From otti@megatel.de (Thomas Otten)
Newsgroups: comp.sys.hp48
Subject: Expanding the 48G - there's more to do
Date: Mon, 6 Jun 94 07:08:25 GMT

Hi,
since some people sent me very nice email in response to my posting about  
expanding the memory of the 48G I decided to try a way to get even more  
memory. Since this was only half successful I would like to hear your  
opinions about the problems I have before posting that way.

I added one IC to the G (took me 50 cents, this seems to get expensive ;-)  
) and reenabled the internal 32K. The 128K are now connected to my G like  
a memory card to an GX. I turned on my G, merged the RAM and got (nearly)  
160K free memory. WOW. Then I tried to fill that memory (large matrix  
object) ... BOOOOM. "TRY TO RECOVER MEMORY ?". After that my G thought he  
has 256K, but I couldn't agree with that. I opened it again and searched  
for a mistake in my wiring but didn't find one (this doesn't mean there is  
none but keep on reading). So I started it again without merging the  
memory and did some backups to port one (this is my 128K chip now) and  
filled it step by step that way until it was nearly full (it's nice to  
back up your 32K more than once :-) ). There were no problems. I cleared  
the memory (ON-A-F - "RECOVER?" NO!) and did a restore from port 1 (a "RAM  
card" is not cleared that way) .. no problems. Everything is back again.

This makes me thing the way I connected the RAM can't be very wrong. If  
anyone who knows more about the internals of the HP could please think  
about this:

1) My G has ROM version K (the very first one :-( ). The FAQ says this  
release never was in an GX and even the L version has some bugs about port  
mamangement. What are that bugs and may that be the reason for my  
problems?

2) The G(X) was never designed to have 32K base RAM and 128K port memory  
being merged. Do you think this is the reason? Maybe I should buy a second  
128K chip and extend both to 128K? (I don't need that much memory but that  
shouldn't stop me...)

Greetings, Thomas


Start "why is this in comp.sys.hp48?"...
If someone in Dallas reads this: if you have time and fun doing so, could  
you please mail me what I shouldn't miss in Dallas and where to shop  
(electronics, computer and such stuff) in your city? I'll spend one week  
there in July.
End "why is this in comp.sys.hp48?"...


Thomas Otten      otti@megatel.de (NeXTmail welcome)      
                  megatel GmbH * Wiener Str. 3 * 28359 Bremen * Germany
                  Voice: ++49-421-22095-0     FAX:++49-421-22095-16                                      

From mauriceo@stack.urc.tue.nl (Maurice Oude Tijdhof)
Newsgroups: comp.sys.hp48
Subject: Expanding RAM in a 48SX
Date: 6 Jun 1994 11:44:42 GMT

I heard from some people that the 32K chip in the HP48SX can not be replaced
by a 128K chip. Who of you knows if this is possible or not. Is there
someone who has already done it.
Another way is to place the chip as a ram card memory and merge it with the
32Kchip. I've read that this cannot be done at the 48G. (Can it be done on
the 48SX ??)

These are a lot of questions, but has anyone answers ???

--
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/           Maurice Oude Tijdhof              /
/                                             /
/       e-mail: mauriceo@stack.urc.tue.nl     /
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