The Great Symbian

Nursing Board Exam Results December 2010

2011-02-21T05:14:00.000-08:00

Refer the link below:

Nursing Board Exam Results for December 2010

Congrats!

Adobe CS5 Crack

2011-02-21T04:56:00.001-08:00

I found this long ago and haven't able to share it... so... here it is..

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Hotfile Link:
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Adobe Photoshop CS 5 Crack and Instructions

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download the file above... extract read the README file and follow...

Worms 3D

2011-02-21T04:45:00.000-08:00

Download Link: http://www.mediafire.com/?75oy9d9b3o391ch

Text For Free Using Your Facebook Account!!!

2011-02-21T04:41:00.000-08:00

Steps:

1. Log on to your Facebook account.

2. Go to http://apps.facebook.com/chikkalite/

3. Enter your Philippine mobile phone number and click Request button.

4. You will received confirmation code in your Mobile Phone. Enter that in the text field and click Next.

5. You can now use ChikkaLite for Facebook and enjoy unlimited text for free.

DOTA 6.69C Cheat!!!

2010-11-16T20:04:00.000-08:00

change your dota 6.69c map to a modified/cheated map..

CHEATED MAP DOTA 6.69c
download here: http://www.mediafire.com/?p5ioamwoyxpf0ue#1

Activator for normal cheats is -reggie
Activator for menu cheats is -garenamaster

NOTE: kapag mag type kayo ng -reggie
makikita yun ng allies nyo kaya wag nyo i chat via allies
i chat nyo via OBSERVER para walang makabasa sa na type nyo

working po ito sa GG try nyo!

Normal Cheats:
-gold #
-lumber #
-int #
-agi #
-str #
-lvl #
-xp #
-hp #
-mp #
-ms #
-debuff (Removes buff from selected unit)
-lock (locks the trade system)
-unlock (Unlocks it)
-charges# ### (First # slot 2nd charges)
-additem # (max is about 90)
-invul
-vul
-kill
-mana (Mana stays at 100%)
-invis (makes unit invisible)
-vis (visible)
-pathoff (walkthrough walls)
-pathon (normal)
-setcolor (red/blue/teal/purple/yellow/orange/green/pink/gray/lb/dg/brown)
-owner (red/blue/teal/purple/yellow/orange/green/pink/gray/lb/dg/brown)
-nocd (no cooldown)
-cdon (cooldown on)
-bindup/down/left/right (IE: -bindup -kill would make it so that when you hit up it kills whatever s selected)
-clearkeys (Clears bindings)
-showkeys (Shows bindings)
-mh (Dispalys map, no server splits, hopefully)
-setname
-size #
-food #
-heal
-copy #
-fast (Hit esc when training units)
-bfast (Hit esc on building structure)
-ufast (Research is instant)(To disable one of these commands add -no to it like -noufast)
-shareall
-share ##
-unshare ##
-ally ##
-unally ##
-soff (share off)
-spawn #### (List)
-ground ####
-add ####
-remove #### (removes the ability)
-g ## #### (gold)
-l ## #### (lumber)
-f ## #### (food)
-spa ## #### (Spawn unit)
-sn ## (setname)
-sc ## (red/blue/teal/purple/yellow/orange/green/pink/gray/lb/dg/brown)
-dead (Sets units animation to dead)
-birth (Sets building to being built)
-attack (Sets unit to attack)
-stand (Sets unit to stand)
-hear (You can see what everyone is saying)
-nohear (back to normal)
-noreplay
-kick ##
-tele (sets patrol to teleport)
-note (sets it back to normal)
-reg (Right-click two spots and a region will be made)
-time ## (Sets time to that hour)
-float ### ### (first #'s is height 2nd are speed)
-stop (Disable unit commands)
-resume (Enables them)
-area #### #### (First #'s are size 2nd Rawcode, then click where you want it)
-autoh ### (Autoheals by precentage)(A little buggy)
-disable (Disable -reg)
-list# (1-8 )
-cheaton ## (Turns cheats on for player specified)
-cheatoff ## (Turns cheats off for player specified)
-unit #### (Spawns specified unit at issued location)
-nounit (Disables -unit)
-act (Changes activator to whatever specifed, needs a - at the beginning)
-unitid (Shows the unit's rawcode)
-itemid (Shows the unit's item rawcode in first slot)
-destid (Shows rawcode of destructable in Reg)
-destroy (Removes selected units)
-revive (Revives dead hero and spawns at selected unit)
-addhp (Adds hp to any unit, needs to be divisable by 50)
-colors (Displays player numbers by color)
-say###### (# = hex code only 0-9 and A-F will work)(After the hex just put the text you want displayed)

download here: http://www.mediafire.com/?p5ioamwoyxpf0ue#1

src: www.symbianize.com

SMART FREE INTERNET IN PC

2010-11-05T03:06:00.000-07:00

Requirements:

1.Smart Broadband Kit or Any openlined modem

2.Mozzila FireFox Browser

3.Smart Buddy Sim With 1 Extra peso load

Steps:
STEP 1: Configure your modem.

STEP 2: Add a profile.

STEP 3: Add these settings.

STEP 4: Set as default.

STEP 5: Connect your modem.

STEP 6: Open Mozilla>Tools>Options

STEP 7: Change the network settings.

STEP 8: You can now browse your favorite website.

Download Test: Using IDM: http://www.mediafire.com/?pyflo4e91rw3xu6

ALTERNATE PARENT PROXY:

10.102.61.222

10.102.61.230

10.102.61.232

10.102.61.238

10.102.61.239

10.102.61.250

202.57.96.1

202.57.96.2

202.57.96.3

202.57.96.4

202.57.96.8

202.57.96.12

121.1.3.111

121.1.3.121

121.1.3.115

121.1.3.148

121.1.3.149

121.1.3.150

121.1.3.168

121.1.3.169

121.1.3.172

121.1.3.194

121.1.3.200

208.67.222.220

208.67.222.222

208.67.222.225

202.57.67.31

202.57.67.32

202.57.67.38

202.57.67.45

202.57.67.48

202.57.67.50

203.172.28.130

203.172.28.133

203.172.28.136

203.172.28.138

203.172.28.143

67.225.137.220

67.225.137.222

67.225.137.242

67.225.137.229

203.84.191.216

203.84.191.215

203.84.191.216

203.84.191.215

PORT: 80 OR 8080

source:www.symbianize.com

ULTRASURF HACK FOR FREE INTERNET

2010-11-05T02:58:00.000-07:00

Instruction:

1. Download Ultrasurf form this link: http://ultrareach.net/downloads/ultrasurf/u1001.zip

2. Extract it

3. Open Ultrasurf

-Click Option

-Click Proxy Settings

-Select Manual Proxy Settings. Then input 10.102.61.46:8080 or 10.102.61.238:80

4. Click OK then OK

5. After that, wait for it to connect.

[CONNECTING]

[CONNECTED]

6. Edit your Browser's proxy settings

-Firefox-

-Click Tools > Options...

Click Advanced > Network > Settings...

-Then Follow this format

Also working for Globe, use the following parent proxies...

202.149.67.82 : 8080

118.97.234.253 : 8080

119.252.162.120 : 8080

202.51.107.34 : 8080

222.124.213.118 : 8080

210.23.77.200 : 8080

125.162.242.160 : 8080

201.18.15.11 : 8080

source:www.symbianize.com

ProXPN Configurator and Proxy Provider w/ Oct 28 update

2010-10-30T05:22:00.000-07:00

Features:

Works in offline mode

Provides Random Working Proxy and Untested Anonymous Proxies

Now with GLITCH Patching System

Faster and Easier ProXPN.ovpn Proxy Configuration

New Features:

Allows proxy configuration during proxpn start up and on run

Now valid on some ProXPN based tunneling applications

New sets of proxies. All the old proxies are deleted.

Instructions:

apply the patch [Patch(October-28-2010).exe] before running GLITCHpcapp.exe

Controls:

Download link:

http://www.mediafire.com/file/g14xl2px1dsx945/GLITCHpcapp.rar

How to Crack RS, MU,HF, DF etc. Premium Accounts by EliteCrackers

2010-10-30T05:15:00.000-07:00

This simple tutorial was released by world wide web of EC for newbies to cracking accounts and passwords. Full credits goes to him. Okay lets start...

Whats needed:
i)Apex
Get it here: EliteCrackers_Apex-.rar

ii)To crack account you need Combo List

Get it here: EliteCrackers Combo List

iii)Good Proxy List

Get it here: EliteCrackers Proxy List

Instructions:

1. Download and extract EliteCrackers_Apex-.rar.This includes the most common OCX files needed.

2.Register the OCX files

1. For Windows Vista & 7
1.1 First copy ocx files in system32 folder or sysWOW64
1.2 Open Start, go to Accesories and run Command Line Interface as administrator.
1.3Then type

regsvr32 \Windows\System32\RICHTx22.OCX

2. ForWindows Xp
2.1 First copy ocx files in system32 folder

2.2 Open Start, click Run, type CMD and click open. The command prompt should pop-up.

2.3 Then type

cd C:\

cd Windows

cd System32

regsvr32 blabla.ocx

if there is still missing OCX you can download it here:http://ocxdump.com/

3)Open Apex

4)Now load the Combo List

5)Load Proxy List

6)Go to the Pass Option (see image below)

7)Now go to Site Settings and select the upload site that you want.

8)Then click the Start button. Happy Cracking!

All Software Keys and Cracks from 2007 to 2010

2010-10-24T02:27:00.001-07:00

There are around 3million software's which have complete access to all of the keys and cracks with around 2000 pages in word and these are completely free for all of you. The uploaded rar file here consists of all the keys of software and games which are released from 2007 to 2010.

Download here:

http://www.mediafire.com/file/bexnppinnu106zw/all%20keys.rar source: www.coolpctips.com

Portable Online TV Player for PC

2010-10-24T02:22:00.000-07:00

May option po diyan para maging fullscreen,
itapat lang ang mouse sa bandang baba ng video at makikita po ninyo ang sign para
sa fullscreen then click.escape naman para bumalik sa default.

download link:(14.5mb rar file)

http://www.4shared.com/file/pQbt27J3/portable_online_tv.html

As of now 2 channels pa lang po ang nakalagay sa player na yan
Under maintenance pa kasi yong ibang mga channels.

SMARTBRO lang gamit ko pero tuloy tuloy halos walang bufferring.

Update ko na lang po ung ibang mga channels pag may time ako.
ENJOY!!!

source:www.gsmsandwich.com.ph

High-School of the Dead

2010-09-13T22:01:00.000-07:00

Title : Gakuen Mokushiroku HIGHSCHOOL OF THE DEAD
Japanese Title : 学園黙示録 HIGHSCHOOL OF THE DEAD
Official Site : http://www.geneonuniversal.jp/rondorobe/anime/hotd/
Category : -
Total Episodes : -
Genres : Action, Bishojo, Horror
Year Published : 2010
Release Date : 2010-07-05
Broadcaster : AT-X (Mon 11:30)
Studio : -
US Distribution : -

The world is over taken with a very deadly disease that turns humans into zombies. In Japan, several students of Fujimi High School, and the school nurse, band together to survive the present apocalypse. The story follows Takashi Komuro, one of the students who survived in the initial outbreak.

CLICK HERE HOW TO SPEEDUP DOWNLOAD SPEED
Episode 01 : Mediafire | Megaupload
Episode 02 : Mediafire | Megaupload
Episode 03 : Mediafire | Megaupload
Episode 04 : Mediafire | Megaupload
Episode 05 : Mediafire | Megaupload
Episode 06 : Mediafire | Megaupload
Episode 07 : Mediafire | Megaupload | | DepositFiles
Episode 08 : Mediafire | Megaupload | | DepositFiles
Episode 09 : Mediafire | Megaupload | DepositFiles
Episode 10 : Mediafire | Megaupload | DepositFiles
Episode 11 : Mediafire | Megaupload | FileServe

Naruto Shippuden

2010-09-13T21:50:00.000-07:00

Title : Naruto Shippuden

Japanese Title : NARUTO-ナルト- 疾風伝

Official Site : http://www.tv-tokyo.co.jp/anime/naruto/sippuuden/

Category : TV

Total Episodes : -

Genres : Action, Adventure, Comedy

Year Published : 2007

Studio : -

US Distribution : -

The second incarnation of the very popular NARUTO anime. This anime will feature Part II of the manga storyline which takes place two years after the events at the end of the Sasuke Retrieval arc.

The story revolves mainly around Naruto Uzumaki`s and Sakura Haruno`s new adventures and their search for Sasuke Uchiha after he left Konoha-gakure (Konoha Village) to gain Orochimaru`s power. The plot also shows a more active Akatsuki in their quest for obtaining all the tailed beasts.

After his failed attempt to retrieve Sasuke, Naruto learns that circumstances have granted him slightly less than three years to prepare for a confrontation with Orochimaru, who has to wait that much time before he can transfer into Sasuke`s body. Naruto also must prepare for his eventual confrontation with Akatsuki, who are after the demon sealed within him. To prepare, Naruto leaves the village and undergoes intensive training under Jiraiya. At the same time, Sakura becomes Tsunade`s apprentice, and Sasuke trains under Orochimaru. Thus, all three members of the original Team 7 are now training under one of the Legendary Sannin.

ProXPN Configurator and Proxy Provider

2010-09-09T03:45:00.000-07:00

This application is done to help those who use free browsing tricks (specially those who use ProXPN Tunneling Software). It is advised that you have studied how to use proxpn before using this software, you can refer to www.symbianize.com and www.pinoyden.com for further infos about its usage.

