Learn about sorting algorithms - merge and bubble sort - and searching algorithms - linear and bubble search. Based on the 2020 Eduqas (WJEC) GCSE specification. 8.4: Sorting & Searching Algorithms Exam Board: Eduqas Specification: 2020 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 . A bubble sort is not suitable for large sets of data. 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 many data items can be ignored. However, the list of data must already be sorted in order before a binary search can take place. Q uesto's Q uestions 8.3 - 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, 2, 6, 4, 1, 4 [6 ] Watch on YouTube Watch on YouTube Watch on YouTube Watch on YouTube 8.3 - Writing Algorithms Theory Topics 8.5 - Validation & Verification

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

This page contains topics from the 2016 Eduqas / WJEC that are not included in the 2020 Eduqas / WJEC specification. Topics from the 2016 Eduqas Specification This page contains information from the 2016 Eduqas specification that was removed for the 2020 specification. Quick Links: Buses & Instruction Sets (RISC & CISC) Protocols (IMAP & POP3) Network Devices (Gateway) Human-Computer Interaction (Command-Line Interface, Touch-Sensitive Interface, Menu-Driven Interface, Voice-Driven Interface) Cyber Attacks (Dictionary Attack, Buffer Overflow, Human Weakness) Software Protection (Secure by Design, Too Many Permissions, Scripting Restrictions, Validation with Parameters) Data Policies (Acceptable Use Policy, Disaster Recovery, Cookies) Environmental Issues (Tips to Reduce Waste, Positive Impacts of Technology) Object Oriented Programming (Greenfoot and Java) Programming Topics (Assembly Language, HTML, Greenfoot) Buses Buses & Instruction Sets Buses Data is transferred within a computer system along pathways called buses . There are three types of bus: Address Bus Data Bus Control Bus Sends a memory address of where data is stored. The address is sent from the CPU to RAM in the FDE cycle. Transfers data between components. Data is sent both ways . Sends control signals from the control unit to other components of the system. Status signals are sent back to the CPU. An instruction set is a list of all the instructions that a CPU can process as part of the FDE cycle . CPUs can have different sets of instructions that they can perform based on their function. The two most common instruction sets are the simpler RISC (Reduced Instruction Set Computer ) and more complicated CISC (Complex Instruction Set Computer ). Instruction Sets Reduced Instruction Set Computer (RISC) Complex Instruction Set Computer (CISC) Complexity RISC has fewer instructions than CISC and is therefore slower for carrying out complex commands but quick for basic tasks . CISC has more complex instructions available and can therefore perform complicated tasks . Cost RISC is generally cheaper to mass produce because less circuitry is required for the smaller instruction set. CISC CPUs are generally more expensive because they require more circuitry to operate. Power RISC CPUs are designed to use less power and run without dedicated cooling systems (like fans) so that they can be used in devices like smartphones . Because CISC CPUs require more circuitry this means that they generate more heat and may require a fan . CISC CPUs therefore are commonly used in desktop computers . Clock Speed RISC CPUs run at lower clock speeds than CISC CPUs. They can perform simpler tasks more quickly than CISC, but are generally not used to carry out complex instructions . CISC CPUs run at higher clock speeds than RISC CPUs. They can perform complex tasks more quickly than RISC. Protocols Protocols POP3 ( Post Office Protocol 3 ) and IMAP (Internet Message Access Protocol ) are both protocols for receiving and storing emails from a mail server. Gateway Network Devices Gateway A gateway joins together two networks that use different base protocols . For example, a gateway could link together a LAN to a WAN . HCI Human - Computer Interaction Command-Line Interface Touch-Sensitive Interface Other types of user interface do exist, such as a command-line interface (CLI ). This type of interface is entirely text-based and requires users to interact with the system by typing commands . This is a complicated process and mistakes could easily accidentally delete data. There are many commands to learn so only experts who have been trained t o learn this interface will be able to efficiently make use of it. Another type of user interface is a touch-sensitive interface , used with smartphones and tablets . A human interacts with the device by pressing on a touchscreen , making it very intuitive and suitable for most users without training. Touch-sensitive interfaces may not work with dirty or wet fingers