Save game backup/restore

Asmodeous · Post by **Asmodeous** » Fri Sep 07, 2007 12:34 am

I am looking to back up/restore the saved games on my NES games that still have some battery life left in them. I don't want to lose all the work I've put into them (my Zelda 2 cart is perticularly impressive). Is there any tool out there that is made for this ? The only thing I've been able to find is a copyNES. At this point I am almost ready to buy a copyNES kit and install it into my spare NES.

I was kind of hoping there would be a piece of hardware out there that I could connect to the save game chip and dump the contents and then write it back to later. I'm not even sure if the save game chips are standard or if different companies used different chips so I don't know how realistic this idea is.

I'd also like to be able to do this for SNES carts as well and obviously this will require a sperate tool. I have found various tools for the SNES carts but I'm not sure which piece of hardware would be most affordable/best suited to what I need.

blargg · Post by **blargg** » Fri Sep 07, 2007 5:35 am

Take a screenshot and then use a cheat program to recreate a nearly identical save game in an emulator. Though I do understand the difference of having your saved games preserved. I still have some from 10 years ago that I dumped off a few SNES cartridges when I was making a programmer.

Post by **tepples** » Fri Sep 07, 2007 5:47 am

blargg wrote:Take a screenshot and then use a cheat program to recreate a nearly identical save game in an emulator.

In Mario Paint (SNES)? Good luck

gannon · Post by **gannon** » Fri Sep 07, 2007 6:11 am

Can't you just hook up a voltage source to it while you swap the batteries?

rbudrick · Post by **rbudrick** » Fri Sep 07, 2007 10:45 am

gannon wrote:Can't you just hook up a voltage source to it while you swap the batteries?

Yep, you can, but that's not a great long-term storage solution.

The answer to your question is, no there is not something readily available besides the CopyNES that will back up and restore NES game saves. I dont believe any of the NES "copiers" even do it. I could be wrong on that, but I don't think there is. On top of this, I believe the CopyNES is no longer sold. However, someone here may have plans for a device+software that can do strictly save file backup and restore. I've never heard of anyone making such a specific device for NES, but I wouldn't mind hearing the opinions of those here as to its feasibility.

-Rob

Asmodeous · Post by **Asmodeous** » Fri Sep 07, 2007 10:52 am

I figured that there wouldn't be any tool for this. I have been searching on google for quite a while with no results other then the CopyNES. I have seen some SNES stuff that looks like I could use it but I'm not sure which one to use. Maybe I should ask that question over in the SNES section ?

I've read quite a few of these threads. I think kevtris still has a few boards for sale. I'm going to try sending him a PM if he doesn't end up posting in this thread to see if he still has a few boards lying around.

As for making an application specific reader/writer, does anyone know if all the save game chips are the same of if they used different ones ?

tokumaru · Post by **tokumaru** » Fri Sep 07, 2007 12:17 pm

Asmodeous wrote:IAs for making an application specific reader/writer, does anyone know if all the save game chips are the same of if they used different ones ?

I don't think the type of the chip matters much, they're just regular SRAM chips... The problem is how to read their contents while they're still soldered to the cart. Any EPROM programmer can read and write to RAM chips, but you can't just desolder them, or their contents would obviously be erased because there'd be no battery attached to them.

The only way to do it is using the address and data lines from the cart, but depending on the type of the cart, the addressing space assigned to the RAM chip may vary. In carts with 8KB of SRAM, I believe that this memory is always mapped to $6000-$7FFF, so you could just read all the bytes in that range. However, carts with more SRAM (32KB) still only use that same addressing range (which can only address 8KB of data), so some sort of bankswitching is used to set what 8KB block from the 32KB chip is seen at a time, and the command to do that may vary from mapper to mapper.

Jeroen · Post by **Jeroen** » Fri Sep 07, 2007 12:48 pm

You could solder the connections to pins that can plug into a eeprom reader/writer. Little work infact.

