the operand ) are not the same . An instruction is an action to perform and data is the value to be used. For example with the command 'ADD 43 ', ADD is the instruction and 43 is the data . Von Neumann architecture also contains the key CPU components of a control unit , arithmetic logic unit (ALU ), registers and cache memory . Q uesto's Q uestions 1.1a - The CPU: 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] 2. Draw a diagram of the CPU , and l abel the four main components . [ 4 ] 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] d. Cache memory [ 2 ] 4a. Describe the key feature of Von Neumann architecture . [ 2 ] 4b. Explain how an instruction is different to data . [ 2 ] 1.1b - Fetch-Execute Cycle Theory Topics

Learn about key registers used in the fetch - execute cycle such as the program counter and current instruction register. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.1b: The Fetch-Execute Cycle Exam Board: Cambridge OCR Specification: GCSE - J277 Watch on YouTube : The Fetch Execute Cycle The purpose of the Central Processing Unit (CPU ). The actions that occur at each stage of the fetch-execute cycle and how CPU components are used in the cycle. The purpose of each register (PC , MAR , MDR and ACC ) and what they store . The difference between data and an address . What You Need to Know The Fetch-Execute Cycle The purpose of the Central Processing Unit (CPU ) is to process data and execute instructions by constantly performing the fetch-execute cycle . Fetch Stage Execute Stage In the fetch stage , instructions are fetched from RAM and transferred into the registers inside the CPU . It is the Memory Data Register (MDR ) specifically that a fetched instruction is stored in. In the execute stage , instructions are decoded by the control unit and then executed (run). Any mathematical calculations are performed by the Arithmetic Logic Unit (ALU ) and the results are stored in a register called the Accumulator (ACC ). RAM CPU Control Unit ALU ACC Registers A register is a small storage space for a temporary piece of data , instruction or address in the CPU . Each register has a specific role . There are four essential registers used in the fetch-execute cycle : The Memory Address Register ( MAR ) stores the address of the current instruction to be fetched from RAM , once it has been copied from the PC. The Memory Data Register ( MDR ) stores the instruction fetched from the memory location identified by the MAR . The Program Counter (PC ) stores the address of the next instruction to be fetched from RAM . The address from the PC is copied into the Memory Address Register (MAR ). The PC is then incremented by 1 because it always shows the address of the next instruction . The results of any executions , such as calculations made by the ALU , are stored in the Accumulator ( ACC ). The PC , MAR and MDR are used in the fetch stage , whereas the ACC is used in the execute stage . The PC and MAR store an address (a memory location in RAM ) whereas the MDR and ACC store data (a value ). Q uesto's Q uestions 1.1b - The Fetch-Execute Cycle: 1 . What is the purpose of the CPU ? [2 ] 2. Draw a diagram with icons and words to show what happens in the stages of the Fetch-Execute cycle . [ 4 ] 3 . Describe the purpose of each register : a. The Program Counter (PC) [ 2 ] b. The Memory Address Register (MAR) [ 2 ] c. The Memory Data Register (MDR) [ 2 ] d. The Accumulator (ACC) [ 2 ] 1.1a - The CPU Theory Topics 1.2 - CPU Performance

Learn about what embedded systems are and examples of them. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.3: Embedded Systems Exam Board: Cambridge OCR Specification: GCSE - J277 Watch on YouTube : Embedded Systems Required knowledge about embedded systems include: What embedded systems are. The characteristics of an embedded system. Examples of embedded systems. What You Need to Know Embedded Systems An embedded system is a computer system built into a larger machine to provide a means of control . They perform specific pre-programmed tasks that are often stored in ROM . Embedded systems typically have dedicated hardware , a small amount of memory and low processing power . Their functions are limited and they may be difficult to update . A washing machine has an embedded system that manages wash cycles and controls water temperature . Modern cars contain embedded systems that manage the engine and automate features such as lights . A traffic light has an embedded system that controls the sequence and timing of the lights . Q uesto's Q uestions 1.3 - Embedded Software: 1a. Define an embedded system in one sentence. [2 ] 1b. Describe three characteristics of an embedded system . [3 ] 2. Give two examples of embedded systems and describe what they control . [ 4 ] 1.2 - CPU Performance 2.1 - Primary Storage Theory Topics

