INT 10 - EGA Register Interface Library - READ ONE REGISTER
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
SeeAlso: AH=F2h,INT 2F/AX=BC00h

See also: 10F1

10F0 - EGA Register Interface Library - READ ONE REGISTER