Paper 1 2019 OCR

• Input Devices


  Microphone

  Buttons
• Output Devices


  Speakers

  LEDs

  Screen
• Embedded operating system


  System software/software used to manage the device which is built into the device itself

  Stored in the device’s ROM/cannot be changed, Specific to the hardware/purpose
• Multicore processor


  More than one processing unit in a (single) processor, which can independently process instructions simultaneously.
• Different types of Addressing

  Immediate addressing

  Indirect Addressing

  Indexed Addressing
• Immediate addressing


  Operand is the value to be used.
• Indirect Addressing

  Operand is the memory location holding a value representing the memory location to be used.
• Indexed Addressing 


  The Operand is added to contents of the index Register to get memory location of the value needed.
• Optical Media


  read/written to, using a laser − read/written onto a reflective surface − data is stored using pits and lands Plus example − Eg. Blu-Ray/CD
• Advantages of using optical media

  -Cheap to produce/buy

  − Capacity big enough to hold film

  − Robust enough to be used over long periods/ moved around

  − Portable

  − Does not need an internet connection
• Purpose of a device driver

  A program that enables communication between an operating system and a (hardware) device
• Advantages and disadvantages between downloaded/ stream film and having a physical copy

  Advantages − Can access film (and indeed entire library) from anywhere with an internet connection − No physical storage needed − No risk of films being stolen/damaged/lost − Optical/disk player hardware not required to play film

  Disadvantage − Reliant on having an (fast enough) internet connection. − Need enough storage for download − Reliant on servers of the company providing the connection. − People like having a physical copy − If the company providing the stream goes out of business, copy is lost.
• Why compression is important for the streaming of high-resolution films


  -High resolution videos take up large amounts of memory/RAM

  − Due to the large number of pixels that need to be represented − When streaming, the data being sent is time sensitive/ sufficient data (i.e. the next chunk of video) needs to be received and processed within a given amount of time
• Why compression is important for the streaming of high-resolution films

  − Otherwise there will be pauses/buffering.

  − Compression reduces the amount of data that needs to be sent/bandwidth needed

  − Compression reduces the cost/data usage for those with download limits
• Example of Data structure that could be used to store single site's details

  tuple / record / list
• Tuple - A collection of items enclosed by parentheses, separated by commas. The items can be of different types. Tuple elements are accessed by their position in the tuple. Tuples cannot change size once created.
• Record - A collection of named values grouped together. Each value has its own name and type. Records are often used when storing information about people or places. Record elements are accessed by their names.
• List - An ordered collection of items enclosed by square brackets, separated by commas. List elements are accessed by their positions in the list. Lists can grow or shrink as necessary.
• Utility


  − A program with one purpose/piece of system software

  − …used for the upkeep/maintenance of the system
• Application


  -Application performs tasks for the user (rather than the computer).

  − Performs generic (rather than specific) tasks
• Extreme Programming (XP)


  A software development method that combines iteration, customer involvement, pair programming, and collective ownership.
• Server


  A device which provides a central point of control/access
• ACID in computing


  "A" refers to Atomic

  "C" refers to Consistency

  "I" refers to Isolation

  "D" refers to Durability
• ASCII vs Unicode


  Advantage − More characters can be represented − may include foreign alphabets − may include emojis Disadvantage − Reviews take up more storage (4 times their previous storage size).