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converting ym2203 vgm to ym2612

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converting ym2203 vgm to ym2612

Post by nitrofurano »

i’m now seeing this:
how can we convert ym2203 vgm files to ym2612, and hear them on megadrive? (i’m specially curious about the arcade ones! ;) )
the video description also mentions vgm_opnatob , vgm_ayconv and vgm_opnclk , that i find nowhere - any clue?
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Post by l_oliveira »

A while ago I made those python scripts to experiment with that idea and the results were pretty damn encouraging.

What the script does is generate a hard coded header then copy all data over from source file into a new destination file. While doing so it scans and modifies the data to redirect writes meant to the second YM2203 into the second register array of the YM2608/YM2612. Also, it catches key on events meant to the second YM2203, redirecting and converting them to the first register array of the targeted FM chip.
YM2608/12 acknowledge key on events only on the first register array.

There's also other conversion scripts meant for achieving weird things like converting AY-3-8910 data meant for the YM2203 into a separate AY stream. That is meant for playing YM2203 data on a real YM2612 chip connected to a MSX computer (which has the AY-3-8910), achieving then playback on all channels.

Hope this is useful for you. I used this stuff to create the roms with the deadfish VGM player which plays Ghost'n Goblins music on the Mega Drive which were posted at SEGA-16.
Convert 2xYM2203 VGM to 1xYM2612
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Post by MaliceX »

Hi. I'm Marisueksu from YouTube. :P Thanks for your interest with that video.

Here's some links to what you're looking for. NOTE: No warranty implied. Use at own risk etc. - they're experimental at this stage.

vgm_opnclk you can find on this thread.
viewtopic.php?f=3&t=2013 for vgm_opnclk

....and i guess you found my other thread for the rest. :P

Post by nitrofurano »

thanks! \o/

Post by nitrofurano »

i tried on 07_NameEntry_unused.vgm (Tokio/ScrambleFormation, Taito - imho, Hisayoshi Ogura was a genius composing that with the resources and deadlines he had available that time - he mentioned a bit that experience at ) - the result differs on the notes frequency, more acute (i think it is related with a different frequency that the ym chip is running on each hardware - (~3MHz -> 7.67MHz, i guess) - i found similar situation from amstrad-cpc, ay-3-8910 runs faster there than on msx or zx-spectrum, and you can notice the difference instantly there as well) - is there some argument value we should add for reaching a closer result?
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