tepples wrote:At least under U.S. trademark and copyright law as interpreted in Sega Enterprises v. Accolade, displaying the required Nintendo trademark in the BIOS intro is perfectly OK as long as you clearly disclaim Nintendo's sponsorship or endorsement. Put "Not sponsored or endorsed by Nintendo" where most games would say "Licensed by Nintendo".
(The core holdings of Sega have been upheld post-DMCA as Chamberlain v. Skylink and Lexmark v. Static Control.)
This applies to GB, GBC, GBA games, but for NDS games you can and should still put "Not sponsored or endorsed by Nintendo", but you don't need the Nintendo logo in the header. But, if you put the game in a DS game card then you still have to use the correct encryption, but that should be OK as well.
I think Datel DS cards can be rewritable with any software less than 512K, so if it is small enough you can rewrite one of those, remove the Datel label and replace with your own. Of course, it may be expensive unless Datel allows discount for purchasing in bulk