Hello everyone
I wanted to know what is FSB? what are its physical significance & where is it located??
it would be quite helpful for me to undertsand FSB if any of u posts the answer of my doubts
Monday, August 2, 2010
PARITY BIT
PARITY BIT is a bit that is added to ensure that the number of bits is even or odd.
There are 2 types of parity bits:
1. Even parity bit
2. Odd parity bit
EVEN PARITY BIT
In the even parity if in a data for e.g. no of bit 8 ,the no of occurence of 1's is odd no of times, then we add 1 to it making entire set of bit even and making overall bit =9
e.g. 10001001 (1 occuring 3 times)
110001001 (even parity)
and if the occurence of 1's is even no of times then we add a zero to make it even.
e.g 10001101 (1 occuring 4 times)
010001101 (even parity)
ODD PARITY BIT
In the odd parity , if data bit consists of odd no of 1's we add a zero to it to make it odd.
e.g. 10001001(1 occuring 3 times)
010001001 (odd parity)
similarly if data bit consists of even no of 1's we add a 1 to make it odd.
e.g. 10001101(1 occuring 4 times)
110001101 (odd parity)
Even parity is a special case of a cyclic redundancy check (CRC), where the 1-bit CRC is generated by the polynomial x+1.
If the parity bit is present but not used, it may be referred to as mark parity (when the parity bit is always 1) or space parity (the bit is always 0).
(i hope you like the post. suggestions to improve and include more content clearly is welcomed)
There are 2 types of parity bits:
1. Even parity bit
2. Odd parity bit
EVEN PARITY BIT
In the even parity if in a data for e.g. no of bit 8 ,the no of occurence of 1's is odd no of times, then we add 1 to it making entire set of bit even and making overall bit =9
e.g. 10001001 (1 occuring 3 times)
110001001 (even parity)
and if the occurence of 1's is even no of times then we add a zero to make it even.
e.g 10001101 (1 occuring 4 times)
010001101 (even parity)
ODD PARITY BIT
In the odd parity , if data bit consists of odd no of 1's we add a zero to it to make it odd.
e.g. 10001001(1 occuring 3 times)
010001001 (odd parity)
similarly if data bit consists of even no of 1's we add a 1 to make it odd.
e.g. 10001101(1 occuring 4 times)
110001101 (odd parity)
Even parity is a special case of a cyclic redundancy check (CRC), where the 1-bit CRC is generated by the polynomial x+1.
If the parity bit is present but not used, it may be referred to as mark parity (when the parity bit is always 1) or space parity (the bit is always 0).
(i hope you like the post. suggestions to improve and include more content clearly is welcomed)
VIDEO CONVERTERS
Hello everyone
We all want to have movies or clips on our cell phones but most of us have video clips(in 3 gp) with an awful quality. Imagine hearing some bollywood song in 3gp,it emits a creaking sound here is a solution-
first of all look into your phone's manual and find what are the video formats supported and what is your screen resolution.
if you love to watch clips or songs on your cell log on to www.effectmatrix.com and download total video converter. It is an excellent converter which gives superb video aand audio quality.import files and convert them.You can set the quality screen size etc,if not sure jast select your phone model(if nokia and sony),explore the options.Movies take a lot of time to convert so you have to compromise with quality,just use freez 3gp converter avaliable on smallvideosoft.com,believe me its the fastest . I have converted a whole dvd by freez in just 38 min 25 seconds !!
Endianness
Before i start with this post, i would like to share with my friends that this my first experience at bloging or any sort of posting on the net, i hope it is worth your precious time....
Endianness deals with integer representation in a computer . Now, we all know that there are certain human languages that are read from left to right like English,Hindi and then there are some languages like Arabic that are read from right to left.Similarly, integers are represented as sequence of bytes with the most significant byte on the left(The Big Endian),in some representations, while in others it is placed on the right(The little Endian).
Now lets see the main advantage of the two systems:-
1)The little Endian system has the property that the same value can be read from the memory at different lengths... Therefore, the value read from 32-bit memory can be read from the same address as either 16-bit memory or 8-bit memory. all of which retain the same numeric value.
2)The big Endian representation helps to obtain an approximation of the multi-byte value by reading the most significant portion instead of the complete representation.