and it will take longer to write text compared to using a keyboard. Menu-Driven Interface A menu-driven interface displays data in a series of linked menus . Examples include cash machines (ATMs) and old iPods . This type of interface is generally user friendly and easy to use as commands do not need to be memorised. However it can be annoying to find specific data through a large number of menus without a search feature. Voice-Driven Interface A voice-driven interface can be controlled by speaking commands aloud to a listening device. Examples include Amazon's Alexa devices, Apple's Siri technology and Google Home . This interface is intuitive , can be used hands-free and helps to speed up processes . However commands may be misheard or limited in what can be performed. Cyber Attacks Cyber Attacks Dictionary Password Attack This uses a file containing every word in the dictionary and cycles through them all. This method is relatively easy to program but will only break the simplest passwords . Buffer Overflow Attack A buffer is a temporary storage location . A buffer overflow attack causes a program to try to store more data in a buffer than it can hold which can lead to adjacent memory locations being overwritten . An attacker can use the buffer overflow to insert malicious code to change data or steal confidential data . Human Weakness The biggest weakness in online security is often not the systems in place but carelessness or mistakes made by humans . Social engineering means to trick others into revealing their personal data by posing as a trusted source . For example, impersonating an IT technician via email and asking to send a username and password. Humans can accidentally compromise data by downloading malicious files or being unsafe online, like using the same password for multiple different accounts. Attackers can access unauthorised information in person by shoulder surfing and watching them as they enter sensitive data such as a PIN or password. Software Protection Software Protection The following methods of protection are considered in the design, testing and creation stages of developing software . Secure by Design This method puts security as the most important concept when creating and designing software . By focusing on security when designing software there should be less need for later updates and patches and attacks are less likely to succeed . Too Many Permissions Apps require permission to use device features (such as the camera or microphone of a smartphone) when they are downloaded. Programmers should only request permission for features that the software requires . Some malicious apps steal data or spy on users - and the worst part is that you've given permission for it to do it! Users can avoid suspicious apps by reading reviews, checking there are no unnecessary permission requests , only downloading the software you need / will use and uninstall apps if permissions change . Scripting Restrictions A script is a set of instructions executed on a website. For example, Facebook uses a JavaScript script to post a status and another to read your private messages. The Same Origin Policy (SOP) is a security precaution that prevents websites from using scripts on other sites that you have open . For example, if you are using JavaScript to post a status on Facebook then visit an infected site, that site can't also use JavaScript to access your Facebook data, because even though they both use JavaScript, they are from a different origin . Without SOP an infected website could access personal data or infect a computer with malware by maliciously using the same scripts as other websites you have used . Programmers should set scripting restrictions when creating websites. Validation with Parameters A parameter is a measure that is used when validating data , it is usually a range or limit. For example, the parameters of a length check may be whether the data is between 1 and 10 characters . Programmers must ensure validation is used on websites with suitable parameters to prevent attacks such as an SQL injection. Data Policies Data Policies Data policies are written documents that clearly define how data should be managed in an organisation. It is important that all employees stick to these policies and requirements so that data is kept safe and can be replaced if lost or corrupted. The following methods are examples of common data policies. Acceptable Use Policy (AUP) Workplaces and schools often require people to sign an acceptable use policy (AUP) before being allowed to use the network. It is a list of rules and expected behaviour that users must follow when using the computer systems. Typical rules include: Which websites are off-limits (such as social media or gambling sites), Download permissions (such as who can