http://segahub.org/index.php?topic=6012.0
Obviously, every link in the post is dead, but the releaser had some interesting things to say in the .NFO. Obviously, this isn't Mercurius Pretty, which I also have an interest in, but it is an NEC Interchannel game, and uses the same DATA.IMG format, about which was said:
I've been searching for those scripts or that particular release. No joy. Perhaps one day.The Game is huge !!
The main protection here is a huge file DATA.IMG. It is simply a collection of
*.BIN, *.VTV and *.LTA. However, many of them are duplicated entries.
The FAT is encrypted. I have written scripts to decrypt and re-encrypt it. With
these scripts, I am able to extract the files and after cleaning up and
removing duplicates, the file reduces to 748M which nicely fit into a 95min CDR.
The game also checks the file size of DATA.IMG. To fix this protection, I have
modified the ISO File system with a fake file size.
I believe one of the file type is a variation of audio foramt. I have no
experience in audio formats but I believe that someone can down-sampled them
and make the game fit on 80min CDR.
I have included the scripts I used in case someone is interested in making a
80min release.