Conker's™ Hyrulian Tail ~ Screenshots and Videos!

Nice! Everything works perfectly good now! The only missing thing will be to implement the space suit thingy now (euclid has to find a way so that all those space areas deplete your health by default when you don't have the space suit [moon pearl] and once you get it, you change into space suit link [bunny link])

Ok but I'd still do it way round since you won't have the possibility to use items/sword when bunny... please reconsider since the overworld might be boring without these abilities - in the end it is just tile replacement.

Edit: Further, you will be bunny link in any cave/dungeon you enter. I do not know how a possible solution might end up with the current asm. I'd need to code every room entrance as exception you enter from space (and possibly all further rooms you enter in that cave/dungeon, remove the bunny code and re-give it when you leave...   wouldn't it be possible to take just normal ALTTP tileset and give a helmet on each head? This really isn't much work and will solve all problems...
 

About the music patch you sent me, does it allows me to have the correct music to load in all of the overworld areas? That would be sweet since right now, even if I change the music of each area in the properties and exit outside... the game still loads the main overworld theme by default and switch over the song I selected when I go out of that area and come back. I'll check your patch if it fixes that bug!

Yeah, no prob with my patch... the only thing you need to know is that you need to change two tables (instuctions in my mail). Also, I only implemented kakariko (girl), overworld (boy), skull wood (PW Link), Lost Woods (Minish) and darkworld/bunny (space). If you wish other music let me know, since I'd need to adjust my patch then and send you a v3 - list of possible themes in my above post (overworld only, I could also use other themes from indoors/endings but this more difficult since the music bank needs to be switched).

You can make it so that you're always AST boy when entering them! Since they are all part of the same dungeon and it connect with the center of the universes (The rift) so it would make sense to always be ast boy in those transition caves

Ok, that simplifies things. Could you give me the values of all entrances you enter from the other area?
E.g., from rift to space no change needed (you are boy), but from space to rift you still be spacelink - it is from this side entrance 17 and I must use this number as exception.
It is given in your pic, but some are concealed... could you write down all numbers?
It is 02, 17, ...

^^Good reconsideration, took about five minutes of copy and paste! I'll keep bunny Link as is, so when you get the Space Suit (which I'll rename "Space Helmet"), you are able to breath in space! Keeping the bunny will also prevent cheaters from accessing the other dungeons! Their health won't deplete if they use the infinite health but they'll still be blocked. Thanks for making me reconsider, one less problem to think about

About the music tracks let me think about it (a day or two ~ last day of work tommorow).

And for the transitions:

Rift/Modern World = Entrances 0E and 0F
Rift/Wastelands = Entrances 10 and 11
Rift/City of The Gods = Entrances 12 and 13
Rift/Space= Entrances 14 and 17

Thanks, this is great :)hacking this would have been a pain ^^
Further, if all tilesets are changed people may wonder why e.g.,  keep PW Link in city of god area dungeons but won't keep the helmet in space dungeons... makes my work also much much easier *happy here :p

Only some small suggestions, since all Links are different. I think it would be awesome if you'd take the ALTTP tileset instead of the boy for the space helmet. Then all Links are different and also native Link is also part of your game
Further, I do not know whether lightblue/purple fits better than orange for the color (glass!). This also gives more contrast to the skin color (which is the same as the glass in your above posted pic).
Perfect were if you could also add some reflections, that slightly alter when you move to imply the expression of movement; here's a mock up pic how I'd imagine similar to the original posted some posts ago:



Regarding the bunny look I'd suggest giving him the look of Link holding breath. I'm really not that good in pixeling so this is just an example how I'd imagine:



As for the music patch, there's an adjustment anyway (want to not overwrite the not move when charging the sword what I hacked for puzzle) so I make a v3 anyways. I wait until you give me instructions here.

For the transition exceptions are
Start Room: 02
Modern World: 0E
Wastelands: 11
City of Gods: 13
Space: 17

I need only the numbers when you return so that you are boy in the transition caves. Please check these numbers if they are ok (especially the girl).

