IBM RT PC Options Installation page 175

IBM PC Graphics Memory Expansion Card
Do the following two steps to install the IBM PC Graphics Memory
Expansion Card, which
will
give the color adapter a total of 128K bytes of
memory.
If
you need to install modules on the expansion card, go to "IBM
PC Graphics Memory Expansion Kit" on page 7-11, install the modules,
and then return to this page.
1. Align the expansion card with the adapter.
2. Press the card and adapter together.
7 -10 Options Installation