Great news. A MAMEdev (not Aaron or Nicola) has broken the ZN encryption using some specialized hardware. This means that potentially all ZN games (including previously unsupportable ones like Raystorm or NBA Jam Extreme) could be supported now. However, for each individual game we need a dump from it's encryption chip (there is 2048 bytes of "key data" necessary to "turn the lock"). Guru has set up a status page showing what keys are dumped and which ones we'll probably still need PCBs for. If you have any of the missing PCBs and can send 'em off for a bit, please either post here or contact Guru directly. Guru\'s ZN status list
In addition to what's shown there, we also have a Psychic Force and a Heaven's Gate in "safe hands".