The original Asteroids arcade hardware, the Atari 8-bit series of computers, and the Commodore 64 all use virtually the same CPU, and they all run at comparable speeds. Norbert Kehrer's Asteroids Emulator takes advantage of this by using the very same code as arcade Asteroids on the Atari and Commodore home computers.

(This screenshot was taken with the Atari800Win emulator.)