Is it possible to vga patch a GDI dump?

I know its possible with cdi searching for the JUE string. Is there something similar for a raw gdi?

 

Convert the GDI data tracks from bin to iso using the tools in the ISO Make Pack available on the DreamShell downloads page (http://www.dc-swat.ru/page/dreamshell/)

Then follow the exact same steps you would for a CDI, on the track03.iso file.

 

"The exact same steps you would for a CDI" means writing "1" (aka 0x31 aka 8-bit 49) in track03.iso to offset 61. You can then convert back the iso to bin, or modify the gdi file to use a track03.iso file in 2048 bytes/sector mode.

You could also simply open the bin with any hex editor, edit the 61th+16 = 77th byte to character "1" (should have been "0" prior), then use the program magiciso to rebuild the sector EDC/ECC (NOT correct it).

 

I'm unable to open track3 bin in magiciso. It gives me a "Found an invalid directory in the iso file" I've tried multiple games. Any ideas?

Or how do you do convert the iso back to bin?

 

Why bother converting back to bin?

When we (that is, Dumpcast and TOSEC) set the dumping standards for Dreamcast GD-ROM images, we suspected that there were GD-ROMs that had copy protection based upon error correction modifications. That has not been the case, so unfortunately distributing GD-ROMs as 2352-byte sector raw dumps has been kind of a waste (although it has had its advantages in some areas).

If you used the Optimize GDI script in the ISO Make pack, it will convert your .bin files to .iso as well as change the lines in the .gdi file to specify 2048 bytes per sector instead of 2352. There should be no need to convert back.

 

thanks darcagn. That worked perfectly!

 

I didn't know that the tool you referred to was actually editing the gdi to use 2048 bytes/sector data tracks. Of course then simply using that tool is a better idea.