Development of OS (PART 1)

• Prof. Oyelade Jelili, Mr. Henry Ogbu, Miss Nathaniel Jemimah, Mr. Okuoyo Otavie presented the lecture "Theoretical Advances in the Development of Operating System"
• The lecture outline includes: History of Operating System, Free OS, Free and Open source OS, GNU/Linux, BSD UNIX, Solaris, Benefits of Open Source Software, Operating System Services
• History of Operating System

  1. Modern computing (1950s) software came with source codes

  2. The original hackers (computer enthusiasts) at MIT's Tech Model Railroad Club left their programs in drawers for others to work on

  3. Homebrew user groups exchanged code during their meetings

  4. Company specific user groups, such as Digital Equipment Corporation's DECUS, accepted contributions of source-code programs, collected them onto tapes, and distributed the tapes to interested members

  5. In 1970, Digital's operating systems were distributed as source code with no restrictions or copyright notice

  6. Software companies sought to limit the use of their software to authorized computers and paying customers by releasing only the binary files compiled from the source code, rather than the source code itself, and protecting their code and their ideas from their competitors

  7. By 1980, proprietary software was the usual case
• History of Free OS

  1. Richard Stallman in 1984 developed a free, UNIX-compatible OS called GNU to oppose the proprietary use of software

  2. Free refers to freedom of use, not price

  3. The free-software movement holds that users are entitled to four certain freedoms: to freely run the program, to study and change the source code, to give or sell copies with change and without changes

  4. Stallman in 1985 formed the Free Software Foundation (FSF) with the goal of encouraging the use and development of free software

  5. The FSF uses the copyrights on its programs to implement copyleft, a form of licensing invented by Stallman

  6. Copylefting a work gives anyone that possesses a copy of the work the four essential software freedoms
• Free/libre software


  Software whose source code are readily available but licensed to allow no cost-use, redistribution, and modification
• Open-source software


  Software that can be modified, redistributed and commercialized, not necessarily licensed
• All free software is open source but not all open-source software is free
• GNU/Linux


  The most famous open-source operating system, with some distributions free and others open source only
• Microsoft Windows


  A well-known example of a closed-source software, proprietary software owned and restricted by Microsoft
• Apple's macOS


  A hybrid approach, containing an open-source kernel named Darwin but including proprietary, closed-source components as well
• GNU/Linux (Open source OS)


  1. In 1991, Linus Torvalds released a rudimentary UNIX-like kernel using the GNU compilers and tools and invited contributions worldwide

  2. Anyone interested could download the source code, modify it, and submit changes to Torvalds

  3. Releasing updates once a week allowed Linux operating system to grow rapidly, enhanced by several thousand programmers

  4. In 1991, Linux was not a free software, its license permitted only non-commercial redistribution

  5. In 1992, Torvalds rereleased Linux under the GPL, making it free software and open source

  6. GNU/Linux operating system kernel is called Linux (but the full operating system including GNU tools called GNU/Linux)

  7. Major distributions include Red Hat, SUSE, Fedora, Debian, Slackware, and Ubuntu
• GNU/Linux distributions


  • Red Hat Enterprise Linux
  • PCLinuxOS
  • PCLinuxOS Supergamer DVD
• Running Linux on a Windows (or other) system

  1. Download the free Virtualbox VMM tool and install it

  2. Choose to install an operating system from scratch, based on an installation image like a CD, or choose pre-built operating-system images that can be installed and run more quickly from a site like virtualboxes.org/images/

  3. These images are preinstalled with operating systems and applications and include many flavors of GNU/Linux

  4. Boot the virtual machine within Virtualbox
• BSD UNIX (Open Source)


  1. Started in 1978 as a derivative of AT&T's UNIX from the University of California at Berkeley (UCB) in source code and binary form

  2. It was not open source till 1994 because a license from AT&T was required

  3. BSD UNIX's development was slowed by a lawsuit by AT&T

  4. A fully functional, open-source version, 4.4BSD-lite, was released in 1994

  5. BSD UNIX exists in various distribution like FreeBSD, NetBSD, OpenBSD, and DragonflyBSD

  6. The source code is contained and controlled by a version control system (subversion)

  7. Version control systems allow a user to pull an entire source code tree to his computer and push any changes back into the repository for others to then pull
• Solaris


  The commercial UNIX-based operating system of Sun Microsystems, originally based on BSD UNIX but later moved to AT&T's System V UNIX as its base in 1991, open-sourced most of the Solaris code as the OpenSolaris project in 2005
• Benefits of Open Source software

  • Community support
  • Security
  • Revenue generation
  • Learning tools
• Operating System Services


  • User services
  • System services
• User services


  • User interface (UI)
  • Program execution
  • I/O operations
  • File-system manipulation
  • Communications
  • Error detection
• System services


  • Resource allocation
  • Logging
  • Protection and security
• Shells to be explained

  • Borne- Again Shell
  • Korn Shell
  • C Shell
• UNIX command to delete a file named StudentScore.txt on a BASH shell
• References: Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne (2018). Operating Systems Concepts, 10 Edition, John Wiley & Sons Inc; William Stallings (2005), Operating Systems, Internals & Design principles, fifth edition, Pearson Hall.