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  • OCR A-Level Computer Science | CSNewbs

    OCR A-Level Computer Science These pages cover content from the . OCR A-Level Computer Science 2015 specification Component 1 - Computer Systems 1 ( ) Computer Hardware 1.1 - The CPU & The FDE Cycle 1.2 - Performance 1.3 - Processors 1.4 - Input & Output Devices 1.5 - Memory & Storage 2 ( ) Computer Software 2.1 - Operating Systems 2.2 - Systems Software 2.3 - Applications Software 2.4 - Translators & Compilation 2.5 - Software Development Methodologies 2.6 - Programming Paradigms 2.7 - Assembly Language 2.8 - Object-Oriented Language 4 ( Data & Logic ) 4.1 - Number Systems 4.2 - Signed Binary 4.3 - Binary Calculations 4.4 - Floating Point 4.5 - Shifts and Masks 4.6 - Character Sets & Data Types 4.7 - Data Structures 4.8 - Logical Operators & Truth Tables 4.9 - Flip Flops, Adders, Laws & Maps 5 ( ) Laws & Issues 5.1 - Legislation 5.2 - Ethical Issues 3 ( ) Networks & Databases 3.1 - Compression 3.2 - Encryption & Hashing 3.3 - Databases 3.4 - SQL & Normalisation 3.5 - Network Characteristics 3.6 - Protocols & TCP/IP Stack 3.7 - Topology & DNS 3.8 - Network Security & Threats 3.9 - Web Technologies 3.10 - HTML, CSS & Javascript

  • 1.7 - Additional Hardware - Eduqas GCSE (2016 Spec) | CSNewbs

    1.7: Additional Hardware Exam Board: Eduqas / WJEC Specification: 2016 + 1.7a - Internal Hardware Motherboard The motherboard is the , unique for each device. It holds and , between them. main circuit board of a computer connects the different components together allowing data to be transferred Components such as the CPU and ROM are to the motherboard. directly attached The motherboard has (i.e. sound cards) and ports (i.e. USB). expansion slots for additional cards Graphics Processing Unit (GPU) Sound Card A is a microprocessor that to to be . GPU performs complex calculations generate graphical images displayed on a monitor ​ There are two types of GPU, GPUs within the circuitry or GPUs on an (known as a 'graphics card'). integrated motherboard dedicated additional card ​ An is cheaper and generates less power because it . Integrated GPUs are used in tablets and laptops as they generate less heat and are optimal for general computing uses (e.g. web browsing or watching movies). integrated GPU uses the RAM of the computer ​ A is more expensive and generates more heat, often requiring a fan because it . Dedicated cards are used by animation professionals and professional gamers who require the best graphics. dedicated GPU contains its own memory Sound cards into when through a microphone.​ convert analogue sound waves digital data (binary) inputting audio 0010 1011 0101 0101 0110 0111 0101 0001 0101 0010 1011 0101 0101 0110 0111 0101 0001 0101 Sound cards also into to through speakers or headphones. convert digital data (binary) analogue sound waves output audio 1.7b - Embedded Systems A has a that manages the different program cycles. Example: washing machine control chip An embedded system is a to provide a . computer system built into a larger machine 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 A has a that determines when to change to a green or red light. Example: traffic light control chip 1.7c - Input & Output Devices are used by humans to , through methods such as , or . Input devices interact with a computer system text voice touch ​ show the , such as , or a on a monitor. Output devices result of computer processing sound printed text visual display ​ , such as a USB stick or an external hard drive, are neither input nor output devices - see . Storage devices 1.4 Input Devices These are just some of the more common input devices . A mouse and a keyboard have been described in further detail. Are there any devices below you haven't heard of before? Mouse Benefits: Easy to navigate a graphical user interface. A wireless mouse takes up less space . (e.g. in a video game). Faster to select options Drawbacks: Difficult to use for people with restricted hand movement . Difficult to use on some surfaces . Other input devices: ​ Scanner Controller Microphone Webcam Chip Reader OCR Scanner OMR Scanner Barcode Scanner Graphics Tablet (e.g. light or temperature) Sensors Touch Screen Remote Control (e.g. fingerprint or iris) Biometric Scanner Concept Keyboard Sip / Puff Switch Keyboard Benefits: . Quick to input text with a on most keyboards. Easy to use familiar layout Keys can be customised and shortcuts can be used . Drawbacks: Takes up a large amount of space on a desk. Difficult for people to use with restricted hand movement or poor eyesight . Output Devices Monitor These are just some of the more common output devices . ​ A monitor and a printer have been described in further detail. Are there any devices below you haven't heard of before? ​ Other output devices: ​ Plotter Speakers Projector Alarm Light Headphones Touch Screen Braille Terminal What is it? A monitor is required to see the result of human input and computer processing . Monitors can be bought in different sizes and resolutions for a range of purposes such as video editing or playing games . Monitors can be changed to alter the . settings brightness or contrast Printer What is it? A printer uses ink or toner to print a document (such as text or images) onto paper . Inkjet printers use ink cartridges , are generally slower and print in a lower quality . Laser printers use toner cartridges and are generally quicker and print to a higher quality . uesto's uestions Q Q 1.7 - Additional Hardware: 1.7a - Internal Hardware What is the purpose of the ? [ 1. motherboard 2 ] ​ What is the purpose of the ? [ 2a. GPU 2 ] 2b. Describe two differences between . [ integrated and dedicated expansion cards ] 4 ​ 3. Explain how a sound card works. [ 4 ] ​ 1.7b - Embedded Systems What is an ? [ ] 1. embedded system 3 ​ Give two of an embedded system. [ 2a. examples 2 ] Research and describe of an embedded system. [ 2b. another example 2 ] ​ 1.7c - Input & Out[ut Devices Choose and describe at least and of using each one. [ 1. four input devices two benefits two drawbacks 8 ] ​ Describe . [ 2. three output devices 3 ] ​ Justify which would be in the following scenarios: 3. input and output devices most suitable A teacher needs to . a. take the class register [ 4 ] A with their cousins in Australia. b. family want to communicate [ 4 ] The wants to play Star Wars in the assembly hall. c. school movie club [ 4 ] An e-sports player is taking part in an . [ d. online multiplayer tournament 4 ] A so that only registered scientists can enter. e. laboratory needs security [ 4 ] 1.6 - Buses & Instruction Sets 2.1 - Logical Operators Theory Topics

