Unit 1.1 System Architecture

Unit 1.1 System Architecture

1. Volatile Memory (Primary Storage)

   • Processes Data
     • The “brains” of the computer Carries out instructions (Executes Instructions
     • 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
     • The address is transferred along the Address Bus to Main Memory (this address indicates which part of memory to fetch the data/instructions from

2. Carries Data/Instructions from Main Memory to the Processor (or from other secondary storage devices) to the processor. Bi-Directional (two way) Data can be read/written

   • These are used to allow an interface between a hardware device external to the motherboard (e.g. a Keyboard) and the Processor itself. I/O controllers are used for: Keyboard, Mouse, Disk Drive, VDU
     • There are 3 main types of
   • Fetch part of the cycle Program counter is incremented for each instruction of the program being executed The contents of the Program Counter are put into the MAR (Memory Address Register)

3. Softwere

4. cache

5. Register

6. BIOS