Writing Z80 assembly, 4 decades later:-)

A developer successfully ported 3D graphics rendering software from an ATmega328P microcontroller to a ZX Spectrum computer from the 1980s by rewriting the code in optimized Z80 assembly language. Through techniques like replacing divisions with reciprocal lookup tables and pre-computing screen memory writes, they achieved frame rates ranging from 14 fps in hand-optimized assembly to 40 fps in the fully pre-computed version, dramatically outperforming the original C implementation at 6.2 fps.