The document discusses various types and features of operating systems. It describes batch processing operating systems which process jobs in a first come first served manner without user interaction. Multiprogramming operating systems aim to reduce CPU idle time by allowing new jobs when the current job is waiting. Multitasking operating systems allow users to interact with programs while they run by rapidly switching between processes. Network, distributed, and multiprocessor operating systems are also outlined which respectively manage resources over a network, use loosely coupled interconnected computers, and employ multiple shared processors. Key features of operating systems like memory management and device drivers are also listed.

1. Features and Types of Operating
System
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2. Contents
 We will learn
1. Generic Components of Operating System
2. Features of Operating System
3. Types of Operating System

3. Operating system structure with shell and kernel
Operating System Generic Components

4. Features of Operating System
 Protected and supervisor mode
 File and Disk Management: Allows disk access and file
systems
 Keep track of Device drivers
 Networking Security
 Program Execution
 Memory management ,Virtual Memory, Multitasking
 Handling I/O operations
 Manipulation of the file system
 Error Detection and handling
 Resource allocation-CPU
 Information and Resource Protection

5. Operating System Functions
https://electricalfundablog.com/operating-system-os-functions-types-resource-
management/

6. Types of Operating System: Batch processing
• It is a technique in which an Operating System collects the programs
and data together in a batch before processing starts.
An operating system does the following activities related to batch
processing −
1. The OS defines a job which has predefined sequence of commands,
programs and data as a single unit.
2. The OS keeps a number a jobs in memory and executes them
without any manual information.
3. Jobs are processed in the order of submission, i.e., first come first
served fashion.
4. When a job completes its execution, its memory is released and the
output for the job gets copied into an output spool for later printing or
processing.

7. Types of Operating System
Advantages
• Batch processing takes much of the work of the operator to the computer.
• Managing large work repeatedly in batch systems becomes easy.

8. Types of Operating System
Disadvantages
• CPU is often idle, because the speed of the mechanical I/O devices is slower than the
CPU.
• Lack of interaction between the user and the job..
• Due to lack of protection scheme, one batch job can affect pending jobs.

9. • The operating system keeps several jobs in memory simultaneously.
• The goal is to reduce CPU idle time by allowing new jobs to take over
the CPU whenever the currently running job needed to wait (e.g. for
user I/O).
• It increases CPU utilization by organizing jobs (code and data) so that
the CPU always has one to execute.
Types of Operating System:
Multiprogramming

10. CPU time or CPU usage can be reported either for each thread, for each
process or for the entire system. Moreover, depending on what exactly
the CPU was doing, the reported values can be subdivided in:
• User time is the amount of time the CPU was busy executing code in
user space/mode.
• System time is the amount of time the CPU was busy executing code
in kernel space.
• Idle time (for the whole system only) is the amount of time the CPU
was not busy. Idle time actually measures unused CPU capacity.
CPU Time

11. Types of Operating System:
Multiprogramming
Advantages of multiprogramming are −
Increased CPU Utilization − Multiprogramming improves CPU utilization as it
organizes a number of jobs where CPU always has one to execute.
Increased Throughput − Throughput means total number of programs executed
over a fixed period of time. In multiprogramming, CPU does not wait for I/O for the
program it is executing, thus resulting in an increased throughput.
Shorter Turn around Time − Turnaround time for short jobs is improved greatly in
multiprogramming.
Improved Memory Utilization − In multiprogramming, more than one program
resides in main memory. Thus memory is optimally utilized.
Increased Resources Utilization − In multiprogramming, multiple programs are
actively competing for resources resulting in higher degree of resource utilization.
Multiple Users − Multiprogramming supports multiple users.

12. Types of Operating System:
Multitasking
It is when multiple jobs are executed by the CPU simultaneously by switching
between them. Switches occur so frequently that the users may interact with each
program while it is running. An OS does the following activities related to
multitasking −
1. The user gives instructions to the operating system or to a program directly, and
receives an immediate response.
2. The OS handles multitasking in the way that it can handle multiple
operations/executes multiple programs at a time.
3. Multitasking Operating Systems are also known as Time-sharing systems.
4. These Operating Systems were developed to provide interactive use of a
computer system at a reasonable cost.
5. A time-shared operating system uses the concept of CPU scheduling and
multiprogramming to provide each user with a small portion of a time-shared CPU.
6. Each user has at least one separate program in memory.

