BlackBerry is most popular smartphone now a day. It is relased by Research In Motion which is usually called RIM in 1999. The BlackBerry Operating System is a software platform developed by its manufacturer RIM. Its OS provides multi-tasking that maximises use of the devices specialised platform including trackball, trackpad and touchscreen. This history starts like human history,step by step gets achievements. In Future, BlackBerry is looking very upbeat.
Wednesday, 26 February 2014
WhatsApp and Viber is allow user to exchange instant messages, shares videos,audios and images via Smartphone's. There has been rapid increase in online communication in the last 7-8 years, especially in mobile communication. Smartphone’s have taken up the market so well that everybody now can interact, socialize, and can share ideas and Information sitting at any corner in the world. Today’s young generation is busy in chatting and messaging every time with friends and with unknowns too. People are continuously exchanging information like images, videos, activities and events.
Tuesday, 25 February 2014
Android is an operating system based on the linux kernel and designed primarily for touchscreen mobile device such as smartphones and tablet computers. Initially developed by Android which Google backed finacially and later bought in 2005. Android is unveiled in 2007.
Android is popular with technology companies which require a ready-made, low cost and customizable opertating system for high-tech devices. Despite being primarily designed for phones and tablets, it also has been used in tv,games,digital camera and other electronics.
Subway Surfers is an endless action video game presented by Kiloo & Sybo Games. The player takes on the role of an average teen vandalizing a subway bus, and is caught by The Inspector and his dog. The player must run away from the police, who is chasing him/her. In the Sydney Update, they added Keys, which revives the character if they use them. The game is available on iOS and Android systems.
Launched in 2012, "World Tour" is the theme of the game, wherein cities like New York, Rio de Janeiro, Sydney, Rome, Tokyo and Miami have been featured till now. Available in iOS, Android platforms, the game features three default characters; Jake, Tricky and Fresh as they dash and dodge trains to escape from the grumpy inspector and his dog.
Monday, 24 February 2014
What is Network?
“A network is defined as two or more computers linked together for the purpose of communicating and sharing information and other resources”.
Basic Requirements of a Network:
Connections include the hardware (physical components) required to hook up a computer to the network. Two terms are important to network connections:
The network medium: The network hardware that physically connects one computer to another. This is the cable between the computers.
The network interface: The hardware that attaches a computer to the network medium and acts as an interpreter between the computer and the network. Attaching a computer to a network requires an add-in board known as a network interface card (NIC).
Communications establish the rules concerning how computers talk and understand each other. Because computers often run different software, in order to communicate with each other they must speak a "shared language." Without shared communications, computers cannot exchange information, and remain isolated.
A service defines those things a computer shares with the rest of the network. For example, a computer can share a printer or specific directories or files. Unless computers on the network are capable of sharing resources, they remain isolated, even though physically connected.
Types of Network:
There are two types of network.
LAN (LOCAL AREA NETWORK):
A LAN (local area network) is a network that covers a limited distance (usually a single site or facility) and allows sharing of information and resources. A LAN can be as simple as two connected computers, or as complicated as a large site. This type of network is very popular because it allows individual computers to provide processing power and utilize their own memory, while programs and data can be stored on any computer in the network. Some of the older LANs also include configurations that rely totally on the power of a mini or mainframe computer (a server) to do all the work. In this case, the workstations are no more than "dumb" terminals (a keyboard and a monitor). With the increased power of today's personal computer, these types of networks are rare.
WAN (Wide Area Networks):
A wide area network (WAN) spans relatively large geographical areas. Connections for these sites require the use of ordinary telephone lines, T1 lines, ISDN (Integrated Services Digital Network) lines, radio waves, or satellite links. WANs can be accessed through dial-up connections, using a modem, or leased line direct connection. The leased-line method is more expensive but can be cost-effective for transmission of large volumes of data.
Physical layout of network is called network topology.
There are three types of network.
Ring Topology Bus Topology Star Topology
In a star network, all devices are connected to a central point called a hub. These hubs collect and distribute the flow of data within the network. Signals from the sending computer go to the hub and are then transmitted to all computers on the network. Large networks can feature several hubs. A star network is easy to troubleshoot because all information goes through the hub, making it easier to isolate problems.
