Architecture of a Computer System

 Architecture of a Computer System

The computer system architecture is broadly divided into the following core components:

1. Input Unit

• Accepts data and instructions from external sources (e.g., keyboard, mouse, scanner).

• Converts input into a form understandable by the computer.

2. Central Processing Unit (CPU)

Also called the “brain” of the computer, it controls all operations. It includes:

• Arithmetic Logic Unit (ALU):

  • Performs all arithmetic and logical operations.

• Control Unit (CU):

  • Directs the flow of data and instructions within the system.

  • Coordinates between the CPU, memory, and I/O devices.

• Registers:

  • Small, fast memory units inside the CPU used for temporary storage.

3. Memory Unit

Stores data and instructions. It includes:

• Primary Memory:

  • RAM (Random Access Memory): Temporary and volatile memory.

  • ROM (Read Only Memory): Permanent and non-volatile memory.

• Secondary Memory:

  • Hard drives, SSDs, USBs – used for long-term storage.

4. Output Unit

• Converts processed data from the CPU into human-readable form (e.g., monitor, printer).

5. System Bus

• Connects all components and allows communication.

  • Data Bus: Carries actual data.

  • Address Bus: Carries memory addresses.

  • Control Bus: Carries control signals.

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Diagram Overview (Text Form)

[Input Unit] --> [CPU] <--> [Memory Unit]
                   |
              [Control Unit]
                   |
        [ALU] --- [Registers]
                   |
             [Output Unit]