IBM RT PC Options Installation page 125

TNL SN20-9864 (May 1987) to 75X0217
Installing Memory Options
CAUTION
Turn off the power on the system unit and unplug the power cable from
the electrical outlet.
If you have not removed the covers, see "Removing the Covers From the
System Units" on page 1-4.
Memory option slot assignments differ, depending on which memory option
or combination of memory options you choose.
Refer to "General Instructions" on page 3-4 when necessary for
information on installing adapters.
5-4 Options Installation