13. Types of Operating System:
Multitasking
• A program that is loaded into memory and is executing is commonly referred to
as a process.
• When a process executes, it typically executes for only a very short time before
it either finishes or needs to perform I/O.
• Since interactive I/O typically runs at slower speeds, it may take a long time to
complete. During this time, a CPU can be utilized by another process.
• The operating system allows the users to share the computer simultaneously.
Since each action or command in a time-shared system tends to be short, only
a little CPU time is needed for each user.
• As the system switches CPU rapidly from one user/program to the next, each
user is given the impression that he/she has his/her own CPU, whereas actually
one CPU is being shared among many users.
In Time sharing systems the prime focus is on minimizing the response time,
while in multiprogramming the prime focus is to maximize the CPU usage.

14. Types of Operating System:Multitasking

15. Types of Operating System
Advantages
• Each task gets an equal opportunity.
• Chances of duplication of software is less.
• Idle time of CPU can be reduced.
Disadvantages
• Reliability problem
• One must have to take care of security and integrity of user programs and data
• Data communication problem

16. Types of Operating System:
Multiprocessor Systems
• A Multiprocessor system consists of several processors that share a common
physical memory.
• Multiprocessor system provides higher computing power and speed.
• In multiprocessor system all processors operate under single operating system.
• Multiplicity of the processors and how they do act together are transparent to
the others.
• It permits parallel processing.
• These operating systems include Windows NT, 2000, XP, and Unix.

17. Types of Operating System:
Multiprocessing Systems
Advantages of Multiprocessor Operating System:
• Enhanced performance
• Execution of several tasks by different processors concurrently, increases the
system's throughput without speeding up the execution of a single task.
• If possible, system divides task into many subtasks and then these subtasks
can be executed in parallel in different processors. Thereby speeding up the
execution of single tasks.
Disadvantages of Multiprocessor Operating System:
• Usually more expensive.
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18. Types of Operating System:
Network Operating System
• These systems run on a server and provide the capability to manage data,
users, groups, security, applications, and other networking functions.
• These type of operating systems allow shared access of files, printers, security,
applications, and other networking functions over a small private network.
• One more important aspect of Network Operating Systems is that all the users
are well aware of the underlying configuration, of all other users within the
network, their individual connections etc. and that’s why these computers are
popularly known as tightly coupled systems.
Note: Tightly Coupled Object is an object that needs to know about other objects
and are usually highly dependent on each other's interfaces. When we change
one object in a tightly coupled application often it requires changes to a number of
other objects.

19. Types of Operating System:
Network Operating System

20. Types of Operating System:
Network Operating System
Advantages of Network Operating System:
• Highly stable centralized servers
• Security concerns are handled through servers
• New technologies and hardware up-gradation are easily integrated to the
system
• Server access are possible remotely from different locations and types of
systems
Disadvantages of Network Operating System:
• Servers are costly
• User has to depend on central location for most operations
• Maintenance and updates are required regularly
Examples of Network Operating System are: Microsoft Windows Server 2003,
Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell NetWare, and
BSD etc.
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21. Types of Operating System:
Distributed Operating System
• Different autonomous interconnected computers communicate with each other
using a shared communication network. Independent systems possess their
own memory unit and CPU. These are referred as a loosely coupled system
or distributed system.
• This system’s processors differ in size and function.
• The major benefit of working with these types of operating system is that it is
always possible that one user can access the files or software which are not
actually present on their system but on some other system connected within
this network i.e., remote access is enabled within the devices connected in that
network.
• Different types of distributed operating system are:
 Client-Server Systems
 Peer-to-Peer Systems

22. Types of Operating System:
Distributed Operating System

23. Types of Operating System:
Distributed Operating System
An operating system does the following activities related to distributed
environment −
• The OS distributes computation logics among several physical processors.
• The processors do not share memory or a clock. Instead, each processor has
its own local memory.
• The OS manages the communications between the processors. They
communicate with each other through various communication lines.
Examples of Distributed Operating System are- LOCUS etc.
Difference:
In network operating system each node or system can have its own operating system
on the other hand in distribute operating system each node or system have same
operating system.