Bregalad · Post by **Bregalad** » Fri Sep 07, 2007 1:17 pm

You could buy a tool that grip the SRAM chip and then dump it with it or something (I know this exist).
Alternatively, just hook up a 5V voltage on the VCC/GND pins of the cart connector while replacing the battery. You'd want to found a way being sure all chips on the board are permently disabled trough their /CE line trough, because they could not like the floating adress and data busses while being powered (the SRAM especially).

Asmodeous · Post by **Asmodeous** » Fri Sep 07, 2007 2:14 pm

The DMS4 EZ mod chip for the PS2 uses these chip sockets that pop on top of the chip and have lead wires. If I could solder something like this to the correct chip and put that chip into a reader/writer then I would effectively have what I need right ?

Here is a link so you can see what I'm talking about:
http://www.dms3.com/cgi-bin/ezise/engin ... e=products

The sockets go over top top of the chips.

tokumaru · Post by **tokumaru** » Fri Sep 07, 2007 3:35 pm

I know my EPROM programmer (those cheaper ones that cost $45) came with documentation saying that it could test SRAM chips, and I can only guess it does that by writing data to it and reading back. What I don't know for a fact is if it can just read from it. I see no technical reason for this not to be possible, but does the software even have the option of just reading? If it does, I'm sure you could solder some wires from the chip and bring them to the EPROM programmer and read the data...

Unless I'm missing something... You hardware experts out there... would it be possible to read data from the chip with just the power of the battery connected to it, or would I really need the +5V? Do you think it would be possible to read from this chip if all other pins were correctly extended to the programmer?

EDIT: If this is all possible, maybe you wouldn't even need to solder anything directly to the chip and risk ruining the cart. If you find a socket with long enough legs you could solder the wires to it, and just place that on top of the chip, making sure all the pins are making contact, effectively making something similar to that PS2 thing you talked about.

Asmodeous · Post by **Asmodeous** » Fri Sep 07, 2007 7:18 pm

tokumaru wrote:EDIT: If this is all possible, maybe you wouldn't even need to solder anything directly to the chip and risk ruining the cart. If you find a socket with long enough legs you could solder the wires to it, and just place that on top of the chip, making sure all the pins are making contact, effectively making something similar to that PS2 thing you talked about.

Ya, that was basically the idea with sharing the mod chip stuff. I was hoping I could find some sort of socket like that and then hook up the save game chip to some read/write hardware that way.

Edit:
spelling

drk421 · Post by **drk421** » Fri Sep 07, 2007 7:27 pm

I use something like this:

http://www.smcelectronics.com/MSCAB03.JPG

The other end is a socket with pins that goes in a device programmer.

Asmodeous · Post by **Asmodeous** » Fri Sep 07, 2007 7:47 pm

NICE. Thats the kind of thing to use !

Does anyone know if the save game chips are all the same on different NES carts or if they are different depending on who made the game ?

tokumaru · Post by **tokumaru** » Fri Sep 07, 2007 9:25 pm

Asmodeous wrote:Does anyone know if the save game chips are all the same on different NES carts or if they are different depending on who made the game ?

If I'm not mistaken, the vast majority of games with 8KB of memory for saved data use 6264 (or similar) SRAM chips like this one, as you can see in the picture found here (the chip marked HYUNDAI).

What you may find out when you open the cart is that sometimes they use chips of the narrower kind, but all the pins still have the same functions, so all you need to do is get a narrower socket to place over those.

I'm not so sure about the carts with 32KB of save memory, as these are much less common. But I would expect them all to use the same kind of chip, probably one similar to this one.

I'm not aware of games that use chips other than those 2 kinds. In fact, it shouldn't matter much if the chips have different pin configurations, as long as the EPROM programmer you use supports the different types, in which case you can use the same "adapter" to read all of them, you just have to set-up the programmer to the correct type of chip.

Here you can find a list of chips supported by the Willem EPROM programmer. I just don't remember if you have the option of just reading the SRAM chip. Maybe you could download the software from their page and check if it's possible, before spending any money on this.

EDIT: Just for reference, here's a pic of a cart that uses the narrow type of RAM chip.