his second game, "prince of persia", was released in 1989 after more than three years of work. he wrote both games in 6502 assembly language for the apple ii, though that system was in decline through the late 1980s and little new software was released by 1989. initially "prince of persia" sold poorly, but as it was ported to other systems sales increased. eventually it was adapted for nearly every computer and console platform.