Epson EQUITY 3865X/20 PLUS User Manual page 141

3. The math coprocessor socket is hollow and square. The
upper right comer of the socket is notched, as shown below.
There is also a notched comer on the math coprocessor, as
shown below.
Align the notched comer of the coprocessor with the
notched comer of its socket. The notched comers must be
aligned for the coprocessor to fit into the socket, so be sure
the alignment is correct before you proceed to the next step.
Caution
If you insert the math coprocessor in the wrong position,
you could permanently damage it.
notched corner
notched corner
Installing and Removing Options
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