For the Pong and Snake games, the code that is written is a bootstrap to read values from the controllers and write them to memory. Then it jumps to those routi

For the Pong and Snake games, the code that is written is a bootstrap to read values from the controllers and write them to memory. Then it jumps to those routines. It uses similar techniques to write code to different locations of memory, just like this game credit warp. After the bootstrap code is written, Yoshi eats another Chuck, and the code executes the bootstrap. At this time, the NES reads from the controllers. The controls aren't just your typical controller, as I recall, they are actually multiplexed controller cables plugged in, allowing more bits to be read and thereby written. The code at this point can be anything. Including this [https://youtu.be/bu4Z_-1K_Gw https://youtu.be/bu4Z_-1K_Gw].