A computer system is made up of hardware and software working together to process data.
The CPU & F-D-E Cycle
The Central Processing Unit (CPU) is the "brain" of the computer. Key components:
- ALU: Performs calculations and logical operations.
- Control Unit (CU): Controls the flow of data inside the CPU.
- Registers: Tiny, super-fast memory for temporary storage of data and instructions.
The CPU carries out the Fetch-Decode-Execute (FDE) cycle:
- Fetch: Retrieve the next instruction and its data from memory.
- Decode: Interpret the instruction to determine required actions.
- Execute: Carry out the instruction.
Von Neumann Architecture
This standard design stores both instructions and data in the same memory unit, allowing simple and efficient processing.
CPU Performance
- Clock Speed: More cycles per second = faster processing.
- Cache Size: Small fast memory; larger cache = less slow memory access.
- Number of Cores: More cores = multiple tasks processed simultaneously.
Storage & Software
- Primary Storage: Fast memory accessible by CPU (e.g., RAM).
- Secondary Storage: Long-term non-volatile storage (e.g., SSD, HDD).
- Embedded Systems: Specialized computers in devices like TVs or appliances.
- System Software: OS manages hardware and software; utility software maintains system.