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HP Forum Archive 13

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48 series memory cards
Message #1 Posted by unspellable on 21 Aug 2003, 1:09 p.m.

In the 48SX and 48GX, if a RAM card is merged with user memory, it presumably will stay in place and not be taken out and put back in like a card used for backup, storage, or moving programs from one calculator to another.

In this case, is there really any purpose in having the backup battery in the card? Other than it keeps the low battery warning shut off?

      
Re: 48 series memory cards
Message #2 Posted by Ron Ross on 21 Aug 2003, 1:19 p.m.,
in response to message #1 by unspellable

You would probalby lose all memory on a battery change also (the capacitor barely keeps the original memory intact, much less extra).

Just my thoughts, not proven one way or the other.

            
Re: 48 series memory cards
Message #3 Posted by unspellable on 21 Aug 2003, 6:09 p.m.,
in response to message #2 by Ron Ross

I don't know about the 48 series, but I have an HP 28S here that was intermittent. It had been dropped once too often. Thinking there might be a crack somewhere I took it to our failure lab and had it X-rayed. All during this examination it had no batteries in it. Went twenty minutes or so. Upon replacing the batteries there was the entire memory intact!

Just as an experiment I might try to see how long a 48 will hold up without batteries.

I suppose one should have a cell in the RAM card just to avoid the nuisance of a low battery warning if nothing else.

      
Re: 48 series memory cards
Message #4 Posted by R Lion on 21 Aug 2003, 4:18 p.m.,
in response to message #1 by unspellable

If I'm not wrong, the card NEEDS its battery for keeping the stuff stored when the calc is off. The three main AAA batteries only "feed" the card when the calc is on.

Raul


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