Persisting cartridge writes?

[HitoriSensei]

Hello 👋

I've just started exploring this little Atari 800 XL computer and I find lots of really amazing software and games created for it. I probably would never have a proper chance to do so if not for this core and the MiSTer ecosystem, this is really amazing!

One thing that I find missing is persisting the writes made to the cart. I'm not sure how much software uses such method, but one game that certainly does is Flob: https://bocianu.atari.pl/blog/flob

I've found out that every time I hit reset all the progress is cleared. I've read on the author's page that the progress is actually saved of the cart itself, but it seems that the writes made to the cart are not persisted back do the microSD cart file.

Do you think it's a feature possible and worth implementing?

[woj76]

Worth implementing - probably (something I'd love to have too). Possible - I guess, but rather difficult, requires a whole new module in the cart emulation subsystem to emulate the flash writing. This is difficult enough that hardly any of the cart emulators out there do it, the only exception is AVG/SUB cart and it only does it for AtariMax 8Mbit carts if I understand it correctly. Also not in a direct way, it just piles up the written changes in RAM and asks the user for "permanenting" the change upon next cart boot. (And I am quite sure the author of that is not going to share the implementation, even though this is also done on an FPGA).