I'm a retro gaming and media preservation enthusiast. i've been active on Nintendo and Japanese PC (Sharp X68000, FM Towns, PC98) forums for quite some time, and now i'm interested in dreamcast. I'm trained in Electrical Engineering and Math, but I dabble in programming sometimes.
A while back i bought myself a GDEMU, and thanks to the lockdown i've started to use it. This is around the time when megavolt85 and yzb started releasing their atomiswave->dreamcast conversions, and their work really got me curious about dreamcast technical documentation, which is in a state, to say the least... I'm seeing a lot of requests for GDI->CDI image conversions in the atomiswave threads, and I'm wondering what the current workflow looks like for such a task. Same goes for vise-versa, where many homebrew games and translations are released in CDI format whereas GDI is now the standard in the era of drive emulators (ODEs). I was trying to read up on this site's mega-FAQ, and I was let-down by the amount of dead links and outdated information. I found a guide on reddit for modifying and repacking CDI files, which seems to be based on a thread from here. I also found some information by megavolt85 on DC-Swat about CDI->GDI, and another comment on reddit by mrneo240 about that process.
I've succeeded in GDI / CDI modifying and repacking, except with CDDA games. I've tried converting MDF/MDS to CDI using a virtual drive and discjuggler, but I always get the "cannot read TOC/PMA" error which makes it impossible. I mostly haven't been able to convert between CDI and GDI either, probably because of "binhacking" issues. It's easy with just IP.bin and one binary, but where there are multiple references and binaries, I haven't succeeded. Are there modern tools besides binhack32 for changing LBA references, or does everyone use hex editors or disassemblers? I've mostly been using file comparison in hex...
I want to ask the community some questions directly:
How does one undo a binhack?
Why is CDDA audio so problematic in disc image creation/conversion? What's the right way to make a GDI with CDDA?
What are the track01 and track02 files in GDI releases? Can they be replicated for a CDI->GDI conversion?
I've amassed way too many tools in the disc image formats quest, just like this post predicted... I hope eventually that the documentation becomes clearer and more visible.
All replies to the thread are welcome, whether you have comments, answers, or more questions! I'm looking forward to building a lasting relationship with the dreamcast.