Re: HP25-C Message #2 Posted by David Smith on 9 Feb 2005, 4:01 p.m., in response to message #1 by Louis
The only source of the chips is another machine. You can find compatible chips in the HP25C or HP29C. The 25C had two types... a two RAM chip version or a single RAM (double capacity) chip version. Since the 29C has much more memory than the 25C, it used two of the double capacity chips.
Now the tricky part... there is a slight difference in using the two types of chips. There is a 100K pull-up resistor on one of the RAM chip pins (sorry, I don't remember which version uses the resistor and which does not). If you change RAM chip types in your machine you will need to either add or remove the resistor.
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