Superimposed Logic Circuit
Original Publication Date: 1989-Feb-01
Included in the Prior Art Database: 2005-Jan-27
This articles describes a superimpose logic circuit based on an existing color palette circuit. The circuit is applicable to color bit map display systems. The circuit defines which color or colors from a color bit map memory should be superimposed. The character or graphics image written on the color bit map memory is automatically superimposed to another bit map data by using this circuit. The figure shows a typical application of the superimposed circuit. The application system is composed of two color bit map memories 10, 12 (one is for graphics and the other is for image, as an example), two color palettes 14, 16 and the superimposed circuit 18. The superimposed circuit 18 consists of four one-bit superimposed registers located in the color palette 14 and the superimposed control circuit.