Systems and Utility Programs OBJECTIVES After completing this lesson you should be able to Describe the two types of system software Describe the functions of an Operating System Understand the startup process on a personal computer ID: 660753
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Slide1
By Humphrey Kumwembe
Operating
Systems and
Utility ProgramsSlide2
OBJECTIVES
After completing this lesson, you should be able to:
Describe the two types of system software
Describe the
functions of an Operating System.
Understand the startup process on a personal computer.
Describe the term user
interface.
Summarize the features for stand-alone, server and embedded operating system.
Explain the purpose of several utility programs.Slide3
SYSTEM SOFTWARE
System
software consists of the programs that control or maintain the operations of the computer and its
devices.
Serves
as the interface between the user, the application software, and the computer’s
hardware.
System Software is divided into two types:
OPERATING SYSTEM(OS
)
DRIVERS
UTILITY PROGRAMSSlide4
OPERATING SYSTEM(OS)
Set of
programs that
coordinates
all activities among computer hardware resources.
Resides on optical disc or flash memory or Hard disk(Desktop computers) or ROM chip(Mobile and handheld devices).
Sometimes called platform.
An application software requires a platform to run.Some applications run on multiple platforms and these are Cross-platform programs. Slide5
OS FUNCTIONS
Starting up and Shutting down a Computer
The process of starting or restarting a computer is called
Booting
.
There is:
Cold booting
: Starting of computer when is powered off completely.Warm booting: Uses the operating system to restart the computer. (Done after installing updates or new software)
The kernel and frequently used operating system instructions are loaded each time a computer is booting.
Kernel
: Core of the OS:
Manages memory and devices.
Starts programs.
Maintains computer’s clock.
Assign computer resources(Devices, programs, data etc.)Slide6
OS FUNCTIONS
Boot process is done in 7 steps:
When you turn on the computer, the power supply sends an electrical signal to devices located in the system
unit
The processor chip resets itself and looks for the ROM chip that contains the
BIOS
(
basic input/output system), which is firmware that holds the startup instructions.The BIOS executes the
power-on self test
(
POST
) to make sure hardware is connected properly and operating correctly
.
The POST results are compared with data in a CMOS chip on the motherboard
. The CMOS chip stores information about;
Memory amount
Disk drive types
Keyboard and monitor.
Current date and time.
If the POST completes successfully, the BIOS searches for specific operating system files called
system files
.Slide7
OS FUNCTIONS
Once
located, the
boot drive
(the drive from which your personal computer starts), loads the system files from storage (the hard disk – usually drive C) into memory (RAM) and executes them. Next, the kernel of the operating system loads into memory and takes control of
the computer.
The operating system loads configuration
information. The registry consists of several file that contain the system configuration information that are constantly accessed by the OS i.e. Hardware and software devices installed and individual user preferences.
Shutdown options:
Powering off the computer: This is total shutdown where all processes are completely killed.
Sleep mode: Keeps session(Programs and documents) in Memory(RAM), turns off all unneeded functions and place computer in low-power state. If power is removed, all unsaved content is lost.
Hibernate: Saves any open documents and programs to a hard disk before removing power from the computerSlide8
OS FUNCTIONSSlide9
OS FUNCTIONS
Providing User Interface(UI)
I
s
the space where interaction between humans and machines
occurs.
C
ontrols how you enter data and instructions and how information displays on the screen.Two types:Graphical User Interface(GUI): A
graphical user interface
(
GUI
) allows you to use menus and visual images such as icons, buttons, and other graphical objects to issue
commands.
Command-line Interface:Slide10
Graphical user InterfaceSlide11
Command-Line InterfaceSlide12
OS FUNCTIONS
Managing Programs
Some operating systems support a single user and only one running program at a time. Others support thousands of users running
multiple
programs
.
How programs are managed affects productivity.
A single user/single tasking: Operating
system allows only one user to run one program at a
time i.e. Dos OS
A
single user/
multitasking:
Operating
system allows a single user to work on two or more applications that reside in memory at the same time.
A program may run in foreground(Active) or background(Not in use).
