On 25 Apr 00, richard.munn@... (Richard Munn) wrote:

> Here's something interesting - A game which seems to do it's save CRC
> differently to the others - take a look:
>
> --- Paul Acevedo <eastman@...> wrote:

> > I'm trying to edit the save file for the Japanese game Space Griffon, but
> > have hit a big snag. I found where the variables are (for weapons, etc.)
> > but this game seems to use a different CRC method than other VMU files.
> > When I run VMS_CRC, I get this message:
> >
> > "Checksum-Field is zero. Really set new CRC value?"

Well, this means nothing but that the originally stored checksum value is
zero (usually an indicator that the file doesn't require a checksum).

> > Well, whether I set a new value or not, the game recognizes my files as
> > bad saves (with only 1 variable changed), so it seems to me that the
> > checksum field must be located somewhere else.
> >
> > Can someone PLEASE help me determine where that is and how to calculate
> > the new value? I can provide you with files to compare, etc.. Any help
> > would be appreciated!

I guess it's fairly easy for a game to create a checksum and then store it
within the saved gamefile at _any_ place desired, and upon loading the
saved game checking if it is valid. IMHO the only way to find out where
it is would be to compare two files in which only a single thing has been
changed (e.g. ammo decreased from 50 to 49) and then check what other
value(s) are different in the new saved gamefile.

Funny that no other Dreamcast games seem to have used this simple 'trick'
yet... ;)

Bye


Alessandro
---
You get what anyone gets. You get a lifetime.