Epson EL 3S/33 - Manual (Page 59)

4. Position the coprocessor over the socket as shown below.
Align the notched corner of the coprocessor (marked with
a dot) over the corresponding comer in the socket.
notched
corner
Be sure to align the pins in the coprocessor directly over
the holes in the socket. If you insert the math coprocessor
in the wrong position, you could permanently damage it.
5. Make sure the pins in the coprocessor are directly over the
holes in the socket. Then gently push the coprocessor
straight into the socket, pressing evenly on all sides.
6. Replace any option cards you removed. See page 3-13.
Post-installation Procedures
After you install or remove options such as memory modules
or a math coprocessor, you must run SETUP to update the
computer’s configuration. See Chapter 1 for instructions.
Additionally, you may need to add some commands to your
configuration files. See your operating system manual and the
manual that came with your optional equipment.
3-20 Installing and Removing Options