Extracting save data from a Pokewalker?

[Mogybus]

so I found this post on reddit of a guy with a houndoom in a pokewalker, but no cartridge to bring it into. So I was wondering if there was any way to somehow extract save data from a pokewalker, so I could try and save the houndoom. I also dont know if this is the best place to ask, but its the best place i could find

[Poke J]

2 minutes ago, Mogybus said:

so I found this post on reddit of a guy with a houndoom in a pokewalker, but no cartridge to bring it into. So I was wondering if there was any way to somehow extract save data from a pokewalker, so I could try and save the houndoom. I also dont know if this is the best place to ask, but its the best place i could find

From my understanding of how the PokeWalker works is that there isn't really a save file. When a Pokémon is sent to the walker the index of the Pokémon is set on the walker so it appears that the Pokémon is with you when in actuality the Pokémon is still on the game. That is why you can call the Pokémon back if the PokeWalker is lost or battery is dead.

[Mogybus]

4 minutes ago, Poke J said:

From my understanding of how the PokeWalker works is that there isn't really a save file. When a Pokémon is sent to the walker the index of the Pokémon is set on the walker so it appears that the Pokémon is with you when in actuality the Pokémon is still on the game. That is why you can call the Pokémon back if the PokeWalker is lost or battery is dead.

ah well that sucks...

so theres literally no way to bring it back?

[Poke J]

Just now, Mogybus said:

ah well that sucks...

so theres literally no way to bring it back?

Without the original game save it isn't.

[Atrius97]

18 hours ago, Poke J said:

From my understanding of how the PokeWalker works is that there isn't really a save file. When a Pokémon is sent to the walker the index of the Pokémon is set on the walker so it appears that the Pokémon is with you when in actuality the Pokémon is still on the game. That is why you can call the Pokémon back if the PokeWalker is lost or battery is dead.

That's not entirely accurate, yes a copy of the Pokémon does remain on the HGSS savefile, but there is essentially a partial clone contained in the Pokewalker data itself. You can do a key combo at the Pokewalker menu in HGSS to "recall a Pokémon" if your Pokewalker is lost or broken, because the entire "original" Pokémon is still in a hidden slot on the savefile, but there is something on the Pokewalker more than just the species index value.

If you test the Pokewalker using Spinda, you can see that the spot pattern is retained, as are form differences with gender and such for other species.

Spinda having the correct spots is important, because that means the PID value is also retained by Pokewalker, as that is required to render accurate spot patterns.

If one were to dump the RAM of the Pokewalker and recover that PID value, it could be used to reconstruct the Pokémon's Nature, Gender, IVs, etc. I'm unsure if Nickname, Trainer ID, Secret ID, Trainer Name, moves, level, etc. are also all retained, but the PID alone would be plenty to go off of.

18 hours ago, Mogybus said:

so theres literally no way to bring it back? (without the original savefile)

It looks like some other communities have done a significant amount of digging into Pokewalker hacking, like these two for example, they appear to have made some headway:
http://dmitry.gr/?r=05.Projects&proj=28. pokewalker
https://github.com/mamba2410/reverse-pokewalker
It would take some significant effort and some digging to find it, but it's in there... Somewhere.

Edited August 9, 2022 by Atrius97

[Poke J]

1 hour ago, Atrius97 said:

That's not entirely accurate, yes a copy of the Pokémon does remain on the HGSS savefile, but there is essentially a partial clone contained in the Pokewalker data itself. You can do a key combo at the Pokewalker menu in HGSS to "recall a Pokémon" if your Pokewalker is lost or broken, because the entire "original" Pokémon is still in a hidden slot on the savefile, but there is something on the Pokewalker more than just the species index value.

If you test the Pokewalker using Spinda, you can see that the spot pattern is retained, as are form differences with gender and such for other species.

Spinda having the correct spots is important, because that means the PID value is also retained by Pokewalker, as that is required to render accurate spot patterns.

If one were to dump the RAM of the Pokewalker and recover that PID value, it could be used to reconstruct the Pokémon's Nature, Gender, IVs, etc. I'm unsure if Nickname, Trainer ID, Secret ID, Trainer Name, moves, level, etc. are also all retained, but the PID alone would be plenty to go off of.

It looks like some other communities have done a significant amount of digging into Pokewalker hacking, like these two for example, they appear to have made some headway:
http://dmitry.gr/?r=05.Projects&proj=28. pokewalker
https://github.com/mamba2410/reverse-pokewalker
It would take some significant effort and some digging to find it, but it's in there... Somewhere.

Good to know. I wasn’t aware that The pattern on Spinda was retained. With that info defiantly a RAM dump can get the important info needed to reconstruct the Pokémon.

[Atrius97]

As a sidenote, this line on Bulbapedia makes me believe that even more data is stored by the Pokéwalker:
https://bulbapedia.bulbagarden.net/wiki/Pokéwalker#Other_Pok.C3.A9walkers

Quote

Similar to mixing records, once two players connect their Pokéwalkers, their in-game team data at the time they sent their Pokémon to the Pokéwalker will also be passed to the other person. When a player then sends their Pokémon back to their game, the person that they connected with and their team will appear in the basement of the Trainer House located in Viridian City, where they can be battled for one Battle Point once a day.

If this is to be believed, this would imply that the trainer data and entire party for the player is also stored by the Pokéwalker, because the game reconstructs a battleable version of the other player in the Trainer House. I suspect that would imply the Pokéwalker is capable of storing fully formed pkm data, rather than just partial pkm data, since it clearly can store an entire team of 6 from the player party.

[Poke J]

6 hours ago, Atrius97 said:

As a sidenote, this line on Bulbapedia makes me believe that even more data is stored by the Pokéwalker:
https://bulbapedia.bulbagarden.net/wiki/Pokéwalker#Other_Pok.C3.A9walkers

If this is to be believed, this would imply that the trainer data and entire party for the player is also stored by the Pokéwalker, because the game reconstructs a battleable version of the other player in the Trainer House. I suspect that would imply the Pokéwalker is capable of storing fully formed pkm data, rather than just partial pkm data, since it clearly can store an entire team of 6 from the player party.

I completely forgot about that aspect of the walker. I’ll have to check a RAM dump of one of my trainers in the Trainer House to see what the Pokémon data is like for these Pokémon.

[Poke J]

Upon an initial check of the data of Pokémon from the Trainer House compared to the actual data that is and isn't transferred to the Pokewalker is as follows.

Data that is transferred to the Pokewalker includes: PID, EXP (but if it has the Pokémon be above Lv 50 the Pokémon is rounded down to Lv 50), nature item, ability, friendship, IVs, EVs, attacks, TID, SID, and trainer gender.

Data not transferred over to the Pokewalker includes: origin game, met location, Poke Ball, met level, met date, fateful encounter flag, encountered on, egg met conditions, OT, and ribbons.

Data not checked includes: language, Pkrus flags, shiny leaf flags, nickname (but if my memory is right that data is transferred), contest stats, and extra bytes.

[Atrius97]

That's not surprising, sounds like they only really included stuff needed to properly recreate them as a mock NPC, and have the Pokémon appear with the correct battle values/shininess/form. The rest wouldn't need to be there since it has no bearing on a battle.