IBM RT PC Options Installation page 162

TNL SN20-9864 (May 1987) to 75X0217
Instal/ing:
You may install this adapter in slots 2, 4, 5, 7, and 8 in Model 25
and in slots 2 through 5 in Model 10, whichever is available. See the system
unit diagram for the correct slot.
An mM Token-Ring Network RT PC Adapter with the address range
11 CO - 11 CF may
not
be installed in slot 8 of Model 25 or in slot 5 of
Model 10.
Section 6. Communication and Network Adapter Options 6-29