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:
Apr. 11, 1989
Filed:
Dec. 24, 1986
Applicant:
Inventors:
William C Wickes, Corvallis, OR (US);
Laurence W Grodd, Portland, OR (US);
Assignee:
Hewlett-Packard Company, Palo Alto, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ; G06F / ;
U.S. Cl.
CPC ...
364900 ; 364706 ; 36471005 ;
Abstract
A method and apparatus for recovery of a computation stack in a calculator is presented in accordance with a preferred embodiment of the present invention. In a calculator employing a stack for the storage of data to be utilized in a calculation, provision is made to store the contents of the stack before a calculation is performed. If, after the calculation is performed a user desires to 'undo' the calculation, he may strike an 'undo' key. The original state of the stack is then restored.