Color Display Window Control
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
In a color graphics display, a multiplane all-points-addressable (APA) buffer controls a palette from which an analog video signal is generated to drive a CRT. As disclosed, partitioning or windowing is provided by an additional APA plane which is used to control the source of displayed data. This source can be selected either from other APA planes or from digital or analog ports. Fig. 1 shows an APA graphics adapter providing video signals to a raster-scanned CRT display. If the APA buffer contains n planes, each picture element (pel) on the display can assume one of 2n colors, as determined by a mapping contained in a palette store. The palette store output is passed through a digital-to-analog converter (DAC) to provide analog video for a display monitor.