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VT420
The VT420 is an ANSI standard computer terminal introduced in 1990 by Digital Equipment Corporation (DEC). The 420 is the only model in the 400 series, replacing the VT320. There are no color or graphics-capable 400 series terminals; the VT340 remained in production for those requiring ReGIS and Sixel graphics and color support. The entire lineup of VT300s and VT420 was eventually replaced by the relatively unknown VT500 series starting in 1993. Description The VT420 is essentially an updated VT320, adding the multi-session capabilities originally introduced on the VT330 and VT340. Those two models include a system known as TD/SMP which allows two sessions to be multiplexed over a single serial connection to a compatible terminal server. Alternately, the two sessions can be supported by separate serial connections on those models with multiple MMJ ports. Using either method, the VT330/340/420 can either show the two sessions behind each other, using a key sequence to flip back a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Replacement Character Set
The National Replacement Character Set (NRCS) was a feature supported by later models of Digital's (DEC) computer terminal systems, starting with the VT200 series in 1983. NRCS allowed individual characters from one character set to be replaced by one from another set, allowing the construction of different character sets on the fly. It was used to customize the character set to different local languages, without having to change the terminal's ROM for different countries, or alternately, include many different sets in a larger ROM. Many 3rd party terminals and terminal emulators supporting VT200 codes also supported NRCS. Description ASCII is a 7-bit standard, allowing a total of 128 characters in the character set. Some of these are reserved as control characters, leaving 96 printable characters. This set of 96 printable characters includes upper and lower case letters, numbers, and basic math and punctuation. ASCII does not have enough room to include other common characters s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VT320
The VT320 is an ANSI standard computer terminal introduced by Digital Equipment Corporation (DEC) in 1987. The VT320 is the text-only version, while the VT330 adds monochrome ReGIS, Sixel and Tektronix 4010 graphics, and the VT340 adds color. The 300 series replaced the earlier VT200 series, as a lower-cost system better able to compete with a number of VT220 clones that had entered the market. Foremost among these was the Wyse WY-60, introduced in 1986 with a form factor and feature set similar to the VT220, but including 4010 graphics and selling for only $699, compared to $795 for the base-model VT220 lacking graphics. The VT320 was introduced at $495, something of a surprise,David Bright"DEC VT320 late, but low prices surprises" ''Computerworld'', 31 August 1987, p. 16. forcing Wyse to lower their prices to $599. The VT320 was replaced by the VT420 in 1990, but the VT340 remained in production until all of these models were replaced by the VT500 series in 1994. Descript ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VT520
The VT520 is an ANSI standard computer terminal introduced by Digital Equipment Corporation (DEC) in 1993 and 1994. The VT520 is a multi-session monochrome text-only terminal with a built-in 14" monitor. The VT510 was a single-session version, while the VT525 added color support and used a separate external monitor. The VT500s replaced all existing models of DEC's VT line, which at that time consisted of just the VT420 text and VT340 graphics terminals. It was introduced in an era when the market was being flooded by low-cost IBM PC clones which could perform the same functions using a terminal emulator while also running other software. DEC introduced the VT500s only a short time before selling off their entire terminal division in August 1995. This brought the VT series to a close, after a total of about six million terminals had been sold. The VT520 was available from Boundless Technologies until the company went defunct in 2003. Description By the mid-1990s the price of low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VT420 With German Keyboard
The VT-4 (), also known as the MBT-3000, is a Chinese third generation main battle tank built by Norinco for overseas export. Development During the development of Type 90-II/Al-Khalid (also known as MBT-2000) in the 1980s, the gearbox and engine were originally imported from Germany, but this plan was shelved due to the Western arms embargo. The powertrain instead was sourced from Ukraine, the same for most Chinese export vehicles at the time. China eventually developed domestic powertrains, which led to the creation of the MBT-3000 program for export customers. MBT-3000 was the successor of the Type-90II (MBT-2000) export tank. The MBT-3000 project later named as VT-4 began development in 2009 as a co-operation with First Inner Mongolia Machinery Factory and other companies. The MBT-3000 concept debuted at the 2012 Eurosatory. The tank was subsequently shown at the 2014 Norinco Armor Day and the 10th China International Aviation & Aerospace Exhibition as the VT-4. Design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VT220
The VT220 is a computer terminal introduced by Digital Equipment Corporation (DEC) in November 1983. The VT240 added monochrome ReGIS vector graphics support to the base model, while the VT241 did the same in color. The 200 series replaced the successful VT100 series, providing more functionality in a much smaller unit with a much smaller and lighter keyboard. Like the VT100, the VT200 series implemented a large subset of ANSI X.364. Among its major upgrades was a number of international character sets, as well as the ability to define new character sets. The VT200 series was extremely successful in the market. Released at $795, the VT220 offered features, packaging and price that no other serial terminal could compete with at the time. In 1986, DEC shipped 165,000 units, giving them a 42% market share, double that of the closest competitor, Wyse. Competitors adapted by introducing similar models at lower prices, leading DEC to do the same by releasing the less-expensive $545 V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cathode Ray Tube
