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  • 1.2 - Storage Media | Unit 2 | OCR Cambridge Technicals | CSNewbs

    1.2 - Storage Media Exam Board: OCR Specification: 2016 - Unit 2 Data can be stored on a variety of storage media , each with its own benefits and drawbacks . 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. Hard disk drives can also be external and connected through a USB port . An obsolete (no longer used) type of magnetic storage is a floppy disk but these have been replaced by solid state devices such as USB sticks which are much faster and have a much higher capacity.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 per gigabyte than solid state . ​ X - Not DURABLE and not very PORTABLE when powered on because moving it can damage the device. ​ ✓ - Relatively quick ACCESS SPEED but slower than Solid State . ​ 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 . ​ X - Optical discs have the Slowest ACCESS SPEED . ​ ​ Magnetic Disks are spelled with a k and Optical Discs have a c. Solid State Storage Paper 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 . SSDs can also be external . ​ 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. Paper storage includes printed or hand-written documents, notes, forms, schedules and maps. Paper is relatively inexpensive in small quantities but it can take up a lot of space compared to small devices like USB sticks. Producing paper is environmentally damaging and requires physical security methods to keep safe. ​ Paper, such as a timetable, can be written on if times change and easily carried on a person. However, paper in the form of an essay must be re-printed to add changes . Solid State Characteristics: ​ ✓ - High CAPACITY but more expensive 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 . Paper Storage Characteristics: ​ X - Low CAPACITY as each page can only hold a certain amount of information. Paper also takes up physical space . ​ X - Poor DURABILITY as paper can easily tear and become damaged in rain. ​ ✓ / X - PORTABILITY varies as single sheets of paper can be easily folded and placed in a pocket. However, large stacks of paper can be difficult and expensive to transport. ​ X - Paper's ACCESS SPEED , in terms of searching for a specific item, is slow , especially if the paper storage has not been organised efficiently . Q uesto's Q uestions 1.2 - Storage Media: ​ 1. State 3 examples of each type of storage media . For example, a CD for optical storage. [3 each ] ​ 2. Compare each type of storage media in terms of capacity , durability , portability and access speed . You may decide to do this as a table or poster. [16 ] ​ 3. Identify the most suitable device (not the media ) and justify its suitability for the following scenarios: a. Backing up a large database at the end of each day. [5 ] b. Keeping a copy of a cleaning schedule for hotel staff. [5 ] c. Making copies of a promotional video to hand out to audience members at a dancing event. [5 ] 1.1 - Holders of Information Topic List 1.3 - Access & Storage Devices

  • 2.2.2a - Computational Methods | OCR A-Level | CSNewbs

    Exam Board: OCR 2.2a - Computational Methods 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 2.2a - Computational Thinking: ​ 1. What is cache memory ? [ 2 ] ​ 2.1b - Modularity & IDE Theory Topics 2.2b - Object Oriented Programming

  • 2.4c - Object-Oriented Language | OCR A-Level | CSNewbs

    Exam Board: OCR 2.4c: Object-Oriented Language 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 2.4c - Object-Oriented Language: ​ 1. What is cache memory ? [ 2 ] ​ 2.4b - Assembly Language Theory Topics 3.1a - Compression

