Epson EQUITY 3865X/20 PLUS - Manual (Page 134)

5. T
O
insert the SIMM in the socket, place it on the right side
of the tabs at an angle, as show below.
6. Gently push down on the SIMM and, at the same time, turn
the top of the SIMM to the left until it is vertical and snaps
into place between the tabs and the retaining posts.
SIMM tab
6-14 Installing and Removing Options