I haven't seen the news reported here: http://unibios.free.fr/cdsystem.html Needless to say if it has already been reported feel free to close this thread.
The page makes note that is disables some kind of protection. Does the NeoGeo CD have some kind of protection against running CD-R copies?
For a short answer NGCD has 2 types of protection. One for all kind and one that is CDZ specific. The CDZ specific is encoded at the end of a txt file, while the inGame one requires to edit the relevant binaries (one per protected game). The link above is what I used to crack all mine's, there's a package with all the fixes already, simply use CDMage to apply ;-)
One thing that wasn't explained or maybe I missed it was if with an original CD could you copy it 1:1 and not need to "crack" it? It mentions the protection using the sub-channel but that's about it. It makes no mention if this is something not easily reproduced. Of course it seems like cracking it is quite simple.
I have not tried CloneCD to see if it defeats the protection but non CloneCD images floating around do require the patch. [not sure but if they use wobbling there's no way to create an exact copy as CDR do not have the wobble structure to start with] Keep in mind that there's roughly only 25% of the library protected at all. The patch simply bypass the checks (or inverts them however that may be) so it only defeats the checking part not the mechanism to check itself ... small difference I know but worth pointing out.
If I remember my 68000 correctly the guide is just telling you what operation to replace with a NOP. So it's probably preventing a branch being taken when the check fails. Anyway, it is interesting to see there is some copy protection on specific games on the Neo-Geo CD. I thought it was like other early CD systems.