Tuesday, May 29, 2007

American carrom

American carrom is an alternative on carrom derived in America by missionaries to the East, around 1890. Believing that the game required restructuring for Western tastes, a Sunday school teacher named Henry Haskell altered the game. Much of the game is the same, but the striker's weight is reduced and the carrom men are smaller. Generally, instead of disks of solid wood, ivory, or acrylic, carrom men are rings, originally of wood but today commercially made of light plastic. In addition, as an alternative to using the fingers to flick the striker,American carrom uses miniature cue sticks. American carrom boards also have pockets built into the corners, rather than circular holes in the board, to make pocketing easier. While traditionally made boards vary widely, current commercially-produced American carrom boards are 28 inches square, are printed with checkerboard and backgammon patterns, among others, and are sold with checkers, chess pieces, skittles, etc., to allow other games to be played on the same board. Often, these boards are also built to play crokinole.

Monday, May 21, 2007


A joystick is a personal computer tangential or general control device consisting of a handheld stick that pivots about one end and transmits its angle in two or three dimensions to a computer. Joysticks are often used to control video games, and generally have one or more push-buttons whose state can also be read by the computer. The term joystick has become a synonym for game controllers that can be connected to the computer since the computer defines the input as a "joystick input”. Apart for controlling games; joysticks are also used for controlling machines such as elevators, cranes, trucks, powered wheelchairs and some zero turning radius lawn mowers. More lately miniture joysticks have been adopted as navigational devices for smaller electronic apparatus such as mobile phones.

Tuesday, May 15, 2007


In chemistry, a metal is a constituent that readily loses electrons to form positive ions and has metallic bonds between metal atoms. Metals form ionic bonds with non-metals. They are sometimes described as a web of positive ions surrounded by a cloud of delocalized electrons. The metals are one of the three groups of elements as eminent by their ionization and bonding properties, along with the metalloids and nonmetals. On the periodic table, a diagonal line drawn from boron separates the metals from the nonmetals. Most elements on this line are metalloids, sometimes called semi-metals; elements to the lower left are metals; elements to the upper right are nonmetals.

A modern definition of metals is that they have overlapping conveyance bands and valence bands in their electronic structure. This definition opens up the category for metallic polymers and other organic metals, which have been prepared by researchers and employed in high-tech devices. These synthetic materials often have the characteristic silvery-grey reflective ness of elemental metals.

Wednesday, May 09, 2007

Hard Disk

A hard disk is a non-volatile storage device which stores digitally programmed data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to a device that drives (removable) media, such as a tape drive or (floppy) disk drive, although a hard disk contains fixed (non-removable) media. Recently the hard disk has become more commonly known as the "hard drive".

Hard disks were initially developed for use with computers. In the 21st century, applications for hard disks have extended beyond computers to consist of digital video recorders, digital audio players, personal digital assistants, digital cameras, and video game consoles. In 2005 the first mobile phones to contain hard disks were introduced by Samsung Group and Nokia. The need for large-scale, reliable storage, independent of a particular device, led to the beginning of configurations such as RAID, hardware such as network attached storage (NAS) devices, and systems such as storage area networks (SANs) for efficient access to large volumes of data.

Thursday, May 03, 2007

History of Personal computer

An near the beginning use of the term appeared in a November 3, 1962, New York Times
article exposure John W. Mauchly's vision of expectations computing spoken to a conference of the American Institute of Industrial Engineers that previous day. Mauchly told the gathering, "There is no reason to suppose the average boy or girl cannot be master of a personal computer."

The initial computers that can be called 'personal' were the first Non -main frame computers, the LINC and the PDP-8. By today's standards they were big, expensive, and had small magnetic core memories.

However, they were small and cheap for individual laboratories and research projects to use, freeing them from the consignment dispensation and establishment of the typical industrial or university computing center. In addition, they were reasonably interactive and soon had their own operating systems. Finally, this category became known as the mini-computer, usually with time-sharing and program development facilities. Ultimately, the mini-computer grew up to encompass the VAX and larger mini-computers from Data General, Prime, and others.
Deployment of mini-computer systems was a replica for how personal computers would be used, but few of the mini-computer makers managed to profit from it.