public static $primary = [ //Number of machine cycles for each instruction: /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F*/ 1, 3, 2, 2, 1, 1, 2, 1, 5, 2, 2, 2, 1, 1, 2, 1, //0 1, 3, 2, 2, 1, 1, 2, 1, 3, 2, 2, 2, 1, 1, 2, 1, //1 2, 3, 2, 2, 1, 1, 2, 1, 2, 2, 2, 2, 1, 1, 2, 1, //2 2, 3, 2, 2, 3, 3, 3, 1, 2, 2, 2, 2, 1, 1, 2, 1, //3 1 machine cycle = 4 clocks x4 cx CALL NZ,a16 3 24/12 - - - - Call address a16 if A register is zero. It takes 24 clocks.