Introduction to Operating Systems

1
Introduction to Operating Systems

• Part I Operating Systems Overview
• Part II Operating Systems in Practice
• (focusing on Windows and Linux)
• PLEASE MAKE COPIES OF LINSPIRE LIVE-CD FOR LAB
  PRACTICE THIS WEEK

2
Early Computers

• Charles Babbage (1791-1871) designed the first
  true digital computer called the analytical
  engine.
• That was purely mechanical and intended to do
  math operations
• The engine was supposed to be made of brass, and
  steam powered
• He did not actually built the machine but
  inspired others in the field.

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Early Computers

• Babbage also thought of the concept of software
• And hired the first programmer (Lady Ada,
  Countess of Lovelace) for his analytical machine

4
Current Computer Systems

• A computer system consists of
• hardware
• system programs
• application programs

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What is an Operating System

• It is the software that enables us to use the
  hardware
• It is a resource manager
• Allocates system resources such as I/O devices,
  CPU etc
• Schedules different jobs etc

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History of Operating Systems

• First generation 1945 - 1955
• vacuum tubes, plug boards
• Still very slow and used for scientific
  calculations
• No OS was needed
• Programs were entered by setting some switches

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History of Operating Systems

• Second generation 1955 1965
• transistors, batch systems
• Universities started to buy computers (spending
  millions of dollars)
• Punched cards were used
• To run a job (a program or a set of related
  programs) first punch it and give the deck to the
  operators and wait for the output (batch
  operation)
• Computers were single user

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History of Operating Systems

• Third generation 1965 1980
• Integrated Circuits
• Engineer at the Advanced Computing Systems
  Division of IBM, 1968, commenting on the
  microchip
• "But what ... is it good for?"

9
Famous Remarks

• "I have traveled the length and breadth of this
  country and talked with the best people, and I
  can assure you that data processing is a fad that
  won't last out the year.
• The editor in charge of business books for
  Prentice Hall - 1957

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History of Operating Systems

• Multiprogramming system
• three jobs in memory 3rd generation

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History of Operating Systems
The concept of spooling was introduced by 3rd
generation operating systemsand a memory
partition was available, it is loaded directly to
memory. Third generation OSs were still not
interactive, i.e., whenever there is an error,
programmers would realize it after a couple of
hours. This problem lead to timesharing systems
where the user has an online terminal
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History of Operating Systems

• Tanenbaum wrote a version of UNIX called MINIX
  with POSIX support for educational use.
• A Finnish student Linus Torvalds wrote a free
  production of MINIX called Linux

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History of Operating Systems

• Fourth generation 1980 present
• Personal computers were developed after LSI
  (Large Scale Integration) circuits were invented.
• First Microcomputer
• Intel 8080 CPU attached 8-inch floppy disk
• First disk based OS CP/M (Control Program for
  Microcomputers)
• In 1980s IBM designed the IBM PC and contacted
  Bill Gates for an operating System

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Brief History of Operating Systems Development
Recent Developments Distributed computing,
personal computers, high-speed communication,
multi-media
Second Generation Job scheduling, JCL, faster
I/O, spooling, batch, files
1940 1955 1965
1980 1990
First Generation Vacuum tube, single user, early
operating systems
Third Generation Shared processing,
multiprogramming, virtual memory, DBMS
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Famous Remark

• There is no reason anyone would want a computer
  in their home.
• Ken Olson, president, chairman and founder of
  Digital Equipment Corp. - 1977

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History of Operating Systems

• Bill Gates suggested IBM that they should look at
  CP/M (one of the the most successful OS for
  microcomputers at that time, by Gary Kildall)
• The biggest mistake of all
• Kindall refused to sign a non-disclosure
  agreement
• IBM went back to Bill Gates and signed a contract
  with him to write an OS for their new home
  computer
• MS-DOS was based on QDOS, the "Quick and Dirty
  Operating System" written by Tim Paterson of
  Seattle Computer Products,
• QDOS was based on Gary Kildall's CP/M
• Microsoft bought the rights to QDOS for 50,000

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Famous Remark

• "I think there is a world market for maybe five
  computers."
• Thomas Watson, chairman of IBM - 1943

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History of Operating Systems

• Early MS-DOS was very primitive but later
  versions included advanced features taken from
  UNIX
• The early OS for microcomputers were based on
  users typing in commands from the keyboard
• Doug Engelbart from SRI invented the Graphical
  User Interface (GUI) with windows, icons, menus,
  and mouse.

