von neumann machine

• His EDVAC (Electronic Discrete Variable Automatic Computer) is close to how computers are used

• four parts:

  • memory

    • where instructions and data are stored

  • control unit

    • interprets instructions while coordinating other units

  • arithmetic logic unit

    • performs arithmetic and logical operations

  • input/output

    • provides the interface with users

    • an accumulator interact with control unit and input/output

• Main feature is stored program

  • before all computers were built with fixed programs, much like today’s desktop calculators that cannot run other software

  • Stored program was a giant jump in making machine hardware be independent of software programs that can run on it.

  • A separation of hardware from software

• There is latency associated with data transfer between CPU and memory

  • To improve computing efficiency, today’s computers add more and more cache between CPU and main memory.

  • Caching at the chip level