"The removal of the parallel port was probably partly because no official add-on had ever been released for it, and partly because it was being used to connect cheat cartridges that could be used to defeat the regional lockouts and copy protection." [http://en.wikipedia.org/wiki/PlayStation_%28console%29|from here] I guess at the time Sony had some ides of using it for expansion and different controllers but later abandoned the plan. Hope this helps...