INT 10 - VESA OEM Extensions - Matrox Millenium (BIOS v2.1)

	AX = 4F14h
	BL = function
	    00h installation check / get capabilities
		ES:DI -> 256-byte buffer for Matrox-specific information
			(see #00125)
		Return: ES:DI buffer filled
	    01h read/write MGA indexed data register
		BH = direction (00h = write, else read)
		CL = register number (80h for most-recently used register)
		CH = new value, if writing
		Return: CH = current value, if reading
	    02h read/write register in MGA control space
		BH = direction and size
			bit 4: read register instead of writing
			bits 1-0: data size (00 = BYTE, 01 = WORD, 10 = DWORD)
		SI = register address
		CL/CX/ECX = new value if writing
		Return: CL/CX/ECX = current value if reading
	    03h read PINS byte
		SI = offset of byte within PINS data (see #00126)
		Return: CL = value of specified PINS byte
	    04h ??? (related to PLL programming)
		DX = ???
		Return: CL,EDX destroyed
	    05h read BIOS byte
		SI = offset of byte relative to start of BIOS image
		Return: CL = specified byte
	    else
		Return: AX = FFFFh
Return: AL = 4Fh if function supported
	    AH = status
		00h successful
		01h failed
Note:	most of this info is from http:\\grafi.ii.pw.edu.pl\gbm\matrox
SeeAlso: MEM C000h:7FFCh"Matrox"