Abstract: A method and apparatus for generating both a true color and fast pseudo color video signals includes the combination of first and second commercially available RAMDACs. Parallel video data representing the red, blue, and green color components of one or more pixels is provided on a video bus to the inputs of the first and second RAMDACs. A first data portion of the parallel video data is presented to the input of the first RAMDAC, which can represent either a single pixel in the fast pseudo color mode or the most significant pixel data. A second data portion of the parallel video data is presented to the input of the second RAMDAC, which can represent either another single pixel in the fast pseudo color mode or the least significant pixel data. The outputs of the two RAMDACs are combined to provide true color video signals in a first RAM programming mode, and the respective outputs of the two RAMDACs are multiplexed to provide fast pseudo color video signals in a second RAM programing mode.

Abstract: A raster graphic refresh memory architecture offering increased access speed. The memory takes advantage of the "page mode" of operation of dynamic random-access memory integrated circuit devices which require two separate device addresses for random access to a storage location therein but permit in "page mode" a first address corresponding to a set of storage locations to be maintained while changing the second address for more rapid access. The memory is organized so that a portion of the second device address is allocated to the least significant bits of one dimension of the display address and another portion of the second device is allocated to the least significant bits of another dimension of the display address, thereby forming a two-dimensional cell of storage locations on a single page corresponding to a region on the display.