The Evolution of Computing đź’»đź§
Operating systems (OS) are the silent conductors of the digital orchestra — managing hardware, enabling software, and shaping how humans interact with machines. This article offers insight into their history: what operating systems are, what they do, and why there are so many different types. From the earliest machines to the systems we use today, we’ll explore how OS design evolved alongside computing itself — setting the stage for the first part of our journey through the history of operating systems.
This article is part of the Operating Systems Series — where we explore how OS power and shape the world of computing. If you’d like to know what operating systems are and why they matter, check out the main article: 👉 — Operating Systems: The Hidden Power
The Pre-OS Era: Before Operating Systems Existed 🏗️
Long before modern operating systems were born, computers were massive machines that had to be operated entirely by hand. One of the first and most famous of these early computers was ENIAC, short for Electronic Numerical Integrator and Computer.
In 1946, the U.S. government, in partnership with the University of Pennsylvania, announced the development of ENIAC. Like many technologies of its time, it was built mainly for military purposes — to help calculate artillery firing tables.
ENIAC is often considered the first general-purpose electronic computer. But it was nothing like the sleek laptops we use today — it was a giant. The machine contained 18,000 vacuum tubes, 70,000 resistors, and 10,000 capacitors. It stood 8 feet tall, was 3 feet thick, stretched 100 feet long, and weighed around 27 tons. It consumed so much electricity that it could cause a nearby city’s lights to dim when it was switched on!
Despite all that size, ENIAC could perform only about 5,000 operations per second — which was still an incredible achievement for its time.
However, hardware is useless without software, and ENIAC was no exception. There were no keyboards, no screens, and indeed no operating systems. To make it do anything, engineers had to rewire thousands of connections on a patch panel manually. Each program was written out by hand, then punched onto cards, which were fed into the computer. The output came out on more punch cards, which a separate IBM punch card reader then read to print the results.
Programming ENIAC was slow, complex, and extremely tedious. It could take a team of five technicians an entire week to set up a single program, test it, find errors, and fix them — to get the machine to produce the right results.
By 1949, things started to improve. Computers began to include memory, though it was minimal and used tubes filled with liquid to store data. Around the same time, inventors began developing the basic elements of programming languages, making coding a little easier.
Then, in 1952, an exciting idea emerged — the concept of reusable code. Instead of punching new cards for every single run, programmers could now use the same punch cards to run the same program multiple times. Around this period, the assembler was also introduced—a tool that allowed programmers to write commands in a simpler, higher-level language that the computer could automatically translate into machine code (the language computers understand).
These breakthroughs laid the foundation for something revolutionary — the Operating System, which would soon take over many of these manual, repetitive tasks and make computing much more efficient and user-friendly.
The Early Days: The Dawn of Software and Early Operating Systems 🧮
By the mid-1950s, computers were slowly becoming more powerful and slightly easier to program. In 1954, a group of engineers at IBM made a breakthrough that would change the future of computing — they developed a programming language called FORTRAN, short for Formula Translation.
FORTRAN was revolutionary because it allowed programmers to write simple commands that the computer could translate into assembly language — the low-level instructions computers actually understand. This meant that instead of manually wiring circuits or punching thousands of cards for every operation, programmers could now tell the machine what to do in a more human-like way.
This new language saved an enormous amount of time. Tasks that once took days or weeks could now be completed in just a few hours. Soon, programmers began combining multiple FORTRAN programs together and sharing their code with others. This collaboration gave rise to an exciting new idea — a stable, consistent system to manage how programs interact with the computer’s hardware.
During the 1950s and 1960s, companies like IBM, Bell Labs, and several universities started experimenting with this idea. They wrote collections of code to handle routine tasks — such as loading programs, managing memory, and controlling input and output devices. Each of these code collections was explicitly made for a particular computer model, and together, they became known as the first operating systems.
These early operating systems were simple by today’s standards, but they marked the beginning of a new era. For the first time, computers could be told how to run programs — not just what to compute.
Standardization: The Birth of UNIX and the Push for Compatibility ⚙️
As computers became more common in the 1960s, one big problem became clear: operating systems were slow and incompatible with one another. Each company and university built its own OS that only worked on specific machines, which made it nearly impossible to share software or programs between systems.
That began to change in 1969, when a group of engineers at Bell Labs (a research division of AT&T) created something new — an operating system called UNIX. By 1973, they released the fourth edition of UNIX, which brought significant improvements and quickly made it stand out from everything else at the time:
- It was written in a new programming language called C, which was much easier to use and more flexible than FORTRAN.
- It could run on different types of hardware, meaning it wasn’t tied to just one computer model.
- It was faster and more efficient than any other operating system available.
By 1975, UNIX had spread to many universities, and its popularity skyrocketed as researchers and students began experimenting with it.
One of the most important moments in computing history came from a unique situation: Bell Labs was owned by the Bell System, the company that also controlled almost all telephone infrastructure in the United States. Because the Bell System was a regulated monopoly, it wasn’t allowed to enter the commercial computer business.
That meant they couldn’t sell UNIX for profit — so instead, they distributed it for free to universities and researchers. Even better, they allowed users to modify and improve the code as they wished. This effectively made UNIX one of the first open-source operating systems in history.
Throughout the late 1970s and early 1980s, most operating systems were still quite basic. They typically included a command-line interface (a place where users typed commands), the ability to load programs, and some basic device drivers to communicate with hardware.
Then came a major turning point — in 1981, IBM introduced its first personal computer (PC). With it came a need for an easy-to-use operating system that everyday people could manage. The system IBM bundled with its new PCs was called MS-DOS, short for Microsoft Disk Operating System.
MS-DOS became the foundation of personal computing in the 1980s, marking the beginning of the home computer revolution and paving the way for the graphical interfaces and user-friendly systems that would soon follow.
Pretty Pictures and Modern Operating Systems 🖼️
In 1981, the company Xerox introduced something revolutionary — the Xerox Star Workstation. It featured the world’s first window-based GUI, short for Graphical User Interface. This system introduced many of the conventions we now take for granted, like windows, icons, folders, and even the mouse for navigation.
However, despite its innovation, the Star Workstation never became very popular. It was expensive, aimed at businesses, and ahead of its time — most people simply weren’t ready for it yet.
But one company saw its potential: Apple. Apple licensed the core ideas of Xerox’s interface, improved upon them, and in 1984 launched the legendary Macintosh computer. The Macintosh was the first truly successful computer with a graphical interface, and it completely changed the way people interacted with technology. For the first time, everyday users could point, click, and drag — instead of typing long lines of text commands.
Up until that point, computer users interacted entirely through the keyboard, typing instructions into what was called a console or command line. Everything on the screen was text-based — no images, icons, or windows. The arrival of graphical displays marked a huge turning point, and from then on, graphical user interfaces were here to stay.
Meanwhile, Microsoft was also working to bring graphical computing to the masses. It tried several times to release a graphical product, but none took off until 1990, with the launch of Windows 3.0. Although Windows 3.0 offered a full Graphical User Interface, it was still built on top of the widely used MS-DOS (Microsoft Disk Operating System).
Then, in 1991, another milestone appeared — Linux. Created by Linus Torvalds, Linux was a new kind of operating system based on the principles of UNIX. Like UNIX, it was open source, meaning anyone could view, modify, and improve the code freely. However, Linux wasn’t an exact copy — it was a fresh, community-driven reimagining of UNIX’s power and flexibility.
Today, almost every modern operating system — from Windows, macOS, and Linux, to Android and even iOS — can trace its roots back to either UNIX or the Xerox Star. These innovations laid the groundwork for the modern, visually rich, and user-friendly systems that shape our digital world today.