Features

Works in offline mode
Provides Random Working Proxy and Untested Anonymous Proxies
Now with GLITCH Patching System
Faster and Easier ProXPN.ovpn Proxy Configuration

Controls

Simplified PROXPN Proxy Changer

2010-09-09T03:37:00.000-07:00

Download here:

http://www.mediafire.com/file/l0ekwgw8sn1tked/XPNSetting.rar

source:www.symbianize.com

JAVA EXCEPTIONS

2010-05-14T00:07:00.000-07:00

Research 10 Java Exceptions.

1. ArrayIndexOutOfBoundsException
2. ArrayListException
3. NumberFormatException
4. IOException
5. FileNotFoundException
6. ArrayOutOfBoundsException
7. FontFormatException
8. TooManyListenersException
9. NegativeArraySizeException
10. InstantiationException

INHERITANCE, POLYMORPHISM, INTERFACE

2010-04-22T01:54:00.000-07:00

INHERITANCE

–As the name inheritance suggests an object is able to inherit characteristics from another object. In more concrete terms, an object is able to pass on its state and behaviors to its children. For inheritance to work the objects need to have characteristics in common with each other.

In Java, all classes, including the classes that make up the Java API, are subclassed from the Object superclass.

● Superclass

– Any class above a specific class in the class hierarchy.

● Subclass

– Any class below a specific class in the class hierarchy.

● Benefits of Inheritance in OOP : Reusability
– Once a behavior (method) is defined in a superclass, that behavior is automatically inherited by all subclasses.

– Thus, you can encode a method only once and they can be used by all subclasses.

– A subclass only needs to implement the differences between itself and the parent.

● Overriding Methods
– If for some reason a derived class needs to have a different implementation of a certain method from that of the superclass, overriding methods could prove to be very useful.

– A subclass can override a method defined in its superclass by providing a new implementation for that method.

●Final Classes
– Classes that cannot be extended
– To declare final classes,

we write,

public final ClassName{
. . .

}

● Final Methods

– Methods that cannot be overridden

– To declare final methods,

we write,

public final [returnType] [methodName]([parameters])

{

. . .

}

– Static methods are automatically final.

POLYMORPHISM

– The ability of a reference variable to change behavior according to what object it is holding.

– This allows multiple objects of different subclasses to be treated as objects of a single superclass, while automatically selecting the proper methods to apply to a particular object based on the subclass it belongs to.

● Abstract Class

– a class that cannot be instantiated.

– often appears at the top of an object-oriented programming class hierarchy, defining the broad types of actions possible with objects of all subclasses of the class.

INTERFACE

– is a special kind of block containing method signatures (and possibly constants) only.

– defines the signatures of a set of methods, without the body.

– defines a standard and public way of specifying the behavior of classes.

– allows classes, regardless of their locations in the class hierarchy, to implement common behaviors.

– NOTE: interfaces exhibit polymorphism as well, since program may call an interface method, and the proper version of that method will be executed depending on the type of object passed to the interface method call.

WORKING WITH THE JAVA CLASS

2010-04-19T02:03:00.000-07:00

· OBJECT-ORIENTED PROGRAMMING

- is a method of implementation in which programs are organized as cooperative collections of objects, each of which represents an instance of some class, and whose classes are all members of one or more hierarchy of classes united via inheritance relationships.

OOP (Object-oriented programming) = encapsulated state + inheritance

Object-Oriented Design
– Focuses on object and classes based on real world scenarios
– Emphasizes state, behavior and interaction of objects
– Advantages:

·Faster development

·Increased quality

·Easier maintenance

·Enhanced modifiability

·Increase software reuse

· ENCAPSULATION
- Combine the data and the operations
- Enclosing of both variables and functions
- Keep details of the data and operations from the users of the ADT
- Once you have created an ADT for complex numbers, say Complex, you can use it in the same way like well-known data types such as integers.
– Principle of hiding design or implementation information not relevant
to the current object

· OBJECT
- An entity with unique identity that encapsulate state
- state can be accessed in a controlled way from outside
- The access is provided by means of methods (procedures that can directly access the internal state)

· CLASS
- A specification of objects in an incremental way
- By inheriting from other classes
- And specifying how its objects (instances) differ from the objects of the inherited classes

·CLASS VARIABLE
– Behave like a global variable
– Can be accessed by all instances of the class

·CLASS INSTANTIATION
The process of creating objects from a class is called instantiation. So an object is always an instance of a class which represents the blueprint.
The object is constructed using the class and must be created before being used in a program.
Objects are manipulated through object references (also called reference values or simply references)

Creating objects in Java usually follow these steps:

1- Declaration of a reference variable of the appropriate class which will store a reference to the object.
For example:

//declaring my car
Car myCar;

// declaring my father's car
Car myFatherCar ;

Or combined if they belong to the same appropriate class, separated by a comma:

//declaring my car and my father's car
Car myCar, myFatherCar ;

2- Creating an object
This involves using the new operator and calling a constructor to create an instance of the class.
The new operator returns a reference to a new instance of the Car class.
The reference can be assigned to a reference variable of the appropriate class, here: myCar and myFatherCar.

// instantiating myCar from the class Car,
//having the String "black" as parameter value.
myCar = new Car("black");

// instantiating myFatherCar from the class Car
//having the String "blue" as parameter value.
myFatherCar = new Car("blue");

Each object has a unique identity and has its own copy of the fields declared in the class.

The purpose of calling the constructor on the right side of the new operator is to initialize the newly created object.

The declaration and initialization can be combined:

// declaring and instantiating myCar from the class Car,
//having the String "black" as parameter value.
Car myCar = new Car("black");

// declaring and instantiating myFatherCar from the class Car
//having the String "blue" as parameter value.
Car myFatherCar = new Car("blue");

·METHOD
– Describes the behavior of an object
– Also called a function or a procedure
– Student registration system example

· METHOD DECLARATION

To declare methods we write,
(*) {
*
}
– where,
● can carry a number of different modifiers
● can be any data type (including void)
● can be any valid identifier
● ::= [,]

· STATIC METHOD

public class StudentRecord {
private static int studentCount;
public static int getStudentCount(){
return studentCount;
}
}
– where,
· public- means that the method can be called from objects outside the class
· static-means that the method is static and should be called by typing,
[ClassName].[methodName]. For example, in this case, we call the method
StudentRecord.getStudentCount()
· int- is the return type of the method. This means that the method should return a
value of type int
· getStudentCount- the name of the method
· ()- this means that our method does not have any parameters

· PARAMETER PASSING

- Pass by Value refers to passing a constant or a variable
holding a primitive data type to a method, and

- Pass by Reference refers to passing an object
variable to a method. In both cases a copy of the variable is passed to the method.

JAVA PROGRAMMING

2010-04-14T01:31:00.000-07:00

A. PRIMITIVE DATA TYPES
- Integral Data Types (byte, short, int long)
- Floating Point (float, double)
- Characters (char, string)
- Boolean (true, false)

B. VARIABLES
A variable is an item of data used to store state of objects.

1. Declaring and Initializing Variables
To declare a variable is as follows,
[=initial value];

2. Outputting Variable Data
In order to output the value of a certain variable, we can use the following commands,
System.out.println()
System.out.print()

C. OPERATORS

1 Arithmetic operators
+, *, /, %, -

2 Increment and Decrement operators
++, --

3 Relational operators
Relational operators compare two values and determines the relationship between those
values. The output of evaluation are the boolean values true or false.
>, >=, <, <=, ==, != 4 Logical operators
Logical operators have one or two boolean operands that yield a boolean result. There
are six logical operators: && (logical AND), & (boolean logical AND), (logical OR),
(boolean logical inclusive OR), ^ (boolean logical exclusive OR), and ! (logical NOT).

D. GETTING INPUT FROM THE KEYBOARD

1. Using buffered reader
·Add this at the top of your code:

import java.io.*;

·Add this statement:

BufferedReader dataIn = new BufferedReader(
new InputStreamReader( System.in) );

· Declare a temporary String variable to get the input, and invoke the readLine()
method to get input from the keyboard. You have to type it inside a try-catch block.

try{
String temp = dataIn.readLine();
}
catch( IOException e ){
System.out.println(“Error in getting input”);
}

2. Using JOptionPane

import javax.swing.JOptionPane;
indicates that we want to import the class JOptionPane from the javax.swing package.
We can also write this as,
import javax.swing.*;
The statement,
name = JOptionPane.showInputDialog("Please enter your name");
creates a JOptionPane input dialog, which will display a dialog with a message, a
textfield and an OK button as shown in the figure. This returns a String which we will
save in the name variable.

E. CONTROL STRUCTURES

1. Decision Control Structures
Decision control structures are Java statements that allows us to select and execute
specific blocks of code while skipping other sections.

· if statement
if( boolean_expression )
statement;

· if-else statement
if( boolean_expression )
statement;
else
statement;

· if-else-if statement
if( boolean_expression1 )
statement1;
else if( boolean_expression2 )
statement2;
else
statement3;

· switch statement
switch( switch_expression ){
case case_selector1:
statement1; //
statement2; //block 1
. . .
//
break;
case case_selector2:
statement1; //
statement2; //block 2
. . .
//
break;
. . .
default:
statement1; //
statement2; //block n
. . .
//
break;
}

2. Repetition Control Structures
Repetition control structures are Java statements that allows us to execute specific
blocks of code a number of times. There are three types of repetition control structures,
the while, do-while and for loops.

·while loop

The while statement has the form,
while( boolean_expression ){
statement1;
statement2;
. . .
}

· do-while loop
The do-while statement has the form,
do{
statement1;
statement2;
. . .
}while( boolean_expression );

· for loop
The for loop has the form,
for (InitializationExpression; LoopCondition; StepExpression){
statement1;
statement2;
. . .
}

F. Java Arrays

1. Declaring Arrays

Arrays must be declared like all variables. When declaring an array, you list the data
type, followed by a set of square brackets[], followed by the identifier name. For
example,
int []ages;
or you can place the brackets after the identifier. For example,
int ages[];
After declaring, we must create the array and specify its length with a constructor
statement. This process in Java is called instantiation (the Java word for creates). In
order to instantiate an object, we need to use a constructor for this. We will cover more
about instantiating objects and constructors later. Take note, that the size of an array
cannot be changed once you've initialized it. For example,
//declaration
int ages[];
//instantiate object
ages = new int[100];
or, can also be written as,
//declare and instantiate
object
int ages[] = new
int[100];

2. Accessing an array element
To access an array element, or a part of the array, you use a number called an index or
a subscript.

3. Array length
In order to get the number of elements in an array, you can use the length field of an
array. The length field of an array returns the size of the array. It can be used by writing,
arrayName.length

4. Multidimensional Arrays
Multidimensional arrays are implemented as arrays of arrays. Multidimensional arrays
are declared by appending the appropriate number of bracket pairs after the array name.

G. JAVA APPLETS

· Life cycle of an applet
-init()
-start()
-stop()
-destroy()

· drawing strings
drawString();
· drawing ovals
drawOval();
· drawing polygons
drawPolygon();
· drawing rectangles
drawRect();
· drawing lines
drawLine();
· changing font color, size, type, and styles

I. FILE HANDLING

· Reading inputs from a text file

· Writing outputs in a text file

2. INTRODUCTION TO JAVA PROGRAMMING

2010-04-14T00:17:00.000-07:00

A. A LITTLE BIT OF HISTORY

Java was created in 1991 by James Gosling et al. of Sun Microsystems. Initially called
Oak, in honor of the tree outside Gosling's window, its name was changed to Java
because there was already a language called Oak.
The original motivation for Java was the need for platform independent language that
could be embedded in various consumer electronic products like toasters and
refrigerators. One of the first projects developed using Java was a personal hand-held
remote control named Star 7.
At about the same time, the World Wide Web and the Internet were gaining popularity.
Gosling et. al. realized that Java could be used for Internet programming.

B. WHAT IS JAVA TECHNOLOGY?

1. A programming language
As a programming language, Java can create all kinds of applications that you could
create using any conventional programming language.

2. A development environment
As a development environment, Java technology provides you with a large suite of
tools: a compiler, an interpreter, a documentation generator, a class file packaging tool,
and so on.

3. An application environment
Java technology applications are typically general-purpose programs that run on any
machine where the Java runtime environment (JRE) is installed.

4. A deployment environment
There are two main deployment environments: First, the JRE supplied by the Java 2
Software Development Kit (SDK) contains the complete set of class files for all the Java
technology packages, which includes basic language classes, GUI component classes,
and so on. The other main deployment environment is on your web browser. Most
commercial browsers supply a Java technology interpreter and runtime environment.

C. SOME FEATURES OF JAVA

1. The Java Virtual Machine
The Java Virtual Machine is an imaginary machine that is implemented by emulating
software on a real machine. The JVM provides the hardware platform specifications to
which you compile all Java technology code. This specification enables the Java software
to be platform-independent because the compilation is done for a generic machine
known as the JVM.
A bytecode is a special machine language that can be understood by the Java Virtual
Machine (JVM). The bytecode is independent of any particular computer hardware, so
any computer with a Java interpreter can execute the compiled Java program, no matter
what type of computer the program was compiled on.

2. Garbage Collection
Many programming languages allows a programmer to allocate memory during runtime.
However, after using that allocated memory, there should be a way to deallocate that
memory block in order for other programs to use it again. In C, C++ and other
languages the programmer is responsible for this. This can be difficult at times since
there can be instances wherein the programmers forget to deallocate memory and
therefor result to what we call memory leaks.
In Java, the programmer is freed from the burden of having to deallocate that memory
themselves by having what we call the garbage collection thread. The garbage
collection thread is responsible for freeing any memory that can be freed. This happens
automatically during the lifetime of the Java program.

