Operating systems have been evolving through the years. In the 1950s, computers were limited to running one program at a time like a calculator, but later in the following decades, computers began to include more and more software programs, sometimes called libraries, that formed the basis for today’s operating systems.

The first Operating System was created by General Motors in 1956 to run a single IBM mainframe computer, its name was the IBM 704. IBM was the first computer manufacturer to develop operating systems and distribute them in its computers in the 1960s.

Following is the timeline about Operating System evaluation:

• Stanford Research Institute developed the oN-Line System (NLS) in the late 1960s, which was the first operating system that resembled the desktop operating system we use today.
• Microsoft bought QDOS (Quick and Dirty Operating System) in 1981 and branded it as Microsoft Operating System (MS-DOS). As of 1994, Microsoft had stopped supporting MS-DOS.
• Unix was developed in the mid-1960s by the Massachusetts Institute of Technology, AT&T Bell Labs, and General Electric as a joint effort. Initially it was named MULTICS, which stands for Multiplexed Operating and Computing System.
• FreeBSD is also a popular UNIX derivative, originating from the BSD project at Berkeley. All modern Macintosh computers run a modified version of FreeBSD (OS X).
• Windows 95 is a consumer-oriented graphical user interface-based operating system built on top of MS-DOS. It was released on August 24, 1995 by Microsoft as part of its Windows 9x family of operating systems.
• Solaris is a proprietary Unix operating system originally developed by Sun Microsystems in 1991. After the Sun acquisition by Oracle in 2010 it was renamed Oracle Solaris.

Operating System Generations

Operating systems have been evolving over the years. We can categorise this evaluation based on different generations which is briefed below:

0^th Generation (1940 – early 1950s)

The term 0^th generation is used to refer to the period of development of computing when Charles Babbage invented the Analytical Engine and later John Atanasoff created a computer in 1940. The hardware component technology of this period was electronic vacuum tubes. There was no Operating System available for this generation computer and computer programs were written in machine language. This computers in this generation were inefficient and dependent on the varying competencies of the individual programmer as operators.

First Generation (1951-1956)

The first generation marked the beginning of commercial computing including the introduction of Eckert and Mauchly’s UNIVAC I in early 1951, and a bit later, the IBM 701.

System operation was performed with the help of expert operators and without the benefit of an operating system for a time though programs began to be written in higher level, procedure-oriented languages, and thus the operator’s routine expanded. Later mono-programmed operating system was developed, which eliminated some of the human intervention in running job and provided programmers with a number of desirable functions. These systems still continued to operate under the control of a human operator who used to follow a number of steps to execute a program. Programming language like FORTRAN was developed by John W. Backus in 1956.

Second Generation (1956-1964)

The second generation of computer hardware was most notably characterised by transistors replacing vacuum tubes as the hardware component technology. The first operating system GMOS was developed by the IBM computer. GMOS was based on single stream batch processing system, because it collects all similar jobs in groups or batches and then submits the jobs to the operating system using a punch card to complete all jobs in a machine. Operating system is cleaned after completing one job and then continues to read and initiates the next job in punch card.

Researchers began to experiment with multiprogramming and multiprocessing in their computing services called the time-sharing system. A noteworthy example is the Compatible Time Sharing System (CTSS), developed at MIT during the early 1960s.

Third Generation (1964-1979)

The third generation officially began in April 1964 with IBM’s announcement of its System/360 family of computers. Hardware technology began to use integrated circuits (ICs) which yielded significant advantages in both speed and economy.

Operating system development continued with the introduction and widespread adoption of multiprogramming. The idea of taking fuller advantage of the computer’s data channel I/O capabilities continued to develop.

Another progress which leads to developing of personal computers in fourth generation is a new development of minicomputers with DEC PDP-1. The third generation was an exciting time, indeed, for the development of both computer hardware and the accompanying operating system.

Fourth Generation (1979 – Present)

The fourth generation is characterised by the appearance of the personal computer and the workstation. The component technology of the third generation, was replaced by very large scale integration (VLSI). Many Operating Systems which we are using today like Windows, Linux, MacOS etc developed in the fourth generation.

Operating System Types Yearwise Evolution

Operating Systems evolved over time from almost no OS to AI Powered one. Following list shows the evolution of Operating Systems over time with technological advancements.

• Batch Processing Systems − These systems were popular From 1940s to 1950s. The users of a batch operating system did not interact with the computer directly. Each user prepared his job on an off-line device like punch cards and submited it to the computer operator who then batched the similar jobs together to speed up processing and run as a group. The programmers left their programs with the operator and the operator then sorted the programs with similar requirements into batches. In such systems, CPU usage was very low and it was difficult to prioritize jobs over one another.

• Multiprogramming Systems − These operating systems emerged from 1950s to 1960s and revolutionalized the computer arena. Now a user could load multile programs into memory and each program could have specific memory allocated. While one program was waiting for I/O operation, CPU was alloted to second program.

• Time-Sharing Systems − Such Operating system can be categorized from 1960s to 1970s yearwise. Time-sharing or multitasking is a logical extension of multiprogramming. Processor”s time which is shared among multiple users simultaneously is termed as time-sharing. The operating system used CPU scheduling and multiprogramming to provide each user with a small portion of a time. Computer systems that were designed primarily as batch systems have been modified to time-sharing systems.

• GUI Based Systems − From 1970s to 1980s, GUI based Operating Systems became popular. These operating systems were more user friendly. In stead of typing commands, a user could click on graphical icons. Microsoft Windows is one of earlier popular GUI based operating system which still dominates the personal computer space.

• Networked Systems − As time advances, so as technologies. From 1980s to 1990s, network based system gained momentum. A Network Operating System runs on a server and provides the server the capability to manage data, users, groups, security, applications, and other networking functions. The primary purpose of the network operating system is to allow shared file and printer access among multiple computers in a network, typically a local area network (LAN), a private network or to other networks.

• Mobile Operating Systems − From Late 1990s to Early 2000s, Symbian, Java ME based OS were popular for mobile devices. Over the period of time, with the introduction of smart phones, need of more complex operation systems arised. That leads to development of Android and iOS mobile operating system which are getting more and more powerful and becoming feature rich till date.

• AI Powered − From 2010s to Present

  In today”s time, Artificial Intelligence is dominating every aspects of computers including Operating Systems. Siri, Google Assistant, Alexa and many other AI based assitant softwares which can even understand the voice commands and can perform any operation that a user needs to perform.