INT 10 - VESA SuperVGA BIOS v1.1 - GET/SET DISPLAY START
AX = 4F07h
BH = 00h (reserved)
BL = 00h set display start
CX = leftmost displayed pixel in scan line
DX = first displayed scan line
= 01h get display start
Return: BH = 00h
CX = leftmost displayed pixel in scan line
DX = first displayed scan line
Return: AL = 4Fh if function supported
AH = status
00h successful
01h failed
Note:   this function is valid in text modes, provided that values are
multiplied by the character cell width/height
SeeAlso: AX=4F05h,AX=4F06h

See also: 104F01

104F07BH00 - VESA SuperVGA BIOS v1.1 - GET/SET DISPLAY START