IBM RT PC Options Installation page 201

Use this table to set the mode switches when any of the following
conditions are present:
• The IBM Personal Computer Enhanced Color Display (5154) is
attached to the Enhanced Graphics Adapter.
• The IBM Personal Computer Enhanced Color Display (5154) is
assigned to the AT Coprocessor Adapter in dedicated mode.
• Another display is also installed and assigned to the AT
Coprocessor Adapter as a second display.
IBM 5154
Display
Assignment
Primary
Primary
Secondary
Secondary
If you need to install the expansion card, go to "IBM PC Graphics
Memory Expansion Card" on page 7-10. If you need to install the
expansion kit, go to "IBM PC Graphics Memory Expansion Kit" on
page 7-12. To install the adapter, go to page 7-13.
IBM 5154 Display
Operating Mode or
Emulation Mode
80 X 25 High
Resolution
80 X 25 Enhanced
Color
80 X 25 High
Resolution
80 X 25 Enhanced
Color
Section 7. Display Adapter Options
Sw1 Sw2 Sw3
Off On On
On On On
Off Off On
On Off On
Sw4
Off
Off
On
On
7-9