1.1-System Architecture

1.1-System Architecture

1. PROCESSOR

   • Has clock speed
     • number of cycles per second
     • measured in hertz
       • MHz-GHz
   • Brains of the computer system
   • Executes/carries out instructions
   • Has cores in which instructions are executed
     • Dual Core-Quad Core-8 Core

2. MAIN MEMORY

   • RAM-Random Access Memory
     • Holds data and instructions that are currently in use by the processor
     • Located on the motherboard
     • Directly accessible by the processor
     • All data/instructions are lost once power is turned off.
   • ROM-Read Only Memory
     • Instructions are permanently etched onto a ROM chip.
     • When power is turned off-instructions still remain on the ROM chip.
     • Bootstrap loader is held in ROM- gives the instructions to start up an operating system

3. SYSTEM BUSSES

   • A bus is set of parallel wires connecting two or more independent components of a computer system in order to pass signals between them.
   • The system is separated into 3 different busses
     • The data bus
       • The address bus
         • The control bus
           • Control signals are sent along the control bus
             • E.g. Memory Read, Memory Write
             • This instructs which data will be travelling to/from memory
         • Carries addresses from the processor to the main memory
         • It is one direction
         • The processor generates an address
         • All data/instructions are returned on the data bus
       • Carries data/instructions from the main memory to the processor.
       • Bi-Directional
       • Data can be read or written

4. SECONDARY STORAGE

   • Hard Disk Drive
   • Solid State Drive
   • Flash Memory
   • DVD-R
   • Blue-ray