IBM 3270 Maintenance Manual page 590

6. Remove any option adapters installed in slot
7 or 8 (5-20-3).
7. Disconnect the power supply connectors from
the system board and move them out of the
way.
8. Look at the figure below and find the Math
Coprocessor on the system board.
o
0
~...--IBMM8th
Coprocessor
October 1984 5-700-3