Anyone skilled in disassembling PC programs like the Casio image converter? Because I'm not...
And Simon doesn't seem to be interested in reverse-engineering the CAPTURE routine.

In the worst case, this could take us another year.

The Prizm OS detects the CG10 via syscall 0x1196, which checks for the byte at 0xA0000305 to be 0x5A.
When opening a g3p-file the "Invalid Type"-message (msgno 0x3E) appears, if syscall 0x1196 detects a CG10.

Hence a byte inside of syscall 0x1196 would have to be modified.
At the moment I do not see another way to bypass the CG10-restriction.

BTW: I'd rather not think about changing the byte at 0xA0000305.

I have another idea:
Instead of cracking the image checksum and changing the type ID (which is hopefully not required for decompression, because this would mean complete repackaging using zlib), couldn't we just modify the image converter to write the ID 0x3C1B instead of 0x789C before the checksum calculation takes place? Worth a try...

Holy crap, the image converter does not seem to be protected.

That might work, but this method is likely to be troublesome because of legal issues. Casio's converter is tricky to get, and I'm not sure if patching it is allowed.

So you wrote the first OS modifying add-in? Casio learnt nothing...

Hopefully it is possible to convert images between both models in the future. The French Casio community is growing larger, but most people use BASIC for their games. As a result, about 50% of the existing PRIZM games only work on european models. :'(

I would actually like a tool to view calc images on the PC, like TI-Connect has. It's annoying to have to open a copy of the emulator then import the files to view them. X.x

I meant one that is actually available for download for everyone (although Casio might not like that if the said tool can edit/save/compress images)

Apparently the hacking of the g3p/b format topic seems to have made a group of Casio PRIZM coders in the calculator community worried, because of the consequences the release of such tool could cause to the Casio PRIZM community. Although I have good faith that anybody posting in this thread want this tool to be used only for program development or to allow Planète-Casio BASIC games to be played on american PRIZM models, if this tool gets released publicly or even in the spam forum (which requires 500 posts), it will inevitabely fall under the wrong hands, eventually.

Personally, the only way around this that I thought is that once released, a trusted TI community member volunteers to convert images destined for programming use themselves, upon programmer/gamer requests, and that this person never release the tool anywhere. Otherwise, if released, I guarantee you that eventually someone will use it to cheat in tests or to stock porn in his calc. And even if that was to never happen, Casio will most likely worry that it will, and their reaction might be to lock down their calcs even more, potentially at the detriment of you good guys making games and useful tools for all of us. And sadly, Omnimaga and Cemetech did encounter their share of students asking help to cheat on tests before ( http://ourl.ca/15055 being an example, and see Calc84maniac's sarcastic response), and it was most likely even worse on other calc sites that aren't as programming-oriented as us, so even if that tool was only released privately to any member above 1000 posts, I am sure eventually it could lead to bad consequences. And this would be the last thing the community wants, especially when there are people trying to strenghten relations between Casio and the community.

The problem, though, is would anybody ever be willing to volunteer for converting people's pics himself (and filtering innapropriate ones)? My idea is that the pic request requires a link to the user's project in the works or a link to a FX-cg20-only game that he needs converted, so the person doesn't receive too many requests, but even then I worry this could be tedious for the person.