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Learn about the three data states - at rest, in transit (in motion) and in use. Resources based on Unit F161 (Developing Application Software) for the OCR Cambridge Advanced Nationals in Computing (H029 / H129) AAQ (Alternative Academic Qualification). Qualification: Cambridge Advanced Nationals in Computing (AAQ) Certificate: Computing: Application Development (H029 / H129) Unit: F161: Developing Application Software 2.3 - Data States Watch on YouTube : Data States You need to understand the characteristics and uses of the three data states (at rest , in transit (in motion) and in use ) What You Need to Know Data States ? YouTube video uploading soon Q uesto's Q uestions 2.3 - Data States: 1. What? [2 ] 2. What? [1 ] 3. What? [1 ] 4. What? [1 ] ? D id Y ou K now? 2.2 - Data Flow Topic List 3.1 - APIs

Learn about different categories of computer systems that can be used to access information including handheld, fixed and shared devices. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification for Unit 2 (Global Information). 1.3 - Access & Storage Devices Exam Board: OCR Specification: 2016 - Unit 2 Handheld Devices Examples of handheld devices: Handheld devices are small, light and possibly can be worn on the human body. These devices are very portable and easy to transport but their small size restricts the space for a powerful processor or high memory capacity. Handheld devices are becoming more powerful over time with extra features, storage options and network connectivity. Advantages: Light and portable so they can be easily carried on a person or in a pocket . Runs on battery power so do not need to be plugged into a power source (unless to charge) allowing for freedom of movement . Disadvantages: Low processing power due to small size and no cooling system . Relies on battery power which may not last for long. More likely to be lost, damaged or stolen . Generally small memory / storage capacity and low versatility . Smartphone Small Tablet eReader Smartwatch Portable Devices Examples of portable devices: Portable devices are larger and more powerful than handheld devices and can be carried easily in a bag. Laptops and larger tablets are the main examples of portable devices. Advantages: Light and portable so they can be easily transported in a laptop bag or small rucksack. Runs on battery power so they can work without a power outlet , such as to complete work on a train or in a library. More powerful and versatile than handheld devices. Disadvantages: Lower processing power and smaller memory / storage capacity than fixed devices like desktops. Reliant on their battery power which may only be a few hours. Laptop Large Tablet Fixed Devices Examples of fixed devices: Fixed devices are bulky devices that require a constant power connection . The most common example of a fixed device is a desktop computer which has a higher processing power and storage capacity than handheld and portable devices. Advantages: Desktop computers have the highest processing power of commercially available home / work computers and contain sufficient cooling systems to maintain temperature. Desktops and games consoles have large storage capacities and can be upgraded / expanded to even larger sizes. Desktop computers are very versatile and are powerful enough to be used for thousands of different purposes, from basic word processing and web browsing to server roles and data mining. Disadvantages: Reliant on a power outlet and cannot be transported whilst on. Heavy and difficult to move . May require additional components like a monitor. Typically more expensive than handheld and portable devices. Desktop Games Console Smart TV Shared Devices A shared device allows multiple users to access data at the same time . Cloud storage is the most common example of a shared device and is used by individuals, schools and businesses around the world through services such as Google Drive, Apple's iCloud and Microsoft's One Drive. A data centre is a dedicated building that contains computer systems - Facebook uses data centres across the globe so that their social media service can be available to users every second of the day. Database servers were explained in Unit 1 section 3.1 . Advantages: A ccessible by multiple users at the same time . For example, the database server can be accessed by employees of a bank simultaneously. Data centres allow online services to run all hours of the day and year . For example, Google uses data centres across the world to ensure their services can be accessed all of the time. Cloud storage frees up physical space for users as the storage is located (usually) on third-party servers. Cloud storage devices allow authorised users such as clients or staff members to access information or work remotely (outside of the office). Disadvantages: Shared devices are reliant on stable network connections . If a connection is lost, access to the device will be affected . Setting up shared devices within an organisation requires technical knowledge , especially for companies establishing their own cloud storage or data centre. Examples of shared devices: Cloud Storage Data Centre Database Server Q uesto's Q uestions 1.3 - Access & Storage Devices: 1. Identify the type of device that the following devices fit into: a. Laptop b. Cloud storage c. Desktop computer d. Smartphone [4 ] 2. Describe the advantages and disadvantages of using each of the 4 types of storage devices. a. Handheld devices [6 ] b. Portable devices [6 ] c. Fixed devices [6 ] d. Shared devices [6 ] 3. For the following scenarios explain which specific device (not type) which would be suitable. You must also justify your choice . a. Working on a spreadsheet on a train before work. [4 ] b. Taking a video of a penalty in a football match to upload to Twitter. [4 ] c. Working on a file with team members located across the country. [4 ] d. Playing Civilization VI on highest settings whilst listening to rock climbing podcasts in a separate tab. [4 ] 1.2 - Storage Media Topic List 1.4 - Internet Connections

