Superimposing Two Drawings on Display Screen
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
A program is disclosed for an IBM Personal Computer (PC) with a color graphics display which allows two or more drawings in different color to be superimposed or overlaid for alternately displaying data for each from a different buffer at half screen refresh rate. An application is to display one side of a printed circuit in blue, the other in red so that coincident conductors appear to be magenta. In an application for an IBM PC Color Graphics Adapter (CGA) with four display buffers available, where it is desirable to edit two or more files effectively simultaneously, and where the files are related to one another in such a way that they still make sense when overlaid, the following technique has proved useful.