GNGeo Bios issues


Wax

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May 26, 2020
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I've been struggling with this for a bit now and I'm wondering if anyone here can help me out.

I have a working neogeo.zip, but GNGeo defaults to using the European bios, sp-s2.sp1. If I exclude that file, GNGeo fails to load roms. So I've been trying to rename other bioses to that and see if that works. It does, but the USA bios still has the censorship issues (grey blood in Metal Slug, for example) and I run into some very strange issues with the unibios. The biggest issue is that the select button no longer operates the coin switch, so I can't actually start games in MVS mode. I've tried every key on the keyboard, none of them insert a coin either. On top of that, with some roms (notably, the Metal Slug games), pressing Y (mapped to D on the NG) pauses the game and brings up what I assume is a cheat menu. There's no way to exit this once it comes up.

This has been pretty frustrating and confusing. I just want to play the arcade versions without censorship. Any suggestions?
 
As a follow up, this isn't an issue with NEO.Emu, but I don't think that emulator runs quite as well so it would be nice to get it working in GNGeo.
 
Normally, how would you choose the BIOS to use on GNGeo ?

Have you tried to put in neogeo.zip only the BIOS you want to use ?
If I understand correctly how it works, it searches the BIOS in the opened ROM folder... so you could create different ROM folders with their dedicated neogeo.zip... just a thing you could try.

I see that there's also a parameter to specify the region, and it is not used by the PND:
--country=... Set the contry to japan, asia, usa or europe

If you want to use that, you'll have to add it to the "runme.sh" in the PND, but added directly like that you will end up always with a fixed region, unless you make the script more dynamic first.

Maybe try the neogeo.zip with just the wanted BIOS trick first, to check it that works.

EDIT:

I'm not sure if this will work, but I see that there's also a configuration file saved in "./pandora/appdata/gngeo_pepone/conf/gngeorc".

You can try to add to it something like this:
Code:
country usa

Anyway, considering that I found no censorship issues, without any kind of customization, and using a neogeo.zip with all BIOSes, I suppose that maybe you are just lacking the right ROM+BIOS combination...

EDIT:

I see that in "Metal Slug 2", for example, there's a SWITCH to enable BLOOD, maybe yours defaults to OFF ?
Just load the game, press F3 -> "SETTING UP THE SOFT DIP" -> "SLOT1 METAL SLUG 2" -> "BLOOD" ON
 
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Thanks for this info, I'll give this all a try and see what's what. It would still be cool to know why the unibios behaves so strangely (I remember it being ok on my GP2X?) but the main thing is turning off the BS censorship.

Edit: The dip switch worked. Thanks! I didn't realize F3 did that. "Toggle test bit" doesn't seem like a good layman's explanation of that functionality.
 
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