Learn how to easily embed a video from YouTube into an HTML web page. 8. Videos HTML Guide Watch on YouTube: Embedding a video from YouTube into your web page is very easy. YouTube Videos Find an appropriate video on YouTube and click the Share button underneath the video. Next, click the Embed option. Embed a video onto your web page. Copy the HTML code that is displayed on your screen and paste it directly into your HTML document. Next you can customise your web page with a background colour and different font styles. 7. Head Tags HTML Guide 9. Colours & Fonts

Learn about 11 key attributes that a respected and successful member of staff should develop in a work environment. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 4.3 - Personal Attributes Exam Board: OCR Specification: 2016 - Unit 1 Any employee in an organisation must demonstrate positive qualities that makes them a useful worker . The following are some of the key attributes that a successful employee of an IT organisation should have. Self-motivation: Workers must be able to motivate themselves to produce high-quality work . They must arrive to work willing to face new challenges and retain a good attitude even when faced with difficulties. Leadership: Managers must show good leadership skills by respecting members of their team so that they are motivated and produce good work. A leader must delegate tasks and take responsibility for negative outcomes. Respect: Respect must be shown at all times to other members of staff and to customers . Employees should be polite and patient when dealing with requests and uphold the company's values . Dependability: Managers must be able to depend on their employees to complete work to the best of their ability and complete it on time . Employees should also be trustworthy and reliable to work on tasks independently. Punctuality: Arriving to work on time is important and shows a commitment to your job . Employees must show up on time to meetings and scheduled events so they don't miss out or upset others. Problem Solving: An employee must be able to look at a problem from different angles and perspectives in order to solve it. Workers must use logic and learn from previous mistakes . Determination: Workers should be focused on their job role and not give up on challenging tasks. Workers must be prepared to work on a dedicated task until it is fully completed . Independence: Workers should be able to work alone on tasks and not rely on other members of staff . They should be confident in finding a solution to a problem independently. Time Management: Most tasks will have a deadline and it is the worker or team's responsibility to ensure all work is completed before that date. Workers must be organised and plan ahead in case of unforeseen circumstances. Team Working: Most modern IT jobs involve group work , either within the office or using online communication across different sites. Workers must cooperate with their peers, share ideas and work together to complete tasks on time. Numerical Skills: Maths skills are required in IT jobs to ensure that jobs are completed accurately and within the budget . Workers may use calculators or spreadsheets to prevent mistakes. Verbal Skills: Spoken communication is a huge part of most jobs, whether that be face-to-face , on the phone or through video calls . Workers must be polite to customers and respectful to co-workers , using appropriate language at all times. Planning & Organisation: To ensure all deadlines are met , teams must carefully plan who will complete each task and by when. Companies must be well organised so that departments can work together and share information when necessary. Q uesto's Q uestions 4.3 - Personal Attributes: The Job Roles section (4.5 ) may help you answer these questions. 1. A games company are looking to hire a new manager to oversee the development of their next video game. Describe 4 personal attributes that the manager should have. [10 ] 2. A software company that develops web browsers is hiring a new programmer . Describe 4 personal attributes that the programmer should have. You must not describe the same attributes as Q1 . [10 ] 3. An animator is required at a large design and movie production studio. Describe 4 personal attributes that the animator should have. You must not describe the same attributes as Q1 or Q2 . [10 ] 4.2 - Communication Technology Topic List 4.4 - Ready for Work

Learn about different types of human computer interaction (HCI) such as audio, movement / gesture, touch and visual (command line and graphical user interface (GUI)). 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) 5.1.1 - Types of Human-Computer Interaction Watch on YouTube : Human-Computer Interaction Human-computer interaction (HCI) refers to the ways in which users engage with computers and is an important factor that must be considered when designing and developing an application . For each type of HCI you need to know its purpose , devices on which it is used , its advantages and disadvantages and how client requirements may affect its use . Human-Computer Interaction Types of User Interaction Audio allows users to interact with a system using voice commands . Body movements or gestures (e.g. hand waves or head turns ) can control or interact with applications . Touch allows users to interact by tapping , swiping , dragging or pinching directly on a screen . Graphical user interfaces ( GUIs ) provide a visual interface using windows , icons , buttons and menus . Command-line interfaces ( CLIs ) only allow interaction with the system by typing text commands into a terminal or shell . Q uesto's Q uestions 5.1.1 - Types of Human-Computer Interaction: 1. A company selling toys wants to create an app to advertise its latest products . Justify the suitability of each user interaction type for the company's app . [5 ] 2. Compare the GUI and CLI visual interaction methods, including their advantages and disadvantages . [8 ] 3. Explain when the audio interaction method would be appropriate . [ 3 ] In 2012 Milwaukee County Zoo started giving iPads to orangutans so they could use the touchscreen to draw pictures . D id Y ou K now? 4.3 - Decomposition Methods Topic List 5.1.2 - Types of Device