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History of Operating Systems

• Steve Jobs saw the value of GUI in a PC and
  developed the Apple computer with GUI (Apple
  Macintosh) in his garage.
• He is also the co-founder of Pixar which has
  created very successful animated films Toy Story
  A Bug's Life Toy Story 2 Finding Nemo
  Monsters.

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Yet another Famous Remarks!

• "640K ought to be enough for anybody."
• Bill Gates, 1981

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History of Operating Systems

• Microsoft developed a GUI-based system called
  Windows which originally ran on top of MS-DOS
  (just as a GUI to DOS)
• Windows 95 and 98 were real GUI based operating
  systems still based on 16 bit Intel assembly
  language
• Windows NT is 32-bit rewrite from scratch version
  of Windows 98.
• Windows 2000 (Windows NT version 5.0), Windows Me.

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History of Computinghttp//www.computerhistory.or
g/

• Hewlett Packard was founded in 1939 by  David
  Packard and Bill Hewlett,
• Their first product, the HP 200A Audio Oscillator
  
• Walt Disney Pictures ordered eight of the 200B
  model to use during the creation of the movie
  Fantasia.

23
History of Computing http//www.computerhistory.o
rg/

• Computer wars
• Germany vs Britain

Alan Turing The bombe
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Overview of Operating Systems

• Introduction
• Operating System Components
• Machine Hardware
• Types of Operating Systems
• Brief Introduction of OS Development focusing
  on Linux (because were already familiar with
  Windows
• Linux vs Windows
• The implications of of Linux in education

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Components of an Operating System

• Operating system part of the computing system
  that manages all of the hardware and all of the
  software
• Controls every file, device, section of main
  memory every nanosecond of processing time
• Memory manager
• Processor manager
• Device manager
• File manager

Operating system consists of
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Subsystems Must Work With Each Other
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Tasks Performed by Each Subsystem

1. Monitor its resources continuously
2. Enforce the policies that determine who gets
   what, when and how much
3. Allocate the resource when appropriate
4. Deallocate the resource (reclaim it) when
   appropriate

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Machine Hardware

• Memory chips
• Input/output devices (monitor, keyboard, printer)
• Storage devices (disks, magnetic tape, card
  readers, drums)
• Central Processing Unit (Arithmetic Logic Unit,
  registers, internal control, bus control)

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Windows XP
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Windows Vista

• Win release after XP (Oct 01 2006)
• Desktop only release
• Originally 2004, now 2006
• WinFS (NTFS add-on) OUT
• Avalon 3D GUI layer, XML-based
• Based on .NET APIs WinFX
• Digital Rights Restrictions

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Windows Vista
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MacOS X (Refer to Introduction to MAC OS
downloadable from http//zaipul.wikispaces.com)
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Introduction to Linux
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What we will cover

• Why Linux?
• What is Linux?
• Myths of Linux
• Example GUIs app's
• Summary

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Origins of Linux

• Began as student Project by Linus Torvalds
• Opened up to the world, now backed
• by big business
• Scientific cooperation model
• Open source implications
• Better security, anyone can improve,
• open to all, improved competition, cheaper,
  faster
• Matured over 14 years
• WinXP (3-12 years),
• Solaris 2 (15yrs),
• MAC OS (26 years)

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Linux kernel

• Linus Torvalds in 1991
• Based on Minix kernel
• Linux kernel works with GNU components
• Allow commercial redistribution (GPLv2)

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GNU Project (GNUs Not Unix)

• Linux truly began from the inspiration of a
  brilliant man Richard Stallman in 1983.
• To develop Unix-like OS composed entirely of free
  software (GNU GPLv1)

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What is Linux ?

• UNIX-like operating system
• Comprised
• System utilities
• Libraries
• From GNU Project
• Sometimes called GNU Linux
• Supported by IBM, Sun, Novell, Microsoft,

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What is Linux?

