IBM 1800409-001A - Manual (Page 291)

4. Place the two shunts on jumpers JP1 and JP2 (fig. 8.22). Make
sure both sets of pins are covered by the shunts.
JP2
JP1
Fig. 8.22 Place the Shunts on the Jumpers
Chapter 8
P r i n t e r O p t i o n s 8 - 3 5