Learn about searching algorithms such as linear and binary search. Also learn about sorting algorithms such as merge, bubble and insertion sorts. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.3: Searching & Sorting Algorithms Exam Board: OCR Specification: J277 Watch on YouTube : Linear Search Binary Search Bubble Sort Merge Sort Insertion Sort Key features of a bubble sort: Uses an outer while loop (condition controlled ) to check no swaps have been made . Uses an inner for loop (count controlled ) to repeat through the length of the data set . Uses a flag (a Boolean value ) to track if a swap has been made and uses a temporary value to help correctly swap elements . Linear Search A linear search is the most simple search algorithm. Each data item is searched in order from the first value to the last as if they were all laid out in a line . The list does not have to be in any order before it is searched . This search is also known as a sequential search because the list is searched in a sequence from start to end. For large lists , this search is not very efficient . Binary Search A binary search is a much more efficient searching algorithm as it generally searches through fewer data and is often much quicker - especially for large data sets . In a binary search, the middle point of the data is selected with each iteration and compared to the value being searched for . When the midpoint matches the target value , it as been found and the search can stop. ! ! However there is a prerequisite of using a binary search - the list of data must already be sorted . A prerequisite is a condition that must be satisfied before an algorithm will work correctly . Merge Sort Merge sort is a sorting algorithm based on the idea of ‘divide and conquer ’. A merge sort divides a list into half , again and again until each data item is separate . Then the items are combined in the same way as they were divided , but now in the correct order . When the individual lists are all merged together as one list again, then the data is in order and the algorithm will end . Bubble Sort This algorithm is based on the comparison of adjacent data elements . Data elements are swapped if they are not in the correct order . The algorithm will only stop when a complete iteration through the data is completed with no swaps made . A bubble sort is not suitable for large sets of data . Insertion Sort The list is logically split into sorted values (on the left) and unsorted values (on the right). Starting from the left, values from the unsorted part are checked and inserted at the correct position in the sorted part. This continues through all elements of the list until the last item is reached, and sorted. Insertion sorts are efficient for small data sets but would be slow to sort large sets , compared to alternatives such as a merge sort. Key features of a linear search: A loop is used to check the first value in a list and increment by 1 , checking each value for a match to the target . Reaching the last element of the list without finding a match means the value is not included . Key features of a binary search: A midpoint , lowpoint and highpoint are calculated . A while loop is used to repeatedly compare the midpoint to a target value . The upper half or lower half of the data is ignored if the midpoint does not equal the target . Key features of a merge sort: This algorithm calls itself from within the subroutine (this is known as a recursive algorithm ). It continually splits sublists into a left side and a right side until each sublist has a length of 1 . Watch on YouTube Watch on YouTube Watch on YouTube Watch on YouTube Key features of a insertion sort: Uses an outer for loop (count controlled ) to iterate through each value in the list . Uses an inner while loop (condition controlled ) to find the current value’s correct position in the sorted part of the list . An insertion sort moves ‘ backwards ’ to find the correct position of each value, by decreasing the index within the while loop. Watch on YouTube Q uesto's Q uestions 1.3 - Searching & Sorting Algorithms: Linear Search Explain step-by-step how the number 8 would be found in the following list using a linear search : 12, 5, 3, 2, 8, 19, 14, 6 [4 ] Binary Search Explain step-by-step how the number 2 would be found in the following list using a binary search : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 [6 ] Merge Sort Explain step-by-step how a merge sort would sort the following list of numbers: 4, 8, 5, 1, 3, 6, 7, 2 [6 ] Bubble Sort Explain step-by-step how a bubble sort would sort the following list of numbers: 3, 1, 6, 5, 2, 4 [6 ] Insertion Sort Explain step-by-step how an insertion sort would sort the following list of numbers: 5, 2, 6, 3, 1, 4 [6 ] 1.2 - Designing Algorithms Theory Topics 2.1 - Programming Fundamentals