• Kernel
• cmds/libs
• apps
• installer a
  DISTRO

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Well-known distros

• Slackware
• Debian
• Redhat, Fedora
• SuSE (drived from Slackware)
• Ubuntu (drived from Debian)
• Knoppix
• Linspire (drived from Debian)

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Distros

• Business
• Embedded
• Webserver
• Home Desktop!

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Why Choose Linux?

• Stability . Since Linux is based on the stable
  UNIX operating system, it inherits that stability
  and reliability. Our Linux servers have uptimes
  in the MONTHS.
• Linux is open-source, which means the source code
  is readily available to anyone who wants it.
  Since the source code available, thousands of
  developers all over the world are able to
  contribute and improve Linux. As a result,
  security patches and new drivers come out
  quickly, sometimes in less than a day. This
  insures a very stable operating system and high
  uptime for your network operations.
• Affordability . You can download Linux software
  for free from the Internet at Real Time
  Enterprises local mirror or CDs can be purchased
  from distribution vendors for as little as 40.
• Linux can run on PC-based hardware. This means
  its easy to add disk space or memory. AND, some
  services will run very well on a P1 with 64MB
  RAM, which you probably have collecting dust at
  your office.
• Speed . Many studies have proven that on equal
  hardware, Linux is several times faster than
  Windows NT. In our own experience a Linux
  fileserver running Samba was at least 10 times
  faster than a Windows NT server and the NT server
  had faster, better hardware!
• Linux uses a graphical user interface that is
  similar to other proprietary operating systems.
  (example Microsoft XP or Mac OSX)

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Growth to today

• 1996 KDE desktop environment
• 1997 GNOME
• 1998 Netscape source code, Mozilla Firefox
• 2000 StarOffice by Sun, then OpenOffice.org

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And now and future

• 25 server, 2.8 desktop (IDC, 2004)
• Expected 38 billion in 2008

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Philosophy of Linux

• Free software and open source
• Freedom to use without restrictions
• Freedom to study software and its source code
• Freedom to modifyo redistribute under certain
  conditions
• Interoperability (with other OSs)
• Portability (on various architectures)
• Community
• Commercialization

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Linux distributions (distro)

• To collect separate softwares, including
• Boot loader
• Linux kernel
• GNU libraries and tools
• Command-line shells
• Graphical X Window System
• Desktop environment
• Application software packages

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Sweet Spot Linux Use

• Supercomputer clusters
• Web servers
• Firewalls, routers, caches
• File servers
• Mail servers
• PDA, cell phones
• Embedded real time (gas pumps, Tivo etc)

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Linux Myths

• Zero cost
• Difficult to learn
• Only for servers
• Less secure than Windows
• Invulnerably secure
• Always suitable

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Myths debunked

• Without cost
• A few distros free, most are commercial. Support
  is important
• Difficult to learn
• Linspire is easy for anyone to learn use
• Only for servers
• Linspire well-proven on laptops, desktops
• Less secure than Windows
• Linux has secure alternatives to IE, Outlook, and
  the registry 3 of the buggiest virus
  propagators around. Still should follow good
  security practices
• Always suitable
• Works very well for surfing/email/Word

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Requirements for a Desktop Linux

• Compatible with your data
• Popular applications
• Secure
• Easy to use
• Plays all media
• Paid support
• Reasonably priced
• Easy to install

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Linux vs. Windows
Linux Windows
Linux has different versions, depending on which vendor develops and runs it. Linux vendors include Linspire, Red Hat, SuSE, Ubuntu, Mandriva, Knoppix, Slackware, Caldera, Debian Windows has different versions. It started with Win3.x, Win9x, WinME, WinNT, Win2000, WinXP. It is a proprietary software produced by Microsoft.
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Linux Cost Windows Cost
Linux is cheap or free to run. It can be downloaded from various Linux vendors. Linux may run off a server so numerous computers may have access to the program. Windows is expensive to run. The price to purchase a full version of Windows XP Professional is about USD400. Only one copy of Windows may be used on a computer. Activation with Microsoft is needed.
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Linux Cost Windows Cost
Linux is an open source software. Source codes are freely distributed to the public, of which programmers had reviewed to improve performance, eliminate bugs and strengthen security. Windows is a proprietary closed source software. Codes are not released to the public.
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Linux OS Stability Windows OS Stability
When properly configured, Linux will run until the hardware fails or if the system is shut down. Linux claims that it may continuously run up to more than a year without freezing or shutting down. It is not as prone to bugs and viruses as most are geared towards Windows. It is known to crash easily, and be infected by bugs and viruses.
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Linux Technical Support Windows Technical Support
As source codes are easily accessible, solving technical problems are effective and efficient. Linux users rely on installation guides, or Linux forums to receive advice and suggestions from other users on technical problems. Very few businesses have trained staff to solve Linux bugs. Proprietary software requires technicians to rely on Microsoft for technical information to fix bugs and problems. Numerous businesses have on site technicians that are Microsoft Certified Professionals.
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There is a catch.

