12902Re: [cosmacelf] Re: The 1802 Elf and Serial EEPROMs
- Mar 21, 2013On 3/21/2013 8:06 AM, jdrose_8_bit wrote:
>> Another option is simply to battery back up your RAM, so it simplyIndeed, it was in one of their original articles. The circuitry needed
>> retains the data as long as the batteries last. With CMOS, this can be
>> many years!
> That is an interesting option. A CR2032 would probably be enough for a while. I am not much of an EE but I doubt that it would take a complicated circuit change to the PE ELF to do battery backup for the RAM.
is little more than the RAM, two diodes, and a pullup resistor on the
RAM's "write" pin so it won't accidentally float low.
On the Membership Card, I found that I didn't even need the diodes. I
could battery backup *everything*, and still hold data for a year on two
Anyone can make the simple complicated. Creativity is making the
complicated simple. -- Charles Mingus
Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
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