how do i edit the title screen in bugs bunny crazy castle for nes

Started by ValisEmma, May 08, 2023, 10:30:06 PM

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i inserted the graphics but i dont know how to re arrange the tiles, do you know what address the title screen data is on?


Tile arrangements as you term it is generally known as tile mapping if you look in hardware documents, maps being what you will hear the sections of data that do the deed. Not to be confused with mappers though which in the electrical sense do a similar job but in this case deals with the cartridges instead (granted that also plays a role in some graphics aspects in some games). Granted just to be fun pattern tables is also a term of choice and all of it falls under the PPU.

If you can then stick within original parameters but it is not always possible (if nothing else repeated tiles can be a thing to save space in memory).

I checked the wiki here and there does not appear to be an entry for this game on this system (I think most look more at the gameboy versions).

You would then get to find your own. People have got lucky before by grabbing the relevant data from the running ROM and searching the ROM for it (i.e. the data in the relevant part of RAM handling tile mapping is copied directly from the ROM without any changes as opposed to changed or generated by code) but I would not count on it. To that end you are going to be thrust into the world of debugging possibly earlier than you might like to (if you are asking this sort of question then... people have done worse but it is not ideal).
To that end you would set up to watch the parts of the PPU in question before the screen gets drawn (title screens are good here as opposed to end screen for a hard hidden challenge) and watch (probably by means of a break on write breakpoint being set on said parts of the PPU) as the hardware builds it up, hopefully it being data from the ROM you can then edit rather than code but either way you would have your path forward. I am in a bit of a rush so can't describe debugging in terribly great detail today but plenty of others have.


In the hack of The Bugs Bunny Crazy Castle called The Bugs Bunny Crazier Castle, the readme file has contains lots of hacking notes and includes a section about the title screen. In the Readme File, scroll down or find the section that starts with "Title screen nametable at 8597".

Also, here are some spots in Cyneprepou4uk's disassembly of the game that look relevant, but I haven't examined this code in detail:
bank_02.asm, sub_8587_draw_title_screen:
bank_FF.asm, sub_ED5F_draw_screen_handler:

(I assisted on that hack examining some other bits of code, but the design and graphics modding was done by Garrett Gilchrist (tygerbug). I remembered he changed the title screen, and when I looked over the readme file I saw that information about the title screen.)

Quote from: FAST6191 on May 11, 2023, 12:03:46 PMI checked the wiki here and there does not appear to be an entry for this game on this system

There is a page about the game in the wiki Data Crystal: The Bugs Bunny Crazy Castle. It doesn't have a ROM map or RAM map or infomation about the title screen, but some of the other links and info might be helpful. (I added the Notes page about the stage numbers and password format.)


My bad, scanned the page but the "the" caught me out. Nice to know there are some notes as well. Missed there was a disassembly going on as well.


  Yes, I hacked The Bugs Bunny Crazier Castle, with help from Bavi_H and SpiderDave (both of whom did the more technical and complicated stuff), and Cyneprepou4uk's disassembly. There are many unusual aspects to the title screen which have to be worked around! Hopefully the Readme explains it somewhat.

The cutscenes use a rudimentary RLE compression.

 FF xx yy  Output tile xx yy times.
 00-FE     Copy input to output.
 FF FF 00  End of data.  The second byte can be anything, but FF is used.

    We tried to add the ACME Factory ending from the FDS version, but didn't quite finish it - the version here isn't animated.

    I also wanted to add the two unused cutscenes back to The Bugs Bunny Birthday Blowout but never figured that out.