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Farallon Computing
Netopia, Inc., formerly Farallon Computing, Inc., was an American computer networking company that produced a wide variety of products including bridges, repeaters and switches, and in their later Netopia incarnation, modems, routers, gateways, and Wi-Fi devices. The company also produced the NBBS (Netopia Broadband Server Software) and, as Farallon, Timbuktu remote administration software, as well as the MacRecorder, the first audio capture and manipulation products for the Macintosh (later sold to Macromedia). Farallon originated several notable technologies, including: * PhoneNet, an implementation of AppleTalk over plain ("Cat-3") telephone wiring or, more commonly, EIA-TIA 568A/B structured cabling systems. Many versions of the product were produced, but the original product was a commercialized version of a kit developed and produced by BMUG, the Berkeley Macintosh Users Group in 1986. * The StarController, a line of LocalTalk and Ethernet bridges and switches released ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mini-DIN Connector
The mini-DIN connectors are a family of multi-pin electrical connectors used in a variety of applications. Mini-DIN is similar to the larger, older 13.2 mm diameter DIN connector. Design Mini-DIN connectors are in diameter and come in seven patterns, with the number of pins from three to nine. Each pattern is keyed in such a way that a plug with one pattern cannot be mated with any socket of another pattern. They are each drastically different from the other, with no simultaneously and directly overlapping similarities in (1) pin arrangement, (2) square key size and position, (3) circular shielding metal skirt notches and metallic additions: in this they differ from the nonstandard mini-DIN connectors which may have directly overlapping characteristics to each other or to the standard mini-DIN connectors. Notable usage Some notable examples of standard mini-DIN connectors include: * Mini-DIN-3 connectors were used in early implementations of Apple LocalTalk. * Mini- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrier-sense Multiple Access With Collision Avoidance
Carrier-sense multiple access with collision avoidance (CSMA/CA) in computer networking, is a link layer multiple access method in which carrier sensing is used. Under CSMA/CA, nodes attempt to avoid collisions by beginning transmission only after the channel is sensed to have no traffic. When they do transmit, nodes transmit frames in their entirety. This technique is primarily used in wireless networks, where the alternative with collision detection CSMA/CD is not possible due to wireless transmitters de-sensing (turning off) their receivers during packet transmission. CSMA/CA is unreliable due to the hidden node problem. Details Collision avoidance is used to improve the performance of the CSMA method by attempting to divide the channel somewhat equally among all transmitting nodes within the collision domain. # Carrier Sense: prior to transmitting, a node first listens to the shared medium (such as listening for wireless signals in a wireless network) to determine whet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethernet
Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1983 as IEEE 802.3. Ethernet has since been refined to support higher bit rates, a greater number of nodes, and longer link distances, but retains much backward compatibility. Over time, Ethernet has largely replaced competing wired LAN technologies such as Token Ring, FDDI and ARCNET. The original 10BASE5 Ethernet uses a thick coaxial cable as a shared medium. This was largely superseded by 10BASE2, which used a thinner and more flexible cable that was both less expensive and easier to use. More modern Ethernet variants use Ethernet over twisted pair, twisted pair and fiber optic links in conjunction with Network switch, switches. Over the course of its history, Ethernet data transfer rates have been increased from the original to the lates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Port
A serial port is a serial communication Interface (computing), interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in Parallel communication, parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, computer terminal, terminals, various peripherals, and directly between computers. While interfaces such as Ethernet, FireWire, and USB also send data as a serial Stream (computing), stream, the term ''serial port'' usually denotes Computer hardware, hardware compliant with RS-232 or a related standard, such as RS-485 or RS-422. Modern consumer personal computers (PCs) have largely replaced serial ports with higher-speed standards, primarily USB. However, serial ports are still frequently used in applications demanding simple, low-speed interfaces, such as industrial automation sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase-locked Loop
