Lecture Notes: Types and Components of Computer Systems

Overview

• Focus on Cambridge RDC ICT theory
• Key topics: Hardware, Software, Main components of computer systems, Operating systems, Types of computers, Emerging Technologies

Hardware vs. Software

Hardware

• Definition: Physical components of a computer, visible and tangible.
• Types of Hardware:
  • Internal Hardware: Inside the system unit, e.g., motherboard, CPU, RAM, video card.
  • External Hardware: Outside the system unit, e.g., monitor, keyboard, mouse, printer.
• Motherboard Analogy: City with buildings (CPU, RAM, etc.) contributing to overall function.

Software

• Definition: Coded instructions or programs controlling computer operations and processing data.
• Types of Software:
  • Application Software: Used for specific tasks, e.g., Microsoft Word, AutoCAD.
  • System Software: Operating systems and utilities (e.g., antivirus, disk cleaners).

Data Representation

• Analog Data: Physical data, smooth transitions, e.g., voice.
• Digital Data: Binary (1s and 0s), discrete transitions.
• Conversion: Analog to Digital Converter (ADC) and Digital to Analog Converter (DAC).
  • Analog input converted to digital by ADC, digital output converted back to analog by DAC.

Main Components of a Computer

• Central Processing Unit (CPU)

  • Brain of the computer.
  • Arithmetic and Logic Unit (ALU) for calculations and decisions.
  • Control Unit for input/output control.
  • Registers for temporary data storage.

• Memory

  • Random Access Memory (RAM): Temporary, volatile, read/write memory, size can be increased.
  • Read-Only Memory (ROM): Permanent, read-only, stores boot instructions (BIOS).

• Storage Devices

  • Hard Disk Drive (HDD) or Solid State Drive (SSD): Permanent storage of large data, application software, operating system files.

Input and Output Devices

• Input Devices: Hardware for entering data (e.g., keyboard, mouse).
• Output Devices: Hardware for displaying data (e.g., monitor, printer).
• Comparison:
  • Inputs are complicated to use; outputs are simple.
  • Inputs send data only; outputs receive data to generate output.

Internal vs. Backing Storage

• Internal Memory: RAM and ROM, fast access, directly accessible by CPU.
• Backing Storage: HDD/SSD, permanent, larger storage capacity, slower access times.

Summary

• Understanding the types and components of computer systems is crucial for ICT theory.
• Differences between hardware/software, analog/digital data, and various storage types are key concepts.

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