download and install software) Email communication (such as appropriate language). Punishments if rules of the AUP are broken. The AUP is sometimes known as a Code of Conduct . This is an example of a formal code of practice , with written rules and clear expectations . An informal code of practice would not be officially written down , such as personal habits and preferences (e.g. email layout or desk organisation). Disaster Recovery With important data often stored on a computer network, it is absolutely vital that a detailed and effective disaster recovery policy is in place in the event of data being lost due to an unexpected disaster. Disasters include natural disasters (e.g. fire, flood, lightning), hardware failure (e.g. power supply unit failing), software failure (e.g. virus damage) and malicious damage (e.g. hacking). There are three clear parts to a disaster recovery policy: Before the disaster: All of the possible risks should be analysed to spot if there are any weaknesses in preparation. Preventative measures should be taken after the analysis, such as making rooms flood-proof or storing important data at a different location . Staff training should take place to inform employees what should happen in the event of a disaster. During the disaster: The staff response is very important – employees should follow their training and ensure that data is protected and appropriate measures are put in place. Contingency plans should be implemented while the disaster is taking place, such as uploading recent data to cloud storage or securing backups in a safe room and using alternative equipment until the disaster is over. After the disaster: Recovery measures should be followed, such as using backups to repopulate computer systems. Replacement hardware needs to be purchased for equipment that is corrupted or destroyed. Software needs to be reinstalled on the new hardware. Disaster recovery policies should also be updated and improved . Cookies A cookie is a small piece of data that is stored by websites when you visit them. They allow the website to identify the user and are often used to speed up processes , such as: Automatic login (by saving account details) Save items into a basket (such as pizza delivery sites) Display adverts related to your previous search terms . Although they can be used to save time, some argue that cookies can be intrusive and store too much information. Environmental Issues Environmental Issues Tips to Reduce Waste Turn off computers , monitors and other connected devices when not in use . Adjust power options to help minimise power consumption. Devices with the Energy Star sticker use between 30% and 70% less electricity than usual. Repair older devices rather than throwing them away. Ink jet printers use up to 95% less energy than laser jets. Think twice about printing paper, don't waste ink and remember to recycle paper . Positive Environmental Impacts Communication advancements (such as video messengers) reduces pollution as people do not have to travel to speak to each other. This is especially beneficial in business - workers can talk from the office and do not need to catch a plane to speak. Smart devices can monitor usage and reduce energy waste - such as smart air conditioners and home security systems. Collaboration software (such as cloud-based technology and Google Docs) allows experts to work together and share data. The internet and research databases allows scientists to study the environment more efficiently. Documents can be viewed on a screen rather than printed out - books and newspaper articles can be read on kindles / tablets saving paper and ink . New materials and more environmentally-friendly processes have been developed thanks to increased technology and research. Object Oriented Programming Object-Oriented Programming (OOP) Java is an example of object-oriented programming (OOP) where a programmer is able to code objects that can be visually placed onto a background. Greenfoot is an IDE for Java . Superclass A class from which other 'subclasses' will inherit characteristics ; e.g. hippos, crocodiles and polar bears will inherit properties from the Animals superclass. Object A single object from a class ; e.g. one crocodile object from the Crocodile class. Class A set of objects which share the same properties ; e.g. all PolarBears will behave in a similar way. Comment Two / symbols will allow you to write a comment to explain the code . Method A series of instructions that an object will follow . The act() method will loop in Greenfoot when the play button is pressed. Programming Programming Topics Variable Scope & Lifetime The scope of a variable refers to the parts of the program where the variable can be viewed and used , e.g. a variable with global scope can be accessed anywhere in the program . The lifetime of a variable is the amount of time the variable is stored in memory and therefore can be used , e.g. local variables can only be accessed throughout the subroutine they are created in. Programming Languages: Assembly Language HTML Greenfoot Theory Topics

