Unibios ADPCM-B Channel Swap Possible?

[Neo Alec]

Is it possible to add a toggle to the Unibios options to swap the left and right channels for ADPCM-B? I assume not, since the bios doesn't communicate directly with the YM2610.

 

[tcdev]

I don't see how it could, no.

 

[Neo Alec]

Had to ask anyway.

Individual hacks for each game then? How about a toggle in the NeoSD menu?

 

[tcdev]

Had to ask anyway.

Individual hacks for each game then? How about a toggle in the NeoSD menu?

Not sure any (program) hack would be possible, even per-game. The ADPCM left and right channel values are interleaved, and the hardware itself reads it from memory based on start/end addresses (with 256-byte granularity) programmed into the registers. There's no data path between the VROM and the YM2610 that can be manipulated by the Z80.

You could swap the channels in the VROM data if you know where the ADPCMB data is?!? What are you trying to achieve and why?

 

[Neo Alec]

What are you trying to achieve and why?

Heh. It may be obvious for many reading this. Bitmap Bureau disovered a previously undocumented bug in NEO-YSA2 last year: The ADPCM-B channels are swapped!

I know it's a very minor thing, but I wondered if an easy fix could be implemented for folks using a stereo modded MV-1C board like myself. A toggle to correct it in the bios would be ideal.

Artemio's new 240p Test Suite does have a fix for this issue in the soft dips, but obviously that's a fix at the software level.