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:
Sep. 02, 1986
Filed:
Aug. 12, 1983
David A Kummer, Boca Raton, FL (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A microcomputer includes a main memory system which is accessed, substantially independantly, by the CPU and a subsystem, for example a video display subsystem. The memory system comprises a base memory and an optical add on expansion memory. When only the base memory is installed, consecutive locations have consecutively numbered addresses, and both the CPU and subsystem access individual locations. When both memories are installed, one has even numbered addresses and the other odd numbered addresses. With both memories installed, the CPU still accesses individual locations, but the subsystem addresses even addresses to obtain, for each access, data from the even address and the next higher odd address, thereby accessing a location in both memories. Thus the memory bandwidth for the subsystem is effectively doubled when the expansion memory is installed.