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

Learn about the four types of secondary storage - magnetic, optical, solid-state and cloud. Also, learn about the data storage units from bit to yottabyte. Based on the 2020 Eduqas (WJEC) GCSE specification. 1.4: Secondary Storage & Data Units Exam Board: Eduqas Specification: 2020 Secondary storage (also known as backing storage ) is non-volatile storage used to save and store data that can be accessed repeatedly. Secondary storage is not directly embedded on the motherboard (and possibly even external ) and therefore further away from the CPU so it is slower to access then primary storage . Storage Characteristics: CAPACITY : The maximum amount of data that can be stored. DURABILITY : The physical strength of the device, to withstand damage. PORTABILITY : How easy it is to carry the device around. ACCESS SPEED : How quickly data on the device can be read or edited . COST : The average price it costs to purchase a storage device. 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. 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 COST per gigabyte than solid state . X - Not DURABLE and not very PORTABLE when powered on because moving it can damage the device. X - Slow ACCESS SPEED but faster than optical storage . 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 . Also very cheap to buy in bulk. X - Optical discs have the Slowest ACCESS SPEED . Magnetic Disks are spelled with a k and Optical Discs have a c. Solid State Storage Cloud 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 . 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. When you store data in 'the cloud', using services such as Google Drive or Dropbox, your data is stored on large servers owned by the hosting company . The hosting company (such as Google) is responsible for keeping the servers running and making your data accessible on the internet . Cloud storage is very convenient as it allows people to work on a file at the same time and it can be accessed from different devices. However, if the internet connection fails , or the servers are attacked then the data could become inaccessible . Solid State Characteristics: X - High CAPACITY but more expensive COST 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 . Cloud Storage Characteristics: ✓ - Huge CAPACITY and you can upgrade your subscription if you need more storage. ✓ / X - Cloud storage is difficult to rank in terms of PORTABILITY , DURABILITY and ACCESS SPEED because it depends on your internet connection. A fast connection would mean that cloud storage is very portable (can be accessed on a smartphone or tablet) but a poor connection would make access difficult . ✓ - Cloud storage is typically free for a certain amount of storage. Users can then buy a subscription to cover their needs - Dropbox allows 2 GB for free or 2 TB for £9.99 a month. Data Storage Units 0 / 1 All data in a computer system is made up of bits . A single bit is a 0 or a 1 . 4 bits (such as 0101 or 1101) is called a nibble . 1,024 bytes is called a kilobyte . A kilobyte can store a short email . A 8 bits is called a byte . A byte can store a single character . 1,024 kilobytes is called a megabyte . A megabyte can store about a minute of music . 1,024 megabytes is called a gigabyte . A gigabyte can store about 500 photos . 1,024 terabytes is called a petabyte . A petabyte can store about 1.5 million CDs . 1,024 gigabytes is called a terabyte . A terabyte can store about 500 hours of films . More data storage units: 1,024 petabytes is called a exabyte . 1,024 exabytes is called a zettabyte . 1,024 zettabytes is called a yottabyte . Q uesto's Q uestions 1.4 - Secondary Storage: 1. Rank magnetic , optical and solid-state storage in terms of capacity , durability , portability , speed and cost . For example, magnetic has the highest capacity , then solid-state, then optical. This could be completed in a table . [15 ] 2. Justify which secondary storage should be used in each scenario and why it is the most appropriate: a. Sending videos and pictures to family in Australia through the post . [ 2 ] b. Storing a presentation to take into school . [ 2 ] c. Storing project files with other members of a group to work on together . [ 2 ] d. Backing up an old computer with thousands of files to a storage device. [ 2 ] 3. Put the following data storage units in order from smallest to largest : a . kilobyte - gigabyte - byte - megabyte - nibble - bit [3 ] b. gigabyte - petabyte - kilobyte - exabyte - terabyte - megabyte [ 3 ] 1.3 - Primary Storage 1.5 - Performance Theory Topics

