INT 16 - PC Tools v5.1+ DESKTOP API - GET SCREEN ATTRIBUTE ARRAY
        AX = FFF5h
Return: ES:BX -> screen attributes data structure (see below)
        AL = ??? (v6.0+)

Format of attribute data structure:
Offset  Size    Description
 -1     BYTE    attribute for desktop background
 00h    BYTE    attribute for normal characters on desktop menu
 01h    BYTE    attribute for highlighted characters on desktop menu
 02h  5 BYTEs   ???
 07h    BYTE    attribute for dialog boxes
 08h 15 BYTEs   ???
 17h    BYTE    attribute for message boxes