24. Types of Operating System:
Distributed Operating System
Advantages of Distributed Operating System:
• Failure of one will not affect the other network communication, as all systems
are independent from each other
• Since resources are being shared, computation is highly fast and durable
• Load on host computer reduces
• These systems are easily scalable as many systems can be easily added to the
network
• Delay in data processing reduces
Disadvantages of Distributed Operating System:
• Failure of the main network will stop the entire communication
• To establish distributed systems the language which are used are not well
defined yet
• These types of systems are not readily available as they are very expensive.
Not only that the underlying software is highly complex and not understood well
yet

25. Types of Operating System:
Real Time Operating System
• These are used when there are time requirements are very strict i.e. there are
deadlines for every task-input, output and processing.
• A real-time operating system must have well-defined, fixed time constraints,
otherwise the system will fail like missile systems, air traffic control systems,
robots, Scientific experiments, medical imaging systems etc.
• A real-time system is defined as a data processing system in which the time
interval required to process and respond to inputs is so small that it controls the
environment.
• The time taken by the system to respond to an input and display of required
updated information is termed as the response time. So in this method, the
response time is very less.

26. Types of Operating System:
Real Time Operating System
There are two types of real-time operating systems.
• Hard real-time systems
 Hard real-time systems guarantee that critical tasks complete on time.
 In hard real-time systems, secondary storage is limited or missing and the
data is stored in ROM.
 In these systems, virtual memory is almost never found.
• Soft real-time systems
 Soft real-time systems are less restrictive.
 A critical real-time task gets priority over other tasks and retains the priority
until it completes.
 Soft real-time systems have limited utility than hard real-time systems.
 For example, multimedia, virtual reality, Advanced Scientific Projects like
undersea exploration and planetary rovers, etc.

27. Types of Operating System:
Embedded Operating System
• An embedded operating system (OS) is a specialized operating system designed to
perform a specific task for a device that is not a computer. Embedded means
hidden.
• It’s main job is to run the code that allows the device to do its job.
• The embedded OS also makes the device’s hardware accessible to the software
that is running on top of the OS.
• Embedded operating systems are usually used for hardware that have very little
computing power, little RAM/ROM and a slow CPU
• It has limited features.
• Examples include computers in cars, traffic lights, digital televisions, ATMs, airplane
controls, point of sale (POS) terminals, digital cameras, GPS navigation systems,
elevators, digital media receivers and smart meters, among many other possibilities.
• The most common examples include Windows Mobile/CE (handheld Personal Data
Assistants), Symbian (cell phones Nokia) and Linux.

28. Types of Operating System
Type of operating
system
Features/benefits Example Applicable to which type of
application
Batch systems More than one job can
be stored in main
memory
Batches of same type
of jobs can be
executed quickly
FMS
(FORTRAN
monitor
system),
IBM’s
operating
system for
7094
Background jobs in which the
user interaction is not
necessary
Multiuser systems Jobs of different users
who are connected to
a main computer are
executed through the
multiprogramming
Interaction of jobs with
the user is possible
Debugging is easy
CTSS by MIT,
TSS by IBM,
MULTICS,
UNIX
When multiple users need to
share a single system

29. Types of Operating System
Type of operating
system
Features/benefits Example Applicable to which type of
application
Multitasking systems Multiple tasks of a
single user can be
opened on the system
through
multiprogramming
Windows When a user wants to open
and work simultaneously on
many windows on the system
Network systems The user is able to
connect to another
machine and perform
many operations
The user is aware of
the location of the
network node where
he/she wants to
connect
Novell
Netware,
Windows NT,
Windows
2000,
Windows XP,
Sun Solaris
When a user wants to remote
login on a system, wants to
transfer a file, etc. on a
network system

30. Types of Operating System
Type of operating
system
Features/benefits Example Applicable to which type of
application
Distributed systems When multiple nodes
of a wide network
realized as a powerful
machine sharing the
resources on the
network. The users
are not aware where
their processes are
being sent and
executed.
Amoeba, V
system,
Chorus
When computational speed
and resource sharing is
required and implemented
through various full computer
systems in a network
Real-time systems Used to handle time-
bound responses to
the applications
pSOS,
VxWorks,
RTLinux, etc.
Applicable to systems which
require time-bound response,
i.e., for the real-time
processing systems

31. Types of Operating System
Type of operating
system
Features/benefits Example Applicable to which type of
application
Embedded systems Specialized systems
with size, memory
and power restrictions
Palm Pilot,
Toshiba Pocket
PC, Palm OS,
Symbian OS,
iPhone OS,
RIM’s
BlackBerry,
Windows
Phone, Linux,
Palm WebOS,
Android and
Maemo.
Used in consumer electronics
items, mobile phones, smart
cards, etc.

32. Assignment
Q1. State differences between multiprocessor, network
and distributed operating system.
Q2. State advantages and disadvantages of Real time
operating system.
Q3.Multiprogramming is inherent in timesharing and
multitasking operating system. Justify.