An operating system is basically the general contractor of the computer.
Basically every computer, smartphone and game console you can buy on the market has one thing in common: they all require an operating system (OS) to run applications and do basic tasks. When it comes to computers, the most popular options are Microsoft’s Windows and Apple’s MacOS. Google’s Chrome OS has also entered the market for cheaper school laptops. (There’s a free tool to update old Windows and Mac computers with a new ChromeOs Flex, thereby extending their computer lives.) On the more niche end, we also have Linux, which is open source and features a huge degree of user customization options. All of these operating systems are integral to making their devices run, but what does a computer look like when no OS is installed at all?
Before we get into that, let’s clarify exactly what the OS does. An operating system is basically the general contractor of the computer. While the programs are busy doing their one specialized thing — plumbing, electrical, carpentry — the operating system is overseeing them all, communicating what they need to the processor and providing a common language that they can all work with to stay on the same page.
There are a few other things your operating system does that you probably don’t think about. For instance, it’s the operating system (not just the hard drive) that’s going to decide how to manage memory. The operating system needs to delegate how much memory each process uses and make sure no memory overlaps. Also keep in mind that your home computer is most likely a single-user, multitasking operating system. That means you only have one processor, but it can run many programs at once.
But here’s the kicker: It can’t actually do that.
When you’re downloading files, working on a spreadsheet and listening to music, your computer just appears to be doing these things simultaneously. In reality, the computer is switching between processes at extremely high speeds — so high, you don’t notice it. While you’re under the illusion that your central processing unit (CPU and operating system have a hand in every pot, your programs are under the impression that they have complete control of the operating system at any given moment.
So really, your operating system is designed to let the CPU deal with one thing at a time. But because it’s a computer and not a harried secretary, it can multitask so fast that the user wouldn’t even know. With the adoption of multi-core CPUs, processors can now handle four, six or more tasks at the same time. However, the OS is still in charge of deciding which of these tasks get the highest priority.
Now that we know a few of the ways our operating system works for us, let’s get into what a computer without an operating system would look like.
What Does a Computer Without an OS Look Like?
If an operating system does all the things we know it does, it seems downright impossible for a computer to exist without one.
In reality, the earliest computers didn’t have operating systems; they were huge machines tasked with one program at a time. For that reason, they didn’t really need operating systems. In fact, the earliest computers required a user to physically connect and disconnect wires from a plug board to retrieve computations. But if you don’t have an operating system, can you make your computer do anything?
Yes. But you have a lot of work to do. Without an operating system using and enforcing a standard, systematic approach to running the computer, you’re put in the position of writing code (or programs) that must tell the computer exactly what to do. So, if you want to type up a document in a word processing program, you’d have to create from scratch code that tells your computer to respond to each character pressed on your keyboard. Then you’d have to write a code that told the computer how those responses must translate to a screen. You’d have to tell your computer how to draw the character you want. Think of every single option or possibility your word processing program has. You’d have to write code for every single one of those directly onto your hard drive.
In the absence of an OS, your PC will boot using a small piece of firmware known as the BIOS (Basic Input/Output System). The BIOS governs very simple features such as resetting the clock, voltage regulation or diagnosing system errors. Its most useful function is the ability to select an installed disk from which to boot the proper OS, so it’s not going to be able to handle complex tasks like word processing or web browsing.
Let’s go back to our general contractor analogy. If we’re building a house, we’ll want it to have certain features like plumbing, electrical work and windows. In a computer, we also want features like a program that creates documents, one that accesses the internet and one that stores our photos. Without an operating system, it’s not just that your "carpenter" doesn’t know where to hammer in nails to a beam to get the room you want; it’s also that you have to forge the hammers and you have to create the nails.
An operating system provides a uniform set of screws, lumber and any other material you need. It can go back and forth between rooms so fast you didn’t even know it left the one you were in.
And that’s really important, because here’s another thing: Remember how we were talking about the operating system only being able to concentrate on one thing at a time? Well, without one, your computer could run one program. Period. You could create a document. You could save it. You could print it. But you couldn’t look at that document and keep a clock running on your desktop. If you don’t have an operating system, you’re stuck doing one — and only one — process at a time.