A phase-locked loop or phase lock loop (PLL) is a control system that generates an output signal whose phase is fixed relative to the phase of an input signal. Keeping the input and output phase in lockstep also implies keeping the input and output frequencies the same, thus a phase-locked loop can also track an input frequency. Furthermore, by incorporating a frequency divider, a PLL can generate a stable frequency that is a multiple of the input frequency. These properties are used for clock synchronization, demodulation, frequency synthesis, clock multipliers, and signal recovery from a noisy communication channel. Since 1969, a single integrated circuit can provide a complete PLL building block, and nowadays have output frequencies from a fraction of a hertz up to many gigahertz. Thus, PLLs are widely employed in radio, telecommunications, computers (e.g. to distribute precisely timed clock signals in microprocessors), grid-tie inverters (electronic power converters used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daisy Chain (electrical Engineering)
In electrical and electronic engineering, a daisy chain is a wiring scheme in which multiple devices are wired together in sequence or in a ring, similar to a Daisy garland, garland of daisy flowers. Daisy chains may be used for power, analog signals, digital data, or a combination thereof. The term ''daisy chain'' may refer either to large scale devices connected in series, such as a series of power strips plugged into each other to form a single long line of strips, or to the wiring patterns embedded inside of devices. Other examples of devices which can be used to form daisy chains are those based on Universal Serial Bus (USB), FireWire, Thunderbolt (interface), Thunderbolt and Ethernet cables. Signal transmission For analog signals, connections usually consist of a simple Bus (computing), electrical bus and, especially in the case of a Signal chain (signal processing chain), chain of many devices, may require the use of one or more repeaters or amplifiers within the ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macintosh Plus
The Macintosh Plus computer is the third model in the Macintosh line, introduced on January 16, 1986, two years after the original Macintosh and a little more than a year after the Macintosh 512K, with a price tag of US$2,599. As an evolutionary improvement over the 512K, it shipped with 1 MB of RAM standard, expandable to 4 MB, and an external SCSI peripheral bus, among smaller improvements. Originally, the computer's case was the same beige color as the original Macintosh, Pantone 453; however, in 1987, the case color was changed to the long-lived, warm gray "Platinum" color. It is the earliest Macintosh model able to run System Software 5, System 6, and System 7, up to System 7.5.5, but not System 7.5.2. Overview Bruce Webster of ''BYTE'' reported a rumor in December 1985: "Supposedly, Apple will be releasing a Big Mac by the time this column sees print: said Mac will reportedly come with 1 megabyte of RAM ... the new 128K-byte ROM ... and a double-sided ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modular Connector
A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets. Modular connectors were originally developed for use on specific Bell System telephone sets in the 1960s, and similar types found use for simple interconnection of customer-provided telephone subscriber premises equipment to the telephone network. The Federal Communications Commission (FCC) mandated in 1976 an interface registration system, in which they became known as registered jacks. The convenience of prior existence for designers and ease of use led to a proliferation of modular connectors for many other applications. Many applications that originally used bulkier, more expensive connectors have converted to modular connectors. Probably the best-known applications of modular connectors are for telephone and Ethernet. Accordingly, various electronic interface specifications exis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Asynchronous Receiver-transmitter
A universal asynchronous receiver-transmitter (UART ) is a peripheral device for asynchronous serial communication in which the data format and transmission speeds are configurable. It sends data bits one by one, from the least significant to the most significant, framed by start and stop bits so that precise timing is handled by the communication channel. The electric signaling levels are handled by a driver circuit external to the UART. Common signal levels are RS-232, RS-485, and raw TTL for short debugging links. Early teletypewriters used current loops. It was one of the earliest computer communication devices, used to attach teletypewriters for an operator console. It was also an early hardware system for the Internet. A UART is usually implemented in an integrated circuit (IC) and used for serial communications over a computer or peripheral device serial port. One or more UART peripherals are commonly integrated in microcontroller chips. Specialised UARTs are use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