In a bus network, all devices are connected to a single linear cable called a trunk (also known as a backbone or segment). Both ends of the cable must be terminated (like a SCSI bus) to stop the signal from bouncing. Because a bus network does not have a central point, it is more difficult to troubleshoot than a star network. A break or problem at any point along the bus can cause the entire network to go down.
In a ring network, all workstations and servers are connected in a closed loop. There are no terminating ends; therefore, if one computer fails, the entire network will go down. Each computer in the network acts like a repeater and boosts the signal before sending it to the next station. This type of network transmits data by passing a "token" around the network. If the token is free of data, a computer waiting to send data grabs it, attaches the data and the electronic address to the token, and sends it on its way. When the token reaches its destination computer, the data is removed and the token sent on.
Network cable and connectors:
All networks need cables. The three main types are twisted-pair cable (TP), coaxial cable, and fiber-optic cable (FDDI—Fiber Distributed Data Interface).
Twisted-pair cable, shown in the picture consists of two insulated strands of copper wire twisted around each other to form a pair. One or more twisted pairs are used in a twisted-pair cable. The purpose of twisting the wires is to eliminate electrical interference from other wires and outside sources such as motors. By twisting the wires, any electrical noise from the adjacent pair will be canceled. The more twists per linear foot, the greater the effect.
Twisted-pair wiring comes in two types: shielded (STP) and unshielded (UTP). STP has a foil or wire braid wrapped around the individual wires of the pairs; UTP does not. The STP cable uses a woven-copper braided jacket, which is a higher-quality, more protective jacket than UTP.
Twisted pair cable
Of the two types, UTP is the most common. UTP cables can be further divided into five categories:
Category 1: Traditional telephone cable. Carries voice but not data.
Category 2: Certified UTP for data transmission of up to 4 Mbps (megabits per second). It has four twisted pairs.
Category 3: Certified UTP for data transmission of up to 10 Mbps. It has four twisted pairs.
Category 4: Certified UTP for data transmissions up to 16 Mbps. It has four twisted pairs.
Category 5: Certified for data transmissions up to 100 Mbps. It has four twisted pairs of copper wire.
Twisted-pair cable has several advantages over other types of cable (coaxial and fiber-optic)—it is readily available, easy to install, and inexpensive. Among its disadvantages are its sensitivity to EMI (electromagnetic interference) and susceptibility to eavesdropping; it does not support communication at distances of greater than 100 feet; and it requires the addition of a hub (a multiple network connection point) if it is to be used with more than two computers.
CAT5 Cabling Issues
Ethernet networks use unshielded twisted pair (UTP) Category 5 cable. CAT5 cable runs should not exceed 100 meters.
Coaxial cable is made of two conductors that share the same axis; the center is a copper wire that is insulated by a plastic coating and then wrapped with an outer conductor (usually a wire braid). This outer conductor around the insulation serves as electrical shielding for the signal being carried by the inner conductor. Outside the outer conductor is a tough insulating plastic tube that provides physical and electrical protection. At one time, coaxial cable was the most widely used network cabling. However, with improvements and the lower cost of twisted-pair cables, it has lost its popularity.
Coaxial cable is found in two types: thin (ThinNet) and thick (ThickNet). Of the two, ThinNet is the easiest to use. It is about one-quarter of an inch in diameter, making it flexible and easy to work with (it is similar to the material commonly used for cable TV). ThinNet can carry a signal about 605 feet (185 meters) before the signal strength begins to suffer. ThickNet, on the other hand, is about three-eighths of an inch in diameter. This makes it a better conductor—it can carry a signal about 1,640 feet (500 meters) before signal strength begins to suffer. The disadvantage of ThickNet over ThinNet is that it is more difficult to work with. The ThickNet version is also known as standard Ethernet cable.
When compared to twisted-pair, coaxial cable is the better choice even though it costs more. It is a standard technology that resists rough treatment and EMI. Although more resistant, it is still susceptible to EMI and eavesdropping.