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 . NOT (negation ) (¬ ) reverses the input value - 1 becomes 0 and 0 becomes 1 . AND (conjunction ) (∧ ) outputs 1 only if both inputs are 1 (e.g. 1 AND 1 = 1 , otherwise 0 ). OR (disjunction ) (v ) outputs 1 if at least one input is 1 (e.g. 1 OR 0 = 1 ). XOR (exclusive disjunction ) (v ) outputs 1 only if one input is 1 but not both (e.g. 1 XOR 1 = 0 , 1 XOR 0 = 1 ). YouTube video uploading soon 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 , where adjacent cells differ by only one bit (following Gray code order ). 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 . YouTube video uploading soon 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 CLK (clock ), 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

Learn about programming constructs such as sequence, iteration and branching, recursion, local and global variables, modularity, functions and procedures, parameter passing by value and by reference, Integrated Development Environment (IDE) tools and object-oriented techniques. Based on the OCR H446 Computer Science A-Level specification. Exam Board: OCR A-Level Specification: Computer Science H446 2.1 - Programming Techniques Watch on YouTube : Programming constructs Recursion Local & global variables Modularity Integrated development environment Object-oriented programming Programming Constructs Sequence , iteration and branching (also called selection ) are the three fundamental programming constructs used to build algorithms . Sequence means that instructions run in a specific order , one after another. Iteration is the repetition of a set of instructions , usually being count-controlled , such as for loops , or condition-controlled , such as while loops or do until loops . Branching (selection ) allows a program to choose between different actions based on a condition , using structures like if , elif , else or switch . YouTube video uploading soon Recursion Recursion is where a function calls itself to solve a problem by breaking it down into smaller , simpler versions of the same problem . Recursion is often used for tasks that naturally fit a 'divide and conquer ' structure , such as quicksort and merge sort algorithms. It is also used for depth-first tree traversals and solving mathematical problems like factorials or the Fibonacci sequence . Compared to iteration , recursion can produce clearer and more elegant solutions , but it may use more memory and can be less efficient if the recursion goes too deep or lacks a proper base case (stopping condition ) , potentially running out of memory . YouTube video uploading soon Local & Global Variables Local variables are created inside a function or block and can only be accessed there , which makes programs safer and easier to debug because changes to the variable cannot affect other parts of the program ; however, they cannot store values that need to be shared across multiple functions . Global variables are declared outside all functions and can be accessed anywhere in the program , making them useful for storing information that many parts of the program need , but they can lead to errors if different functions accidentally change them and can make the program harder to maintain . YouTube video uploading soon Modularity Modularity is the practice of breaking a program into smaller , self-contained parts so each section can be developed , tested and understood independently . Functions and procedures are modular units of code: a function returns a value , while a procedure performs a task without returning a value . When data is passed into a subroutine , it can be passed by value , where a copy of the data is sent so the original cannot be changed , or passed by reference , where the subroutine receives direct access to the original data , allowing it to be modified . YouTube video uploading soon Integrated Development Environment An Integrated Development Environment (IDE ) is software that provides the tools a programmer needs to write , test and debug code in one place . It typically includes an editor for writing and formatting code , syntax highlighting to make keywords and errors easier to spot , and auto-completion to speed up coding . For debugging , an IDE often provides error diagnostics that highlight mistakes , a run-time environment to execute the program , and tools like breakpoints and step-through execution that allow the programmer to pause the program and inspect variables to find and fix bugs more easily . YouTube video uploading soon Object-Oriented Programming Object-oriented techniques are a way of designing programs by modelling them as collections of objects , each representing something with its own data and behaviours . These objects are created from classes , which act like blueprints describing the attributes (data ) and methods (actions ) an object will have . It uses key principles such as encapsulation (keeping an object’s data and methods together and protected ), inheritance (allowing classes to share and reuse features ) and polymorphism (enabling objects to behave differently ). These techniques make large programs easier to organise , maintain and extend by encouraging reusable , modular and well-structured code . YouTube video uploading soon This page is under active development. Check here for the latest progress update. Q uesto's K ey T erms Programming Constructs: sequence, iteration, selection (branching), if / elif / else, select (switch) case Recursion & Iteration: count-controlled loop, condition-controlled loop, recursion, base case Variables: local variable, global variable Modularity: function, procedure, parameter, pass by value, pass by reference Integrated Development Environment (IDE) Object Oriented Programming (OOP): class, object, method, attribute, inheritance, encapsulation, polymorphism D id Y ou K now? Roblox Studio is a free IDE for making Roblox games using the programming language Lua . With over 70m daily Roblox players , games built in Roblox Studio can reach a larger audience than many mainstream game engines . 1.1 - Computational Thinking A-Level Topics 2.2 - Computational Methods

