IBM RT User's Setup Manual page 199

2-24 Options Installation
Use the following steps to install the fixed-disk drive in position D:
1. Remove the cooling fan assembly. See "Cooling Fan Removal"
on page 2-5.
Warning: Do not bend the pins!
2. Remove the terminator resistor(s) by pulling the paper tab(s), if
present, or by inserting a small, flat-bladed screwdriver under
the resistor. Carefully pry up alternate ends of the resistor(s) to
lift evenly.
Note: IBM 310 megabyte fixed-disk drives may look like either
of the bottom two examples below.
Selection
Jumper
AJZIF221