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(11) | EP 0 363 204 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Generation of raster scan video signals for an enhanced resolution monitor |
| (57) The converter circuit (3) provides for the generation of a raster scan video signal
to an enhanced resolution monitor in either a first, high resolution mode or a second,
low resolution mode, the circuit (3) comprises: a video timing generator (7) connected
to receive timing signals from the video adaptor (1); a multiplexer (11) connected
to receive a video output signal from the video adaptor (1); a video line buffer (6)
connected to receive the video output signal from the video adaptor (1) and connected
to the multiplexer (11); and output means (9) connected to receive a video output
signal from the multiplexer (11) for providing a video output signal to an enhanced
resolution monitor, and converter circuit (3) being selectively operable in a first
mode in which video information from the video adapter (1) is converted by the multiplexer
(11) for a high resolution, monochrome display and then provided to the output means
(9), and a second mode in which video information for a low resolution, multi-colour
display is received by the multiplexer (11) from the video adapter (1) via the buffer
(6) such that each pixel of information is read out twice from the buffer (6) and
each line of information is read out twice to provide the output means (9) with a
video output signal of a low resolution display to be produced on an enhanced resolution
monitor. |