HP 98568A Installation Instruction page 107

HP 98546A Display Compatibility Interface
b. Set the 50/60 Hz switch to the desired setting by referring to Figure 5-4.
3. Set the Character Select Switch.
SKIP?
If you are not using Japanese characters, you can skip to step
4. The character select switch is preset to ASCII/Roman 8 and
need not be changed.
a. Find the character select switch on the video card (see Figure 5-4).
b. Set the character select switch to ASCII/Roman 8 or ASCII/Katakana
by referring to Figure 5-4.
4. Insert the Interface.
a. If the graphics and video cards are not already connected together, plug
the ribbon cable connector on the graphics card cable into the matching
connector on the video card. The connector is designed so you cannot
insert it backwards.
b. Remove the painted cover plates from the back of your computer
until you find two adjacent empty slots. The bottom slot must be an
even-numbered slot. (Slots are numbered from the top down, so the
top-most slot is number 1, the next slot down is number 2, etc.) Do not
remove the silver cover plates from the bottom of a Series 300 computer.
c. Hold the interface with the graphics card above the video card. Make
sure the components are facing up.
d. Keeping the graphics card slightly ahead of the video card, slide the
cards into adjacent accessory slots as shown in Figure 5-5.
Adding Interface Cards 5-11