INT 10 - VIDEO - UltraVision v1.2+ - SET UNDERLINE STATUS (EGA,VGA)
        AX = CD07h
        CL = hardware underline status
            00h off (color systems only)
            01h underline below characters
            02h strike through characters
        BL = foreground color for normal text (FFh = current)
        BH = foreground color for bright text (FFh = current)
Return: CL = hardware underline status
        BL = current foreground color for normal text
        BH = current foreground color for bright text
Notes:  when underline or strikeout is enabled in color text modes, the
          specified colors will be assigned temporarily to colors 01h and 09h,
          allowing affected text to match non-underlined text.  The color
          remapping uses values from the current onscreen palette regardless
          of the palette locking status (see AX=CD01h)
        specify the standard colors (BL=01h,BH=09h) to enable underline or
          strikeout without color remapping