3. Code Security
Code security is attained in Java through the implementation of its Java Runtime
Environment (JRE). The JRE runs code compiled for a JVM and performs class loading
(through the class loader), code verification (through the bytecode verifier) and finally
code execution.
The Class Loader is responsible for loading all classes needed for the Java program. It
adds security by separating the namespaces for the classes of the local file system from
those that are imported from network sources. This limits any Trojan horse applications
since local classes are always loaded first. After loading all the classes, the memory
layout of the executable is then determined. This adds protection against unauthorized
access to restricted areas of the code since the memory layout is determined during
runtime.
After loading the class and layouting of memory, the bytecode verifier then tests the
format of the code fragments and checks the code fragments for illegal code that can
violate access rights to objects.
After all of these have been done, the code is then finally executed.

D. PHASES OF A JAVA PROGRAM
The following figure describes the process of compiling and executing a Java program.

· The first step in creating a Java program is by writing your programs in a text editor.
Examples of text editors you can use are notepad, vi, emacs, etc. This file is stored in a
disk file with the extension .java.

·After creating and saving your Java program, compile the program by using the Java
Compiler. The output of this process is a file of Java bytecodes with the file extension
.class.

·The .class file is then interpreted by the Java interpreter that converts the bytecodes
into the machine language of the particular computer you are using.

Task

1. Write the program

2. Compile the program

3. Run the program

Tool to use

1. Any text editor

2. Java Compiler

3. Java Interpreter

Output

1. File with .java extension
2. File with .class extension(Java Byte Codes)
3. Program Output

E. DIFFERENCE BETWEEN JAVA APPLICATIONS AND JAVA APPLETS

- Java applets are java programs that run in a web browser, it is dependent on web browsers.

- Java applications are stand alone java programs. It can be run in a console window or a graphical user interface.

F. WHAT MAKES JAVA AN OBJECT ORIENTED LANGUAGE

- Java is considered as an object oriented programming language because it uses "objects" – data structures consisting of datafields and methods together with their interactions – to design applications and computer programs. Java includes features such as data abstraction, encapsulation, modularity, polymorphism, and inheritance.

LINUX (Ubuntu) Installation Guide with Screenshots

2009-09-17T02:41:00.000-07:00

LINUX

INSTALLATION

WITH

SCREENSHOTS

This is a step-by-step installation procedure for Linux, specifically Ubuntu 8.04. This is only for those who are doing this for the first time. And those who have installed any other OS before will feel this really useless. But for the “others” who have not installed any OS, I hope this will be useful. All those who have previous experience in installation please go through this and point out the mistakes. I am trying to explain the installation procedure by which your can use dual booting, i.e. you can use both windows and Linux in the same computer. For that the computer should already have windows installed in it. You can’t install windows after linux and then use linux because Windows doesn’t detect Linux. But there is a procedure to do that too. By using SuperGRUB, you can do that. But I have not used it and knows nothing about how to do it. So its better to leave it at that. I heard its not that difficult. Arrange for a CD/DVD of Ubuntu 8.04 or the latest version available. It is sent for free to home for personal use by Canonical.Search “Ubuntu ShipIt” in Google for more details. Or download the image of Ubuntu 8.04 from net. Again search in Google for image links. I would recommend using torrent for downloading. Write the image to a CD/DVD. Turn on the computer and start the BIOS edit. Usually its DEL,F1,F2,… key to start the BIOS. There change the BOOT device priority and set CD Drive as NO.1. In most computers it will be the default setting. Save and quit BIOS, insert the CD and restart. The black screen with a choice for language appears. Select English or use others only if you are very comfortable with that language. I recommend english.

The computer will now boot from the CD/DVD. Now the black screen below will come. Click on the Install Ubuntu button.

Wait for some time while the Linux Kernel loading box cruises to 100%. Then the real installation procedures.begin. Its a 7 step process.

STEP 1:- The first step is the language selection. As usual select the English option. The click on the forward button to proceed.

STEP 2:- In this step you see a world map with a lots of dot and a question “Where are you”. They are asking for the time zone of your location. You just got to click on the the red dot near your place or on the drop down menu select it. For Indians the only option is Kolkatta GMT+5:30. Proceed FORWARD. STEP 3:- The third step is the keyboard layout. Just click on your keyboard layout. In India we use the USA layout. If yours is different, you just got to select it and type on the box given below and see whether the same key as you press is appearing on the screen. Its another of the silly steps. Again FORWARD. STEP 4:-If you ask me, this is the only difficult step of the whole installation procedure. But its not that difficult. After you do this once, its a piece of cake. Its a bit dangerous step because one mistake and you can lose your complete data in the hard disk. You get an option Guided or Manual. In guided they help you do it, but I would recommend you to take Manual because you get more flexibility here. When you press forward they scan the disk and the partition table comes. This table has the Device partitions, its type, mount point, format option and size used. Linux’s file system is ext3 and windows use fat32 and NTFS. Linux detects all these file systems. But windows doesn’t detect ext3. So for dual use its always good to use ext3 for only one partition in which Linux is installed and to use fat32 for all other partitions. Leave the partition where Windows is installed as such if you wish to facilitate dual boot. You can remove the rest of partitions and create new partitions. Create one partition in ext3 format and set the mount point as ‘/’ backslash. Its better to give around 5 GB for this partition. A swap area is also needed. The size of this should be around double of the size of your RAM. For most computers 1GB swap area would be sufficient. Create that partition, set its type as Swap area. This should be enough. Now press the FORWARD. STEP 5:- This is again another of the simple step. “Who are you”. Give here your name, the login name and password for your account in the computer and a computer name, which is the name of your computer as seen by other computers in your network. Now click on Forward. STEP 6:- Step 6 unfortunately has no screenshots. But again, this too is a very simple step. They ask whether you want to migrate your user settings like user accounts from your existing OS which would be Windows in most cases. I never select this option. But if its needed you can do it.

STEP 7:- “Ready to Install”. The most beautiful step of them all. You see all the selections you have made in the first six method and see an install button. You can verify them, change them if needed by going back. When all changes have been made, press on INSTALL button. This should be it. Now they start the installation procedures. They set up the partitions, format it. Copies the necessary OS files into the / directory or root directory. It should take some time, around 15 min in the computer in which I installed. When it reaches 100% you see this screen given below. ITS NOW TIME FOR CELEBRATIONS. Hang on!! Just a moment before the celebrations. They ask you to restart the machine before that. So click on the Restart now option and wait for restarting. You can remove the CD/DVD this time before booting because CD/DVD drive is

given the first priority. The booting up procedures can be seen now. Unlike in windows where you see a loading windows screen, here you see all the steps that are being done. There is also an option of booting like windows too. The login screen comes now. Login using the username and password given during installation. The linux screen appears. The mind blowing beauty is bound to leave you speechless for a little while. But don’t be so for long. START ENJOYING THE WONDERFUL OS. AND REMEMBER INSTALLATION SHOULD NOT BE TAKEN AS A HARD JOB. ITS QUITE AN INTERESTING JOB. WHENEVER NEW VERSIONS GET RELEASED TRY IT. Debian, Ubuntu, Mandriva, Red Hat, Kubuntu, Mint etc. are some of the mostly used Linux versions. From my limited knowledge I have felt Ubuntu as the most user-friendly linux OS, especially for those who are new to Linux. For programmers and computer students I would recommend Debian. “WELCOME TO THE FREE WORLD”.

Redhat 8.0 Installation Guide with Screenshots

2009-09-17T02:16:00.001-07:00

NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE

1) Red Hat Linux Boot screen: (Image 1.1)

After configuring the system for booting from a CD, the Red Hat Linux Boot screen appears.

At this point, press Enter for the graphical Setup.

Image 1.2: (96KB .gif)

2) Welcome to Red Hat: (Image 1.2)

The "Welcome to Red Hat" screen appears with the option of Hiding the help pane (left side) or viewing the Release Notes.

Select Next when ready.

Image 1.3: (29KB .gif)

3) Language Selection: (Image 1.3)

The Language Selection screen
displays all of the languages available to install Red Hat with.

I chose English here, then Next.

Image 1.4: (26KB .gif)

4) Keyboard Configuration: (Image 1.4)

Keyboard Configuration is next.

Highlight the best match for your particular system. Usually, the default works best.

Select Next when complete.

Image 1.5: (44KB .gif)

5) Mouse Configuration: (Image 1.5)

Mouse Configuration is next.

Again, highlight the best match for your particular system.

Select Next when finished.

Image 1.6: (51KB .gif)

6) Installation type: (Image 1.6)

Selection of a standard installation type is now available.

The options include Personal Desktop, Workstation, Server, or Custom.

For this particular guide, I selected Personal Desktop and then Next.

Image 1.7: (42KB .gif)

7) Partitioning your system: (Image 1.7)

You are now faced with the option of automatically partitioning your system with the default values or selecting a more expert approach of choosing exactly what values each partition will be.

I chose Automatic, then selected Next.

Image 1.8: (41KB .gif)

8) Warning dialog box: (Image 1.8)

If this is a new hard drive or a hard drive that no partitions currently exist, a warning dialog box will appear.

Select Yes to continue.

Image 1.9: (42KB .gif)

9) Automatic Partitioning: (Image 1.9)

Here are the options of deleting all Linux partitions, deleting all partitions, or keep the disk structure as it already is.

If this is a new drive, any options work just fine, but, if you already have partitions defined, as in a Multi-Boot environment, be careful as to which selection and drive volume you choose.

Also, check the Review and modify box at the bottom to retain control over what happens to the hard drive and view the recommended configuration.

Image 1.10: (42KB .gif)

10) New hard drive structure: (Image 1.10)

If you checked the Review and modify box, the new hard drive structure is displayed.

This fits my purposes, so I chose Next to continue.

11) Boot loader options: (Image 2.1)

Boot Loader options are displayed.

If this is the only OS to be installed, I recommend to install a boot loader, such as Grub (the default).

If this is part of a Multi-Boot System, I recommend to not install a boot loader and use a boot floppy, created later on in the install process, instead.

Important: If you chose to NOT install a boot loader and NOT make a boot floppy, your Red Hat installation will NOT work.

Image 2.2: (50KB .gif)

12) Install a boot loader: (Image 2.2)

Please view my Multi-Boot Guide for more information about Boot Floppies.

Image 2.3: (43KB .gif)

13) Network setup: (Image 2.3)

Network setup options are next.

Enter in the required information for your particular setup, here.

I chose the default, DHCP setup, then selected Next.

Image 2.4: (38KB .gif)

14) Firewall setup: (Image 2.4)

Firewall setup is very important!

If this system will be connected directly to the internet, choose High to start out with.

If this system is already behind a hardware firewall or router, choose Medium as a good starting point.

Image 2.5: (47KB .gif)

15) Language Selection: (Image 2.5)

Additional Language options are also available.

Since I understand no other language besides English, the default was fine.

Image 2.6: (88KB .gif)

16) Time Zone Selection: (Image 2.6)

Configure your Time Zone with this display.

Being on the West Coast, Pacific Time was selected here.

Choose what is right for your location and then select Next to continue.

Image 2.7: (42KB .gif)

17) Create a root or administrator password: (Image 2.7)

Another important part of the installation process is to create a root or administrator password and a "normal" user account for everyday tasks.

DO NOT leave your root password as blank or easily guessable.

Image 2.8: (45KB .gif)

18) Add users: (Image 2.8)

After acceptance of your root password, select the Add button to create an additional account for everyday tasks. Do not worry. If at anytime you need to use the root account to change system settings, you can. You will be prompted for the password even if you are logged in as a regular user.

After creating a new account and selecting a "good" password, select the OK button.

Image 2.9: (43KB .gif)

19) Add as many users as you wish: (Image 2.9)

Your display could look something like this.

Add as many users as you wish, then select Next to continue.

Image 2.10: (39KB .gif)

20) Default package configuration: (Image 2.10)

Here, you have the option of accepting the default package configuration, or selecting exactly what applications and services you desire.

If you wish, you can skip this step and select Next as the default option and your system will be configured accordingly.

However, if you desire to add or subtract particular applications, choose the Customize packages to be installed button and select Next.

Image 2.11: (52KB .gif)

21) Selecting exactly what packages: (Image 2.11)

Here you will have the option of selecting exactly what packages and applications you wish to install.

Detailed descriptions about each are also available, after selecting the check box on the left of the category, by selecting the details button.

Upon completing your options, select Next to continue.

22) Installation will now start: (Image 3.1)

Installation will now start after selecting the Next button.

Image 3.2: (31KB .gif)

23) Formatting of the hard drive: (Image 3.2)

Formatting of the hard drive or partitions will begin.

Depending on the size of the hard drive, this may take much time.

Image 3.3: (31KB .gif)

24) Transfer of the install image: (Image 3.3)

Transfer of the install image to the hard drive now takes place.

Again, if you selected many packages, this could take some time.

Image 3.4: (65KB .gif)

25) Installation of all selected packages: (Image 3.4)

Installation of all selected packages and applications are now underway.

Depending on what was selected and system configuration, this could take 15 minutes to over an hour.

Image 3.5: (65KB .gif)

26) Insert the next CD soon: (Image 3.5)

Do not go far, though, as you may be required to insert the next CD soon.

Image 3.6: (27KB .gif)

27) Boot floppy creation: (Image 3.6)

If this is the only OS to be installed, I recommend to install a boot loader previously, such as Grub (the default). This does NOT mean that you should forget about creating a boot floppy, also.

If this is part of a Multi-Boot System, I recommend a boot floppy, created here, and not to use a boot loader.

Important: If you chose to NOT install a boot loader and NOT make a boot floppy, your Red Hat installation will NOT work.

Please view my Multi-Boot Guide for more information about boot floppies.

Image 3.7: (46KB .gif)

28) Graphics card setup: (Image 3.7)

Select your graphics card setup and memory configuration here.

Chose Next after highlighting your selection.

Image 3.8: (43KB .gif)

29) Monitor Setup: (Image 3.8)

Enter the proper values or highlight the model of your display here.

After selecting the configuration for your system, chose Next.

