04821228 is referenced by 13 patents and cites 10 patents.

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.

Title
Method and apparatus for computation stack recovery in a calculator
Application Number
6/946543
Publication Number
4821228
Application Date
December 24, 1986
Publication Date
April 11, 1989
Inventor
Laurence W Grodd
Portland
OR, US
William C Wickes
Corvallis
OR, US
Assignee
Hewlett Packard Company
CA, US
IPC
G06F 11/00
G06F 15/06
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