Adding Custom Title Intro NES Rom

[Kazufox]

I'm still a bit new to working on ROM Hacking and have some understanding with Hex editors to change things up. But I don't know how to add something external into the game like an intro graphic before the title screen starts up.

I should mention, I've got the graphic I want already made into a .chr, .rle, and .pal files based on the tutorial here: https://cppchriscpp.github.io/nes-starter-kit//guide/section_4/title_screen.html

I just don't have any clue about working the actual coding parts.

[Psyklax]

Depending on the ROM, you might have trouble squeezing something like that in. NES games aren't known for their massive amounts of free space.

That tutorial seems to be aimed at people making their own games, rather than people hacking existing games. I wouldn't think that doing something like this is very common amongst ROM hackers, for obvious reasons.

[Kazufox]

I had a feeling that was the case, I know the NES games were very limited in what they were able to do and weren't exactly optimized the best. I figured it was at least worth a try anyways. And for right now, it's for an SMB3 ROM I planned on trying it on.

[KingMike]

Especially with CHR-ROM games, you're going to have a hard time fitting in custom graphics unless there happens to be a CHR-ROM bank with a lot of empty space you can use for the new graphics.
(CHR-ROM means the tileset is used directly from the ROM, the entirety of one or more entire ROM banks with no user control over which individual graphics get loaded.
CHR-RAM means the graphics are loaded from the game programming, allowing the user control over graphics, but as mentioned, you're not likely to find a lot of free space in the PRG (program) ROM to store custom graphics plus the code needed to display a screen with them.)