The IBM 2250 Graphics Display Unit was a

vector graphics Vector graphics is 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 display ...

display system by IBM for the System/360; 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 *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

s) on a 1024 by 1024 grid was stored in

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

's memory or an optional buffer on the 2250 and repainted on the 2250's CRT 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 or subroutine is a sequence of program instructions that performs a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed. Functions may ...

. Thus any character set or

font In metal typesetting, a font is a particular size, weight and style of a typeface. Each font is a matched set of type, with a piece (a "sort") for each glyph. A typeface consists of a range of such fonts that shared an overall design. In mod ...

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 left letter row of the keyboard ( ). The QWERTY design is based on a layout created f ...

) 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. 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 tou ...

was provided as a

pointing device A pointing device is a human interface device that allows a user to input spatial (i.e., continuous and multi-dimensional) data to a computer. CAD systems and graphical user interfaces (GUI) allow the user to control and provide data to ...

, serving the function of the modern

computer mouse A computer mouse (plural mice, sometimes mouses) is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the motion of a pointer on a display, which allows a smooth c ...

. 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. * 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

Adage An adage (; Latin: adagium) is a memorable and usually philosophical aphorism that communicates an important truth derived from experience, custom, or both, and that many people consider true and credible because of its longeval tradition, i.e. ...

Evans & Sutherland Evans & Sutherland is a pioneering American computer firm in the computer graphics field. Its current products are used in digital projection environments like planetariums. Its simulation business, which it sold to Rockwell Collins, sold products ...

, Information Displays Inc.,

Lundy Lundy is an English island in the Bristol Channel. It was a micronation from 1925–1969. 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 chang ...

, Sanders, Spectragraphics, and

Vector General Vector General (VG) was a series of graphics terminals and the name of the Californian company that produced them. They were first introduced in 1969 and were used in computer labs until the early 1980s. The terminals were based on a common platfo ...

.Jon Peddie, ''The History of Visual Magic in Computers: How Beautiful Images are Made in CAD, 3D, VR, and AR'', 2013,
p. 314-315
/ref>

Successors

In 1977 IBM introduced the 3250 Display System (manufactured by Sanders Associates
) 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