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.ax:=$BF03;
    rp.bx:=0;
    rp.cx:=0;
    intr($10,rp):
    if rp.ax=$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