http://forums.animesuki.com/showpost...4&postcount=65
For those who are afraid of spoilers: Official name = Play Field Personal
(Then again, when the author himself has problems setting the official english names of H and Elsie, take this with a pinch of salt)
From what I understand, the name PCFX Portable was used by the mangaka only for the oneshot settings. (Do note that the word PFP or PCFX Portable was not mentioned in the oneshot).
I would say it's best not to be too particular on which device does PFP refers to, as it combines elements of both the appearance of Playstation Portable, and the policy towards consoles of NEK(Galgames...).