AIOU SOLVED ASSIGNMENTS 2019

AIOU
Solved Assignments 2019
Assignment # 2 of 1431
Spring 2019

Question No # 1

Q.1 Differentiate between system software and application software.

Answer:-

System Software:-
System software is a set of one or more programs, which controls the operation
and / or extends the processing capability of a computer system. In general, a
computer’s system software performs one or more of the following functions:
1- Supports development of other application software.
2- Supports execution of other application software.
3- Monitors effective use of various hardware resources such as CPU, memory,
peripherals, etc.
4- Communicates with and controls operation of peripheral device such as
printer, disk, tape, etc.
Hence, system software makes the operation of a computer system more
effective and efficient. It helps hardware components work together, and
provides support for the development and execution of application software
(programs). Programs included in a system software package are called system
programs, and programmers who prepare system software are referred to as
system programmers.

Types of system software:

Some commonly known types of system software are:

1- Operating systems:

               Operating system software takes care of effective and efficient utilization of
all hardware and software components of a computer system.

2- Programming language translators:

Programming language translators transform the instructions prepared by
programmers in a programming language into a form that can be interpreted and
executed b a computer system.

3- Communications software:

In a network environment (where multiple computers are interconnected
together by communications network communications software enables transfer
of data and programs from one computer system to another.

4- Utility programs:

Utility programs (also known as utilities) are a set of programs that help
users in system maintenance tasks, and in performing tasks of routine nature.
Some tasks commonly performed by utility programs include formatting of hard
disks or floppy disks, taking backup of files stored on hard disk on to a tape or
floppy disk, sorting of the records stored in a file based on some key field(s), etc.

Question No # 2

Q.2 what is meant by operating system? Define it in detail with the help of suitable examples?

Answer:-

Operating System:-

Operating system (often referred to as OS) is an integrated set of programs
that controls the resources (CPU, memory, I/O device, etc.) of a computer system

and provides its users with an interface or virtual machine that is easier to use
than the bare machine.

Objectives of Operating system:

According to this definition, the two primary objectives of an op system
are:
1- Make a computer system easier to use:
A computer system consists of one or more processor, main memory, and
many types of I/O devices such as disks, tapes, terminals, network interfaces, etc.
writing programs for using these hardware resources correctly and efficiently is
an extremely difficult job, requiring in-depth knowledge of functioning of these
resources. Hence, to make computer systems usable by a large number of users,
it became clear several years ago that computer systems need some mechanism
to shield programmers and other users from the complexity of hardware
resources. Researchers gradually evolved a solution to handle this problem by
putting a layer of software on top of the bare hardware. This layer of software
manages all hardware resources of the system, and presents the users with an
interface or virtual machine that is easier, safer, and efficient to program and use.
It is called the operating system.

2- Manage the resources of a computer system:
An operating system manages all the resources of a computer system. This
involves performing such tasks as keeping track of who is using what resources,
granting resource requests, accounting for resource usage, and mediating
conflicting requests from different programs and users. Efficient and fair sharing
of system resources among users and / or programs is a key goal of all operating
systems.

Main Functions of an operating system:
Most operating systems perform the functions given below. A separate
module of operating system software performs each of these functions:

1- Process management:
A process is a program in execution. During execution a process needs
certain resources such as CPU time, memory space files and I/O devices. At a
particular instance of time a computer system normally consists of a collection of
processes. Process management module takes care of creation and deletion of
processes, scheduling of system resources to different processes requesting
them, and providing mechanisms for synchronization and communication among
processes.
2- Memory management:
To execute a program, it must be loaded in main memory (at least
partially), together with the data it accesses, to improve CPU utilization and to
provide better response time to its users, a computer system normally keeps
several programs in main memory. Memory management module takes care of
allocation and de-allocation of memory space to programs in need of this
resource.
3- File management:
All computer systems store, retrieve, and share information. Normally, a
computer stores such information in units called files. Processes read information
from files and create new files for storing newly generated information. File
management module takes care of file-related activities such as organization,
storage, retrieval, naming, sharing, and protection of files.
4- Device management:
Normally, a computer system consists of several I/O devices such as
terminal, printer, disk, and tape. The device management module of an operating
system controls all I/O devices. It keeps track of I/O requests from processes,
issues commands to I/O devices, and ensures correct data transmission to / from
an I/O device. It also provides a simple and easy to use interface between the
devices and rest of the system.
5- security:
Computer systems often store large amount of information, some of which
are highly sensitive and valuable to their users. Users can trust a computer system
and rely on it only if its various resources and information stored in it are
protected against destruction and unauthorized access. Security module protects
the resources and information of a computer system against destruction and
unauthorized access. It also ensures that when the system executes several
disjoint processes simultaneously, one process does not interfere with others or
with the operating system itself.