Historical Document · 1977

US Patent 4,055,757: Calculator Apparatus with Annuity Switch for Performing Begin- and End-Period Annuity Calculations (Hewlett-Packard, HP-22)

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The BEGIN/END switch: filed 27 August 1976, granted 25 October 1977.

Author

L. W. Tillman, K. R. Henscheid, L. D. Smith

Year

1977

Type

Historical Document

Credit

US Patent and Trademark Office; via Google Patents.

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