games using EEPROM for saving

games using serial EEPROM for saving

So I quickly tested a few games on this new acquisition and everything worked perfect so far, I'm very pleased.

Unfortunately, one of my favorite (Wonderboy 5) is actually freezing at the start screen and I think I know why since the exact same thing happened in Genesis Plus GX when I initially picked the project.

The reason is that this game (and a few others) is not using traditional SRAM for internal backup despite what the ROM header is indicating (well it indicates Backup RAM mapped between $200000 and $200001) but serial EEPROM which I believe is not supported by the Everdrive and cause the game to lockup. The lock-out can be fixed by forcing SRAM OFF but then you lose the ability to save your progress.

Some time ago I studied how this kind of EEPROM worked to add support in my emulator and I wrote a basic document explaining these stuff and listing games requiring EEPROM support, you can find it here if you are interested in adding this, I hope this can be done with only firmware modification , by simulating EEPROM behavior ;-)

PS: The game list given in the document is not complete, for a complete list check eeprom.c in the genesis plus sourcecode.

 

You aren't going to get SEEPROM emulation in a CPLD lol. Since you're technical, just hack the games to use SRAM...

 

i can't implement serial eeprom by firmware update. unfortunately eeprom saves will stay unsupported

 

noooo

please someone sort the wonderboy games out for sram saving
my most faviroute megadrive games ever
actually one of the resons i got the everdrive
and to find out they are not fully supported is :-(

would it be a simple proces for someone with the right skils to convert the rom file to use sram or a complete nightmare?

 

Here is a discussion and SRAM patch for Wonderboy in Monster Land http://tototek.com/phpBB2/viewtopic.php?t=2849&postdays=0&postorder=asc&start=0

 

cheers


ive just downloaded the sram hacked rom for wbimw

 

This is strange as Monster World 4 works perfect for me. I got to the first save point switched the power off and loaded it back up and it was fine. I wonder why that is. Maybe its because of the translation patch I applied, maybe the sram hack came bundled with it or something.

Edit: Oh my bad I belive I'm talking about the wrong game.:redface:

 

It would be hard to add the save state? could lower the roms and hacks when we want to save, not to mention the great benefit and perhaps the best feature of Everdrive.

 

Yes it would be hard. It might be possible, but it would not be something simple to add. And even if it were added the compatibility of it might be very poor.