We all have our favorite operating system -- some of us will only pick from the tree of Apple, while others prefer the Windows seat. It's easy to assume that a computer without an operating system is as useful as a cup of coffee without the cup. But what does an operating system do, and can a computer still compute without it?
Let's tackle the first question before we get into the nitty-gritty of a system-less computer. 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 know it. While you're under the illusion that your 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.
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.
So, 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.
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.
Starting from scratch on a computer is not for amateurs. If you're a serious engineer/developer, it is conceivable to use a computer without a preinstalled operating system. But for those of us who use their computer to do such vital tasks as keeping a spreadsheet of their Christmas list or checking out the latest Ryan Gosling meme, it's probably not so necessary. And remember, an operating system-less computer is only good for one program. Probably worth it to pony up the money for an operating system.
- Encyclopædia Britannica Online. "Operating system (OS)." 2012. (Aug. 16, 2012) http://www.britannica.com/EBchecked/topic/429897/operating-system-OS
- Klosowski, Thorin. "Browse Like Bond: Use Any Computer Without Leaving a Trace with Tails." Lifehacker.com. (Aug. 16, 2012) http://lifehacker.com/5916551/browse-like-bond-use-any-computer-without-leaving-a-trace-with-tails
- 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
- Science Channel. "How does an operating system manage a computer's memory?" 2011. (Aug. 16, 2012) http://curiosity.discovery.com/question/operating-system-manage-computer-memory
- Watkins, Thayer. "Nature and History of Operating Systems for Computers." San Jose State University Economics Department. (Aug. 16, 2012) http://www.sjsu.edu/faculty/watkins/opsys.htm
- White, Ron and Edward Downs. "How Computers Work." Que Publishing. November 2005. (Aug. 16, 2012) http://my.safaribooksonline.com/0789734249/part01?portal=oreilly#X2ludGVybmFsX0ZsYXNoUmVhZGVyP3htbGlkPTA3ODk3MzQyNDkvY2gwMw==