Computer graphics processing and selective visual display system – Display peripheral interface input device – Light pen for fluid matrix display panel
Patent
1993-03-02
1995-02-14
Chin, Tommy P.
Computer graphics processing and selective visual display system
Display peripheral interface input device
Light pen for fluid matrix display panel
345114, 345153, G09G 128
Patent
active
053899474
ABSTRACT:
A graphics subsystem, including a video digital-to-analog converter, is disclosed. A high speed oscillator generates a pixel clock signal at the frequency at which pixels are to be displayed. Included in the video DAC is a frequency divider which presents an output clock signal having a period which is a multiple of the pixel clock signal, the multiple corresponding to the level of multiplexing of pixel data to be provided by the video DAC; this multiple can equal unity. The video controller in the system receives the output clock signal, and generates clock signals to control the serial port of the frame memory, and also to control the latching of the first stage in the video DAC. The first stage latch in the video DAC latches in the multiple pixel data from the frame memory, and the multiplexer in the video DAC presents the data to the color palette RAM, or around the color palette RAM in true-color non-multiplexed mode, according to the pixel clock signal. Highlighted pixels in a cursor are displayed by inverting the output of the color palette RAM at cursor locations, for example by way of an exclusive-OR function of the color palette RAM output and a bit corresponding to the comparison of the display location and the desired cursor location. Inversion of the output of the color palette RAM results in higher contrast pixels within the cursor.
REFERENCES:
patent: Re31200 (1983-04-01), Sukonick et al.
patent: 4467322 (1984-08-01), Bell et al.
patent: 4626835 (1986-12-01), Nienaber et al.
patent: 4668947 (1987-05-01), Clarke, Jr. et al.
patent: 4808989 (1989-02-01), Tabata et al.
patent: 4835526 (1989-05-01), Ishii et al.
patent: 5140312 (1992-08-01), Ishii
patent: 5146211 (1992-09-01), Adams et al.
patent: 5185597 (1993-02-01), Pappas et al.
Hamacher et al., Computer Organization (McGraw-Hill, 1978), pp. 432 and 434.
Product Selection Guide (Brooktree Corporation, 1991), pp. 11, 13, 14, 16.
Albers Thomas M.
Preston Stephen B.
Wood Paul B.
Au A.
Chin Tommy P.
Compaq Computer Corporation
LandOfFree
Circuitry and method for high visibility cursor generation in a does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Circuitry and method for high visibility cursor generation in a , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Circuitry and method for high visibility cursor generation in a will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-290580