Computer systems

Computer systems

1. Hardware

   • parts of a computer you can physical touch
   • Input
     • Keyboard
     • Mouse
   • Output
     • Monitor
     • Speaker

2. Software

   • programs / applications within a computer
   • eg. Microsoft Word, Google Chrome

3. CPU

   • CPU carries out all of the processing for the computer system by following all the instructions give
   • Harvard
   • Von Nuemann
   • made from billions of transistors (electronic switches)
   • clock speed is the number of cycles per second (Hz)
   • processes data and instructions using the fetch - decode - execute cycle
   • Increasing amount of cores will increase the amount of instructions it can process per second

4. General-purpose computer

   • can be used for any general use and you can do whatever you want to

5. Dedicated systems

   • Has a fixed purpose so its designed for a particular purpose

6. Control systems

   • Designed to control machinery

7. Embedded system

   • A computer system that forms part of an electronic device
   • eg. washing machine, air conditioning, televisions, telephones
   • Advantages: low-power devices can operate effectively from a small power source, small in size to fit inside a wrist-torn device such as a fitness braclet

8. CPU has two main sections

   • Control unit
     • works with the CPU to control the flow of data within the system and to decode instructions
     • responsible for decoding the instructions and sending out the signals to control how data moves around the parts of the CPU
   • Arithmetic and logic unit (ALU)
     • performs all the arithmetic and logical operations within the CPU
     • carries out the calculations and logical decisions required by the program

9. Buses

   • A part of the computer architecture that transfers data and signals between the components of the computer
   • Data bus - carries data between the CPU amd memory
     • Bi-directional (two way)
   • Control bus - carries control signals around the CPU and memory
   • Address bus - carries memory addresses for locations to read from or written to
     • Uni-directional