The difference between 64 and 32 bit processors

Monday, December 7, 2009

In the future, the battle between 64 bit vs 32 bit processors will inevitably yield the 64 bit processor as the victor, but this transition is going to take some time.

First, I’ll talk about the pure mathematics and structure of the processors that are involved here. I’ll keep this part short and sweet.


A bit is short for “binary digit.” It is basically how a computer stores and makes references to data, memory, etc. A bit can have a value of 1 or 0, that’s it. So binary code is streams of 1’s and 0’s, such as this random sequence 100100100111. These bits are also how your processor does calculations. By using 32 bits your processor can represent numbers from 0 to 4,294,967,295 while a 64-bit machine can represent numbers from 0 to 18,446,744,073,709,551,615. Obviously this means your computer can do math with larger numbers, and be more efficient with smaller numbers.

Now see, that description wasn’t too bad, but the question is how does this affect you, the average PC owner? The largest benefit will go to academic institutions and private companies, where large calculations are being performed, huge databases are being accessed, and complex problems are being solved.

Everyone that doesn’t fall into that category will see some benefit of using 64 bit processors over 32 bit processors, but not much in today’s marketplace. The AMD Athlon 64-bit processor is completely backward compatible, meaning you can currently use it with 32-bit operating systems and software programs. You will see some benefits by using this setup, but because the programs weren’t written to take advantage of the extra power, they won’t use much of it.

The true benefits of this set up don’t come from the amount of bits, but by the improved structure of the 64 bit vs 32 bit processor's older structure. A 64-bit processor is made with more advanced silicon processes, have more transistors, and faster speeds. This is currently where the true benefit of switching to a 64-bit processor lays.

As for 64-bit operating systems and software, many are in the works, but nothing is in final version. Microsoft has released a beta version of Windows XP that takes advantage of the 64 bit technology, but there are still issues. The problem is when you run 32-bit software programs in the environment of a 64-bit operating system. Many programs won’t work properly, such as Adobe Acrobat and Windows Media Player, for example. Another issue is RAM. You really need about 4 GB of RAM to take full advantage of the capabilities offered by a 64-bit processor, while most PC owners have less than 1 GB under their computer’s hood.

So, the question now is should you buy a 64 bit processor now, or wait?

Disadvantages:

You’re currently not able to take full advantage of the technology because the software vendors haven’t made the switch from 32-bit to 64-bit processors.


Most AMD Athlon 64 bit processors are expensive, with prices sure to go down in the future.

Advantages:

Better performance out of a 32-bit operating system.


Probably the last processor you’ll have to buy for many years to come.

Core Java Interview Questions with Answers

Thursday, October 22, 2009

41. What is the catch or declare rule for method declarations?

If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.

42. What is the difference between a MenuItem and a CheckboxMenuItem?

The CheckboxMenuItem class extends the MenuItem class to support a menu item that may be checked or unchecked.

43. What is a task's priority and how is it used in scheduling?

A task's priority is an integer value that identifies the relative order in which it should be executed with respect to other tasks. The scheduler attempts to schedule higher priority tasks before lower priority tasks.

44. What class is the top of the AWT event hierarchy?

The java.awt.AWTEvent class is the highest-level class in the AWT event-class hierarchy.

45. When a thread is created and started, what is its initial state?

A thread is in the ready state after it has been created and started.

46. Can an anonymous class be declared as implementing an interface and extending a class?

An anonymous class may implement an interface or extend a superclass, but may not be declared to do both.

47. What is the range of the short type?

The range of the short type is -(2^15) to 2^15 - 1.

48. What is the range of the char type?

The range of the char type is 0 to 2^16 - 1.

49. In which package are most of the AWT events that support the event-delegation model defined?

Most of the AWT-related events of the event-delegation model are defined in the java.awt.event package. The AWTEvent class is defined in the java.awt package.

50. What is the immediate superclass of Menu?

MenuItem

51. What is the purpose of finalization?

The purpose of finalization is to give an unreachable object the opportunity to perform any cleanup processing before the object is garbage collected.

