Int 10 Fn F0  - EGA Register Interface Library - Read One Register         [V]

   AH = F0h
   BL = register number
   BH = 00h
   DX = group index
       Pointer/data chips
          00h CRT Controller (25 reg) 3B4h mono modes, 3D4h color modes
          08h Sequencer (5 registers) 3C4h
          10h Graphics Controller (9 registers) 3CEh
          18h Attribute Controller (20 registers) 3C0h
       Single registers
          20h Miscellaneous Output register 3C2h
          28h Feature Control register (3BAh mono modes, 3DAh color modes)
          30h Graphics 1 Position register 3CCh
          38h Graphics 2 Position register 3CAh

Return: BL = data

Note:  the RIL is provided by EGA.SYS, the Microsoft Mouse driver, the OS/2
     compatibility box, and others

See Also: AH=F1h,AH=F2h,INT 2F/AX=BC00h