Make your own free website on



Operating systems

Between the hardware and the application software lies the operating system. The operating system is a program that conducts the communication between the various pieces of hardware like the video card, sound card, printer, the motherboard and the applications.


Common Operating Systems

Originally the operating system was created by each company that manufactured a processor and motherboard. So each operating system was proprietary, that is, unique to each manufacturer. Problem: changing to a new computer meant your software had to be replaced! Not good marketing. So there was pressure early on to standardize things so that software could be transferred to the new (and of course better!) computer. This required more standardization in operating systems.


MS-DOS iconThe winner in the PC market was MS-DOS, Microsoft's Disk Operating System, and its twin at IBM, PC-DOS, also written by Microsoft. Now it's hard to recall those days when each computer had its own unique operating system. More on DOS Commands

Icon: Win95Windows 95 and Windows 98 are actual operating systems on their own. The previous versions of Windows use DOS as the operating system and adding a graphical user interface which will do multitasking. But with Windows 95 Microsoft released an operating system that can take advantage of the 32-bit processors.

Icon: Windows MeWindows Me (Windows Millennium Edition) is an upgrade of Windows 98, release date Sept. 14, 2000. The system resources required for this operating system are significantly higher than previous versions of Windows.

Icon: Windows NTWindows NT (the NT apparently came from New Technology) is an operating system for client-server type networks. The latest version of NT has a user interface that is practically identical to Windows 95. Since Windows NT is designed for the higher demands of networks, it has higher demands itself for disk space and memory.

Icon: Windows 2000Windows 2000 is an upgrade of Windows NT rather than of Windows 98.


Icon: WinXP

Windows XP is an upgrade to Windows 2000. It comes in two versions - Home and Professional. The Professional version contains all the features of the Home version plus more business features, like networking and security features. Microsoft: Which edition to choose

Icon: Windows CE Windows CE is for small devices like palmtop and handheld computers. Lite versions of a number of major applications are available to run on these devices. You can link your small computer to a regular one to synchronize documents and data.

Icon: Mac OS The Apple Macintosh is a multitasking operating system that was the first graphical interface to achieve commercial success. The Mac was an immediate success in the areas of graphics production, and still commands the lion's share of that market. Apple made a major marketing error when they decided to keep their hardware and software under tight control rather than licensing others to produce compatible devices and programs. While the Apple products were of high quality, they were always more expensive than comparable products that were compatible with Microsoft's DOS operating system. Apple's share of the computer market has dropped to an estimated 2.4% worldwide and 3.48% of the US market (MacWorld July 3, 2002). This is an example of how a near lock on a market can be lost in a twinkling. Mac Jaguar

Mac OS X, Version 10.2 (Jaguar) is the current version. Since January 2002, all new Mac computers use Mac OS X.

Icon: OS/2 Wrap IBM's 32-bit operating system is OS/2. This is a popular system for businesses with complex computer systems from IBM. It is powerful and has a nice graphical interface. Programs written for DOS and Windows can also run on this system. This system has never really caught on for PCs.

Icon: UnixUNIX is an operating system developed by Bell Labs to handle complex scientific applications. University networks are likely to use UNIX, as are Internet Service Providers. A lot of people have experience with UNIX from their college work. Many computer old-timers love UNIX and its command line interface. But all those commands are not easy to remember for newcomers. X-Windows is a graphical interface for UNIX that some think is even easier to work with than Windows 98.

Icon: LinuxLinux is an operating system similar to UNIX that is becoming more and more popular. (And it has the cutest logo!)
It is a open-source program created by Linus Torvalds at the University of Finland, starting in 1991. Open source means that the underlying computer code is freely available to everyone.  Programmers can work directly with the code and add features. They can sell their customized version of Linux, as long as the source code is still open to others. You can find more info at the Linux home site. 
By the way, the word Linux is generally pronounced with a short I and the accent on the first syllable, like LIH-nucks. Here is a link to an audio file of Linus Torvalds pronouncing it in English.

Now you are ready to proceed to the next lesson.