You get to work and turn on your computer. You open up Microsoft Outlook to check your calendar and your email; Internet Explorer to access your company’s website; QuickBooks or other accounting software to manage your accounts; and Microsoft Word to finish the letter you started drafting yesterday. Did you know you are taking advantage of the underlying features of your operating system!?

Every computer, from the smallest notebook to the largest supercomputer, has an operating system (OS). The OS is critical; a computer cannot run without it. The operating system is the traffic cop of your PC, conducting the flow of “traffic” or data through the computer system by coordinating the hardware, software, processor, user interface, and the system’s memory. 

Did you know there are actually a number of different types of operating systems? Some operating systems co-ordinate resources for many users on a network (multi-user operating system), whereas other operating systems, such as those found in some household appliances and car engines, don’t require the intervention of any users at all (real-time operating system). Some OS’s are proprietary systems developed specifically for the devices they manage (single-user, single-task operating system), while others (the one your most familiar with, most likely) are available commercially, for personal and business use (single-user, multitask operating system). 

Let’s focus on the single-user, multitask OS, the most familiar to those of us who use the computer daily at work or home. This type of OS can handle only one person working on it at a time but can perform a variety of tasks. The most commonly used operating systems you hear about are Microsoft Windows, Windows XP, Windows Vista, or now Windows 7; or the Apple Macintosh operating system. The type of processor in the computer determines which operating system a particular desktop computer uses. The combination of operating system and processor is referred to as a computer’s platform.

Microsoft Windows and Macintosh operating systems are each designed to coordinate with a different series of processors. Windows OS’s are designed to coordinate with a series of processors from Intel Corp and Advanced Micro Devices, while Apple Macintosh operating systems worked primarily with processors from the Motorola Corporation, IBM, and Intel. The two operating systems are not interchangeable. If you attempt to load a Windows OS on a Mac, for example, the Mac processor would not understand the operating system and would not function properly.

The operating system manages the processor. When you use your computer, you usually ask it to perform several tasks at once, such as printing a word document, waiting for a file to download, and working on a power point presentation all at the same time. Although the processor is the powerful brains of the computer, processing all of it instructions and performing all of its calculations, it needs the operating system to arrange for the execution of all these activities in a systematic way to give the appearance that everything is happening simultaneously. To do so, the OS assigns a slice of its time to each activity requiring the processor’s attention. The OS must then switch between different processes thousands of times a second to make it appear that everything is happening seamlessly. Otherwise, you wouldn’t be able to print a document and open a web page at the same time without experiencing delays in the process. This ability to perform more than one task at a time is multi-tasking.

Also, when you utilize the many different devices for the computer system such as the keyboard, mouse, USB drive, and printer, it may appear that all these events work at the same time; in effect, the operating system switches back and forth between processes, controlling the timing of events the processor works on.

I have given you a brief summary of how the “traffic controller” of your PC, your operating system, manages the processor. Next month I will dig deeper into the “mind” of an operating system at ­user-interfaces as well as managing memory, hardware, and peripheral devices!