  • OCR CTech IT | Unit 1 | 3.2 - Virtualisation | CSNewbs

    3.2 - Virtualisation Exam Board: OCR Specification: 2016 - Unit 1 What is virtualisation? describes the of a device, software or server. Virtualisation creation of a virtual version combines multiple storage devices so that they appear to be just one device. Storage virtualisation allows one physical server to host multiple virtual machines, each running separately. Server virtualisation Virtual Client Think back to the from . A is a full desktop environment where the . For example, where an operating system is managed and hosted centrally but displayed on a different computer (dumb client). hypervisor 3.1 virtual client processing happens remotely locally ​ A problem with virtual clients is that users will be and an for each client. unable to work if network connectivity is lost, increased load on the server might result in poor performance ​ A common use of virtualisation is in testing applications within a secure environment before they are used with the main system. Virtual Clients Benefits & Drawbacks of Virtualisation Benefits of virtualisation: ​ Costs are because money is saved by . Money is also saved due to and . cheaper in the long-term not purchasing multiple physical devices less cabling 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 before main-system deployment. tested in a secure environment ​ because only the server needs to be fixed. Simplified response to recover after a disaster Drawbacks of virtualisation: ​ If not set up efficiently, users , as fewer servers do more work. could face serious performance issues ​ If a single , the . physical system fails impact will be greater ​ , requires and can cost a lot. Initial set up is complex technical knowledge ​ as the data is stored in the same place. Easier for hackers to take more information at once Cloud Technology 'The cloud' is storage that is , primarily the internet. A is an example of as data may be stored across multiple physical devices. There are three different types of cloud storage: accessed through a network cloud server storage virtualisation is where a business will have its that can be accessed by employees. This allows for flexible and convenient data storage and gives the . Users of the private cloud will not usually have to pay individually for access - but the company will need to spend . Private cloud own data centre business control over data management and security a lot of money on set up and maintenance uses such as Google Drive or DropBox to provide storage . Public cloud is usually a , where businesses will pay for specific amounts that they need. and the providing constant access and deploying effective security measures. Public cloud third-party service providers over the internet pay-for-use service Data management and data security is maintained by the cloud provider business is dependent on them uses a mix of . Organisations can between private and public clouds as their specific . A benefit of hybrid cloud is that it gives an organisation more flexibility and data storage options. As an example, a company could use on-site or private cloud storage to and third-party, public cloud services to . Hybrid cloud on-site storage (private cloud) and third-party (public cloud) services move workloads needs and costs change hold sensitive information hold less important data uesto's uestions Q Q 3.2 - Virtualisation: 1. What is the difference between server and storage virtualisation ? [ 2 ] 2. What is a virtual client ? [ 1 ] ​ Explain the 3. advantages and disadvantages of using virtualisation. [ 16 ] ​ 4. Describe the differences between private , public and hybrid cloud storage. [ 6 ] 3.1 - Server Types Topic List 3.3 - Network Characteristics

