Function 1Ah Display Combination Code (MCGA, VGA)
Using the compatibility BIOS of the PS/2 Models 50, 60, 80 there
is a way to determine which video controller and attached
display are on the system. The Display Combination Code (DCC)
is a Video BIOS function that provides the capability.
entry AH 1Ah
AL 00h read display combination code
01h write display combination code
return AL 1Ah indicates Compatibility BIOS is supported,
any other value is invalid
BH Display Combination Code (DCC)
00h no display
01h IBM monochrome adapter and display
02h IBM color/graphics monitor adapter w/color display
03h reserved
04h IBM EGA, color display
05h IBM EGA, monochrome display
06h IBM PGA, color display
07h VGA, analog monochrome display
08h VGA, analog color display
09h reserved
0Ah MCGA, digital color display
0Bh MCGA, analog monochrome display
0Ch MCGA, analog color display
0FFh unknown display type
BL active display device code
note This function may be used to test for VGA, since it is not supported in
earlier adapters. If AL is still 1Ah when the call completes, a VGA
compatible adapter is present.