[gp2000]

Though it'll still be kinda slow on a Model I, I've written an about 9 times faster Z-80 code for the network evaluation. I imagine the pull request will end up in the main depot but for now you can find it in https://github.com/gp48k/z80ai

I think I can do a little bit better; maybe 10% faster.

[gp2000]

Well, I was pessimistic. Just pushed an update that slightly more than doubles the execution speed with a PR to the main depot pending. It is very close to 20 times faster than the original.