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Showing posts from 2007

Network Hardware Components

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Network Interface Card:- A network card, network adapter or NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network. It provides physical access to a networking medium and often provides a low-level addressing system through the use of MAC addresses. It allows users to connect to each other either by using cables or wirelessly. Repeaters:- A repeater is an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances without degradation. Because repeaters work with the actual physical signal, and do not attempt to interpret the data being transmitted, they operate on the Physical layer, the first layer of the OSI model. Hubs:- A hub contains multiple ports. When a packet arrives at one port, it is copied to all the ports of the hub. When the packets are copied, the destination address in the fram...

Computer Network

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A computer network is an interconnection of a group of computers. Networks may be classified by what is called the network layer at which they operate according to basic reference models considered as standards in the industry such as the four-layer Internet Protocol Suite model. While the seven-layer Open Systems Interconnection (OSI) reference model is better known in academia, the majority of networks use the Internet Protocol Suite (IP) as their network model. Types of networks: Personal Area Network (PAN):- A personal area network (PAN) is a computer network used for communication among computer devices close to one person. Some examples of devices that may be used in a PAN are printers, fax machines, telephones, PDAs, or scanners. The reach of a PAN is typically within about 20-30 feet (approximately 4-6 Meters). PANs can be used for communication among the individual devices (intrapersonal communication), or for connecting to a higher level network and the Internet (an uplink). ...
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Monitor A computer display monitor, usually called simply a monitor, is a piece of electrical equipment which displays viewable images generated by a computer without producing a permanent record. The word "monitor" is used in other contexts; in particular in television broadcasting, where a television picture is displayed to a high standard. A computer display device is usually either a cathode ray tube or some form of flat panel such as a TFT LCD Modem Modem (from modulate and demodulate) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio.

Wireless parts of a Computer

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Wireless Keyboard. A Wireless Keyboard is a keyboard that utilizes Bluetooth technology to communicate with the CPU instead of connecting via a plug-in cord. They also need batteries, most often 4 AA batteries, in order to operate. The operational range varies depending on the specific device. Wireless Mouse. A Wireless Mouse is a computer mouse that communicates with the CPU via Bluetooth technology instead of via a plug-in cord. The operational range varies depending on the model and they usually operate on 2 AA batteries. Wireless Joystick. A lever that moves in all directions and controls the movement of a pointer or some other display symbol. A joystick is similar to a mouse , except that with a mouse the cursor stops moving as soon as you stop moving the mouse. With a joystick, the pointer continues moving in the direction the joystick is pointing. To stop the pointer, you must return the joystick to its upright position. Most joysticks include two buttons called triggers...
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Google Developing Mobile OS Google has been throwing around the possibility of a mobile OS for quite some time now, although there's been stirs of an announcement coming after Labor Day. This all started with Google's acquisition of mobile software company Android, founded by Andy Rubin. Andy has continued to developed a Linux based mobile OS, which they've shown to several mobile phone makers. It sounds as if Google is outsourcing all the hardware work, and mainly concerning themselves with a highly customizable system with Google integration . Windows Moble OS The definitive reference guide for Windows Mobile 6.0 has been released. The guide details the differences and advantages of Windows Mobile 6.0 - and what’s up with all those crazy new names. So, if you just have to know everything about the new mobile OS offering from Microsoft, go download the PDF file today! Just be warned, the Windows Mobile 6.0 Product Reference Guide caters to mobile operators, OEM’s, IT prof...

Computer - Data Storage Devices

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BLU-RAY DISK(BD) A Blu-ray Disc (also called BD) is a high-density optical disc format for the storage of digital information, including high-definition video. The name Blu-ray Disc is derived from the blue-violet laser used to read and write this type of disc. Because of its shorter wavelength (405 nm), substantially more data can be stored on a Blu-ray Disc than on the DVD format, which uses a red (650 nm) laser. A single layer Blu-ray Disc can store 25 gigabytes (GB), over five times the size of a single layer DVD at 4.7 GB. USB Flash Drive USB flash drives are NAND-type flash memory data storage devices integrated with a USB (universal serial bus) interface. They are typically small, lightweight, removable and rewritable.USB flash drives offer potential advantages over other portable storage devices, particularly the floppy disk. They are more compact, faster, hold more data, and are more reliable due to their lack of moving parts, and more durable design.
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Floppy Disk Drives / Floppy Disks Floppy disk drives were originally introduced commercially as a read-only device in the early 1970s. These early floppy disk drives were used to hold microcode and diagnostics for large IBM mainframe computer systems. These disk drives were using 8-inch floppy diskettes recorded on only one side. By changing these diskettes inside the floppy drive, technicians could easily update the microcode to the latest revisions or load diagnostics easily. The storage capacity of these early readonly drives was less than 100 kilobytes. In 1973 a new upgraded 8 inch drive with read/write capability and a capacity of about 250 kilobytes began shipping which IBM used in data entry systems. This drive incorporated many technical improvements and became a model for drives still in use today. As time went on, designers learned how to reliably record on both sides of the diskette as well as increase the density of the data recorded on the diskette. Modern floppy drives ...