Converting PC MGS Master Collection saves to switch?

[LiquidPlazmid]

Has anyone else tried making their PC MGS master collection saves work with switch?

I've tried a few things with MGS2 and discovered a few things.
1. The PC and Switch saves are both broken up into their individual save slots 0,1,2,....
2. Each save slot has a 29KB "primary save". Both PC and switch have these files at exactly the same size.
3. In each save slot on PC it is just the primary save

and another file that may or may not contain data. On switch it is the primary save and 4 other files

I can confirm mg2.ico is the same exact file for every switch save and icon.sys differs only by one byte or so between saves.

4. The actual name of the primary save determines the save info on the title screen (difficulty, time played, date saved, room) this works the same on pc and switch and renaming a switch save to a pc save of mine caused the title screen to display the same as the pc save, even to the point of turning the save red dignifying the game was cleared and it unlocked boss survival.

5. On switch you can swap the primary save file into any other save slot and it will load completely fine in my testing. This calls into question what the purpose of the other files is even for.

6. Copying primary saves from pc to switch, replacing the old primary save in a slot causes the correct save to appear on the title screen, but it fails to load.


If anyone else has given this a shot or has done their own testing with different results feel free to share below!

 

[blashy101]

Has anyone else tried making their PC MGS master collection saves work with switch?

I've tried a few things with MGS2 and discovered a few things.
1. The PC and Switch saves are both broken up into their individual save slots 0,1,2,....
2. Each save slot has a 29KB "primary save". Both PC and switch have these files at exactly the same size.
3. In each save slot on PC it is just the primary save
View attachment 402041

and another file that may or may not contain data. On switch it is the primary save and 4 other files

View attachment 402042

I can confirm mg2.ico is the same exact file for every switch save and icon.sys differs only by one byte or so between saves.

4. The actual name of the primary save determines the save info on the title screen (difficulty, time played, date saved, room) this works the same on pc and switch and renaming a switch save to a pc save of mine caused the title screen to display the same as the pc save, even to the point of turning the save red dignifying the game was cleared and it unlocked boss survival.

5. On switch you can swap the primary save file into any other save slot and it will load completely fine in my testing. This calls into question what the purpose of the other files is even for.

6. Copying primary saves from pc to switch, replacing the old primary save in a slot causes the correct save to appear on the title screen, but it fails to load.


If anyone else has given this a shot or has done their own testing with different results feel free to share below!

Could you upload a couple example files for PC and Switch saves? I'd like to try and see how possible it would be to convert back and forth. Keep up Kojima's transfarring idea

 

[LiquidPlazmid]

Could you upload a couple example files for PC and Switch saves? I'd like to try and see how possible it would be to convert back and forth. Keep up Kojima's transfarring idea

Sure, attached is 2 files at the start of the tanker for switch and PC. The first file is taken immediately after we control snake. The second is after we fire 1 shot

Post automatically merged: Oct 31, 2023

New discovery to add to the list. Switch save files do NOT require the .meta, mg2.ico, or icon.sys files to load. If you created a save file on the switch and just delete those 3 files leaving the primary save and the empty file the game still loads correctly.

The problem with save conversion between PC and Switch lies within the 29KB primary save itself

 

[LiquidPlazmid]

Haven't updated this in a while but I've made several discoveries.

I cracked the decryption on MGS2 and MGS3 save files in the master collection by modifying an HD collection tool I found and updating it to work with the new save structure. https://github.com/mwoerner77/MGS-Master-Collection-Save-Decrypter

Switch saves and PC saves only have a 29 byte difference after they're both decrypted. I will continue to research how to port them, but will sit on this for a bit as I have other projects. With the saves I've attached and the tool I linked I'm sure someone dedicated can probably figure it out before I do. Just keep changing bytes until it works, then isolate the specific bytes that are needed. With this small of a difference it's probably something stupid like a single byte that changes based on platform.