Use coaxial cable if you need:
A medium that can transmit voice, video, and data.
To transmit data longer distances than less-expensive cabling.
A familiar technology that offers reasonable data security.
A Mixed-Cable System
Many networks use both twisted-pair and coaxial cable. Twisted-pair cable is used on a per-floor basis to run wires to individual workstations. Coaxial cable is used to wire multiple floors together. Coaxial cable should also be considered for a small network because you can purchase prefabricated cables (with end connectors installed) in various lengths.
Fiber-optic cable is made of light-conducting glass or plastic fibers. It can carry data signals in the form of modulated pulses of light. The plastic-core cables are easier to install, but do not carry signals as far as glass-core cables. Multiple fiber cores can be bundled in the center of the protective tubing.
When both material and installation costs are taken into account, fiber-optic cable can prove to be no more expensive than twisted-pair or coaxial cable. Fiber has some advantages over copper wire; it is immune to EMI and detection outside the cable and provides a reliable and secure transmission media. It also supports very high bandwidths (the amount of information the cable can carry), so it can handle thousands of times more data than twisted-pair or coaxial cable.
Cable lengths can run from .25 to 2.0 kilometers depending on the fiber-optic cable and network. If you need to network multiple buildings, this should be the cable of choice. Fiber-optic cable systems require the use of fiber-compatible NICs.
There are two different types of RJ-45 connectors. There is the "bent tyne" connector intended for use with solid core CAT5, and then there is the "aligned tyne" connector for use with stranded CAT5 cable. Errors have popped up when using incorrect cable/connector combinations. The "bent tyne" connector will work just fine on stranded wire by the way, just not the other way around. In general, make sure your connector matches you cable type...
Standards set forth by EIA/TIA 568A/568B and AT&T 258A define the acceptable wiring and color-coding schemes for CAT5 cables.
ST or Straight Connector
MTRJ Connector MTP Connector
Duplex SC Connector
There are two common types of fiber optic connectors: SC and ST. The ST or "straight tip" connector is the most common connector used with fiber optic cable, although this is no longer the case for use with Ethernet. It is barrel shaped, similar to a BNC connector, and was developed by AT&T. A newer connector, the SC, is becoming more and more popular. It has a squared face and is thought to be easier to connect in a confined space. The SC is the connector type found on most Ethernet switch fiber modules and is the connector of choice for 100Mbit and Gigabit Ethernet. A duplex version of the SC connector is also available, which is keyed to prevent the TX and RX fibers being incorrectly connected.
There are two more fiber connectors that we may see more of in the future. These are the MTRJ and MTP. They are both duplex connectors and are approximately the size of an RJ45 connector.
Network Interface Cards:
Network interface cards (NICs) link a computer to the network cable system. They provide the physical connection between the computer's expansion bus and the network cabling.
Installation of the network interface card is the same as for any other expansion card. It requires setup of the system resources: IRQ, address, and software. Most cards today allow connection
for either thin Ethernet or UTP (unshielded twisted-pair) cabling. Thin Ethernet uses a round BNC connector, and UTP uses a RJ-45 connector (similar to a telephone jack).
Network interface card
Installing a NIC is just like installing any other expansion card. If you are installing a Windows 95-compliant Plug and Play card in a Windows 95 or Windows 98 machine, you'll simply need to physically install the card and boot up the computer. The card will be detected and, more than likely, install itself. You might only need to answer a few questions along the way. It requires a little more work to install a NIC in an operating system that is not Plug and Play-compliant. Installing network cards includes the following steps:
Be sure to document any changes that you make to the existing computer. This will eliminate any confusion in the installation process and provide future reference in case of problems.
Determine whether the card needs IRQ, DMA (direct memory access), or address settings. Remember that you might have to configure these manually, so be sure to check the card's documentation for default settings and instructions for how to make any needed changes.
Determine whether the necessary settings are available on the machine on which they will be installed. If proper documentation is not available, use diagnostic software such as Microsoft Diagnostics (MSD) to determine settings. Also check your AUTOEXEC.BAT, CONFIG.SYS, and SYSTEM.INI files; they might give clues as to which settings are already in use.
