Bab 1 fundamental of os

PREPARED BY: NURBAYA GHAZALI, JTMK, PSP


COURSE ASSESSMENT

I- CONTINOUS ASSESSMENT (PB) = 50%

a) Quiz = min 7 (15%)b) Assignment =min 5 (25%)c) Lab work = min 10 (20%)d) Theory Test = min 2 (40%)

II- FINAL EXAMINATION = 50%

Will be converted to 50%


CHAPTERS IN FUNDAMENTALS OF OPERATING SYSTEM

1.0 INTRODUCTION TO OPERATING SYSTEM2.0 BASIC OPERATING SYSTEM CONCEPT MANAGEMENT

3.0 RESOURCE MANAGEMENT4.0 FILE MANAGEMENT

5.0 WINDOWS OPERATING SYSTEM


CHAPTER 1.0 INTRODUCTION TO OPERATING SYSTEM


INTRODUCTION TO OPERATING SYSTEM (OS)WHAT IS OPERATING SYSTEM ?

a program that acts as an intermediary between a user and the computer hardware

OS IS THE SOUL OF

THE COMPUTER

An operating system, or OS, is a software program that enables the computer hardware to communicate and operate with the computer software. Without a computer operating system, a computer would be useless Operating systems can also be considered to be managers of the resources. Anoperating system determines which computer resources will be utilized for solving whichproblem and the order in which they will be used


Software controlling the overall operation of a multipurpose computer system, including such tasks as memory allocation, input and output distribution, interrupt processing, and job scheduling.

MAIN RESPONSIBILITIES OF OSThree (3) main responsibilities of operating

system :

Perform basic tasks, such as recognizing input from the keyboard, sending output to the display

screen, keeping track of files and directories on

the disk, and controlling peripheral devices such as

disk drives and printers.

Ensure that different programs and users running

at the same time do not interfere with each other.

Provide a software platform on top of which other

programs (i.e., application software) can run.


Computer software can be divided into two main categories :

a) application software :consists of the programs for performing tasks particular on behalf of user .Examples: spreadsheets, database systems, desktop publishing systems, program development software, and games

b) system software : designed to operate the computer hardware and to provide and maintain a platform for running application software. Divided into two categories which are operating system (MS Windows, Linux,Mac)and utilities (eq: antivirus software, clean disk, disk defragment).

COMPUTER SOFTWARE


HISTORY OF OS : GENERATIONS OF COMPUTER

GENERATIONS OF COMPUTER

1st GENERATION 2nd GENERATION

3rd GENERATION

4 th GENERATION

5 th GENERATION


1st GENERATIONS OF COMPUTER : VACUUM TUBES & PLUG BOARDS(1945-1955)

1. Use of vacuum tubes2. Big & Clumsy3. High Electricity Consumption4. Programming in Mechanical Language5. Larger AC were needed6. Lot of electricity failure occurred


2nd GENERATIONS OF COMPUTER : TRANSISTORS & BATCH SYSTEMS, (1955-1965)

1. Transistors were used2. Core Memory was developed3. Faster than First Generation computers4. First Operating System was developed5. Programming was in Machine Language & Assembly Language6. Magnetic tapes & discs were used7. Computers became smaller in size than the First Generation computers8. Computers consumed less heat & consumed less electricity


3 rd GENERATIONS OF COMPUTER : ICs & MULTIPROGRAMMING (1965-1980)

1. Integrated circuits developed2. Power consumption was low3. SSI & MSI Technology was used4. High level languages were used


4 th GENERATIONS OF COMPUTER : PERSONAL COMPUTERS, (1980-Present)

1. LSI & VLSI Technology used2. Development of Portable Computers3. RAID Technology of data storage4. Used in virtual reality, multimedia, simulation5. Computers started in use for Data Communication6. Different types of memories with very high accessing speed & storage capacity


5 th GENERATIONS OF COMPUTER (Present)

1. Used in parallel processing2. Used superconductors3. Used in speech recognition4. Used in intelligent robots5. Used in artificial intelligence



VARIOUS TYPES OF OS STRATEGY

Batch Operating System- This strategy involves reading a series of jobs (called a batch)

into the machine and then executing the programs for each job in the batch. This approach does not allow users to interact with programs while they operate.

Multiprogramming Operating System- The ability to do more than one job is called

multiprogramming. The system separates the memory out into several pieces and lets each one of the pieces be a different job that the computer was running. The ability to do multiprogramming speed the computers up tremendously.

- When one job idled to wait for input or output, the operating system could automatically switch to another job that was ready.

