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Based on the 2015 OCR Computer Science A-Level specification. Exam Board: OCR 1.3a: Input & Output Devices Specification: A-Level 2015 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 This page is still being updated. Graphical Processing Unit What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Q uesto's Q uestions 1.3a - Input & Output Devices: 1. What is cache memory ? [ 2 ] 1.2 Processors Theory Topics 1.3b - Memory & Storage

Learn about input and output devices used with computer systems. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 1.1 - Computer Hardware Exam Board: OCR Specification: 2016 - Unit 1 Input Devices An input device allows data, such as text, images, video or sound, to be entered into a computer system. Common input devices: Mouse Keyboard Scanner Controller Microphone Webcam Chip Reader OCR / OMR Scanner Barcode Scanner Graphics Tablet Sensors (e.g. light or temperature) Touch Screen Remote Control Biometric Scanner (e.g. fingerprint or iris) Concept Keyboard Output Devices There are many outputs created by a computer system, including printed documents, on-screen data and sound. Common output devices: Monitor Printer (e.g. inkjet or laser) Plotter Speakers Projector Alarm Light Headphones Touch Screen Braille Terminal Communication devices can be found in 1.5 . Biometric Devices A biometric device uses a human characteristic as part of its security mechanism, such as a fingerprint , iris (eye), face o r voice . Organisations using biometrics must instruct each employee to first input their information to a database , by scanning their fingerprint for example. Whenever the scanner scans a finger it searches in its database to see if the fingerprint matches one that it already holds . Only authorised employees will have already scanned their fingerprints so if there is no match then access is not allowed . Advantages of biometric devices: Security is improved as biometrics can't be shared like passwords can. Even if a password is exposed the system can't be accessed without having the biometric too. Biometric scanners verify that a user is who they claim to be. Using a biometric device (e.g. fingerprint scanner) might be quicker and easier than entering a username and password. Disadvantages of biometric devices: Can be expensive to install and all users must take the time to initially set up by entering their biometric into the database so they will be recognised by the system. Unreliable in that it can be affected by the environment (e.g. dirty fingers can't be used with a fingerprint scanner or voice recognition may not work in a loud environment). Disabled users might not be able to provide the biometric required. Privacy concerns - users might not want their personal characteristics stored on a computer system. Q uesto's Q uestions 1.1 - Computer Hardware: 1. Make a list of 5 input devices and 5 output devices . Challenge yourself to look up and include devices from this page you may not be familiar with. [10 ] 2a. State 3 human features that may be recorded by a biometric device . [3 ] 2b. Describe how a biometric device works . [3 ] 2c. A school is considering installing biometric devices to allow only sixth form students to enter certain parts of the school. Describe 3 advantages and 3 disadvantages to the school of using biometrics in this way. [10 ] Topic List 1.2 - Computer Components

Learn about the advantages and disadvantages of networks, the five types of network - LAN, WAN, PAN, MAN and VPN - and differences between wired and wireless networks. Based on the 2020 Eduqas (WJEC) GCSE specification. 3.1: Network Characteristics Exam Board: Eduqas / WJEC Specification: 2020 + What is a network? A network is more than one computer system connected together allowing for communication and sharing of resources . There are many benefits but also some drawbacks to using a network compared to having an unconnected ('standalone' ) computer: Advantages of Networks Easily share files , software and hardware between computers. Disadvantages of Networks There is an initial cost because network devices like routers are required . Larger companies will need to buy and maintain a server . Log in from any connected computer and access your data and files. A network manager / administrator might need to be employed to maintain the network . An administrator can monitor network activity and control security settings. Data from computers on the network can be automatically backed up on central storage. Security breaches are more likely and malware , such as worms, can spread quickly across the network. If the web server fails , all connected computers won't be able to access files or log on . Network Types Networks can be split into different types , usually categorised by their geographical distance apart and the area that they serve. Local Area Network A local area network (LAN ) has computer systems situated geographically close together , usually within the same building or small site , like a school or office . Wide Area Network A wide area network (WAN ) has computer systems situated geographically distant to each other, possibly across a country or even across the world . The internet is an example of a WAN that spans the