Now That’s Interesting
The first viable home computer was known as the MITS Altair, released in 1975, but it came with no screen, keyboard or operating system. Seeing a need for software on the platform, Bill Gates and Paul Allen founded Microsoft to build an OS for MITS. However, they only found real success after adapting software known as QDOS (Quick & Dirty Operating System) to the IBM PC in 1981. This operating system, rebranded as MS-DOS, would later serve as the basis for Windows.
Originally Published: Aug 29, 2012
Computer Operating System FAQ
What are the basic components of an operating system?
The three basic components of an operating system are file, process and memory management.
Why do computers needs an operating system?
An operating system is the most important software on your computer. It oversees all the programs and provides a common language so that they can work efficiently. It also manages the computer’s memory, processes, software and hardware.
Does every computer need an operating system?
While it seems impossible for a computer to exist without an operating system, the truth is the earliest computers didn’t have them. They were just big machines tasked with one program at a time. In contrast to this, modern day computers are required to perform many different tasks, often simultaneously, so without an operating system, your laptop wouldn’t actually work.
What are common operating systems?
The five most common operating systems are Lion (OS X 10.7), Mountain Lion (OS X 10.8), Mavericks (OS X 10.9), Yosemite (OS X 10.10) and El Capitan (OS X 10.11).
Lots More Information
- How Operating Systems Work
- How Web Operating Systems Work
- How BIOS Works
- Encyclopædia Britannica Online. "Chrome OS" (Dec. 4, 2022) https://www.britannica.com/topic/Chrome-OS
- Encyclopædia Britannica Online. "Operating system (OS)." 2012. (Aug. 16, 2012) http://www.britannica.com/EBchecked/topic/429897/operating-system-OS
- Encyclopædia Britannica Online. "Linux Operating System" (Dec. 4, 2022) https://www.britannica.com/technology/Linux
- Encyclopædia Britannica Online. "Mac OS" (Dec. 4, 2022) https://www.britannica.com/technology/Mac-OS
- Encyclopædia Britannica Online. "Microsoft Windows Operating System" (Dec. 4, 2022) https://www.britannica.com/technology/Microsoft-Windows
- Firesmith Donald. "Multicore Processing" Carnegie Mellon University. Aug. 21, 2017 (Dec. 4, 2022) https://insights.sei.cmu.edu/blog/multicore-processing/
- Linux Information Project. "Multitasking Definition." June 14, 2006. (Aug. 16, 2012) http://www.linfo.org/multitasking.html
- Microsoft TechNet. "Lesson 4 — Multitasking and Multiprocessing." Microsoft. 2012. (Aug. 16, 2012) http://technet.microsoft.com/en-us/library/cc767883.aspx
- Smithsonian. "Altair 8800 Microcomputer" (Dec. 4, 2022) https://americanhistory.si.edu/collections/search/object/nmah_334396
- Techopedia. "Altair Basic" June 14, 2016. (Dec. 4, 2022) https://www.techopedia.com/definition/31954/altair-basic
- Watkins, Thayer. "Nature and History of Operating Systems for Computers." San Jose State University Economics Department. (Aug. 16, 2012) https://web.archive.org/web/20120606133659/http://www.sjsu.edu/faculty/watkins/opsys.htm
- Whatsabyte. "Can You Use A Computer Without An Operating System?" (Dec. 21, 2022) https://whatsabyte.com/internet/computer-without-operating-system/
- White, Ron and Edward Downs. "How Computers Work." Que Publishing. November 2005. (Aug. 16, 2012) https://www.vitalsource.com/products/how-computers-work-ron-white-timothy-edward-v9780133096828
- WinWorld. "PC-DOS" (Dec. 4, 2022) https://winworldpc.com/product/pc-dos/1x
- WinWorld. "Windows 1.0" (Dec. 4, 2022) https://winworldpc.com/product/windows-10/101v
- WinWorld. "86-DOS" (Dec. 4, 2022) https://winworldpc.com/product/86-dos/100