Personal computer apparatus for block transfer of bit-mapped image data

A personal computer system to provide video output signals to a raster display, wherein an image consisting of a plurality of pixels is assembled on a screen of the raster display by an electron beam scanning the screen, wherein the visual characteristics of a pixel being scanned by the electron beam are determined by the video output signals provided by the personal computer system when the pixel is being scanned, and wherein the image includes a region bounded by two vertical lines, and wherein the personal computer system comprises:

• central processor means for executing program instructions;
• memory means including a plurality of addresses for storing bit-mapped image data, wherein the visual characteristics of a pixel are defined by bit-mapped image data stored in at least one address corresponding to the pixel;
• data bus means coupled to the processor means and the memory means for transferring data;
• address bus means coupled to the processor means and the memory means for transferring an address to the memory means;
• pointer means, coupled to the address bus means, for selecting a source address in the memory means as a source of unprocessed bit-mapped image data to be transferred on the data bus means, and for selecting a destination address in the memory means as a destination of processed bit-mapped image data to be transferred on the data bus means;
• blitter means, coupled to the data bus means, for transferring a block of bit-mapped image data between the blitter means and the memory means, and for processing the block of bit-mapped image data, wherein the blitter means includes:
• means for receiving from the data bus means unprocessed bit-mapped image data stored in the memory means at the source address;
• logic means, for executing a logical operation on unprocessed bit-mapped image data to generate processes bit-mapped image data, wherein the logic means includes fill logic means, for detecting bit-mapped image data corresponding to each of the two vertical lines during processing of bit-mapped image data corresponding to one horizontal line of the image, and for changing bit-mapped image data corresponding to the region of the one horizontal line bounded by the two vertical lines in order to fill the bounded region;
• and
• means for providing the processed bit-mapped image data to the data bus means for storage in the memory means at the destination address;
• and
• image display means, for receiving bit-mapped image data stored in at least one address corresponding to a pixel, and for generating the video output signals.