globe. Personal Area Network A PAN is a personal network for an individual , such as a photographer connecting a smartphone, desktop computer and printer together. Metropolitan Area Network A MAN is larger than a LAN but smaller than a WAN and typically covers a relatively large area like a university campus, town or city . Virtual Private Network A VPN allows for a secure and encrypted connection to a public network like the internet. It is often used to protect an individual's privacy by concealing their real location. Wired & Wireless Networks Wired Connections Wireless Connections Wireless connections, such as WiFi or Bluetooth , use no cables but require a wireless network interface card (WNIC ). Wireless connections generally have a slower speed and can be affected by the computer's distance from the wireless router as well as obstacles like walls or bad weather. Wired connections use physical cables , such as copper or fibre optic wires , and require a network interface card (NIC ) to connect to a network. These wired connections use a wired connection protocol - most commonly Ethernet . Restricted Movement Faster More Secure NIC Required Freedom of Movement Slower Less Secure WNIC Required Q uesto's Q uestions 3.1 - Network Characteristics: 1. A retirement home for the elderly is considering installing a LAN , give 3 benefits and 3 drawbacks they might find of using a network . [6 ] 2a. Describe the difference between a LAN and WAN . [2 ] 2b. Give an example of how a LAN and a WAN could each be used . [ 2 ] 3 . Explain the differences between a PAN , MAN and VPN . [ 3 ] 4. For each of the scenarios below, state which network type would be most suitable : a. The IT rooms of a secondary school . [ 1 ] b. A study in a house with a desktop and printer. [ 1 ] c. Using online banking when abroad on a holiday to stay secure . [ 1 ] d. A large technology company with offices across Europe . [ 1 ] e. Council offices with several locations across Manchester . [ 1 ] 5. Briefly compare wired and wireless networks . [ 8 ] 2.2 - Boolean Algebra 3.2 - Data Packets & Switching Theory Topics

Learn about ethical, legal, cultural, privacy and environmental impacts of digital technology. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 6.1a: Impacts of Technology Exam Board: OCR Specification: J277 What are the issues created by technology? As the use of computers and technological devices continues to rise every year, this increase brings with it a range of different types of issues . Categories of issues described on this page include: Cultural issues Environmental issues Ethical issues Legal & Privacy issues Cultural Issues Culture relates to society and how different parts of the world vary in terms of computer and internet usage . The Digital Divide This term relates to the gap between those people who have access to modern digital technology (such as computers and the internet) and those who have limited access . 'Limited access' could be devices at home or shared devices or having lower-performance (cheaper) computers and low-speed internet connections. The digital divide can be seen in different ways , such as: People in cities vs. People in rural areas . Younger people vs. Elderly people. Developed countries vs. Developing countries. The digital divide is an important ethical issue because digital technologies have led to numerous international benefits including boosted growth , improved product delivery , enhanced communication and increased opportunities . However, this impact is uneven and these positive impacts are mostly occurring in technologically-advanced regions such as North America , Western Europe and Japan . Regions like some nations in Africa and Central Asia have limited digital infrastructure and government instability , leading to poor internet speeds , high costs and limited resources . Discussion Points: What do you think can be done to bridge the digital divide? Whose job is it to bridge the gap? Who will pay for the technology? Changes to Work The internet , the development of new technologies such as cloud storage and increased video communication have transformed the way that many businesses operate across the world. Staff may be able to work from home or access documents collaboratively outside of the traditional workplace, such as cafes or on public transport. Some jobs have moved abroad to save costs, such as help centres for online issues. Tasks can be outsourced to freelancers in other countries where people are content to be paid less for their time and services. For example, some companies will hire temporary web developers from countries such as India to work for them for a lower salary than local workers. Another change to work that technology has brought is the loss of jobs , especially low-skilled jobs such as factory workers that have seen their roles replaced by technology and automation . However, technology has also created millions of new jobs , including installing and maintaining the machines that replace other roles. Environmental Issues Environmental issues concern the natural world and the negative effects of producing , using and discarding computer systems and devices. Energy and Material Consumption In the past 30 years, the number of technological devices has increased