NES Battery PCB

I'm planning to make NES Battery PCBs to extend TSROM boards and convert them to either TKROM or TNROM. However, I lack skills and knowledge with Eagle or any other PCB programm.
I'd then like to submit the files to OshPark, Itead or any other good PCB production company with a reasonable price, preferably Oshpark anyway.

Anyway, if someone would be so kind and make the Eagle files for me so I can submit them and produce PCBs that'd be great.
Here's the schematic I came up with:

EDIT: Fixed Connection.

That's ... confusing. And wrong.

Use this:

Diodes are 1n914, 1n4148, or any other cheap signal diode (you only need ≈50mA ampacity), capacitor is >4µF.

Also, don't connect the CIC to the battery switchover circuit, it doesn't need it.

Given how simple this is, and the amount of rework needed on the PCB, it's kinda hard to justify a PCB instead of just a tiny bit of perfboard.

Well, it doesn't need to be connected to CIC Pin 1 (which was wrong since it should be the 16th pin) but the original circuit from SNROM did that, too.
WRAM Pin 28 or any other VCC will work, too.


I know that perfboard works fine but I want to get started making PCBs myself and learn more about Eagle, so why not?

No it doesn't. Did you confuse CHR RAM and PRG RAM?

Anyway, here's a corrected version of your schematic:

No, I had the board upside down. Brain error.
Thanks, that helps.

I think only one resistor is needed, so I suggest this one :

Farid has the best answer IMO. That is the method I also use.

Alright, thanks!

Hey Ice man.
The diagram Farid Shared is what I have found existing on most official carts. It works but is not ideal since the carts do not contain a low-power reset IC like more modern carts. This is why Every battery backed cart for the NES demands that you hold the reset button down while powering off. As you know the Sega genesis carts for example, have the BA6162.

It does work though, so why over complicate it?