A cathode-ray tube (CRT) is a vacuum tube containing one or more electron guns, which emit electron beams that are manipulated to display images on a phosphorescent screen. The images may represent electrical waveforms ( oscilloscope), pictures (television set, computer monitor), radar targets, or other phenomena. A CRT on a television set is commonly called a picture tube. CRTs have also been used as memory devices, in which case the screen is not intended to be visible to an observer. The term ''cathode ray'' was used to describe electron beams when they were first discovered, before it was understood that what was emitted from the cathode was a beam of electrons. In CRT television sets and computer monitors, the entire front area of the tube is scanned repeatedly and systematically in a fixed pattern called a raster. In color devices, an image is produced by controlling the intensity of each of three electron beams, one for each additive primary color (red, green, and bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VT52
The VT50 was a CRT-based computer terminal introduced by Digital Equipment Corporation (DEC) in July 1974. It provided a display with 12 rows and 80 columns of upper-case text, and used an expanded set of control characters and forward-only scrolling based on the earlier VT05. DEC documentation of the era refers to the terminals as the DECscope, a name that was otherwise almost never seen. The VT50 was sold only for a short period before it was replaced by the VT52 in September 1975. The VT52 provided a screen of 24 rows and 80 columns of text and supported all 95 ASCII characters as well as 32 graphics characters, bi-directional scrolling, and an expanded control character system. DEC produced a series of upgraded VT52's with additional hardware for various uses. The VT52 family was followed by the much more sophisticated VT100 in 1978. Description The VT50 supported asynchronous communication at baud rates up to 9600 bits per second and did not require any fill characters. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VT100
The VT100 is a video terminal, introduced in August 1978 by Digital Equipment Corporation (DEC). It was one of the first terminals to support ANSI escape codes for cursor control and other tasks, and added a number of extended codes for special features like controlling the status lights on the keyboard. This led to rapid uptake of the ANSI standard, which became the de facto standard for hardware video terminals and later terminal emulators. The VT100 series, especially the VT102, was extremely successful in the market, and made DEC the leading terminal vendor at the time. The VT100 series was replaced by the VT200 series starting in 1983, which proved equally successful. Ultimately, over six million terminals in the VT series were sold, based largely on the success of the VT100. Description DEC's first video terminal was the VT05 (1970), succeeded by the VT50 (1974), and soon upgraded to the VT52 (1975). The VT52 featured a text display with 80 columns and 24 rows, bidirection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Server
A terminal server connects devices with a serial port to a local area network (LAN). Products marketed as terminal servers can be very simple devices that do not offer any security functionality, such as data encryption and user authentication. The primary application scenario is to enable serial devices to access network server applications, or vice versa, where security of the data on the LAN is not generally an issue. There are also many terminal servers on the market that have highly advanced security functionality to ensure that only qualified personnel can access various servers and that any data that is transmitted across the LAN, or over the Internet, is encrypted. Usually, companies that need a terminal server with these advanced functions want to remotely control, monitor, diagnose and troubleshoot equipment over a telecommunications network. A console server (also referred to as console access server, console management server, serial concentrator, or serial console ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modified Modular Jack
The Modified Modular Jack (MMJ) is a small form-factor serial port connector developed by Digital Equipment Corporation (DEC). It uses a modified version of the 6P6C modular connector with the latch displaced off-center so standard modular connectors found on Ethernet cables or phone jacks cannot accidentally be plugged in. MMJ connections are used on Digital minicomputers, such as the PDP-11, VAX and Alpha systems, and to connect terminals, printers, and serial console servers.Andrew Oliviero, Bill Woodward ''Cabling: The Complete Guide to Copper and Fiber-Optic Networking'', John Wiley & Sons, 2009, ISBN 470550058, page 295 The MMJ connector has six conductors, using a superset of the RS-423 serial communication standard. The six pins are Tx and Rx for the data transmission, their return paths, and DSR and DTR for handshaking. The transmit and receive signals are differential, i.e. each signal is the voltage difference between the line and its associated ground, as opposed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ANSI Escape Code
ANSI escape sequences are a standard for in-band signaling to control cursor location, color, font styling, and other options on video text terminals and terminal emulators. Certain sequences of bytes, most starting with an ASCII escape character and a bracket character, are embedded into text. The terminal interprets these sequences as commands, rather than text to display verbatim. ANSI sequences were introduced in the 1970s to replace vendor-specific sequences and became widespread in the computer equipment market by the early 1980s. They are used in development, scientific, commercial text-based applications as well as bulletin board systems to offer standardized functionality. Although hardware text terminals have become increasingly rare in the 21st century, the relevance of the ANSI standard persists because a great majority of terminal emulators and command consoles interpret at least a portion of the ANSI standard. History Almost all manufacturers of video termin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