Image 3.9: (38KB .gif)

30) Desktop resolution: (Image 3.9)

Choose your desktop resolution and bit-depth.

Capabilities beyond your card should not be displayed.

Image 3.10: (35KB .gif)

31) Install complete: (Image 3.10)

Installation is completed and the system will reboot after selecting Next.

Image 4.1: (15KB .gif)

32) Grub boot loader: (Image 4.1)

Upon reboot, the Grub (if selected previously in the install process) is displayed with the option of booting your Linux installation.

If you opted for a boot floppy, ensure that your system is configured to boot from "A:" first, then your hard drive, otherwise, your system may skip to your previous OS by default.

Image 4.2: (9KB .gif)

33) Boot Red Hat: (Image 4.2)

Keep in mind, while the OS is loading, Linux is famous for allowing the USER to choose exactly what, how and why everything happens.

This is not Windows.

You will see all kinds of information about the internal workings of your system.

Do not be alarmed. You will come to enjoy that information in due time. :)

Image 4.3: (77KB .gif)

34) Logon: (Image 4.3)

If you opted for a graphical install screen, the user name prompt is displayed.

Image 4.4: (101KB .gif)

35) Gnome Desktop: (Image 4.4)

The Red Hat 8.0 default desktop is now displayed. If you selected KDE and not Gnome, your view will be slightly different.

Remember, anything that you wish to do, you can, including messing with system files.

When in doubt, think twice. :)

Image 4.5: (71KB .gif)

36) BlackViper.com in Mozilla: (Image 4.5)

I had to fire up Mozilla 1.0.1 to ensure my internet connectivity functioned, and it worked great!

Thank you for viewing my install guide and I hope it has helped you gain an insight to what may be required before taking the Red Hat plunge.

Windows XP Installation Guide with Screenshots

2009-09-17T02:14:00.000-07:00

NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE

This procedure demonstrates how to install Windows XP Professional. The procedure to install Windows XP home edition is very similar to the professional edition. Since Windows XP Pro is more advanced operating system, it will be used to demonstrate the installation procedure.

The best way install Windows XP is to do a clean install. It is not difficult to perform a clean installation. Before you perform the installation I recommend that you check Windows XP Compatibility List to ensure that your hardware is supported by XP. If your hardware is not on the compatibility list you can check your hardware manufactures website to download the drivers for Windows XP. Save all the necessary drivers onto floppy disks or CD before you start the installation.

All versions of Windows XP CD are bootable. In order to boot from CD/DVD-ROM you need to set the boot sequence. Look for the boot sequence under your BIOS setup and make sure that the first boot device is set to CD/DVD-ROM. You can then perform the following steps to install Windows XP:

Step 1 - Start your PC and place your Windows XP CD in your CD/DVD-ROM drive. Your PC should automatically detect the CD and you will get a message saying "Press any key to boot from CD". Soon as computer starts booting from the CD your will get the following screen:

Step 2 - At this stage it will ask you to press F6 if you want to install a third party Raid or SCSI driver. If you are using a an IDE Hard Drive then you do not need to press F6. If you are using a SCSI or SATA Hard drive then you must press F6 otherwise Windows will not detect your Hard Drive during the installation. Please make sure you have the Raid drivers on a floppy disk. Normally the drivers are supplied on a CD which you can copy to a floppy disk ready to be installed. If you are not sure how to do this then please read your motherboard manuals for more information.

Step 3 - Press S to Specify that you want to install additional device.

Step 4 - You will be asked to insert the floppy disk with the Raid or SCSI drivers. Press enter after you have inserted the disk.

Step 5 - You will see a list of Raid drivers for your HDD. Select the correct driver for your device and press enter.

Step 6 - You will then get a Windows XP Professional Setup screen. You have the option to do a new Windows install, Repair previous install or quit. Since we are doing a new install we just press Enter to continue.

Next - How to install Windows XP Page 2

Step 7 - You will be presented with the End User Licensing Agreement. Press F8 to accept and continue

Step 8 - This step is very important. Here we will create the partition where Windows will be installed. If you have a brand new unformatted drive you will get a screen similar to below. In our case the drive size is 8190MB. We can choose to install Windows in this drive without creating a partition, hence use the entire size of the drive. If you wish to do this you can just press enter and Windows will automatically partition and format the drive as one large drive.

However for this demonstration I will create two partition. The first partition will be 6000MB (C: drive) and second partition would be 2180MB (E: drive). By creating two partition we can have one which stores Windows and Applications and the other which stores our data. So in the future if anything goes wrong with our Windows install such as virus or spyware we can re-install Windows on C: drive and our data on E: drive will not be touched. Please note you can choose whatever size partition your like. For example if you have 500GB hard drive you can have two partition of 250GB each.

Press C to create a partition.

Step 8 - Windows will show the total size of the hard drive and ask you how much you want to allocate for the partition you are about to create. I will choose 6000MB. You will then get the screen below. Notice it shows C: Partition 1 followed by the size 6000 MB. This indicates the partition has been created. We still have an unpartitioned space of 2189MB. Next heighlight the unpartitioned space by pressing down the arrow key. Then press C to create another partition. You will see the total space available for the new partition. Just choose all the space left over, in our case 2180MB.

Step 9 - Now you will see both partition listed. Partition 1 (C: Drive) 6000MB and Partition 2 (E: Drive) 2180MB. You will also have 8MB of unpartitioned space. Don't worry about that. Just leave it how its is. Windows normally has some unpartitioned space. You might wonder what happened to D: drive. Windows has automatically allocated D: drive to CD/DVD-ROM.

Select Partition 1 (C: Drive) and press Enter.

Step 10 - Choose format the partition using NTFS file system.This is the recommended file system. If the hard drive has been formatted before then you can choose quick NTFS format. We chose NTFS because it offers many security features, supports larger drive size, and bigger size files.

Windows will now start formatting drive C: and start copying setup files as shown on the two images below :

Step 11 - After the setup has completed copying the files the computer will restart. Leave the XP CD in the drive but this time DO NOT press any key when the message "Press any key to boot from CD" is displayed. In few seconds setup will continue. Windows XP Setup wizard will guide you through the setup process of gathering information about your computer.

Step 12 - Choose your region and language.

Step 13 - Type in your name and organization.

Step 14. Enter your product key.

Step 15 - Name the computer, and enter an Administrator password. Don't forget to write down your Administrator password.

Step 16 - Enter the correct date, time and choose your time zone.

Step 17 - For the network setting choose typical and press next.

Step 18 - Choose workgroup or domain name. If you are not a member of a domain then leave the default settings and press next. Windows will restart again and adjust the display.

Next - How to install Windows XP Page 4

Step 19 - Finally Windows will start and present you with a Welcome screen. Click next to continue.

Step 20 - Choose 'help protect my PC by turning on automatic updates now' and press next.

Step 21 - Will this computer connect to the internet directly, or through a network? If you are connected to a router or LAN then choose: 'Yes, this computer will connect through a local area network or home network'. If you have dial up modem choose: 'No, this computer will connect directly to the internet'. Then click Next.

Step 22 - Ready to activate Windows? Choose yes if you wish to active Windows over the internet now. Choose no if you want to activate Windows at a later stage.

Step 23 - Add users that will sign on to this computer and click next.

Step 24 - You will get a Thank you screen to confirm setup is complete. Click finish.

Step 25. Log in, to your PC for the first time.

Step 26 - You now need to check the device manager to confirm that all the drivers has been loaded or if there are any conflicts. From the start menu select Start -> Settings -> Control Panel. Click on the System icon and then from the System Properties window select the Hardware tab, then click on Device Manager.

If there are any yellow exclamation mark "!" next to any of the listed device, it means that no drivers or incorrect drivers has been loaded for that device. In our case we have a Video Controller (VGA card) which has no drivers installed.

Your hardware should come with manufacturer supplied drivers. You need to install these drivers using the automatic setup program provided by the manufacturer or you need to manually install these drivers. If you do not have the drivers, check the manufacturers website to download them.

To install a driver manually use the following procedure:

(a) From the device manager double click on the device containing the exclamation mark.

(b) This would open a device properties window.

(c) Click on the Driver tab.

(d) Click Update Driver button. The Wizard for updating device driver pops up as shown below:

You now get two options. The first option provides an automatic search for the required driver. The second option allows you to specify the location of the driver. If you don't know the location of the driver choose the automatic search which would find the required driver from the manufacturer supplied CD or Floppy disk. Windows would install the required driver and may ask you to restart the system for the changes to take affect. Use this procedure to install drivers for all the devices that contain an exclamation mark. Windows is completely setup when there are no more exclamation marks in the device manager.

Return to Home Page

Windows Vista Installation with Screen Shots

2009-09-17T02:07:00.000-07:00

NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE

This step-by-step guide demonstrates how to install Windows Vista.

The best way to install Windows Vista is to do a clean install. It is not difficult to perform a clean installation. Before you perform the installation I recommend that you check Windows Vista System Requirments list to ensure that your hardware is supported by Vista. If you dont have Windows Vista drivers for all your hardware, it is a good idea to download all the drivers from the hardware manufacturers website and save all the necessary drivers on a CD-R before you start the installation.

Windows Vista DVD is bootable. In order to boot from the DVD you need to set the boot sequence. Look for the boot sequence under your BIOS setup and make sure that the first boot device is set to CD-ROM/DVD-ROM.

Step 1 - Place Windows Vista DVD in your dvd-rom drive and start your PC. Windows Vista will start to boot up and you will get the following progress bar.

Step 2 - The next screen allows you to setup your language, time and currency format, keyboard or input method. Choose your required settings and click next to continue.

Step 3 - The next screen allows you to install or repair Windows Vista. Since we are doing a fresh install we will click on "install now".

Step 4 - You can now type the product key that came with your Windows vista.

Step 5 - If you do not enter the product key you can still proceed with the installation in which case Windows will ask you which version of Vista you have purchased. Windows Vista Home Basic, Home Premium, Ultimate, Business etc. Select the version you have purchased and click next.

Please note, although you can select any version of Windows and proceed to next stage. It is not good idea to select a different version to the one you have purchased becuase you will not be able to activate Windows at a later stage. Windows Vista can detect which version you have purchased once you enter your product key.

Step 6 - Tick "I accept the licence terms" and press next.

Next - How to install Windows Vista Page 2

Step 7 - Choose the type of installation you want to perform. You will notice that upgrade option is disabled as we have booted from the DVD-R. Therefore we can only select Custom (advanced) option which basicly installs a clean copy of Windows from scratch.

Step 8 - Choose where you would like to install Windows Vista. If you have a new upartitioned hard drive you would get your hard drive listed as shown on the image below. If have have an old hard drive with data or other partitions it will show up as logical drives. You can select the drive options (advaced) to format, delete, or create new partions. Because I am using a single new hard drive i will select next to continue. Windows will create a partition and format it using NTFS files system.

Step 9 - Windows starts the installation process and starts copying all the necessary files to your hard drive as shown on the image below. It will go through various stages of the setup and will reboot your system few times. When your PC reboots it attempts to boot from CD as its the first boot device. Do not press any key during the boot prompt so Windows Vista will continue with the installation by booting from your hard drive.

Step 10 - After installation copy process is complete you are presented with the Setup Windows dialogue box as show below. At this stage you need to choose a user name, password and a picture for your user account. The account you create here is the Administrator account which is the main account for your Windows Vista that has all the privilages. Click next continue.

Step 11 - Now you need to choose your computer name and desktop background. Click next to continue.

Step 12 - Choose wether your want to Help protect Windows automatically. Select "Use recommened settings" to continue.

Step 13 - Review your time and date settings. Select your time zone, correct the date and time and click next to continue.

Next screen presents you to select your computers current location. You can choose between home, work, public location. Choose home to continue. You will finally get a "Thank you" screen which confirms the end of the interactive installation process. This is not the end of the setup process. There are still many after installation configuration to be done. Click next to continue.

Next - How to install Windows Vista Page 3

Step 14 - Windows now runs a benchmark type of application which checks the performance of your system. You will see a status bar at bottom which shows the progress. Once the process is complete you will be presented with the logon screen.

Step 15 - Finally you have the logon screen. Just type your password and press enter or click on the arrow to logon to Windows Vista for the first time.

Step 16 - Soon as you logon you will be presented with welcome centre. You can use the welcome centre to configure, customise, and update Windows vista.

Step 17 - Finally you need to check if all your hardware has been detected correctly. You can do so by checking your device manager. To access device manager click Start menu -> Control panel -> System -> Device manager. You will see all your hardware listed as shown below. You need to check if you have any yellow exclamtion marks next to the name of the device similar to "USB 10/100 LAN" on image below. This indicates the driver has not been installed for this device.

At this stage you need to install Windows Vista drivers by double clicking on "USB 10/100 LAN" or your device. The properties dialog box will appear. Click on Reinstall Driver. Then you can choose wether you want to install the driver from the internet (if available) or install manually from a CD or other media

Once you have removed all the yellow exclamtion marks from the device manager your Windows Vista configuration would be fully complete.

Return to Home Page

RESOURCE ALLOCATION GRAPH

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1. Example of Resource Allocation Graph

2. Example of Resource Allocation Graph

Explanation:

· The Resource Allocation Graph (RAG) above is composed of 3 processes and four resources.
· R1 or resource 1 is composed of only one instance
· R2 has 2 instances
· R3 has one instance
· R4 has 3 instances
· P1 requests instance of R1
· P2 is holding an instance of R1
· P2 requests instance of R3
· P3 holds an instance of R3
· P3 requests an instance of R1
· There is deadlock based of the RAG no. 2 because all of the instances of R2 are held by the P1 and P2, then P3 is requesting for instances of R2. R2 cannot give any instances to P3 that is why a deadlock occurred.

