Function 0F0h   Microsoft Mouse driver EGA support - Read One Register 

entry   AH      0F0h 

	BL      register number 

	DX      group index 

		(pointer/data chips) 

		00h     CRT Controller (25 reg) 3B4h mono, 3D4h color 

		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, 3DAh color 

		30h     graphics 1 position register 3CCh 

		38h     graphics 2 position register 3CAh 

return  BL      data