Distributed Operating System- An operating system that manages a group of independent

computers and makes them appear to be a single computer

- Distributed computations are carried out on more than one machine

- When computers in a group work in cooperation, they make a distributed system.


VARIOUS PRODUCT /TYPES OF OS IN TODAY’S MARKET

MICROSOFT WINDOWS

SUN / SOLARIS

LINUX

MAC OS


VERSION S OF WINDOWS OPERATING SYSTEM

WINDOWS 95WINDOWS 98 WINDOWS 2000 WINDOWS ME

WINDOWS XP WINDOWS VISTAWINDOWS 7


DISTRIBUTIONS OF LINUX OPERATING SYSTEM

UBUNTU LINUX SUSE LINUXRED HAT LINUX

DEBIAN LINUXFEDORA LINUX

TURBO LINUX

CENTOS LINUX


MINIMUM REQUIREMENT FOR INSTALLATION OF WINDOWS OPERATING SYSTEM

VISTA BUSINESS EDITION


MINIMUM REQUIREMENT FOR INSTALLATION OF LINUX OPERATING SYSTEM

Processor: Intel: Pentium 1-4 or Xeon; AMD: Duron, Athlon, Athlon XP, Athlon MP, Athlon 64, Sempron or Opteron

256 MB of RAM (512 MB recommended)

500 MB of disk space (800 MB to 2 GB often required when including a basic set of applications)

UBUNTU LINUX

GENERAL REQUIREMENT FOR LINUX


OPEN SOURCE VS CLOSED SOURCE OS

means the source code is available to the end-user. The user can use,change,modify and improve the software, to redistribute it in modified or unmodified forms . Eq: Linux OS

OPEN SOURCE

CLOSED SOURCE

means that the source code is held by the developer, and only they can make any changes or study it. Eq: Windows OS.


MENU-DRIVEN SYSTEM

SHELL PROGRAM

FULLY GRAPHICAL USER INTERFACE

A program that obtains input from a user by displaying a list of options – the menu – from which the user indicates his/her choice. Eq: ATM Machine, automatic washing machine.

Type of user interface item that allows people to interact with programs in more ways than typing that uses windows, icons and menus and which can be manipulated by a mouse such as computers; hand-held devices such as MP3 Players, Portable Media Players or Gaming devices;

The shell is used to issue commands, start processes, control jobs, redirect input and output, and other mundane things that you do on a modern computer. Not only that, the shell is a pretty complete programming language.


NETWORK OPERATING SYSTEM

Coordinate the activities of multiple computers across a network. The network operating system acts as a director to keep the network running smoothly

Operating system that contains components and programs that allow a computer on a network to serve requests from other computer for data and provide access to other resources such as printer and file systems.

Network operating systems typically are used to run computers that act as servers. They provide the capabilities required for network operation.

The two major types of network operating systems are: - Peer-to-Peer - Client/Server

Some of the Network services such as File Sharing, Print sharing, User administration & Backing up data


TERMINOLOGIES IN OS

Cooperative Multitasking: A form of multitasking where it is the responsibility of the currently running task to give up the processor to allow other tasks to run.

A type of multitasking in which the process currently controlling the CPU must offer control to other processes. It is called cooperative because all programs must cooperate for it to work. If one program does not cooperate, it can stop the CPU.

Preemptive multitasking:A method of running more than one program on a computer at a time, in which control of the processor is decided by the operating system, which allocates each program a recurring time segment.

is task in which a computer operating system uses some criteria to decide how long to allocate to any one task before giving another task a turn to use the operating system. The act of taking control of the operating system from one task and giving it to another task is called preempting.

Multithreading:Multi-Threading is the ability of a CPU to execute several threads of execution apparently at the same time. CPUs are very fast at executing instructions. Modern PCs can execute nearly a billion instructions every second. Instead of running the same program for one second, the CPU will run one program for perhaps a few hundred microseconds then switch to another and run it for a short while and so on.


OPERATING SYSTEM STRUCTURE

1) MONOLITHIC SYSTEM

This system considered as “ The big mess” because this structure is no structure actually

The components of monolithic system are unorganized Any module can call any other module without any reservation.

Does not enforce data hiding . Every procedure is visible to every other procedure. It delivered better application performance but extending such a system can be difficult Work because modifying a procedure can introduce bugs in unrelated parts of the system.

Example system : CP/M (Control Program for Microcomputers) & MS-DOS


When a user –mode program calls a system service, the processor traps the call and then switches the calling thread to kernel mode. Completion of system service, switches the thread back to the user mode, by the operating system and allows the caller to continue.

