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Author Topic: NES Background Editing  (Read 525 times)

venixuc

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NES Background Editing
« on: September 21, 2020, 11:03:45 pm »
I'd like to know if background from one nes rom can be imported into another. More precisely, would it be possible to replace Super Blaster VII Turbo 28 (http://www.mediafire.com/file/d26793n1671jaqb/Super_Blaster_VII_Turbo_28_%2528Unl%2529_%255B%2521%255D.nes/file) stages with Street Fighter VI 12 P (https://www.emulatorgames.net/roms/nintendo/street-fighter-vi-12-peoples/) stages? I also noticed that dojo stages from the latter rom are based on Scene 6 from TMNT 2: The Arcade Game. Which tools I would need for this? And, would it be possible to use portions of TMNT 2 Scene 6 level to further edit original dojo level? Thanks.

nesrocks

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Re: NES Background Editing
« Reply #1 on: September 22, 2020, 10:54:27 am »
It can be done, but it requires a good understanding of nes assembly language and debugging tools. You're gonna have to reverse engineer the compression format, compress the new background tiles into that format and insert that into the game.

In theory you can write your own uncompressed nametable writing algorythm into the correct section of the game's code, but you're going to run into trouble finding rom space to do it. Unless you're really lucky and this game stores every background already uncompressed, then it would be the easiest scenario, but that's almost guaranteed to not be the case.

venixuc

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Re: NES Background Editing
« Reply #2 on: September 22, 2020, 06:20:39 pm »
Thanks for your reply.

I thought it would be easier as both games are developed by the same company, work basically in the same way and the code is probably similar (2 Street Fighter roms, not TMNT 2).
And, one question for everyone: Do you think that this is worth trying or is it simply way too overambitious idea that would require colossal amount of time?