Microprocessors

Newer processors from Intel (Prescott P4s, the Core 2 line, and later) don't have pins--the pins are actually in the socket; thus why they're called Land Grid Array setups. In these cases, the contact force is provided by a special cover (called a load plate) built into the socket. Once the processor is properly placed, the load plate flips on top of the processor and then secured by an arm.

In both scenarios, further securing force is provided by the cooling system (usually a heatsink and fan) that is placed on top of the processor. Socket designs specify how the cooling systems are to be secured to the motherboard. Their installation further secures the processor into the socket.

By using buffer along with micro-controller, it is possible to reduce the effect of 'back EMF' or 'Spiking Effect'. The capacity of any micro-controller is to sink or source current up to 25mA and its ports gets damaged if it is more. So buffer protects ports of micro-controller getting damaged. And it is possible to get appropriate data trans-receiving by using buffer in micro-controller.

Sachin Joshi

A computers top three parts according to the standards of PC's in 2008.

1]A motherboard comes first with the design around CPU and Memory with the video/sound/lan and tons of other parts automatically an essiential part of the package you purchase.

2]The HDD/DVD drives have finally seen new changes in both with the additions of BluRay High definition drive and solid state hard drives. These come in as number two because the last part is really a 2 step process.

3]Any operating system can be installed with the first two items in place. The latest version of Vista has almost crossed over as a full bodied platform when it comes to technology, but they still offer server software seperately. Other OS like Linux have all needed components to run as a PC or Server and a copy of Windows that is bootable(to boot).
The CPU has three main parts...

• The A.L.U. (Arithmetic and Logic Unit) which performs all the calculations.
• The Control Unit - which controls the flow of data round the computer by sending out control signals.
• Memory - which is used to store data.

Mask ROM (MROM) refers to a kind of ROM (read-only memory) whose contents are programmed by the integrated circuit manufacturer (rather than by the user). The terminology "mask" comes from integrated circuit fabrication, where regions of the chip are masked off during the process of photolithography.

It is common practice to use rewritable non-volatile memory - such as UV-EPROM or EEPROM - for the development phase of a project, and to switch to mask ROM when the code has been finalized. For example, Atmel microcontrollers come in both EEPROM and Mask ROM formats.

The main advantage of mask ROM is its cost. Per bit, mask rom is more compact than any other kind of semiconductor memory. Since the cost of an integrated circuit strongly depends on its size, mask ROM is significantly cheaper than any other kind of semiconductor memory.

However, the one-time masking cost is high and there is a long turn-around time from design to product phase. Design errors are costly: if an error in the data or code is found, the mask ROM is useless and must be replaced in order to change the code or data.

Some integrated circuits contain only mask ROM. As of 2003, four companies produce most such mask ROM chips: Samsung Electronics, NEC Corporation, Oki Electric Industry, and Macronix.[1]

Other integrated circuits contain mask ROM as well as a variety of other devices. In particular, many microprocessor chips include an area of mask ROM to store their microcode. Some microcontroller chips include an area of mask ROM to store the bootloader or all of their firmware.

Refresh your understanding of fraction sizes. Keep in mind that the larger the numerator, or top part, of a fraction, the larger it will be (2/4 is bigger than 1/4, for example). On the other hand, the larger the denominator, or bottom part, of a fraction, the smaller it will be (1/4 is smaller than 1/3).

• 2

Study the problem at hand and evaluate which fraction is easier to work with. When estimating with fractions you will have to combine two fractions in some way (usually addition, subtraction, multiplication or division). Fractions with smaller numerators, like 1/2, are usually easier to work with than fractions with larger numerators, like 1/8.

• 3

Start with the fraction that is easiest to work with, putting in terms of the harder fraction's denominator. To do this, multiply the top and the bottom by the same number until the bottom number matches the other fraction's denominator. For example, if you have 1/2 + 1/8, as in the previous step, you could change 1/2 to 4/8.

• 4

Change hard-to-visualize fractions, such as 1/27, into the closest number that's easier to work with, like 1/26. For estimating purposes, it's okay to overlook the difference. In this case, 26 is a better denominator because it's easier to convert when you're working with more than one fraction. For example, 1/2 is the same as 13/26.

• 5

Perform the required operation on the numbers. If adding the previous terms, for example, you would have 1/26+13/26. Adding them together, you arrive at 14/26.

• 6

Estimate the size of the fraction in relationship to 1 (one whole). You know that 1, in terms of 26, would be 26/26; therefore, you know that 14/26 is less than 1.

• 7

Estimate the size of the fraction in relationship to 1/2. In this case, 13/26 is 1/2, so 14/26 is slightly bigger than 1/2.

• 8

Reduce the fraction, dividing both the numerator and the denominator by the same number, in order to check your work. Here, 14 and 26 both have factors of 2; when divided by 2, you arrive at 7/13, which makes it easy to see that it's slightly more than 1/2.