I suspect that you don’t have Mr. Protagonist in mind. He does use his computer in his shared storage unit; and there’s one scene where the eroticism of its optics is described; but Hiro’s interest is in the hardware; and I don’t think he ever actually uses a computer to view porn, though that is mentioned as a thing people can do, in the course of the book:
“The top surface of the computer is smooth except for a fisheye lens, a polished
glass dome with a purplish optical coating. Whenever Hiro is using the machine,
this lens emerges and clicks into place, its base flush with the surface of the
computer. The neighborhood loglo is curved and foreshortened on its surface.
Hiro finds it erotic.”
