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View Full Version : Research/Survey: [R\B] Pokedex Expansion


80C
June 3rd, 2013, 02:07 PM
In Pokemon Red\Blue Pokedex Data is stored as bits in RAM areas.

In RAM Bit 0 represents that the current pokemon has not been seen/owned, while bit 1 represents that the same pokemon has been seen/is owned.
Actually, as the ROM originally is, 152 entries could work because 152 is a multiply of 8, so the max number of Pokedex Entries must be a multiply of 8.

What I'm trying to do is Expanding the max amount of Pokedex Entries, allowing a larger amount of entries.

A ROM expansion could be handful for this job, but the problem is the repointing of the RAM Areas, (RAM banks are between A000-BFFF), the problem is where I could store the new entries and make them work correctly.

That's the only problem for now, If I get new results, I'll elt you know.

LudicoloDude
June 10th, 2013, 04:24 AM
This is cool, I have always wanted to play a first gen game with more than the original 151 Pokémon. I know this next question is a bit off topic and might be on a forum somewhere, but would it be possible to add EV's and IV's to the game like third gen and higher?

A Sunny Moo
June 11th, 2013, 10:57 AM
Ludicolo, the problem with this is that the EV's that you gain from another Pokemon is a value that is stored with the Pokemon. The OP is already dealing with a limited amount of space for each Pokemon entry. I don't know if there is a limit on the amount of data that can be stored in a Pokemon's entry, or if it can be expanded, but I know that storing EV information would take more than just a couple of bytes of information.

80C
June 21st, 2013, 05:37 AM
I wasn't asking of IV's and EV's, I was asking how's possible the repoint of the RAM areas in RED\BLUE so it's possible expand the Pokedex up to 152 - some will say:<< throught asm.>>
<<ohoh... thanks>>, but saying "asm" doesn't solves the problem, infact a hex-editing operation is needed in order to move the RAM areas.

The ROM expansion is very useful, and the new banks could keep the new RAM Areas, the problem is the pointer - editable also throught asm - of course - but isn't needed only change the Hexnumber that points to the Banks\adress in which the RAM areas are located?? (after the moving of course).

someone then may say <<you have to do a disassembly>> I already saw someone trying that, but I noted also he was able to add only a pokemon #152 (like I did only by hex-editing) while the other entries were totally ignored by the game.

say only <<hex editing>>, <<asm>> or <<disassembly>> isn't the solution, - and learn asm doesn't mean that then you don't have to hex-edit anymore at all.

ShantyTown
August 28th, 2013, 10:35 AM
I'm working on a Red Version hack right now, and I've successfully extended the Pokedex past 152. There was some discussion at Skeetendo that helped me understand what needed to be done.

As you said, the location in RAM for the "seen pokemon" (0xD30A) needs to be repointed to somewhere else in RAM that has more than 19 consecutive free bytes. I wasn't sure which, if any, locations in RAM were unused by the game. I got around this issue by decreasing the number of Pokemon stored in the player's PC Box from 20 to 19. The 20th Pokemon slot in the PC is at RAM location 0xDD09 and goes until 0xDD29, so that gives us a total of 33 free bytes for "seen pokemon". Of course, you'll have to go through the ROM and limit the number of pokemon in the box to 19, instead of 20. This was fairly straightforward, given the red version disassembly project.

Note that there is no need to repoint the "owned pokemon" RAM location because the "seen pokemon" RAM data is located directly after the "owned pokemon" data. That means that the "owned pokemon" data has an extra 19 bytes to work with after moving the "seen pokemon".

Hope this helps!

80C
November 8th, 2013, 03:31 PM
Oh my dog!
I forgot about this thread!

I have to say that I laready fixed that problem since October and I've finished to fix it this month.
Now I could keep 248 Pokemon in the pokedex.

Once my hack is finished, I'll spoil some information about Pokedex Expansion + some information of how to push the Red ROM out of its limits.

Check it out then!