Int 10 Fn 12  - Video - Xga - Mainframe Interactive Support                [V]

   AH = 12h
   BL = 37h
   AL = text attribute type (00h normal VGA, 01h mainframe type)

Return: AL = 12h if supported

See Also: #0025,AH=08h,#0040

Bitfields for XGA mainframe type character attributes:
Bit(s) Description (Table 0025)
 7 blink double rate (75% ON time) or use color 8 as background
   (see AX=1003h)
 6 reverse video
 5 underlined
 4 left-most and right-most dots of underline area inverted
 3 foreground intensity/character font select
 2-0   foreground color

See Also: #0013,#0034