"Chapter Three "Operating Systems

Chapter Three
Operating Systems
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Operating Systems
An operating system or environment is a collection of programs designed
to control the computer’s interaction and communication with the user. The
operating system essentially performs two important functions on the
computer: it manages the input devices (keyboard and mouse), output devices
(monitor and printer), and storage devices (hard and floppy disk drives), and it
also manages the files stored on the computer and recognizes the file types to
complete tasks.
Every computer requires an operating system to function. A computer must
load the operating system into memory before it can load an application
program such as Word, Outlook Express, or PhotoShop.
Examples of operating systems include DOS, Windows, Unix, Linux, and the
Apple Operating System.
3-1 DOS
was the original operating system for the PC and stands for Disk
Operating System. There have been many versions of DOS since its original
release. The two most commonly known ones are:
MS-DOS This version was created by Microsoft and is the most commonly
used on IBM and clone computers.
PC-DOS This version was created by IBM and guaranteed to work with a
genuine IBM Personal Computer; however, it may not work perfectly with
some IBM compatible computers.
In the current market, it is rare to find a computer still using DOS as the
operating system due to the display, e.g., text characters only. As well, typing
commands in order to perform a task was based on one line commands that
were often hard to decipher, especially when errors occurred.
With the exception of a system using the Unix operating system, all other
computers use a graphical operating system like Windows or the Mac OS
(Operating System). This has become the standard for operating systems over
the last few years as they make working with computers much easier.
The graphical user interface (GUI ? pronounced “Gooey”) allows a person to
use a mouse and other devices to point and select desired functions rather than
having to remember commands. Many of these commands and functions
appear as buttons or have a picture/symbol to represent the task to be
accomplished. Software vendors also design their programs to use the same
buttons/symbols/pictures for commonly used functions (e.g., cut, copy, paste,
bold, save, print, etc.) which helps reduce the time to learn new software.
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3-2 Microsoft Windows
is the operating system for PCs. Windows products allow a
WYSIWYG (“What You See Is What You Get”) screen display, which is
especially important for word processing, desktop publishing, graphics design,
multimedia, or web development programs. Following is a brief history and
explanation of the evolution of Windows to the current version today:
1-Windows 3.x
This was the first version of Windows introduced. Before Windows
could be installed, DOS had to be installed and set up on the computer. This
version introduced the graphics user interface (GUI) that became widely
accepted by PC users on their desktop. As technology advanced, this version
became obsolete.