Display generator circuitry for personal computer system

Abstract From the Canadian patent

A method of generating a display for a video game and a home computer system having a television-type display device, a microprocessor, a general RAM memory an address bus, a data bus, and utilizing direct memory access, comprises the steps of storing display information in the memory in bit map format; separating display information in the bit map storage into contiguous blocks representative of sprite object data and of bitplanes where sprite object data defines a complete movable display object, and bitplane data defines a playfield whereof a playfield is formed of a composite of a plurality of bitplanes; compositing a playfield by sequentially adding data from a plurality of bitplanes …