• Computer Architecture refers to those attributes of a system that have a direct impact on the logical execution of a Examples:
    • the instruction set
    • the number of bits used to represent various data types
    • I/O mechanisms
    • memory addressing techniques
  • Computer Organization refers to the operational units and their interconnections that realize the architectural specifications. Examples are things that are transparent to the programmer:
    • control signals
    • interfaces between computer and peripherals
    • the memory technology being used
  • So, for example, the fact that a multiply instruction is available is a computer architecture How that multiply is implemented is a computer organization issue.
  • Architecture is those attributes visible to the programmer
    • Instruction set, number of bits used for data representation, I/O mechanisms, addressing
    • g. Is there a multiply instruction?
  • Organization is how features are implemented
    • Control signals, interfaces, memory
    • g. Is there a hardware multiply unit or is it done by repeated addition?
  • All Intel x86 family share the same basic architecture
  • The IBM System/370 family share the same basic architecture
  • This gives code compatibility
    • At least backwards
  • Organization differs between different versions