Learn about different methods of wired and wireless connection methods including Bluetooth, satellite and microwave. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.4 - Connectivity Exam Board: OCR Specification: 2016 - Unit 1 For computers to communicate with other devices and share data a form of connection is required. Wired Connections Copper Cables Copper cables are a cheaper type of wired internet connection that may be poorly insulated and therefore susceptible to electromagnetic interference . Copper cables are more likely to suffer from attenuation (network distortion ). However, they are malleable (easier to bend) and less likely to break than other cables such as fibre optic. They have a lower bandwidth - cannot transmit as much data at once - than fibre optic cables. Fibre Optic Cables Fibre optic cables are a very fast but expensive type of wired internet connection. Signals are transmitted as waves of light through a glass rod . Because of this fibre optic cables are not affected by electromagnetic interference and suffer less from attenuation . Fibre optic cables have a higher bandwidth - they can transfer more data at one time over a long distance than copper cables but they are more fragile . Wireless Connections Bluetooth Bluetooth is a temporary short-range communication between two 'paired ' devices within a limit of about 10 metres . The required close proximity is a disadvantage , however a plus is that no other hardware is required for a connection. An example is the pairing of headphones to a smartphone to listen to music. Infrared Infrared networks have largely been replaced by Bluetooth or WiFi connections because infrared networks require devices to be in direct line of sight . Infrared is still used by some devices, such as remote controls , to transmit signals to a TV, but it only works across short distances . Microwave Microwave connections use radio waves to send signals across a large area via microwave towers . It can transmit a large amount of data but antennas must be in the line of sight of each other with no obstructions . Microwave connections are affected by bad weather , leading to higher chances of attenuation (network distortion ). Laser Satellite GSM / 5G Although not common, laser connections can send data between devices that are in the line of sight of each other as long as there are no barriers . Laser connections can transmit data up to 2km but bad weather severely affects the transmission rate. Laser connections can be used in space as there are fewer barriers between the satellites. Satellite networks use point-to-multipoint communication by using satellites above the Earth's atmosphere that receive a transmission and rebroadcast them back to Earth. Because of the distance between the communication device and the satellite (roughly 35,000km), there is a delay between data transmission and it being received. See 3.4 for more information on satellite networks . GSM (Global System for Mobile communications ) is a technology for allowing mobile phones to connect to a network for calls and text messages. Advances in mobile technology are classified by generations such as 4G and 5G (the current generation). Each generation is generally faster, more secure and allows for new opportunities. See 3.4 for more information on cellular networks . Q uesto's Q uestions 1.4 - Connection Methods: 1. Compare the differences between copper and fibre optic cables (possibly in a table) by the following features: a. Price b. Bandwidth c. Inteference d. Attenuation e. Malleability / Fragility [2 each ] 2. Describe each of the different types of wireless connection . Try to list 1 advantage and 1 disadvantage of using each type. a. Bluetooth b. Infrared c. Microwave d. Laser e. Satellite f. GSM / 5G [5 each ] 1.3 - Computer System Types Topic List 1.5 - Communication Hardware

Learn about different data structures such as arrays, lists and records. Also, the difference between static and dynamic data structures and how to design files. Based on the 2020 Eduqas (WJEC) GCSE specification. 5.1: Data Structures & File Design Exam Board: Eduqas Specification: 2020 What is a Data Structure? A data structure is a way of efficiently organising data . There are two general forms of data structures: Static Data Structures The size of a static data structure cannot change e.g. if a data structure has 20 elements, no additional elements can be added or removed. The values of the data elements can be changed, but memory size is fixed when allocated at compile time. Because a static data structure holds a certain number of data elements they are easier to program because the size of the structure and the number of elements never change. An array is an example of a static data structure. Examples: A static data structure could be an array of teams in the Premier League. The data elements will change each year when teams are relegated and promoted but there will always be 20 teams. Dynamic Data Structures The size of a dynamic data structure can change as the program is being run , it is possible to add or remove data elements. Dynamic data structures make the most efficient use of memory but are more difficult to program , as you have to check the size of the data structure and the location of the data items each time you use the data. A list is an example of a dynamic data structure. A dynamic data structure could be a list of all teams in the Premier League that won their last match. Data elements (teams) will be added or removed across the