• Any modifications made to any programs must be
  released to the public. This is known as
  Copyleft
• According to Richard Stallman, software
  developers have the right to make changes, share
  codes, use and redistribute, but are not bound to
  give away any derived work.

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Linux and Education
The positive and negative implications of Linux
on Education.
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Linux and EducationCost
Problem/Question Possible Solution
Expensive to purchase proprietary software licenses. Linux can be obtained for free or at a low cost.
Expensive to upgrade proprietary software. Software upgrades or modifications to programs are offered to the public at no cost.
Edu. Inst. have a tight technology budget and are limited to the number of licenses they can purchase. As a result, not all systems in a lab will run the same kinds of programs. Linux runs on a server.
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Linux and Education Hardware Requirement
Problem/Question Possible Solution
Due to budget constraint, many schools still run on 486, Pentium I, II, III. This is evident in many inner-city schools where the communities cannot afford to upgrade technology. Expensive to upgrade hardware for proprietary software. They are slow, and incompatible with the new versions of Windows or other current software applications that require more RAM. Linux runs on networked servers and so may continue to use the 486, Pentium I, II, III. The community can also donate their old systems to their neighborhood school. Linux runs on minimal hardware requirements. Linux forums recommend that the minimal system requirements to function with decent performance is Pentium III, 128MB memory, 3Gb hard drive space, and bootable CD drive.
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Linux and EducationSoftware Requirement
Problem/Question Possible Solution
Expensive to purchase proprietary software licenses. Linux can be obtained for free or at a low cost.
Expensive to upgrade proprietary software. Software upgrades or modifications to programs are offered to the public at no cost. Old systems without graphical interface and minimum applications will not be compatible with recent Linux versions.
Edu. Inst. have a tight technology budget and are limited to the number of licenses they can purchase. As a result, not all systems in a lab will run the same kinds of programs. Linux runs on a server and computers can be networked to all run on the same programs.
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Linux and EducationSoftware Applicability
Problem/Question Possible Solution
Many Edu. Inst. had spent millions of dollars in purchasing software licenses. This includes Windows, Microsoft Office and Educational games. If the movement of Linux is successful, the investment of these licenses are non-refundable. There are Linux software programs similar to the function of Windows Microsoft. This includes Open Office, Star Office, KOffice.
In the future, when the student needs to use Windows in the workforce, and not Linux-they would lack the knowledge and training. No Solution
In the future, when the student needs to use Windows in the workforce, and not Linux-they would lack the knowledge and training. Very few game editors publish Linux versions of their games. Schools will have no choice other than to stay with Windows.
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Linux and EducationInstallation and Technical
Support
Problem/Question Possible Solution
As the majority of Edu. Inst. owned computers do not run on Linux, they lack on-site trained and experienced technicians to install and provide technical support. There is already a shortage of technicians hired by the school board due to budget constraint. Design professional-development workshops to train existing and new technicians with Linux, as well as teach teachers so they may educate their students in return. It takes fewer people to manage the Linux machines than Windows machines.
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Linux and EducationTransition Period
Problem/Question Possible Solution
Windows and Linux operating system do not work similarly. Users need to invest time to adapt to the change in OS. Some Windows applications may run on Linux, when an emulator is used. A common emulator is called Wine. Install Windows and Linux on the same computer, which may act as an easier transition for beginners or those who are fans of both OS.