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:
Nov. 08, 1994
Filed:
Jan. 24, 1991
Applicant:
Inventor:
Koji Takeda, Suwa, JP;
Assignee:
Seiko Epson Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G06F / ; G06F / ; G06F / ; G09G / ;
U.S. Cl.
CPC ...
395425 ; 395164 ; 345185 ; 345201 ; 364D / ;
Abstract
A system for improving access time to video display data uses a shadow memory having fewer storage locations than a display memory. The shadow memory and the display memory share a set of addresses such that data written to the display memory, at an address shared by the shadow memory, is identically written to the shadow memory. Read requests directed to the display memory result in: (a) data returned from the shadow memory when access to a shared address is requested, and (b) data returned from the display memory when access to a non-shared address is requested.