Operating Systems

• Operating system (OS)


  Software that manages and controls computer hardware, serving as an intermediary between software applications and hardware resources
• Operating system


  • Provides a unified interface for software to run efficiently and securely
  • Facilitates user interaction with the computer system
• Key components of an operating system

  • Kernel
  • File system
  • User interface
• Goals of operating systems

  • Make the computer system convenient to use
  • Use the computer hardware in an efficient manner
• Types of operating systems

  • Batch operating system
  • Time-sharing operating system
  • Single-user operating system
  • Distributed operating system
  • Network operating system
  • Real-time operating system
  • Handheld operating system
• Batch operating system


  • Jobs which are of similar type are grouped together and treated as a batch
• Batch operating system examples

  • IBM OS/360
  • UNIVAC EXEC 8
  • Burroughs MCP
• Time-sharing operating system


  • Multiple jobs can be executed on a system at the same time by sharing the CPU time among them
• Time-sharing operating system examples

  • Unix
  • Linux
  • Multics
• Time-sharing vs multiprogramming


  • Time-sharing: Objective is to minimize response time, designed to allow multiple users to share a computer's resources simultaneously
  • Multiprogrammed batch systems: Objective is to maximize processor use, designed to automatically execute and process a sequence of jobs or tasks without user intervention
• Single-user operating system


  • Developed and intended for use on a computer or similar machine that will only have a single user at any given time
• Single-user operating system examples


  • Microsoft Windows
  • MacOS
• Distributed operating system


  • A collection of several separate (individual) systems which communicate and cooperate with each other (using some software) in order to provide the users, access to various resources that the system maintains
• Distributed operating system examples

  • AIX
  • Solaris
  • Mach/OS
• Network operating system


  • Runs on a server and provides the capability to manage data, users, groups, security, applications, and other networking functions
• Network operating system examples

  • Microsoft Windows Server
  • CISCO Internetwork OS
• Real-time operating system (RTOS)


  • Serves real-time systems where the time interval required to process and respond to inputs is very small (response time)
• Types of RTOS


  • Hard real-time systems
  • Soft real-time systems
• Hard real-time RTOS


  • Meant for applications where time constraints are very strict and even the shortest possible delay is not acceptable
• Hard real-time RTOS examples

  • Airplane sensor and autopilot systems
  • Spacecraft and planetary rovers
• Soft real-time RTOS


  • Less restrictive, try to reach deadlines but do not fail if a deadline is missed
• Soft real-time RTOS examples

  • Audio and video systems
  • Weather monitoring systems
• Handheld operating system


  • Designed to run on machines that have lower speed processors and less memory
• OS Responsibilities

  • Receptionist
  • Security Officer
  • Traffic Officer
  • Dispatcher
  • Accountant/Bookkeeper
  • Manager/Resource Manager
• Single-User Operating System


  •This is the most common type of OS used on a home computer, as well as on computers in offices and other work environments.
• Two types of Single-User Operating System: single-tasking and multitasking.
• A computer system is composed of three (3) main components: the Hardware, the Software, and the Liveware
• Hardware


  The physical parts that play an integral role in computer systems. It serves as the physical medium used by the clients to send, receive, and store data
• Software


  The programs and applications installed in your computer. This component is divided into two, namely, the System Software and the Application Software
• System Software

  A software that provides platforms to other software. These are low-level programs that runs in the background by the operating system at a fundamental degree
• Application Software


  A software created or written to perform a variety of specific tasks for the user
• Application Software

  • Microsoft Office (Word, Excel, PowerPoint)
  • Browsers (Google Chrome, Mozilla Firefox)
  • Media Player
  • Auto CAD
• Liveware


  Also known as computer users. The user instructs the PC to execute on guidelines
• The modern general-purpose computer system is consists of one or more CPU(s) and a number of device controllers connected through a common bus that provides access to shared memory
• Main hardware components of a computer system

  • Input Devices
  • Output Devices
  • Processing Devices
  • Storage Devices
  • Communication Devices
• Input Devices


  Used for entering data in the computer
• Input Devices

  • Keyboard
  • Microphone
  • Gamepad Controllers
  • Scanner
• Output Devices


  Any device that puts out the information or data to the user or to another device
• Output Devices

  • Monitor
  • Speakers
  • Headphones
  • Printer
• Processing Devices


  The core parts of the computer assigned to process data