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Paper 1 revision - Coggle Diagram

- - - - cores: a processor within a processor. More cores = more instructions that can be processed
      - Clock speed = how fast the cpu can work to perform one instruction
  - - - SCSI - Small Computer System Interface
      - SAS - Serial Attached SCSI
        
        Used in powerful computers - like servers
      - SATA - Serial AT attachment
        
        Used in most desktop computers.
        
        Less expensive, less high performing
        
        Allows data transfer between storage devices
      - Ports - an interface between a computer and another device
        
        data and power is transferred through ports
      - USB - universal serial bus
        
        both data and power can be transferred
        
        widely used and standardized
      - firewire
        
        Apples version of USB
        
        more expensive, but allows peer to peer communication
      - Network ports
        
        ethernet
        
        connects to wired network hardware
        
        Fibre Channel
        
        connects fibre optic cables
        
        slots into the computer, allows you to use fibre optic cables
        
        often used to connect servers to storage
  - - - Random Access Memory
        
        all data takes the same amount of time to be accessed
      - Holds Data and instructions temporarily (due to being volatile)
      - When a program or file is opened it is copied from the storage into RAM.
      - Typically between 4 - 32 GB in size
    - - Read Only Memory
        
        You are unable to change contents viewed in ROM
      - Stores instructions from BIOS and other essential programs.
      - Has a very small capacity - 5 - 10 MB
    - - Very small and very fast
      - Holds frequently accessed instructions and data
      - CPU cache is checked BEFORE ram -> cache is faster
      - cache sizes range from KB - MB
- - - - usually free
      - the program can be adapted or modified to fit your own purpose
      - communities may have already improved the code
    - - Vulnerabilities are out in the open
      - code can be exploited
      - code may not be fully vetted / adapted or checked.
      - support may not be available
- - - - Processes sound inputted/ outputted to and from the computer
      - CPU can delegate processing to the soundcard
- - - - more stable, more reliable
      - harder to intercept data
      - can have a longer range than wireless
    - - not very flexible - harder to add new devices or change arrangement
      - wires can take up space and be a hazard
  - - - needs a wireless router
    - - i.e, phone + wireless headphones
        
        ad hoc network - doesnt need extensive setups
    - - high bandwidth, affected by the weather
    - - uses light not visible to the human eye
      - used for short range networks -i.e remote controls
    - - like fibre optic but without a wire
      - high bandwidth but affected by the weather
    - - relays messages between two points on earth
    - - 4G, 5G
- - - - HDD - Uses magnetic disks that spin
        
        Cheaper per GB, generally reliable
        
        tend to fail after a few years
        
        not durable as they contain moving parts - also not portable
    - - Uses electronic circuits to store data
      - More expensive
      - Have higher read/write speeds
      - More durable
      - Uses flash memory technology
    - - When files are accessed via the internet - Held in an offsite location
      - Easily scaleable
      - Can be accessed from anywhere (if you have an internet connection)
      - Clients are reliant on the businesses security and for them to keep your data online.
- - - - potential fix - ensuring cables are plugged into expansion card, not mother board
    - - investigation - use POST for diagnostics (power on self test)
        
        potential fix - replace broken component
    - - potential investigation - look up the error code / online documentation
    - - happens when lots of programs are running
        
        increase RAM capacity
    - - can be caused by harddrive issues
        
        run a defragmentation tool on the harddrive.