Turn off the machine and remove the cover. Be sure to take all appropriate measures for protection against electrostatic discharge (ESD).
Set the NICs jumpers or DIPP (dual inline package) switches as necessary and insert the card.
Turn on the machine and run the setup utility provided by the manufacturer. If you are using Windows 95, Windows 98, or Windows 2000, and the NIC is not Plug and Play, you can use the Add New Hardware wizard in the Control Panel to install the drivers and set up the card. (Remember to document all settings.)
A network protocol is a set of rules that govern the way computers communicate over a network. In order for computers using different software to communicate, they must follow the same set of networking rules and agreements, called protocols. A protocol is like a language; unless both computers are speaking and listening in the same language, no communication will take place.
Networking protocols are grouped according to their functions, such as sending and receiving messages from the NIC, or talking to the computer hardware and making it possible for applications to function in a network. Early computer networks had manufacturer-unique inflexible hardware and strict protocols. Today's protocols are designed to be open, which means they are not vendor-, hardware-, or software-specific. Protocols are generically referred to as protocol families or protocol suites because they tend to come in groups (usually originating from specific vendors).
To see the network components, including protocols, which are associated with a network connection, open the Network Connections folder, right click, the connection, and select Properties.
Here are the components that XP/2000 installs by default:
To see the settings for a particular protocol, click the protocol and then click Properties.
By default, XP/2000 configures TCP/IP to obtain an IP address automatically. If there's a DHCP server on the network, it will assign the IP address and other TCP/IP settings to the connection. Otherwise, Windows XP/2000 will use Automatic Private IP Addressing to assign an IP address to the connection.
This default configuration should work, unchanged, to connect a Windows XP computer to a network that uses TCP/IP for File and Printer Sharing in these common configurations:
One computer on the network is running Internet sharing software, such as Internet Connection Sharing, and provides a DHCP server for assigning TCP/IP settings to the other computers.
A hardware router provides shared Internet access and a DHCP server.
All computers run either Windows 98, 98SE, Me, 2000, or XP, with no DHCP server. The computers can use Automatic Private IP Addressing to assign themselves compatible IP addresses.
Using an Internet sharing program or a hardware router protects the local area network from access by other Internet users, so it's safe to use TCP/IP for File and Printer Sharing on the LAN. The computers have private IP addresses that aren't accessible from the Internet. No other protocol is needed.
If your network uses static IP addresses, click Use the following IP address and enter the configuration information. For example, here are possible settings for a network that uses a proxy server at IP address 192.168.1.1 for Internet access.
Memory means to remember something in its mind. Think of memory as a vast bank of switches with two positions: on or off. Off is given the value of "0"; on is given the value of "1."
Computer’s memories are given below:
As computer technology advances, your computer will react more slowly, taking more time to process events. Luckily, computers can be easily upgraded. Upgrading your CPU (Central Processing Unit) is one of the most beneficial and easiest things you can do to make your computer run lag-free.
Take out your old CPU. Open up your case, un-clip the Heat-sink off the retaining board, and pull the the heat sink off. Some heat sinks require a screwdriver or other proprietary tool to remove.
Open the lever on the side of the socket. Do this by pulling it out, and then pulling it up. Gently lift your old CPU off of the socket.
Take the new CPU out of the box. Line up the gold triangle on the CPU with the one on the socket, and gently let the CPU fall in place. Do not force the CPU. If it is lined up correctly, it will drop right into place.
Close the ZIF (zero insertion force) lever to lock the CPU. Take the included heat-sink and clip it on using the instructions. If your heats-sink doesn't have thermal paste or pads on it yet, apply a very thin layer of it. If the heat-sink includes a fan, plug it into its proper connector. Do not operate a CPU without thermal transfer material or a heat-sink in place.
You have just installed your CPU! Power up and enjoy your upgraded computer.
It is intelligent buffer. A cache contains the data accessed between a slower peripheral device (RAM) and the faster CPU. Cache is high-speed memory than RAM. But cache quantity is slow.
There are two types of cache.
