Ha!  I bet you thought I was asking for help!

Anyway, since I haven't seen the game disassembled much, I though I'd find out where the levels are stored, and how they are compressed.  After about a day of searching, I found it.

So basicaly, how things work, is that at offset 2201a in the Rom, there is a list of pointers, except they are like relative pointers.  The first byte acts as usual, and the second byte is the page that's addressed.  The first room is 02 04, so that makes the offset 22412, with the header added.  This data leads to a second list of pointes that are also relative, with additional properties.

Rooms are assembled several pieces at a time.  For example, room $01 in the C-Island cave, shares some common data with room $02.  How it works is that each room has several pointers.  Room 01 has 3, and room 02 has 2.  Both rooms share a pointer to the top half of the room.  Like with the first set of pointers, these ones have a similar format.  The first byte + $10 is where on a given page the data starts.  The second byte has the page number, but the upper bits control, as it appears to me, how much of the data to grab.  In room 01, three pointers are needed, but in 02, only 2.  That's because the second pointer in room 02 also inludes data from the third pointer in room 1.  What's happening is that the pointers grab snippits of level data, and depending on if the room is finisted or not, there's additional pointers.  It's still not totally figured out yet, but it's getting there.

$22F0D in the rom is where the data starts for the first pointer in room $01(and other rooms that use this data piece).  The format is RLE, in different formats.  The first byte, 86, tells the game to place tile $00 6 times.  If $10 is set, then it will use that tile ID + 1.  The next compression format is simple, and always seems to start with a $20.  For example, 23 will tell the game to make the next three bytes tile ID values.  The third format uses $10, with the second nybble being the length.  This is used when the tiles needed exceed 7, because the one byte code only goes that far.  $1A 0A would place tile $0A, which is a normal walkable surface, 10 times, wheras DA would end up placing normal tiles only 2 times because bit $10 is used to toggle between ID value and ID value +1.

The last format, and one that's rather odd, uses the upper bits between $40 and $60.  When used, it seems to have a combination of two different tiles, usually water and steppable tiles.  For example, $62 tells the game to have a water tile with a shadow appear, then a steppable tile.  After that it's told to repeat the pattern 2 times, which makes 4 tiles appear in all.  $6A on the other hand, seems to do the same, except it's reversed.  If water came first, then this time the steppable tile would come first, then water.  The 2 bits, $40 and $20, seem to have 3 combinations.  I've seen shadowless water and shadowed water, shadowless water and tiles, and shadowed water and tiles.

So that's it basically.  I've also found the room headers and event data, but not where each room leads when you exit it.

I need to learn how to do this stuff. Jig, when you get all of this together, PLEASE contact me either here, AIM, or my e-mail (JustAnotherFace.Griff@gmail.com) and I would LOVE to make the first Star Tropics hack.

So now I need to figure out how the events data work, and also how the rooms are connected.  I'm actually thinking of doing  minihack, like a boss rush mode where you have to fight all the bosses room after room.  There is one thing I've noticed, and that is that the game has a ton of free space to create levels and whatnot.  In fact the game has more free space than is really physically capable of using.  Also, in the game, data is not in order.  The first room's data is near the end, and stuff at the beginning might be used for room $40 or somthing.  Quite disorganized.  It also does not use standard pointers in the least bit.

I mean that in that nothing is organized in a sensible format and that the entire game looks like it was put together as it seemed right.

Oh. That seems simple enough, actually.

That seems like an odd jump...

Wow. I look up to you. I mean, I looked up to you when you covered SM:R, but this is awesome. This is like, my oldest favorite game. I loved Star Tropics.