3. Example of Resource Allocation Graph

Explanation:

· The Resource Allocation Graph (RAG) above is composed of4 processes and 2 resources.
· R1 and R2 has composed of 2 instances
· P1 requests instance of R1
· P2 is holding an instance of R1
· P3 also holds an instance of R1
· P3 requests an instance of R2
· P4 holds an instance of R2
· P1 also holds an instance of R2
· There is no deadlock.

4. Example of Resource Allocation Graph

Explanation:

· The Resource Allocation Graph (RAG) above is composed of 2 processes and 2 resources.
· P1 holds an instance of R1
· P2 requests an instance of R1
· P1 and P2 may request an instance of R2

5. Example of Resource Allocation Graph

Explanation:

· The RAG above is compose of 2 resources and 2 processes
· P1 holds an instance of R1
· P2 is requesting an instance of R1
· P2 holds an instance of R2
· P1 may request an instance of R2

RESOURCE ALLOCATION GRAPH

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A set of vertices V and a set of edges E.

· V is partitioned into two types:

» P = {P1, P2, …, Pn}, the set consisting of all the processes in the system.

» R = {R1, R2, …, Rm}, the set consisting of all resource types in the system.

· Request Edge – directed edge P1 -> Rj

· Assignment Edge – directed edge Rj -> Pi

RESOURCE ALLOCATION GRAPH

· Process

· Resource Type With 4 Instances

· Pi request instance of Rj

· Pi holding an instance of Rj

How Would You Know If There's a Deadlock Based on the Resource Allocation Graph?

·If graph contains no cycles - no deadlock.

·If graph contains a cycle :

» if only one instance per resource type, then deadlock.

» if several instances per resource type, possibility of deadlock.

DEADLOCK RECOVERY

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Recovery from Deadlock Recovery from Deadlock

 Process Termination:

· Abort all deadlocked processes.

· Abort one process at a time until the deadlock cycle is eliminated.

· In which order should we choose to abort?

- Priority of the process.

- How long process has computed, and how much longer to completion.

- Resources the process has used.

- Resources process needs to complete.

- How many processes will need to be terminated.

- Is process interactive or batch?

 Resource Preemption

· Selecting a victim – minimize cost.

· Rollback – return to some safe state, restart process for that state.

· Starvation – same process may always be picked as victim, include

number of rollback in cost factor.

DEADLOCK DETECTION

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Deadlock Detection: allow the system to enter a deadlock

state and then recover.

· Requires deadlock detection algorithm

· Technique for forcibly preempting resources and/or terminating tasks

1. ) ALLOW SYSTEM TO ENTER DEADLOCK STATE

2. ) DETECTION ALGORITHM

1. Let Work and Finish be vectors of length m and n, respectively

Initialize:

(a) Work = Available

(b) For i = 1,2, …, n, if Allocationi ≠ 0,then

Finish[i] = false;otherwise, Finish[i] = true.

2. Find an index i such that both:

(a) Finish[i] == false

(b) Requesti

≤ Work

If no such i exists, go to step 4.

3. Work = Work + Allocationi

Finish[i] = true

go to step 2.

4. If Finish[i] == false, for some i, 1 ≤ i ≤ n, then the system is in deadlock

state. Moreover, if Finish[i] == false, then Pi

is deadlocked.

Algorithm requires an order of O(m x n2) operations to detect whether

the system is in deadlocked state.

3.) RECOVERY SCHEME

DEADLOCK PREVENTION

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Deadlock Prevention Deadlock Prevention

 - Mutual Exclusion – not required for sharable resources; must hold for nonsharable

resources.

 - Hold and Wait – must guarantee that whenever a process requests a resource, it

does not hold any other resources.

· Require process to request and be allocated all its resources before it begins

execution, or allow process to request resources only when the process has

none.

· Low resource utilization; starvation possible

- No Preemption –

· If a process that is holding some resources requests another resource that

cannot be immediately allocated to it, then all resources currently being held

are released.

· Preempted resources are added to the list of resources for which the process is

waiting.

· Process will be restarted only when it can regain its old resources, as well as

the new ones that it is requesting.

- Circular Wait – impose a total ordering of all resource types, and require that each

process requests resources in an increasing order of enumeration.

Restrain the ways that request can be made.

METHODS FOR HANDLING DEADLOCKS

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Methods for Handling Deadlocks Methods for Handling Deadlocks

- Deadlock Prevention: ensure that the system will never enter

a deadlock state – expensive operations

· Need to monitor all lock acquisitions

· Selectively deny those that might lead to deadlock

- Deadlock Detection: allow the system to enter a deadlock

state and then recover.

· Requires deadlock detection algorithm

· Technique for forcibly preempting resources and/or terminating tasks

- Ignore the problem and pretend that deadlocks never occur

in the system

· Used by most operating systems, including UNIX

DEADLOCK CHARACTERIZATION

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DEADLOCK CHARACTERIZATION

A deadlock can occur if the following four conditions hold

simultaneously:

1. Mutual exclusion: at least one resource must be held in a

nonsharable mode.

2. Hold and wait: a process must be holding at least one

resource and waiting to acquire additional resources held by

other processes.

3. No preemption: resources can’t be preempted.

4. Circular wait: there exists a set {P0, P1, …, Pn} of waiting

processes such that P0

is waiting for a resource that is held by

P1, P1 is waiting for a resource that is held by P2, …, Pn–1 is

waiting for a resource that is held by Pn, and Pn is waiting for a

resource that is held by P0.

MULTIPROCESSOR SCHEDULING

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CPU scheduling more complex when multiple CPUs are available

Homogeneous processors within a multiprocessor

Load sharing

Asymmetric multiprocessing – only one processor accesses the system data structures, alleviating the need for data sharing

REAL-TIME SCHEDULING

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Hard real-time systems – required to complete a critical task within a guaranteed amount of time
Soft real-time computing – requires that critical processes receive priority over less fortunate ones

THREAD SCHEDULING

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THREAD SCHEDULING

Distinction between user-level and kernel-level threads
OS only schedules kernel-level threads. User-level threads are scheduled through a direct or indirect (LWP) mapping
Many-to-one and many-to-many models, thread library schedules user-level threads to run on LWP

Known as process-contention scope (PCS) since scheduling competition is within the process

Kernel thread scheduled onto available CPU is system-contention scope (SCS) – competition among all threads in system
Typically – PCS is priority based. Programmer can set user-level thread priorities

CPU SCHEDULING ALGORITMS

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Scheduling Algorithms

1.First-come, first-served (FCFS) scheduling

2.Shortest-job first (SJF) scheduling

3.Priority scheduling

4.Round-robin scheduling

5.Multilevel queue scheduling

6.Multilevel feedback queue scheduling

- First-come, First-served (FCFS) scheduling is the simplest scheduling algorithm, but it can cause short processes to wait for very long processes.

- Shortest-job-first (SJF) scheduling is provably optimal, providing the shortest average waiting time. Implementing SJF scheduling is difficult because predicting the length of the next CPU burst is difficult. The SJF algorithm is a special case of the general priority-scheduling algorithm, which simply allocates the CPU to the highest-priority process. Both priority and SJF scheduling may suffer from starvation. Aging is a technique to prevent starvation.

- Round-robin (RR) scheduling is more appropriate for a time-shared (interactive) system. RR scheduling allocates the CPU to the first process in the ready queue for q time units, where q is the time quantum. After q time units, if the process has not relinquished the CPU, it is preempted and the process is put at the tail of the ready queue. The major problem is the selection of the time quantum. If the quantum is too large, RR scheduling degenerates to FCFS scheduling; if the quantum is too small, scheduling overhead in the form of context-switch time becomes excessive.

The FCFS algorithm is nonpreemptive, the RR algorithm is preemptive. The SJF and priority algorithms may be either preemptive or nonpreemptive.

Multilevel queue algorithms allow different algorithms to be used for various classes of processes. The most common is a foreground interactive queue which uses RR scheduling, and a background batch queue, which uses FCFS scheduling. Multilevel feedback queues allow processes to move from one queue to another.

Because such a wide variety of scheduling algorithms are available, we need methods to select among them. Analytic methods use mathematical analysis to determine the performance of an algorithm. Simulation methods determine performance by imitating the scheduling algorithm on a “representative” sample of processes, and computing the resulting performance.

Operating Systems supporting threads at the kernel level must schedule threads - not processes - for execution. This is the case with Solaris 2 and Windows 2000 where both systems schedule threads using preemptive priority based on scheduling algorithm including support for real-time threads. The Linux process scheduler also uses a priority-based algorithm with real-time supports as well. The scheduling algorithms for these three operating systems typically favor interactive over batch and CPU-bound processes.systems typically favor interactive over batch and CPU-bound processes.

SUBSTANTIAL INFORMATION ABOUT THREAD OF ATLEAST THREE OS

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WINDOWS XP THREAD

Implements the one-to-one mapping

Each thread contains

- A thread id
- Register set

- Separate user and kernel stacks

- Private data storage area

The register set, stacks, and private storage area are known as the context of the threads

The primary data structures of a thread include:

- ETHREAD (executive thread block)

- KTHREAD (kernel thread block)

- TEB (thread environment block)

LINUX THREADS
- Linux refers to them as tasks rather than threads
- Thread creation is done through clone() system call
- clone() allows a child task to share the address space of the parent task (process)

JAVA THREADS
- Java threads are managed by the JVM

- Java threads may be created by:

Extending Thread class
Implementing the Runnable interface

THREAD LIBRARY

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Thread Library schedules user-level threads to run on LWP
Thread management done by user-level Threads Library
The Thread Library is responsible for scheduling user threads on the available schedulable entities; this makes context switching of threads very fast, as it avoids system calls. However, this increases complexity and the likelihood of priority inversion, as well as suboptimal scheduling without extensive (and expensive) coordination between the userland scheduler and the kernel scheduler.

MULTI-THREADING MODELS

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MANY-TO-ONE MODEL

• Many user-level threads mapped to single kernel thread.

• Used on systems that do not support kernel threads.

ONE-TO-ONE MODEL

• Each user-level thread maps to kernel thread.

• Creating a user thread requires creating the corresponding kernel thread.

• Windows NT/2000, OS/2

MANY-TO-MANY MODEL

• Allows many user level threads to be mapped to many kernel threads.

• Allows the operating system to create a sufficient number of kernel threads.

• Solaris 2 , IRIS, HP-UX

KERNEL THREAD

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• Supported by the Kernel

• Slower to create and manage threads than are user threads

• If a thread performs a blocking system call, then the kernel can schedule another thread in the application for execution.• Multiple threads are able to run in parallel on multiprocessors.

• Examples
- Windows NT/2000
- Solaris 2
- Tru64 UNIX
- BeOS
- Linux

USER THREAD

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• Thread management done by user-level threads library

• Fast to create and manage threads

• If the kernel is single-threaded, then any user-level thread performing a blocking system call

will cause the entire process to block

• No need for kernel intervention

• Drawback : all may run in single process. If one blocks, all block.

• Examples
- POSIX Pthreads
- Mach C-treads
- Solaris UI-threads

BENEFITS OF MULTI-THREADED PROGRAMMING

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Responsiveness

- Can run even if one thread blocked or bus

- Web browser example – one thread per client

Resource Sharing
Economy

- Creating and context switching threads is low cost

- Solaris 2 : creating 30x, context switch 5x slower for procs

Utilization of MP ArchitecturesF Run each thread on different CPU

THREAD

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A thread, also called a lightweight process (LWP), is the basic unit of CPU utilization.

It has its own program counter, a register set, and stack space.

It shares with the pear threads its code section, data section, and OS resources such as open files and signals, collectively called a task.

Single-threaded process has one program counter specifying location of next instexecuteO Process executes instructions sequentially, one at a time, until completion
Multi-threaded process has one program counter per thread

INTERPROCESS COMMUNICATION (IPC)

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• Mechanism for processes to communicate and to synchronize
their actions.

• Message system – processes communicate with each other
without resorting to shared variables.

• IPC facility provides two operations:
– send(message) – message size fixed or variable
– receive(message)

• If P and Q wish to communicate, they need to:
– establish a communication link between them
– exchange messages via send/receive

• Implementation of communication link
– physical (e.g., shared memory, hardware bus)
– logical (e.g., logical properties)

DIRECT COMMUNICATION

• Processes must name each other explicitly:

– Symmetric Addressing
• Send (P, message) – send to process P
• Receive(Q, message) – receive from Q
– Asymmetric Addressing

•send (P, message) – send to process P
•receive(id, message) – rx from any; system sets id = sender

•Primitives:

–send(A, message) – send a message to mailbox A
–receive(A, message) – receive a message from mailbox A

•Properties of Communication Link

–Links established automatically between pairs
–processes must know each others ID
–Exactly one link per pair of communicating processes

•Disadvantage: a process must know the name or ID of the process(es) it wishes to communicate with

INDIRECT COMMUNICATION

• Messages are directed and received from mailboxes(also referred to as ports).

- Each mailbox has a unique id.

- Processes can communicate only if they share a mailbox.

• Properties of communication link

- Link established only if processes share a common mailbox

- A link may be associated with many processes.

- Each pair of processes may share several communicationlinks.

- Link may be unidirectional or bi-directional.

• Operations

- create a new mailbox

- send and receive messages through mailbox

- destroy a mailbox

• Primitives are defined as:

– send a message to mailbox Areceive(A, message)

– receive a message from mailbox A

• Mailbox sharingF P1, P2, and P3 share mailbox A.

- P1, sends; P2 and P3 receive.

- Who gets the message?

• Solutions

- Allow a link to be associated with at most two processes.

- Allow only one process at a time to execute a receiveoperation.

-Allow the system to select arbitrarily the receiver. Sender is notified who the receiver was.

SYNCHRONIZATION

• Message passing may be either blocking or non-blocking.