astronomically and thousands of new devices are manufactured each day . These devices need to be assembled using a range of materials , including plastics , metals and some rarer elements and need a considerable amount of electrical power to run. Certain systems like web servers and data centres must be powered on all day , every day, which uses a large amount of energy . Pollution and Waste Generating the electricity to power computers creates pollution - an average PC could require up to 50% more energy per year than a fridge. Computers are difficult to recycle and discarded components can lead to land, water and air pollution due to harmful materials , such as lead and mercury , leaking into the environment. Smartphone trends are also negative for the environment as new devices are released yearly , with minor upgrades that people buy to appear fashionable and up-to-date. To lessen the environmental impact, people should reuse and recycle their devices. Ethical Issues Ethics relates to what is considered right or wrong . Often this is subjective - people may have differing opinions on the issue. Drones Uses of drones: Filming and photography for television, movies and special events. Monitoring pollution levels in the atmosphere. Tracking and monitoring wildlife , such as rhino populations in Africa. Disaster zone response , such as searching for survivors following an earthquake. Delivery companies are developing drones to quickly deliver goods across cities. Drones are used by the military to target sites in other countries, such as American soldiers deploying surveillance drones in Syria. Discussion Points: Should you need a licence to buy and fly a drone? Should drones be used to monitor the public? Like flying CCTV? Should drones be used to deliver items? Like Amazon packages? If a drone hits a plane and it crashes, what should the punishment be? A drone is an unmanned aerial vehicle (UAV ) that is remotely operated and can be used for a wide range of purposes. Self-Driving Cars Self-driving cars (also known as autonomous vehicles ) are currently in the development and testing stage with companies like Tesla and Amazon. Benefits of self-driving cars include: In theory, driving will be safer because cars are less likely to make mistakes that humans do and they can’t become distracted or tired . Self-driving cars should be more fuel-efficient because they take the most direct route to destinations and do not get lost. ‘Drivers’ in the car can perform other tasks instead of driving, such as work or planning. Autonomous vehicles could include trucks and vans to automate the delivery and freight industries . Trucks could drive overnight to deliver goods whereas currently, human drivers must take breaks every few hours. Drawbacks of self-driving cars include: Cars could still crash as code and software processes may fail. The technology is still in development and will be very expensive for the first few years when self-driving cars are available to purchase. Jobs may be lost such as delivery and truck drivers whose vehicles are equipped with self-driving technology. Other industries like motorway services and hotels may also be affected. Discussion Points: Would you trust a car to drive itself? Who is to blame if a self-driving car crashes? The car maker? The people in the car? The software writers? What should happen to the people whose jobs are taken by self-driving vehicles? Artificial Intelligence Artificial Intelligence (AI ) is the act of computers replacing humans to analyse data and make decisions . In recent years AI has become more common in the home and on devices like smartphones; assistants such as Siri and Alexa are prime examples of modern home AI. AI Chatbots like ChatGPT have become more popular in recent years but have lead to issues such as plagiarism , misinformation and breaking copyright laws . The weather today is cloudy. Benefits of AI include: Processes are sped up as computers can analyse large amounts of data much quicker than a human. AI can be used when a human is unavailable , such as using a symptom checker on the internet for a minor illness rather than booking and waiting for a doctor. Repetitive or time-consuming tasks can instead be completed by a computer , such as searching and sorting scientific data or generating ideas , images or audio from a prompt . Drawbacks of AI include: AI can store and process a lot of personal data , especially personal assistants like Alexa which are always listening for ‘wake words’. This data can be viewed by the company that develops it and could be hacked by attackers. AI is programmed by humans and mistakes in code could have disastrous consequences if the AI is used to make important decisions , such as military deployment. AI GPT tools like ChatGPT can give incorrect results , may use copyrighted material in their response and students may use it to submit work that is not their own . Discussion Points: If a robot harms a human who is to blame? The robot? The programmer? The manufacturer? Us? Would you trust a walking, talking robot assistant in your home? Should ChatGPT be banned in schools or can it be helpful? Should AI make decisions for us? Legal & Privacy Issues Legal and privacy issues regard laws that have been introduced by the UK government