A
multi-user:
Operating
system enables two or more users to run a program simultaneously
. i.e. Server OS.
A
multiprocessing:
Operating
system supports two or more processors running programs at the same time. Multiprocessing involves the coordinated processing of programs by more than one processor.
Multiprocessing increases a computer’s processing speed.Slide13
OS FUNCTIONS
Managing memory
The purpose
of
memory
management
is to optimize use of random access memory (RAM
).OS allocates or assigns items to memory area while they are being processed. Monitors the contents of memory.OS releases the contents from memory when no longer required.If programs a lot of memory space, OS uses virtual memory to solve the problem.
With
virtual memory
(
VM
), the operating system optimizes memory by allocating a portion of a storage medium, usually the hard disk, to function as additional
RAM.Slide14
OS FUNCTIONS
Coordinating tasks.
Scheduling
jobs
(operations the processor manages) involves determining the order in which jobs are
processed.
Configuring
devices.A device driver is a small program that tells the operating system how to communicate with a
device.
Most OS and Devices
support Plug-and-Play.
Plug
and Play means the operating system automatically configures new devices as you install
them.
Monitoring performance
.
OS monitors the performance of the system.
Monitoring
performance helps to identify and solve system
problems.
A
performance monitor
is a program that assesses and reports information about various system resources and devicesSlide15
OS FUNCTIONS
Provide file management and other
utilities
OS provide users with capabilities to manage files.
Uses File Manager to:
format
and copy disks; List the files on a storage medium;
C
heck
the amount of used and unused space on a storage
medium;
Organize, copy, delete, move,
and
sort
files;
Create
shortcuts
(icons on the desktop that run a program when clicked).
Administering security
.
Administering security involves establishing user accounts on a network.
Each
account typically requires a
user name
and
password
to
log on
, or access, the network.Slide16
OS TYPES
The three basic categories of OS:
Stand-Alone OS
:
A
stand-alone operating system
is a complete operating system that works on a desktop or notebook or mobile computer. Some stand-alone OS have networking capabilities allowing them to in conjunction with server OS(Client OS).
Examples include Windows 8, Windows 7, Vista, Windows XP, Linux, Mac OS X, Unix, DOS(Disk Operating System) Windows 3.1.
Server OS
:
OS designed to support a network.
Client computers rely on server resources.
Resource may include data, services, memory etc.
Examples include Windows server 2008, Linux, Unix, Windows Server 2003.
Embedded OS
:
OS
on mobile devices and many consumer
electronics.
Resides on ROM Chip.
Examples include Windows Embedded CE, Google Android, Palm OS, iPhone OS, BlackBerry.Slide17
UTILITY PROGRAMS
P
rograms
that perform specific tasks related to managing a computer, its devices, or its
programs.
Include:
File
Manager: A utility that performs functions related to file management i.e. Listing of files on Storage medium, copying, deleting, moving and sorting files.
Search
Utility
:
A program
that attempts to locate a file on your computer based on criteria you
specify. Criteria may be word or words in a file.
Disk Defragmenter
: A
utility that reorganizes files and unused space on a computer’s hard disk so data can be accessed more quickly and programs can run faster
Back up and
Restore
: A backup utility allows users to copy, or back up, selected files or an entire hard disk to another storage medium
i.e. another hard disk
, flash disk.
Restore
utility reverses the process and returns backed up files to their original
form. Backup utilities work with and restore utilities
Personal
firewall
:
A
utility that detects and protects a personal computer from unauthorized intrusions. Personal firewalls constantly monitor all transmissions to and from a
computer.Slide18
UTILITY PROGRAMS
Spyware and Adware removers
:
Spyware
is a program placed on a computer without the user’s knowledge that secretly collects information about the user, often related to Web browsing
habits.
Adware is a program that displays an online advertisement in a banner or pop-up window on Web pages, e-mail, or other Internet services
.
Sometimes, spyware is hidden in adware
.
A
spyware and Adware remover
is a program that
detects ad removes spyware and adware
File compression
:
S
hrinks
the size of a
file.