L1 Cache is made directly on the processor die. Therefore, the L1 cache always ran at the full speed of the chip that is CPU (microprocessor). It is also called internal cache.
L2 Cache on the motherboard is called second level cache ran at the slow speed of the motherboard. It is also called external cache.
“A collection of conducting wires which is responsible for communicating signals from one place to another place in a computer system.”
“A bus is a “highway” of digital signal it consist of a set of physical connection (printed circuit tracks and wires) over which the data and other information are moved for one place to another place”.
The address bus requests the memory location from the memory or I/O location from an I/O device. If an I/O is addressed, address bus contains 16-bit I/O address. The 16- bit I/O address selects one of the different I/O locations.
The data bus transfer the information between microprocessor and its memory an I/O locations. Data transfers vary in size depending upon the microprocessor.
The control bus contains lines that select the memory or I/O and cause them to perform read or write the operations.
Understanding Expansion Buses
Expansion cards are integrated circuit card that plug into an expansion slots on a motherboard to provide access to additional peripherals or features (such as video, sound, image capture cards, etc.) not built into the board. Also referred to as an add-in-board. Expansion slot is a slot on the motherboard that physically and electrically connects an expansion card to the motherboard and the system busses.
Today we use following buses which are use to transfer data:
The PCI bus specification was released in June 1992 as version 1.0 & since then have several upgrades.
The best features of the PCI slots are as bellow.
PCI cards do not have any jumpers, switches and are configured through the software.
PCI designs use special bus and chip set for advance bus mastering techniques. This allows to supports more than three PCI slots.
The PCI bus has its own set of Interrupts number for each slot, if a PC have more than four PCI slots, some of them will be sharing interrupts and IRQ,s
AGP version 2.0 was released in May 1998 and added 4X signaling as well as a lower 1.5v operation capability.
The latest version of AGP specification for PC,s is AGP 8X, which was announced in August 2000. It defines a faster 8x transfer mode for ever-greater performance than before. AGP command is found only on Pentium II and late computer systems The standard AGP 1x/2x, AGP 4x and AGP pro slots are compared to each other in the pictures.
AGP 4x and AGP pro can accept AGP 1x, 2x and 4x cards.
“To cool a system in which processor heat problem you can buy a special attachment for the CPU chip called a heat sink.”
When a computer system works, its processor consume power, therefore processor generate heat and this heat causes many problems for used to absorb heat on to the processor chip. Heat sink is made of a special metal, which carry heat away from the processor, data into fins. Fins that expose heat to moving air.
Types of Heat Sink:
There are two types of heat sink:
Passive Heat Sink:
The passive heat sinks for the socket processor showing a various attachment method and have no fan built into them.
Active Heat Sink:
The active heat sink for the processor have fan built into them.
The motherboard is usually the largest circuit board found inside the computer case. With out doubt, the most important component in a PC system is the main board or motherboard. Some companies refer to the motherboard as a system board or planar. The terms motherboard, main board, system board, and planar are interchange able. The function of the motherboard is to provide the connectivity for all devices (Input, Output, Storage), as well as for the CPU, RAM, and support ICs. It also defines the computer’s limits of speed, memory, and expandability. Figure shows the Structure and connectors of the motherboard.
Tuesday, 18 February 2014
A man can not be more than one place at the same time, but he has a friend he can get things done through him instead of doing them himself. If a man dies without fulfilling some desire, a friend can continue to make efforts to achieve that desire. A friend performs many offices for a man, such as praising him. A friend can suitably act in a situation which proves embarrassing to a man. A man may be hampered in a situation because he has to deal with close relatives. A friend working on his behalf, is free of such personal considerations.
Monday, 17 February 2014
A person who seeks to overcome his nature should set himself tasks which are neither too easy not nor difficult. Let him graduate from the easy to the more difficult. He should begin with external aids and go on with resolution to face situation which are more difficult than those he would usually face a man gains perfection, in this manner. When natural disposition is very strong, the process of subduing it must necessarily be slow and laborious. It is commendable if a man has the strength of mind and resolution to curb a disposition instantly and completely. Another good method to change one's disposition is to practise the opposite characteristic, provided, of course, it is not a vice.