Learn about application platforms such as augmented reality (AR), virtual reality (VR) and mixed reality (MR), websites and computer games. 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 1.1 - Application Platforms Watch on YouTube : Reality Platforms Websites Computer Games There are three types of application platforms you need to know, starting with devices based around merging technology and reality -augmented reality (AR ), virtual reality (VR ) and mixed reality (MR ). You also need to understand how websites and computer games are used as application platforms . You need to know the uses of these application platforms as well as their advantages and disadvantages . What You Need to Know Augmented Reality / Virtual Reality / Mixed Reality Augmented Reality (AR ) is technology that overlays digital images or information onto the real world . Virtual Reality (VR ) uses a computer-generated 3D environment that fully immerses the user , usually with a headset . Mixed Reality (MR ) is a blend of AR and VR where digital objects interact with the real world in real time . AR , VR and MR devices have a wide range of uses , the main three being educational , instructional and for research . Websites Websites can be used as platforms to deliver applications directly through a web browser , removing the need for users to install software on their device . This allows applications to be accessed easily across different devices and operating systems using an internet connection . There are four categories of websites to know: E-Commerce Instructional Educational Social Media Computer Games Computer (video ) games can be used as application platforms by combining software functionality with interactive gameplay and immersive environments . Games can increase user engagement and allow complex ideas , simulations or training activities to be delivered in a more intuitive and motivating way. Games are highly engaging , increasing user motivation and time spent using the application but game development is often complex , time-consuming and expensive , requiring specialist skills in a range of job roles . Q uesto's Q uestions 1.1 - Application Platforms: 1. Give the key features and uses for each reality-based device - AR , VR and MR . [4 marks each ] 2. Give three advantages and disadvantages of using a website as an application platform . [6 ] 3. A school is considering making a computer game application to encourage students to learn about rainforests . Consider two advantages and disadvantages of using computer games as an application platform in this scenario . [4 ] There are over 1 billion websites on the internet , but fewer than 20% are actively maintained , meaning most websites are abandoned , inactive or placeholder pages . D id Y ou K now? Topic List 1.2 - Devices

Learn how to input numbers in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 2B - Inputting Numbers Inputting Whole Numbers in Python To enter whole numbers then you must use the int command. int stands for integer (a whole number ) and is typed before input – don’t forget the double brackets at the end . age = int ( input ( "How old are you? " )) print ( "Have you really lived for " , age , "years?" ) = How old are you? 99 Have you really lived for 99 years? Inputting Numbers Task 1 ( Zoo) Type an input line (with int ) to ask the user how many times they’ve been to the zoo . Print a reply that uses the zoo variable (their answer). Example solution: How many times have you been to the zoo? 3 You've been to the zoo 3 times? I love animals! Inputting Decimal Numbers in Python Using float instead of int allows a decimal number to be entered instead. Again, don’t forget the double brackets at the end . miles = float ( input ( "How far have you walked today? " )) print ( "You really walked for " , miles , "miles? Wow!" ) = How far have you walked today? 5.6 You really walked for 5.6 miles? Wow! Inputting Numbers Task 2 ( Height ) Type an input line (with float ) to ask the user their height in metres. Print a reply that uses the height variable (their answer). Example solution: What is your height in metres? 1.82 You are 1.82 metres tall? Wow! ⬅ 2a - Inputting Text Sect ion 2 Practice Tasks ➡

