I wanted to play the original Prince Of Persia without ROMs and I did find it

Prince of Persia reimplementation written in HTML5 / JavaScript (MS-DOS version)

I just can't believe how good this game is and how well it has lasted through time! Everything just works; game play, atmosphere, music and even the plot. Give it a try just to see how things looked in 1989. I'm currently at level 6.