A page of Z80 Emulators.
I particularly like Z80-CPU-Emulator (V 5.2b) Full version, Z80 and/or CP/M 2.2 Emulator, By : Joan Riff
I have used the earlier version (3.10) it and it works well. The last time I used it on a PC I got a simulated speed of 25 MHz (IIRC). I tried it with my 2 GHz PC and I got an off the scale reading.
Here is a book I have used. I wonder if I still have my old copy?
Z-80 and 8080 assembly language programming (Hayden computer programming series)
I like the author of this book. I haven't read the book.
Math Toolkit for Real-Time Programming