Player 2 Controller bug in ASMT...

[nanospark]

I know I'm a little late for finally bringing this to someone's attention, but I found a bug in the game that doesn't allow player 2 to spin jump with their own controller...however, player 1 can control player 2's spin jump (well...the A button in general).

I did a little research on SMWC, opened the ASMT ROM in my hex editor and found a little string of code in the area of the controller setting data that was different compared to a clean SMW ROM (x8C1-x8C5=5C A9 9C 3F EA instead of BD A8 0D 85 18...if that means anything to anyone). I copied the 5 byte long code from the clean ROM and pasted it over the changed area in the ASMT ROM and player 2 can now control their spin jump with their own controller.

I was wondering how to make an .ips file and who could take the file to upload the fix to SMWC (if they so please to do so)?

[yoshicookiezeus]

I did a little research on SMWC, opened the ASMT ROM in my hex editor and found a little string of code in the area of the controller setting data that was different compared to a clean SMW ROM (x8C1-x8C5=5C A9 9C 3F EA instead of BD A8 0D 85 18...if that means anything to anyone). I copied the 5 byte long code from the clean ROM and pasted it over the changed area in the ASMT ROM and player 2 can now control their spin jump with their own controller.

That wouldn't be the best of fixes, actually. What you overwrote is the JMP instruction for a hijack used for one of the patches, so restoring it would render said patch useless. The actual fix would be changing the byte at $308008 from AD to BD, since it would seem like chdata forgot a ,x when restoring the code from the hijack space.

Then again, given how the bug has gone unnoticed for five months after release and how the game is pretty much only meant to be played in single-player mode anyway, I am somewhat questioning the usefulness of uploading a bugfix.

Also moving this from the ASMT forum since that is only meant to be an archive for the original project threads.

[nanospark]

What you overwrote is the JMP instruction for a hijack used for one of the patches, so restoring it would render said patch useless.

What is the patch used for?

The actual fix would be changing the byte at $308008 from AD to BD, since it would seem like chdata forgot a ,x when restoring the code from the hijack space.

Are you talking about opening the ROM in my hex editor?...or something else? I went to that address in my hex editor and my screen is filled with nothing but zeros...

[Argumentable]

I think it would make for a nice duo LP though. One character controls the d-pad while the other controls ABXY. Only I guess this one only has A. It would still be amusing.

[nanospark]

Wow...I am an idiot! I just realized my modification ruined the checksum of the ROM (according to SNES9x)...(good thing I made a backup before I went messing about...the game still works)
yoshicookiezeus, I'm still lost on your method of fixing, though...

[yoshicookiezeus]

Oh right. The offset I posted was an SNES offset, as opposed to the PC ones used by hex editors.

[nanospark]

Oh right. The offset I posted was an SNES offset, as opposed to the PC ones used by hex editors.

How do I find the offset (I'm not exactly the greatest in this kind of stuff...)?

[yoshicookiezeus]

see: Lunar Address

[nanospark]

see: Lunar Address

Hmm...I went to the address that Lunar Address gave me from the offset that you gave me and my screen is still filled with zeros...what am I doing wrong???

[yoshicookiezeus]

Oh derp. Seems like I was looking at wrong versions of both the patch and the ROM; the proper offset should be $3F9CA9 (PC offset x1F9EA9).

[nanospark]

Oh derp. Seems like I was looking at wrong versions of both the patch and the ROM; the proper offset should be $3F9CA9 (PC offset x1F9EA9).

That one byte change fixed it (as opposed to my 5 which apparently ruined...something). I have a lot to learn on the structure of SMW...
I have one more question...what did the 5 bytes I modified actually do for the rom? I looked up in the patches section of SMWC for that instruction you were talking about (JMP) and found something called BoostROM. I know that there is a description for the patch, but it doesn't make sense to me...is this what they call ASM? (sorry if I sound really stupid at this point...I really am new to this sort of programming...all I have really done is look at each RAM address and do things in the game to see if the values change and see what each address does.)

(Oh...BTW...after I applied the fix you gave me, SNES9x still gives me a "bad checksum" message on the ROM start up)

[HuFlungDu]

(Oh...BTW...after I applied the fix you gave me, SNES9x still gives me a "bad checksum" message on the ROM start up)

Bad checksum means nothing. Just ignore it or open the game with LM and save.

[nanospark]

(Oh...BTW...after I applied the fix you gave me, SNES9x still gives me a "bad checksum" message on the ROM start up)

Bad checksum means nothing. Just ignore it or open the game with LM and save.

I'm going to go the ignore route because opening it up in Lunar Magic and saving screws up the music when going between rooms in some levels.