–Blocking Send: sender blocked until message received by mailbox or process
–Nonblocking Send: sender resumes operation immediately after sending
–Blocking Receive: receiver blocks until a message is available
–Nonblocking Receive: receiver returns immediately with either a valid or null message.

• Blocking is considered synchronous

• Non-blocking is considered asynchronous

• Send and receive primitives may be either blocking or non-blocking.

BUFFERING

• All messaging system require framework to temporarily buffer messages. These queues are implemented in one of three ways:

1.)Zero Capacity – 0 messages
Sender must wait for receiver (rendezvous).

2.) Bounded Capacity – finite length of n messages

Sender must wait if link full.

3.) Unbounded Capacity – infinite lengthSender never waits.

PRODUCER-CONSUMER EXAMPLE

• One process generates data – the producer

• The other process uses it – the consumer

• If directly connected – time coordination

- How would they coordinate the time ??

• One process generates data – the producer

• The other process uses it – the consumer

• If not directly connected – have a buffer

- Buffer must be accessible to both

- Finite Capacity N – Number in use - K

COOPERATING PROCESSES

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•Independent process cannot affect or be affected by the
execution of another process.

•Cooperating process can affect or be affected by the execution of
another process

•Advantages of process cooperation
– Information sharing
– Computation speed-up
– Modularity
– Convenience

OPERATIONS OF PROCESS

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OS should be able to create and delete processes dynamically.

A. PROCESS CREATION

When the OS or a user process decides to create a new process, it can proceed as follows:
- Assign a new process identifier and add its entry to the primary process table.
- Allocate space for the process (program+data) and user stack. The amount of space required can set to default values depending on the process type. If a user process spawns a new process, the parent process can pass these values to the OS.
- Create process control block.
- Set appropriate linkage to a queue (ready) is set.
- Create other necessary data structures (e.g. to store accounting information).
Parent process creates children processes, which, in turn create other processes, forming a tree of processes.
Resource sharing possibilities
- Parent and children share all resources.
- Children share subset of parent’s resources.
- Parent and child share no resources.
Execution possibilities
- Parent and children execute concurrently.
- Parent waits until children terminate.
Address space possibilities
- Child duplicate of parent.
- Child has a program loaded into it.

B. PROCESS TERMINATION

A process terminates when it executes last statement and asks the operating system to delete it by using exit system call. At that time, the child process
- Output data from child to parent (via wait).
- Process’ resources are deallocated by operating system.
Parent may terminate execution of children processes via appropriate system called (e.g. abort). A parent may terminate the execution of one of its children for the following reasons:
- Child has exceeded allocated resources.
- Task assigned to child is no longer required.
- Parent is exiting.
Operating system does not allow child to continue if its parent terminates.
- Cascading termination.

PROCESS SCHEDULING

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A. PROCESS SCHEDULING QUEUES

Job Queue – When a process enters a system, it is put in a job queue.

Ready Queue – set of all processes residing in main memory, ready and waiting to execute are kept in ready queue.

Device Queues – There may be many processes in the system requesting for an I/O. Since only one I/O request can be entertained for a particular device, a process needing an I/O may have to wait. The list of processes waiting for an I/O device is kept in a device queue for that particular device.

An example of a ready queue and various device queues is shown below.

B. SCHEDULERS

A process may migrate between the various queues.
The OS must select, for scheduling purposes, processes from these queues.
Long-term scheduler (or job scheduler) – selects which processes should be brought into the ready queue.
- It is invoked very infrequently (seconds, minutes) Þ (may be slow).
- It controls the degree of multiprogramming.

Short-term scheduler (or CPU scheduler) – selects which process should be executed next and allocates CPU.
- Short-term scheduler is invoked very frequently (milliseconds) Þ(must be fast).

Midterm scheduler selects which partially executed job, which has been swapped out, should be brought into ready queue.

C. CONTEXT SWITCH

When CPU switches to another process, the system must save the state of the old process and load the saved state for the new process - this is called context switch.

The time it takes is dependent on hardware support.

Context-switch time is overhead; the system does no useful work while switching.

Steps in Context Switching

Save context of processor including program counter and other registers.
Update the PCB of the running process with its new state and other associate information.
Move PCB to appropriate queue - ready, blocked,
Select another process for execution.
Update PCB of the selected process.
Restore CPU context from that of the selected process.

THE CONCEPTS OF PROCESS

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An operating system executes a variety of programs:

Batch System – jobs
Time-Shared Systems – user programs or tasks
Textbook uses the terms job and process almost interchangeably.

PROCESS – a program in execution; process execution must progress in sequential fashion.

A process includes:

Program Counter

Stack

Data Section

A. PROCESS STATE

A process can be in one of many possible states:

New: The process is being created.

Running: Instructions are being executed.

Waiting: The process is waiting for some event to occur.

Ready: The process is waiting to be assigned to a process.

Terminated: The process has finished execution.

PROCESS TRANSITIONS

As a process executes, it changes its state

Fig. Process State Transition Diagram

B. PROCESS CONTROL BLOCK

Each process in the operating system is represented by a process control block (PCB) – also called a task control block.

Information associated with each process includes:
- Process state – new, ready, running, waiting...
- Process identification information
° Unique process identifier (PID) - indexes (directly or indirectly) into the process table.
° User identifier (UID) - the user who is responsible for the job.
° Identifier of the process that created this process (PPID).
- Program counter – To indicate the next instruction to be executed for this process.
- CPU registers – include index registers, general purpose registers etc. so that the process can be restarted correctly after an interrupt occurs.
- CPU scheduling information – Such as process priority, pointers to scheduling queues etc.
- Memory-management information – Include base and limit register, page tables etc.
- Accounting information – Amount of CPU and real time used, time limits, account number, job or process numbers and so on.
- I/O status information – List of I/O devices allocated to this process, a list of open files etc.

C. THREADS

A thread, also called a lightweight process (LWP), is the basic unit of CPU utilization.

It has its own program counter, a register set, and stack space.

It shares with the pear threads its code section, data section, and OS resources such as open files and signals, collectively called a task.

The idea of a thread is that a process has five fundamental parts: code ("text"), data, stack, file I/O, and signal tables. "Heavy-weight processes" (HWPs) have a significant amount of overhead when switching: all the tables have to be flushed from the processor for each task switch. Also, the only way to achieve shared information between HWPs is through pipes and "shared memory". If a HWP spawns a child HWP using fork(), the only part that is shared is the text.
Threads reduce overhead by sharing fundamental parts. By sharing these parts, switching happens much more frequently and efficiently. Also, sharing information is not so "difficult" anymore: everything can be shared.

User-Level and Kernel-Level Threads

There are tow types of thread: user-level and kernel-level.
User-level avoids the kernel and manages the tables itself.
These threads are implemented in user-level libraries rather than via system calls.
Often this is called "cooperative multitasking" where the task defines a set of routines that get "switched to" by manipulating the stack pointer.
Typically each thread "gives-up" the CPU by calling an explicit switch, sending a signal or doing an operation that involves the switcher. Also, a timer signal can force switches.
User threads typically can switch faster than kernel threads.

Thread States

Threads can be in one of the several states: ready, blocked, running, or terminated.
Like process, threads share the CPU and only one thread at a time is in running state.

QUESTIONS AND ANSWERS

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1. What are the major activities of an Operating System with regards to Process Management?

The operating system is responsible for the following activities in connection with process management.

Process creation and deletion.

Process suspension (process is in I/O wait queue, or “swapped” out to disk, …) and resumption (move to ready queue or execution) – manage the state of the process.
Provision of mechanisms for:

Process synchronization - concurrent processing is supported thus the need for synchronization of processes or threads.
Process communication
Deadlock handling

2. What are the major activities of an Operating System with regards to Memory Management?

Keep track of which parts of memory are currently being used and by whom.
Decide which processes to load when memory space becomes available - long term or medium term scheduler.
Mapping addresses in a process to absolute memory addresses - at load time or run time.
Allocate and deallocate memory space as needed.
Memory partitioning, allocation, paging (VM), address translation, defrag, …
Memory protection

3. What are the major activities of an Operating System with regards to Secondary-Storage Management?

Free space management

Storage allocation

Disk scheduling – minimize seeks (arm movement … very slow operation)

Disk as the media for mapping virtual memory space

Disk caching for performance

Disk utilities: defrag, recovery of lost clusters, etc.

4. What are the major activities of an Operating System with regards to File Management?

File creation and deletion - system calls or commands.
Directory creation and deletion - system calls or commands.
Support of primitives for manipulating files and directories in an efficient manner - system calls or commands.
Mapping files onto secondary storage.
File backup on stable (nonvolatile) storage media.
EX: File Allocation Table (FAT) for Windows/PC systems

5. What is the purpose of the command-interpreter?

The program that reads and interprets control statements is called variously:
·command-line interpreter (Control card interpreter in the “old batch days”)
·shell (in UNIX)
Command.com for external commands in DOS
Its function is to get and execute the next command statement.

SYSTEM BOOT

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- Operating system must be made available to hardware so hardware can start it

Small piece of code – bootstrap loader, locates the kernel, loads it into memory, and starts it
Sometimes two-step process where boot block at fixed location loads bootstrap loader
When power initialized on system, execution starts at a fixed memory location

- Firmware used to hold initial boot code

OPERATING SYSTEM GENERATION

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- Operating systems are designed to run on any of a class of machines; the system must be configured for each specific computer site

- SYSGEN program obtains information concerning the specific configuration of the hardware system

- Booting – starting a computer by loading the kernel

- Bootstrap program – code stored in ROM that is able to locate the kernel, load it into memory, and start its execution

VIRTUAL MACHINE

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- A virtual machine takes the layered approach to its logical conclusion. It treats hardware and the operating system kernel as though they were all hardware

- A virtual machine provides an interface identical to the underlying bare hardware

- The operating system host creates the illusion that a process has its own processor and (virtual memory)

- Each guest provided with a (virtual) copy of underlying computer

VIRTUAL MACHINE HISTORY AND BENEFITS

- First appeared commercially in IBM mainframes in 1972
- Fundamentally, multiple execution environments (different operating systems) can share the same hardware
- Protect from each other
- Some sharing of file can be permitted, controlled
- Commutate with each other, other physical systems via networking
- Useful for development, testing
- Consolidation of many low-resource use systems onto fewer busier systems
- “Open Virtual Machine Format”, standard format of virtual machines, allows a VM to run within many different virtual machine (host) platforms

EXAMPLES

JAVA VIRTUAL MACHINE

- Compiled Java programs are platform-neutral bytecodes executed by a Java Virtual Machine (JVM)
- JVM consists of

Class loader
Class verifier
Runtime interpreter

- Just-In-Time (JIT) compilers increase performance

SYSTEM STRUCTURE

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Simple Structure

-->View the OS as a series of levels
-->Each level performs a related subset of functions
-->Each level relies on the next lower level to perform more primitive functions
-->This decomposes a problem into a number of more manageable subproblems

Layered Approach

The operating system is divided into a number of layers (levels), each built on top of lower layers. The bottom layer (layer 0), is the hardware; the highest (layer N) is the user interface.

With modularity, layers are selected such that each uses functions (operations) and services of only lower-level layers.

<--MS-DOS Layered Structure-->

SYSTEM CALLS

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System calls provide the interface between a process and the operating system. These calls are generally available as assembly language instructions

Some systems also allow to make system calls from a high level language, such as C.

Three general methods are used to pass parameters between a running program and the operating system.
- Pass parameters in registers.
- Store the parameters in a table in memory, and the table address is passed as a parameter in a register.
- Push (store) the parameters onto the stack by the program, and pop off the stack by operating system.

<--Types of System Calls-->

-->Process control – load, execute, abort, end, create process, allocate and free memory, wait event etc.

-->File management – Create file, delete file, open, close, read, write, get file attribute etc.

-->Device management – Request device, release device, read, write, logically attach or detach device etc.

-->Information maintenance – Get time and date, set time and date, get process attribute etc.
-->Communications – create, close communication connection, send, receive messages, etc.

OPERATING SYSTEM SERVICES

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Program execution – system capability to load a program into memory and to run it.

I/O operations – since user programs cannot execute I/O operations directly, the operating system must provide some means to perform I/O.

File-system manipulation – program capability to read, write, create, and delete files.

Communications – exchange of information between processes executing either on the same computer or on different systems tied together by a network. Implemented via shared memory or message passing.

Error detection – ensure correct computing by detecting errors in the CPU and memory hardware, in I/O devices, or in user programs.

Additional functions exist not for helping the user, but rather for ensuring efficient system operations.
•Resource allocation – allocating resources to multiple users or multiple jobs running at the same time.
•Preemptable, nonpreemptable resources
•Deadlock prevention and detection models
•Accounting – keep track of and record which users use how much and what kinds of computer resources for account billing or for accumulating usage statistics.
•Protection – ensuring that all access to system resources is controlled.

SYSTEM COMPONENTS

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SYSTEM COMPONENT

Operating Systems Process Management

A process is a program in execution. A process needs certain resources: CPU time, memory (address space), files, and I/O devices, to accomplish its task.

The operating system is responsible for the following activities in connection with process management.
-->Process creation and deletion.
-->Process suspension and resumption.
-->Provision of mechanisms for:
-->Process synchronization
-->Process communication

Main Memory Management

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

The operating system is responsible for the following activities in connections with memory management:

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

File Management

A file is a collection of related information defined by its creator. Commonly, files represent programs (both source and object forms) and data.

The operating system is responsible for the following activities in connections with file management:

-->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.

Before mounting,
-->Files on floppy are inaccessible

After mounting floppy on b,
-->Ffiles on floppy are part of file hierarchy

I/O System Management

The I/O system consists of:
-->A buffer-caching system
-->A general device-driver interface
-->Drivers for specific hardware devices

Secondary Storage Management

Since main memory (primary storage) is volatile and too small to accommodate all data and programs permanently, the computer system must provide secondary storage to back up main memory.

