DOS with Windows 3.1 and 3.11 Operating Environments

Designed to allow applications to have a graphical interface

DOS runs in the background as the true OS and uses Windows 3.x as the middle layer between the application and DOS

Has been replaced with Windows 9x

Windows 95 and 98

Do not completely eliminate DOS

Windows 95

Windows for Workgroups (Windows 3.11) plus DOS 7.0

Introduced Plug and Play capability

Windows 98

Supports larger hard drives and more hardware devices

Includes more software utilities

Faster than Windows 95

The last Microsoft OS with a DOS foundation

Windows 9x

UNIX

Originally written for mainframe computers in the early 1970s

Now a popular OS for networking

Linux

A variation of UNIX that is free to everyone

UNIX

Linux Offshoot of Unix

Works on X86 or “Wintel” PC’s

Freely distributed version of UNIX

Open source code (GNU)

Growing in popularity

Has many Windows features

Both command based and GUI based (X Windows)

Windows NT

Completely eliminates the underlying relationship with DOS

Supports preemptive multitasking and multiprocessing

Designed to work within a powerful networked environment (client/server)

Windows NT

Windows 2000

A suite of operating systems, each designed for a different sized computer system

Windows 2000 Professional

Windows 2000 Server

Windows 2000 Advanced Server

Windows 2000 Datacenter Server

Built on Windows NT architecture

Designed to ultimately replace both Windows 9x for low-end systems and Windows NT for midrange and high-end systems

Windows 2000

OS/2

Written by IBM in cooperation with Microsoft Corporation

Provides an altogether different OS in place of DOS

Slow to gain popularity due to:

Errors in earlier versions

Large computer hardware requirements

OS/2

Macintosh Operating System

Available only on Macintosh computers

Offers easy access to the Internet

Allows any Macintosh computer to become a Web server for a small network

Macintosh Operating System

How an Operating System Manages an Application

DOS naming conventions

Filename (up to 8 characters)

File extension (3 characters)

Memory addressing under DOS

Operating System Capabilities

Operating systems have different basic functions and Capabilities.

They can be single tasking, single user, multi-tasking, multi-user, and Network Capable

Network Capable

Operating systems can include

Local Area Networking

Each PC Shares its resources, often called Peer to Peer

Client Server Networking

One or more PC’s act as a File or Printer, or other type of server

Other PC’s are clients, They log on to the server and use its services

Single Tasking

Performs only one job, then can do another

Batch Mode

Jobs are given in batches, performed one after the other

Command Line Mode

User types or otherwise enters commands one at a time to the computer

Multi-Tasking

multiple jobs done simultaneously, usually by time slicing

Multi-Threading-Capability to split jobs into threads and do each separately

Multi-User Multiple Simultaneous Users

Operating System Modes

Real mode

Single-tasking operating mode whereby programs:

Only have 1024K of memory addresses

Have direct access to RAM

Use a 16-bit data path

Protected mode

Supports multitasking whereby:

The OS manages memory

Programs have more than 1024K of memory addresses

Programs can use a 32-bit data path

Real Mode

Protected Mode

Applications Software

Designed to work on top of a particular OS

Comes written on floppy disks or CD-ROMs; usually must be installed on a hard drive in order to run

Categories of Applications Software

Word processing

Spreadsheet

Database management

Graphics

Communications

Games

Mathematical modeling

Software development tools

How Applications Software is Loaded and Initialized

OS receives command to execute application

OS locates program file for the application

OS loads program file into memory

OS gives control to the program

Program requests memory addresses from OS for its data

Program initializes itself; it may request that data from secondary storage be loaded into memory

Program turns to user for its first instruction

How Applications Software is Loaded and Initialized

Launching a Program File

Rules DOS Uses to Search for Executable Program Files

If no path is given before the filename, DOS looks in the current directory

If no path is given and the file is not in current directory, DOS looks in paths given to it by the last PATH command executed

If there is a path given in front of filename in the command line, DOS looks in that path

If there is a path given but the file is not found in that path, DOS looks in paths given to it by the last PATH command executed

Copying the Program into Memory

Loading Application Software Using Windows 9x

Place shortcut icon directly on desktop

Click Start button; select Programs; select program from list of installed software

Use Run command, after clicking Start button on the taskbar

Loading Application Software Using Windows 9x

Applications Software Summary

Applications software is executed by either the operating environment (Windows 3.x) or the OS software (DOS or Windows 9x)

When an application is executing, you are interacting with the application

Applications software interacts with OS software that is executing it

OS software interacts with hardware

OS software might interact with the hardware through BIOS or the device driver

Chapter Summary

Individual components that make up a computer system: hardware and software

Hardware

Devices used for input, output, processing, and storage of data

Components that make up the electrical system

Components used for communicating data and instructions from one device to another

