> use this
> ucon64 -snes -mgd dirname
> these are the options used
> --snes force recognition
> --mgd convert to Multi Game*/MGD2/MGH/RAW
> this will both remove headers and convert to non-interleaved format
>
> however, this won't work in 100% of the cases,
> it fails in some bad/hacked roms
>

Thanks mameniac, this worked on almost all of them.