NEC PowerMate V486 Series Manual page 145

Align the notched end of the SIMM with the correct
end of the SIMM socket (see the following figure).
Insert the SIMM at an angle into the socket.
!
CAUTION: Be sure to install the SIMMs
in the correct sockets.
Carefully tilt the SIMM towards the locking tabs.
Using equal pressure at the ends of the SIMM, push
it until it locks under the metal clips at the ends of the
socket.
!
CAUTION: Be careful when handling
the SIMM. The SIMM and socket tabs are fragile.
Inserting the SIMM
Adding Options 5-29