Importance of buses on the system board

Chapter Summary

CPU

Central processing point for all data and instructions

Both data and instructions must be stored in memory with assigned memory addresses before processing can begin

Chapter Summary

Software

Works in layers

Lowest layer (BIOS and device drivers) interfaces with hardware

Highest layer (applications software) interfaces with user

OS is the middleman layer that coordinates everything


	Designed to allow applications to have a graphical interface
		DOS runs in the background as the true OS and uses Windows 3.x as the middle layer between the application and DOS
	Has been replaced with Windows 9x


	Do not completely eliminate DOS
	Windows 95
		Windows for Workgroups (Windows 3.11) plus DOS 7.0
		Introduced Plug and Play capability
	Windows 98
		Supports larger hard drives and more hardware devices
		Includes more software utilities
		Faster than Windows 95
		The last Microsoft OS with a DOS foundation


	Originally written for mainframe computers in the early 1970s
	Now a popular OS for networking
	Linux
		A variation of UNIX that is free to everyone


	Works on X86 or “Wintel” PC’s
	Freely distributed version of UNIX
	Open source code (GNU)
	Growing in popularity
	Has many Windows features
	Both command based and GUI based (X Windows)


	Completely eliminates the underlying relationship with DOS
	Supports preemptive multitasking and multiprocessing
	Designed to work within a powerful networked environment (client/server)


	A suite of operating systems, each designed for a different sized computer system
		Windows 2000 Professional
		Windows 2000 Server
		Windows 2000 Advanced Server
		Windows 2000 Datacenter Server
	Built on Windows NT architecture
	Designed to ultimately replace both Windows 9x for low-end systems and Windows NT for midrange and high-end systems


	Written by IBM in cooperation with Microsoft Corporation
	Provides an altogether different OS in place of DOS
	Slow to gain popularity due to:
		Errors in earlier versions
		Large computer hardware requirements


	Available only on Macintosh computers
	Offers easy access to the Internet
	Allows any Macintosh computer to become a Web server for a small network


	DOS naming conventions
		Filename (up to 8 characters)
		File extension (3 characters)
	Memory addressing under DOS


	Operating systems have different basic functions and Capabilities.
	They can be single tasking, single user, multi-tasking, multi-user, and Network Capable


Operating systems can include
	Local Area Networking
		Each PC Shares its resources, often called Peer to Peer
	Client Server Networking
		One or more PC’s act as a File or Printer, or other type of server
		Other PC’s are clients, They log on to the server and use its services


Performs only one job, then can do another
	Batch Mode
		Jobs are given in batches, performed one after the other
	Command Line Mode
		User types or otherwise enters commands one at a time to the computer


		multiple jobs done simultaneously, usually by time slicing
		Multi-Threading-Capability to split jobs into threads and do each separately


Real mode
	Single-tasking operating mode whereby programs:
		Only have 1024K of memory addresses
		Have direct access to RAM
		Use a 16-bit data path
Protected mode
	Supports multitasking whereby:
		The OS manages memory
		Programs have more than 1024K of memory addresses
		Programs can use a 32-bit data path


	Designed to work on top of a particular OS
	Comes written on floppy disks or CD-ROMs; usually must be installed on a hard drive in order to run


	Word processing
	Spreadsheet
	Database management
	Graphics
	Communications
	Games
	Mathematical modeling
	Software development tools


	OS receives command to execute application
	OS locates program file for the application
	OS loads program file into memory
	OS gives control to the program
	Program requests memory addresses from OS for its data
	Program initializes itself; it may request that data from secondary storage be loaded into memory
	Program turns to user for its first instruction


	If no path is given before the filename, DOS looks in the current directory
	If no path is given and the file is not in current directory, DOS looks in paths given to it by the last PATH command executed
	If there is a path given in front of filename in the command line, DOS looks in that path
	If there is a path given but the file is not found in that path, DOS looks in paths given to it by the last PATH command executed


	Place shortcut icon directly on desktop
	Click Start button; select Programs; select program from list of installed software
	Use Run command, after clicking Start button on the taskbar


	Applications software is executed by either the operating environment (Windows 3.x) or the OS software (DOS or Windows 9x)
	When an application is executing, you are interacting with the application
	Applications software interacts with OS software that is executing it
	OS software interacts with hardware
	OS software might interact with the hardware through BIOS or the device driver


Individual components that make up a computer system: hardware and software
Hardware
	Devices used for input, output, processing, and storage of data
	Components that make up the electrical system
	Components used for communicating data and instructions from one device to another
		Importance of buses on the system board


	CPU
		Central processing point for all data and instructions
		Both data and instructions must be stored in memory with assigned memory addresses before processing can begin


Software
	Works in layers
		Lowest layer (BIOS and device drivers) interfaces with hardware
		Highest layer (applications software) interfaces with user
	OS is the middleman layer that coordinates everything