Most modern computer systems use disks as the principle on-line storage medium, for both programs and data.

The operating system is responsible for the following activities in connection with disk management:

-->Free space management
-->Storage allocation
-->Disk scheduling

Protection System

Protection refers to a mechanism for controlling access by programs, processes, or users to both system and user resources.

The protection mechanism must:

-->Distinguish between authorized and unauthorized usage.
-->Specify the controls to be imposed.
-->Provide a means of enforcement.

Command-Interpreter System

Command-Interpreter reads commands from the user or from a ﬁle of commandsand executes them, usually by turning them into one or more systemcalls. It is usually not part of the kernel since the command interpreteris subject to changes.

The program that reads and interprets control statements is called variously:
-->command-line interpreter
-->shell (in UNIX)

Its function is to get and execute the next command statement

RAM AND DRAM

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Computer programs must be in main memory (also called random-access memory or RAM) to be executed. Main memory is the only large storage area(millions to billions of bytes) that the processor can access directly. It is implemented in a semiconductor technology called dynamic random-access memory (DRAM), which forms an array of memory words. Each word has its own address. Interaction is achieved through a sequence of load or store instructions to specific memory addresses. The load instruction moves the content of a register to main memory. Aside from explicit loads and stores, the CPU automatically loads instructions from main memory for execution.

DIRECT MEMORY ACCESS

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Direct Memory Access (DMA) Structure

• Used for high-speed I/O devices able to transmit information at close to memory speeds.

• Device controller transfers blocks of data from buffer storage directly to main memory without CPU intervention.

• Only one interrupt is generated per block, rather than the one interrupt per byte.

HARDWARE PROTECTION

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• When executing in kernel mode, the operating system has unrestricted access to both kernel and user’s memory.

• The load instructions for the base and limit registers are privileged instructions.

<--DUAL MODE OPERATION -->

• Sharing system resources requires operating system to ensure that an incorrect program cannot cause other programs to execute incorrectly.

• Provides hardware support to differentiate between at least two modes of operations.

1. User mode – execution done on behalf of a user.

2. Kernel mode (also monitor mode, supervisor mode or system mode) – execution done on behalf of operating system.

• Mode bit added to computer hardware to indicate the current mode: kernel (0) or user (1).• When an interrupt or fault occurs hardware switches to kernel mode.

• Privileged instructions can be issued only in kernel mode.

<--I/O PROTECTION-->

• All I/O instructions are privileged instructions.

• Given the I/O instructions are privileged, how does the user program perform I/O?

• System call

– the method used by a process to request action by the operating system.

– Usually takes the form of a trap to a specific location in the interrupt vector.

– Control passes through the interrupt vector to a service routine in the OS, and the mode bit is set to kernel mode.

– The kernel verifies that the parameters are correct and legal, executes the request, and returns control to the instruction following the system call.

<--Use of a System Call to Perform an I/O-->

• Must ensure that a user program could never gain control of the computer in kernel mode. Otherwise, undesirable actions can be done e.g. a user program that, as part of its execution, stores a new address in the interrupt vector.

<--MEMORY PROTECTION-->

• Must provide memory protection at least for the interrupt vectorand the interrupt service routines.

• In order to have memory protection, add two registers that determine the range of legal addresses a program may access:

– Base Register – holds the smallest legal physical memory address.

– Limit Register – contains the size of the range

• Memory outside the defined range is protected.

<--CPU PROTECTION-->

• Timer

– interrupts computer after specified period to ensure operating system maintains control.

– Timer is decremented every clock tick.

– When timer reaches the value 0, an interrupt occurs.

• Timer commonly used to implement time sharing.

• Time also used to compute the current time.

• Load-timer is a privileged instruction.

STORAGE HIERARCHY

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• Storage systems organized in hierarchy.
– Speed
– Cost
– Size
– Volatility

<--STORAGE HEIRARCHY(MEMORY HEIRARCHY)-->

Click here to see full image size

• Caching – copying information into faster storage system; main memory can be viewed as a cache for secondary storage.

–improve performance where a large access-time or transfer-rate disparity exists between two components) Memory caching: add cache (faster and smaller memory) between CPU and main memory

--> When need some data, check if it’s in cache

-->If yes, use the data from cache

--> If not, use data from main memory and put a copy in cache

– Disk caching: main memory can be viewed as a cache for disks

<--Cache Coherency and Consistency-->

• Cache coherency in multiprocessor systems
- Each CPU has a local cache
- A copy of X may exist in several caches --> must make sure that an update of X in one cache is immediately reflected in all other caches where X resides
- Hardware problem
• Cache consistency in distributed systems
- A master copy of the file resides at the server machine
- Copies of the same file scattered in caches of different client machines
- Must keep the cached copies consistent with the master file
- OS problem

STORAGE STRUCTURE

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• Main Memory – only large storage media that the CPU can access directly.
• Secondary Storage – extension of main memory that provides large nonvolatile storage capacity.
• Magnetic Disks
– rigid metal or glass platters covered with magnetic recording material.
– Disk surface is logically divided into tracks, which are subdivided into sectors.
– The disk controller determines the logical interaction between the device and the computer.

-->>Moving Head Mechanism

• Magnetic Tapes

Magnetic tape is a medium for magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of plastic. Nearly all recording tape is of this type, whether used for recording audio or video or for computer data storage. It was originally developed in Germany, based on the concept of magnetic wire recording. Devices that record and playback audio and video using magnetic tape are generally called tape recorders and video tape recorders respectively. A device that stores computer data on magnetic tape can be called a tape drive, a tape unit, or a streamer.
Magnetic tape revolutionized the broadcast and recording industries. In an age when all radio (and later television) was live, it allowed programming to be prerecorded. In a time when gramophone records were recorded in one take, it allowed recordings to be created in multiple stages and easily mixed and edited with a minimal loss in quality between generations. It is also one of the key enabling technologies in the development of modern computers. Magnetic tape allowed massive amounts of data to be stored in computers for long periods of time and rapidly accessed when needed.
Today, many other technologies exist that can perform the functions of magnetic tape. In many cases these technologies are replacing tape. Despite this, innovation in the technology continues and tape is still widely used.

DEVICE-STATUS TABLE

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Device-status table contains entry for each I/O deviceindicating its type, address, and state.

<--DEVICE STATUS TABLE-->

Click here to see full size of image

MONITOR MODE AND USER MODE

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• Sharing system resources requires operating system to ensure that an incorrect program cannot cause other programs to execute incorrectly

• Provides hardware support to differentiate between at least two modes of operations.

1. User mode – execution done on behalf of a user.

2. Kernel mode (also monitor mode, supervisor mode or system mode) – execution done on behalf of operating system.

INTERRUPT AND TRAP

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Interrupts and Traps. A great deal of the kernel consists of code that is invoked as the result of a interrupt or a trap.
While the words "interrupt" and "trap" are often used interchangeably in the context of operating systems, there is a distinct difference between the two.
An interrupt is a CPU event that is triggered by some external device.
A trap is a CPU event that is triggered by a program. Traps are sometimes called software interrupts. They can be deliberately triggered by a special instruction, or they may be triggered by an illegal instruction or an attempt to access a restricted resource.
When an interrupt is triggered by an external device the hardware will save the the status of the currently executing process, switch to kernel mode, and enter a routine in the kernel.
This routine is a first level interrupt handler. It can either service the interrupt itself or wake up a process that has been waiting for the interrupt to occur.
When the handler finishes it usually causes the CPU to resume the processes that was interrupted. However, the operating system may schedule another process instead.
When an executing process requests a service from the kernel using a trap the process status information saved, the CPU is placed in kernel mode, and control passes to code in the kernel.
This kernel code is called the system service dispatcher. It examines parameters set before the trap was triggered, often information in specific CPU registers, to determine what action is required. Control then passes to the code that performs the desired action.
When the service is finished, control is returned to either the process that triggered the trap or some other process.
Traps can also be triggered by a fault. In this case the usual action is to terminate the offending process. It is possible on some systems for applications to register handlers that will be evoked when certain conditions occur -- such as a division by zero.

BOOTSTRAP PROGRAM

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1.) BOOTSTRAP PROGRAM

--> Code stored in ROM that is able to locate the kernel, load it into memory, and start its execution

--> In computing, booting is a bootstrapping process that starts operating systems when the user turns on a computer system.
Most computer systems can only execute code found in the memory (ROM or RAM); modern operating systems are mostly stored on hard disk drives, LiveCDs and USB flash drive. Just after a computer has been turned on, it doesn't have an operating system in memory. The computer's hardware alone cannot perform complicated actions of the operating system, such as loading a program from disk on its own; so a seemingly irresolvable paradox is created: to load the operating system into memory, one appears to need to have an operating system already installed.

DIFFERENCE BETWEEN BATCH SYSTEM, MULTIPROGRAMMED SYSTEM, AND TIME_SHARING SYSTEM

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BATCH SYSTEM

In computing, system for processing data with little or no operator intervention. Batches of data are prepared in advance to be processed during regular ‘runs’ (for example, each night). This allows efficient use of the computer and is well suited to applications of a repetitive nature, such bulk file format conversion, as a company payroll, or the production of utility bills.

MULTIPROGRAMMED SYSTEM

It's an OS which keeps several jobs(programs) in memory at a time .The operating system picks and begins to execute one of the jobs in the memory. Eventually the job may have to wait for some task like a tape to be mounted,... Or an input output operation to be complete.In a multiprogrammed OS the OS is not idle it's simply switch to another job and executes it .As there is always some jobs to execute , the CPU will never be idle.

TIME-SHARING SYSTEM

Time-sharing is sharing a computing resource among many users by multitasking. Its introduction in the 1960s, and emergence as the prominent model of computing in the 1970s, represents a major historical shift in the history of computing. By allowing a large number of users to interact simultaneously on a single computer, time-sharing dramatically lowered the cost of providing computing, while at the same time making the computing experience much more interactive.

ESSENTIAL PROPERTIES OF THE FOLLOWING TYPES OF O.S.

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· BATCH

-> Jobs with similar needs are batched together and run through the computer as a group, by an operator or automatic job sequencer. Performance is increased by attempting to keep CPU and I/O devices busy at all times through buffering, off-line operation, spooling, and multiprogramming.

· TIME-SHARING

-> The first involved timesharing or timeslicing. The idea of multiprogramming was extended to allow for multiple terminals to be connected to the computer, with each in-use terminal being associated with one or more jobs on the computer. The operating system is responsible for switching between the jobs, now often called processes, in such a way that favored user interaction. If the context-switches occurred quickly enough, the user had the impression that he or she had direct access to the computer.

· REAL TIME

-> A real-time system is used when rigid time requirements have been placed on the operation of a processor or the flow of data thus it is often used as a control device in a dedicated application. Sensors bring data to the computer. A real-time system has well-defined, fixed time constraints. Processing must be done within the defined constraints, or the system will fail.

· NETWORK

-> Networked systems consist of multiple computers that are networked together, usually with a common operating system and shared resources. Users, however, are aware of the different computers that make up the system.

· DISTRIBUTED

-> A network, in the simplest terms, is a communication path between two or more systems. Distributed systems depend on networking for their functionality.
1. Client-Server Systems
2. Peer-to-Peer Systems

also consist of multiple computers but differ from networked systems in that the multiple computers are transparent to the user. Often there are redundant resources and a sharing of the workload among the different computers, but this is all transparent to the user.

· HANDHELD

-> Handheld systems include personal digital assistants (PDAs) or cellular telephones with connectivity to a network such as the Internet.

DIFFERENCE BETWEEN A STAND ALONE PC AND WORKSTATION CONNECTED TO A NETWORK

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Differentiate the design issues of OS between a stand-alone PC and a Workstation connected to a network.

->A stand-alone PC works on its own. While in a workstation connected to a network, you can freely share your files and databases to other PC.A desktop or laptop computer that is used on its own without requiring a connection to a local area network (LAN) or wide area network (WAN). Although it may be connected to a network, it is still a stand-alone PC as long as the network connection is not mandatory for its general use.In offices throughout the 1990s, millions of stand-alone PCs were hooked up to the local network for file sharing and mainframe access. Today, computers are commonly networked in the home so that family members can share an Internet connection as well as printers, scanners and other peripherals. When the computer is running local applications without Internet access, the machine is technically a stand-alone PC. A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multiuser operating system. The term workstation has also been used to refer to a mainframe computer terminal or a PC connected to a network.

OPERATING SYSTEM VIEWPOINTS

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Operating Systems can be explored from two viewpoints: the user and the system.

USER VIEW
The user view of the computer varies by the interface being used. Most computer users sit in front of a PC, consisting of a monitor, keyboard, mouse and system unit. Such a system is designed for one user to monopolize its resources, to maximize the work that the user is performing. In this case,the operating system is designed mostly for ease of use, with some attention paid to performance, and none paid to resource utilization.

Some users sit at a terminal connected to a mainframe or minicomputer. Other users are accessing the same computer through other terminals. These users share resources and may exchange information. The operating system is designed to maximize resource utilization.

Other users sit at workstations, connected to networks of other workstations and servers. These users have dedicated resources at their disposal, but they also share resources such as networking and servers.

Recently, many varieties of handheld computers have come into fashion. These devices are mostly standalone, used singly by individual users. Some are connected to networks, either directly by wire or through wireless modems. Due to power and interface limitations they perform relatively few remote operations. These operating systems are designed mostly for individual usability, but performance per amount of battery life is important as well.

Some computers have little or no user view. For example, embedded computers in home devices and automobiles may have numeric keypad, and may turn indicator lights on or off to show status, but mostly they and their operating systems are designed to run without user intervention.

