Week 4: Computer System Components (Updated & Expanded)

A computer system can be understood as a functional machine that transforms input data into meaningful output through processing and storage. From a mathematical and computational perspective, a computer system performs operations on sets of data using a controlled sequence of instructions.

A modern computer system consists of four primary functional components:

1. Input Devices (Data Acquisition)

Function: Input devices transmit raw data and control signals into the computer system for processing.

Examples:

• Keyboard (discrete symbol input)
• Mouse / Trackpad (positional input)
• Scanner (image‑to‑digital conversion)
• Webcam (visual data capture)
• Microphone (audio‑to‑signal conversion)
• Touchscreen (combined input + output)

2. Processing Device – CPU

Function: The CPU is the “brain” of the computer. It executes instructions from software by performing:

• Arithmetic operations (+, −, ×, ÷)
• Logical operations (AND, OR, NOT)
• Control operations
• I/O coordination

Mathematical View:

CPU: x → f(x) → y

3. Output Devices (Result Presentation)

Function: Output devices send processed data from the computer to the user or another system.

• Monitor
• Printer
• Speakers
• Projector

4. Storage Devices (Memory Systems)

A. Primary Storage (Volatile – RAM)

CPU ⇄ RAM (Fast, Temporary)

B. Secondary Storage (Non‑Volatile)

RAM → SSD/HDD → RAM

Summary Diagram