Compatibility: VGA
Expects: AX    1013H
BL    subfn: 00H = select color paging mode
BH = paging mode
00H = 4 blocks of 64 registers
01H = 16 blocks of 16 registers

BL    subfn: 01H = activate color page
BH = DAC color page number
00H-03H (4-page/64-reg mode)
00H-0fH (16-page/16-reg mode)
                                                                  
Returns: (none)
                                                                  
Info: This lets you choose a DAC color-paging mode to enable groupings
of color registers.  It also lets you activate a particular DAC
register page.

Text-mode users will prefer 16-color paging mode (BX=0100H),
making it possible to quickly map any of 16 color set to the 16
possible text-mode attribute colors.

For instance, imagine setting up 16 groups with gradually-
increasing brightness of all colors.  Then you could cycle
through the groups (BX=0001H, BX=0101H, BX=0201H...) to brighten
or dim the entire screen.

Notes: Use INT 10H 101aH (query color paging state) to obtain the
current settings.

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INT 10H 1013H: DAC Color Paging Functions