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1. Computer components

   • Processor
     • Central processing unit acts like the brain of the computer
     • Carries out instructions of stored programs on the computer
     • can fetch, decode, execute and writeback
     • Recieves input and provides the appropriate output
   • Motherboard
     • The main circuit board inside the computer
     • Connects the different parts of the computer together
     • Has slots for memory and expansion cards
   • Storage
     • Hard drive
       • A hard disk drive that is used to write a hard disk
       • Disadvantages
         • Take longer to access data than chips
         • Can crash and stop the computer from working
         • If the computer crashes a lot it can damage the disk leading to data loss
         • If the disk is inside the computer it cannot be easily moved to other computers
       • Advantages
         • Non-volatile so can permanently store and retrieve data
     • solid state drive
       • Non- volatile device
       • stores data using flash memory
       • It has no moving parts as the data is stored in microchips
       • Disadvantages
         • More expensive than hard drives
         • Limited storage capacity
         • Shorter lifespan than hard drives
     • Removable drive
       • Can be removed and inserted into other computers
       • Disadvantages
         • Can break easily
         • More likey to overheat
         • easily stolen
         • data isn't automatically backed up
       • Used to carry around data that can be saved or accessed by other computers
     • Cloud
       • Allows users to save their documents on the internet
       • Advantages
         • Automatically backs up documents
         • Can be accessed from any device
       • Disadvantages
         • Requires an internet connection
         • security can be an issue
         • You have to download apps
   • Memory
     • RAM
       • Volatile
       • quick at accessing data
     • ROM
       • Non-volatile
       • Used when the computer starts up
     • Cache
       • small memory next to the CPU
         • Can be accessed quickly
       • Temporarily holds instructions
       • Communication between CPU and RAM
   • Expansion cards
     • Sound Card: allows you to listen to sound through speakers
     • Network Card: prepares, sends and controls data on the netwrok
     • Graphics cards: produces the image on the monitor
     • Storage controller works as an interface between the motherboard and the other computer componets
     • A fiber channel works at high speeds and connects compute data storage to servers

2. computer systems

   • Embedded
     • A small comper system in a lager maechanical system
     • Benefits
       • It is low cost
       • Dedicated to one device
       • Uses little memory and microproccesors
     • Disadvantages
       • Difficult to upgrade
       • Trouble shooting is difficult
       • Hardware is limited
   • Mainframe
     • High performance computer used for large scale processing
     • Advantages
       • Can process data quickly and run at high speeds
       • Increased processing power
       • Very reliable
     • Disadvanatges
       • Need more space and security
       • Cost alot
       • Need training
   • Quantum
     • Uses quantum physics and qubits instead of bits
     • They make life more efficient

3. Connectivity methods

   • Copperwire
     • STP
       • Shielded from interference by a layer of metal
       • More expensive and more fradgile
       • carries data faster
       • Protected from interferance
     • UTP
       • Easily picks up interferance
       • Smaller and easier to work with
     • Use electricity to carry data so aren't very secure
   • Fiber cables
     • Use light to carry data
     • secure and don't pick up interference easily
     • High bandwidths
     • Resistant to electromagnetic interference
     • High installation costs
   • Wireless technologys
     • Bluetooth allows devices to connect over small ranges and transfer data
     • Wifi
       • Wireless network that provides access to the internet
       • Large range limited by walls and floors
     • GCM - 3G/4G a wireless mobile network that provides access as long as you have signal
     • Infrared, used in remotes
     • lasers send beams of light through the air, require a line of sight to work and can be affected by the weather
     • Microwave requires a line of sight to work. It needs two frequencies to allow two way communication, can be affected by the weather
     • Advantages
       • They have cheap set up costs
       • They can connect to multiple devices, without extra hardware
       • Can be moved with little distruption
     • Disadvantages
       • Interference can occur
       • The connection is not as stable as wired networks
       • Can be obstructed by walls or floors
       • Easier to hack

4. Communication Hardware

   • Hub
     • Centre of a computer network
     • connects computers in a network together allowing data to travel around the network
     • need little configuration as no proccessing is done at the hub
     • They have no filters so information is sent to all ports
   • Switches
     • Filters and forwards packets, but can't do much more
     • Reduces number of broadcast domains
     • They can use a CAM table for port to MAC mapping
     • Not good a limiting broadcasts
   • Wireless access point
     • A hardware device on a LAN that allows devices to connect using wifi and bluetooth
     • Provides network connectivity in public places
     • Users can move around freely and are able to share files with other devices connected to the network.
     • More users can access it
     • It can require extra cost and equipment to set up and can be difficult to do so
     • The connection can be obstrusted
   • Routers
     • Connects networks and acts as a dispacter within the network as it decides where to send the information
     • It is located at any gateway and is often included as part of a network switch
     • They choose the best path for the data to reach its destination, limiting collision
     • More expensive than a hub and uses lots of bandwidth to update
   • Modem
     • Provide access to the internet
     • Connecting a modem to a router means that any devices on the router can access the internet

5. Hardware trouble shooting

   • Event viewer
     • Allows you to monitor events in your computer system
     • Keeps logs on programs, security, and system events on your computers
     • You can use it to view any error messages
   • Self test
     • The power on self-test is the diagnostic testing sequence that a computers basic input/output system runs to determine if the computer keyboard, RAM, disk drives and other hardware are working correctly
     • The test is run when the power is turned on
     • If it has the necessary hardware and its working the computer begins to boot
   • BIOs diagnostics
     • Built in hardware monitoring features are used to collect information and monitor the hardware connected to the motherboard
     • Non-volatile
     • Used to perform hardware initialization
     • Uses beeps to communicate errors
   • IP configuration
     • IP addresses are needed in order for a device to connect to the internet
     • A DHCP sever is used to assign IP addresses and ensure the same one isn't given out twice
       • The ping test is used to verify an IP's uniqueness