possible romhack: dodonpachi without music?

[brook4]

I've been grinding dodonpachi lots and it's nice to listen to different music but I really miss the explosion sound effects, so I was wondering about turning off the music. MAME has two volume sliders but they affect left and right channels, not music vs sfx channels.I did some digging:

The game runs on CAVE 68000 Hardware and uses the ymz280b chip for sound. I was looking at the MAME source code for the cave driver and ymz280b and it seems what happens is that it loads the files u6.bin and u7.bin from the dodonpachi ROM into the memory of the sound chip.

So I tried corrupting those two files with random data and it does change the sounds in the game to random noise without breaking anything else - but I have no idea what format those files have in order to just zero out the music. Any ideas how?

[PC Engine Fan X!]

As it is, it's a classic danmaku STG title worth listening to with the original BGMs in place -- this applies to the DDP PCB version, of course.

I wouldn't change anything about the classic audio-visual masterpiece that is the DDP PCB...the definitive version to play/own.

Sure, I've played the PCB version with the volume turned off & it's akin to playing an STG missing a key component, the audio portion which really gets the blood pumping/not to mention sharpening the usual hand/eye coordination reflexes.

PC Engine Fan X! ^_~

[BareKnuckleRoo]

It's only got 3 stage tracks. They're not bad, but they get old quicker than games with each stage with a separate track.

I'm doing some messing around with this by replacing u6.bin and u7.bin with zero-byte versions. So far nothing broke seriously except for clicking where it seems to expect sfx. They don't seem to be divided between one for sound one for music - zeroing one or the other only just results in half the game's sounds missing, music playing badly, etc. trap15 would probably know better how feasible it would be to add a 'no music' toggle in the game options that disables music entirely.

[KAI]

A game without music is like a pizza without cheese.

[Thorham]

As it is, it's a classic danmaku STG title worth listening to with the original BGMs in place -- this applies to the DDP PCB version, of course.

I wouldn't change anything about the classic audio-visual masterpiece that is the DDP PCB...the definitive version to play/own.

This thread isn't about you and what you like, but about what the OP wants

[antron]

Maybe replace the audio tracks on one of the ports. Would certainly work on the Saturn one.

[Despatche]

i have wanted this forever. every game should have the ability to turn off music and sfx, and to adjust their volume, however you desire. ddp with its incomplete soundtrack is something of a sinner, and needs to be brought to justice, etc.

[DJ Incompetent]

i have wanted this forever. every game should have the ability to turn off music and sfx, and to adjust their volume, however you desire. ddp with its incomplete soundtrack is something of a sinner, and needs to be brought to justice, etc.

C'MON TRAP15! WE GOTTA BELIEEEEEVE!!
kekekekekeke

This thread isn't about you and what you like, but about what the OP wants

PCEFX's opinion is always important. All the time.

[VixyNyan]

Maybe replace the audio tracks on one of the ports. Would certainly work on the Saturn one.

Yes and also, turning off XA streamed audio (which I think the PS1 port is using) on a PS1 emulator seems to work too.

[Ed Oscuro]

PCEFX's opinion is always important. All the time.

PC Engine Fan X! doesn't have opinions, only knowledge.

[brook4]

i have wanted this forever. every game should have the ability to turn off music and sfx, and to adjust their volume, however you desire. ddp with its incomplete soundtrack is something of a sinner, and needs to be brought to justice, etc.

I really think that it shouldn't be too hard, It seems like it's just a matter of working out which regions of the ROM to set to zero because (I'm guessing) they just hold an index that tells the game which sound clips are where, and then at those locations there would be the coin sound, shooting sound, laser, bomb, and various music riffs.

I've been looking hard at the source code in MAME for the sound chip though and it just doessn't make sense. I also searched around for video game music/sound extractors in case that would help find out about the rom format but no luck with that. I'll try looking at it again I guess, no other ideas.

[Keade]

I am really no expert, but trying to entirely disable one channel (the one used to play the music) sounds more simple to me.

For instance, in ymz280b.c I see that loop (l 458)

/* loop over voices */
for (v = 0; v < 8; v++)

You might be able to mute a channel by messing (MESSing ?) with that loop and its underlying code.


About figuring out what the sound chip is actually doing: have you tried MAME/MESS debugger ? (I am really not sure it can be as useful as with CPUs, but it can't hurt to try)

[brook4]

I am really no expert, but trying to entirely disable one channel (the one used to play the music) sounds more simple to me.

For instance, in ymz280b.c I see that loop (l 458)

/* loop over voices */
for (v = 0; v < 8; v++)

You might be able to mute a channel by messing (MESSing ?) with that loop and its underlying code.


About figuring out what the sound chip is actually doing: have you tried MAME/MESS debugger ? (I am really not sure it can be as useful as with CPUs, but it can't hurt to try)

That's a fantastic idea!

I just put if(v == 0) continue; in there and I think that my copy of MAME has all the sound effects and no music (only tested on stage1 though). Thanks a lot

[Keade]

Happy it seems to work, I wouldn't have bet even a penny on such an ugly hack (to start with, there was no guarantee the game always use the same voice for music playback from one stage to another, or even during the same stage)