AZM Book 1 — Z80 Fundamentals
This book starts from no prior knowledge of computers or programming. It introduces the Z80 from the bare machine upward: memory, registers, machine code, assembly language, flags, loops, tables, the stack, subroutines and port I/O.
The later chapters introduce the AZM features that make assembly programming more maintainable: subroutine conventions, register contracts, layout types and op declarations.