to protect data, systems and networks from unauthorised access . See 11.2 for explanations about important computing legislation in the UK. Loss of Privacy & Hacking There has been a lot of criticism in the last few years about how internet companies and governments are using personal data to invade privacy and track civilians . Facebook was involved in a scandal with using personal data for reasons that were not the original intention. In reverse, WhatsApp and Apple have been criticised for encrypting messages sent by terrorists that police have been unable to track and read. Every week a new company seems to announce that its data has been hacked . Attackers are constantly using botnets and infected systems to crack poorly secured databases and attempting to phish individuals for usernames and passwords. In the past few years, major hacking breaches include Sony, Yahoo and TalkTalk. Discussion Points: Should the UK government be able to see the websites you have visited in the last year? What should happen if a major company is hacked and bank details are stolen? Should they be fined? Pay customers? Prison? Should WhatsApp allow authorities to access encrypted messages? What if they know a terrorist is using it to communicate? Should the UK debate privacy laws before they go into place? Online Crime Unlawfully obtaining personal information and using it for identity theft or fraud . Harassment and threatening others on social media or private messages; blackmail . Cyber attacks are more common - see 3.8 for information about DOS attacks , IP spoofing , SQL injection and more. Sharing copyrighted material such as television programmes, music and video games. Distributing prohibited material such as drugs or weapons on the dark web. See 6.1b for explanations about different laws that have been created to tackle online crime . The increased popularity of the internet and the rising number of users has led to a wave of online crime , taking many different forms, including: Q uesto's Q uestions 6.1a - Impacts of Technology: Cultural Impacts 1a. What is the digital divide ? [ 2 ] 1b. Describe 2 examples of how the digital divide can be seen . [ 2 ] 2. Describe in detail 3 ways that technology has changed the way people work . [9 ] Environmental Impacts 1. Describe the different ways that the increasing use of technology negatively impacts the environment . [ 5 ] Ethical Impacts 1a. What is a drone ? [1 ] 1b. Make a list of all of the positive impacts and the negative impacts of using drones . You should have at least 3 on each side. [ 6 ] 2. Describe 2 benefits of using self-driving cars and 2 negative consequences . [4 ] 3. Describe how artificial intelligence can be used for good . [ 4 ] Legal & Privacy Impacts 1. A hack on a bank has occurred. Describe what you think the impacts would be on the following groups of people: a. The customers . b. The bank managers . c. The general public . [ 6 ] 2. Describe 4 different types of online crime . [ 8 ] 5.2 - Utility Software Theory Topics 6.1b - Legislation

Learn about how to perform binary addition and binary shifts. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 2.4b: Binary Addition & Shifts Exam Board: OCR Specification: J277 Watch on YouTube : Binary Addition Overflow Errors Binary Shifts Issues with Shifts Binary Addition Binary addition is a method of adding binary values without having to convert them into denary. How to add binary numbers: What is an overflow error? An overflow error occurs when a binary value is too large to be stored in the bits available . With a byte (8 bits ) the largest number that can be held is 255 . Therefore any sum of two binary numbers that is greater than 255 will result in an overflow error as it is too large to be held in 8 bits . What is binary shift? Binary shift is used to multiply and divide binary numbers . The effect of shifting left is to multiply a binary number. The effect is doubled by each place that is shifted . x The effect of shifting right is to divide a binary number. ÷ Shifting by 1 has an effect of 2 . Shifting by 2 has an effect of 4 . Shifting by 3 has an effect of 8 . For example, shifting left by 2 places has an effect of multiplying by 4 . Another example: Shifting right by 3 places has an effect of diving by 8 . How to shift a binary number: Binary Shifts Watch on YouTube Watch on YouTube Q uesto's Q uestions Binary Addition: 1. Explain what an overflow error is. [ 2 ] 2. Add together the following binary values. If an overflow error occurs you must state one has occurred. a. 010110012 and 010001012 [2 ] b. 110110112 and 010111012 [2 ] c. 001101102 and 011010112 [2 ] d. 110110112 and 010101112 [2 ] e. 011011012 and 110101102 [2 ] Binary Shifts: 1a. Draw a diagram to show the effect of multiplying and dividing a binary number . [2 ] 1b. Draw a diagram or table to show the effect a shift has for each place from 1 to 4 . For example, a shift of 1 place has an effect of 2. [4 ] 2. State the effect of the following shifts: a. Shift right by 2 places. b. Shift left by 1 place. c. Shift left 3 places. d. Shift right by 4 places. [ 1 each ] 3. Shift the following binary numbers and state the effect of the shift: a. 10101011 : Shift left by 2 places. b. 11101100 : Shift right by 3 places. c. 00001011 : Shift right by 2 places. d. 01101110 : Shift left by 1 place. [ 2 each ] 2.4a - Number Systems Theory Topics 2.4c - Character Storage

