What is operating system
How it helps
Types of operating system
The very first OS and the progressive ones
Why it was developed (Need of OS)
How needs increased
Working Of OS (basic)
Applications and Uses
What is Operating System
• An operating system manages computer resources, such as memory
and input/output devices, and provides an interface through which
a human can interact with the computer
• An operating system allows an application program to interact with
these other system resources
An operating system
interacts with many
aspects of a computer
The Layers Of A
1: Operating Systems Overview
How it Helps
• The various roles of an operating system generally revolve around the
idea of “sharing nicely”
• An operating system manages resources, and these resources are
often shared in one way or another among programs that want to
o Multiprogramming which deals in keeping multiple programsin main
memory at the same time these programs compete access to the CPU
so that they can execute.
o Memory Management which keeps track of what program are in memory
and where in memory they reside.
How it Helps
• Hiding the complexities of hardware from the user
• Managing between the hardware's resources which include the
processors, memory, data storage and I/O devices
• Handling "interrupts" generated by the I/O controllers
• Sharing of I/O between many programs using the CPU
• And in some cases providing user interface to work easily.
Is There More Than One Type Of OS?
• Generally, there are four types, based on the type of computer they
control and the sort of applications they support.
This type manages the
computer so that one user can
effectively do one thing at a
Types Of Operating System
2. Multi-user, multi-task
Allows two or more users to run programs at the same
time. Some operating systems permit hundreds or even
thousands of concurrent users.
Types Of Operating System
3. Real Time Operating Systems
RTOS are used to control machinery,
scientific instruments, and industrial
There is typically very little userinterface capability.
Resources are managed so that a
particular operation executes
precisely the same every time.
Types Of Operating System
4. Single-user, Multi-tasking
This is the type of operating system most
desktops and laptops use today.
Microsoft’s Windows and Apple’s MacOS are both
examples of operating systems that will
let a single user have several same time Programs in
operation at the same time.
• There are few more enduring manifestations of user interface
technology than that of the Graphical User Interface Desktop.
Pioneered by engineers at Xerox PARC, refined by Steve Jobs and
Apple and brought to masses and ingrained into our daily lives by
Graphical User interface OS launched
• Apple company was the first
company which introduced the
graphical user interfaced
operating system as macintosh
• Microsoft which started a major
breakthrough by developing a
graphical user interfaced OS
known as Windows while
competing with apple
Windows 6 and 6.5
Windows 8 Mobile
MAC OS X Cheetah
MAC OS X Hera
MAC OS X Jaguar
MAC OS X Panther
MAC OS X Kodiak
MAC OS X Mini
Kit Kat (near future)
The very 1st Operating Sytem
The earliest computers were mainframes that lacked any form of operating system
EXEC was the very first operating system developed by UNIVAC who was
the first commercial computer manufacturer in 1970’s which was based on
Real Time basic to support large scale time sharing.
TOPS-10 and TOPS-20 was next few OS developed by Digital Equipment
Corporation which were time sharing systems for the 36-bit PDP-10 class
systems. Prior to the widespread use of UNIX, TOPS-10 was a particularly
popular system in universities, and in the early ARPANET community.
MS-DOS and UNIX were the major breakthrough in development of OS
which is said as written of Microsoft Corporation(Precisely) under IBM PC,
Intel 8088 CPU and Motorola 6899 CPU family.
Most famous Operating System
• UNIX is the most famous Operating System which is the current base
of the most working operating system now days.
• Basically UNIX was written in assembly language by Ken Thompson in
AT&T Bell laboratories and Unix rewritten in C, developed into a
large, complex family of inter-related operating systems which have
been influential in every modern operating system
• UNIX based OS are basically Servers, Workstation and Linux and BSD
based operating system.
The Process States of Operating System
• The Process States
Basic functions of the operating system
Controls peripheral devices connected to the computer
Transfers files between main memory and secondary
storage, manages file folders, allocates the secondary
storage space, and provides file protection and
Allocates the use of random access memory (RAM) to
Allows the computer to run other applications
Operating System Design and
• Design and Implementation of OS not “solvable”, but some
approaches have proven successful
• Internal structure of different Operating Systems can vary widely
• Start by defining goals and specifications
• Affected by choice of hardware, type of system
• User goals and System goals
• User goals – operating system should be convenient to use, easy to learn,
reliable, safe, and fast
• System goals – operating system should be easy to design, implement,
and maintain, as well as flexible, reliable, error-free, and efficient
• MS-DOS – written to provide the most functionality in the least space
• Not divided into modules
• Although MS-DOS has some structure, its interfaces and levels of
functionality are not well separated
Application And Uses
• Providing a proper base to run programs of different kind like
To develop new program with easy user interface.
• The main use of an operating system is to ensure that a computer can be
used and do exactly what the user wants it to do.
Future Operating Systems
• The operating system - the baseline operating system: a typical desktop Linux can be
quite resource hungry. However, properly specified Linux also has a proven track
record of offering services within a restricted resource environment such as on
mobile phones or media players.
• An opportunity for RISC OS?
• RISC OS has in it's favour:
• It can work in a low memory, slow CPU environment. Current versions of RISCOS can boot to a
desktop with less than 512k of RAM. Even this could be improved upon with customisation.
• It's designed to be ROM loadable with only a few disk based resources. RISC OS doesn't need to be
tied to a hard disk as it doesn't need a swap file or masses of disk based configuration. If the OS
is installed it ROM, it can even boot without a hard disk.
• Fast start up and shutdown. On most RO workstations, there is a 'shutdown procedure' but this is
mainly to flush any disc buffers. It's not a protracted sequence.
• It's modular: it's designed to have features added to its core and to be tailored to a specific task.
• For person with a desktop machine, the OS gives interface to
the machine that fills some gaps in his digital life. As such a
user can connect the hardware and can control to his existing
network through OS interface easily, it could occupy a
conceptual space similar to that of Apple's new iTV device but
somewhat more computer than dedicated media.
• Application of Operating System Concepts to Coordination in Pervasive Sensing and Computing
Systems by Jesse M. Davis, Joseph B. Evans Benjamin J. Ewy, Larry M. Sanders, 2006