IBM RT PC Options Installation page 49

TNL SN20-9864 (May 1987) to 75X0217
Use the following steps to install the fixed-disk drive in position C:
Warning: Follow
all instructions under "Removing the Covers from the
System Units" on page 1-4 before installing the drive in position C.
1. Remove the cooling fan assembly. Refer to "Cooling Fan Removal"
on page 2-6.
2. Use the following illustration to identify which drive you are
installing.
TypeR40 /
Type R70 or E70
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/
3. Check the drive selection jumper or switches for the correct setting
and make sure the terminating resistor is present on the drive.
2-12 Options Installation
Drive
Selection
Jumper
Setup Switches