Tetris: Speedhack

This hack effectively changes the framerate of the NES, which allows for some very interesting speed options for Tetris.

This hack converted Tetris from MMC1 to MMC3 to take advantage of its *scanline counter*, which lets it schedule polls at arbitrary intervals with remarkable precision. To help facilitate this, the code was optimized by a factor of 3, now spending less than 10 percent of a frame actually executing logic compared to the original 30 percent.

Currently it can divide the frame into 6 equal parts without running into issues, which allows for plenty of speeds to experiment with, like 72hz (6/5), 100hz (5/3), and even 360hz (6/1) if you're feeling adventurous.

Database match: Tetris (USA)
Database: No-Intro: Nintendo Entertainment System (v. 20210216-231042)
File SHA-1: 77747840541BFC62A28A5957692A98C550BD6B2B
File CRC32: 6D72C53A
ROM SHA-1: FD9079CB5E8479EB06D93C2AE5175BFCE871746A
ROM CRC32: 1394F57E