Address Big-Endian representation of 1025 Little-Endian representation of 1025
00 00000000 00000001
01 00000000 00000100
02 00000100 00000000
03 00000001 00000000
For moe info, you can use the following links:-
http://en.wikipedia.org/wiki/Endianness
http://3bc.bertrand-blanc.com/endianness05.pdf
Endianness deals with integer representation in a computer . Now, we all know that there are certain human languages that are read from left to right like English,Hindi and then there are some languages like Arabic that are read from right to left.Similarly, integers are represented as sequence of bytes with the most significant byte on the left(The Big Endian),in some representations, while in others it is placed on the right(The little Endian).
Now lets see the main advantage of the two systems:-
1)The little Endian system has the property that the same value can be read from the memory at different lengths... Therefore, the value read from 32-bit memory can be read from the same address as either 16-bit memory or 8-bit memory. all of which retain the same numeric value.
2)The big Endian representation helps to obtain an approximation of the multi-byte value by reading the most significant portion instead of the complete representation.
Address Big-Endian representation of 1025 Little-Endian representation of 1025
00 00000000 00000001
01 00000000 00000100
02 00000100 00000000
03 00000001 00000000
For moe info, you can use the following links:-
http://en.wikipedia.org/wiki/Endianness
http://3bc.bertrand-blanc.com/endianness05.pdf
Blu-ray Discs
Blu-ray discs are optical storage media and look similar to regular CD/DVDs (they are all of the same size). But they can store 10 times the data in a single DVD.
NA = nsinθ ; n = refractive index. Since θ1>θ2, NA(BD) > NA(DVD)
The name "Blu-ray" comes from the blue laser being used to read and write. There are GaN (Gallium Nitride) diodes that produce photons of 405nm directly. 400nm is the wavelength of the violet component of the visible spectrum so the "blue laser" actually appears violet to the human eye. By decreasing the wavelength from 650 and 780nm used for DVDs and CDs respectively, and increasing the aperture from 0.60 to 0.85, the laser can be focused to a smaller area. Hence, more data can be stored in the same amount of space.
In BDs, the distance between the surface of the disk and the surface upon which the data is actually recorded is 0.1mm. This is 1/6 times the distance for a regular DVD. Since the discs are made of plastic, the incident angles can change a little due to disc warping. To check this problem, the NA is increased (to an extent) and the cover layer's thickness is decreased.
Cover layer thickness is reduced to check distortion of the laser spot.
Typical BDs can store 25GB if they are single layered, and 50GB if they are double layered.
"Double-layered" refers to the presence of two recording layers inside the protective cover layer. Each recording layer can store 25GB of data. Pioneer Corp. recently developed a BD with 20 recording layers which allows it to store 500GB of information inside a single BD!
Structure of single-side, double-layer BD
NA = nsinθ ; n = refractive index. Since θ1>θ2, NA(BD) > NA(DVD)The name "Blu-ray" comes from the blue laser being used to read and write. There are GaN (Gallium Nitride) diodes that produce photons of 405nm directly. 400nm is the wavelength of the violet component of the visible spectrum so the "blue laser" actually appears violet to the human eye. By decreasing the wavelength from 650 and 780nm used for DVDs and CDs respectively, and increasing the aperture from 0.60 to 0.85, the laser can be focused to a smaller area. Hence, more data can be stored in the same amount of space.
In BDs, the distance between the surface of the disk and the surface upon which the data is actually recorded is 0.1mm. This is 1/6 times the distance for a regular DVD. Since the discs are made of plastic, the incident angles can change a little due to disc warping. To check this problem, the NA is increased (to an extent) and the cover layer's thickness is decreased.
Cover layer thickness is reduced to check distortion of the laser spot.Typical BDs can store 25GB if they are single layered, and 50GB if they are double layered.
"Double-layered" refers to the presence of two recording layers inside the protective cover layer. Each recording layer can store 25GB of data. Pioneer Corp. recently developed a BD with 20 recording layers which allows it to store 500GB of information inside a single BD!
Structure of single-side, double-layer BDAnd finally, regarding the popularity of BDs, they are mostly used to store HD videos since the regular DVDs can only store Standard Definition (SD) videos. When HDTVs become widespread, BDs are expected to replace DVDs. For the time being, companies such as Sony, Panasonic, Phillips, Samsung, Pioneer and LG have developed BD drives that are compatible with BDs and DVDs both. This is known as Backward Compatibility and is a measure to ensure that once newer media like BDs become popular, the older storage media do not become obsolete.
Photographs courtesy : http://panasonic.net/blu-ray/technology/
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