Tool to patch rom to external psg wanted

By st1mpy

Paladin (744)

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14-02-2021, 17:00

I made a external psg cart (same ports as megaflashroms psg 10, 11, 12). It works with joytracker, so its working.
I tried opfxsd with megaflashrom with /p or /p1 but I think it now conflicts with that psg so I get no sound.
Is there any tool to patch a rom for psg to external ports?

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By st1mpy

Paladin (744)

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14-02-2021, 22:34

OK, I never understood how to use sofarun in the past but just downloaded v8 to try the latest and now I managed to use it with my joypad. If I select megaflash rom ports as a choice for psg under the rom menu, the game launches with my psg cart (obviously without inserting megaflash rom to avoid conflict, not tried but didn't work with opfxsd so I didn't bother).

So, I can run roms. I wonder how to use mega roms, and would psg work? And how about dsk games...?

By Manuel

Ascended (17779)

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14-02-2021, 22:47

Did you try?

By st1mpy

Paladin (744)

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14-02-2021, 22:58

Slowly... tried dsk game, there is no menu option to choose psg port so that doesn't work.
Actually, now that I've read the manual little bit, I wonder if sofar detects my diy pac sram for game saves feature.

By st1mpy

Paladin (744)

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15-02-2021, 00:34

Got a mega rom to work (zanac ex), with megaram cart (512kb) through sofarun. And plays music on the external psg.
Couldn't get hydlide 3 to work.
(My super sd cart, megaram 512kb, musical memory mapper 1mb, diy ext psg, my super expander)

By st1mpy

Paladin (744)

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15-02-2021, 02:57

Tried a few games on the sofarun. Just noting the ones with issues.
Out of the normal roms, Warroid even after choosing mfr as psg, it just played sound from internal.
For megarom, dragon quest 1 again plays from internal. Dq2 works.

R-type and hydlide 3, just couldn't get them to run at all.

I think I'll just make the psg ports as the internal one, and make the psg write only (to avoid conflict with the real internal psg, my cart doesn't use sound in to msx, only external line out). That would make it work with most things, like vgmplay, rom and disk games etc

By sdsnatcher73

Paragon (1737)

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15-02-2021, 06:54

I think if you could move the PSG to the regular ports (maybe with a jumper) and have audio out (I guess you may already have) it would just work in harmony with the internal PSG, no need for patching anything. That is how Carnivore2 and Darky operate with their FPGA PSG / CPLD to ePSG. Basically all devices listening to the ports will receive the data, it will probably make sense to make these ports write only in such case.

By sdsnatcher73

Paragon (1737)

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15-02-2021, 06:58

And you could go a little crazy and put 2 YM2149’s on 1 cartridge, 1 on original ports write only and 1 on alternate ports for VGMPLAYand the rare game that supports dual PSG. (that would be on my wishlist Wink)

By st1mpy

Paladin (744)

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16-02-2021, 04:00

Thanks for your suggestions, I was thinking of jumper switches too, so I made one jumper for selecting internal or external version (GAL then uses the appropriate ports), and also another jumper to enable/disable read by msx (so making psg write only or not). Now I tested it as an internal port setting and works great, no patching games and vgm works as well. When I build some more I can insert 2 of these cartridges too.

By sdsnatcher73

Paragon (1737)

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16-02-2021, 08:07

Yes, great work! The benefit of having 2 PSGs in one cartridge is of course 1 less slot used Wink. With VGMPLAY supporting more and more chips slots are at a premium (and we don’t all have a Wavy3 with 3 external primary slots (I know there are a few other options but still 3 primary slots are rare)