Operating system

From WE Computers Museum
Operating system
Developer numerous
Publisher numerous
Platforms numerous, see operating systems
Released 1947-present
Added to
numerous, see operating systems

An operating system, or OS, is system software that manages hardware and software resources.

Early computers

In the 1940s, electronic digital computers lacked operating systems. Tasks were controlled by switches or by plugs on a plugboard.

Resident monitors

In the early 1950s, general-purpose computers were developed. These computers could run any task given to them, although they could only execute one program at a time.

Another program could not be executed until the task was completed or the computer crashed.

The program was managed by a resident monitor, the precursor of the operating system. The resident monitor was an extremely small program that was resident in the limited memory of the computer.

The resident monitor would control the computer before and after a job by executing non-resident programs for setup and cleanup procedures.

Computers with internal libraries of programs

Another precursor to the operating system came in the mid-1950s. Computers of this era contained libraries of programs.

A program was inserted on external media and one of the internal libraries would be called upon to help with the media inserted.

Examples of the tasks being assisted through the internal libraries include relaying information through input devices or compiling human-readable source code into computer-readable machine code.

The drawback of these internal libraries was that, like the earlier resident monitor, only one program could be executed at a time.


GM-NAA I/O was the first operating system. It was created in 1956 by Robert L. Patrick of General Motors Research and Owen Mock of North American Aviation for the IBM 704 computer.

It was based on the General Motors-developed resident monitor on the IBM 701.

GM-NAA I/O was designed for batch processing wherein a program would be automatically executed once another program was completed.

SHARE Operating System

The SHARE Operating System was the first operating system that referred to itself as such. It was created in 1958 by the SHARE user group as an improvement on the GM-NAA I/O operating system. As the name suggests, it was designed to improve the sharing of programs.

It was the operating system for the vacuum tube-based computer, the IBM 709, which was released in 1958. It was also ported to the transistor-based update of the 709, the IBM 7090, which was released in 1959.

Operating systems owned by WEC Museum

Title First release Date Added to the Museum Notes
Android 2008 August 7, 2015 Installed on the Samsung Galaxy Core Prime.
Chrome OS 2011 December 30, 2021 On the Lenovo Chromebook 3
FreeDOS 1998 October 31, 2019 FreeDOS is installed on DOSBox on the Mac Mini.
iOS 2007 May 30, 2014 Installed on the iPad and iPod Touch.
Linux 1991 June 7, 2014 Ubuntu is on a partition of the Mac Mini. A Linux kernel also runs the NES Classic Edition, the Famicom Mini, the Shonen Jump Famicom Mini, the SNES Classic Edition, the Super Famicom Mini, and Super Retro Cade.
macOS 2001 June 7, 2014 Sierra (10.4) is installed on the MacBook Air and Catalina (10.15) is on a partition of the Mac Mini.
MS-DOS 1980 February 6, 2021 WEC Museum owns MS-DOS 3.3 distributed by AGI Computer.
Windows 10 2015 July 15, 2015 It is installed on the Bootcamp partition on the Mac Mini.
Windows CE 1985 July 6, 2022 Windows CE 6.0 is installed on the SYNET7WID.
Windows NT 4 2016 May 15, 2020 WEC Museum owns Windows NT Workstation 4.0.