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The VT220 was an ANSI standard computer terminal introduced by Digital Equipment Corporation (DEC) in 1983.〔(【引用サイトリンク】title=VT220 Programmer Reference Manual )〕 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. Among its major upgrades was a number of international characters, 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 touch. 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 price points, leading DEC to do the same by releasing the less-expensive $545 VT300 series in 1987. By that time, DEC had shipped over one million VT220s.〔David Bright, ("DEC VT320 late, but low prices surprises" ), ''Computerworld'', 31 August 1987, p. 16.〕 ==Hardware== The VT220 improved on the earlier VT100 series of terminals with a redesigned keyboard, much smaller physical packaging, and a much faster microprocessor. The VT220 was available with CRTs that used white, green, or amber phosphors. The VT100s, like the VT50s before them, had been packaged in relatively large cases that provided room for expansion systems. The VT200s abandoned this concept, and wrapped the much smaller 1980s-era electronics tightly around the CRT. The result was a truncated pyramidal case with the apex at the back, only slightly larger than the CRT. This made it much easier to fit the terminal on a desk. An adjustable stand allowed the angle of the CRT to be adjusted up and down. Because it was lower than head height, the result was an especially ergonomic terminal. The LK201 keyboard supplied with the VT220 was one of the first full-length, low-profile keyboards available; it was developed at DEC's Roxbury, Massachusetts facility. It was much smaller and lighter than the VT100s version, and connected to the terminal using a lighter and more flexible coiled cable and a telephone jack connector. The VT200s were the last DEC terminals to provide a 20mA current loop serial interface, an older standard originally developed for the telegraph system. A standard 25-pin D-connector was also provided for RS-232. Only one of the two ports could be in use at a given time. Later DEC terminals would replace both of these with their proprietary Modified Modular Jack (MMJ) connectors. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「VT220」の詳細全文を読む スポンサード リンク
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