  • Python | 3a - Data Types | CSNewbs

    Python 3a - Data Types Data Types in Python If you are a Computer Science student you need to know about the different data types that are used in programming. ​ ​String – A sequence of alphanumeric characters (e.g. “Hello!” or “Toy Story 4” or “Boeing 747” ) Integer – A whole number (e.g. -120 or 0 or 340) Float (also called Real ) – A decimal number (e.g. -32.12 or 3.14) Boolean – A logical operation (True or False) Character – A single alphanumeric character (e.g. “a” or “6” or “?”) [ Not used in Python as it would just be a string with a length of 1] Converting to Another Data Type You can by overwriting the variable with a different data type. convert a variable from one type to another = On line 1 the variable value of miles is 45.4 (a - decimal number). float ​ On line 2 the variable data type has been turned into an integer using the ( ) command. int ​ Because an integer is a whole number, when miles is printed on line 3 it displays 45 with no decimal places. ​ Other Conversions ​ ( ) converts a variable to a . str string ​ ( ) converts a variable to a (decimal number). float float Practice Task 1. Ask the user to a whole number (integer). input 2. Convert the number into a float. 3. Print the number. Example solution: Section 2 Practice Tasks 3b - Calculations

  • Python | 6b - While Loops | CSNewbs

    Python 6B - While Loops Types of Loop The third (after Sequence and Selection) is . If you iterate something, then you it. construct of programming Iteration repeat ​ There are two key loops to use in Python: and . for loops while loops ​ A – e.g. “For 10 seconds I will jump up and down”. The . for loop is count controlled loop will continue until the count (e.g. 10 seconds) has finished ​ A – e.g. “While I am not out of breath, I will jump up and down.” The . while loop is condition controlled loop will continue until the condition is no longer true Simple While Loops A while loop keeps and is . repeating until the starting condition has been broken no longer true ​ In the example below, a number will continue to be increased by 1 inside of the loop it is no longer less than 11, then the loop ends. until It is important to . I have assigned number as 1. give the variable a value before you start the while loop ​ The last line otherwise the number would stay at 1 and the . increases the number by 1 loop would repeat forever Practice Task 1 Time to create a simple program using a while loop. Use the example above to help you. ​ Start with a number variable that equals 15. ​ While the number is above 0 print the number and keep taking away 1 each turn. Example solution: Inputs Inside While Loops If you want the user to keep entering an input until they give a certain answer then you need to put the input inside the while loop: I also have put before the loop because Python needs to know the value of the variable before it checks to see if it is not equal to July. month = ” ” I chose a so that it does not interfere with the program. default value of just a blank space ​ That is an important concept. We need to feed Python a default value if we are not going to refer to the variable in the while loop until it is first used inside of the loop (like the month example above). If we are using strings the default value should be a blank space like below: Or if we are using in a while loop then we need to make our variable equal a before we use it: numbers default value such as 0 Practice Task 2 1. Set a variable called total to equal 0. While total is not equal (!=) to 4 ask the user to input a guess for a number between 1 and 10. Make sure that your input line is indented inside of the while loop, not before or after. 2. Set a variable called name to equal ” “. While name is not equal to Iron Man add an input line that asks “Who is Tony Stark better known as?”. Example solution for #1: While True, Continue & Break Typing (true must be uppercase) will . while True loop indefinitely ​ The command is used to stop the . The command is used to . break loop continue restart the loop ​ The example below uses a loop to repeatedly ask the user to select 1, 2 or 3: Entering lets them and then (repeats). 1 input a number continue Entering displays a and then (repeats). 2 total continues Entering will (stop) the loop. 3 break Practice Task 3 Create a while True loop that asks the user to enter a number. Add the number to a total variable and print it. When the total reaches 100 or more, stop the program. Example solution: 6a - For Loops Section 6 Practice Tasks

