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From: jcohen@lehi3b15.csee.Lehigh.EDU (Josh Cohen [890918])
Newsgroups: comp.sys.handhelds
Subject: Re: HP48 w/o batteries
Keywords: HP48
Message-ID: <1522@lehi3b15.csee.Lehigh.EDU>
Date: 22 Apr 91 01:56:18 GMT
References: <1991Apr18.052937.7060@ux1.cso.uiuc.edu>
Reply-To: jcohen@lehi3b15.csee.Lehigh.EDU (Josh Cohen [890918])
Organization: CSEE Dept. Lehigh University, Bethlehem, PA
Lines: 4

I am not exactly sure but a common way to do that is with a capacitor..
a slow decay, hi energy type.  you can keep the calculator off for the
duration of the decay period of the capacitor.
jcohen@scarecrow.csee.lehigh.edu