05191: megadriv [evander,wboymw]: EEPROM values not written for saved game

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
05191	Save/Restore	Major	Always	May 14, 2013, 10:25	Mar 23, 2021, 17:50

Tester	sbeasley2808	View Status	Public	Platform
Assigned To	Ryan Holtz	Resolution	Fixed	OS
Status [?]	Resolved			Driver	sega/mdconsole.cpp
Version	0.148u4	Fixed in Version	0.230	Build
		Fixed in Git Commit	19b9f02	Github Pull Request #	#7883

Summary	05191: megadriv [evander,wboymw]: EEPROM values not written for saved game
Description	Games that normal save progress to EEPROM do not save any file to nvram. A file called "mdslot_rom_eeprom_i2cmem" is saved but does not seem to contain any data for continuing on with EEPROM games. This bug also effects saving for Sports Talk Baseball and Wonder Boy in Monster World and possibly others.
Steps To Reproduce	evander: Start game, play game. Get to a point during gameplay when you are asked to save progression. After accepting the save progress the saved game data is not backed up. Starting the game again does not show "continue career". wboymw: Start game, get to the first inn, select YES-YES-NO (want to rest and quit after saving). Game is supposed to give a continue option after pressing start on title screen.
Additional Information
Github Commit

Flags
Regression Version
Affected Sets / Systems	megadriv [evander,wboymw]

Attached Files	0001.png (9,261 bytes) Aug 25, 2020, 01:05 Uploaded by Andrew sporttbb

No.09488 etabeta Developer May 14, 2013, 15:48	true. through the debugger you can see that data is written to the eeprom when you save, and such data is saved and reloaded when you restart the game. but then the game ignores the data, as if it had been written in incorrect format and if it assumes nothing valid had been saved.
No.11813 byblo Tester Jul 3, 2015, 12:23	Here, for the case of Wonderboy in monster world (wboymw) the file is written, but without any valid datas... (only contains 0xFF values) Also, why is a folder created, with inside a weird name without any extension? --> \nvram\genesis\wboymw\mdslot_rom_eeprom_i2cmem (128bytes) As comparison, In the case of Monster World 4, the file is correctly saved as: \nvram\genesis\mworld4.nv (1024bytes)
No.16230 Kale Developer Mar 9, 2019, 14:14	Monster World 4 uses backup ram iirc, so it's not relevant to games using i2c eeprom. The full list where an i2c is hooked up can be seen in hash/megadriv.xml, finding for "slot=rom_eeprom".
No.17907 Andrew Tester Aug 25, 2020, 01:04	Still an issue with sporttbb in 0.223. Unable to start a game. Get "EEPROM ACCESS ERROR" after selecting START and a couple of seconds following "NOW CHECKING DATA". See snapshot.
No.17926 Heihachi_73 Tester Aug 30, 2020, 11:36	Yep, noticed my saves weren't working when I was adding a few Mega Man: The Wily Wars cheats last month (the game didn't save anything at all, not even when beating a Robot Master), mentioned it on the MAMEWorld forum a few weeks ago but didn't think much about it at the time. https://www.mameworld.info/ubbthreads/showthreaded.php?Cat=&Number=387515