1. OPERATING SYSTEMS

2. What is operating system??
 An operating system (OS) is a collection of
software that manages computer
hardware resources and provides
common services for computer programs.
 The operating system is a vital component of
the system software in a computer system.
 Application programs usually require an
operating system to function.

4. History
 Early computers were built to perform a
series of single tasks, like a calculator.
Operating systems did not exist in their
modern and more complex forms until the
early 1960s.
 In the 1940s, the earliest electronic digital
systems had no operating systems. Electronic
systems of this time were programmed on
rows of mechanical switches or by jumper
wires on plug boards.

5.  In the early 1950s, a computer could execute
only one program at a time. Each user had
sole use of the computer for a limited period
of time and would arrive at a scheduled time
with program and data on punched paper
cards and/or punched tape.
 Later machines came with libraries
of programs, which would be linked to a
user's program to assist in operations such as
input and output and generating computer
code from human-readable symbolic code.

7. Mainframes
 Mainframe computers are computers used
primarily by corporate and governmental
organizations for critical applications, bulk
data processing such as census, industry and
consumer statistics, enterprise resource
planning, and transaction processing.

8.  The term originally referred to the large
cabinets that housed the central processing
unit and main memory of early computers.
 Later, the term was used to distinguish high-
end commercial machines from less powerful
units. Most large-scale computer system
architectures were established in the 1960s,
but continue to evolve.

9. Microcomputers
 The first microcomputers did not have the
capacity or need for the elaborate operating
systems that had been developed for
mainframes and minis; minimalistic operating
systems were developed, often loaded
from ROM and known as monitors.
 One notable early disk operating system
was CP/M, which was supported on many early
microcomputers and was closely imitated
by Microsoft's MS-DOS, which became wildly
popular as the operating system chosen for
the IBM PC.

10.  The introduction of the Intel 80386 CPU chip
with 32bit architecture
and paging capabilities, provided personal
computers with the ability to run
multitasking operating systems like those of
earlier minicomputers and mainframes.
 Steve Jobs, a co-founder of Apple Inc.,
started NeXT Computer Inc., which
developed the NEXTSTEP operating system.
NEXTSTEP would later be acquired by Apple
Inc. and used, along with code
from FreeBSD as the core of Mac OS X.

11.  The enormous investment in software for these
systems made since 1960s caused most of the
original computer manufacturers to continue to
develop compatible operating systems along
with the hardware. The notable supported
mainframe operating systems include:
 Burroughs MCP – B5000, 1961
to Unisys Clearpath/MCP, present.
 IBM OS/360 – IBM System/360, 1966 to
IBM z/OS, present.
 IBM CP-67 – IBM System/360, 1967 to IBM z/VM,
present.
 UNIVAC EXEC 8 – UNIVAC 1108, 1967, to OS
2200 Unisys Clearpath Dorado, present.

13. Examples of operating
systems
 UNIX and UNIX-like operating systems
 Unix was originally written in assembly
language. Ken Thompson wrote B, mainly
based on BCPL, based on his experience in
the MULTICS project. B was replaced by C,
and Unix, rewriten in C, developed into a
large, complex family of inter-related
operating systems which have been
influential in every modern operating system

15. Microsoft Windows
 Microsoft Windows is a family
of proprietary operating systems designed
by Microsoft Corporation and primarily
targeted to Intel architecture based
computers, with an estimated 88.9 percent
total usage share on Web connected
computers. The newest version is Windows
8 for workstations and Windows Server
2012 for servers. Windows 7 recently overtook
Windows XP as most used OS

17. OS X
 OS X , previously Mac OS X, is a series
of Unix-based graphical interface operating
systems developed, marketed, and sold
by Apple Inc. It is designed to run exclusively
on Mac computers, having been pre-loaded
on all Macs since 2002. It was the successor
to Mac OS 9, released in 1999, the final
release of the "classic" Mac OS, which had
been Apple's primary operating system since
1984.

19. Linux and GNU
 Linux (or GNU/Linux) is a Unix-like operating system
that was developed without any actual Unix code,
unlike BSD and its variants.
 Linux can be used on a wide range of devices from
supercomputers to wristwatches.
 The Linux kernel is released under an open source
license, so anyone can read and modify its code. It
has been modified to run on a large variety of
electronics.
 Although estimates suggest that Linux is used on
1.82% of all personal computers, it has been widely
adopted for use in servers and embedded systems[

21. Android(operating systems)
 Android is a Linux-based operating
system designed primarily
for touchscreen mobile devices such
as smartphones and tablet computers.
Initially developed by Android, Inc.,
whom Google financially backed and later
purchased in 2005.

22.  Android is open source and Google releases
the code under the Apache License. This open
source code and permissive licensing allows
the software to be freely modified and
distributed by device manufacturers, wireless
carriers and enthusiast developers.
Additionally, Android has a large community
of developers writing applications that
extend the functionality of devices, written
primarily in a customized version of the Java
programming language.

24. Apple iOS
 iOS (previously iPhone OS) is a mobile
operating system developed and distributed
by Apple Inc. Originally released in 2007 for
the iPhone and iPod Touch, it has been
extended to support other Apple devices such
as the iPad and Apple TV.

25.  The user interface of iOS is based on the
concept of direct manipulation, using multi-
touch gestures. Interface control elements
consist of sliders, switches, and buttons.
Interaction with the OS includes gestures
such as swipe, tap, pinch, and reverse pinch, all
of which have specific definitions within the
context of the iOS operating system and its
multi-touch interface.
 Internal accelerometers are used by some
applications to respond to shaking the
deviceor rotating it in three dimensions

27. The future of operating
systems.
 Operating systems have evolved through the
past years in a rapid manner.
 As the most important component in
computers, changes in the operating systems
have great consequences for users of computers.
 With the past changes in operating systems like
the giant rise from command-line interface to
the current graphical user interface, many
common tasks became easier for the computer
users.

28. Something Special……

29. Thank You….
 Done By
 MAHARAJA MUKHERJEE
 IX-A