INT 10 - Cirrus Logic BIOS - SET MONITOR TYPE
        AH = 12h
        BL = A4h
        AL bits 3-0 = maximum vertical resolution
                (0 = 480 scanlines, 1 = 600, 2 = 768, 3 = 1024, other reserved)
        AL bits 7-4 = vertical refresh at 640x480
                (0 = 60Hz, 1 = 72Hz, other reserved)
        BH bits 3-0 = vertical refresh at 800x600
                (0 = 56Hz, 1 = 60Hz, 2 = 72Hz, other reserved)
        BH bits 7-4 = vertical refresh at 1024x768
                (0=87Hz-int, 1=60Hz, 2=70Hz, 3=72Hz, 4=76Hz, other reserved)
        CH bits 4-7 = vertical refresh at 1280x1024
                (0=87Hz-int, 1=60Hz, 2=70Hz, other reserved)
SeeAlso: AH=12h/BL=9Ah,AH=12h/BL=A3h

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