Connecting DIMM's to external power supply - Possible?

OldFoo · Post by **OldFoo** » Sat Mar 20, 2010 2:11 pm

Anyone have any how too guides on connecting NAOMI dimm's to extrnal DC power supply that can be left on at all time to preserve DIMM RAM?

I am getting tired of waiting for the checking ram, loading game, reboot sequence every time I want to play a GD-ROM game.

Leaving the cabinet on for 12-24 hour to charge the dimm seems like a awful waste of energy, I don't need the monitor and mb on, just want to keep the DIMM RAM in tact.

Any info greatly appreciated.

Thanks

Bob Presutti

OldFoo · Post by **OldFoo** » Sat Mar 20, 2010 4:24 pm

Technically speaking, if 3.3v is constantly supplied to the RAM, the contents will never be lost. On PC100 RAM, Pin1 is Ground and Pin6 is 3.3v. I would not suggest directly supplying power to the battery connector because it has a charge circuit on it and I don't know how it would react to the absence of batteries. If someone on this forum knows more about this, feel free to chime in. :smt023

OldFoo · Post by **OldFoo** » Sat Mar 20, 2010 4:38 pm

I am concerned as well about the charging circuit

Is this still the best thread for replacing battery with fresh battery and bumping up capcity to 2200mA?

http://www.sega-naomi.com/forum/viewtop ... ttery#1001

OldFoo · Post by **OldFoo** » Sun Mar 21, 2010 3:03 am

AFAIK, it sure is. :smt045

P.S.

What I meant in my previous post is, that if you supply 3.3v after the charging circuit that it should work. The charging circuit should be isolated from the memory section. I also mentioned the battery connector because I didn't want you to get the idea of connecting a power supply directly to that circuit. This, of course, means that you would need to find somewhere on the circuit board to connect/solder the power terminals. This would need to be done carefully as you could potentially disable the memory by cutting off the chip's supply.

OldFoo · Post by **OldFoo** » Mon Mar 22, 2010 2:27 pm

you can connect a 7.5V ac/dc converter at the Dimm boards akku connector.needs at least just apx 7mA current, so a very small ac/cd converter will do it. as the result you do not need a battery...