52. Which class is the immediate superclass of the MenuComponent class.

Object

53. What invokes a thread's run() method?

After a thread is started, via its start() method or that of the Thread class, the JVM invokes the thread's run() method when the thread is initially executed.

54. What is the difference between the Boolean & operator and the && operator?

If an expression involving the Boolean & operator is evaluated, both operands are evaluated. Then the & operator is applied to the operand. When an expression involving the && operator is evaluated, the first operand is evaluated. If the first operand returns a value of true then the second operand is evaluated. The && operator is then applied to the first and second operands. If the first operand evaluates to false, the evaluation of the second operand is skipped.

55. Name three subclasses of the Component class.

Box.Filler, Button, Canvas, Checkbox, Choice, Container, Label, List, Scrollbar, or TextComponent

56. What is the GregorianCalendar class?

The GregorianCalendar provides support for traditional Western calendars.

57. Which Container method is used to cause a container to be laid out and redisplayed?

validate()

58. What is the purpose of the Runtime class?

The purpose of the Runtime class is to provide access to the Java runtime system.

59. How many times may an object's finalize() method be invoked by the garbage collector?

An object's finalize() method may only be invoked once by the garbage collector.

60. What is the purpose of the finally clause of a try-catch-finally statement?

The finally clause is used to provide the capability to execute code no matter whether or not an exception is thrown or caught.

To be Continued

Core Java Interview Questions with Answers

Wednesday, October 7, 2009

Continutiy

21. Which method of the Component class is used to set the position and size of a component?

setBounds()

22. How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters?

Unicode requires 16 bits and ASCII require 7 bits. Although the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.

23What is the difference between yielding and sleeping?

When a task invokes its yield() method, it returns to the ready state. When a task invokes its sleep() method, it returns to the waiting state.

24. Which java.util classes and interfaces support event handling?

The EventObject class and the EventListener interface support event processing.

25. Is sizeof a keyword?

The sizeof operator is not a keyword.

26. What are wrapped classes?

Wrapped classes are classes that allow primitive types to be accessed as objects.

27. Does garbage collection guarantee that a program will not run out of memory?

Garbage collection does not guarantee that a program will not run out of memory. It is possible for programs to use up memory resources faster than they are garbage collected. It is also possible for programs to create objects that are not subject to garbage collection

28. What restrictions are placed on the location of a package statement within a source code file?

A package statement must appear as the first line in a source code file (excluding blank lines and comments).

29. Can an object's finalize() method be invoked while it is reachable?

An object's finalize() method cannot be invoked by the garbage collector while the object is still reachable. However, an object's finalize() method may be invoked by other objects.

30. What is the immediate superclass of the Applet class?

Panel

31. What is the difference between preemptive scheduling and time slicing?

Under preemptive scheduling, the highest priority task executes until it enters the waiting or dead states or a higher priority task comes into existence. Under time slicing, a task executes for a predefined slice of time and then reenters the pool of ready tasks. The scheduler then determines which task should execute next, based on priority and other factors.

32. Name three Component subclasses that support painting.

The Canvas, Frame, Panel, and Applet classes support painting.

33. What value does readLine() return when it has reached the end of a file?

The readLine() method returns null when it has reached the end of a file.

34. What is the immediate superclass of the Dialog class?

Window

35. What is clipping?

Clipping is the process of confining paint operations to a limited area or shape.

36. What is a native method?

A native method is a method that is implemented in a language other than Java.

37. Can a for statement loop indefinitely?

Yes, a for statement can loop indefinitely. For example, consider the following: for(;;) ;

38. What are order of precedence and associativity, and how are they used?

Order of precedence determines the order in which operators are evaluated in expressions. Associatity determines whether an expression is evaluated left-to-right or right-to-left

39. When a thread blocks on I/O, what state does it enter?

A thread enters the waiting state when it blocks on I/O.

40. To what value is a variable of the String type automatically initialized?

The default value of an String type is null.

