Save files dumped with Retrode 2 doesn't work

[Wannado]

Are you saying the Retrode can corrupt some saves? O_O
I've had zero problems with snes so far and I've used it on almost 20 games with saves.

In general, there's always some risk. But in this case, I was talking about a firmware modification that I have not released yet, and about a specific type of GB cartridges (note that the OP refers to SNES and GB games). The whole story started in replies #3 and #7 of this thread.

The currently released firmware versions, including the recent v0.18d-beta3, do not detect the SRAM in MBC2 GB cartridges, and so they do not enable it. That has probably prevented corruption of MBC2 SRAM so far.

Access to SRAM on other GB (Classic) cartridge types seemed to work in my (few) tests.

[Nori]

So if I try the cart and the save loads fine all is alright? Are there signs when the save is corrupt or does this mean it might work fine but it may have altered aspects of the save such as items or other elements? Sorry if this sounds very noobish I'm not an engineer and not familiar with how all this works.

[Matthias_H]

So if I try the cart and the save loads fine all is alright? Are there signs when the save is corrupt or does this mean it might work fine but it may have altered aspects of the save such as items or other elements? Sorry if this sounds very noobish I'm not an engineer and not familiar with how all this works.

We're not saying the Retrode will corrupt some saves, but we do say we can't guarantee you will never lose data (since there is no way on earth to guarantee that from a technical point of view). Look in the manual; you agreed to live with this possibility (however faint it may be) by using the device.
If the save loads fine, still doesn't mean it will still be there next time. Make regular backups.

[Nori]

I see. Thanks for the tip. It's a fantastic device.

[KingMike]

Test game sounds like Final Fantasy Adventure (/Seiken Densetsu/Mystic Quest).

I think MBC2 also has a write-lock function?
I know in emulators, saving in Aretha I (Japanese-only RPG) seems to only work in BGB, and only if RAM lock emulation is enabled in the accuracy settings. Otherwise when trying to load a savefile causes terrible game-breaking corruption (I think in some emus, even saving the game causes the corruption to happen instantly).

[Wannado]

I recently managed to get SRAM writing to work on the MBC2 chip. Due to confusion about which bit of a port was assigned to which cartridge pin, the Retrode was pulling /RD and /WR low at once when trying to write, causing the write to fail on MBC2.

The corruption remains, but I found out what is causing it: When trying to disable SRAM (so as to protect it from corruption), the value supposed to be written into the respective control register ends up in SRAM itself.
It is possible that this corruption also happens on games with other MBCs, not only MBC2.

I'm confident I'll be able to fix this soon. Then I'll prepare another firmware release.

[Wannado]

I fixed the SRAM corruption bug, and I confirmed that it was not limited to MBC2 games. It seems to corrupt only few bytes though, and if you're lucky, your savegame does not use those.

This bug fix is included in v0.19 beta, which will hopefully be published soon.

[MasterOfPuppets]

I fixed the SRAM corruption bug, and I confirmed that it was not limited to MBC2 games. It seems to corrupt only few bytes though, and if you're lucky, your savegame does not use those.

This bug fix is included in v0.19 beta, which will hopefully be published soon.

Great to hear!