INT 6F - HP HIL Vectras - EXTENDED BIOS - READ CMOS MEMORY
        AH = 22h
        BP = 0012h (ID of V_SYSTEM driver)
        BL = address of CMOS byte to read
Return: AH = status
        AL = byte read
        BP, DS destroyed
Note:   supported by ES, QS, and RS series HP Vectras
SeeAlso: BP=0012h/AH=24h

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