Edit:
Think I got it. Please use the zip file of my second mail to test it (mtranv6 for bunny and transition caves; musicv4 for music and startscreen tileset).
Also you could now use the hack to won't be able to move when charging your sword if desired.

SePH wrote:About the music patch you sent me, does it allows me to have the correct music to load in all of the overworld areas? That would be sweet since right now, even if I change the music of each area in the properties and exit outside... the game still loads the main overworld theme by default and switch over the song I selected when I go out of that area and come back. I'll check your patch if it fixes that bug!

Not really a bug. It is hardcoded so that all entrances in the light world will play the Overworld music, when you exit them. There are only 3 exceptions (cave in the village, autoplays village when exited), and 2 caves in the forest (play forest music when exited). I had quite some trouble with that, but the only solution I could find, was to put a lot of caves in the GoT forest to lower volume (same solution in Alttp in the village). Which means you can not have a dungeon entrance in the area, where the Overworld music is not selected. Similar in the dark world. It seems like original authors had some touble with that also.

Conn wrote:Regarding the bunny look I'd suggest giving him the look of Link holding breath.

Fantastic idea.

Not really a bug. It is hardcoded so that all entrances in the light world will play the Overworld music, when you exit them. There are only 3 exceptions (cave in the village, autoplays village when exited), and 2 caves in the forest (play forest music when exited). I had quite some trouble with that, but the only solution I could find, was to put a lot of caves in the GoT forest to lower volume (same solution in Alttp in the village). Which means you can not have a dungeon entrance in the area, where the Overworld music is not selected. Similar in the dark world. It seems like original authors had some touble with that also.

I used a trick to avoid that issue: whenever you exit an indoor or warp with the bird, $012c will be set to zero. This is here:
$00/8100 9C 2C 01    STZ $012C  [$00:012C]
from here I hacked first a jsr (jsl is not possible, because it must! be 3 bytes only) to same unused space (same bank) where I already coded your no move when charging sword and from there a jsl to more free unused space in another bank. Here I coded a table to select the desired overworld theme in depencence on the screen you are ($040a). Works fine. Problematic with this patch was that in PU every screen you change is mosaic (there are 2 ways a screen changes, one where just the screen is moved and one where it gets diluted by mosaic as when you enter lost woods). To avoid an awful music reset every screen I found a table beginning at pc 01/4343  - here you need to paste exactly the same music themes as in the theme select table to avoid music reset.

Edit: urgh, found another bug: when dying in an area you'll start over as the link in the area you were... SePH, I'll fix it along with the music patch as soon I know which music you like.

Well for the space bunny thing, I already inserted the Zelda 1 sprite which ghillie made for his Minish Cap sprite and will add this nice little text in the room before you get to the space area:

^^^^^^^^
WARNING!
^^^^^^^^
DEEP SPACE BEYOND THIS POINT
LACK OF AIR MAY CAUSE HALLUCINATIONS AND EVEN DEATH
ALWAYS WEAR PROTECTIVE SPACE EQUIPMENT WHEN VENTURING INTO HOSTILE AREAS AS SUCH!

- The Weyland-Yutani Corporation
 "Building Better Worlds!"

(yes alien movies, I'm looking at you!)

The hallucination in question:



That's similar to Super Mario RPG otherwise when Mario transforms into 2d mario from the nes era! Also means I won't have to create/modify the sprite further and makes a nice cameo of the original Link sprite

About the reflections and using the LTTP tileset I completely agree but as for the colors I'm not really sure I can do much since the palette is all used already and I don't want Link to have his hair dyed pink like in LTTP. But I'll see what I can do about it.
(Probably remove one shade of brown since two very similar colors are used up and make one of them purple )

About the music, I'm still undecided as to what tracks I should *definitely*use, but so far I see no problem with your choices! They all fit the areas in which you put them! The Kakarikko village music for the modern world for example, is a nice choice btw!

*lol, whoopy that's a nice solution for bunny as well ;)Awesome!

I agree with that pink hair... you can also set the helmet color to white. This you have in any case for the eye color (but donno how this interacts with the reflexion). Then you may have grey, light blue... I'm sure you can make something amazing here ... but orange really looks strange.
Oh and don't forget to make the reflexion shift slightly with movement, this makes walking more authentic!

