--------V-104E00-----------------------------
INT 10 - VESA XGA BIOS Extensions - GET XGA ENVIRONMENT INFORMATION
	AX = 4E00h
	ES:DI -> 256-byte buffer for XGA information (see #00069)
Return: AL = 4Eh if function supported
	    AH = status
		00h successful
		else error code
Desc:	determine whether VESA XGA extensions are present and the capabilities
	  supported by the display adapter
SeeAlso: AX=4E01h,AX=4E02h,AX=4F00h
Index:	installation check;VESA XGA

Format of XGA information buffer:
Offset	Size	Description	(Table 00069)
 00h  4 BYTEs	signature ("VESA")
 04h	WORD	VESA version number
 06h	DWORD	pointer to ASCIZ OEM string
 0Ah	DWORD	environment flags (see #00070)
 0Eh	WORD	number of XGA adapters installed (other VESA XGA functions
		  require a handle indicating which adapter to use)
 10h 240 BYTEs	reserved

Bitfields for XGA environment flags:
Bit(s)	Description	(Table 00070)
 0-1	system bus (00 = MCA, 01 = ISA, 10 = EISA)
 2	bus mastering available
 3-31	reserved
--------V-104E01----------------------------
INT 10 - VESA XGA BIOS Extensions - RETURN XGA SUBSYSTEM INFORMATION
	AX = 4E01h
	DX = XGA handle (0 to number of XGAs-1)
	ES:DI -> 256-byte buffer for subsystem information (see #00071)
Return: AL = 4Eh if function supported
	AH = status
	    00h	 function successful
	    else error code
SeeAlso: AX=4E00h,AX=4E02h

Format of XGA subsystem information:
Offset	Size	Description	(Table 00071)
 00h	DWORD	pointer to null-terminated board OEM string
 04h	DWORD	capabilities (see #00072)
 08h	DWORD	pointer to 8KB XGA ROM (or NULL)
 0Ch	DWORD	pointer to the XGA memory mapped registers
 10h	WORD	base address of XGA I/O registers (21x0h)
 12h	DWORD	pointer to start of physical video memory
		(A000h:0000h or B000h:0000h)
 16h	DWORD	physical address of 4MB aperture (or NULL if none)
 1Ah	DWORD	physical address of 1MB aperture (or NULL if none)
 1Eh	DWORD	physical address of 64KB aperture (or NULL if not enabled)
 22h	DWORD	physical address of OEM aperture (or NULL if none)
 26h	WORD	size of OEM aperture in 64KByte units
 28h	DWORD	pointer to list of video modes
		The list is a series of WORDs terminated by FFFFh
 2Ch	WORD	number of 64KB blocks on the board
 2Eh	DWORD	XGA manufacturer ID
		byte 0 POS data index 1
		byte 1 is index 2
		byte 2 is 21xAh index 75h
 32h 206 BYTEs	reserved

Bitfields for XGA capabilities:
Bit(s)	Description	(Table 00072)
 0-1	board bus architecture: 0=MCA, 1=ISA, 3=EISA
 2-3	reserved
 4-6	DMA Channel assigned for acquiring bus mastership (only for ISA bus)
 7	DMA Channel Status (ISA only). enabled if set
 8-31	reserved
--------V-104E02-----------------------------------
INT 10 - VESA XGA BIOS Extensions - RETURN XGA MODE INFORMATION
	AX = 4E02h
	CX = Video mode
	DX = XGA handle
	ES:DI -> 256 byte buffer for mode information (see #00073)
Return: AL = 4Eh if function supported
	AH = status
	    00h	 function successful
	    else error code
SeeAlso: AX=4E00h,AX=4E01h

Format of XGA mode information:
Offset	Size	Description	(Table 00073)
 00h	WORD	attributes of the mode (see #00074)
 02h	WORD	bytes per logical scanline
 04h	WORD	horizontal resolution in pixels
 06h	WORD	vertical resolution in scanlines
 08h	BYTE	character Width in pixels
 09h	BYTE	character Height in pixels
 0Ah	BYTE	number of planes
 0Bh	BYTE	bits per pixels
 0Ch	BYTE	memory model (see #00075)
 0Dh	BYTE	number of Image Pages
 0Eh	BYTE	number of Red bits
 0Fh	BYTE	bit position of Red bit field
 10h	BYTE	number of Green bits
 11h	BYTE	bit position of Green bit field
 12h	BYTE	number of Blue bits
 13h	BYTE	bit position of Blue bit field
 14h	BYTE	number of Reserved bits
 15h	BYTE	bit position of Reserved bit field
 16h 235 BYTEs	reserved

Bitfields for XGA mode attributes:
Bit(s)	Description	(Table 00074)
 0	set if mode is supported
 1	reserved
 2	output is supported by the BIOS
 3	reserved
 4	if set this is a graphics mode (VGA registers inactive, XGA active),
	  if clear this is a text mode (VGA registers active, XGA inactive)

(Table 00075)
Values for XGA video memory model:
 00h	Text Mode
 01h	CGA graphics
 02h	Hercules graphics
 03h	4-planar graphics
 04h	Packed Pixel
 05h	Non-chain 4, 256 color
 06h	Direct Color
 07h	YUV-24
--------V-104E03-----------------------------------
INT 10 - VESA XGA BIOS Extensions - SET XGA VIDEO MODE
	AX = 4E03h
	BX = video mode
	CX = other command flags
	     bit 0  If clear the feature connector is set to the default state
	DX = XGA handle
	ES:DI -> 256 byte buffer
Return: AL = 4Eh if function supported
	AH = status
	    00h	 function successful
	    else error code
SeeAlso: AH=00h,AX=4E04h,AX=4F02h
--------V-104E04-----------------------------------
INT 10 - VESA XGA BIOS Extensions - RETURN CURRENT VIDEO MODE
	AX = 4E04h
	DX = XGA handle
Return: AL = 4Eh if function supported
	AH = status
	    00h	 function successful
		BX??? = current mode
	    else error code
SeeAlso: AH=0Fh,AX=4E03h,AX=4F03h
--------V-104E05-----------------------------------
INT 10 - VESA XGA BIOS Extensions - SET FEATURE CONNECTOR STATE
	AX = 4E05h
	BX = Feature Connector State (see #00076)
	DX = XGA handle
Return: AL = 4Eh if function supported
	AH = status
	    00h	 function successful
	    else error code
SeeAlso: AX=4E00h,AX=4E06h

Bitfields for XGA Feature Connector State:
Bit(s)	Description	(Table 00076)
 0	Feature Connector is enabled
 1	Feature Connector is in Output Mode rather than Input Mode
 2-15	reserved (0)
--------V-104E06-----------------------------------
INT 10 - VESA XGA BIOS Extensions - RETURN FEATURE CONNECTOR STATE
	AX = 4E06h
	DX = XGA handle
Return: AL = 4Eh if function supported
	AH = status
	    00h	 function successful
	    else error code
	BX = Feature Connector State (see #00076)
SeeAlso: AX=4E00h,AX=4E05h 