They very much are synced up, since the PPU needs to generate the video signal directly: https://en.wikipedia.org/wiki/Picture_Processing_Unit https://en.wikipe

They very much are synced up, since the PPU needs to generate the video signal directly: https://en.wikipedia.org/wiki/Picture_Processing_Unit https://en.wikipedia.org/wiki/Picture_Processing_Unit I'm not familiar with the NES in particular, but typically the software is synced with the video signal via hardware interrupts.