I think
boy-overworld is ok
girl-kakariko is perfect (thanks btw
space -bunny/darkworld is ok
PW Link - skull woods is perfect
Waste lands - lost woods - dunno so really. Rain doesn't fit, introduction neither. I chose this because I associate minish cup Link with woods. Also there are some strange fairies that fit to the music as well ^^

Ok then, I send you my final versions in a second (bug fix when dying in an area to start in cave 02 as boy again and not as the character as you died).

If there is a change needed sometimes I can still go for it

Thanks that should do it for now

Take another vacation from hacking this game if needed, you've been so much helpful lately! You've expended all our games in so little time, no need to rush the remaining energy you have yet! Thanks again for both the items change and the sprite change, they really helped me regain my full focus on the hack! If I ever find another small hack to implement, I'll know who to ask first

I try not to overuse Euclid's help either because I know he's done so much already aswell and everybody needs breaks from romhacking that game from time to time (I'm not an exception to that rule). Of course feel free to continue helping others for as long as you want, but for now I have no more requests regarding my hack as it's advanced well enough

Overworlds: Mostly done
Dungeons: Will all be done by the end of the year
Story: Currently working on it, should be mostly done by the end of the year
Sprites (new gfx): will add new bosses, but will keep general ones mostly like they are right now
Music: have no idea about potentialing whereabouts but only really wished for the resident evil evil mansion main theme, otherwise everything else can remain the same
Credits: working on a full list
World maps + menu screens: will only take one day, so no big deal
Other asm hacks: lost woods areas like in PW and space areas deplete hearts when no space helmet (Euclid will implement these)

Next year, implement Puzzledude dungeons (easy enough with unlimited headers!), foolproof monologue, betatest, bugfixes, add dungeon maps (when euclid is done with them), last minute changes and final asm if needed... release! Then using final version, RedScorpion can create a german translation if he wants

So there you have it, less then one year and my nightmare will be over (ten years hacking any game is well enough, I think you already agree with that fact Conn lol).

*haha, you're very welcome

So there you have it, less then one year and my nightmare will be over (ten years hacking any game is well enough, I think you already agree with that fact Conn lol).

I completely agree :p
But there's light at the end of the tunnel of your project ^^

I once hacked a different spc as well into bszelda, was... sorry: a pain in the ass to implement, and without wiiqwertyuiop apu tracing ability I'd have been lost.
midi must be converted into tracker and then into spc. I needed to rehack the complete load instruction.

Maybe there's an more elegant solution. Since my patch also isn't perfect (there's a small waiting time until the new spc is loaded into apu where the game freezes for half a second).

Do you mean you've been converting midi tracks into spc then added them in game? How long did it take to get it all done? (I mean that thread goes from 2009 to 2013 lol)

It didn't take so long time actually. The breakthrough was when FirebrandX filtered the wav from the original playing videos we got:
https://www.youtube.com/watch?v=nJ0IwiN0tyo

This wav was converted into midi (e.g. anvil studio), converted into tracker (.it) using openmpt, converted into spc (it2spc) and pasted into rom.

forward until the first waitsigns appear at 0:10 and you'll hear my inserted spc (the best I could do out of it). You'll notice also a short freeze at the start and end where the spc is switched.

That's amazing actually! Can the same process be done with Zelda 3 actually?

Would already converted midi tracks work already or do you really have to take a wav/mp3 track beforehand?

I'm just asking since custom music in Zelda 3 is so rare...

..not that I would mind actually having more then two custom songs lol

No, every midi should work, and this even is better since my skills are... let's say limited creating a midi out of a wav myself. There are however some instruments that aren't supported by Nintendo's spc engine (church organ, e.g., but you can exchange most instruments with similar ones that work).

It should work also with Zelda3 but from the coding side it is a nightmare, I can tell. I think it was 3 weeks coding until I got it work  

But I can give it a shot.

