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:
Jun. 19, 1984
Filed:
Feb. 20, 1981
Jack M Walden, Loveland, CO (US);
William D Eads, Loveland, CO (US);
Ray J Cozzens, Loveland, CO (US);
John L Bidwell, Loveland, CO (US);
Robert A Jewett, Loveland, CO (US);
Martin S Wilson, Loveland, CO (US);
Daniel J Griffin, Loveland, CO (US);
Robert E Kuseski, Loveland, CO (US);
Louis T Schulte, Loveland, CO (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A programmable calculator employs modular read-write and read-only memories separately expandable to provide additional program and data storage functions within the calculator oriented toward the environment of the user and two sixteen bit LSI NMOS central processing units. One of the central processing units (LPU) is employed to perform language syntaxing, arithmetic, and general supervision of program execution. The second central processing unit (PPU) is employed for managing input/output operations. Communication between the two central processing units is accomplished by an arrangement through which the two central processing units share a common portion of memory. The calculator also includes a keyboard having a full complement of alphanumeric keys for entering programs and data into the calculator and for otherwise allowing the user to control operation of the calculator. The keyboard further includes a plurality of user-definable keys, some of which are pre-defined to have certain definitions at the time operating power is applied to the calculator.