SYSTEM VIEW

We can view an operating system as a resource allocator. A computer system has many resources - hardware and software - that may be required to solve a problem. The operating system acts as the manager of these resources.

An operating system can also be viewed as a control program that manages the execution of user programs to prevent errors and improper use of the computer. It is especially concerned with the operation and control of I/O devices.

We have no universally accepted definition of what is part of the operating system. A simple viewpoint is that it includes everything a vendor ships when you order “the operating system”.

A more common definition is that the operating system is the one program running at all times on the computer (usually called the kernel), with all else being application programs. This is the one that we generally follow.

CLIENT-SERVER SYSTEM AND PEER-TO-PEER SYSTEM

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CLIENT-SERVER

-> System or networking is a distributed application architecture that partitions tasks or work loads between service providers (servers) and service requesters, called clients.[1] Often clients and servers operate over a computer network on separate hardware. A server is a high-performance host that is a registering unit and shares its resources with clients. A client does not share any of its resources, but requests a server's content or service function. Clients therefore initiate communication sessions with servers which await (listen to) incoming requests.

-> Client-server describes the relationship between two computer programs in which one program, the client program, makes a service request to another, the server program. Standard networked functions such as email exchange, web access and database access, are based on the client-server model. For example, a web browser is a client program at the user computer that may access information at any web server in the world. To check your bank account from your computer, a web browser client program in your computer forwards your request to a web server program at the bank. That program may in turn forward the request to its own database client program that sends a request to a database server at another bank computer to retrieve your account balance. The balance is returned to the bank database client, which in turn serves it back to the web browser client in your personal computer, which displays the information for you.

A server based network (i.e: not peer-to-peer):

PEER-TO-PEER SYSTEM

-> Peer-to-peer (P2P) system or networking is a method of delivering computer network services in which the participants share a portion of their own resources, such as processing power, disk storage, network bandwidth, printing facilities. Such resources are provided directly to other participants without intermediary network hosts or servers.[1] Peer-to-peer network participants are providers and consumers of network services simultaneously, which contrasts with other service models, such as traditional client-server computing.

A peer-to-peer based network:

SYMMETRIC MULTIPROCESSING AND ASSYMETRIC MULTI PROCESSING

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SYMMETRIC MULTIPROCESSING

- In computing, symmetric multiprocessing or SMP involves a multiprocessor computer-architecture where two or more identical processors can connect to a single shared main memory. Most common multiprocessor systems today use an SMP architecture. In the case of multi-core processors, the SMP architecture applies to the cores, treating them as separate processors.
SMP systems allow any processor to work on any task no matter where the data for that task are located in memory; with proper operating system support, SMP systems can easily move tasks between processors to balance the workload efficiently.

ASSYMETRIC MULTIPROCESSING

- Asymmetric multiprocessing or ASMP is a type of multiprocessing supported in DEC's VMS V.3 as well as a number of older systems including TOPS-10 and OS-360. It varies greatly from the standard processing model that we see in personal computers today. Due to the complexity and unique nature of this architecture, it was not adopted by many vendors or programmers during its brief stint between 1970 - 1980.
Where as a symmetric multiprocessor or SMP treats all of the processing elements in the system identically, an ASMP system assigns certain tasks only to certain processors. In particular, only one processor may be responsible for fielding all of the interrupts in the system or perhaps even performing all of the I/O in the system. This makes the design of the I/O system much simpler, although it tends to limit the ultimate performance of the system. Graphics cards, physics cards and cryptographic accelerators which are subordinate to a CPU in modern computers can be considered a form of asymmetric multiprocessing.[citation needed] SMP is extremely common in the modern computing world, when people refer to "multi core" or "multi processing" they are most commonly referring to SMP.

GOALS OF OPERATING SYSTEM

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OPERATING SYSTEM

- (commonly abbreviated to either OS or O/S) is an interface between hardware and user; it is responsible for the management and coordination of activities and the sharing of the resources of the computer. The operating system acts as a host for computing applications that are run on the machine. As a host, one of the purposes of an operating system is to handle the details of the operation of the hardware. This relieves application programs from having to manage these details and makes it easier to write applications. Almost all computers (including handheld computers, desktop computers, supercomputers, video game consoles) as well as some robots, domestic appliances (dishwashers, washing machines), and portable media players use an operating system of some type. [1] Some of the oldest models may however use an embedded operating system, that may be contained on a compact disk or other data storage device.

GOALS OF THE OPERATING SYSTEM:

It is easier to define an operating system by what it does than what it is, but even this can be tricky. The primary goal of some operating system is convenience for the user. The primary goal of other operating system is efficient operation of the computer system. Operating systems and computer architecture have influenced each other a great deal. To facilitate the use of the hardware, researchers developed operating systems. Users of the operating systems then proposed changes in hardware design to simplify them. In this short historical review, notice how identification of operating-system problems led to the introduction of new hardware features.

PARALLEL SYSTEM (types and advantages)

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PARALLEL SYSTEMS

- Multiprocessor systems with more than one CPU in close communication.

- Tightly coupled system – processors share memory and aclock; communication usually takes place through the shared memory.

- Symmetric multiprocessing (SMP)

·Each processor runs and identical copy of the operating system.

·Many processes can run at once without performance deterioration.

·Most modern operating systems support SMP

- Asymmetric multiprocessing

·Each processor is assigned a specific task; master processor schedules and allocated work to slave processors.

· More common in extremely large systems

Advantages of parallel system:

1. Increased throughput

2. Economical

3. Increased reliability

3.1. graceful

3.2. degradationfail-soft systems

Lab Exercises-Quiz No.1(third trinal)

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Questions to be answered.

1. What is the reason for technicians to wear special wrist grounding straps?

The safety wrist strap with grounding cord (integrated 1 MOhmresistor) for the derivation of electrostatic charges, which canadhere to persons at ESD work stations. The strap guaranteesconstant earthing and therefore avoids electrostatic charging atpersons. An ungrounded person causes capacity changes whenmoving, which could lead to spikes at worst case. Those spikesagain are able to damage or destroy electronic componentsNormally dangerous body voltages which may destroy electro-nic components are derivated when a person touches conducti-ve table covering. Charging caused by insulating floors, cloth andchair seats also have to be discharged. Furthermore there is nopermanent contact to the floor when the person is sittingTherefore an additional earthing via wrist strap is necessary.

http://www.canespa.de/catalog/File/hk/en/Seite26-28.pdf

2. After installing a new computer component why is it important to obtain the most current driver for it?

A device driver is a program that controls a particular type of device that is attached to your computer. There are device drivers for printers, displays, CD-ROM readers, diskette drives, and so on. When you buy an operating system, many device drivers are built into the product. However, if you later buy a new type of device that the operating system didn't anticipate, you'll have to install the new device driver. A device driver essentially converts the more general input/output instructions of the operating system to messages that the device type can understand. You need to have a newer version of your device driver because a newer version of a device driver has new features on it.

http://searchenterprisedesktop.techtarget.com/sDefinition/0,,sid192_gci211938,00.html

3. What are the steps required to install a peripheral device?

Adding a Peripheral Device to a System
Adding a new peripheral device that is not-pluggable usually involves the following:
1.Shutting down the system
2.Connecting the device to the system
3.Rebooting the system
Use How to Add a Peripheral Device to add the following devices that are not hot-pluggable to a system:
CD-ROM
Secondary disk drive
Tape drive
SBUS card
In some cases, you might have to add a third-party device driver to support the new device.
For information on hot-plugging devices, see Chapter 6, Dynamically Configuring Devices (Tasks).
How to Add a Peripheral Device

Become superuser.
(Optional) If you need to add a device driver to support the device, complete the procedure How to Add a Device Driver.
Create the /reconfigure file.
# touch /reconfigure
The /reconfigure file causes the Solaris software to check for the presence of any newly installed devices the next time you turn on or boot your system.
Shut down the system.
# shutdown -i0 -g30 -y

-i0
Brings the system to the 0 init state, which is the appropriate state for turning the system power off for adding and removing devices.
-g30
Shuts the system down in 30 seconds. The default is 60 seconds.
-y
Continues the system shutdown without user intervention. Otherwise, you are prompted to continue the shutdown process.
Select one of the following to turn off power to the system after it is shut down:
For SPARC platforms, it is safe to turn off power if the ok prompt is displayed.
For x86 platforms, it is safe to turn off power if the type any key to continue prompt is displayed.
Turn off power to all peripheral devices.
For the location of power switches on any peripheral devices, refer to the hardware installation guides that accompany your peripheral devices.
Install the peripheral device, making sure that the device you are adding has a different target number than the other devices on the system.
Often, a small switch is located at the back of the disk for selecting the target number.
Refer to the hardware installation guide that accompanies the peripheral device for information on installing and connecting the device.
Turn on the power to the system.
The system boots to multiuser mode, and the login prompt is displayed.
Verify that the peripheral device has been added by attempting to access the device.
For information on accessing the device, see Accessing Devices.

http://www.answers.com/topic/how-to-install-a-pc-peripheral

4. If a newly installed peripheral device does not function properly what steps can be taken to correct the problem?

Check if the product or the hardware you bought has no defect or company defects.

You should also check for driver updates for all your peripheral devices. If you're up to date, and you started having issues around the time you last updated a driver, try backing down to a lower version.

http://www.bautforum.com/archive/index.php/t-62740.html

5. Explain the technique used to help protect data on a hard drive when doing a clean install?

One of the techniques available to help protect data is to divide the hard drive into multiple partitions. With a clean install, many technicians prefer to create one partition for data and a separate partition for the OS. This enables an OS to be upgraded without the risk of losing data. It also simplifies backup and recovery of data files.

http://lryuzakitutorials.blogspot.com/

6. Explain what a software patch is.

A patch is a piece of program code that can correct a problem or enhance thefunctionality of an application program or OS. They are usually provided by themanufacturer to repair a known vulnerability or reported problem.

As people begin to use a software program with frequency, they may note glitches or problems that were not observed during beta testing of the program. Alternately, older software can have compatibility issues with newer systems, or newer software may be incompatible with older systems. In these cases, and often to increase sales or use of software, programmers may create what is called a software patch, designed to fix small bugs, glitches, or address software-to-hardware or operating system compatibility issues.
If you notice consistent problems with a program, it’s easy to research on the Internet whether there is a software patch that might fix the program. In most cases these patches are free, and the majority of them are now simply downloaded from the Internet. A fair percentage of these patches help to address problems, but a poorly composed software patch may actually create new problems.
A software patch has several alternate names. When significant aspects of the software are altered, these may be called software updates instead. Some may be sold instead of available via free download. This is common with various computer games, where you can purchase what are called extension packs. These may change the rules of a game, add new features, or add new scenarios so people continue to play the game. When a game has been on the market for a while, it may be sold in a bundle with several extension packs.
Sometimes, programmers create small free features for current games that don’t warrant being called extension packs. For example in games like Zoo Tycoon® you can download tiny bits of programming that will add a few extra elements to a game, like extra animals you can raise or donation centers to collect more money from your guests. Also, when a game or other software type is popular but has existed for a few years, it may exhibit compatibility problems with newer software, newer computers or newer operating systems. Fans of a type of software that has not been updated to work with newer systems or computers often request that a software patch be made so they can extend the life of the programs they enjoy.
You’ll often find that you need a software patch for programs that were designed primarily for one type of hardware. For instance popular PC programs may not run or work as well on Mac®: computers. Sometimes a programmer needs to create both Mac and PC versions. Other times, a program designed for one system isn’t as effective on another and merely requires a software patch to fix glitches.
The modern installation of the software patch is much easier than in the past. This is especially true on PC systems where a person might have to go through multiple command sets in order to get the patch to work. Instead after downloading the software patch, you usually only need to install it, a matter of a couple of minutes depending upon the size of the patch and the speed of your computer.

http://www.wisegeek.com/what-is-a-software-patch.htm

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Redhat 8.0 Installation Guide with Screenshots

NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE1) Red Hat Linux Boot screen: (Image 1.1)

2) Welcome to Red Hat: (Image 1.2)

3) Language Selection: (Image 1.3)

4) Keyboard Configuration: (Image 1.4)

5) Mouse Configuration: (Image 1.5)

6) Installation type: (Image 1.6)

7) Partitioning your system: (Image 1.7)

8) Warning dialog box: (Image 1.8)

9) Automatic Partitioning: (Image 1.9)

10) New hard drive structure: (Image 1.10)

11) Boot loader options: (Image 2.1)

12) Install a boot loader: (Image 2.2)

13) Network setup: (Image 2.3)

14) Firewall setup: (Image 2.4)

15) Language Selection: (Image 2.5)

16) Time Zone Selection: (Image 2.6)

17) Create a root or administrator password: (Image 2.7)

18) Add users: (Image 2.8)

19) Add as many users as you wish: (Image 2.9)

20) Default package configuration: (Image 2.10)

21) Selecting exactly what packages: (Image 2.11)

22) Installation will now start: (Image 3.1)

23) Formatting of the hard drive: (Image 3.2)

24) Transfer of the install image: (Image 3.3)

25) Installation of all selected packages: (Image 3.4)

26) Insert the next CD soon: (Image 3.5)

27) Boot floppy creation: (Image 3.6)

28) Graphics card setup: (Image 3.7)

29) Monitor Setup: (Image 3.8)

30) Desktop resolution: (Image 3.9)

31) Install complete: (Image 3.10)

32) Grub boot loader: (Image 4.1)

33) Boot Red Hat: (Image 4.2)

34) Logon: (Image 4.3)

35) Gnome Desktop: (Image 4.4)

36) BlackViper.com in Mozilla: (Image 4.5)

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NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE

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NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE

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NOTE: IF IMAGE IS BLURRED, DOUBLE CLICK TO VIEW IMAGE

1) Red Hat Linux Boot screen: (Image 1.1)