Core Java Interview Questions with Answers

1.what is a transient variable?

A transient variable is a variable that may not be serialized.

2.which containers use a border Layout as their default layout?

The window, Frame and Dialog classes use a border layout as their default layout.

3.Why do threads block on I/O?

Threads block on i/o (that is enters the waiting state) so that other threads may execute while the i/o Operation is performed.

4. How are Observer and Observable used?

Objects that subclass the Observable class maintain a list of observers. When an Observable object is updated it invokes the update() method of each of its observers to notify the observers that it has changed state. The Observer interface is implemented by objects that observe Observable objects.

5. What is synchronization and why is it important?

With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object's value. This often leads to significant errors.

6. Can a lock be acquired on a class?

Yes, a lock can be acquired on a class. This lock is acquired on the class's Class object.

7. What's new with the stop(), suspend() and resume() methods in JDK 1.2?

The stop(), suspend() and resume() methods have been deprecated in JDK 1.2.

8. Is null a keyword?

The null value is not a keyword.

9. What is the preferred size of a component?

The preferred size of a component is the minimum component size that will allow the component to display normally.

10. What method is used to specify a container's layout?

The setLayout() method is used to specify a container's layout.

11. Which containers use a FlowLayout as their default layout?

The Panel and Applet classes use the FlowLayout as their default layout.

12. What state does a thread enter when it terminates its processing?

When a thread terminates its processing, it enters the dead state.

13. What is the Collections API?

The Collections API is a set of classes and interfaces that support operations on collections of objects.

14. Which characters may be used as the second character of an identifier, but not as the first character of an identifier?

The digits 0 through 9 may not be used as the first character of an identifier but they may be used after the first character of an identifier.

15. What is the List interface?

The List interface provides support for ordered collections of objects.

16. How does Java handle integer overflows and underflows?

It uses those low order bytes of the result that can fit into the size of the type allowed by the operation.

17. What is the Vector class?

The Vector class provides the capability to implement a growable array of objects

18. What modifiers may be used with an inner class that is a member of an outer class?

A (non-local) inner class may be declared as public, protected, private, static, final, or abstract.

19. What is an Iterator interface?

The Iterator interface is used to step through the elements of a Collection.

20. What is the difference between the >> and >>> operators?

The >> operator carries the sign bit when shifting right. The >>> zero-fills bits that have been shifted out.

To Be Contiued.....

Intelligent Question

Monday, October 5, 2009

Answer:

Search Engine Giants Goole And Bing.

Friday, October 2, 2009

This year Microsoft launched Bing, a search engine that as far as anyone can see, was designed to compete with Google.

Bing does not use the same algorithms that Google does, and some experts think that Bing does not deliver the same kind of results that Google does.

Here are some of the differences that internet users will experience with Bing:

Bing will eliminate a number of duplicate results. The likely consequence of this is that pages that have lower rank will be shown in some categories.

When someone does a keyword search, results are shown as they are associated with general keywords. If your website has certain keyword combinations, your site will show up higher in the results. The likely consequence of this is that sites with good, quality content will do better in Bing searches.

Bing seems to favor results for general terms and shows more results per page.

If this remains true, then your chances of showing up at the top of Bing or Google or any other search engine will not be altered dramatically as long as you are keeping your website updated, using useful links and keeping up with relevant keywords.

Bing is different from SEO's biggest player, Google, but there is no need for worry. Sound SEO practices carry over to all search engines because these practices keep internet users and search engines interested. For example, if Bing's algorithms highlight the need for fresh, quality content. A website would need this to stay competitive no matter what.

Search

Airports from all around the world To Improve Your GK

Wednesday, September 30, 2009

Airports
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport. An airport consists of at least one surface such as a runway, a helipad, or water for takeoffs and landings, and often includes buildings such as hangars and terminal buildings.

