Battery Switch-Over circuit
2004-08-30 by wulffert
The battery switch-over circuit (Q55) sucks. I tried a NVRAM, removed the stupid button battery. The Q55 circuit cannot provide the right voltage to other types of RAM (ie Dallas ds1245y http://pdfserv.maxim- ic.com/en/ds/DS1245AB-DS1245Y.pdf). I basically fried the new RAM and found the problem lies with this circuit, I was actually starting to see some LCD activity, until the NVRAM bit it. I will post the mod at a later point, this will allow anyone to replace the stock RAM 681000 (which is hard to find) with a Dallas/Maxim/Simtek variety NVRAM (plentiful). Later