Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!coplex!disk!corpane!herman
From: herman@corpane.uucp (Harry Herman)
Newsgroups: comp.sys.handhelds
Subject: Re: HP48 w/o batteries
Message-ID: <1991Apr19.095021.10150@corpane.uucp>
Date: 19 Apr 91 09:50:21 GMT
References: <1991Apr18.052937.7060@ux1.cso.uiuc.edu> <4241@rwthinf.UUCP>
Organization: Corpane Industries Inc.
Lines: 28

In <4241@rwthinf.UUCP> berg@marvin.e17.physik.tu-muenchen.de (Stephen R. van den Berg) writes:

>Charlie Reiman writes:
>>Does anyone know how long the HP48's memory remains intact with the batteries
>>out?

>Talking about removing the batteries...  What happens to any plugged in
>memory expansion cards?  Do they get drained, or do they simply shut
>themselves off?  (I guess the latter, but can anybody confirm this?)
>--
>Sincerely,                 berg@marvin.e17.physik.tu-muenchen.de
>           Stephen R. van den Berg.
>"I code it in 5 min, optimize it in 90 min, because it's so well optimized:
>it runs in only 5 min.  Actually, most of the time I optimize programs."

I believe the calculator can maintain its own memory for about 2 minutes
with the batteries removed.  This is so you have time to put new batteries
in.

As concerns the RAM cards, each card has its own built in battery that is
supposed to last 5 years.  When the calculator is shut off, or the cards
are removed from the calculator, there is a chip on the cards that isolate
them from the HP48 until such time as they detect 4.1V or more on the
power supply pins again.


				Harry Herman
				herman@ukma!corpane