Test your ability to create a more complex program in Python based on a given scenario. Perfect for students learning GCSE Computer Science in UK schools. Extended Task 6 'Guess the Word' Game Create a Python program similar to the hit New York Times puzzle game Wordle . Allow the user to make guesses to match the randomly chosen hidden word , stopping when they get it correct. You can download a list of 5-letter words on this page. You will need to read in each line of the list and randomly select one - don’t forget to import the random library . Check if each letter of the user’s inputted word is in the randomly selected word . If you are using an IDE like Replit you can use the colorama library and the Fore command to turn the text: Green if the letter is in the correct position . Red if the letter is not in the selected word . Yellow if the letter is in the selected word but not in the correct position . Add your own flair and additional features to your program as an extension, including limiting the number of guesses and recording how many attempts it took to get the correct answer. Download a file of 534 5-letter words: For this task, you will need to create a document and include the following sections (with screenshots where appropriate): An introduction to explain the Purpose of your program . A List of Requirements for a successful program. Screenshots of your code (with comments in your code to show understanding). Testing – Create a plan to show how you will test your program and then explanations of any errors that you found and how they were fixed . An Evaluation of what worked, what didn’t, and how you met each of your requirements from your original list. Also, discuss further improvements that you could have made to improve your program. Reminders for this task: You will need a while loop to repeatedly allows the user to enter words until they match the correct word. Section 10 will help you to open, write and r ead from files . Download the file of 5-letter words from the link above. You will need to randomly select a word from the file. The choice command will help. Selection will be necessary to check if each letter in the inputted word matches the letter in the same position in the correct word. String handling is needed to select specific letters in a string. You will need to use .rstrip() on the selected line (word) that you have randomly chosen from the file. This removes any hidden characters that may interfere with checking if it is equal to the inputted word. There are multiple ways to approach this program, and your solution might look different from the example. Break the problem down and focus on one part at a time. Example solution: The word the user enters should be checked , letter by letter , against the letters in the same position in the randomly chosen correct word . Remember that the first letter in a word has the position 0 , not 1. Below is an example of some incomplete code you may wish to use in your solution. ⬅ Extended Task 5 (Colour Collection) Extended Task 7 (Number Game) ➡

Learn how to create print statements in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. top Python 1a - Printing Printing in Python To output a message onto the screen, use the print command. Then place your message within brackets and speech marks . For example: print ( "Welcome to Python!" ) When you run the program, the text will print to the Python console: Welcome to Python! Printing Task 1 (Full Name & To Your Left) On the first line, print your first name and surname. On the next line, write another print statement to print t he name of the person (or thing) to your left. Example solution: Elsie Parker pencil case Printing over Several Lines One way of writing across multiple lines is to write several print commands like this: print ( "Welcome to...." ) print ( "Computer Science " ) print ( "Newbies!!! " ) = Welcome to .... Computer Science Newbies!!! However, when we program, we always want to make our code the most efficient it can be by using as few lines as possible . Therefore you can write \n within a printed statement to move it to the next line. Make sure you use \ and not / otherwise it will print the slash and not make a new line! print ( "Welcome to....\n Computer Science\n Newbies!!! " ) = Welcome to .... Computer Science Newbies!!! Both pieces of code display the same thing, but the second one is more efficient because it only uses one line. Printing Task 2 (Name, Colour, Movie) Use \n to write your name, favourite colour and favourite movie in only one line of code. Example solution: Matthew yellow Interstellar ⬅ Setting Up Python 1b - Comments ➡

