Chapter 3
Computer Software
•
An
operating system
(OS) is the
master controller for all of the activities
that take place within a computer.
–
Microsoft Windows XP, Mac OS, Linux,
UNIX
•
The operating system also interacts
with application software, device
drivers and hardware to manage a
computer’s resources
Operating System Overview:
Why does an operating system
need to manage memory?
• When you want to run more than one program at a time, the OS has to divide up memory and set aside RAM for each program
• The OS must ensure that
instructions and data from one area of memory don’t “leak” into an area allocated to another
program
• If it fails, data can get corrupted,
programs can “crash” and your computer will display error
•
The OS acts as a filing clerk that stores
and retrieves files from your disks and
CDs
–
It remembers the names and locations of
all your files
–
It keeps track of empty spaces where new
files can be stored
•
To ensure that they function correctly
•
OS communicates with the device
driver software so that the data can
travel smoothly between the computer
and the peripheral device
•
OS controls peripherals to ensure input
and output proceeds in an orderly
fashion
Why does the operating system
get involved with peripheral
•
A
user interface
can be defined as the
combination of hardware and software
that helps people and computers
communicate with each other
•
Two types of user interfaces
–
Graphical user interface
(GUI) provides
a way to point and click a mouse to select
menu options and manipulate graphical
objects that are displayed on the screen
–
Command-line user interface
requires
users to type various memorized
commands to run programs and
accomplish tasks
• Stored on the hard disk on most computers
• The OS’s small bootstrap program resides on the Master Boot Record (MBR) and provides the
instructions to load the core parts into memory when system boots
– These core components are called the kernel, and
provides the most essential OS services, such as memory management and file access
• The kernel stays in memory all the time your computer is on
• Other parts of the OS, such as customization
•
Yes, typically through helpful tools
called
utilities
, which are used to
–
Launch programs
–
Manage files
–
Get help
–
Customize the user interface
–
Configures equipment
•
Microsoft Windows
– Installed on over 80% of the world’s PCs
– Since its introduction in 1985, it has evolved
through several versions, such as Windows 3.1, NT, 95, 98, Me, 2000 and XP
•
Mac OS
– Used with Macintosh computers, manufactured by Apple Computer. Inc.
– PC and Mac platforms are not compatible
• Platform refers to the combination of a computer’s
•
UNIX
– Developed in 1969
– Command-line interface
– Many versions became available for mainframes and microcomputers
•
Linux
– Developed in 1991 by Linus Torvald as a school project, based on UNIX
– Linux is free
– Popular OS for e-mail and Web servers
– Most Linux versions have a GUI interface
• Red Hat Linux, Caldera OpenLinux, Debian, SuSE
•
Developed several years before
windows, it still has a GUI interface
•
Both have windows, icons, menus and
pointers
•
First operating system that most people
have used
•
DOS
(Disk Operating System) was
developed by Microsoft
•
Is part of the operating system kernel of
Windows 3.1, 95, 98 and ME
– DOS is well hidden behind the Windows GUI
– Found in the MS-DOS Prompt in the Start menu
Why do I keep hearing about
“DOS Command-Line Interface”
Classic Course Labs
Found in your
Computer Concepts BookOnCD
What are the options for PDA
operating systems?
1. To run more than one program at a time, the OS must allocate specific areas of _______ for each program.
2. A _______ is the combination of hardware and software that helps people and computers
communicate.
3. The core part of an OS is called its _______.
4. List 3 popular operating systems: _______, _______, _______
5. Windows uses a _______ interface.
1. To run more than one program at a time, the OS must allocate specific areas of RAM for each program.
2. A user interface is the combination of hardware and software that helps people and computers communicate.
3. The core part of an OS is called its kernel .
4. List 3 popular operating systems: Windows ,
Mac OS , Linux
5. Windows uses a graphical user interface.
“Using the Windows Interface”
New Perspectives Labs
Found in your
Computer Concepts BookOnCD