  • Python | Extended Task 6 | CSNewbs

    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) ➡

  • 6.2 - Utility Software - Eduqas GCSE (2020 Spec) | CSNewbs

    6.2: Utility Software Exam Board: Eduqas / WJEC Specification: 2020 + What is utility software? Utility software are dedicated programs used for the maintenance and organisation of a computer system. Antivirus Antivirus software is used to locate and delete viruses on a computer system. The antivirus scans each file on the computer and compares it against a database of known viruses . Files with similar features to viruses in the database are identified and deleted . Firewall A firewall manages incoming and outgoing network traffic . Each data packet is processed to check whether it should be given access to the network by examining the source and destination address . ​ Unexpected data packets will be filtered out and not accepted to the network. Disk Defragmenter As files are edited over time they will become fragmented - this is when the file is split into parts that are stored in different locations on the hard disk drive . Files that are fragmented take longer to load and read because of the distance between the fragments of the file. Defragmentation software is used to rearrange the file on the hard disk drive so that all parts are together again in order. Defragmentation improves the speed of accessing data on the hard disk drive. Backup Software System backup copies data onto a separate storage device in case the original information is lost or corrupted . ​ Backups should be saved regularly and stored in a different location to the rest of the data. Magnetic tape is a common backup medium. ​ A typical backup policy is one known as 'grandfather - father - son' which uses three different backups at a time. Disk Compression Compression is the process of decreasing the size of a file . Disk compression is a utility tool that automatically compresses files when saved so that more data can be stored on the hard disk drive. When a file is to be opened, the program is automatically decompressed . Disk compression increases the amount of space on a hard disk drive but it takes longer to open and close files . Disk Checker ​ This utility is used to scan a hard drive for any corrupted data . ​ The corrupted data is deleted to speed up reading from and writing to the hard drive. ​ More advanced disk checkers are used to scan for bad sectors . A bad sector is a permanently damaged section of the hard drive which can no longer be used and must be skipped over. Disk Formatter Disk Partition Editor This utility tool prepares a storage device such as the hard disk drive to be used by removing the current data and creating a file system . A file system manages how data is stored and accessed . ​ Other devices like a USB stick may need to be formatted before they can be used for the first time . Within memory, partitions are segments of data that have been grouped together logically on the hard disk drive . ​ A disk partition editor allows a user to view and modify these memory partitions . Options include creating, editing and deleting partitions. Clipboard Manager The clipboard is a temporary storage space for copied data. For example, a large amount of text can be copied and stored on the clipboard to be pasted into another document, even when the original file has been closed . ​ The clipboard manager adds more functionality to the clipboard to allow multiple pieces of data to be copied, cut and pasted . System Profiles A system profiler displays detailed information about the applications on a computer system, as well as data about any attached hardware devices . ​ Information is provided and updated in real-time about the performance of software and internal components such as the CPU . Data Recovery Data recovery tools allow deleted, corrupted or otherwise inaccessible data to be returned to a usable state . ​ The data loss may have been caused by physical damage to a drive, corrupt memory partitions or accidental deletion . ​ Most data is not permanently removed when it is deleted so data recovery software can often be used to reaccess files . Revision Control Revision control software manages previous versions of an application so that if an error occurs the program can be returned to a previous state . ​ This is also called version control software and can be used to manage and monitor changes made to files over time. Archiver Archiving is the process of storing important data that is not currently required . It must not be deleted but it shouldn't take up valuable storage space either. ​ An archiver compresses multiple files using lossless compression into one folder . This archived folder can be stored on a computer system or transferred to a storage device and won't take up much space . Cryptographic Utilities A cryptographic utility is used to encrypt data so that it cannot be understood if intercepted . Encryption is commonly for data in transit - being sent between devices . ​ Cryptographic software can also encrypt data at rest - when stored on a hard disk drive for example - so that hackers would be unable to use the data . File Manager This utility tool provides an interface to the user for accessing, editing and moving files and folders on the system. ​ Programs will be displayed in a hierarchical ( ordered ) structure with icons representing the application logo or file type. ​ Files can be ordered in alphabetical, chronological or other orders and the manager provides an abstracted visualisation of where the data is stored. Q uesto's Q uestions 6.2 - Utility Software: ​ 1. What is meant by utility software ? [1 ] ​ 2. Describe each type of utility software : a. Antivirus b . Firewall c . Disk Defragmenter d . Backup Software e . Disk Compression f . Disk Checker g . Disk Formatter h . Disk Partition Editor i . Clipboard Manager j . System Profiles k . Data Recovery l . Revision Control m . Archiver n . Cryptographic Utilities o . File Manager [2 ] 6.1 - Operating Systems Theory Topics 7.1 - Language Levels

  • OCR A-Level Component 1 | CSNewbs

    OCR Computer Science A-Level Component 1: Computer Systems These pages are based on content from the OCR Computer Science 2015 specification . This website is in no way affiliated with OCR . 1. Hardware 1.1a - The CPU & FDE Cycle 1.1b - Performance 1.2 - Processors 1.3a - Input & Output Devices 1.3b - Memory & Storage 2. Software 2.1 - Operating Systems 2.2a - Applications & Utilities 2.2b - Translators & Compilation 2.3 - Software Development Methodologies 2.4a - Programming & Pseudocode 2.4b - Assembly Language 2.4c - Object-Oriented Language 3. Networks & Databases 3.1a - Compression 3.1b - Encryption & Hashing 3.2a - Databases & Normalisation 3.2b - SQL 3.3a - Network Characteristics 3.3b- Protocols & TCP-IP Stack 3.3c - Network Hardware & DNS 3.3d - Network Security & Threats 3.4a - Web Technologies 3.4b - HTML, CSS & JavaScript 4. Data & Logic 4.1a - Data Types & Character Sets 4.1b - Denary, Binary & Hexadecimal 4.1c - Signed Binary & Floating Point 4.1d - Binary Calculations 4.1e - Shifts & Masks 4.2 - Data Structures 4.3a - Logical Operators & Truth Tables 4.3b - Flip Flops, Adders, Laws & Maps 5. Laws 5.1 - Computer Legislation 5.2 - Moral & Ethical Issues

