- Vector monitor
Outline
Graphical displays for early computers used vector monitors, a type of CRT similar to the
oscilloscope but typically using magnetic, rather than electrostatic, deflection.Fact|date=April 2008 Here, the beam traces straight lines between arbitrary points, repeatedly refreshing the display as quickly as possible.Vector monitors were used by some late-1970s to mid-1980s arcade games such as "Asteroids". [cite book | title = Supercade: A Visual History of the Videogame Age, 1971-1984 | author = Van Burnham | publisher = MIT Press | year = 2001 | isbn = 0262524201]
Atari used the term "Quadrascan" to describe the technology when used in their games.Vector displays for computers did not noticeably suffer from the display artifacts of
Aliasing andpixelization , but were limited in that they could display only a shape's outline (advanced vector systems could provide a limited amount of shading), and only a limited amount of crudely-drawn text (the number of shapes and/or textual characters drawn was severely limited, because the speed of refresh was roughly inversely proportional to how many vectors needed to be drawn).Color displays
Some vector monitors are capable of displaying multiple colors, using either a typical tri-color CRT, or two phosphor layers (so-called "penetration color").Fact|date=April 2008 In these dual-layer tubes, by controlling the strength of the electron beam, electrons could be made to reach (and illuminate) either or both phosphor layers, typically producing a choice of green, orange, or red. Atari used the term "Color Quadrascan" to describe this colour version when used in their games.
Other graphical displays used '
storage tube s', including Direct View Bistable Storage Tubes (DVBSTs). These CRTs inherently stored the image, and did not require periodic refreshing.References
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