Alright I'll think about some custom tracks and I'll write back, but that'll be another day since I'm going to visit my grandmother who has come to visit us at my aunt, being recently widowed I'll take some more time with her

Don't exhaust yourself!

ah, I remember one thing: if I overwrite the spc, everything is overwritten, so you will not have any sfx anymore. Guess my hack is thus not an option.

But it is possible to edit midi into your rom using HM:
https://www.youtube.com/watch?v=zo1apIVXPhk

You can simply replace spc not needed (like beginning, rain) and give it the resident evil mansion theme. I already checked it out but the way HM displays the music sort of confuses me. Is there anybody here who already has some experience?
I think though it isn't that hard. Each track is divided into different parts. Every part has 8 tones (snes can't play more than 8 different tones at one time...) so it's only needed to know which instruments are used, which tones and which duration  (midi editor), then you can hack your custom music inside.
Edit: a good part can be viewed in openmpt:


Do you have a midi of the theme you want to have included?

Couldn't decide on a specific track so here's a small list of new music I wouldn't mind to have in the hack

Of course at this time this is more like a wish list since it would made amazing to have music tracks from the nintendo universe across all parts of the hack. Mostly Zelda related but other like a star fox song for the space area and others like final fantasy 7, 9, metroid and some megaman x mini song to replace the master sword song lol

BANK1:
======

1 - Title        = http://midi.thehylia.com/midifiles/gba/metroid-fusion/title-screen.mid
2 - World Map    = http://midi.thehylia.com/midifiles/ps1/final-fantasy-9/alexandria-2-.mid (MODERN WORLD)
3 - Beginning    = http://midi.thehylia.com/midifiles/gamecube/zelda-the-wind-waker/hyrule-castle.mid
4 - Rabbit       = http://midi.thehylia.com/midifiles/nes/legend-of-zelda/overworld-2-.mid
5 - Forest       = lost woods / by potentialing
6 - Intro        = http://midi.thehylia.com/midifiles/ps1/final-fantasy-7/the-forested-temple.mid (RIFT)
7 - Town         =
8 - Warp         =
9 - Dark World   = http://midi.thehylia.com/midifiles/n64/zelda-ocarina-of-time/gerudo-valley.mid (WASTELANDS)
10 - Master Swd  =  http://midi.thehylia.com/midifiles/snes/mega-man-x/stage-start.mid (MASTERSWORD)
11 - File Select =  http://midi.thehylia.com/midifiles/gameboy/legend-of-zelda-link-s-awakening/overworld.mid (CITY OF THE GODS)
12 - Soldier     =  
13 - Mountain    =  http://midi.thehylia.com/midifiles/snes/starfox/map.mid (SPACE)
15 - Shop        =  
16 - Fanfare     =  

Choose any of those you like, I'm certain some of these should be easier then others.

I've sent you my latest rom also!

:affraid: 
oh well... I guess somebody has to write a program to convert these midis into a file that can be included in HM. It may be doable by hand... but
Read this tutorial how you may achieve... I think we need Potentialing here

http://zeldix.forumotion.com/t154-the-music-tinkering-thread#1295

I received your rom... I was not able to hear a fog sfx in area 00 and couldn't trace a sfx (usually written to $2141, $2142, $2143). Maybe you can supply a video?

As for agahnim hijacking you into dark world:
Avoid this by:
pc 00/7983: 40 -> 00 to tell the game you're in light world
pc 01/5E2E: 5b -> 1b screen number.
pc 01/1e4c:09 -> 02 plays overworld theme instead of dark world theme but your table music has priority

It is not yet bug free as far I see. So far I can tell it works only bug free if you use 1b (castle), in others you can't move or there are graphical glitches. But test it out yourself. 1B however is modern world, but I think for your game progress it might be coolest if Aghanim sends you straight into waste lands, and you encounter this world this way the first time. 8)
You can test pc 01/5E2E with your favorised transport screens and look whether it works (as it does in ALTTP with 1B). If not I'll check the code again.