Learn about key mnemonics used in assembly language and how very simple programs can be created. Assembly Language Assembly language is a low-level programming language - it is closer to machine code (binary) than high-level programming languages like Python. Assembly language uses mnemonics (abbreviations of commands) to signify instructions; for example, input is written as INP and output is written as OUT . Little Man Computer is a representation of assembly language . This simulator will help you understand assembly language and allow you to check if your instructions are correct. Assembly Language Mnemonics INP (Input) INP is used to input a number . The number is temporarily stored in the accumulator . OUT (Output) OUT is used to output the number currently stored in the accumulator . STA (Store) STA stores the value that is currently in the accumulator . It can be used to assign a value to a variable. ADD (Addition) ADD is used to add a number to the value currently stored in the accumulator. SUB (Subtraction) SUB takes away a number from the value currently stored in the accumulator. LDA (Load) LDA is used to load the value of a stored variable back into the accumulator . BRZ (Branch if Zero) BRZ is used to loop only if the value in the accumulator is currently 0 . BRP (Branch if Positive) BRP is used to loop only if the value in the accumulator is currently positive (including 0). BRA (Branch Always) BRA is used to loop continuously . HLT (Halt) HLT will stop running the program . Every program MUST have a HLT command. DAT (Data Definition) DAT must be used to define a variable name (and / or set it with a starting value). Data definitions must be written at the end of the instructions . Peter Higginson's Little Man Computer simulation Examples of Simple Assembly Language Programs #1 - Input & Output Program Purpose: Input a number, store the number as a variable called Number1 and output the number. 1. Lets the user input a number 3. Outputs the value in the accumulator - which will be the number that was just inputted. 5. Defines a variable called 'Number1'. This has to be at the end of the program and you must write the variable name first, not the command first. INP STA Number1 OUT HLT Number1 DAT 2. Stores the number in a variable named 'Number1' - there must be no spaces in a variable name. 4. Halts (stops) the program. Type these instructions line by line into the Little Man Computer simulator to see how it works. #2 - Addition Program Purpose: Input and store two numbers. Add them together. Output the total. 1. Lets the user input a number 3. Lets the user input another number 5. Adds number1 to the value in the accumulator (which is currently number2 as you just inputted it). 7. Halts the program. Type these instructions line by line into the Little Man Computer simulator to see how it works. Then change the program to subtract the number instead. INP STA Number1 INP STA Number2 ADD Number1 OUT HLT Number1 DAT Number2 DAT 2. Stores the inputted number in a variable named 'Number1'. 4. Stores the inputted number in a variable named 'Number2'. 6. Outputs the value in the accumulator (which is now number1 added to number2. 8. & 9. The two variables Number1 and Number2 are defined on separate lines. #3 - Load in Order Program Purpose: Input and store three numbers. Load and output them in the order that they were entered. 1. - 6. Lets the user input three numbers and immediately stores each one as they are entered. 8. Now that Number1 has been loaded into the accumulator, this value is outputted. 13. Halts the program. Type these instructions line by line into the Little Man Computer simulator to see how it works. Let the user input a fourth number and output this fourth number last . INP STA Number1 INP STA Number2 INP STA Number3 LDA Number1 OUT LDA Number2 OUT LDA Number3 OUT HLT Number1 DAT Number2 DAT Number3 DAT 14. - 16. The three variables Number1, Number2 & Number3 are defined on separate lines. 9. - 12. Number2 is loaded and output then Number3 is loaded and output 7. Once all three numbers have been inputted and stored, the first number is loaded back into the accumulator. #4 - Branching Program Purpose: Input and store two numbers. Output the largest number. (Branching required). 1. - 4. Lets the user input two numbers and immediately stores each one as they are entered. 7. BRP is 'Branch is Positive'. If the result of Number1 - Number2 is positive then the program will jump to line 11. You can write any value instead of 'loop', such as 'jump' or 'break'. If the result is not positive it will continue to the next line. 11. - 13. The program will jump to line 11 if the result of Number1 - Number2 is positive. This means that Number1 is larger than Number2 so Number1 is loaded and output then the program is halted. INP STA Number1 INP STA Number2 LDA Number1 SUB Number2 BRP loop LDA Number2 OUT HLT loop LDA Number1 OUT HLT Number1 DAT Number2 DAT 5. & 6. Loads Number1 and subtracts Number2 from it. 8. - 10. The program will continue to line 8 if the result of Number1 - Number2 is not positive. Because the result is a negative number, this tells us that Number2 is larger than Number1. So we load Number2, output it because it is bigger, then halt the program. 14. - 15. The variables Number1 & Number2 are defined on separate lines. Type these instructions line by line into the Little Man Computer simulator to see how it works. Change the program so that the smallest number is output .

