3. Software
A collection of instructions that tells
the computer what to do
OR
“Software is a
single/collection of
programs that performs a
particular task.”
4. The greatest mind behind the 1st
software
The world's first stored-
program electronic digital
computer, the English Small
Scale Experimental
Machine (SSEM, nicknamed
the Baby) successfully
executed its first program on
21st June 1948. That program
was written by Tom Kilburn,
who actually built the machine,
designed by his mentor
Tom Kilburn
6. System software
System software is computer
software designed to operate the
computer hardware and to provide
and maintain a platform for running
application software.
7. Programming software
It is used for providing tools
to the programmer for writing
computer programs and
software by using
programming languages.
11. Examples
• Examples of System Software's are:
• Operating Systems
• Utility Programs
• Device Drivers
M. Hammad Waseem 11
12. Operating System (OS)
• 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. 12
13. 13
System Software: The OS
Controls computer functions
Processor
Hardware
Memory etc.
Provides means for software to work with the CPU
Responsible for management, scheduling, and
interaction of tasks
Provides user interface
14. System Software: Utilities
• A program that performs a specific task
related to the management of computer
functions, resources, or files,
as password protection, memory management, vi
rus protection, and file compression.
• Utility software helps to manage, maintain and
control computer resources(System memory,
cache memory, hard disk space, are examples.)
15. 15
System Software: Utilities
• Utilities: Programs that perform
computer housekeeping tasks
• Manage system resources
• Improve efficiency
• Virus prevention
• system maintenance and
• file compression.
25. 25
System Backup
• Backup
• Creates a copy of a hard drive to another storage
device
• When you use the Windows Backup utility,
you create a duplicate copy of all the data on
your hard disk and copy it to another storage
device, such as a CD or an external hard
drive
26. Device Driver
• A Device Driver is a computer
program that operates or controls a
particular type of device that is
attached to a computer.
• Like printers
• CD-ROM readers
26
27. CONT…
• The sole purpose of a device driver is to
instruct a computer on how to
communicate with the input/output device
(I/O) by translating the operating system's
I/O instructions into a language that a
device can understand. There are various
types of device drivers for I/O devices such
as keyboards, mice, CD/DVD drives,
controllers, printers, graphics cards and
ports.
29. Real T ime Operating System
• Real time operating system mean quick
response or
• That guarantee a cretin capability within a
specify time constraint. E.g. Radar control
system
30. Real-Time Systems
– Fastest and are used in time-critical
environment
– Data must be processed extremely quickly
because the output influence immediate
decisions
– Must be 100% responsive 100% of the time.
Response time measured in fraction of sec
– Used in space flight, military system,
airport traffic control, high-speed aircraft,
industrial processes, sophisticated
medical equipment etc.
32. 32
Single-User Operating Systems
Single-task systems
• Perform one task at a time
• Pocket PC
• Palm OS ORpalmtop,
• Windows Mobile
Multitask systems
• Perform simultaneous tasks
• Windows
33. Multi tasking
• Whereas multitasking means performing
multiple tasks in parallel. Usually, CPU
processes only one task at a time but the
switching of CPU between the processes
(also known as Context Switching) is so fast
that it looks like CPU(or processor) is
executing multiple processes at a time.
Example of multitasking, we listen to music
and do internet browsing at the same time
(they execute parallely).
34. Multiuser Operating Systems
• A multiuser operating system (also known as a
network operating system) enables more than
one user to access the computer system at one
time by efficiently manipulating all the requests
from multiple users.
• Networks require a multiuser operating system
because many users access the server
computer at the same time and share
resources.
• Examples include Linux,UNIX etc.
35. 35
Operating Systems for
Servers and Mainframes
• Servers
• Manage network resources
• Mainframes
• Handle requests from hundreds or thousands
of users simultaneously
• Operating systems:
• Windows Server
• Unix
36. 36
The User Interface
• Enables you to interact
with the computer
• Types of interfaces:
• Command-driven
interface
• Menu-driven interface
• Graphical user interface
(GUI)
Command-driven
37. 37
Starting the Computer
The Boot Process
• Step 1: The basic input/output system (BIOS) is activated.
• Step 2: A power-on self-test (POST) checks attached hardware.
• Step 3: The operating system loads into RAM.
• Step 4: Configuration and customization settings are checked.
39. 39
Windows
Title bar Close button
Ribbon
Minimize button
Maximize/Restore
button
Scrollbar
Document view
options
40. 40
File Management
• The operating system provides an
organizational structure for the computer’s
contents.
• Hierarchical structure of directories:
• Drives
• Folders
• Subfolders
• Files
41. 41
Working with Files
• File management actions:
• Open
• Copy
• Move
• Rename
• Delete
• Recycle Bin
43. 43
System Backup
• Backup
• Creates a copy of a hard drive to another storage
device
• When you use the Windows Backup utility,
you create a duplicate copy of all the data on
your hard disk and copy it to another storage
device, such as a CD or an external hard
drive