For human-interaction...
Modern cost-reduced keyboards require little more than molds & silkscreens. Though we can't have modern "optical" mice with 1980s-era compute, so it seems reasonable to go back to ball-mice.
For output... I think we should be able to manage speakers & (even if incandescent) lights. Black & white CRT-monitors may well become a value-add. I'm assuming that if we can manufacture microchips we can draw a vacuum.
Any further thoughts?
3/3 Fin!