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WIA2004: Operating Systems

Assoc. Prof. Dr. Mazliza OthmanRoom B-3-20, Block BEmail: mazliza@um.edu.my

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References

Flynn I.M., McHoes, A.M., “Understanding Operating Systems”, 8th Edition, Thomson Course Technology, 2017.

Silberschatz and Galvin, “Operating Systems Concepts”, 6th Edition, John Wiley, 2002.

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History of OS Development

1st-generation computers (1940-1955). 2nd-generation computers (1955-1965). 3rd-generation computers (from mid

1960s). 1970s. 1980s. 1990s. 2000s. 2010s

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The First Computers

Augusta Ada Byron, the world’s first

computer programmer played

a key role in formulating the

notion of programming the Analytical Engine.

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The First Computers

In 1991, the London Science

Museum built the Difference Engine using

Babbage's plans, as shown in this

woodcut. It worked

perfectly.

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The First Computers

Hollerith’s punched-card tabulating machines are

the predecessors of today’s business machines.

Hollerith & the Automated Census Bureau invented an electronic punching device

founded Tabulating Machine Co. which became IBM

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Foundations of Modern Computing

ENIAC, created by Dr. John Mauchly & J.

Presper Eckert, for use in the

war but was not completed in time. It was

mainly used to solve math problems.

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The Stored Program Concept

The computer program, as well as the data, is stored in the computer’s memory.

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The First Generation (1950s)

The first generation of computers used vacuum tubes. Vacuum tubes failed frequently so first generation

computers did not work most of the time.

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Eckert and Mauchly delivered the first UNIVAC to the U.S. Census Bureau in 1951.

UNIVAC gained fame when it predicted Eisenhower as the winner of the 1952 U.S.

presidential election.

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The First Generation

Features of UNIVAC easier to use (than ENIAC) fewer vacuum tubes (more reliable) stored program general-purpose used machine language

IBM 701 IBM 650

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Second Generation (Early1960s)

The transistor heralded the

second generation of computers

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The Second Generation Features and Advancements

still used punch cards used printers, tape storage, & disk storage used high-level programming languages COBOL & FORTRAN introduced

IBM 1401

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The Second Generation

Electronic Recording Machine --Accounting (ERMA)

American Standard Code for Information Interchange (ASCII)

IBM System/360 line of compatible computers instruction set enabled to be used for both

business and science

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The Third Generation (Mid 1960s to Mid 1970s)

Advancements and Milestones used timesharing accessed remotely by terminals used integrated circuits (small, medium, to

large-scale integration) resulting in lower cost

Integrated chips

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The Third Generation More Advancements and Milestones

DEC’s minicomputer, the PDP-8 many different programming languages IBM “unbundled” its systems

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Still More Advancements and Milestones Wide-area networks (WAN) developed ARPANET implemented Internet protocols

(TCPIP) Local area networks (LAN) developed Mainframes (proprietary)/minicomputers

(open architecture)

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The Fourth Generation (1975-1991)

Advancements and Milestones employed very-large-scale integration (VLSI)

developed Intel 4004, first microprocessor Apple Computer founded IBM introduced the Personal Computer (PC) IBM compatibles or clones introduced

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The Fourth GenerationThe first IBM PC was released in 1981. Intel provided the

microprocessor chip and Microsoft Corporation provided the operating system

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The Fourth Generation

Interfaces IntelMotorola

Macintosh PCThe first GUI was developed at Xerox

Corporation’s Palo Alto Research Center (PARC)

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ModuleB

Macintosh was the first commercial

personal computer to offer a user interface

Microsoft’s Windows 98 is a

popular GUI designed for

IBM-compatible microcomputers

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A Fifth Generation?

Experts have forecast that the

hallmark of the fifth generation will be

artificial intelligence (AI), in which

computers exhibit characteristics of human intelligence. AI has been slow in

coming.

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A Fifth Generation?

Technologically, we’re still in the fourth generation, in which engineers

are pushing to see how many transistors they can pack on chip. This

effort alone will bring some of the trappings of AI.

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What is an operating system?

THE boss of a computing system. An operating system (OS manages all

hardware and software. It controls every file, device, section of

main memory and nano-second of processing.

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Hardware Configuration

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Types of Operating Systems

4 categories based on response time and how data is entered into the system: Batch systems, Interactive systems, Real-time systems, and Hybrid systems.

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OS Software

There are 4 managers of an OS: Memory manager Processor manager

Job scheduler Process scheduler

Device manager File manager

Each manager must work harmoniously with other managers.

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Sub-system managers

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Network Manager

The fifth manager for OS with networking capability.

Allows authorized users to share resources.

Responsible for all aspects of network connectivity.

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User Command Interface

The User Command Interface provides a means for users to issue command to the OS.

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Machine Hardware (1)

A computer’s hardware is the physical machine and its electronic components.

Main memory: where data and instructions must reside to be processed.

Input/output (I/O) device: peripheral units such as printers, disk drives, CD drives, thumb drive.

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Machine Hardware (2)

Central processing unit (CPU): the brain of a computer. Controls the operation of the entire

computer system. Consists of circuits (chips) to control the

interpretation and execution of instruction.

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Current OS (1)

The features of current OS are based on users’ needs. Support for multimedia applications Internet and Web access Client/server computing.

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Current OS (2)

The system architecture has been improved in the way components are programmed and organized.

Use of object-oriented design; reorganization of the kernel.

The kernel is the part of the OS that resides in memory at all times.

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Current OS (3)

Another important improvement is the introduction of threads.

A process has 2 characteristics: It requires space in main memory where

it resides during the execution. From time to time, it requires other resources (e.g. data files).

It passes through several states (e.g. running, waiting, ready) from its initial arrival to its completion.

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Current OS (4)

In a modern OS, processes are swapped between main memory and secondary storage during execution. In conventional processes (known as

heavyweight processes), this incurs high overhead because for each swap, all process info must be saved to preserve the process’s integrity.

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Current OS (5)

A thread is a unit smaller than a process; it can be scheduled and executed. The heavyweight process which owns

resources becomes a passive element. The thread becomes the element that

uses the CPU and is scheduled for execution.

Swapping a thread is less time consuming than swapping a process because there is less info to be saved.

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Current OS (6)

Multiprocessing is where two or more CPUs share the same main memory, most I/O devices and the same control program routines.

They service the same job stream and execute distinct processing programs concurrently.

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Current OS (7)

Symmetric multiprocessing allows several CPUs to process multiple jobs at the same time. The CPUs are independent of each other. Each CPU has access to the OS. They share memory and secondary

storage devices.

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Current OS (8) In asymmetric multiprocessing, some OS

functions are assigned to subordinate processors, which take their instructions from the main CPU. E.g. in a system with one processor, all disk

scheduling and program calculations are managed by the CPU.

If a second CPU is added and assigned the responsibility for disk scheduling, then upon request from the main CPU this processor executes its own algorithm to handle requests for disk access.

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Current OS (9)

Cloud Computing changes the role of OS. It allows OS to accommodate remote

access to system resources, and provides increased security for these transactions.

At its roots, the OS still maintains responsibility for managing all local resources and coordinating data transfer to and from the cloud.

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