Edit:
Ok, already checked:
It is the following

$00/F964 BF 39 F9 00 LDA $00F939,x[$00:F93C]
$00/F968 85 A0       STA $A0    [$00:00A0]  

So when aghanim transports you this address (pc: 00/793c) is 20
You seem to make it only the way that you come out of a cave if you want to be warped in an area other than 1b (also 1b you exit the door of hyrule castle, therefore 20 works).
If you e.g. want to be warped in Lost woods
you need
pc 01/5E2E: 2b -> 00
AND
pc  00/793c: 20 -> e1 (so you leave at thieves hideout)
I can trace this number to store at 7e/00a0 as soon I know where you want to end (but must be an exit). Unfortunately, it seems like changing this will also delete the message sahrasladingsda gives you when getting into dark world

Conn wrote::affraid: 
oh well... I guess somebody has to write a program to convert these midis into a file that can be included in HM. It may be doable by hand... but
Read this tutorial how you may achieve... I think we need Potentialing here

http://zeldix.forumotion.com/t154-the-music-tinkering-thread#1295

I've check out your tutorial and will await the final version of it, so far so good, there's nothing out there that seems too hard to do!

Conn wrote:I received your rom... I was not able to hear a fog sfx in area 00 and couldn't trace a sfx (usually written to $2141, $2142, $2143). Maybe you can supply a video?

Nah just forget about it, it's a barely noticeable sound anyway (for exemple you never noticed it ) it's more me nitpicking all the wrong smaller issues lol

Conn wrote:As for agahnim hijacking you into dark world:
Avoid this by:
pc 00/7983: 40 -> 00 to tell the game you're in light world
pc 01/5E2E: 5b -> 1b screen number.
pc 01/1e4c:09 -> 02 plays overworld theme instead of dark world theme but your table music has priority

It is not yet bug free as far I see. So far I can tell it works only bug free if you use 1b (castle), in others you can't move or there are graphical glitches. But test it out yourself. 1B however is modern world, but I think for your game progress it might be coolest if Aghanim sends you straight into waste lands, and you encounter this world this way the first time. 8)
You can test pc 01/5E2E with your favorised transport screens and look whether it works (as it does in ALTTP with 1B). If not I'll check the code again.

Edit:
Ok, already checked:
It is the following

$00/F964 BF 39 F9 00 LDA $00F939,x[$00:F93C]
$00/F968 85 A0       STA $A0    [$00:00A0]  

So when aghanim transports you this address (pc: 00/793c) is 20
You seem to make it only the way that you come out of a cave if you want to be warped in an area other than 1b (also 1b you exit the door of hyrule castle, therefore 20 works).
If you e.g. want to be warped in Lost woods
you need
pc 01/5E2E: 2b -> 00
AND
pc  00/793c: 20 -> e1 (so you leave at thieves hideout)
I can trace this number to store at 7e/00a0 as soon I know where you want to end (but must be an exit). Unfortunately, it seems like changing this will also delete the message sahrasladingsda gives you when getting into dark world

Thanks for this *must have info*, I'll work something out! Teleporting straight into the wastelands wouldn't match since you'll already have visited that world by the time that you defeat agahnim the first time (draegor 1). The next dungeon after that is located in the rift and is the Spencer Estate.

ah yeah, there's also the problem that if you die on any overworld you start over at the 02 cave again. So if he teleports you anywhere you must get access there from the normal start as well (in ALTTP) you also have already the mirror, so that he takes you to the dark world has actually little effect.

uhoh, these are the values for the first battle... thought you'd need them that he doesn't take you in the dw, and not the values for the second?! In the second fight you need the hole of the bat at another place I think, right?
In any case, if you know which screen and entrance he shall teleport you, let me know.
(maybe in both battles, guess the code is the same more or less).

This is why Parallel Worlds and also GoW (and GoT) all avoid the second fight all together, since the second fight triggers the entire event, making a hole and later the overlay etc. All in dark world, all related to the area 5B, which has a hardcoded backdrop (sunset ovelay).

Conn wrote:ah yeah, there's also the problem that if you die on any overworld you start over at the 02 cave again. So if he teleports you anywhere you must get access there from the normal start as well (in ALTTP) you also have already the mirror, so that he takes you to the dark world has actually little effect.

since there's no dark world in this game it's not a problem, and every part of the rift outdoor area (those four screens in the middle of the world), will be made so that each item you get allows you to easily go back to the other worlds.

