Hardware

• Embedded systems


  Computer system which is built into another device to support its operation. The software written for an embedded system is called firmware.

  E.g.

  • Washing machines
  • Digital cameras
  • Sat-Navs
• Buses

  Buses allow data to be transferred to different parts of the computer.

  1. Address bus. When data is saved or loaded from memory, the address at which it is to be stored or loaded from must be sent.
  2. Data bus. Data will then need to be moved between several parts of a computer.
  3. Control bus. The controller uses the control bus to send control signals to different parts of the computer.
• The fetch-decode-execute cycle

  1. The fetch cycle takes the address required from memory, stores it in the current instruction register.
  2. CPU decodes it, which means it determines what operation needs to be performed based on the instruction's binary code.
  3. CPU performs the actual operation or computation specified by the instruction.
• RISC and CISC processors

  Reduced Instruction Set Computer (RISC)

  Complex Instruction Set Computer (CISC)
• RISC processor


  Can process a limit number of simple instructions. Complex instructions is broken down into a longer list of simpler instructions. Advantage is that RISC can break down simple instructions quicker. Less power consumption is used. Used in phones
• CISC processor


  Can process a large number of complex instructions. Advantage is that CISC doesn't have to break down complex instructions into a large list of simpler instructions. More power consumption. Used in computers
• Input and Output

  Input devices - An input device allows data, such as text, images, video or sound, to be entered into a computer system.

  Output devices - There are many outputs created by a computer system. These include printed documents, on-screen data and sound
• Motherboard


  The motherboard is the main circuit board of a computer.
• Graphics Processing Unit (GPU)


  A GPU is a microprocessor that performs the calculations needed to produce graphic images on screen.
• Integrated GPU


  An integrated GPU uses the computer’s RAM. An integrated unit is cheaper than installing a dedicated GPU. It generates less heat and uses less power. Good for watching videos
• Dedicated GPU


  A dedicated GPU has its own video memory. Dedicated cards provide the best visual experience. They use more power and need a good cooling system. Good for gamers
• Sound cards


  Sound cards convert analogue input signals into digital data and reverse this process for audio output.
• Routing


  Routing is the name given to the method of selecting paths along which packets are sent on a computer network. Specialist computer systems such as routers, switches, bridges, firewalls and ports construct a routing table in their memory.
• IP (Internet protocol) addresses


  An IP address is an address which is allocated to a computer system on a network, usually by a DHCP (Dynamic Host Configuration Protocol) server.

  An example of an IP address is 195.10.213.120.

  It is used to uniquely identify computer systems on a network, thus allowing communication between them.
• Internet Domain Name System (DNS) 


  A Domain Name System (DNS) is a distributed database that matches IP addresses to computer system resources.