  • 1.1b - Registers & FE Cycle - OCR GCSE (J277 Spec) | CSNewbs

    1.1b: Registers & The F-E Cycle Exam Board: OCR Specification: J277 The Fetch - Execute (F - E) 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. Important Registers A register is a small storage space for temporary data in the CPU . Each register has a specific role . There are three essential registers used in the F-E 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 the instruction that is to be fetched . Memory Data Register (MDR) ​ The MDR stores the instruction that has been 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 mathematical or logical calculations . Fetch - Execute Cycle The essential idea of the F-E cycle is that instructions are fetched from RAM , to be decoded (understood) and executed (processed) by the CPU . 1. 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 2. The PC register is increased by 1 . ​ This prepares the CPU for the next instruction to be fetched. 0055 3. 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 ). 5. The instruction in the MDR is copied into the Current Instruction Register (CIR ). MDR 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 . Q uesto's Q uestions 1.1b - Registers & The F-E Cycle: ​ 1 . What is the purpose of the registers ? [1 ] ​ 2 . Describe the purpose of each register : a. The Program Counter (PC) [ 2 ] b. The Memory Address Register (MAR) [ 2 ] c. The Memory Data Register (MDR) [ 2 ] d. The Current Instruction Register (CIR) [ 2 ] e. The Accumulator (ACC) [ 2 ] ​ 3. Draw a diagram with icons and words to show the steps of the Fetch - Execute cycle . [7 ] 1.1a - The CPU Theory Topics 1.2 - CPU Performance

  • Python | 6b - While Loops | CSNewbs

    top Python 6B - While Loops Types of Loop The third construct of programming (after Sequence and Selection) is Iteration . If you iterate something, then you repeat it. ​ There are two key loops to use in Python: for loops and while loops . ​ A for loop is count controlled – e.g. “For 10 seconds I will jump up and down”. The loop will continue until the count (e.g. 10 seconds) has finished . ​ A while loop is condition controlled – e.g. “While I am not out of breath, I will jump up and down.” The loop will continue until the condition is no longer true . Simple While Loops A while loop keeps repeating until the starting condition has been broken and is no longer true . ​ In the example below, a number will continue to be increased by 1 inside of the loop until it is no longer less than 11, then the loop ends. It is important to give the variable a value before you start the while loop . I have assigned number as 1. ​ The last line increases the number by 1 otherwise the number would stay at 1 and the 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 month = ” ” 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. I chose a default value of just a blank space so that it does not interfere with the program. ​ 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 numbers in a while loop then we need to make our variable equal a default value such as 0 before we use it: 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 while True (true must be uppercase) will loop indefinitely . ​ The break command is used to stop the loop . The continue command is used to restart the loop . ​ The example below uses a loop to repeatedly ask the user to select 1, 2 or 3: Entering 1 lets them input a number and then continue (repeats). Entering 2 displays a total and then continues (repeats). Entering 3 will break (stop) the loop. 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 - F or Loops Section 6 Practice Tasks ➡

