Actually, go to $12352 in the rom and you will see this:  48 F0 28 64  The first byte is the screen number this tile will appear in.  F0 means that this tile will be removed in a linked game(I was a bit off with the values I mentioned previously).  28 is the location on screen of the tile, and 64 is the tile ID.  BTW, if the second byte is less than F0, then it will check for screen flags instead.  For example, if it was 80, then it would check for that flag in memory.  10 is never used because it's the flag that makes the room display on the minimap(which is why the game uses F0 to trigger the alternate check routine).

So what you may wish to do is you could use this value on any screen you want.  Just remember that it loads or takes away the tile(only F0 will remove a tile, the rest will add it in) when you screen transition, not in the midst of being on screen.

Are we talking Ages or Seasons?  For Ages, the Hero's Cave is actually blocked off by a specific tile that is only removed in a linked game.  There is a certain type of map data that ZOLE doesn't implement, and it's for single block additions.  How it works, is there is a spot in the rom that defines these blocks for each map.  There's room number, the block ID, it's location on screen, and which bits in the room flags to trigger it.  A good example would be in level 8, where you place the stone tablets into the wall to make the staircase appear.  Essentially, each time you return a stone tablet, you set a bit in the room flag.  In this case the tablets use the 4 bits used to keep track of locked doors(the lower bits).  The game will search for that bit, and if it's turned on, will add lit torches and a filled in wall in whatever side you placed the tablet.  Note that this only keeps track of initial screen loading.  There is a seperate thing that makes the tiles appear on screen during the event.

Another example would be the stones you see just to the left of the village.  How it works is there is a specific interaction that will check to see if a tile is distrubed.  If it is, it will set a bit you define in the room flag data.  Then, when you come back later, the stones won't appear again.  However, if this flag data is set to F0 or greater, it will instead check for certain conditions, mainly if the game had been beaten or if you are in a linked game.  One type will add a tile if you are in a linked game, and one type will remove a tile if it's a linked game.

In Seasons, it's different, but I'm sure has to do with the same concept.  Instead however with dealing with tiles, we are dealing with warps.  I don't think I quite figured that part out yet though.

Sounds like some event stuff going on.  I know I only told Lin about one byte that locks your buttons untill you get the sword.  Since I understand how events are flagged, I could take a look and see exactly what needs to be autochecked.  In fact I bet Lin's script doesn't even check the event off properly, instead just writing a bit directly to ram instead of using the proper indexing and sub routine.

Static objects are objects that are capable of traveling with you from one screen to another.  Carts, for example, will stay in the spot you last left them.  Furthermore if you were somehow to change maps(by time warping inside a dungeon), the static object would still be there because once it's been loaded, it stays untill you exit a dungoen.  Magnetballs in Seasons are also static objects.

Now while we are on the subject of interactions, there is one more bug to fix.  F4 control type currently does not recognize the pointer as a pointer, but as seperate pieces of data.  F4 basically sets bit 7 in the room flags once the screen is cleared of enemies(there is also an interaction that does this, but it could be that F4 adds that object automatically, I'll need to check).

I know the location of the control type pointers, so it's easy to check out what does what, or even be possible to add a new control type.

That's pretty good news.  A new Oracles level editor would be good as well.  I've been busy and I've discovered how the text events work as interactions.  Currently ZOLE misreads certain data formats and it could cause problems for people who do want to edit those events.  Currently I am trying to create a new interaction that would allow for the 4 dungeon staple items, keys, boss keys, map and compass to be more portable rather than rely on chest data.  Think about that.  Excluding keys, that could stand to cut as much as 96 bytes that could be used to add chests for other stuff.  There could even be a possibility of having multiple chests in a single room if I try hard enough.

Okay off the bat I noticed one thing wrong.  One of the treasure chests is positioned wrong.  Remember you can only open chests from the bottom, and if you try to from any other side, you will get a message that you can't open it from there.  I am sure that could be correctable, but in the meantime you need to position the chest so you can open it.  Second, oveworld chest space is pretty limited, and perhaps having two chests in the same area might be a bit much.

Other than that, pretty good.  As for dungeon, well you could make the map look like pixie wings.  I take it there will be multiple exits in the dungeon?  Will you keep the feather as the dungeon item?  If so remember that the feather chest data needs to be altered so it will come out of a chest.

The music in Seasons is totally compatable with the music in Ages, so it is very possible to copy/paste music between the files, provided you make a few alterations and find the extra space for each of the 4 channels.

Between two different games would most likely require you to re-compose the music.  I don't know anything about that, but what I can tell you is that in Ages, the music is at the end of the rom.  There are pointers that lead to the 4 pointers for each channel of music for within a song.  The data should be around E5000 somewhere.

