Computer Architecture

Most modern computers are based on the Von Neumann Architecture.

The Von Neumann Model

The key idea: Data and Programs are stored in the same memory.

[Image of Von Neumann Architecture diagram]

Key Components

1. CPU (Central Processing Unit): The "brain."
   • ALU (Arithmetic Logic Unit): Does the math ($+ - * /$) and logic (AND, OR).
   • CU (Control Unit): Directs the flow of data.
   • Registers: Tiny, super-fast storage inside the CPU (e.g., Accumulator, PC).
2. Memory (RAM): Temporary storage for currently running programs.
3. I/O (Input/Output): Keyboard, Mouse, Screen.

The F-D-E Cycle

The heartbeat of the computer. It happens billions of times per second.

1. Fetch: The CPU retrieves the next instruction from RAM.
2. Decode: The CU figures out what the instruction means.
3. Execute: The instruction is carried out (e.g., "Add 5 to Register A").