Z80 Assembly 18: Optimizing for T-States (Clock Cycles)
The T-State: Your Ultimate Performance Metric In Z80 programming, the speed of your code isn’t measured in lines, but in T-states (or clock cycles). Every instruction takes a precise, fixed number of T-states to execute. To write fast code, you must choose instructions that minimize this count. Why T-States Matter: If your Z80 runs at 3.5 MHz (as in the ZX Spectrum), 3,500,000 T-states happen every second. A faster instruction in a critical loop can save dozens of T-states every frame, leading to smoother graphics or faster game logic. ...