Int 10 Fn 6F01  - Video - Video7 VGA,vega Vga,hp Ext BIOS - Get Monitor I  [V]

   AX = 6F01h

Return: AL = monitor type code (HP,VEGA VGA only) (see below)
   AH = status register information
        bit  0 = display enable
           0 = display enabled
           1 = vertical or horizontal retrace in progress
        bit  1 = light pen flip flop set
        bit  2 = light pen switch activated
        bit  3 = vertical sync
        bit  4 = monitor resolution
           0 = high resolution (>200 lines)
           1 = low resolution (<=200 lines)
        bit  5 = display type
           0 = color
           1 = monochrome
        bits6,7= diagnostic bits
   CL = current value of Extended Control register (HP Ext BIOS, and only
       if AL=41h)

Note:  bits 0-3 are the same as the EGA/VGA status register bits 0-3

Values for monitor type code (HP Extended BIOS):
 00h   non-HP card with ROM and possibly its own INT 10h driver
 41h   MultiMode video display adapter
 42h-44h reserved
 45h   industry standard monochrome display adapter
 46h   industry standard color display adapter
 51h   reserved