INT 0x10 - 0x0c - Write Graphics Pixel at Coordinate

Request/Call:

reg	value	descr
AH	0x0c
AL		color value (XOR'ED with current pixel if bit 7=1)
BH		page number, see video Pages
CX		column number (zero based)
DX		row number (zero based)

Nothing

if bit 7 is 1, color specified is XOR'ed with current pixel
page number in BH is ignored for 320×200 4 color graphics mode
this function is known to destroy AX and possibly SI and DI on on some PS/2 VGA systems