Fundamentals of Operating Systems: Types, Functions, and History

Definition of an Operating System (OS)

An Operating System (OS) is a program or set of computer programs designed to ensure the effective management of resources. It begins to work when you turn on the computer, managing the machine's hardware from the most basic levels, while also allowing essential user interaction.

Core Functions of Operating Systems

Operating systems perform several critical functions:

• Provide comfort and ease in using a computer.
• Efficiently manage computer resources and services running processes (programs).
• Provide a user interface for executing instructions (commands).
• Allow developmental changes in the OS itself to be made without interfering with services already provided (facilitating system evolution).

Key Features of an Operating System

OS features typically include:

• Managing user administration tasks.
• Resource Management (CPU, memory, I/O).

Types of Operating Systems

There are various classifications of operating systems, including:

• Multiprogramming Operating Systems (or Multitasking Operating Systems).
• Distributed Operating Systems.
• Network Operating Systems.

Multiprogramming and Multitasking Operating Systems

These systems are distinguished by their ability to handle the execution of two or more active jobs concurrently. They significantly improve system productivity and resource utilization.

Characteristics:

• Usually support multiple users (multiuser environments).
• Provide facilities to maintain the environment of individual users.
• Require user validation for security and safety.

Examples of operating systems that support multitasking include: UNIX, Windows 95, Windows 98, Windows NT, MAC-OS, and OS/2.

Distributed Operating Systems

A Distributed OS allows jobs, tasks, or processes to be distributed among a set of processors. This set of processors may reside in a single machine or across different machines, and this distribution is typically transparent to the user.

These systems are a collection of autonomous systems capable of communication and cooperation through interconnected hardware and software. Their key objective is transparency and generally providing means for the global sharing of resources.

Examples of existing distributed operating systems include: Sprite, Solaris-MC, Mach, Chorus, Spring, Amoeba, and Taos.

Network Operating Systems (NOS)

Network Operating Systems link two or more computers through a medium (physical or otherwise), with the primary objective of sharing different resources and system information.

The first network operating system focused on computers with a 68000 processor, later transitioning to Intel processors, such as Novell Netware.

The most widely used network operating systems include: Novell Netware, Personal Netware, LanManager, Windows NT Server, UNIX, and LANtastic.

Major Operating System Versions and Families

A historical look at major OS families and versions:

• Microsoft Windows Family:
  • MS-DOS (Microsoft Disk Operating System)
  • Microsoft Windows 1.0
  • Windows NT
  • Windows 95
  • Windows 98
  • Windows 2000
  • Windows ME
  • Windows XP
  • Windows Vista
  • Windows Mobile
• OS/2:
  • OS/2 2.0
  • OS/2 2.1
  • OS/2 3.0 and 4.0
• Linux
• Unix
• Macintosh Family:
  • Mac OS X
  • Mac OS X 10.0 "Cheetah"
  • Mac OS X 10.1 "Puma"
  • Mac OS X 10.2 "Jaguar"
  • Mac OS X 10.3 "Panther"
  • Mac OS X 10.4 "Tiger"
  • Mac OS X 10.5 "Leopard"