New USB reflashable EEPROM chip for SNES cartridge?

So I checked out http://hackaday.com/ like I do everyday and came across this interesting project:

http://electrifiedfoolingmachine.co/?p=571

The person created this to test hacked versions of NBA JAM for the SNES. It works by simply replacing the the ROM chip on the SNES NBA JAM cart with his version that includes a USB programmer. It should work with other game carts that use a single ROM chip and the game code agrees with the rest of the cart components. Very cool if you ask me. Not as cool as the Everdrive SNES or upcoming SD2SNES but still nice for those wanting to have a cheaper option and don't mind reflashing each time they change games. Should be available for purchase soon. If not, the build files should be available.

 

interesting design

 

This may sound like a silly question, but it is something that's always rather bothered me.
Why is it that SNES reflashables don't use a passthrough so you can attach a cart on top, allowing cart-specific chipsets?

 

Because it doesn't work that way.

 

Because it does not work that way for some chips.


When Nintendo learned that copiers were using the add on chips from cartridges, like for example the DSP chips, they changed the design so the MASK ROM with the game is connected to the expansion chip and maps through it, so you can't put another ROM on the bus in the outside of the cartridge since cutting access to the ROM chip inside the cartridge will at the same time cut access to the expansion chip register. Catch 22 here.

So things like Super FX, SA-1 and S-DD are designed in that way, making it go exactly as Ape say.

Still, older chips like the DSPs can be used that way with copiers, for example.

 

Bumping just to say this project was finished a few months ago, had all files released http://electrifiedfoolingmachine.co/?page_id=633

Shame he's not selling them premade, I'd probably buy one if it turns out SA-1 isn't possible on sd2snes

 

SA-1 doesn't use DIP MaskROMs. You'd have to solder it by hand with wires.