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 5 Collection of Colours A new paint company , 'Sparkle and Shine Paint Schemes ' needs a program that can manage the different colours they sell to customers. They currently have a file with many different colours and want a program made with features to add, remove and list the different colours . 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 to create a selection of options for the user to choose from. Subroutines and a while true loop may help. Section 10 will help you to open, write and read from files . Section 10c shows how to remove lines from a file. 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: Use a menu to select the different options using a command word. Download the colours file: Selecting Total will list the number of colours in the file. This should change whenever a new colour is added or one is removed . Selecting Add will allow the user to enter the name of a new colour to be added to the file . Selecting Letter will allow the user to enter a letter . All colours beginning with that letter should be displayed . Selecting Remove will allow the user to enter a colour to be removed from the file . Selecting Random will display a random colour from the file. Selecting End will stop the program. ⬅ Extended Task 4 (Vet Surgery) Extended Task 6 (Word Game) ➡

Learn how to start a new Greenfoot program and set up the world and actors ready for the next steps in creating a game. Part 1 of the Greenfoot Tutorial for the Eduqas/WJEC GCSE 2016 specification. 1. Setup & Populating the World Greenfoot Tutorial 1. Open Greenfoot This tutorial uses Version 2.4.2 which is the version students are given to use in the WJEC/Eduqas Component 2 exam . Click here for more information and how to download 2.4.2 . If you are using a more recent version the code should still work but the look of the program in the screenshots may be different. In the Component 2 exam of the 2016 WJEC/Eduqas specification you would skip ahead to the New Object Placements stage further down this page as the classes should be set up for you. Watch on YouTube: 2. New Scenario For a new project, click ' Scenario ' and then ' New '. If you are using a more recent version of Greenfoot select ' New Java Scenario '. Save this new project in a suitable location such as a folder named 'Greenfoot' . You may wish to save this project as ' SimpleGame ' or ' ExampleGame '. 3. Setup the MyWorld class The first thing to do is to create a subclass of World called MyWorld which becomes our background object. Right-click on the World class and select 'New subclass... ' Set the New class name to MyWorld . Choose any image from the 'backgrounds ' image category. I have chosen the 'cell.jpg ' image. Click the Compile button in the bottom right of the Greenfoot window to save the program . 4. Create the Main Character class Now to create a new class for the main character. Right-click on the Actor class and select 'New subclass... ' Give the new object an appropriate name and choose a relevant image . I have named my class 'Sheep ' and selected the sheep.png image. 5. Right-click on Actor and create two more classes: Collectable objects to pick up (e.g. my orange) An enemy character to avoid (e.g. my elephant) Don't forget to compile the program. Watch on YouTube: After creating your classes you must move them over to the game world. This is known as populating the world . 1. New Object Placements Right-click on your main character object and select the top option e.g. 'new Sheep()'. Drag your mouse to the world and click to drop it. Complete the following actions: Place 1 main character object. Place 5 collectible objects. Place 2 enemy objects. 2. Save the World Once you have populated your world with objects then right-click anywhere on the background and select 'Save the World '. This saves the positions of each object so that it won't reset every time you start a new game. You can close the MyWorld code that automatically opens when you save the world, we never add any code to this window. Part 2 - Movement (Arrow Keys) >

Learn how to create simple programs in Python. Try practice tasks and learn through text and images. Perfect for students learning GCSE Computer Science in UK schools. Setting up Python Downloading Python If you are using Python in Computer Science lessons, then your school should already have it downloaded and installed on the school computers. It is a good idea to download it on a home computer too so you can practice outside of lessons. Python is free and can be downloaded from the official website. You should download the most up-to-date version of Python 3. Save the file and then run it to start installing. Official Download Page Using Python When you run the Python application, it will open the shell. This window will display the outputs of any program you have created. Do not type into the shell . Click on the File tab then New File to open the editor. Python Shell - This displays the outputs of your program. Do not write directly into the shell . Python Editor - All code is written into the editor. When you want to test a program press the F5 key (or click the Run tab then Run Module ). The first time you test a program, it will prompt you to save the file. Make sure you save it somewhere you will remember - it is a good idea to create a folder named 'Python' where you can keep all your practice programs. The next page looks at actually creating a program but above shows how code has been typed into the editor and then displayed in the shell. You never need to save the shell window. Also, the editor saves automatically every time you run the program. Opening a Saved Program When you want to re-open and edit a file you have created previously double-clicking on it won't work . Right-click on the file and select Edit with IDLE : https://trinket.io/python/76b41b35c5 1 a - Printing ➡

