System Architecture

System Architecture

1. Primary Storage

   • RAM
     • VOLATILE
       • WIPES when POWER LOST
     • TEMPORARY DATA from RUNNING apps
     • READ & WRITE
     • Virtual Memory
       • RAM FULL
       • On HARD DRIVE
       • MOVES Data from RAM
   • ROM
     • BOOT UP Instructions
     • NON-VOLATILE
     • READ Only
   • Flash Memory
     • NON VOLATILE RAM

2. Secondary Storage

   • Non-Volatile
   • Stores DATA and FILES
   • Storage Technologies
     • Magnetic
       • Example: HDD - Cheap, slow read/write, high capacity(Approx 2TB+), not durable
     • Solid State
       • Example: SSD - Expensive, Fast Read/Write, Durable(No moving parts), medium capacity(approx. 1TB)
       • Example: USB- Cheap, Fast Read/Write, Durable(No moving parts), Lightweight/Portable
     • Optical
       • Example: CD - Cheap, Portable/Lightweight, Not Durable, Approx 500MB

3. CPU

   • Fetch, Decode, Execute INSTRUCTIONS
     • ALU
       • CALCULATIONS
     • CONTROL UNIT
       • FLOW of DATA
   • CLOCK SPEED
     • CYCLES per SECOND
   • CACHE
     • FREQUENTLY used INSTRUCTIONS
     • QUICK to ACCESS
   • CORES
     • SIMULTANEOUS cycles

4. Von Neumann Architecture

   • LOGICAL Structure
     • BUS- CARRIES DATA
   • DATA & INSTRUCTIONS stored in SAME PLACE
   • Registers
     • ACCUMULATOR
       • RESULTS from ALU
     • MEMORY DATA REGISTER
       • DATA that is being FETCHED
     • MEMORY ADDRESS REGISTER
       • LOCATION of CURRENT INSTRUCTION
     • PROGRAM COUNTER
       • LOCATION of NEXT INSTRUCTION