A graphics and video controller 105 is provided which includes a dual
aperture interface 206 for receiving words of graphics and video pixel
data, each word of such data associated with an address directing that
word to be processed as either graphics or video data. Circuitry 200,
201, 202, 207, 208 is provided for writing a word of the pixel data
received from the interface 206 to a one of the on- and off-screen memory
areas corresponding to the address associated with the received word.
Circuitry 201, 202 is provided for selectively retrieving graphics and
video data from the on-screen and off-screen memory areas. A first
pipeline 205 is provided for processing data received from the on-screen
area of frame buffer 107 while a second pipeline 204 is provided for
processing data retrieved from the off-screen area of the frame buffer.