Learn about the two types of language levels, high level and low level, including explanations and examples. Based on the 2020 Eduqas (WJEC) GCSE specification. 7.1: Language Levels Exam Board: Eduqas / WJEC Specification: 2020 + There are two types of programming languages used within computer systems: High-Level Languages Why do programmers use high-level languages? H igh-level programming languages use code written in a way that is similar to a natural human language , such as English, making it easier to understand and use the language. Using high-level languages leads to fewer errors and allows for more powerful and complex commands compared to low-level languages. However, a high-level language must be translated into machine code (binary) before it can be run, as high-level languages cannot be executed directly by the CPU . Popular high-level languages: PYT HON C++ Ja v a Visual Basic Low-Level Languages Low-level languages do not closely resemble a natural human language , making it harder for humans to understand and write in. Low-level languages are used when a program must be executed quickly or when programmers need to write code that interacts directly with the hardware , such as device drivers. There are two types of low-level language : Machine Code This is the pure binary code that computers can directly process and execute . It is extremely tedious and difficult for humans to understand and write machine code. However, machine code can be used when a programmer needs to perform a very specific command that can't be done in a high-level language. Machine code will be executed faster than high-level programs because it is already in a format the CPU can execute and does not need to be translated . 0010 1011 0101 0101 0110 0111 0101 0001 0101 0101 0101 0100 1010 1010 1010 1010 1111 1110 0010 1001 0100 1001 0010 0111 0111 0101 0011 1010 1000 0101 0110 0111 0000 1010 1010 0011 1101 1001 0010 1101 0010 0100 1001 0011 1010 1001 0101 0101 0010 0101 0111 0101 0101 1000 1011 0111 Assembly Language Assembly language uses specialised command mnemonics to perform actions . See the Assembly Language section in the programming tab for a list of mnemonics such as INP , OUT and HLT . Assembly language is preferred by many programmers over machine code because it is easier to understand and spot errors . It is faster to execute than high-level languages and, like machine code, can be used to directly control the CPU . Q uesto's Q uestions 7.1 - Language Levels: 1a. Describe three reasons why programmers use high-level languages . [ 3 ] 1b. Explain one limitation of using high-level languages . [2 ] 2a. Describe a key difference between low-level languages and high-level languages . [ 2 ] 2b. Describe when a low-level language would be used instead of a high-level language . [2 ] 2c. Describe an advantage and a disadvantage of writing directly in machine code . [2 ] 2d. Describe what assembly language is. Give one benefit to using assembly language instead of machine code and one benefit to using it instead of a high-level language . [3 ] 3. Compare high-level and low-level languages by stating which is: a. Easier to understand [ 1 ] b. Requiring translation [ 1 ] c. Quicker to execute [ 1 ] INP STA Number1 OUT HLT Number1 DAT 6.2 - Utility Software Theory Topics 8.1 - Programming Principles

Based on the OCR Computer Science A-Level 2015 specification. Exam Board: OCR 3.1e - Sorting Algorithms Specification: A-Level 2015 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 This page is still being updated. Graphical Processing Unit What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Multicore & Parallel Systems What is cache memory? Cache memory is temporary storage for frequently accessed data . Cache memory is very quick to access because it is closer to the CPU than other types of memory like RAM . Q uesto's Q uestions 3.1e - Sorting Algorithms: 1. What is cache memory ? [ 2 ] 3.1d - Trees & Graphs Theory Topics 3.1f - Searching Algorithms

