System for displaying overlapping pages of information

摘要

Various size frames or pages of information elements stored in a computer system can be simultaneously displayed on a screen-based terminal. The computer processor identifies the screen position the user selects for each of the stored pages and the top-to-bottom order of the pages with respect to visibility in the event that pages overlap. The processor selects the pages in descending order, topmost page first. Information elements of selected pages are transferred to appropriate locations in a display memory only in the event that an auxiliary memory registers that an information element has not priorly been transferred to those locations. After all the pages are transferred, background data is written into each display memory location that the auxiliary memory registers as not having an information element transferred thereto. The display memory is scanned in a conventional manner to apply the display information therein to the viewing screen.