Redrawing the ROM map

There are several things people want to expand, and the reason I make this topic is to discuss what makes sense when trying to put together an expanded ROM.

As we all seem to agree that it would be a good idea to make some kind of open project to optimize and organize, there are a few ideas and observations I want to put out there before I forget.
Mon
First: Map expansion. I know it can be done, but I have no idea how to even begin there. I'm sure whatever kind of map data can be expanded would need a dedicated editor to handle it.

Second: Event expansion. The existing events in vanilla take up almost 3 whole banks. Moving the events would be a very difficult thing to do, as they are loaded from so many places. What I would suggest is to move anything out of CC and CD that are not events. The existing event engine can easily handle going into a 4th bank (since 3 is not a power of 2, this should be obvious). I believe CD holds (among other things) the dialogue pointers... which would be an easy thing to move.

Third: Code expansion (specifically the C1 bank). I think one additional bank of code would be all that is needed, although code can go anywhere easily enough with long jumps, provided you can find room for a function to pass the options through.

Fifth: Monster expansion. I don't know where it is without looking at the ROM Map, but I believe that adding monsters to at least 512 would be fairly easy in most respects. The monster data itself can be placed in a larger area. The sprites would probably be the hardest thing, and I'm sure that can be done as well. AI would probably need a new bank, but that's just one block of data and its pointers, so not too difficult (note that, without some code changes, monster AI scripts above 0x8000 in their bank will not trigger their counter-attack scripts properly, so a hack is needed there).

On my side, the things I've done so far are a bit of a mess since they were not planned ahead together. I'll just state what is the situation currently and I'll add more to this thread concerning planning when I got a little bit of time. See following threads for current expansions details.

Monster Expansion
I'm currently coding the editor (FF6EME), all the banks expansion will be selectable by the user (ExHirom as well).

Modified FF3se
Put stuff in $F1-$F2 with the help of a patch. Will be obsolete with FF6EME.

FF6LE+
Put stuff in $F6 to $FB with a patch. Need to be updated with selectable banks sikmilar to FF6EME. Could also add map data expansion in this version.

FF6ExpED
Selectable banks of expansion for code and data. Will be merged with FF6EME.

Difficulty settings Editor (planned)
Needs expansion banks as well. Will probably be an update of FF6EME in the future (not on initial release).

FF3usME
Allows $10000 bytes AI expansion (choice of $F0 to $FF) and dialogue expansion ($F1?). See editor for details.

More thoughts to come probably this weekend

I'll just add to what has already been said.

First: Map expansion. I know it can be done, but I have no idea how to even begin there. I'm sure whatever kind of map data can be expanded would need a dedicated editor to handle it.

FF6LE is open source so this can be done in a relative easy way. When I modified FF6LE to expand NPC, event triggers and exits, I've looked a bit into map expansion. All what is needed to be expanded is pointers, move map data (tiles data) and add a good space buffer for the number of maps you want to add and finally expand a fixed length data for each maps containing like which song play and other things. I think I'm not missing anything here.

Second: Event expansion. The existing events in vanilla take up almost 3 whole banks. Moving the events would be a very difficult thing to do, as they are loaded from so many places. What I would suggest is to move anything out of CC and CD that are not events. The existing event engine can easily handle going into a 4th bank (since 3 is not a power of 2, this should be obvious). I believe CD holds (among other things) the dialogue pointers... which would be an easy thing to move.

Moving dialogues pointers would save roughly 0x1800 bytes. Right after comes the dialogues themselves. The major drawback for this idea is that moving dialogues or even their pointers would break FF3usME dialogue editor. I believe PB added an extra dialogue bank and was obliged to use Atlas after to edit them. This is something that needs to be considered when touching dialogues or their pointers.

Third: Code expansion (specifically the C1 bank). I think one additional bank of code would be all that is needed, although code can go anywhere easily enough with long jumps, provided you can find room for a function to pass the options through.

I think moving the half of C2 like you said is a good thing. I don't know C1 really so I can't tell if part of it can be moved without too much trouble.

Fifth: Monster expansion. I don't know where it is without looking at the ROM Map, but I believe that adding monsters to at least 512 would be fairly easy in most respects. The monster data itself can be placed in a larger area. The sprites would probably be the hardest thing, and I'm sure that can be done as well. AI would probably need a new bank, but that's just one block of data and its pointers, so not too difficult (note that, without some code changes, monster AI scripts above 0x8000 in their bank will not trigger their counter-attack scripts properly, so a hack is needed there).

Yes, expansion up to 512 monsters is possible. There's a lot to move but it can be done without too much trouble. This is the first thing my editor will be able to do. As for the AI bug, does this mean FF3usMe AI expansion is buggy?

I told Lord J about the 0x8000 limitation on vanilla, so it's possible he includes a patch that will overcome the problem, but to be honest I haven't made enough/long enough scripts to get down that far in a bank so I can't be sure if it's working properly or not. I would suggest that if you compare an expanded AI vs. a non-expanded one, and it doesn't change a few bytes in C2, then the patch isn't there and counters won't work properly (or at all) for scripts beyond 0x8000 in their bank.

What a luck! i still have to apply the AI expand patch on CotG!
Said that, 0x8000 problem will probably affect my hack since it heavily relies on AI script(probably the core of my work)
So i'm looking forward a fix to that. 

When you say map expansion does it also mean making the towns physically larger? Because that would interest me a lot...

When you say map expansion does it also mean making the towns physically larger? Because that would interest me a lot...

No, it means more maps. What you describe is not possible if the map is at the max allowed size to my knowledge, even with a modified FF6LE. The small maps like single screen maps could probably be expanded but it's not possible with the existing FF6LE.

I see. Big sprawling cities would be nice. One can dream, I guess.

Well, it's quite possible to design cities that feel large using multiple connected maps. Kefka's tower or is a good example of many connected small maps feeling like one large place.
Rabanastre in FFXII comes to mind, too.

Well, it's quite possible to design cities that feel large using multiple connected maps. Kefka's tower or is a good example of many connected small maps feeling like one large place.

Why didn't I think of that.... alright, off to make Vector x2 larger