Based on the OCR Computer Science A-Level 2015 specification. Exam Board: OCR 1.1a: The CPU & The FDE Cycle Specification: A-Level 2015 The Central Processing Unit ( CPU ) is the most important component in any computer system. The purpose of the CPU is to process data and instructions by constantly repeating the fetch - decode - execute cycle . CPU Components The control unit directs the flow of data and information into the CPU. It also controls the other parts of the CPU . ALU stands for ‘ Arithmetic and Logic Unit ’. It performs simple calculations and logical operations . The registers are temporary storage spaces for data and instructions inside the CPU . The registers are used during the FDE cycle . Five essential registers are explained below. Important Registers A register is a small storage space for temporary data in the CPU . Each register has a specific role . There are five essential registers used in the FDE cycle : Program Counter (PC) A register that tracks the RAM address of the next instruction to be fetched . Memory Address Register (MAR) A register that tracks the RAM address of data that is currently being accessed . Memory Data Register (MDR) The MDR stores the data that is transferred from RAM to the CPU . Current Instruction Register (CIR) A register that stores the instruction that has been fetched from RAM , and is about to be decoded or executed . Accumulator (ACC) The ACC stores the result of executions performed in the FDE cycle . The FDE Cycle The essential idea of the FDE cycle is that instructions are fetched from RAM , to be decoded (understood) and executed (processed) by the CPU . The Fetch - Decode - Execute (FDE) cycle is performed by the CPU millions of times every second. This cycle is how the CPU processes data and instructions for each program or service that requires its attention. 1. 2. 3. The Program Counter (PC ) register displays the address in RAM of the next instruction to be processed . This value is copied into the Memory Address Register (MAR ). 0054 The PC register is increased by 1 . This prepares the CPU for the next instruction to be fetched. 0055 The CPU checks the address in RAM which matches the address held in the MAR . 0054 4. The instruction in RAM is transferred to the Memory Data Register (MDR ). MDR 5. The instruction in the MDR is copied into the Current Instruction Register (CIR ). MDR CIR 6. The instruction in the CIR is decoded (understood) and executed (processed). Any result of an execution is stored in the Accumulator (ACC ) register. CIR ACC 7. The cycle repeats by returning to the first step and checking the program counter for the address of the next instruction . Buses Data is transferred within a computer system along pathways called buses . There are three types of bus: Address Bus Sends a memory address of where data is stored. The address is sent from the CPU to RAM in the FDE cycle. Data Bus Transfers data between components. Data is sent both ways . Control Bus Sends control signals from the control unit to other components of the system. Status signals are sent back to the CPU. Think about which buses would be used during the FDE cycle and when. For example, look back at stages 3 and 4 of the FDE cycle above. The address bus is used to send the address in RAM of the next instruction . The control bus is used to send the fetch signal . The data bus is used to transfer the instruction from RAM to the MDR . Computer Architecture The way a computer is designed and internally organised is known as its architecture . The most common type of computer architecture is Von Neumann architecture . Von Neumann Architecture The key features of Von Neumann architecture include: The CPU , which constantly performs the FDE cycle , and contains: One control unit One ALU Special registers D ata and instructions are stored in the same format in the same area in memory . Instructions are commands and data are the specific values used when processing. Data and instructions are transferred across buses (pathways) between the CPU, memory and input or output devices. Harvard Architecture The key features of Harvard architecture include: The CPU , which constantly performs the FDE cycle , and contains: One control unit One ALU D ata and instructions are stored in separate areas in memory . Instructions are commands and data are the specific values used when processing. Data and instructions are transferred across buses (pathways) between the CPU, data memory, instruction memory and input or output devices. Q uesto's Q uestions 1.1a - The Central Processing Unit (CPU): 1a. What does 'CPU ' stand for ? [1 ] 1b. What is the purpose of the CPU ? [ 2 ] 2a. Draw a diagram of the CPU , use the same symbols as shown on this page. [ 4 ] 2b. Label the three main components of the CPU. [ 4 ] 3. Describe the purpose of: a. The Control Unit [ 2 ] b. The ALU [ 2 ] c. The registers [ 2 ] 4a. Describe the key features of Von Neumann architecture . [ 3 ] 4b. Describe the differences between the two main types of architecture. [ 2 ] This page is still being updated. Theory Topics 1.1b - Performance