Larger airports may have fixed base operator services, seaplane docks and ramps, air traffic control, passenger facilities such as restaurants and lounges, and emergency services. A military airport is known as an airbase or air station. The terms airfield, airstrip, and aerodrome may also be used to refer to airports, and the terms heliport, seaplane base, and STOLport refer to airports dedicated exclusively to helicopters, seaplanes, or short takeoff and landing aircraft. In some jurisdictions, the term airport is used where the facility is licensed as such by the relevant government organization. Elsewhere the distinction is one of general appearance. Other jurisdictions define an airport by its having the customs offices etc expected of a port, though the more general term is airport of entry.

C Program Aptiude Questions

Friday, September 18, 2009

1)struct aaa{
struct aaa *prev;
int i;
struct aaa *next;
};
main()
{
struct aaa abc,def,ghi,jkl;
int x=100;
abc.i=0;abc.prev=&jkl;
abc.next=&def;
def.i=1;def.prev=&abc;def.next=&ghi;
ghi.i=2;ghi.prev=&def;
ghi.next=&jkl;
jkl.i=3;jkl.prev=&ghi;jkl.next=&abc;
x=abc.next->next->prev->next->i;
printf("%d",x);
}
Answer:
2
Explanation:
above all statements form a double circular linked list;
abc.next->next->prev->next->i
this one points to "ghi" node the value of at particular node is 2.

2) struct point
{
int x;
int y;
};
struct point origin,*pp;
main()
{
pp=&origin;
printf("origin is(%d%d)\n",(*pp).x,(*pp).y);
printf("origin is (%d%d)\n",pp->x,pp->y);
}

Answer:
origin is(0,0)
origin is(0,0)
Explanation:
pp is a pointer to structure. we can access the elements of the structure either with arrow mark or with indirection operator.
Note:
Since structure point is globally declared x & y are initialized as zeroes

3) main()
{
int i=_l_abc(10);
printf("%d\n",--i);
}
int _l_abc(int i)
{
return(i++);
}
Answer:
9
Explanation:
return(i++) it will first return i and then increments. i.e. 10 will be returned.

4) main()
{
char *p;
int *q;
long *r;
p=q=r=0;
p++;
q++;
r++;
printf("%p...%p...%p",p,q,r);
}
Answer:
0001...0002...0004
Explanation:
++ operator when applied to pointers increments address according to their corresponding data-types.

5) main()
{
char c=' ',x,convert(z);
getc(c);
if((c>='a') && (c<='z'))
x=convert(c);
printf("%c",x);
}
convert(z)
{
return z-32;
}
Answer:
Compiler error
Explanation:
declaration of convert and format of getc() are wrong.

6) main(int argc, char **argv)
{
printf("enter the character");
getchar();
sum(argv[1],argv[2]);
}
sum(num1,num2)
int num1,num2;
{
return num1+num2;
}
Answer:
Compiler error.
Explanation:
argv[1] & argv[2] are strings. They are passed to the function sum without converting it to integer values.

7) # include
int one_d[]={1,2,3};
main()
{
int *ptr;
ptr=one_d;
ptr+=3;
printf("%d",*ptr);
}
Answer:
garbage value
Explanation:
ptr pointer is pointing to out of the array range of one_d.

8) # include
aaa() {
printf("hi");
}
bbb(){
printf("hello");
}
ccc(){
printf("bye");
}
main()
{
int (*ptr[3])();
ptr[0]=aaa;
ptr[1]=bbb;
ptr[2]=ccc;
ptr[2]();
}
Answer:
bye
Explanation:
ptr is array of pointers to functions of return type int.ptr[0] is assigned to address of the function aaa. Similarly ptr[1] and ptr[2] for bbb and ccc respectively. ptr[2]() is in effect of writing ccc(), since ptr[2] points to ccc.

9) #include
main()
{
FILE *ptr;
char i;
ptr=fopen("zzz.c","r");
while((i=fgetch(ptr))!=EOF)
printf("%c",i);
}
Answer:
contents of zzz.c followed by an infinite loop
Explanation:
The condition is checked against EOF, it should be checked against NULL.

