HP C100/110 Owner's Manual page 207

Trying to change the monitor type on an empty slot, fails and gives you this
warning message:
Configuration Menu: Enter command >
MONITOR INFORMATION
WARNING: Intended graphics hardware does not exist.
Be sure to install the hardware after you power down the system.
Slot # HPA
--------- -------
graphics3 f4000000
graphics4 f6000000
Current Console Path:
Stable Store Console Path:GRAPHICS3
Table 26 shows the possible combinations of graphics cards and slots.
Graphics 3, and Graphics 4 refer to the console paths, GRAPHICS3, and
GRAPHICS4, respectively. There is no GRAPHICS 1 or GRAPHICS 2
path. Configurations 6 and 7 use the GRAPHICS3 path even though the
Geometry Accelerator card is in slot 4.
The abbreviations in the table represent the following:
"S", a color graphics or Hyperdrive series graphics card
"D", a dual color graphics card
"V", a VISUALIZE-48 graphics card
Displaying and Setting the Monitor Type
State Resolution
---- ----------
Present Fixed
Empty
core.RS232_.9600.8.none
The Boot Console Interface
monitor graphics4
Frequency Class
--------- -------
191