Learn about the three factors that affect computer performance - cache memory, clock speed and the number of cores. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.2: CPU Performance Exam Board: Cambridge OCR Specification: GCSE - J277 Watch on YouTube : CPU Performance How these CPU characteristics affect the performance of a computer system: Clock speed Cache size Number of cores What You Need to Know Clock Speed A computer has a component called a clock , which produces regular electrical pulses . Clock speed is the number of clock pulses the CPU receives per second . It is measured in gigahertz (GHz ). For example, 3.5 GHz is 3.5 billion pulses per second . The Control Unit (CU ) uses each clock pulse to send control signals that coordinate operations within the computer. A higher clock speed improves the performance of the CPU because more fetch-execute cycles can be completed per second . This means more instructions can be executed in the same amount of time , so tasks can be completed faster . Cache Size Cache memory is fast , temporary storage inside (or very close to) the CPU , which stores frequently accessed data and instructions . It is typically split into three levels (L1 , L2 and L3 ), with each level generally being larger but slower than the previous level. As data and instructions are fetched during the fetch-execute cycle , frequently accessed data and instructions can be stored in cache , reducing the need to repeatedly fetch them from RAM, which is slower to access . A CPU with a larger cache can store more frequently accessed data and instructions , improving performance because they can be accessed faster from cache than from RAM . Number of Cores Some CPUs have multiple cores . A core is an individual processing unit within the CPU , containing components such as a control unit , ALU , registers and cache . Each core can independently perform the fetch-execute cycle . A CPU with more cores can have higher performance because it can process more instructions at the same time . However, performance may not improve if one core must wait for another to complete its task . Also, some software is not designed to use multiple cores , so it will not benefit from having additional cores . Single-core Dual-core Quad-core Octa-core Q uesto's Q uestions 1.2 - CPU Performance: Clock Speed 1a. What is clock speed ? What is it measured in? [ 2 ] 1b. Explain how a higher clock speed improves performance . [ 2 ] Cache Size 2a. What is cache memory ? [ 2 ] 2b. Describe why a larger c ache size may mean performance is higher . [ 4 ] Number of Cores 3a. What is a core ? [ 2 ] 3b. Explain why a quad-core processor should have a higher performance than a dual-core processor . [ 3 ] 3c. Explain two reasons why having more cores doesn't necessarily mean the performance will be better . [ 2 ] 1.1b - Fetch-Execute Cycle 1.3 - Embedded Systems Theory Topics

The list of topics in the 2020 OCR GCSE Computer Science specifications. OCR GCSE Computer Science These pages are based on the J277 GCSE Computer Science specification from the Cambridge OCR exam board. Component One: Computer Systems OCR GCSE Key Term Generator Paper 1 Playlist on YouTube 1. Systems Architecture 1.1a - The CPU 1.1b - The Fetch-Execute Cycle 1.2 - CPU Performance 1.3 - Embedded Systems 2. Memory & Storage 2.1 - Primary Storage (Memory) 2.2 - Secondary Storage 2.3 - Units 2.4a - Number Systems 2.4b - Binary Addition & Shifts 2.4c - Character Storage 2.4d - Image Storage 2.4e - Sound Storage 2.5 - Compression 3. Networks 3.1a - Network Types & Performance 3.1b - Network Hardware & Internet 3.2a - Wired & Wireless networks 3.2b - Protocols & Layers 4. Network Security 4.1 - Network Threats 4.2 - Preventing Vulnerabilities 5. Systems Software 5.1 - Operating Systems 5.2 - Utility Software 6. Impacts 6.1a - Impacts of Technology 6.1b - Legislation Component Two: Computational Thinking, Algorithms and Programming Paper 2 Playlist on YouTube 1. Algorithms 1.1 - Computational Thinking 1.2 - Designing Algorithms 1.3 - Searching & Sorting Algorithms 2. Programming Fundamentals 2.1 - Programming Fundamentals 2.2 - Data Types 2.3 - Additional Programming Techniques 3. Producing Robust Programs 3.1 - Defensive Design 3.2 - Testing 4. Boolean Logic 4.1 - Boolean Logic 5. Languages & IDEs 5.1 - Languages & Translators 5.2 - Integrated Development Environment

