You mean in real time?
You want the game to read/write to SD card while playing instead of using the internal Wii memory?
Yes, it's possible using Emulated NAND.
There are three different Emulation method:
1. neek method: All the wii is (re)booted in emulation mode. it acts like a real wii, but ALL the Wii memory is located on your SD: channels, settings, mii, savegames, IOS, etc.
2. cIOS FULL mode: The wii is still running on the internal memory, but all access to NAND is redirected in real time to SD. It's less compatible than neek method, but works for most games. it redirect everything: channels, settings, mii, savegames, IOS, etc.
3. cIOS PARTIAL mode: The wii is still running on the internal memory, but access to NAND is redirected in real time to SD ONLY for specific path (Which is the savegame path). All other data are accessed from the internal memory: Settings, Mii, etc.
If you want a quick and easy way to save to SD, use an USBloader and search for the option to use EmuNAND for savegame to partial.
For example with USBLoaderGX:
- Default path is SD:/nand/
- you can change the path in the settings>user paths>EmuNAND save folder
- To enable it, you can do it globaly for all games or individually per game:
- global:
Settings > Loader settings > EmuNAND save : Partial
- Individual:
Select the game > Preferences > Game settings > EmuNAND save : Partial
Launch the game and it will save to the path you defined.
If you already have a savegame on your Wii, you can extract it to the EmuNAND path to continue your game progress instead of starting from the beginning:
Select the game > Preferences > Extract save
or globally for ALL games
Settings > Features > Extract all saves
There's no option to restore the savegame back to the Wii from the loader.
You have to use SavegameManagerGX to extract/restore saves from SD to Wii