Conn wrote:uhoh, these are the values for the first battle... thought you'd need them that he doesn't take you in the dw, and not the values for the second?! In the second fight you need the hole of the bat at another place I think, right?
In any case, if you know which screen and entrance he shall teleport you, let me know.
(maybe in both battles, guess the code is the same more or less).

after the first fight he teleports you next to the exit 0020 (not hardcoded, can be anywhere you want):




after the 2nd fight he teleports you right next to the Fly-9 location in HM. can be any screen, it'll load the overlay which you drawn in the 32x32 block editor (blocks 3647-3655). When you switch screens however the overlay disapears (that overlay is hardcoded in overworld area 5b).



I haven't decided yet the exact place where I'll teleport Link in both times, but when I'll do, I'll be sure to tell ya!

*rings a bell

codes for first transport:
pc 00/7983: 40 -> 00 ; must be 00 to tell the game you're in light world
pc 01/5E2E: 5b -> xx ;your desired screen number
pc 00/793c: 20 -> xx ;your desired entrance number in that screen

and I checked it. If I set 01/5e2e to 00 (lost woods), and 00/793c to E1 (entrance e1 in area 00), I got to the thieves hideout without bugs. So here you can help yourself where Aghanim shall put you!


btw; pc 01/1e4c:09 -> 02 plays overworld theme
is not needed! The music table I coded has priority... so the theme there will be loaded in any case, equally how you set this value.

So with the three addresses for the first transport (light world, screen number and entrance number) you can help yourself with everything... what do you need after the 2nd battle and what do you already know (no dark world, bat cave at another place, flute transport to another place)?

Amazing this pretty much solves all the problems with the first fight with agahnim! Hyrule Magic writes in dungeons in decimal, knowing this hex number 20 refers to room 32 for the first fight

About the second fight. Pretty much what you said.

about that third point: the flute transport is done in hyrule magic. when your eight flute transport nods are set in the areas of your choosing, you can add a ninth transport fly nod anywhere you want, that's that event!

Here's a good video of the whole process:



You basically need to have the correct tilesets to load in both that dungeon boss room and that overworld area for the full effect. In the four tilesets for both the dungeon room and the area, it uses the second one. In hyrule magic, first tiime you fight agahnim is room 32 and second fight in room 13!

ok so you need me to make the overworld only (batcave somewhere in the overworld)...

As for the 3 codes for Aghanim transports you the first time:
pc 00/7983: 40 -> 00 ; must be 00 to tell the game you're in light world
pc 01/5E2E: 5b -> xx ;your desired screen number
pc 00/793c: 20 -> xx ;your desired entrance number in that screen

here's also a 4th:
pc 00/796b: 20 -> xx; your desired entrance number
if you set this value to the new entrance number as well, you'll hear also the wind blowing and sahrasdingsbums message to rescue the maidens. I'm sure you'll need that effect and text also in your new hack.

and a fifth:
pc 01/01AC: 20 -> xx; your desired entrance number.
If you saved and start over in the dark world, the game puts you to entrance 20 of your exchanged screen. If this entrance is not set as well the game tries to put you on the pyramid and thus crash! I do not know whether it is relevant for your game since you cannot start over in darkworld since there is none, but in normal ALTTP it is absolutely necessary to change this as well.


----------------------------------------------------------------------------------------
2nd transport:

(1) change:
01/6AF5: 5b -> xx ; your desired screen number

(2) change:
01/46d1: af ca f3 7e 29 40 f0 02 -> a9 00 8f ca f3 7e 80 02
This is necessary to not get into dark world, (hardcode to save that you're in light world). Maybe not necessary in ~your rom~ since you should be in light world when encountering Agahnim #2.

(3) change:
set new warp point fly--9 into new desired screen (not necessary since Link seems to always follow Ganon

Problems & bugs:
(1) Then the difficult part starts: the bat gfx gets messed up, as well as the hole (dark world sprite only?)

