Epson 4SLC2-50 - Manual (Page 74)

2. Place the coprocessor over the socket so that the round
indentation indicating pin 1 is in the upper left corner. Then
push it down into the socket.
3. Replace the keyboard as described in the next section.
The computer automatically detects when’s coprocessor is
installed. When you turn on the computer, the system
configuration screen shows that a numeric coprocessor is present.
Caution
If you need to remove the math coprocessor, do not try to do it
yourself. This procedure requires a special extraction tool.
Contact your Authorized Epson Servicer.
Connecting Optional Devices 4-17