1. Introduction to Operating Systems
Chapter 1
Introduction to Operating Systems

2. Hardware Needs Software to Work
Physical components of the computer (monitor, keyboard, memory chips, hard drive, etc.)
Software
Set of instructions that directs hardware to accomplish a task

3. Hardware Needs Software to Work

4. Software
Programs written by programmers that instruct computers to perform specific task.
PC Software
Firmware (BIOS)
Operating Systems (OS)
Applications software
BIOS and OS
Control the computer when it is first turned on

5. Software BIOS and OS Control the computer when it is first turned on
Startup
BIOS
Operating
System
Hardware
1.-Performs startup tasks
2.-Passes control to OS
3.-Performs more startup
tasks

6. O. S During Operation O.S. is serving as a middle layer between
User
Application Software
Operating System
BIOS
Device
Drivers
H a r d w a r e
During Operation
O.S. is serving as a middle layer between
app software and hardware
O.S. controls the allocation and use hardware

7. O. S. Components
This component tracks every file in the system
The kernel's primary purpose is to manage the computer's resources and allow other programs to run and use these resources.

8. O. S Operating System’s Tasks Memory Management Device Management
Allocates portions of memory to programs at their request
Device Management
Recognizing input from the keyboard or mouse
Sending output to the video screen or printer
Storage Management
Keeping track of files on the storage devices and hard drives
Application Interface
Ensures that applications continue to run when hardware upgrades and updates occur.
User Interface
GUI
Command line

9. O. S (Tasks)
Applications
Operating
System
Kernel

10. Single and Multi-User O. S.
Single User/Single Tasking
Allows only one user to run one program at a time.
Multi-User:
Allows 2 or more users to run programs at the same time (some OS permit hundreds or even thousands of concurrent users)
Multitasking
Allows more than one program to run concurrently
Multiprocessing
Supports running a program on more than one CPU
Multithreading
Allows different parts of a single program to run concurrently
Real Time
Responds to input instantly. General-purpose OS, such as DOS and UNIX, are not real-time.

11. Single and Multi-User O. S.
System
Single user
Multi-user
Single task
DOS X
Windows3.1
Windows95/98/Me
WindowsNT/2000
WindowsXP
Unix / Linux
MAC/OS X
VMS

12. Network O. S. (NOS)
Network operating systems (NOS) coordinate the activities of multiple computers across a network.
The network operating system acts as a director to keep the network running smoothly.
The two major types of network operating systems are:
Peer-to-Peer or
Workgroup model
Client/Server

13. Network O. S. (NOS) Peer-to-Peer Examples: AppleShare and
Users share resources and files located on their computers and to on other computers
Do not have a file server or centralized management
All computers have the same ability to use the resources available on the network
It is designed primarily for small to medium local area networks
Peer-to-Peer Examples:
AppleShare and
Windows for Workgroups
The file servers provide access to resources and security.
It provides the mechanism to integrate all the components of the network
Allows the network to centralize functions and applications in one or more dedicated file servers
When server goes down, operations will cease across the network.
Multiple users can simultaneously share the same resources irrespective of physical location.
All components (client/network/server) work together
Individual workstations (clients) have access to the resources available on the file servers.
Client/Server Examples:
Novell Netware
and
Windows NT Server .