Learn about six network devices - hub, switch, router, bridge, WAP and NIC. Also, learn about routing tables and cost diagrams. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.4: Network Hardware & Routing Exam Board: Eduqas Specification: 2020 Network Devices Hub A hub receives data packets from a connected device and transfers a copy to all connected nodes . Switch A switch receives data packets , processes them and transfers them on to the device specifically listed in the destination address of the packet. Router Routers are used to transfer data packets between networks . Data is sent from network to network on the internet towards the destination address listed in the data packet. A router stores the address of each computer on the network and uses routing tables to calculate the quickest and shortest path . Bridge A bridge joins together two networks that use the same base protocols . For example, a bridge could link together a LAN to another LAN . Wireless Access Point (WAP) Provides a link between wireless and wired networks . It creates a wireless local area network that allows WiFi enabled devices to connect to a wired network. Network Interface Card (NIC) A Network Interface Card (often shortened to NIC ) is an internal piece of hardware that is required for the computer to connect to a network . It used to be a separate expansion card but now it is commonly built directly into the motherboard (and sometimes known as a network adapter ). Wireless network interface cards ( WNIC ) permit a wireless network connection. Routing A routing table is a list of the optimal routes for data packets to be sent from one device to another. Routing tables should be kept accurate and up to date to ensure that packets are transferred as quickly as possible . During routing the lowest cost route is calculated . This is the shortest path with the fastest nodes to transfer data. Below is a simplified network and basic routing table showing the lowest cost (optimal) route using node A as the source address. Q uesto's Q uestions 3.4 - Network Hardware & Routing: 1a. Describe the difference between a hub and a switch . [ 2 ] 1b. Explain how a modem works. [ 2 ] 1c. Describe the purpose of a router . [ 2 ] 1d. Describe the difference between a gateway and a bridge . [ 2 ] 1e. State what WAP stands for and describe its purpose . [ 2 ] 1f. State what NIC stands for and why it is required . [ 2 ] 2a. Describe what a routing table is and why they should be maintained . [ 2 ] 2b. In terms of routing, what does a low-cost route mean? [ 2 ] 2c. Copy and complete the routing table below using node J as the source address . [ 4 ] 3.3 - Network Topology Theory Topics 3.5 - Protocols

The most common errors made in Grennfoot when making a game and how to fix them, including when missing punctuation is expected or the end of file is reached while parsing. Common Greenfoot Errors Greenfoot Home If the world becomes greyed out and you can't click on anything then an error has occurred. The actor with the error will have red lines on it. When an error occurs, a red squiggly line will appear underneath the problem. Hover your mouse over the line and a helpful message will appear to help you solve the issue. Some of the more common errors (and how to fix them) are listed below: ; expected Every line with a white background must end in a semi colon ( ; ) ) expected You have missed a bracket . Count the number of open brackets and the number of closed brackets on a line and make sure you have an equal number of both. reached end of file while parsing You are missing at least one curly bracket ( } ) at the end of your program . Press enter to move onto a new line at the bottom; you must have a closed curly bracket with a yellow background and another closed curly bracket with a green background . cannot find symbol You have typed a command incorrectly . Greenfoot uses a system where commands have no spaces and each word after the first word is uppercase . Such as isKeyDown not IsKeyDown and not isKeydown. Check your spelling and capitals carefully. Stuck ? If you start typing but can't remember what commands come next, press Ctrl and Space together to show a list of all possible commands that you can use.

Learn about software development methodologies such as the waterfall lifecycle, agile methodologies, extreme programming, the spiral model and rapid application development (RAD). Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level 2.3 - Software Development Specification: Computer Science H446 Watch on YouTube : Waterfall Lifecycle Extreme Programming Spiral Model Rapid Application Development Software development models are step-by-step methods for creating and maintaining software . They are used to keep projects organised , reduce mistakes and make sure the finished program meets the user’s needs . Different models suit different types of projects . Waterfall Lifecycle The waterfall model is a linear and structured approach where each phase is completed one at a time in order . It needs all requirements to be clearly defined at the start , with little to no changes allowed once a phase is finished . This model is best suited for projects with fixed requirements and minimal risk of change . Extreme Programming Extreme Programming ( XP ) is a type of agile methodology that uses an iterative and flexible approach, progressing in small , usable chunks called iterations (or sprints ). It relies on frequent collaboration with stakeholders and user feedback to adapt to changing requirements . This model is ideal for dynamic projects where quick delivery and frequent updates are important. Spiral Model The spiral model combines iterative development and risk management , progressing through repeated cycles of planning , risk assessment , engineering ( development and testing ) and evaluation . Each loop focuses on identifying and addressing risks early in the project. It is ideal for complex and high-risk projects where requirements may change over time . Rapid Application Development The rapid application development ( RAD ) model focuses on quickly building software through iterative development and frequent user feedback . It uses reusable components , time-boxing and constant feedback to speed up the delivery of an effective final product . RAD is best suited for projects that need to be completed quickly and where requirements can evolve during development . Q uesto's K ey T erms Software Development: waterfall lifecycle, agile methodology, extreme programming (XP), spiral model, rapid application development (RAD) D id Y ou K now? Agile development is named after the ' Agile Manifesto ' - a set of principles for software development agreed by a group of developers at a ski resort in Utah , USA in 2001 . 2.2 - Applications Generation A-Level Topics 2.4 - Programming Languages

