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Computer science paper 2 - Coggle Diagram

- - - - Application software is responsible for user benefit. This can include word processors , internet browsers and games.
    - - System software preforms the tasks needed to operate the hardware , and provides services for other software.
        
        This can include the OS
        
        This can include game engines.
        
        This can include utility programs.
        
        And more.
      - Peripheral management
        
        A peripheral is defined as any supplementary hardware.
        
        The OS uses device drivers which are programs that convert between proripheral signals and OS signals.
        
        A driver is an interface which hides the complexities of hardware.
  - - - Command line interface is a shell and a GUI uses icons and visual indicators. the command line is much more direct and compact.
  - - - Only one process can be executed at one time.
  - - - Virtual memory is apart of the Hard drive and acts as more memory.
- - - - A little abstracted,
        
        Assembaly
        
        Low level
        
        An assembler uses simple mnemonics.
        
        They are specific to the hardware.
      - Most abstracted
        
        Pseudocode and Python
        
        High level
        
        They are portable meaning they can be executed on different computers.
      - Least abstracted.
        
        Machine code
        
        Low level
        
        Machine code has the least abstraction meaning it communicates directly to the processor.
        
        Assembly code and other high level languages have to be converted inti machine code.
        
        Machine code is specific to the processor , meaning that it is not portable and only corresponds to its instruction sets.
  - - - All code needs to be translated into machine code.
      - Types
        
        Assembler
        
        Uses the processor's instructions to set convert the instructions to the machine code equivalent which is an object code file.
        
        It allows optimisation as you can call subprograms within one line.
        
        Judgement.
        
        Disadvantages
        
        Advantages
        
        Quick and small
        
        Does not use a lot of memory or space.
        
        Complier
        
        A compiler scans through the source code and then executes it as one,
        
        Error messages are shown only after scanning though the whole code.
        
        After translation , a compiler is no longer needed as it can be distributed without the source code.
        
        Interpreter
        
        Translates and executes a line of code sequentially
        
        Stops when it meets an error.
        
        When you ship the code , you need the interoter and the source ode.
        
        Slower than a compiler
        
        Source code can be viewed.
- - - - Cache stores copies of frequently used data.
      - Cache is much faster than ROM
      - Cache is physically closer to the processor.
      - It is checked before the RAM in the Fetch-execute cycle.
    - - Rom stands for Read Only Memory
      - ROM can only be read.
      - Used small in small amounts in computers to store essential computer programs like the boot strap.
      - Firm ware is stored on ROM which helps the hardware.
      - ROM is non volitile.
    - - Stand for random access memory because the data is stored randomly.
      - Ram is very quick
      - Its function is to load open programs and operating system data currently in use from slower secondary storage , so it can be directly accessed by the CPU.
      - Ram is volatile.