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Logging from Genesis ports of Spatter and Super Locomotive

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Logging from Genesis ports of Spatter and Super Locomotive

Post by SeregaWin555 »

Hello! I tried logging from Genesis ports of Spatter and Super Locomotive, patched to run on common emulators, but when I open any logged VGM from these games, some notes are missing. Possibly, YM2612 instruments that "emulate" the second SN76489 from arcade versions don't seem to be recognized in any VGM player.

Here are VGMs that I tried to log for reference
Attachments
blastem_20230717_193636.vgm
(663.57 KiB) Downloaded 32 times
blastem_20230717_193554.vgm
(44.45 KiB) Downloaded 32 times
Last edited by SeregaWin555 on 2023-07-18, 2:33:50, edited 1 time in total.
  • andlabs Offline
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  • Joined: 2011-12-04, 22:00:12

Post by andlabs »

(Please don't post the ROMs here; thanks)

Post by SeregaWin555 »

andlabs wrote:(Please don't post the ROMs here; thanks)
OK, I'll know. I'm new to this forum
  • andlabs Offline
  • Posts: 185
  • Joined: 2011-12-04, 22:00:12

Post by andlabs »

So what's going on with these games is that they're using the YM2612 to simulate the dual SN76489 setup of the original arcade games (rather than having an arranged FM soundtrack). The SN76489 has no concept of "note on" — the oscillators are always running at the volumes they're currently set to. These games do the same thing: they trigger the YM2612 "note on" at the start of the game and then just change the channel volumes as needed.

Unfortunately, this means that your VGMs are missing that initial "note on", which is why the channels are silent. And since blastem isn't logging those, and vgmtools doesn't have a fix for that, manually modifying the VGM files is necessary to fix them.



That being said, I'm extremely hesitant to accept Mega Drive Mini 2 packs right now. With the Mega Drive Mini 1, the two new games (Darius and the re-made Tetris) were immediately posted online, and since they're just standard Mega Drive ROMs with no extra hardware or manual checks, they could be run on any emulator or even on the original hardware. Sega and M2 very much did not like this, hence the odd manual patches to these new ROMs this time. And while (as you know) this can be worked around for now, we'd rather not have them go further next time, so ROM pack maintainers and enthusiasts are trying to *not* spread the ROMs (patched or otherwise) widely now. I'm going to extend that to VGM rips for the same reason. If things change (I'll use MAME and no-intro as a barometer for change) then I could change my mind, but it's very much not likely to happen any time soon, sorry.

(There is some additional concern about hosting recently-released games *in general* but that's a decision that we'll make separately and more formally.)

Post by SeregaWin555 »

However, with logging VGMs from Star Mobile MD version, Fantasy Zone MD port and Devi & Pii no problems were detected: all used channels are not silent
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