Learn about the different types of applications software including productivity programs, business tools and IDEs. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 2.2: Applications Software Exam Board: OCR Specification: 2016 - Unit 1 What is applications software? Don't confuse applications software and apps . Apps generally have a single purpose , such as a game like Angry Birds or the torch tool on a phone. Applications software can be used for a number of different functions depending on the user's needs and their purpose. Productivity Software This is general use software for completing a range of tasks accurately and efficiently . Key examples include word processors (e.g. Microsoft Word or Google Docs), presentation software (e.g. Microsoft PowerPoint or Google Slides) and web browsers (e.g. Microsoft Edge or Google Chrome). Email applications (e.g. Microsoft Outlook or Gmail) are beneficial to organisations because staff can send information to many customers at once which is a simpler and less costly method of communication than something like sending letters or leaflets in the mail. Emails can also include attachments of important documents and include multimedia elements like images and videos to make communication more interesting . Databases and Spreadsheets Database tables and spreadsheets can store both numerical and textual data ready for analysis . Examples include simple database tables and financial spreadsheets of a company's profits each year. Microsoft Access is an example of database software that uses tables of records and Microsoft Excel is an example of spreadsheet software . Data can be sorted numerically or alphabetically for both software types but graphs can be created from spreadsheets to visualise data . When using spreadsheets (or databases) records can be locked ('record locking' ) so that only one person can make edits to a specific record at any one time. Edits will be saved before unlocking the file. This will stop data being incorrectly overwritten and will ensure that the data in the spreadsheet is up-to-date, accurate and fit for purpose. Development Tools These are tools for programmers who are creating or modifying software . An integrated development environment ( IDE ) is software used to create , edit and debug (fix) programs . An IDE features a number of tools , including: A source code editor to type program code into. It may contain features such as error highlighting and automatic formatting . Because IDEs use high-level languages like Python or Java , a translator is required to convert the source code into machine code ( binary ) so that it can be understood and processed by the CPU . A compiler is a type of translator that converts instructions into machine code (binary) in one go . An interpreter is a type of translator that converts instructions into machine code (binary) line by line . A debugger is used to test code and display errors . Other development tools aid programmers with developing and maintaining websites and apps for phones / tablets. An advantage of databases over spreadsheets is that data can be atomised - meaning it can be stored in separate tables (e.g. one for patients and one for doctors ) with records linked through relationships . This minimises data redundancy (duplication ), meaning there is a lower chance of making errors , and it is easier to search through the table as each record will only appear once . A search through a database is called a 'query '. Business Software This is specialist software for businesses , often made bespoke for an organisation based on their needs . Types of business software: Project management software allows teams of workers to collaborate and split large projects into manageable tasks with clear deadlines and assigned roles . A management information system (MIS ) processes a large amount of data and organises it for use in decision-making and general data analysis . See more about an MIS in section 3.5 . Multimedia programs such as video editors or animation suites can be used to create high-quality videos with images , audio and video clips . Collaboration tools for businesses allow employees to share ideas and resources in real-time . Publishing software allows users to implement text and images into eye-catching designs such as posters , leaflets or static adverts to include on a website. Expert systems use large databases for automatic decision-making , often making use of AI to quickly solve complex problems . A healthcare example of an expert system is a medical diagnosis program that may suggest possible illnesses when a patient's symptoms are input . CAD / CAM One example of business software used for the design and manufacture of a product is CAD / CAM (C omputer-A ided D esign / C omputer-A ided M anufacturing). CAD is used to create highly detailed digital designs and CAM translates these designs into instructions for manufacturing machines to make the product physically. These software packages use 3D modelling and image rendering along with exact measurements to create precise designs ready to be manufactured . Engineers use them to design and make mechanical parts and architects use them to create detailed building models and blueprints . Q uesto's Q uestions 2.2 - Applications Software: 1. State four different kinds of productivity software and briefly describe how each could be used . For example: "Word processors can be used to type up a letter in an office or write an essay for school." [8 ] 2. Describe two differences between database and spreadsheet software. [2 ] 3a. What is an Integrated Development Environment ? [1 ] 3b. Describe three tools used in an IDE. [6 ] 4. Giving brief examples of how they can be used, state four different types of business software . [8 ] 5. Suggest how a website design company could use each of the three types of applications software (Productivity Software , Development Tools and Business Software ). [ 6 ] 2.1 - Types of Software Topic List 2.3 - Utility Software