Learn about the role of different server types including file, application, print, email, mail servers and the hypervisor. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 3.1 - Server Types Exam Board: OCR Specification: 2016 - Unit 1 What is a server? A server is a powerful dedicated system on a network . It requires increased memory , storage and processing power than traditional computer systems to fulfill its role across the network. Servers need to be scalable - this means they must be adaptable and able to efficiently manage the needs of connected systems if more are added or some are removed . Servers have different roles so a company may use multiple , separate server types within their organisation, each with a specific purpose . Having separate servers is costly but beneficial as if one loses connection , others may still be usable . Also a server will be more efficient if it is only managing one resource (e.g. printers) at a time . File Server A file server centrally stores and manages files so that other systems on the network can access them. The server provides access security , ensuring that only users of the appropriate access level can access files. File servers can be used to automatically backup files , as per the organisation's disaster recovery policy. Using a file server frees up physical storage space within a business and can provide printing services too. Printer Server These servers control any printers on a network and manage printing requests by sending the document to an appropriate printer. Print servers use spooling to queue print jobs so that they are printed when the printer is ready. If a fault occurs with a certain printer, work can be automatically diverted to another available printer. Application Server These servers allow users to access shared applications on a network. All users will be able to access common applications like email software or word processing, but the server will also restrict certain applications to those with invalid access levels (such as hiding financial databases from employees outside of the finance department). Application updates can be simply deployed to the application server only , avoiding individual updates for each system and saving a lot of time . Installers can be hosted on an application server, allowing the software to be easily installed on other connected machines . Database Server These servers manage database software that users on the network can access and use to manipulate data . Data held on the server will be stored in a database accessible from multiple connected computers . The data can be modified using query languages such as SQL. Storing data on a database server, rather than individual computers, is more reliable . A database server for a business also allows for scaling - for example, the database can be increased in size if the customer base grows. Web Server A web server manages HTTP requests from connected devices to display web pages on web browsers . A request (e.g. csnewbs.com) is sent to the web server. The server contains a list of known URLs and their matching IP addresses . The server contacts the server where the web page is held and delivers the web page to the client . Mail Server These servers send and receive emails using email protocols (SMTP & POP) allowing email communication between other mail servers on other networks. The server makes sure emails are delivered to the correct user on the network. Email servers can store company address books making internal communication easier for organisations. The server may have anti-spam functions to reduce junk mail. Hypervisor A hypervisor allows a host machine to operate virtual machines as guest systems. The virtual machines share the resources of the host , including its memory, processing power and storage space. This type of technology is called virtualisation . The guest machines are isolated so if one failed, the other guests and the hosts are not affected - demonstrating good security . The hypervisor optimises the hardware of the host server to allow the virtual machines to run as efficiently as possible. Q uesto's Q uestions 3.1 - Server Types: 1a. What is a server ? Why does it need to be scalable ? [2 ] 1b. Give two reasons why a company may use multiple , separate servers . [2 ] 1c. State the 7 types of server . [1 each ] 2. A medium-sized animation company working on a movie are considering buying a server. Describe each type of server and the different roles they have. a. File Server b. Printer Server c. Application Server d. Database Server e. Web Server f. Mail Server g. Hypervisor [4 each ] 3. What type of technology does a hypervisor use to control multiple virtual machines? [1 ] 2.7 - Protocols Topic List 3.2 - Virtualisation

A glossary of important code to be used in Greenfoot, such as random movement, using a counter removing objects and sound. Aimed at the Eduqas / WJEC GCSE specification. Greenfoot Code Glossary Greenfoot Home This code will work for Version 2.4.2 which is used in Component 2 of the 2016 WJEC/Edquas specification . Key Down 270 if (Greenfoot.isKeyDown("right" )) { setRotation(0); move(1); } 180 90 0 Bounce At Edge if (isAtEdge()) { turn(180); } move(1); if (Greenfoot.getRandomNumber(10)<1) { turn(Greenfoot.getRandomNumber(90) - 45); } Random Remove Object if (isTouching(Apple.class )) { removeTouching(Apple.class ); } Play Sound Greenfoot.playSound("pop.wav" ); Stop Greenfoot.stop(); Counter - (Write this code when an object is removed) Counter counter = (Counter) getWorld().getObjects(Counter.class ).get(0); counter.add(1); 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.