Comparing the Z80 and 6502 to Their Relatives

A deep-dive comparison of classic 8-bit and 16-bit CPU architectures: the Intel 8080, Z80, 8086, Motorola 6800, 6809, and MOS 6502. The post traces the lineage and design philosophy of each chip, highlighting key differences in register sets, memory addressing modes, stack capabilities, and instruction encoding. It also revisits earlier assembly programming maxims for the 6502 and Z80, evaluating which advice still holds and adding new insights — notably that Z80 code is often faster when it's also valid 8080 code. Toolchain recommendations (NASM, Pasmo, WLA-DX, asm6809) are included for each architecture family.