The IBM 740 CRT Recorder was announced in 1954 and used with the
IBM 701,
IBM 704
The IBM 704 is the model name of a large digital computer, digital mainframe computer introduced by IBM in 1954. Designed by John Backus and Gene Amdahl, it was the first mass-produced computer with hardware for floating-point arithmetic. The I ...
, and
IBM 709 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 to draw
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 ...
images, point by point, on
35 mm photographic film
Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the ...
(i.e.
microfilm). The 740
film recorder contained
digital-to-analog converters and a 7-inch, high precision,
electrostatic CRT. The raster size was 1,024 by 1,024, but only 256 resolved spots could be displayed on a vertical or horizontal line. Points could be displayed in one of two intensities, and a line could be drawn from a point, vertically or horizontally, to the edge of the display to form an axis.
Each point to be displayed was stored in a single 36-bit word, with 10 bits each for the X and Y coordinates, and 3 control bits, one to set either high or low intensity and two to indicate that an X or Y axis is to be drawn starting from the given point. If both the X and Y axis bits were set, a 45-degree line was drawn.
The 740's CRT used a short persistence ''P11''
phosphor
A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or ...
. The film used was 35 mm and was stored in a magazine that could hold up to 100 feet.
ASA 200
speed film was recommended. The film could be advanced under computer control.
The IBM 780 CRT Display was a monitor that could be attached to the 740 and mirror to an operator what was being drawn on 740's CRT. The 780 had a 21-inch CRT with a longer persistence (2 second, nominal) ''P7'' phosphor.
See also
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IBM 2250
*
Phosphor#Standard phosphor types
References
*
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 ...
709 Data Processing System, Form A22-6501-0, 1958, p. 106ff.
*
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External links
IBM display devices, 740
Display 740
History of human–computer interaction
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