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The list of topics in the 2020 OCR GCSE Computer Science specifications. OCR GCSE Computer Science (J277) These pages are based on the J277 OCR GCSE Computer Science specification . This website is in no way affiliated with OCR . Component One: Computer Systems Paper 1 Playlist on YouTube 1. Systems Architecture 1.1a - The CPU 1.1b - Registers & FE Cycle 1.2 - CPU Performance 1.3 - Embedded Systems 2. Memory & Storage 2.1 - Primary Storage 2.2 - Secondary Storage 2.3 - Units 2.4a - Number Systems 2.4b - Binary Addition & Shifts 2.4c - Character Storage 2.4d - Image Storage 2.4e - Sound Storage 2.5 - Compression 3. Networks 3.1a - Network Types & Performance 3.1b - Network Hardware & Internet 3.2a - Wired & Wireless networks 3.2b - Protocols & Layers 4. Network Security 4.1 - Network Threats 4.2 - Preventing Vulnerabilities 5. Systems Software 5.1 - Operating Systems 5.2 - Utility Software 6. Impacts 6.1a - Impacts of Technology 6.1b - Legislation Component Two: Computational Thinking, Algorithms and Programming Paper 2 Playlist on YouTube 1. Algorithms 1.1 - Computational Thinking 1.2 - Designing Algorithms 1.3 - Searching & Sorting Algorithms 2. Programming Fundamentals 2.1 - Programming Fundamentals 2.2 - Data Types 2.3 - Additional Programming Techniques 3. Producing Robust Programs 3.1 - Defensive Design 3.2 - Testing 4. Boolean Logic 4.1 - Boolean Logic 5. Languages & IDEs 5.1 - Languages & Translators 5.2 - Integrated Development Environment

The homepage for all content aimed at Key Stage 3 students studying Computer Science / IT including computer hardware, Python, App Inventor 2 and Cyber Security. Key Stage 3 Topics These topics are aimed at Year 7 - 9 students (11 - 14 year olds) studying computing. Hardware The Motherboard The CPU Memory Expansion Cards Python Basics 1. The Basics 2. Variables 3. Inputs 4. Calculations 5. Selection 6. Turtle 7. Link to GCSE Python Cyber Security Malware Phishing & Staying Safe Other Topics Desktop Publishing

Learn about what embedded systems are and examples of them. Based on the J277 OCR GCSE Computer Science specification (first taught from 2020 onwards). 1.3: Embedded Systems Exam Board: OCR Specification: J277 Watch on YouTube : Embedded Systems Example: A washing machine has a control chip that manages the different program cycles. An embedded system is a computer system built into a larger machine to provide a means of control . Embedded systems perform a specific pre-programmed task which is stored in ROM . An embedded system uses a combination of hardware and software . They perform only specific tasks and often have a small amount of storage and low processing power . Example: A traffic light has a control chip that determines when to change to a green or red light. Q uesto's Q uestions 1.3 - Embedded Software: 1. What is an embedded system ? [3 ] 2a. Give two examples of an embedded system. [ 2 ] 2b. Research and describe another two examples of an embedded system. [ 4 ] 1.2 - CPU Performance 2.1 - Primary Storage Theory Topics

Learn about the benefits and drawbacks of virtualization, as well as about cloud storage and virtual clients. Based on the 2016 OCR Cambridge Technicals Level 3 IT specification. 3.2 - Virtualisation Exam Board: OCR Specification: 2016 - Unit 1 What is virtualisation? Virtualisation is the creation of a virtual version of a device , software , operating system or server . These virtual versions can then be run on a different physical computer system , such as a powerful server . There are many different types of virtualisation . Storage virtualisation combines multiple separate storage devices into acting and appearing like a single , central storage system . Using storage virtualisation improves scalability as further devices can join the storage system if more space is required . It also simplifies the management of storage across the network. Server virtualisation allows one physical server to be divided into and host multiple virtual servers , each running separately . Each virtual server operates independently , handling its own operating system and applications . This allows for resources to be used more effectively and improves the scalability and versatility of the physical server . Client Virtualisation (Virtual Clients) Client virtualisation is when several virtual desktops are run on a single server - think back to the hypervisor from 3.1 . A virtual client is a full desktop environment where the processing happens remotely . For example, where an operating system is managed and hosted centrally but displayed locally on a different computer. These are often known as 'dumb clients ' because the server does the processing for it , meaning it can have minimal resources like a slow processor and little memory / storage . General Benefits & Drawbacks of Virtualisation Benefits of virtualisation: Costs are cheaper in the long-term because money is saved by not purchasing multiple physical devices . Money is also saved due to less cabling and lower power consumption . If set up efficiently, it can be used for higher performance at a lower cost - "Do more with less" . Programs can be tested in a secure environment before main-system deployment. Simplified response to recover after a disaster because only the server needs to be fixed. Drawbacks of virtualisation: If not set up efficiently, users could face serious performance issues , as fewer servers do more work. If a single physical system fails , the impact will be greater . Initial set up is complex , requires technical knowledge and can cost a lot. Easier for hackers to take more information at once as the data is stored in the same place. Benefits of client virtualisation: All data is stored in one central location , making backup and disaster planning easier to manage . The whole system can be managed , secured and updated from the server , rather than from each individual system. Hardware costs will be reduced because the virtual clients do not store or process their own data , meaning they can be of a low spec . Users can have multiple virtual machines and log in remotely (from anywhere with internet access ). Drawbacks of client virtualisation: Users will be unable to work if network connectivity is lost . There is a high strain on the server as the virtual clients do not store or process data themselves . An increased load on the server might result in poor performance for each client, especially with multiple connections . As the data is stored in one location , there are security risks of unauthorised access if the server is not adequately protected . Server Virtual Clients Cloud Technology 'The cloud ' is storage that is accessed through a network , primarily the internet. A cloud server is an example of storage virtualisation as data may be stored across multiple physical devices . There are three different types of cloud storage: Private cloud is where a business will have its own data centre that employees can access. This allows for flexible and convenient data storage and gives the business control over data management and security . Users of the private cloud will not usually have to pay individually for access - but the company will need to spend a lot of money on set up and maintenance . Public cloud uses third-party service providers such as Google Drive or DropBox to provide storage over the internet . Public cloud is usually a pay-for-use service , where businesses will pay for specific amounts that they need. Data management and data security is maintained by the cloud provider and the business is dependent on them providing constant access and deploying effective security measures. Hybrid cloud uses a mix of on-site storage (private cloud) and third-party (public cloud) services . Organisations can move workloads between private and public clouds as their specific needs and costs change . A benefit of hybrid cloud is that it gives an organisation greater flexibility and data storage options. As an example, a company could use on-site or private cloud storage to hold sensitive information and third-party, public cloud services to hold less important data . Q uesto's Q uestions 3.2 - Virtualisation: 1. What is the difference between server and storage virtualisation ? [ 2 ] 2a. What is a virtual client ? [ 1 ] 2b. What are the advantages and disadvantages of client virtualisation ? [ 8 ] 3. Explain any further general advantages and disadvantages of using virtualisation , not covered in your answer to 2b. [4 ] 4. Describe the differences between private , public and hybrid cloud storage. [6 ] 3.1 - Server Types Topic List 3.3 - Network Characteristics

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

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