That would rule out all the machines not CoCo3, I am not sure if this is the right way to approach the matter, especially since the Z-machine interpreter sources are published now. Someone modified the Atari 8-bit interpreter as well, which lacked z5 for a long time. I am also not sure how many people in the CoCo world actually run Fuzix. Let's say there are options. If someone is able to help me getting the game running with a reasonable target audience on CoCo machines, and with reasonable I mean making it work for most of the CoCo users, I'd be more than happy.