An operating system is software that
manages computer, hardware and
software resources and provides
common services for computer programs.
How it works?
An OS manages the hardware
and software resources of the
system. It provides a stable,
consistent way for applications to
deal with the hardware withou
having to know all the details
managing the hardware and
software resources , is very
important as various programs
and input/output methods to
work fine and get the complete
attention of the CPU.
Types of OS.
·single-tasking: only runs one program at a time.
·Multi-tasking: runs more than one program at a time.
·Single-user: have no facilities to distinguish users but
may allow multiple programs to run in tandem.
·Multi-user: extends the basic concept of multitasking
with facilities that identify processes and resources
such as disk space that allows multiple users to
interact with the system. ·Distributed: manages a
group of distinct computers and makes them appear
to be a single computer. ·Templated: refers to creating
a single virtual machine image as a guest OS.
·Embedded OS: are designed to be used in embedded
computers. They are designed to operate on small
machines like PDAs. ·Real-time: guarantees to process
events or data within a certain short amount of time.
·Library: a library OS is one ehich the services that a
typical OS provides such as networking, are provided
from the libraries.
OS developement is one of the most complicated
activities in which a computing hobbysit may engage. In
some cases, hobby developement is in support of a
homebrew computing device, for example, a simple
single-board computer powered by a 6502
microprocessor. Or, developement may be for an
architecture already in widespread use. OS
developement may come from entirely new concepts, or
may commence by modeling an existing OS.