(2) Further, it works only in gigantic areas (pyramids 5b, castle 1b, kakariko 18, lost woods 00). Do you have such a big area in your rom? Right now I do not know how to set it to small areas... and I already traced me nearly to death to find this out
If you set e.g. screen 2c (start, small) to where the bat flows, the coordinates handle it as it were a big screen, so the first part of the cave will be stored to top right of screen 2b, the second to the top left of screen 2c. You therefore need to shift the coordinates.


----------------------------------------------------
Edit: found how the coordinates are set to get coordinates also for small areas: (the bat caves has 3 rows and 3 tiles each row) = 9 tiles
first row (2 coordinates, first handles 1 tile, second 2 tiles):
0D/C2Aa: bc 03 -> be 03 (shift one 16x16 to right); -> ba 03 (shift one 16x16 tile to the left)
0D/C2B4: be 03 -> c0 03 (shift one to right)

second row (one coordinate for all 3 tiles):
0DC2c0: 3c 04 -> 3e 04 (shift one to right)

Third row (one coordinate 1 coordinate for all 3 tiles):
0dc2cc: bc 04 -> be 04 (shift one to right)

So you can place the bat hole to any location add or substract 2 to the first byte to shift to place the batcave (each 2 bytes = 1 16x16 tile). If you have the coordinates set the 7b for the cave entrance onto that hole via HM.
If you have problems; I'd need the exact location where you want it to place it correctly then.

------------------------------------------
To stabilize the cave (leave, reenter the screen), it is a bit more complicated. Here all 9 cave tiles needs to be addressed manually

07/7aD3 BC 23 -> be 23 (shifts one tile to right; ba 23 shifts one tile to left)    
07/7aD7 BE 23 -> c0 23 (shifts one to right)
07/7aDb C0 23 -> c2 23 (shifts one to right)
07/7aDf 3C 24 -> 3e 24 (shifts one to right)
07/7aE3 3E 24  -> 40 24 (shifts one to right)
07/7aE7 40 24  ->  42 24 (shifts one to right)
07/7aEb BC 24  -> be 24 (shifts one to right)
07/7aEf BE 24   -> c0 24 (shifts one to right)
07/7aF3 C0 24   -> c2 24 (shifts one to right)

(Note, in case you exceed the number, e.g., fe 23, the next would be 00 24)

Then you need your screen number, double it and add it to 07/7664. At the resulting address you must write cf fa.
E.g. you want the bat cave in screen 2c (start). Double of 2c is 58
07/7664+58 = 07/76bc
at 07/76bc you find 2d f8. You must write instead cf fa.

It is possible that the batcave will also be established in 5b in your rom. Since you don't have it, it is set maybe as layer of 1b. We have to look. If it is the case we need to disable
07/7664 + b6 (2x5b) = 07/76CF somehow (by exchanging the cf fa there to another value).

Complicated...? Well you want this patch

To center it it is best to add (or substract 20 bytes), so
07/7aD3 BC 23 -> dc 23 (centers in 2c) or 9c 23 (centers in 2b)    
07/7aD7 BE 23 -> de 23 (centers in 2c)

One further point: to make the stabilized cave work, you need to set
7e/f280 + screen number to value 60.
In native 5b screen it is 7e/f280+5b=7ef2db
for screen 2c it would be 7ef280+2c=7ef2ac
so write at
pc 0d/c2e5: af db f2 7e 09 20 8f db f27e --> a9 60 8f ac f2 7e ea ea ea ea

Edit:
Getting even more complicated... while I got the cave at the right place, the bat sprite vanished.
Further, though the tiles are correctly written at the correct place in 7E/2000,x the vram transfer of the tiles is missing when leaving and re-entering the screen. There a further dma transfer of the tiles needs to be implemented.
This is not for the bat follow (here the cave is placed correctly) but to stabilize the cave when leaving the screen.

Here's what I got as progress:


Seph, this is getting really complicated. Maybe it's better to continue as soon you know for sure where you want to locate the batcave. Further, I dunno whether Euclids or Math's hacking skills could be better suited for this task.