Specifications

190 AMD Geode™ GeodeROM Functional Specification
Video BIOS Support
32087C
13.1.21 Function 1Ah - Get DCC Information
Description:
Sets or returns the display combination code (DCC). A DCC is used to indicate a combination of two monitors in the
system. For example, a common combination is VGA color with a co-resident monochrome display adapter. This func-
tion was not on the EGA and therefore has been used as a test for the existence of a VGA in the system.
Display
Type Description
00h No Display
01h Monochrome Display Adapter (MDA)
02h Color Graphics Adapter (CGA)
03h Reserved
04h Monochrome Enhanced Graphics Adapter (Mono EGA)
05h Color Enhanced Graphics Adapter (Color EGA)
06h Professional Graphics Adapter (PGA)
07h Monochrome Video Graphics Array (Mono VGA)
08h Color Video Graphics Array (Color VGA)
09h Reserved
0Ah Reserved
0Bh Monochrome MCGA
0Ch Color MCGA
Passed:
Returns:
Parameter Description
AH 1Ah = Function number
AL DCC subfunction:
0 = Get DCC
1 = Set DCC
BL Active display code (when AL = 1)
BH Secondary display code (when AL = 1)
Parameter Description
AL 1Ah
BL Active display code (when AL = 0)
BH Secondary display code (when AL = 0)