10) main()
{
int i =0;j=0;
if(i && j++)
printf("%d..%d",i++,j);
printf("%d..%d,i,j);
}
Answer:
0..0
Explanation:
The value of i is 0. Since this information is enough to determine the truth value of the boolean expression. So the statement following the if statement is not executed. The values of i and j remain unchanged and get printed.

11) main()
{
int i;
i = abc();
printf("%d",i);
}
abc()
{
_AX = 1000;
}
Answer:
1000
Explanation:
Normally the return value from the function is through the information from the accumulator. Here _AH is the pseudo global variable denoting the accumulator. Hence, the value of the accumulator is set 1000 so the function returns value 1000.

12) int i;
main(){
int t;
for ( t=4;scanf("%d",&i)-t;printf("%d\n",i))
printf("%d--",t--);
}
// If the inputs are 0,1,2,3 find the o/p
Answer:
4--0
3--1
2--2
Explanation:
Let us assume some x= scanf("%d",&i)-t the values during execution
will be,
t i x
4 0 -4
3 1 -2
2 2 0

13) main(){
int a= 0;int b = 20;char x =1;char y =10;
if(a,b,x,y)
printf("hello");
}
Answer:
hello
Explanation:
The comma operator has associativity from left to right. Only the rightmost value is returned and the other values are evaluated and ignored. Thus the value of last variable y is returned to check in if. Since it is a non zero value if becomes true so, "hello" will be printed.

14) main(){
unsigned int i;
for(i=1;i>-2;i--)
printf("c aptitude");
}
Explanation:
i is an unsigned integer. It is compared with a signed value. Since the both types doesn't match, signed is promoted to unsigned value. The unsigned equivalent of -2 is a huge value so condition becomes false and control comes out of the loop.

15) In the following pgm add a stmt in the function fun such that the address of
'a' gets stored in 'j'.
main(){
int * j;
void fun(int **);
fun(&j);
}
void fun(int **k) {
int a =0;
/* add a stmt here*/
}
Answer:
*k = &a
Explanation:
The argument of the function is a pointer to a pointer.

16) What are the following notations of defining functions known as?
i. int abc(int a,float b)
{
/* some code */
}
ii. int abc(a,b)
int a; float b;
{
/* some code*/
}
Answer:
i. ANSI C notation
ii. Kernighan & Ritche notation

17) main()
{
char *p;
p="%d\n";
p++;
p++;
printf(p-2,300);
}
Answer:
300
Explanation:
The pointer points to % since it is incremented twice and again decremented by 2, it points to '%d\n' and 300 is printed.

18) main(){
char a[100];
a[0]='a';a[1]]='b';a[2]='c';a[4]='d';
abc(a);
}
abc(char a[]){
a++;
printf("%c",*a);
a++;
printf("%c",*a);
}
Explanation:
The base address is modified only in function and as a result a points to 'b' then after incrementing to 'c' so bc will be printed.

19) func(a,b)
int a,b;
{
return( a= (a==b) );
}
main()
{
int process(),func();
printf("The value of process is %d !\n ",process(func,3,6));
}
process(pf,val1,val2)
int (*pf) ();
int val1,val2;
{
return((*pf) (val1,val2));
}
Answer:
The value if process is 0 !
Explanation:
The function 'process' has 3 parameters - 1, a pointer to another function 2 and 3, integers. When this function is invoked from main, the following substitutions for formal parameters take place: func for pf, 3 for val1 and 6 for val2. This function returns the result of the operation performed by the function 'func'. The function func has two integer parameters. The formal parameters are substituted as 3 for a and 6 for b. since 3 is not equal to 6, a==b returns 0. therefore the function returns 0 which in turn is returned by the function 'process'.

20) void main()
{
static int i=5;
if(--i){
main();
printf("%d ",i);
}
}
Answer:
0 0 0 0
Explanation:
The variable "I" is declared as static, hence memory for I will be allocated for only once, as it encounters the statement. The function main() will be called recursively unless I becomes equal to 0, and since main() is recursively called, so the value of static I ie., 0 will be printed every time the control is returned.