1. Operating Systems Chapter 2 B.M.H

2. Learning Objectives

Software Classification

System Software

Operating System

OS of PCs

NOS

MIU 3. Computer System

Hardware

• Input devices

• Processor (CPU)

• Output devices

• Secondary storage

Software

• System software

• Application software

People

MIU 4. Software

System software

all programs related to coordinating computer operations

• Operating systems

• Programming language translators

• A variety of utility programs

Application software

allows user to perform useful work

• Word processing, spreadsheet software, etc

MIU 5. System SW

When you think of a computer, what first comes into your head?

• The physical component

• • like the monitor, keyboard, or mouse

• The applications that run on your computer

• • like word processing, video game, internet browsing

MIU 6. Operating System

Anoperating systemis the software needed to communicateapplication programsand computerhardwareto each other. (called OS)

MIU 7. OS MIU 8. OS

Serves as a intermediary

• between the applications software and the hardware

The fundamental software

• that controls access to all other hardware and software resources

MIU 9. OS

A set of programs

• that lies between the applications software and the hardware

• Kernel: the most important program in OS

• Can be divided as remaining in memory

• • Resident : Kernel

• • Nonresident : other OS programs

MIU 10. Kernel

The program that manages the OS

Most of it remains in memory

• Referred to asresident

Controls the entire OS

Loads into memory other OS programs (called nonresident) from disk storage only as needed

MIU 11. Kernel MIU A kernel connects the application software to the hardware of a computer. 12. Booting

The process of loading the OS into memory

When computer is turned on,

• A small program stored in a ROM chip performs some internal HW component tests,

• Then loads the kernel from the hard drive into the computer s memory

Calledbootstrapping

MIU 13. OS

Three main functions

• Managing the computer s resources,

• • such as the CPU, memory, disk drives and printers

• Establishing auser interface

• Executing and providing services for applications software

MIU 14. User interface

Determines how the user interacts with the OS

• Interface : inter + face

• : a way of presenting information to and obtaining information from a user

Two basic forms

• Command-line interface

• Graphical user interface (GUI)

MIU 15. User interface

Command-line interface

• Text-based

• Requires you to type in complete OS commands

• Ex) MS-DOS, Unix, Linux, many large-computer OSs

Graphical user interface (GUI)

• Visual images and menus to allow users to enter commands

• Ex) Windows, Mac OS, some installations of Linux and Unix

MIU 16.

OSs for Personal Computers

OSs for Networks

OSs for Large Computer Systems

MIU Index 17. OS for personal computers

When you buy something for your computer, you must know

• not only the OS the computer has,

• but also about itsplatform

MIU 18. OSs for Personal Computers

The SW is grouped according to the platform, on which the SW can run.

Platform

• A combination of computer hardware and operating system software

• Most common families of platforms

• • Windows family : (referred as Wintel)

• • • Microsoft Windows + Intel processor based PC

• • Macintosh family

• • • Mac OS + Motorola processor

• • Unix family

• • • Unix + all families of processors

MIU 19. MIU 20. MS-DOS

Called DOS (Disk Operating System)

Command-line user interface

• C: (disk drive)

• > : prompt

• • a signal that the system is prompting you to do something

• • the only visible result of booting

• • At this point, you must type command

MIU 21. Microsoft Windows

GUI

• Icons, menus (pull-down menus, pop-menus)

Three branches serving different users

• Home/consumer market

• • Windows 9x (95, 98, ME)

• Corporate market

• • Windows NT, 2000

• Both the consumer and corporate

• • Windows XP

• For pocket computers and Internet appliance

• • Windows CE

MIU 22. MIU 23. MAC OS

The first commercially successful GUI

• Based on concepts developed at Xerox s PARC research center in Palo Alto, California

MAC OS X

• Enhancement in multimedia support and multitasking-the ability to do several things at once.

MIU 24. MIU 25. UNIX

A multiuser time-sharing OS

A character-based system with a command-line user interface

The primary OS in use on Internet server, today

Run on about every type of computer available from microcomputers to mainframes

MIU 26. LINUX

Linus Torvalds, a student at the Univ. Of Helsinki in Finland

• Created the kernel of a Unix-like OS

• Made the source code available to the public free of charge

Command-line interface, also provide a GUI

MIU 27. OSs for Networks

NOS (Network Operating System)

• An extension of OSs for PCs

• Designed to let computers on a network share resources

• Similar to a standard OS but include special features for handling network functions

• Ex) Windows 2000

MIU 28. NOS

Functions

• Resource sharing on a network

• • Such as hard disks and printers

• Data security

• • Does this user have the right to that data?

• Troubleshooting

• • Computer *** on the network failed to receive a message intended for it

• Administrative control

• • Track the online hours and track the number of messages to and from each computer

MIU 29. NOS

In a client/server relationship

• Parts of the NOS : on Server computer

• • file access, management programs

• Other NOS components : on Client computer