> > So while trying the latest Kega, which is awesome btw, I found a "disable
> SRAM"
> > function, and it made the copy-protection code fail. Hooray ! But still there
> > are many unanswered questions here...
>
> My guess: the games tries to write to SRAM. Impossible on an original cart with
> no SRAM (=> original game, go ahead), possible with copiers that simulated SRAM
> in some way to allow SRAM games to save (=> lock the game). And easy, free
> protection mechanism, as long as copiers cannot turn off SRAM saving.

Some modern GBA games work the same way - the NES Classics, for example.