How would you make a door open when a block is pushed?

You need to use interaction 1301 and place it over the block.  Note that what this does is when you enter the room, and monsters are still on screen, the block's ID turns to 1D, but the graphic is not updated.  When you set the clear monster flag(by beating all monsters), it will revert the tile back to what it's supposed to(with no on screen cue).  This means you can create a treasure chest that won't open when you defeat all enemies, or do other stuff.  If on a screen with no monsters, you could even make a bush, when cut, open a door.  Basically if the spot is distrubed, it will cause the doors to open.  Also of note is 13 03 will set bit 7 in the room flag data when all monsters are killed, and 13 04 will locate on screen, the nearest from the top, a certain floor that will turn into stairs and stay that way.  These certain tiles have one for acending stairs, one for decending stairs, and two wall tiles that become staircases.  I forget what 13 00 and 13 02 do.

Most of that stuff would need to be done by hand in a hex editor.  Having said that, yes it is possible, but you would need to familiarize yourself with Z80 ASM, find the code you wish to change, and make the changes.

If you want house tiles, you can change the tileset for each screen.  Note that Level 2's entrance will need to be put somewhere where it can use tileset 4 or else the entrance won't display correctly.

NPC's I haven't looked into, and there is a patch to disable the intro section with Impa.

Well I can't give specifics, but I do know where much of the data that's needed to edit the game is found.

0000 - 3FFF:  Main program bank.  Contains link to data found all about the rom plus monster and object pointers.

4000 - 7FFF:  Contains things such as the minimap data for dungeons as well as pointers for tileset graphics and othe things.

8000 - BFFF:  Not sure, but Maple's screen flags are stored in this bank.

C000 - FFFF:  Not sure.

10000 - 13FFF - Area header data, region map pointers, room alteration data(several types and includes level 7's flooding rooms(pits only) and polution cleanup as well as crystal switch effects)).  Also contains warp data.

14000 - 17FFF - Contains stuff related to player imput and weapons.

18000 - 1BFFF - Contains block interactions and other data.

1C000 - 1FFFF - Various ASM including some data for the Cane of Someria.

20000 - 2FFFF - Interaction and sprite ASM.

30000 - 33FFF - Contains specialized game specific scripts used in various events.

34000 - 57FFF - Contains more interaction and sprite ASM.

That's it for now

Well I discovered why the game uses 2 room index ram locations.  One is purely for level data, and one is for objects/warps and stuff.  When I altered the value so it read off of 30 CC, it didn't have that 5D limit that it does when it reads from 2F CC.  I am really not sure what's going on, but can you recall at any point where you might have AND'ed 2F CC for any reason?  How about how you stored the level data?  Did you store it in 256 k pages, or did you bunch them all together wihtout leaving any extra space?

Edit:  Okay I think I know the problem.  From what it looks like, your level data pointers cross banks, that is room 52 is in the high end of one bank, and room 60 is the low bank of the second.  The way you have it it works fine exept any time the game wants to swap one room for another, it reads the room data, but doesn't shift the bank.  This I believe, is why the game was programmed using relative pointers and if you notice, the level data often spans multiple banks.

I was looking at level 3's turnstile data, and there are two parts.  One part is what's responcible for the actual object and when it appears.  The other controls the map script and what changes are made when the 4 crystals are dropped.  The problem is that when I triggered the event, the room that's map 52(Monlight Grotto) becames one of the rooms from Present Maku Path.  I went and checked the script and there is nothing wrong with it.  What I did notice is that the game accepted from 00 to 5D regularily, but from 5E and onward, it repeats itself stating from 01 again.  This event is set so that map 60 replaces map 52 when the switches are broken.  Basically, somthing is happening that is making the game not read rooms greater than 5D and instead making it repeat.

The other thing is that the new room is offset by 16.  That is to say that the lowest 15 tiles are first, then the rest of the room so it looks like the bottom is up at the top and the bottom is missing.

First of all, make sure the door is set up correctly with the proper y/x.  If it's at the top of the room, it would be from 01 to 0D.  Second, make sure the door is set to open properly.  If it's a top door, and it's set to open when you defeat all enemies, then it needs to use 1E08, otherwise it won't open properly.  Also I do believe that if you have no door event and you enter a room on top of a door tile, the door tile should be removed.  I know in level 1 there is a door that acts like this that allows you to exit from the next room, but not to enter into that room from that direction.

I went to change the destination x/y for the warp on map 10(level 1) and not only did it somehow remove the warp, but it also seemed to mess up info for another side warp.  When I used compare to find and fix the data everything was woriking again.