The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 07, 1989
Filed:
Sep. 21, 1987
Paul Schreiber, Fort Worth, TX (US);
Tandy Corporation, Fort Worth, TX (US);
Abstract
A high resolution video graphics system for use with a processor and characterized by improved memory expandability particularly in connection with color display. The high resolution video graphics system includes a video memory which is preferably comprised of a plurality of video memory planes and video counter means for providing display timing. There are basically four buses that are used with the system including a control bus, a read bus, a write bus, and an address bus. A multiplexer means is provided for receiving either video counter addresses or direct addresses from the processor. There is associated with the video memory means for converting to serial output data which the preferred embodiment includes a series of shift registers corresponding to the number of separate memory planes employed. In the preferred embodiment the system has three memory planes, each of 16K by 16 capacity. The shift register output is coupled to a high speed static palette RAM with the shift register outputs being the addresses thereto. The data outputs of the palette RAM couple to guns on a color monitor or to the back plane in connection with black and white graphics.