Did you know that there are emulators out there for old games? Modern PCs are so much faster than 1980 arcade machines that they can run programs to interprete the old arcade games. So you can play the actual game on your pc and it will play exaclty the same. You just have to somehow get the code from the original arcade machine processor chips.
Companies like Atari don't release the code since its still valuable to them. So its not legal to give them away. But they are all over the internet. YOu just have to search for them.