  • OCR CTech IT | Unit 1 | 2.6 - Software Troubleshooting | CSNewbs

    2.6 - Software Troubleshooting Exam Board: OCR Specification: 2016 - Unit 1 A software error occurs when a as expected. program or process stops working ​ ​ Software errors usually occur when programs are badly written or if a user inputs unexpected data .​ Common Faults System Freeze The computer and pressing keys or moving the mouse shows . Commonly caused by a . freezes no response software bug or virus Unexpected Reboot To try and fix errors, a computer might get stuck in an of booting and rebooting. Other systems may frequently . endless loop restart without warning Stop Error This occurs after a fatal system error when the , usually because of a . Commonly known as the ' operating system stops driver software issue blue screen of death ' on Windows-based systems. Update Error While designed to fix errors, can sometimes bring more problems if they . updates interfere with the current software Troubleshooting Tools for Software Errors Event Viewer (Logs) If a software error does occur then the same characteristics as a hardware error should be logged , such as the time / date of the error, the user logged in, problem history etc. Memory Dump Copies and displays the contents of RAM at the time of a crash to help a technician discover what happened . Baselines Before After A comparison of what the system is like after a crash compared to a fixed point in time beforehand. The baseline can be used to see differences which may have caused the computer to fail. Anti-Virus Checks if is running on a system and using up resources and slowing the system down. It could then be by the anti-virus. malware quarantined and deleted Installable tools can also be downloaded to and find the . investigate the system cause of the problem uesto's uestions Q Q 2.6 - Software Troubleshooting: ​ Describe each of the four common types of : 1. software error a. System Freeze b. Stop Error c. Unexpected Reboot [ d. Update Error 2 each ] ​ Describe each type of and explain how it can be software errors. 2. troubleshooting tool used to discover and fix a. Event Viewer b. Memory Dump c. Baselines d. Antivirus Software e. Installable Tools [ 2 each ] 2.5 Communication Methods Topic List 2.7 - Protocols

  • HTML Guide 4 - Hyperlinks | CSNewbs

    4. Hyperlinks HTML Guide A hyperlink is a link to another web page . ​ In this section, you will link your page to a real website, like Wikipedia. ​ Hyperlinks require the anchor tags and Copy a URL Firstly you need to of the web page that you would like to link your page to. copy the full web address Choose an appropriate web page that relates to your chosen topic. Create the Anchor Tag 4. Close the start of the . tag 1. Open the start of the . tag (stands for ). 2. Type href hypertext reference 3. Paste the URL inside speech marks . 5. Type the text you want the user to click on . 6. Time to . close the tag When you save your webpage and run it in a browser you will be able to click highlighted text to open the website you have chosen. Add at least three different hyperlinks to your webpage. Try to add the 2nd & 3rd links without looking at this page - practise makes perfect. Add a Hyperlink within a Sentence You can also create an anchor tag within a sentence. Hyperlinks are important to link webpages together. ​ Next is time for adding pictures! Either change one of your previous hyperlinks to be in the middle of a sentence or create a new one. 3. Text Tags HTML Guide 5. Images

