IBM RS/6000 7043 43P Series - Page 205

3. If you have a Model 150, locate the SCSI security jumpers in the following figure.
J35
J36
4. To disable the external SCSI connector for the Model 150, move the jumper on
J35 to the front two pins, and move the jumper on J36 to the rear two pins.
Chapter 4. Installing and Removing Options 4-103