Apple Performa 6400/180 - Manual (Page 191)

Upgrades Communications Card - 20
If the card does not have
a hook, pass the
external connector
through the hole in the
logic board fence, and
insert the card into the
communications slot.
Press down on the card
until the connector is
solidly in place.
4 Lift gently on the card to
test the connection. If the
card resists and stays in
place, it’s connected.
Communication Slot
Logic Board Fence
Communication Card
Hook