Compaq Super VGA chips.


    3CEh index  Fh:
	writing 5 to this register unlocks the extended registers.

    3CEh index 45h: Bank register
    bit 0-7  Bank number in 4k blocks.



    ID Compaq super VGA:

    rp.bx:=0;
    rp.cx:=0;
    vio($bf03):
    if rp.ax=$BF03 then Compaq.


    Video Modes:

    2Eh G 640x480  256c  packed
    59h G 800x600   16c  planar


  Compaq BIOS extensions:

----------10BF00-----------------------------
INT 10 - VIDEO - Compaq Portable Extensions - SELECT EXTERNAL MONITOR
	AX = BF00h
Note: all registers preserved and the internal monitor is blanked
      the external monitor becomes the active monitor
SeeAlso: AX=BF01h
----------10BF01-----------------------------
INT 10 - VIDEO - Compaq Portable Extensions - SELECT INTERNAL MONITOR
	AX = BF01h
Note: all registers preserved and the external monitor is blanked
      the internal monitor becomes the active monitor
SeeAlso: AX=BF00h
----------10BF02-----------------------------
INT 10 - VIDEO - Compaq Portable Extensions - SET MASTER MODE OF CURRENT CTRLR
	AX = BF02h
	BH = master mode
	    04h CGA
	    05h EGA
	    07h MDA
SeeAlso: AX=BF03h
----------10BF03BX0000-----------------------
INT 10 - VIDEO - Compaq Portable/Systempro Extensions - GET ENVIRONMENT
	AX = BF03h
	BX = 0000h
Return: BH = active monitor
	    00h = external
	    01h = internal
	BL = master mode
	    00h = switchable VDU not present
	    04h = CGA
	    05h = EGA
	    07h = MDA
	    08h = switchable LCD controller present
	CH = 00h (reserved)
	CL = switchable VDU mode supported
	    bit    0 = CGA supported
	    bits 1,2 = reserved (1)
	    bit    3 = MDA supported
	    bits 4-7 = reserved (1)
	DH = internal monitor type
	    00h = none
	    01h = Dual-mode monitor
	    02h = 5153 RGB monitor
	    03h = Compaq Color monitor
	    04h = 640x400 flat panel
	    07h = LCD VGA
	DL = external monitor type
	    00h = none
	    01h = dual-mode monitor
	    02h = 5153 RGB monitor
	    03h = Compaq Color monitor
	    04h = 640x400 flat panel
	    05h = VGC monochrome
	    06h = VGC color
SeeAlso: AH=1Ah,AX=BF00h,AX=BF01h,AX=BF02h
----------10BF04-----------------------------
INT 10 - VIDEO - Compaq Portable Extensions - SET MODE SWITCH DELAY
	AX = BF04h
	BH = new state of delay
	     00h enabled
	     01h disabled
SeeAlso: AX=BF05h
----------10BF05-----------------------------
INT 10 - VIDEO - Compaq Systempro Extensions - ENABLE/DISABLE DISPLAY
	AX = BF05h
	BH = new state of video
	     00h off
	     01h on
SeeAlso: AX=BF04h
----------10BF06-----------------------------
INT 10 - VIDEO - Compaq SLT/286 - READ GRAY SCALE TABLE
	AX = BF06h
	CL = address to be read from gray scale table
Return: AL = bit 3-0 - Value read from gray scale table
	CL = address to be read from gray scale table
SeeAlso: AH=12h/BL=33h,AX=BF07h
----------10BF07-----------------------------
INT 10 - VIDEO - Compaq SLT/286 - WRITE GRAY SCALE TABLE
	AX = BF07h
	CH = value to write to gray scale table
	CL = address to be written to gray scale table
SeeAlso: AX=BF06h
----------10BF08-----------------------------
INT 10 - VIDEO - Compaq SLT/286 - WRITE COLOR MIX REGISTERS
	AX = BF08h
	CH = bits 7-4 - Green weight
	     bits 3-0 - Blue weight
	CL = bits 7-4 - unused
	     bits 3-0 - Red weight