Learn about the three types of translators - assemblers, interpreters and compilers. Also, understand the differences between compilers and interpreters. Based on the 2020 Eduqas (WJEC) GCSE specification. 10.1: Translators Exam Board: Eduqas Specification: 2020 What is a translator? A translator changes (translates) a program written in one language into another language (usually machine code ). There are three types of translator : Assembler An assembler converts low level assembly language into machine code . INP STA 33 INP STA 34 LDA 33 ADD OUT HLT Interpreter An interpreter converts high-level language one line at a time into machine code and executes it. PYT HON 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 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 Differences between an interpreter and a Compiler: 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 10.1 - Translators: 1. Briefly describe each type of translator : a. Assembler [ 1 ] b. Interpreter [ 2 ] c. Compiler [ 2 ] 2. 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 ] 9.1 - IDE Tools Theory Topics 10.2 - Stages of Compilation

Learn about secondary storage types such as solid-state, magnetic, optical and paper. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 1.2 - Storage Media Exam Board: OCR Specification: 2016 - Unit 2 Data can be stored on a variety of storage media , each with its own benefits and drawbacks . Magnetic Storage Optical Storage A magnetic hard disk drive (HDD ) is the most common form of secondary storage within desktop computers. A read/write head moves nanometres above the disk platter and uses the magnetic field of the platter to read or edit data. Hard disk drives can also be external and connected through a USB port . An obsolete (no longer used) type of magnetic storage is a floppy disk but these have been replaced by solid state devices such as USB sticks which are much faster and have a much higher capacity. Another type of magnetic storage that is still used is magnetic tape . Magnetic tape has a high storage capacity but data has to be accessed in order (serial access ) so it is generally only used by companies to back up or archive large amounts of data . Optical storage uses a laser to project beams of light onto a spinning disc, allowing it to read data from a CD , DVD or Blu-Ray . This makes optical storage the slowest of the four types of secondary storage. Disc drives are traditionally internal but external disc drives can be bought for devices like laptops. Magnetic Storage Characteristics: ✓ - Large CAPACITY and cheaper per gigabyte than solid state . X - Not DURABLE and not very PORTABLE when powered on because moving it can damage the device. ✓ - Relatively quick ACCESS SPEED but slower than Solid State . Optical Storage Characteristics: X - Low CAPACITY : 700 MB (CD ), 4.7 GB (DVD ), 25 GB (Blu-ray ). X - Not DURABLE because discs are very fragile and can break or scratch easily. ✓ - Discs are thin and very PORTABLE . X - Optical discs have the Slowest ACCESS SPEED . Magnetic Disks are spelled with a k and Optical Discs have a c. Solid State Storage Paper Storage There are no moving parts in solid state storage. SSD s (Solid State Drives ) are replacing magnetic HDDs (Hard DIsk Drives) in modern computers and video game consoles because they are generally quieter , faster and use less power . SSDs can also be external . A USB flash drive ( USB stick ) is another type of solid state storage that is used to transport files easily because of its small size. Memory cards , like the SD card in a digital camera or a Micro SD card in a smartphone , are another example of solid state storage. Paper storage includes printed or hand-written documents, notes, forms, schedules and maps. Paper is relatively inexpensive in small quantities but it can take up a lot of space compared to small devices like USB sticks. Producing paper is environmentally damaging and requires physical security methods to keep safe. Paper, such as a timetable, can be written on if times change and easily carried on a person. However, paper in the form of an essay must be re-printed to add changes . Solid State Characteristics: ✓ - High CAPACITY but more expensive per gigabyte than magnetic . ✓ - Usually DURABLE but cheap USB sticks can snap or break . ✓ - The small size of USB sticks and memory cards mean they are very PORTABLE and can fit easily in a bag or pocket. ✓ - Solid State storage has the fastest ACCESS SPEED because they contain no moving parts . Paper Storage Characteristics: X - Low CAPACITY as each page can only hold a certain amount of information. Paper also takes up physical space . X - Poor DURABILITY as paper can easily tear and become damaged in rain. ✓ / X - PORTABILITY varies as single sheets of paper can be easily folded and placed in a pocket. However, large stacks of paper can be difficult and expensive to transport. X - Paper's ACCESS SPEED , in terms of searching for a specific item, is slow , especially if the paper storage has not been organised efficiently . Q uesto's Q uestions 1.2 - Storage Media: 1. State 3 examples of each type of storage media . For example, a CD for optical storage. [3 each ] 2. Compare each type of storage media in terms of capacity , durability , portability and access speed . You may decide to do this as a table or poster. [16 ] 3. Identify the most suitable device (not the media ) and justify its suitability for the following scenarios: a. Backing up a large database at the end of each day. [5 ] b. Keeping a copy of a cleaning schedule for hotel staff. [5 ] c. Making copies of a promotional video to hand out to audience members at a dancing event. [5 ] 1.1 - Holders of Information Topic List 1.3 - Access & Storage Devices