Figure 1: Monolithic Operating System


Figure 2: A simple structuring model for a monolithic system

A main program that invokes the requested service procedure. A set of service procedures that carry out the system calls. A set of utility procedures that help the services procedures.


2) LAYERED SYSTEM

The operating system is divided into a number of layers (levels), each built on top of lower layers.This system had 6 layers.

The Structure of the THE ()operating system


Layer 0 dealt with allocation of the processor, switching between processes when interrupts occurred or timers expired. Layer 0 provided the basic multiprogramming of the CPU.

Layer 1 did the memory management. It allocated space for processes in main memory and on a 512k word drum used for holding parts of processes (pages)for which there was no room in main memory. The layer 1 software took care of making sure pages were brought into memory whenever they were needed.

Layer 2 handled communication between each process and the operator console. Above this layer each process effectively had its own operator console.

Layer 3 took care of managing the I/O devices and buffering the information streams to and from them.

Layer 4 was where the user programs were found. They did not have to worry about process, memory, console, or I/O management.

The system operator process was located in layer 5.

Example system: VAX /VMS, MULTICS, UNIX


3) VIRTUAL MACHINES

The heart of the system, known as the virtual machine monitor, runs on the bare hardware and does the multiprogramming, providing not one, but several virtual machines to the next layer up.

Each virtual machine is identical to the true hardware, each one can run any operating system that will run directly on the hard ware.Different virtual machines can, and usually do, run different operating systems.

Some run one of the descendants of OF/360 for batch processing, while other ones run a single-user, interactive system called CMS (conversational Monitor System) for timesharing users.


Virtual Machine Model System


4) CLIENT-SERVER MODEL

All the kernel does is handle the communication between clients and servers

By splitting the operating system up into parts, each of which only handles one fact of the system, such as file service, process service, Terminal service, or memory service, each part becomes small and manageable.

Another advantage of the client-server model is its adaptability to use in distributed system. If a client communicates with a server by sending it messages, the client need not know whether the message is handled locally in its own machine, or whether it was sent across a network to a server on a remote machine. As far as the client is concerned, the same thing happens in both cases: a request was sent and a reply came back.


The client-server model

A distributed OS


MAJOR SUBSYSTEM IN OS

1) PROCESS MANAGEMENT

A process is a program in execution

A process needs certain resources, including CPU time, memory, files, and I/O devices, to accomplish its task.

A process is an active entity whereas a program is a passive entity.

OS process management activities:- Process creation and deletion.- Process suspension and resumption.- Process synchronization.

- - Process communication.- Process deadlock handling


2) FILE MANAGEMENT

The OS provides a uniform logical view of information storage. (Many different types of physical media.)

A file is a collection of related information defined by its creator. File contents, file formats, file structures, file attributes.

Files are organized into directories.

OS file management activities- File creation and deletion.- Directory creation and deletion.- Support of primitives for manipulating files and directories.- Mapping files onto secondary storage.- File backup on stable (nonvolatile) storage media.


3) MEMORY MANAGEMENT

Memory is a large array of words or bytes, each with its own address.

Memory is a repository of quickly accessible data shared by the CPU and I/O devices.

Main memory is a volatile storage device. It loses its contents in the case of system failure.

OS memory management activities:

- Keep track of which parts of memory are used and by whom.- Decide which processes are to be loaded when memory space becomes available.- Allocate and deallocate memory space as needed.


SYSTEM CALLS

Definition: Provide an interface between Operating System and it’s application program. Generally available as assembly-language instructions. Languages defined to replace assembly language for systems

programming allow system calls to be made directly (e.g., C, C++, Perl)

Types Of System Calls:

1) Process control2) File management3) Device management4) Information maintenance5) Communications


1) PROCESS CONTROL

Create and terminate processes: fork, exit.

Execute processes: exec. Get/set process attributes. Abort, end processes. Wait for time, wait for event, signal

event. Allocate and free memory.

2) FILE MANAGEMENT

Create file, delete file. Open, close. Read, write, reposition. Get/set file attributes. Similar operations for directories.


3) DEVICE MANAGEMENT

Request/release device. Read, write, reposition. Get/set device attributes. Logically attach or detach

devices.4) INFORMATION MAINTENANCE

Get time or date, set time or date. Get system data, set system data. Get process, file or device attributes. Set process, file or device attributes.


5) COMMUNICATION

Create, delete communication connection. Send, receive messages. Transfer status information. Attach or detach remote devices.

Documents

Bab 1 fundamental of os