How to edit game states (SAVE-S) of the SEGA Dreamcast
Thanks to the Internet DC capability (.VMI + .VMS files), or e.g. an SD card reader, Nexus card (DCI files) or the Dreamexplorer program, we can now edit the Dreamcast's game states. How to do it and what can we get from it? I will try to describe it to you.
Let's start with the fact that by editing the state of the game, we can also change the regions (PAL, NTSC-U, NTSC-J), thanks to which we will be able to play any systemic game using a saved game.
I take Tokyo Xtreme Racer 2 as an example (in Tokyo Highway Challenge 2 and in Japan Shutokou Battle 2) and change many game elements such as the amount of available cash in a given title, names and more. I leave the hacking fun to you.
Once we know what pair of saves we want to edit (it's best to do it on the .vms file, because .dci complicates the editing a bit and the .vmi file is the only file with the information needed by the console), it's time to run any hex editor and open said file. In the comparative photos (No. 1 and No. 2) I marked the line (it is usually the 4th and 5th line, which is responsible for the so-called "region protection". The selection below should be changed, copied to the selected state of the game or entered identical values.
If you want to edit other data (I took car brands as an example), find the values you are interested in in Ascii (normal - readable) mode and convert them (see fig. 3). They can be whole names, numbers and abbreviations.
After editing, it's time to verify the checksums (CRC) and create a new .VMI file.
For this we will use the Vmu Writer program. Select the .vms file with the Open option, then enter any text or description in the Description (Fig. A) and Copyright (Fig. C) fields. The Resource (fig. B), Vms file size (fig. E) and Type (fig. F) fields should be left intact. Instead of Vm File Name (Fig. D), enter the same name as in the source game (the one from which we copied the region). Always pay attention to this name, because sometimes (e.g. in additional saves like PSO quests etc.) they differ only in the last three characters and it is enough to change them. In some cases, although the bonus save is from a different region, it fits every version (eg Addons from Shotokou Battle 1) and does not require any changes. To find the source data just open the original .vmi file (picture below) with the same program.
Then save the newly created .vmi file with the save option. The last step is to fix the checksums. You can perform this operation with the VmuExplorer program (available in the downloads section), by selecting the - Fix File's CRC option from the Edit menu.
The operation is now complete. Just import the save to our VMU (via Dreamshell or burn it to a CD and use Dreamexplorer) and enjoy the fruits of your own work (or hack). For training, I advise you to use one of the DC emulators for PC.
PS. Editing of this type is also possible directly on Dreamcast, in Dreamexplorer, but it takes much longer and requires more work.
