The IBM 2250 Graphics Display Unit was a

vector graphics Vector graphics are a form of computer graphics in which visual images are created directly from geometric shapes defined on a Cartesian plane, such as points, lines, curves and polygons. The associated mechanisms may include vector displ ...

display system by

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

for the

System/360 The IBM System/360 (S/360) is a family of mainframe computer systems announced by IBM on April 7, 1964, and delivered between 1965 and 1978. System/360 was the first family of computers designed to cover both commercial and scientific applicati ...

; the Model IV attached to the

IBM 1130 The IBM 1130 Computing System, introduced in 1965, was IBM's least expensive computer at that time. A binary 16-bit machine, it was marketed to price-sensitive, computing-intensive technical markets, like education and engineering, succeeding th ...

Overview

The IBM 2250 Graphics Display Unit was announced with System/360 in 1964. A complete 2250 III system with controller cost around $280,000 in 1970, though up to 4 displays could share a single controller, reducing the cost per display by up to 40%. A display list of line segments (

vector Vector most often refers to: * Euclidean vector, a quantity with a magnitude and a direction * Disease vector, an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematics a ...

s) on a 1024 by 1024 grid was stored in

computer A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...

's memory or an optional buffer on the 2250 and repainted on the 2250's

CRT CRT or Crt most commonly refers to: * Cathode-ray tube, a display * Critical race theory, an academic framework of analysis CRT may also refer to: Law * Charitable remainder trust, United States * Civil Resolution Tribunal, Canada * Columbia ...

up to 40 times per second. The computer altered the display by changing the display list. Characters were built of line segments specified by display list

subroutines In computer programming, a function (also procedure, method, subroutine, routine, or subprogram) is a callable unit of software logic that has a well-defined interface and behavior and can be invoked multiple times. Callable units provide a p ...

. Thus any character set or

font In metal typesetting, a font is a particular size, weight and style of a ''typeface'', defined as the set of fonts that share an overall design. For instance, the typeface Bauer Bodoni (shown in the figure) includes fonts " Roman" (or "regul ...

could be displayed, although fonts were generally extremely simplified for performance reasons. An optional character-generator feature on all models provided predefined fonts of 63 characters to simplify display of alphanumeric information. The 2250 was housed in a desk with an alphanumeric (

QWERTY QWERTY ( ) is a keyboard layout for Latin-script alphabets. The name comes from the order of the first six Computer keyboard keys#Types, keys on the top letter row of the keyboard: . The QWERTY design is based on a layout included in the Sh ...

) keyboard and a separate programmed function keyboard which had keys, indicator lights and switches. A plastic overlay label could be placed over the function keyboard. Punches on the top edge of the overlay could be sensed by the computer so the keys, lights and switches could be reprogrammed simply by changing overlays. The 2250s CRT measured 21" diagonal, but the useful display area was 12 inch by 12 inch, or about 17 inches diagonal. A

light pen A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display. It allows the user to point to displayed objects or draw on the screen in a similar way to a to ...

was provided as a

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, serving the function of the modern

computer mouse A computer mouse (plural mice; also mouses) is a hand-held pointing device that detects Plane (mathematics), two-dimensional motion relative to a surface. This motion is typically translated into the motion of the Cursor (user interface)#Po ...

. An IBM 2285 Display Copier could be attached to the 2250 to provide 8½ by 11 inch hard copy of the display contents under operator control. An IBM 2280 Film Recorder or IBM 2282 Film Recorder/Scanner could be attached to a 2840 control unit providing for output or input/output to photographic negative. There were four models of 2250: * Model 1 – attached directly to a System/360 via a selector or multiplexor channel. * Model 2 – attached via a 2840-1 control unit. A 2840 could attach up to four 2250s and provided buffering and a

character generator A character generator, often abbreviated as CG, is a device or software that produces static or animated text (such as news crawls and credits rolls) for keying into a video stream. Modern character generators are computer-based, and they can ...

. * Model 3 – attached via a 2840-2 control unit. * Model 4 – attached to an

minicomputer via the storage access channel (SAC). The 1130 could run either as a standalone processor or as a front-end processor connected to a remote System/360.

Competitors

A number of plug compatible manufacturers sold competitors to the 2250, including

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Evans & Sutherland Evans & Sutherland is an American computer graphics firm founded in 1968 by David C. Evans (computer scientist), David Evans and Ivan Sutherland. Its current products are used in digital projection environments like planetariums. Its simulation b ...

, Information Displays Inc.,

Lundy Lundy is an English island in the Bristol Channel. It forms part of the district of Torridge in the county of Devon. About long and wide, Lundy has had a long and turbulent history, frequently changing hands between the British crown and ...

, Sanders, Spectragraphics, and Vector General.

Successors

In 1977 IBM introduced the 3250 Display System (manufactured by

Sanders Associates Sanders Associates, Inc. was a defense contractor in Nashua, New Hampshire, United States, from 1951 until it was sold in 1986. It is now part of BAE Systems Electronics & Integrated Solutions, a subsidiary of BAE Systems. It concentrated on de ...

) as an upgrade to the 2250.

References

External links

IBM System/360 Component Description IBM 2250 Display Unit Model 1
GA27-2701-3.
IBM System/360 Component Description IBM 2250 Display Unit Model 2 IBM 2840 Display Control Model 1
GA27-2702-0.
IBM System/360 Component Description IBM 2250 Display Unit Model 3 IBM 2840 Display Control Model 2
GA27-2721-0.
IBM 1130 Computing System Component Description IBM 2250 Display Unit Model 4
A27-2723-0.
IBM 1130/2250 Graphic Subroutine Package For Basic FORTRAN IV
C27-6934-0.
IBM 2250 Programming Information
{{DEFAULTSORT:Ibm 2250 2250 2250 Graphical terminals

Overview

Competitors

Successors

See also

References

External links