  • 6.1 - Operating Systems - Eduqas GCSE (2020 Spec) | CSNewbs

    6.1: Operating Systems Exam Board: Eduqas / WJEC Specification: 2020 + What is an Operating System? An ( ) is . operating system OS software that helps to manage the resources of a computer system There are of an operating system: eight main roles Manage the CPU A critical role of the OS is to so that can be . manage the CPU applications and processes run efficiently ​ The CPU is effectively managed by performing three further roles: Manage Memory (RAM) The OS for stored into. The to carry out the instructions. reserves memory space in RAM programs to be copied FDE cycle is executed continuously ​ The OS also ensures that programs are appropriately managed so that data is and . stored in correct memory locations not corrupted Manage Interrupts A interrupt is an alert signal sent to the CPU when an application or hardware device requires immediate attention . The OS must efficiently manage interrupts so that a problem can be dealt with quickly if one occurs. Manage Multi-Tasking The OS manages tasks so instructions can be executed by - this is called . the CPU in turn scheduling The OS with others and crashing. Tasks should even though only one process can be executed at a time. prevents processes from interfering appear to run simultaneously Manage Backing Store The is another term for such as the magnetic , optical drives or solid state memory sticks. backing store secondary storage devices hard disk drive ​ The OS ensures data is stored correctly and can be from the backing store. efficiently retrieved Files are organised in a hierarchical (logical) structure . Manage Peripherals A is an connected to a computer system to or . peripheral external device input output data The OS manages the (such as a keyboard or mouse) and the (such as a monitor or speaker). receiving of data from input devices transfer of data to output devices Manage Security The OS a llows users to with different permissions. It also permits multiple users to . create, manage and delete accounts log in and change passwords ​ and software is managed by the OS as well as some processes. Antivirus firewall data encryption Manage the User Interface The final function of an operating system is to provide a . The most common type of user interface is a ( ) which can be presented in the following ways: user interface graphical user interface GUI are displayed to represent to applications and files. Icons shortcuts can be opened at the same time and switched between. Multiple windows A is displayed and allowing for , , and data. folder and file system manipulated copying searching sorting deleting The interface can be , such as changing font sizes and the . customised desktop background The taskbar allows shortcuts to be pinned for quick access . Menus can be opened from the Start button to display files and shortcuts. can be accessed such as . System settings network and hardware options Other types of user interface do exist, such as a ( ). This type of interface is and requires users to interact with the system by . This is a process and mistakes could easily accidentally delete data. There are many commands to learn so only who have been o learn this interface will be able to efficiently make use of it. command-line interface CLI entirely text-based typing commands complicated experts trained t uesto's uestions Q Q 6.1 - Operating Systems: ​ 1. Describe each role of the operating system : 1. Manage the CPU [ 2 ] 2. Manage memory [ 2 ] 3. Manage interrupts [ 2 ] 4. Manage multi-tasking [ 2 ] 5. Manage backing store [ 2 ] 6. Manage peripherals [ 2 ] 7. Manage security [ 2 ] 8. Manage the user interface [ 2 ] ​ [ 2. Describe 5 different ways the operating system can provide a user interface . 5 ] 5.1 - Data Structures Theory Topics 6.2 - Utility Software

  • Greenfoot Guide #3 | Movement | CSNewbs

    3. Move with Arrow keys Greenfoot Home Right-click on your main character object and select ' Open editor '. ​ The editor allows you to write different methods - actions that the class can perform. ​ The act() method will repeat whenever the Run button is pressed. 1. Open the Code Editor 2. Copy the Code CAREFULLY You need to use an to check if a certain key (like the right arrow key) is being pressed down. if statement ​ An if statement must be contained in . After each if statement, the proceeding code must be typed within - see the . standard brackets curly brackets image on the left ​ - If the then use the ( and ) Tip brackets are on the same line standard brackets ​ If the then use brackets are on different lines curly brackets { and } 3. Compile (Save) the Code Click the button at the . Compile top of the code editor ​ Then you can go back to the main window and click . Run Next ->

  • 3.1 - Data vs Information | Unit 2 | OCR Cambridge Technicals | CSNewbs

    3.1 - Data vs. Information Exam Board: OCR Specification: 2016 - Unit 2 The terms ' and ' ' are often used interchangeably but they . ' data information do not mean the same thing The term refers to that have . ' ' data unprocessed facts or statistics no context ​ For example, is - it is a statistic that has no context. 53% data The term refers to , organised and structured . ' ' information data that has been processed into context ​ For example, is - it is data that has been given context (meaning). 53% of pumpkin stock was sold in 2019 information Data Processing Information uesto's uestions Q Q 3.1 - Data vs. Information: ​ , using , the . [ ] 1. Describe examples difference between data and information 4 2.4 - Information Management 3.2 & 3.3 - Information Categories Topic List

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