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HP Forum Archive 14

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Memory expansion on GX
Message #1 Posted by Ric Manohar on 26 Sept 2004, 6:20 p.m.

This might sound dumb, but is memory cards for the GX available that doesn't use a backup battery.

      
Re: Memory expansion on GX
Message #2 Posted by Cyril RABIH on 27 Sept 2004, 8:42 a.m.,
in response to message #1 by Ric Manohar

I don't think so but there's an easy way to test it. Just remove the batteries from your card and I think that the card will use the calculator's batteries to keep data. Disable message errors when you start the calculator. The problem is that the 48 series canno't use flash memory but RAM memory instead. RAM needs to be permanently powered and if you doesn't have enough power, the card will use the unit's power. I hope it will help you. Best regards, Cyril

      
Re: Memory expansion on GX
Message #3 Posted by James M. Prange on 27 Sept 2004, 8:43 a.m.,
in response to message #1 by Ric Manohar

Not that I know of, but the newer SMI RAM cards have a rechargeable "10-year" battery. It's recharged from the AAA cells, provided that they're strong enough. My impression is that the 10-year battery is non-replaceable, but I may be mistaken about that. How well it works out, for example, what happens if the 10-year battery is allowed to go completely dead, I don't know. See:

How to Resolve the HP 48 "low battery p(2)" Message
at http://www.smi.com/Support/topics.htm.

I don't expect that flash memory would work with the 48 design without extensive modification.

Regards,
James

      
Re: Memory expansion on GX
Message #4 Posted by Emmanuel, France on 27 Sept 2004, 12:17 p.m.,
in response to message #1 by Ric Manohar

I saw somewhere that there was Flash Cards for HP-48...

            
Re: Memory expansion on GX
Message #5 Posted by Raymond Del Tondo on 27 Sept 2004, 3:23 p.m.,
in response to message #4 by Emmanuel, France

I used EPROM cards for my SX and GX:-)

Raymond

                  
Re: Memory expansion on GX
Message #6 Posted by James M. Prange on 27 Sept 2004, 5:51 p.m.,
in response to message #5 by Raymond Del Tondo

Quote:
I used EPROM cards for my SX and GX:-)
Ah, good point!

But I assumed that Ric meant "RAM" cards; that is, memory that could be both read and written in the calculator.

Regards,
James

                  
Re: Memory expansion on GX
Message #7 Posted by Karl on 27 Sept 2004, 6:07 p.m.,
in response to message #5 by Raymond Del Tondo

How did you that Raymond????

                        
Re: Memory expansion on GX
Message #8 Posted by Raymond Del Tondo on 27 Sept 2004, 7:04 p.m.,
in response to message #7 by Karl

Long time ago EPSON sold suitable 8bit EPROM cards to OEMs.
If you are lucky having bought a W&W software card for the HP-48,
like the Assembler ROM, or the Surveying Pac,
you're likely to have an EPROM card:-)

At W&W we used an EPROM burner called SprintPlus,
at home I used a small ISA slot unit called PB-10 from Needhams's Electronics.
Both have optional slots/sockets for those EPSON cards.

There were several ways to produce the image needed for the EPROM.
The easiest way was to read the contents of an HP-48 RAM card into the burner buffer,
then burning the buffer contents.

Regards,

Raymond

                              
Re: Memory expansion on GX
Message #9 Posted by Karl on 28 Sept 2004, 3:43 a.m.,
in response to message #8 by Raymond Del Tondo

Many thanks Raymond, now I understand.


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