season. Types of Data Structures List A list is a dynamic data structure that has the data elements stored in the order they were originally added to memory . Every data structure starts at 0, not 1 . Lists store data elements in the order they were added, so the first doctor is 0 and the most recent doctor is 12. An example list of the main Doctor Who actors Array An array is a static data structure that can hold a fixed number of data elements . Each data element must be of the same data type i.e. real, integer, string. The elements in an array are identified by a number that indicates their position in the array. This number is known as the index. The first element in an array always has an index of 0 . You should know how to write pseudo code that manipulates arrays to traverse, add, remove and search data. The following steps uses Python as an example. Traversing an Array To traverse (' move through ') an array a for loop can be used to display each data element in order. 'Inserting' a value In an array the size is fixed so you cannot insert new values, but you can change the value of elements that already exist. Overwriting the fourth element (Daphne) with a new value (Laura) will change it from Daphne to Laura. Example code for traversing: Example code for inserting: Output: Output: 'Deleting' a value In an array the size is fixed so you cannot delete values, but you can overwrite them as blank . Overwriting the second element (Shaggy) with a blank space makes it appear deleted. Example code for deleting: Output: Searching an Array Example code for searching: For large arrays a for loop is needed to search through each element for a specific value . This example checks each name to see if it is equal to Velma. Output: Two-Dimensional Array Often the data we want to process comes in the form of a table . The data in a two dimensional array must still all be of the same data type , but can have multiple rows and columns . The two-dimensional array to the right shows the characters from Scooby Doo along with their associated colour and their species. Each value in the array is represented by an index still, but now the index has two values . For example [3] [0] is 'Daphne'. We measure row first , then column . Searching a two-dimensional array: To print a specific data element you can just use the index number like Daphne above. To search for a specific value you will need two for loops, one for the row and another for the values of each row. The example to the right is looking for the value of 'Velma' and when it is round it prints the associated data from the whole row. Example code for printing: Output: Example code for searching: Output: Records Unlike arrays, records can store data of different data types . Each record is made up of information about one person or thing. Each piece of information in the record is called a field (each row name). Records should have a key field - this is unique data that identifies each record . For example Student ID is a good key field for a record on students as no two students can have the same Student ID. Data files are made up of records with the same structure. It would be most efficient for the fields in a record to be stored next to each other so that the data can be read into the record data structure in memory for processing by the CPU. In an exam you may be asked to state and design a data structure for a given scenario. If the data structure can hold values of the same data type you should draw an array , usually a 2D array for multiple rows and columns. Remember that a record is required to store values of different data types . Example questions: "A video gamer has recorded their three lap times in four Mario Kart courses." " State and design the most suitable data structure for this data." A two-dimensional array is most suitable because only one data type ( real ) is stored. "A vet surgery stores data on all dogs and cats including the animal's name, age (in years), weight (in kg) and whether or not it has been vaccinated." " State and design the most suitable data structure for this data for four animals ." A record is most suitable because the data structure requires different data types . Q uesto's Q uestions 5.1 - Data Structures: 1. Give two differences between static and dynamic data structures . [ 4 ] 2. Describe the differences between a list , array and record . [ 3 ] 3. A one-dimensional array looks like this: TigerBreeds("Sumatran","Indian","Malayan,"Amur") Write the code to: a. Print the element with the index of 3. [ 2 ] b. Change Indian to South China. [ 2 ] c. Remove the Amur element. [ 2 ] d. Search through the array for 'Malayan'. [ 2 ] 4. State and design the most suitable data structure for these scenarios: a. For each book in a bookshop, the staff need to record the title, author, number of pages and whether or not it is a signed copy. Include data for three books. [ 3 ] b. Four dieters are recording how many kilograms they have lost each month for 5 months. [ 4 ] 5. Design a file that stores the first initial, surname, age and hair colour of each member of a family. [ 8 ] Designing Data Structures Data is stored in files when it needs to be kept after the program has stopped running . To learn how to write code for file handling (e.g. opening, writing to, reading from and closing files) in Python click here . Designing a file requires more than just the field name (e.g. Name) and data values (e.g. Rebecca). The data type (e.g. string) and any validation checks (e.g. format check) should also be considered. Below is an example file design for a bakery. Designing Files 4.8 Compression Theory Topics 6.1 - Operating Systems

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 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