  • 1.1b - Performance | OCR A-Level | CSNewbs

    Exam Board: OCR 1.1b Performance Specification: A-Level 2015 The performance of a computer system is affected by four main factors: Cache Memory: Size & Levels 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 . What are the 3 levels of cache memory? Level 1 cache is the smallest level (less than a megabyte ) but it is also the fastest . Level 2 cache is larger than level 1 (up to 8 megabytes ) but slightly slower. Level 3 cache is located outside of the CPU core which makes it slower than the first two levels but it is much larger (up to 50 megabytes ). How does cache memory work? ​ When the CPU searches for data , it looks first in level 1 cache, then level 2 and then level 3 . If the data has been found , this is called a 'cache hit '. If the data is not found then the CPU searches in RAM instead which takes more time - this is called a 'cache miss '. How does cache memory improve performance? Cache memory is closer to the CPU than RAM , meaning that it can provide data and instructions to the CPU at a faster rate . ​ A computer with more cache memory (e.g. 8MB instead of 4MB) should have a higher performance because repeatedly used instructions can be stored and accessed faster . ​ Larger level 1 and level 2 cache sizes will improve a computer's performance as data can be accessed extremely quickly . What is the limitation of cache memory? Cache memory is costly, so most computers only have a small amount . ​ Multiple cache misses will result in data latency (delay) as information is accessed from RAM which is further away from the CPU. Clock Speed What is clock speed? Clock speed is the measure of how quickly a CPU can process instructions . ​ Clock speed is measured in Gigahertz (GHz) . A typical desktop computer might have a clock speed of 3.5 GHz . This means it can perform 3.5 billion cycles a second . How does clock speed improve performance? ​ The faster the clock speed, the faster the computer can perform the FDE cycle resulting in better performance because more instructions can be processed each second . How does overclocking and underclocking affect performance? Typical clock speed: 3.5 GHz Underclocking Overclocking 3.9 GHz 3.1 GHz Overclocking is when the computer's clock speed is increased higher than the recommended rate. ​ This will make the computer perform faster, but it can lead to overheating and could damage the machine . Underclocking is when the computer's clock speed is decreased lower than the recommended rate. ​ This will make the computer perform slower but will increase the lifespan of the machine . Number of Cores What is a core? ​ A core is a complete set of CPU components (control unit, ALU and registers). Each core is able to perform its own FDE cycle . ​ A multi-core CPU has more than one set of components within the same CPU. How does the number of cores improve performance? ​ In theory, a single-core processor can execute one instruction at a time , a dual-core processor can execute two instructions, and a quad-core can execute four instructions simultaneously . ​ Therefore, a computer with more cores will have a higher performance because it can process more instructions at once . What are the limitations of having more cores? ​ If one core is waiting for another core to finish processing, performance may not increase at all. ​ Some software is not written to make use of multiple cores , so it will not run any quicker on a multi-core computer. Pipelining What is pipelining? ​ Pipelining efficiently uses multiple cores or processors to perform different stages of the FDE cycle at the same time . Pipelining overlaps the processing of instructions to improve performance by increasing the amount of instructions that can be fetched, decoded and executed each second . ​ The first image to the right shows a processor not using pipelining whereby one instruction can only be fetched once the previous instruction has been fetched, decoded and executed. The second image shows how pipelining can be used to process multiple instructions during the same clock cycle . For example, in clock cycle 3 instruction X can be executed while instruction Y is decoded and instruction Z fetched. A simplified example of a processor not using pipelining. A simplified example of a processor using pipelining. What is the limitation of pipelining? ​ Certain instructions may not be able to be executed until other instructions have been fetched and decoded . This wait for other instructions may impact performance . Q uesto's Q uestions 1.1b - Performance: ​ Cache Size & Levels 1a. What is cache memory ? [ 2 ] 1b. Describe the three levels of cache memory , including the storage size and relative speed of each level. [ 6 ] 1c. Describe what is meant by a ' cache hit ' and a ' cache miss '. [ 2 ] 1d. Describe two ways that more c ache memory will mean performance is higher . [ 4 ] 1e. Explain why most computers only have a small amount of cache memory. [ 1 ] Clock Speed 2a. What is clock speed ? What is it measured in? [ 2 ] 2b. Explain how a higher clock speed improves performance . [ 2 ] 2c. Explain the terms 'overclocking ' and 'underclocking ' and explain the effects of both on the performance of a computer. [ 4 ] ​ Number of Cores 3a. What is a core ? [ 2 ] 3b. Explain why a quad-core processor should have a higher performance than a dual-core processor . [ 3 ] 3c. Explain two reasons why having more cores doesn't necessarily mean the performance will be better . [ 2 ] ​ Pipelining 4a. What is pipelining ? How does pipelining affect performance ? [ 4 ] 1.1a - The CPU & FDE Cycle Theory Topics 1.2 - Processors

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    Preparation is the key to success. I won't say "Good Luck", because luck won't make you pass an exam. Focus and effort will. Thanks sir, now let me use your awesome site.

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