Packet Switching ... Packet switching contrasts with another principal networking paradigm, circuit switching, a method which sets up a limited number of dedicated connections of constant bit rate and constant delay between nodes for exclusive use during the communication session. In case of traffic fees (as opposed to flat rate), for example in cellular communication services, circuit switching is characterized by a fee per time unit of connection time, even when no data is transferred, while packet switching is characterized by a fee per unit of information...
Personal Digital Assistant ... The first PDA was released in 1986 by Psion, the Organizer II. Followed by Psion's Series 3, in 1991, which began to resemble the more familiar PDA style...
Unconventional Computing ... Some mechanical computers have a theoretical or didactic relevance, such as billiard-ball computers or hydraulic ones,... Light (optical computing) Computers can manipulate information as light (rather than electricity or billiard balls)...
Colossus Computer ... The Colossus computers were used to help decipher teleprinter messages which had been encrypted using the Lorenz SZ40/42 machine—British codebreakers referred to encrypted German teleprinter traffic as "Fish" and called the SZ40/42 machine and its traffic "Tunny"...
Computer Program ... Computer source code is often written by computer programmers. Source code is written in a programming language that usually follows one of two main paradigms: imperative or declarative programming...
Programmer ... Computer programmers write, test, debug, and maintain the detailed instructions, called computer programs, that computers must follow to perform their functions...
Internet Protocol Suite ... The Internet protocol suite has four abstraction layers, each with its own protocols. From lowest to highest, the layers are: The link layer contains communication technologies for a local network...
Periphere Computer-Systeme ... In addition to UNIX computers, PCS also manufactured industrial terminals. Eventually, PCS was bought out by Mannesmann-Kienzle, which in turn was bought out by Ken Olsen to become part of DEC, Digital Equipment Corporation...
History Of Laptops ... Compaq SLT/286 By the end of the 1980s, laptop computers were becoming popular among business people...
Wi-Fi ... A device that can use Wi-Fi (such as a personal computer, video game console, smartphone, tablet, or digital audio player) can connect to a network resource such as the Internet via a wireless network access point. Such an access point (or hotspot) has a range of about 20 meters (65 feet) indoors and a greater range outdoors...
Personal Computer Hardware ... EISA Micro Channel architecture ISA: expansion card slot format obsolete in PCs, but still used in industrial computers... Most modern computers have hardware support for sound integrated in the motherboard chipset but some users prefer to install a separate sound card as an upgrade...
Microprocessor ... General-purpose microprocessors in personal computers are used for computation, text editing, multimedia display, and communication over the Internet...
Computer ... Conventionally a computer consists of some form of memory, at least one element that carries out arithmetic and logic operations, and a sequencing and control unit that can change the order of operations based on the information that is stored. Peripheral devices allow information to be entered from an external source, and allow the results of operations to be sent out...
Netbook ... More recently, Psion's now-discontinued netBook line, the OLPC XO-1 (initially called US$100 laptop) and the Palm Foleo were all small, portable, network-enabled computers...
Laptop ... As portable computers became smaller, lighter, cheaper, more powerful and as screens became larger and of better quality, laptops became very widely used for all sorts of purposes, by all sorts of people...
Software ... Computer software is so called to distinguish it from computer hardware, which encompasses the physical interconnections and devices required to store and execute (or run) the software. At the lowest level, execunguage consists of groups of binary values signifying processor instructions that change the state of the computer from its preceding state...