What is an interrupt? Part-1



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The concept of “Interrupt” is purely based on common-sense. To give you an example, imagine a parallel port in your PC being connected to a printer. During a print operation in progress, the CPU supplies characters to the parallel port (to be passed onto the printer) at a periodic rate. Say, the parallel port runs out of data after printing 1000 characters. Now the parallel port starts to “starve” for more characters. The processors job is to identify the hungry parallel port and feed it with more characters. Here comes the concept of “interrupt”.

“Interrupt” is a signal used by an I/O device (like a parallel port) to inform the CPU that it has to feed the parallel port with more characters. As soon as the interrupt signal (an output of the I/O device) is received, the processor devotes it’s attention towards the corresponding I/O device. In the above example, the CPU then does a “write” operation to the parallel port.

Similarly, an interrupt could be signalled by an I/O device (say a floppy disk-controller) indicating that it is completely filled with data and hence the CPU may initiate a “read” operation, to retrieve the data.

Usually, the microprocessors have only one input request line. Hence it is not possible to connect all the interrupt request lines from various I/O devices directly to this single input. They are rather connected to a device called interrupt controller.

How does the interrupt-signaling process occur?

Continue reading “What is an interrupt? Part-1”

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Shyam Benegal’s Welcome to Sajjanpur


 

 

          They say, laughter is the best medicine; they also say good films help producers laugh all the way to the bank. But here’s one filmmaker you would have least expected to see to make comic capers.

Yes, it is Shyam Benegal who now seems raring to attempt a genre he’s hardly ever ventured into during his illustrious career. “This is the time when people seem to appreciate comic satires and all that. It appears to be the right kind of time to make a comedy,” said Shyam Benegal.

And his directorial first in comedy will be “Welcome to Sajjanpur”–a movie thats rather high on some heavy duty rustic humour.

“I think you better see the film. It’s going to take another 2 and a half weeks to get it released. That’s not long to go”, Shyam Benegal.

For Benegal who is better known for his films like Manthan, Sardari Begum and ZUbeida, films that are a tad removed from commercial sensibilities and compromises. Welcome to Sajjanpur is indeed a huge deviation.

Clearly the lines that divide parallel and mainstream cinema is blurring and considerably at that!

Read more on: http://www.timesnow.tv/NewsDtls.aspx?NewsID=14760

New Internet Explorer 8 Beta- What’s New?



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Six months after Beta 1 hit the streets, Microsoft releases Internet Explorer 8 Beta 2 to brave testers. The new beta includes features that make it look like a viable choice of modern browser, like a smart address bar (sound familiar?), tab grouping, private browsing, find in-page, suggested sites related to the current page, and more. Let’s take a look at what’s coming out of Redmond in the browser arena.

IE8 Beta 2’s Most Useful Features
Smart Address Bar: IE 8 beta 2 includes a Smart Address Bar, that, like Firefox 3’s “AwesomeBar,” drops down suggestions as-you-type a web site URL gleaned from your favorites, feeds, and history. Unlike Firefox, IE 8 includes headers so you can see where each suggestion comes from.

Tab Grouping: Ever open a bunch of links from a single page in new tabs, and then lose track of which tabs came from what page? IE8’s got a nifty “tab grouping” feature that colors your tabs based on their source. Here’s what a few tab groups—one from Lifehacker, one from the MSN homepage—look like.

InPrivate Browsing: What with the Smart Address Bar pulling up every site you’ve visited recently in plain view in its History suggestions, there may be times when you visit a site and have the browser forget it ever happened. IE 8 beta 2’s “InPrivate” browsing mode adds an icon to the address bar, and forgets you were ever at a web page when it’s enabled.

Continue reading “New Internet Explorer 8 Beta- What’s New?”