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Author Topic: SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod  (Read 5043 times)

segwayspeedracer

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SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod
« on: October 20, 2018, 07:47:18 pm »
I have been using Mari0 and SMBx programs for some time because I love the idea of simultaneous multiplayer. Great news is that CorpseGrinder and Ti have produced the first ever simultaneous SMB mod.

I intend on building off of their work as a template for bringing my mario mods to have simultaneous multiplayer. The hack has most of the original information in the same order but in different locations. This post is to document the addresses where information is located, and to explore options for bringing in some new features into the game that most smb hacks have (reverse red piranha plants, for example).

Feel free to contribute - I find it useful documenting my notes online for my own benefit to pick up the project later if I need to temporarily suspend it.

x8e77 - Change Mario's starting lives. 02 is default (3 lives). 7F is max (128 lives).
x8053 - Change Luigi's starting lives. (credit to Corpsegrinder)
x844D - Change Mario's palette colors. In different order than normal.

x6182 - Change Luigi's palette assignment.

xF240 - Change Fiery Luigi's palette assignment

Luigi shares the palette with Green Enemies (normal) and Red Enemies (fiery)... so technically he will have different colors in every level type. Bowser's axe color will override any sprites that use the Green Koopa palette.. so far bowser's color is set to identical to the Green Koopa palette.

00 (same as Mario), 01 (Green Koopa), 02 (Red Koopa), 03 (Goomba) are the options. The number you pick is for normal Luigi. When Luigi becomes Fiery, it will add +1 to the palette. So if normal Luigi is pal 02, when he is fiery he will be pal 03. I think xF240 overwrites this.

xA471 - w1-l1 level data
« Last Edit: February 04, 2019, 11:32:36 am by segwayspeedracer »

NesDraug

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Re: SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod
« Reply #1 on: November 27, 2018, 06:25:17 am »
Great idea!

I have a big collection of my favorite SMB Hacks and it would be so awesome if one could patch all these hacks with the Two Player Hack. – I guess there's no easy way of doing that? Do I have to find that information in every single romhack?

I'm fairly (very) new to the romhacking scene, so bear with me.

- I just tried to patch some of the hacked roms with the "Super Mario Bros. (Two Players Hack).xdelta" patch file using MultiPatch. Naturally with no success since it needs the original rom.

- So I tried Lunar IPS. I made a new IPS using the original "Super Mario Bros. (W) [!].nes" and the patched "Super Mario Bros. (Two Players Hack).nes".
I then tried to patch my favorite romhacks with the newly created "Super Mario Bros. (Two Players Hack).ips" Still no success.


For example: If I would like to play "Extra Mario Bros." in co-op mode, what do I do?
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Jorpho

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Re: SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod
« Reply #2 on: November 27, 2018, 09:54:14 am »
- I just tried to patch some of the hacked roms with the "Super Mario Bros. (Two Players Hack).xdelta" patch file using MultiPatch. Naturally with no success since it needs the original rom.

- So I tried Lunar IPS. I made a new IPS using the original "Super Mario Bros. (W) [!].nes" and the patched "Super Mario Bros. (Two Players Hack).nes".
I then tried to patch my favorite romhacks with the newly created "Super Mario Bros. (Two Players Hack).ips" Still no success.
I suppose that might work with simple graphics hacks that don't change the ROM much, but Extra Mario Bros. is very heavily modified.

As suggested by the OP, you'd have to look at what changes the Two Player Hack makes to the ROM, and see if the same changes can still be made.
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segwayspeedracer

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Re: SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod
« Reply #3 on: December 25, 2018, 09:08:23 am »
Great idea!

I have a big collection of my favorite SMB Hacks and it would be so awesome if one could patch all these hacks with the Two Player Hack.

For example: If I would like to play "Extra Mario Bros." in co-op mode, what do I do?

Truth is... the best that I, or any general trial-and-error hacker, can do, is to learn exactly how the level and sprite data are arranged in the original SMB. Then, assuming that all of the raw level and sprite data in SMB2P Mod is exactly the same as the original SMB, simply put those changes in their new locations. For example, if the original walking Mario frame one sprite hex data is:

00, 01, 02, 03, 04, 05, 06, 07

then I would need to find where that string is in the SMB2p MOD using a hex editor.

If we wanted to mod 2p mods where we can simply have a rom with 2 patches, it would have to be a lot of legwork by the developers. I'm willing to bet my job that won't happen.

Sorry this post is in the morgue.... my job goes into huge upswings of activity and its hard for me to make time for this... I will make updates to the original post when I can. Please forgive if this is classified as an unnecessary bump.

Eden.GT

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Re: SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod
« Reply #4 on: January 05, 2019, 01:40:38 am »
Yeah, you'll definitely need to contact the authors of the hack instead of working on it alone. Especially if you don't have experience in 6502 ASM which will make the process tougher.
There's hope since this hack is rather recent and not ten years ago- Corpse Grinder has a Youtube channel so you might as well go ahead and ask him for the source code.
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segwayspeedracer

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Re: SMB 2p Co-op: TI - CorpseGrinder - Reverse Engineering Mod
« Reply #5 on: January 31, 2019, 09:00:11 pm »
This project will not be too difficult, because all of the general mario data, such as level arrangement, sprites arrangements are all the same. I am lacking in time more than anything.

More complex things such as how to change enemies palette assignments, or how to install the Lakitu Spiny horizontal momentum patch will require his support.