Computer Software Notes B chap 3

CPU

  • IBM introduced the world’s smallest CPU in 2018, comparable to x86 processors from the 1990s.

Computer System

  • Consists of hardware (physical parts) and software (data/instructions).
  • System software: Controls hardware, manages resources (e.g., Windows, macOS).
    • Written in low-level languages.
  • Application software: Performs specific tasks for users (e.g., Excel, Photoshop).
    • Written in high-level languages.

System Software

  • Types:
    • Operating system.
    • Utility program.
    • Driver program.

Operating System (OS)

  • Controls hardware, interacts with drivers and applications.
  • Functions:
    • User interface.
    • User management.
    • Multitasking.
  • Types based on users:
    • Single-user.
    • Multi-user.
  • Types based on purpose:
    • Desktop OS (e.g., Microsoft Windows).
    • Mobile OS (e.g., iOS).
    • Network OS (e.g., Linux).
  • Types based on user interface:
    • Graphical User Interface (GUI).
    • Command Line Interface (CLI).

Utility Program

  • Maintains computer systems and improves efficiency.
  • Examples:
    • System monitor (e.g., Task Manager).
    • Virus checker (Antivirus software).
    • Data compressor (e.g., 7zip).
    • Defragmentation software.
    • Backup software (e.g., Time Machine).
    • Uninstaller.

Driver Program

  • Controls peripheral devices by translating requests into machine-level commands.
  • Specific to OS and peripheral device.

Application Software

  • Types:
    • Productivity software.
    • Communication software.
    • Media development software.
    • Educational software.

Communication Software

  • Used to exchange information between users via a network.
  • Examples: Web browsers, email clients, messaging applications, web conferencing software, file sharing software.

Media Development Software

  • Used to create or edit multimedia files.
  • Examples: Image editing software, audio editing software, video editing software.

Modes of Operation

  • Batch processing: Data collected and processed at regular intervals. Good for using idling system resources.
  • Real-time processing: Data processed immediately upon receipt. Requires large computing power.
  • Parallel processing: Multiple processors share memory to perform tasks concurrently or divide tasks into portions for each processor.
  • Distributed processing: Multiple computers connected via a high-speed network. Offers high scalability and multitasking.
  • Virtualisation: Divides hardware into virtual portions to create virtual machines, allowing different OS or incompatible software to run.