Int 10 Fn CD07  - Video - Ultravision V1.2+ - Set Underline Status (ega,v  [V]

   AX = CD07h
   CL = hardware underline status (see #0153)
   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

See Also: AX=CD08h

(Table 0153)
Values for hardware underline status:
 00h   off (color systems only)
 01h   underline below characters
 02h   strike through characters