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Centronics Printer Port
IEEE 1284 is a standard that defines bi-directional parallel communications between computers and other devices. It was originally developed in the 1970s by Centronics, and was widely known as the Centronics port, both before and after its IEEE standardization. History In the 1970s, Centronics developed the now-familiar printer parallel port that soon became a ''de facto'' standard. Centronics had introduced the first successful low-cost seven-wire print head, which used a series of solenoids to pull the individual metal pins to strike a ribbon and the paper. A dot matrix print head consists of a series of metal pins arranged in a vertical row. Each pin is attached to some sort of actuator, a solenoid in the case of Centronics, which can pull the pin forward to strike a ribbon and the paper. The entire print head is moved horizontally in order to print a line of text, striking the paper several times to produce a matrix for each character. Character sets on early printer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Communications
In data transmission, parallel communication is a method of conveying multiple binary digits (bits) simultaneously using multiple conductors. This contrasts with serial communication, which conveys only a single bit at a time; this distinction is one way of characterizing a communications link. The basic difference between a parallel and a serial communication channel is the number of electrical conductors used at the physical layer to convey bits. Parallel communication implies more than one such conductor. For example, an 8-bit parallel channel will convey eight bits (or a byte) simultaneously, whereas a serial channel would convey those same bits sequentially, one at a time. If both channels operated at the same clock speed, the parallel channel would be eight times faster. A parallel channel may have additional conductors for other signals, such as a clock signal to pace the flow of data, a signal to control the direction of data flow, and handshaking signals. Parallel commu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IBM PS/2
The Personal System/2 or PS/2 is IBM's second generation of personal computers. Released in 1987, it officially replaced the IBM PC, XT, AT, and PC Convertible in IBM's lineup. Many of the PS/2's innovations, such as the 16550 UART (serial port), 1440 KB 3.5-inch floppy disk format, 72-pin SIMMs, the PS/2 port, and the VGA video standard, went on to become standards in the broader PC market. The PS/2 line was created by IBM partly in an attempt to recapture control of the PC market by introducing the advanced yet proprietary Micro Channel architecture (MCA) on higher-end models. These models were in the strange position of being incompatible with the IBM-compatible hardware standards previously established by IBM and adopted in the PC industry. However, IBM's initial PS/2 computers were popular with target market corporate buyers, and by September 1988 IBM reported that it had sold 3 million PS/2 machines. This was only 18 months after the new range had been introduced. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FireWire
IEEE 1394 is an interface standard for a serial bus for high-speed communications and isochronous real-time data transfer. It was developed in the late 1980s and early 1990s by Apple in cooperation with a number of companies, primarily Sony and Panasonic. Apple called the interface FireWire. It is also known by the brand names i.LINK (Sony), and Lynx (Texas Instruments). The copper cable used in its most common implementation can be up to long. Power and data is carried over this cable, allowing devices with moderate power requirements to operate without a separate power supply. FireWire is also available in Cat 5 and optical fiber versions. The 1394 interface is comparable to USB. USB was developed subsequently and gained much greater market share. USB requires a host controller whereas IEEE 1394 is cooperatively managed by the connected devices. History and development FireWire is Apple's name for the IEEE 1394 High Speed Serial Bus. Its development was initiated by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Port
In computing, a parallel port is a type of interface found on early computers (personal and otherwise) for connecting peripherals. The name refers to the way the data is sent; parallel ports send multiple bits of data at once ( parallel communication), as opposed to serial communication, in which bits are sent one at a time. To do this, parallel ports require multiple data lines in their cables and port connectors and tend to be larger than contemporary serial ports, which only require one data line. There are many types of parallel ports, but the term has become most closely associated with the printer port or Centronics port found on most personal computers from the 1970s through the 2000s. It was an industry ''de facto'' standard for many years, and was finally standardized as IEEE 1284 in the late 1990s, which defined the Enhanced Parallel Port (EPP) and Extended Capability Port (ECP) bi-directional versions. Today, the parallel port interface is virtually non-exis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IFSP
