QUOTE(CaptainM @ Jun 26 2007, 05:30 AM)

Hmm... I when it comes into the "grey area". I have a softmodded xbox, so I don't think I can load a different bios. It sounds to me like arcade emulation is extremely tricky. Personally, I just wanted to play a few rounds of Metal Slug, but it may not be worth it. I am going to assume this is why surreal64 won't work either. I have not audited any roms. I really appreciate your help. I am going to try a cps2 rom I have tomorrow to see if it works. Just a quick question, if I have a softmodded xbox, does it use a bios? I read some number ending in 930 somewhere and I think I remember a bios or kernal version in front of it. Is that the MS bios?
Ok, the mod you're running, be it soft mod, TSOP flash, mod chip, etc has no bearing on the NeoGeo BIOS. The NeoGeo BIOS is a file called 'neogeo.zip' which the emulator uses, if you don't have a file with that name in your ROMs folder, no NeoGeo games will run at all, ever. CPS1&2 games aswell as the "other" games can still run without this however.
The neogeo.zip file like proper games also has multiple files inside it, and these need to be correct, not any downloaded neogeo.zip file work.
Auditing ROMs can be scary at first, but I recommend ROMcenter. First you need to run FBAxxx and in the options choose generate DATs. This should generate two .DAT files in your FBAxxx folder, transfer these to your computer then from inside ROMcenter you load one (it will be called ROMcenter.DAT), and this is what is used to check if your ROMs are correct, including your neogeo.zip (BIOS file).
Just so you know, when I generated my .DAT files, FBAxxx crashed, but the .DATs were still in the FBAxxx folder and fine, so don't worry if the same happens to you.
I forgot to mention, the generated .DATs only provide information on the ROMs FBAxxx expects, not the ROMs on your Xbox, you have to have a copy of your ROMs on your PC to check them to see if they are correct.
Even if you're not sure of what to do after checking your ROMs, at the very least you will know which games you have that (should) work and which ones don't and you can see if your NeoGeo BIOS is correct too.
Alternatively, you could try to find a download of FBAxxx with all the ROMs, although linking to such a thing is against the rules, and I also don't know where to get that, I'm sure it must exist though.
Hope this spiel helps.
edit: damn typos.