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.

Date of Patent:
May. 29, 1979

Filed:

Aug. 11, 1976
Applicant:
Inventors:

David J McElroy, Houston, TX (US);

Graham S Tubbs, Houston, TX (US);

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
364900 ; 364736 ;
Abstract

A digital processor which may be used in a calculator is provided by an MOS/LSI semiconductive chip which contains a bit-parallel arithmetic unit for operating on data stored in a random access memory. Selector units determine which of several sources produce the inputs to the arithmetic unit. The random access memory has X and Y, or page and word addressing. Part of the random access memory provides direct access for readout. Numerical data at the Y address in the direct access memory is always available at the selector units for input to the arithmetic unit, at the same time that data at the same Y address but another X address is read out to be also an input to the arithmetic unit. The direct access part of the memory is addressed for write in by the same addressing means as the remainder of the memory. This arrangement reduces the number of machine cycles needed for arithmetic operations, and so provides faster calculations.


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