IFSP (german: Interface sternförmig parallel, russian: Интерфейс радиальный параллельный (ИРПР)), or radial parallel interface, was a parallel interface similar to the Centronics connector (IEEE 1284) but incompatible, as it had different signal polarities and handshake protocol. It was used in printers and computers manufactured in Comecon. All printer input signal lines were pulled up to +5V by a 220 Ohm resistor, and pulled down to ground by a 330 Ohm Ohm (symbol Ω) is a unit of electrical resistance named after Georg Ohm. Ohm or OHM may also refer to: People * Georg Ohm (1789–1854), German physicist and namesake of the term ''ohm'' * Germán Ohm (born 1936), Mexican boxer * Jörg Ohm (b ... resistor. This allowed usage of longer cables compared to Centronics, but overloaded most usual Centronics adapters. Some devices allowed switching between IFSP and Centronics modes, i.e. Robotron 6319—6329 were manufactured with interchangeable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Logic Level
In digital circuits, a logic level is one of a finite number of states that a digital signal can inhabit. Logic levels are usually represented by the voltage difference between the signal and ground, although other standards exist. The range of voltage levels that represent each state depends on the logic family being used. A '' logic-level shifter'' can be used to allow compatibility between different circuits. 2-level logic In binary logic the two levels are logical high and logical low, which generally correspond to binary numbers 1 and 0 respectively. Signals with one of these two levels can be used in boolean algebra for digital circuit design or analysis. Active state The use of either the higher or the lower voltage level to represent either logic state is arbitrary. The two options are active high and active low. Active-high and active-low states can be mixed at will: for example, a read only memory integrated circuit may have a chip-select signal that is active-low, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transistor–transistor Logic
Transistor–transistor logic (TTL) is a logic family built from bipolar junction transistors. Its name signifies that transistors perform both the logic function (the first "transistor") and the amplifying function (the second "transistor"), as opposed to earlier resistor–transistor logic (RTL) and diode–transistor logic (DTL). TTL integrated circuits (ICs) were widely used in applications such as computers, industrial controls, test equipment and instrumentation, consumer electronics, and synthesizers. After their introduction in integrated circuit form in 1963 by Sylvania Electric Products, TTL integrated circuits were manufactured by several semiconductor companies. The 7400 series by Texas Instruments became particularly popular. TTL manufacturers offered a wide range of logic gates, flip-flops, counters, and other circuits. Variations of the original TTL circuit design offered higher speed or lower power dissipation to allow design optimization. TTL devices were original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro Ribbon
The micro ribbon or miniature ribbon connector is a common type of electrical connector for a variety of applications, such as in computer and telecommunications equipment having many contacts. The connector contains two parallel rows of contacts within a shielded case having a characteristic D-shape similar to that used in D-subminiature connectors. The contacts are not pins, but small flat bands of metal, called ribbon contacts. The connectors are manufactured in many capacities, including 14-, 24-, 36-, 50-, 64-, and 100- pin varieties. They may be mounted on boards, panels, or may terminate cables. Wires are attached by means of solder, crimping or insulation displacement. Female connectors have bail locks for a sturdy connection to the male connector. Screws may also be employed to secure connections. This connector type is also known as ''telco'', ''25-pair'', ''miniature delta ribbon'', ''mini D ribbon'', ''delta ribbon'', ''MDR'', ''Amphenol'', or ''CHAMP'' min ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D-subminiature
The D-subminiature or D-sub is a common type of electrical connector. They are named for their characteristic D-shaped metal shield. When they were introduced, D-subs were among the smallest connectors used on computer systems. Description, nomenclature, and variants A D-sub contains two or more parallel rows of pins or sockets usually surrounded by a D-shaped metal shield that provides mechanical support, ensures correct orientation, and may screen against electromagnetic interference. D-sub connectors have gender: parts with pin contacts are called ''male connectors'' or ''plugs'', while those with socket contacts are called ''female connectors'' or ''sockets''. The socket's shield fits tightly inside the plug's shield. Panel mounted connectors usually have #4-40 UNC (as designated with the Unified Thread Standard) jackscrews that accept screws on the cable end connector cover that are used for locking the connectors together and offering mechanical strain relief, and ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_MSX_printer_port.jpg "Click for more on -> Micro Ribbon")
